Scopus EXPORT DATE:18 Apr 2023 Cheng, J., Park, J.H., Wu, Z.-G. A hidden Markov model based control for periodic systems subject to singular perturbations (2021) 157, art. no. 105059, . Cited 35 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117904060&doi=10.1016%2fj.sysconle.2021.105059&partnerID=40&md5=03ae82718ea65bc04610ad8dbfe1dd8c DOI: 10.1016/j.sysconle.2021.105059 AFFILIATIONS: School of Mathematics and Statistics, Center for Applied Mathematics of Guangxi, Guangxi Normal University, Guilin, 541006, China; Department of Electrical Engineering, Yeungnam University, 280 Daehak-Ro, Kyongsan, 38541, South Korea; School of Information Science and Engineering, Chengdu University, Sichuan, Chengdu 610106, China; State Key Laboratory of Industrial Control Technology, Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027, China ABSTRACT: This study analyzes the problem of hidden Markov model based control for periodic systems subject to singular perturbations and Lur'e cone-bounded nonlinearity. Different from the existing time-invariant fading channels, the fading channels are alleviated to be time-varying. Furthermore, to better depict the time-varying property of the fading channels, a novel periodic Markov process framework subject to mean and variance is developed. The highlight of this study lies that the hidden Markov model detector is forwarded to observe the fading channel mode, whose detection probabilities are generalized to be partially recognized. New techniques are developed in dealing with the stochastic Lyapunov functional, and sufficient conditions are gained to ensure the resulting dynamic is stochastically stable. In the sequel, the asynchronous controller parameters are further achieved to reflect the discrepancy between fading channel mode and its detected one. Finally, an application-oriented example is rendered to confirm the effectiveness and applicability of the developed control strategy. © 2021 Elsevier B.V. Ha, M., Wang, D., Liu, D. Generalized value iteration for discounted optimal control with stability analysis (2021) 147, art. no. 104847, . Cited 23 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097337175&doi=10.1016%2fj.sysconle.2020.104847&partnerID=40&md5=e67ae0fd39ba4233bb3368ee41c71ce2 DOI: 10.1016/j.sysconle.2020.104847 AFFILIATIONS: School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Faculty of Information Technology, Beijing University of Technology, Beijing, 100124, China; Beijing Key Laboratory of Computational Intelligence and Intelligent System, Beijing University of Technology, Beijing, 100124, China; Department of Electrical and Computer Engineering, University of Illinois at Chicago, Chicago, IL 60607, United States ABSTRACT: In this work, the generalized value iteration with a discount factor is developed for optimal control of discrete-time nonlinear systems, which is initialized with a positive definite value function rather than zero. The convergence analysis of the discounted value function sequence is provided. The condition for the discount factor is given to guarantee the stability of the controlled plants. With this operation, the iterative control policy that asymptotically stabilizes the closed-loop system can be determined. The introduction of a discount factor has eased some conditions that the system dynamics and the initialization of the generalized value iteration need to fulfill. It is not required that the initial control policy is stabilizing. In the iteration process, under some conditions, if the system is asymptotically stable at the current iteration, then it can be guaranteed that the iterative control policies after this current iteration step also are stabilizing. It is convenient and practical to evaluate the asymptotic stability of the closed-loop system using the iterative control policy. A numerical example with physical background is carried out to validate the present results. © 2020 Elsevier B.V. Chen, J., Tepljakov, A., Petlenkov, E., Chen, Y., Zhuang, B. Boundary Mittag-Leffler stabilization of coupled time fractional order reaction–advection–diffusion systems with non-constant coefficients (2021) 149, art. no. 104875, . Cited 17 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099802375&doi=10.1016%2fj.sysconle.2021.104875&partnerID=40&md5=d2f1e18e74eb4f352835f9be0bd1914f DOI: 10.1016/j.sysconle.2021.104875 AFFILIATIONS: Aliyun School of Big Data, Changzhou University, Changzhou, Jiangsu, 213164, China; Department of Computer Systems, Tallinn University of Technology, Tallinn, 19086, Estonia; Mechatronics, Embedded Systems and Automation Lab, University of California, Merced, CA 95343, United States; School of Information Engineering, Binzhou University, Binzhou, Shandong, 256600, China ABSTRACT: This paper is concerned with boundary control for a class of coupled time fractional order reaction–advection–diffusion (FRAD) systems with non-constant coefficients (space-dependent coefficients) by state feedback. Partial differential equation (PDE) backstepping makes available to stabilize coupled time FRAD systems modeled by fractional PDEs. With boundary controller design and discussion on well-posedness of control kernel equations, the Mittag-Leffler stability of the closed-loop system is analyzed theoretically by the fractional Lyapunov method. A numerical scheme is constructed for coupled FRAD system to simulate numerical examples when the kernel equations have not the explicit solution. Comments on robustness to perturbation parameters in system coefficients are finally stated. © 2021 Elsevier B.V. Fang, W., Zamani, M., Chen, Z. Secure and privacy preserving consensus for second-order systems based on Paillier encryption (2021) 148, art. no. 104869, . Cited 17 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099485830&doi=10.1016%2fj.sysconle.2020.104869&partnerID=40&md5=c374dd67004323806df5488c867565fc DOI: 10.1016/j.sysconle.2020.104869 AFFILIATIONS: School of Electrical Engineering and Computing, The University of Newcastle, Callaghan, NSW 2308, Australia; Department of Medical Physics and Engineering, Shiraz University of Medical Sciences, Shiraz, Iran ABSTRACT: This paper aims at secure and privacy-preserving consensus algorithms of networked systems. Due to the technical challenges behind decentralized design of such algorithms, the existing results are mainly restricted to a network of systems with simplest first-order dynamics. Like many other control problems, breakthrough of the gap between first-order dynamics and higher-order ones demands for more advanced technical developments. In this paper, we explore a Paillier encryption based average consensus algorithm for a network of systems with second-order dynamics, with randomness added to network weights. The conditions for privacy-preserving, especially depending on consensus rate, are thoroughly studied with theoretical analysis and numerical verification. © 2020 Elsevier B.V. Chen, G., Fan, C., Lam, J., Sun, J., Xia, J. Aperiodic sampled-data controller design for switched Itô stochastic Markovian jump systems (2021) 157, art. no. 105031, . Cited 12 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115777852&doi=10.1016%2fj.sysconle.2021.105031&partnerID=40&md5=64359b941083292fb8003c23b47b1f8b DOI: 10.1016/j.sysconle.2021.105031 AFFILIATIONS: School of Mathematics Science, Liaocheng University, Liaocheng, Shandong, China; School of Automation, Beijing Institute of Technology, Beijing, China; Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong; Key Laboratory of Intelligent Control and Decision of Complex System, Beijing Institute of Technology, Beijing, China; Beijing Institute of Technology Chongqing Innovation Center, Chongqing, China ABSTRACT: In this paper, aperiodic sampled-data control for a class of Itô stochastic Markovian jump systems with switching transition rate matrix containing partially known elements is investigated. By introducing a loop-based Lyapunov functional, mean square exponential stability criteria are presented and mode-dependent aperiodic sampled-data controllers are designed. Due to the constraint on the upper bound of the sampling interval is no greater than the dwell time, the transition rate matrix may switch in a sampling interval. The issue concerning the asynchronization between the sampled-data controller mode and the system mode is hence considered. A practical RLC electrical circuit example is presented to illustrate the effectiveness of the method. © 2021 Elsevier B.V. Bisoffi, A., De Persis, C., Tesi, P. Trade-offs in learning controllers from noisy data (2021) 154, art. no. 104985, . Cited 12 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109578107&doi=10.1016%2fj.sysconle.2021.104985&partnerID=40&md5=d9b4fb8b8374949191bfa00c6f8f75d4 DOI: 10.1016/j.sysconle.2021.104985 AFFILIATIONS: ENTEG and the J.C. Willems Center for Systems and Control, University of Groningen, Groningen, 9747 AG, Netherlands; DINFO, University of Florence, Florence, 50139, Italy ABSTRACT: In data-driven control, a central question is how to handle noisy data. In this work, we consider the problem of designing a stabilizing controller for an unknown linear system using only a finite set of noisy data collected from the system. For this problem, many recent works have considered a disturbance model based on energy-type bounds. Here, we consider an alternative more natural model where the disturbance obeys instantaneous bounds. In this case, the existing approaches, which would convert instantaneous bounds into energy-type bounds, can be overly conservative. In contrast, without any conversion step, simple arguments based on the S-procedure lead to a very effective controller design through a convex program. Specifically, the feasible set of the latter design problem is always larger, and the set of system matrices consistent with data is always smaller and decreases significantly with the number of data points. These findings and some computational aspects are examined in a number of numerical examples. © 2021 The Author(s) Liu, Y., Li, H. Logical matrix factorization towards topological structure and stability of probabilistic Boolean networks (2021) 149, art. no. 104878, . Cited 11 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099612813&doi=10.1016%2fj.sysconle.2021.104878&partnerID=40&md5=6aadfee8f3f3a45d2f60f00ba19faa78 DOI: 10.1016/j.sysconle.2021.104878 AFFILIATIONS: School of Mathematics and Statistics, Shandong Normal University, Jinan, 250014, China ABSTRACT: The study of logical matrix factorization provides a new insight into the matrix dimension reduction problems of biological systems. This paper develops the logical matrix factorization technique for exploring the topological structure and stability of probabilistic Boolean networks (PBNs). Firstly, the union set of distinct indices in factorized structural matrices for different modes is obtained, based on which, a size-reduced system is constructed for the original PBN. Secondly, it is proved that the topological structure of original PBN is equivalent to that of the size-reduced system. Thirdly, the equivalence of finite-time stability and stability in distribution between the original PBN and the size-reduced system is further revealed. Finally, the effectiveness of the obtained new results are verified via several Boolean models of genetic regulatory networks (GRNs). © 2021 Elsevier B.V. Wang, B., Ashrafiuon, H., Nersesov, S. Leader–follower formation stabilization and tracking control for heterogeneous planar underactuated vehicle networks (2021) 156, art. no. 105008, . Cited 10 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112274119&doi=10.1016%2fj.sysconle.2021.105008&partnerID=40&md5=798f525d61312d7e725dfa389ab69645 DOI: 10.1016/j.sysconle.2021.105008 AFFILIATIONS: Department of Mechanical Engineering, Villanova University, Villanova, PA 19085, United States ABSTRACT: In this paper, we solve the distributed leader–follower simultaneous formation stabilization and tracking control problem for heterogeneous planar underactuated vehicle networks without global position measurements of the followers. The vehicles in the network are modeled as generic 3-DOF planar rigid bodies with two control inputs, and are allowed to have identical or non-identical dynamics. By incorporating graph theory, passivity-based control, partial stability theory, Matrosov's theorem and the persistence of excitation concept, a smooth formation control scheme is proposed to simultaneously address the formation stabilization and formation tracking problems without switching. Moreover, the structure of the controller is relatively simple compared to the existing controllers in the literature, and thus, is practical and easy to implement. Simulations on a group of underactuated vehicles including nonholonomic mobile robots and surface vessels are presented to demonstrate the effectiveness of the proposed control scheme. © 2021 Elsevier B.V. Liu, H., Wang, Y., Xi, J. Completely distributed formation control for networked quadrotors under switching communication topologies (2021) 147, art. no. 104841, . Cited 10 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097064002&doi=10.1016%2fj.sysconle.2020.104841&partnerID=40&md5=63720fb1a91720ee561bd1294c527f40 DOI: 10.1016/j.sysconle.2020.104841 AFFILIATIONS: School of Astronautics, Beihang University, Beijing, 100191, China; Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies of Ministry of Education, Beihang University, Beijing, 100191, China; High-Tech Institute of Xi'an, Xi'an, 710025, China ABSTRACT: This paper investigates a completely distributed adaptive formation control protocol for networked quadrotors under switching communication topologies, where the dynamics of each quadrotor involves seriously nonlinearity and uncertainty simultaneously. For the switching communication topologies case, the adaptive formation control protocol is proposed to guarantee that the translational and rotational tracking errors of the global closed-loop system can converge into a priori set neighborhood of the origin ultimately. Furthermore, the proposed formation control protocol is completely distributed, which means that the controller of each quadrotor only needs the information from itself and its neighbors. Numerical simulation results on the quadrotor team are provided to confirm the effectiveness and advantages of the proposed adaptive formation control protocol. © 2020 Elsevier B.V. Bonassi, F., Farina, M., Scattolini, R. On the stability properties of Gated Recurrent Units neural networks (2021) 157, art. no. 105049, . Cited 9 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116578643&doi=10.1016%2fj.sysconle.2021.105049&partnerID=40&md5=c2c09f7443dfb4646ddc7cdc7a5775a7 DOI: 10.1016/j.sysconle.2021.105049 AFFILIATIONS: Dipartimento di Elettronica, Informatica e Bioingegneria, Politecnico di Milano, Milano, 20133, Italy ABSTRACT: The goal of this paper is to provide sufficient conditions for guaranteeing the Input-to-State Stability (ISS) and the Incremental Input-to-State Stability (δISS) of Gated Recurrent Units (GRUs) neural networks. These conditions, devised for both single-layer and multi-layer architectures, consist of nonlinear inequalities on network's weights. They can be employed to check the stability of trained networks, or can be enforced as constraints during the training procedure of a GRU. The resulting training procedure is tested on a Quadruple Tank nonlinear benchmark system, showing remarkable modeling performances. © 2021 Elsevier B.V. Rocha, K.D.T., Terra, M.H. Robust Kalman filter for systems subject to parametric uncertainties (2021) 157, art. no. 105034, . Cited 9 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116046567&doi=10.1016%2fj.sysconle.2021.105034&partnerID=40&md5=fb49582978549e8bd4e9c8985646ee5b DOI: 10.1016/j.sysconle.2021.105034 AFFILIATIONS: Department of Electrical and Computer Engineering, São Carlos School of Engineering, University of São Paulo, Av. Trabalhador São Carlense, 400, São Carlos-SP, 13566-590, Brazil ABSTRACT: State estimation plays a fundamental role in control systems that rely on the knowledge of the underlying system state, especially when it is not readily available. The Kalman filter is among the most popular techniques in this matter. Nonetheless, one of its well-known shortcomings is the assumption that an exact system model is available. The difficulty in fulfilling this premise justifies the demand for estimation strategies that limit the effect of model uncertainties. In this paper, we propose a robust Kalman filter for uncertain linear discrete-time systems. We assume a general setting in which all matrices of both the system and measurement models are subject to norm-bounded parametric uncertainties. By adopting a purely deterministic viewpoint and applying the penalty function method, we formulate a robust regularized least-squares estimation problem. We further analyze how the penalty parameter influences the estimation performance. The resulting filter is presented both in a symmetric matrix arrangement and as explicit algebraic expressions in a Kalman-like structure that is suitable for online applications. Under reasonable conditions, we show that the steady-state filter is stable and, for quadratically stable systems, guarantees a bounded error variance. With a numerical example, we evaluate the proposed filter and compare its performance with other robust filtering approaches. © 2021 Elsevier B.V. Liu, P., Xiao, F., Wei, B., Wang, A. Distributed constrained optimization problem of heterogeneous linear multi-agent systems with communication delays (2021) 155, art. no. 105002, . Cited 9 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111667278&doi=10.1016%2fj.sysconle.2021.105002&partnerID=40&md5=21e3b4156ba0938b7173df6db07c5d62 DOI: 10.1016/j.sysconle.2021.105002 AFFILIATIONS: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206, China; School of Control and Computer Engineering, North China Electric Power University, Beijing, 102206, China; School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China ABSTRACT: This paper addresses the constrained distributed optimization problem of heterogeneous linear multi-agent systems, where the agents with linear dynamics are subject to local set constraints, global nonlinear inequality constraints and heterogeneous communication delays. Agents collaborate to minimize a global objective function by communicating with their neighbors in a graph. Each agent's decision variable is constrained in a local set. The decision variables of all agents are coupled by global inequality constraints which are modeled by nonlinear functions. To handle the heterogeneous constant communication delays, the scattering transformation between neighbors is employed. We design a new distributed control law to investigate the passivity of systems of individual agents in the presence of constraints and communication delays. Integrating the proposed control law with the scattering transformation, we prove that systems converge to the optimal solution which minimizes the global objective functions. Simulations of heterogeneous linear multi-agent systems are presented to illustrate the effectiveness of the distributed control law. © 2021 Elsevier B.V. Li, X., Liu, W., Mao, X., Zhao, J. Stabilization and destabilization of hybrid systems by periodic stochastic controls (2021) 152, art. no. 104929, . Cited 9 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104376571&doi=10.1016%2fj.sysconle.2021.104929&partnerID=40&md5=0bb75b684fd776f1d0baf20881c91958 DOI: 10.1016/j.sysconle.2021.104929 AFFILIATIONS: School of Mathematics and Statistics, Northeast Normal University, Changchun, 130024, China; Department of Mathematics, Shanghai Normal University, Shanghai, 200234, China; Department of Mathematics and Statistics, University of Strathclyde, Glasgow, G1 1XH, United Kingdom; School of Mathematical Science, Liaocheng University, Liaocheng, 252059, China ABSTRACT: This paper aims to determine whether or not a periodic stochastic feedback control can stabilize or destabilize a given nonlinear hybrid system. New methods are developed and sufficient conditions on the stability and instability for hybrid nonlinear systems with periodic stochastic perturbations are provided. These results are then used to examine stabilization and destabilization by periodic stochastic feedback controls, including intermittent stochastic controls. © 2021 Elsevier B.V. Liu, C., Liu, Y. Finite-time stabilization with arbitrarily prescribed settling-time for uncertain nonlinear systems (2022) 159, art. no. 105088, . Cited 8 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122542799&doi=10.1016%2fj.sysconle.2021.105088&partnerID=40&md5=da68b257a95942ae7512e5d5ddc9484e DOI: 10.1016/j.sysconle.2021.105088 AFFILIATIONS: School of Control Science and Engineering, Shandong University, Jinan, 250061, China ABSTRACT: This paper considers global finite-time stabilization with arbitrarily prescribed settling-time for nonlinear systems with unknown control directions and other serious uncertainties. In view of the challenge of the problem and the scarcity of available methods, several motivating facts are offered by elaborating examples and counterexamples. The facts disclose the potential obstructions in pursuing continuous controllers and force us to resort to powerful discontinuous feedbacks. By combining the method of adding a power integrator, homogeneous approach and desingularization technique, a state-feedback controller with design parameters is first proposed. Then a switching logic is proposed to tune the parameters online, wherein two types of switching sequences are involved to suppress serious uncertainties and to guarantee arbitrarily prescribed settling-time, respectively. Also, fixed-time stabilization is considered as a special case, aiming at the trade-off between arbitrary rapidness and high control cost. Two examples are provided to demonstrate the effectiveness of the proposed strategy. © 2021 Elsevier B.V. Zhai, L., Vamvoudakis, K.G. Data-based and secure switched cyber–physical systems (2021) 148, art. no. 104826, . Cited 8 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099233055&doi=10.1016%2fj.sysconle.2020.104826&partnerID=40&md5=c9566e7f46ab0d263123eca8025257ee DOI: 10.1016/j.sysconle.2020.104826 AFFILIATIONS: Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States ABSTRACT: In this paper, we develop a completely model-free moving target defense framework for the detection and mitigation of sensor and/or actuator attacks in cyber–physical systems with dynamics that evolve in discrete-time. We incorporate an intrusion detection mechanism based on an approximate dynamic programming technique that learns the policies for optimal regulation and optimal tracking while simultaneously defending against actuator and sensor attacks in a model-free fashion. Switching rules are leveraged to force proactive and reactive defense mechanisms as well as, guarantee the stability of the equilibrium point. Finally, as a case study, we apply the proposed moving target defense framework to a DC–DC converter that is used in electric vehicles. © 2020 Elsevier B.V. Aleksandrov, A. On the existence of a common Lyapunov function for a family of nonlinear positive systems (2021) 147, art. no. 104832, . Cited 8 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097187276&doi=10.1016%2fj.sysconle.2020.104832&partnerID=40&md5=f21e18d80806b1c93e9dcb24a6e4f4a6 DOI: 10.1016/j.sysconle.2020.104832 AFFILIATIONS: Saint Petersburg State University, 7-9 Universitetskaya nab., Saint Petersburg, 199034, Russian Federation ABSTRACT: This paper is devoted to the stability analysis of a class of switched nonlinear positive systems with nonlinearities of a sector type. A special construction of common Lyapunov function is proposed for the family of subsystems associated with a switched system and conditions of the existence of such a function are derived. The obtained results are used for the absolute stability investigation of switched systems with rank one difference. © 2020 Elsevier B.V. Tran, K.Q., Nguyen, D.H. Exponential stability of impulsive stochastic differential equations with Markovian switching (2022) 162, art. no. 105178, . Cited 7 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125466893&doi=10.1016%2fj.sysconle.2022.105178&partnerID=40&md5=3a47f6c92df10c964c4154d626028315 DOI: 10.1016/j.sysconle.2022.105178 AFFILIATIONS: Department of Applied Mathematics and Statistics, State University of New York, Korea Campus, 119-2 Songdo Moonhwa-ro, Incheon, Yeonsu-Gu, 21985, South Korea; Department of Mathematics, University of Alabama, Tuscaloosa, AL 35487, United States ABSTRACT: This paper is devoted to moment exponential stability of a class of Markovian switching stochastic differential equations with impulsive perturbations. Taking into consideration the long time behavior of the switching device, we derive explicit criteria for stability and instability. The contribution of the Markovian switching and impulsive perturbations to the stability and instability is revealed. © 2022 Elsevier B.V. Mazenc, F., Malisoff, M., Barbalata, C. Event-triggered control for continuous-time linear systems with a delay in the input (2022) 159, art. no. 105075, . Cited 7 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122138476&doi=10.1016%2fj.sysconle.2021.105075&partnerID=40&md5=be4100cad2a788f587fe1db77e17578f DOI: 10.1016/j.sysconle.2021.105075 AFFILIATIONS: Inria Saclay, L2S-CNRS-CentraleSupélec, 3 rue Joliot Curie, Gif-sur-Yvette, 91192, France; Department of Mathematics, Louisiana State University, Baton RougeLA 70803-4918, United States; Department of Mechanical and Industrial Engineering, Louisiana State University, Baton RougeLA 70803, United States ABSTRACT: We provide an event-triggered control technique for a family of linear time-varying continuous-time systems with a constant known pointwise delay in the input. We adopt a subpredictor based prediction technique, and we provide sufficient conditions that ensure that Zeno behavior does not occur. At each time, only delayed measurements are needed to implement the control. Also, the delay can be an arbitrarily large constant. We prove an input-to-state stability property for the closed-loop system, using the theory of cooperative systems. We apply our method to a gyroscopic control problem for a curve tracking dynamics arising in marine robotics. © 2021 Elsevier B.V. Ahmed, H.M. Conformable fractional stochastic differential equations with control function (2021) 158, art. no. 105062, . Cited 7 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118591274&doi=10.1016%2fj.sysconle.2021.105062&partnerID=40&md5=635ce3ad41c24de06e2a8375f674e14c DOI: 10.1016/j.sysconle.2021.105062 AFFILIATIONS: Higher Institute of Engineering, El-Shorouk Academy, El-Shorouk City, Cairo, Egypt ABSTRACT: In this work, we consider a class of conformable fractional stochastic differential equations driven by Rosenblatt process. By employing stochastic analysis, fractional calculus and fixed point theorem, we investigate the approximate controllability and null controllability results for the considered problems. Finally, two examples are introduced to explain the obtained results. © 2021 Elsevier B.V. Wen, Y., Lou, X., Wu, W., Cui, B. Impulsive adaptive observer design for a class of hybrid ODE–PDE cascade systems with uncertain parameters (2021) 154, art. no. 104969, . Cited 7 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108147266&doi=10.1016%2fj.sysconle.2021.104969&partnerID=40&md5=4ffe843ad0f2136140f7307584b3a11b DOI: 10.1016/j.sysconle.2021.104969 AFFILIATIONS: Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Jiangnan University, Wuxi, 214122, China ABSTRACT: In this paper, an impulsive adaptive observer is proposed for online estimates of a class of hybrid cascade systems with uncertain parameters. The hybrid cascade system is formed by an ordinary differential equation (ODE) coupled with a partial differential equation (PDE) with uncertain parameters. In the hybrid cascade system, the state of the connection point between the two subsystems cannot be directly available, which makes it difficult to obtain online estimates of the inaccessible states. To deal with the complex observation problem, an impulsive adaptive observer is designed using the backstepping approach and the extended Kalman observer. In addition, the convergence of the proposed observer is examined. The backstepping transformation plays a crucial role in the convergence proof. Finally, a numerical example is provided to illustrate the effectiveness of the proposed method. © 2021 Elsevier B.V. Astolfi, D., Zaccarian, L., Jungers, M. On the use of low-pass filters in high-gain observers (2021) 148, art. no. 104856, . Cited 7 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099174498&doi=10.1016%2fj.sysconle.2020.104856&partnerID=40&md5=a9d33a5c7c45156ba689bbb6f0eb63f5 DOI: 10.1016/j.sysconle.2020.104856 AFFILIATIONS: Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 boulevard du 11 novembre 1918, Villeurbanne, F-69100, France; LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France; Department of Industrial Engineering, University of Trento, Italy; Université de Lorraine, CNRS, CRAN, Nancy, F-54000, France ABSTRACT: To address the well-known noise sensitivity problems associated with high-gain observers, we insert a low-pass filter on the measurement channel. Considering nonlinear plants in observability canonical form, we first motivate an architecture where the output error is filtered by a linear system parametrized by its arbitrary order and a scalar positive gain. Our main result establishes an exponential finite gain bound for the estimation error, from the measurement noise, this gain being dependent on the high-gain and filter parameters. We also prove bounds depending on the filter parameters characterizing improved high-frequency gains from the measurement noise to the estimation error. The proposed construction is shown to behave desirably in numerical simulations. © 2020 Elsevier B.V. Sontag, E.D. Remarks on input to state stability of perturbed gradient flows, motivated by model-free feedback control learning (2022) 161, art. no. 105138, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123823555&doi=10.1016%2fj.sysconle.2022.105138&partnerID=40&md5=04cbb7223576b144dbd9a004ca36bc40 DOI: 10.1016/j.sysconle.2022.105138 AFFILIATIONS: Bioengineering and Electrical and Computer Engineering Departments, Northeastern University, Boston, MA, United States; Affiliate member of Mathematics and Chemical Engineering Departments, Northeastern University, Boston, MA, United States; Laboratory of Systems Pharmacology, Program in Therapeutic Science, Harvard Medical School, Boston, MA, United States ABSTRACT: Recent work on data-driven control and reinforcement learning has renewed interest in a relative old field in control theory: model-free optimal control approaches which work directly with a cost function and do not rely upon perfect knowledge of a system model. Instead, an “oracle” returns an estimate of the cost associated to, for example, a proposed linear feedback law to solve a linear–quadratic regulator problem. This estimate, and an estimate of the gradient of the cost, might be obtained by performing experiments on the physical system being controlled. This motivates in turn the analysis of steepest descent algorithms and their associated gradient differential equations. This note studies the effect of errors in the estimation of the gradient, framed in the language of input to state stability, where the input represents a perturbation from the true gradient. Since one needs to study systems evolving on proper open subsets of Euclidean space, a self-contained review of input to state stability definitions and theorems for systems that evolve on such sets is included. The results are then applied to the study of noisy gradient systems, as well as the associated steepest descent algorithms. © 2022 Elsevier B.V. Ovchinnikov, A., Pillay, A., Pogudin, G., Scanlon, T. Computing all identifiable functions of parameters for ODE models (2021) 157, art. no. 105030, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115888007&doi=10.1016%2fj.sysconle.2021.105030&partnerID=40&md5=e79817aa4b9295ad4b43011f1efe28d2 DOI: 10.1016/j.sysconle.2021.105030 AFFILIATIONS: CUNY Queens College, Department of Mathematics, 65-30 Kissena Blvd, Queens, NY 11367, United States; CUNY Graduate Center, Mathematics and Computer Science, 365 Fifth Avenue, New YorkNY 10016, United States; University of Notre Dame, Department of Mathematics, Notre Dame, IN 46556, United States; LIX, CNRS, École Polytechnique, Institute Polytechnique de Paris, 1 rue Honoré d'Estienne d'Orves, Palaiseau, 91120, France; University of California, Berkeley, Department of Mathematics, Evans Hall, Berkeley, CA 94720-3840, United States ABSTRACT: Parameter identifiability is a structural property of an ODE model for recovering the values of parameters from the data (i.e., from the input and output variables). This property is a prerequisite for meaningful parameter identification in practice. In the presence of nonidentifiability, it is important to find all functions of the parameters that are identifiable. The existing algorithms check whether a given function of parameters is identifiable or, under the solvability condition, find all identifiable functions. However, this solvability condition is not always satisfied, which presents a challenge. Our first main result is an algorithm that computes all identifiable functions without any additional assumptions, which is the first such algorithm as far as we know. Our second main result concerns the identifiability from multiple experiments (with generically different inputs and initial conditions among the experiments). For this problem, we prove that the set of functions identifiable from multiple experiments is what would actually be computed by input–output equation-based algorithms (whether or not the solvability condition is fulfilled), which was not known before. We give an algorithm that not only finds these functions but also provides an upper bound for the number of experiments to be performed to identify these functions. We provide an implementation of the presented algorithms. © 2021 The Authors Ngoc, P.H.A. On exponential stability in mean square of neutral stochastic functional differential equations (2021) 154, art. no. 104965, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108095626&doi=10.1016%2fj.sysconle.2021.104965&partnerID=40&md5=85e9d4cac9d6f703722ab4a85f2424fe DOI: 10.1016/j.sysconle.2021.104965 AFFILIATIONS: Department of Mathematics, Vietnam National University-HCMC, International University, Thu Duc city, Ho Chi Minh city, Viet Nam ABSTRACT: General neutral stochastic functional differential equations are considered. A novel approach to exponential stability of such equations is proposed. New criteria for the mean square exponential stability of neutral stochastic functional differential equations are given. A discussion and illustrative examples are presented. © 2021 Elsevier B.V. de Souza, C., Leite, V.J.S., Tarbouriech, S., Castelan, E.B. Event-triggered policy for dynamic output stabilization of discrete-time LPV systems under input constraints (2021) 153, art. no. 104950, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105288383&doi=10.1016%2fj.sysconle.2021.104950&partnerID=40&md5=d902b7c35c999d8cf94db96fa39685b9 DOI: 10.1016/j.sysconle.2021.104950 AFFILIATIONS: Department of Automation and Systems Engineering, DAS/CTC/UFSC, Florianópolis, SC 88040-900, Brazil; Department of Mechatronics Engineering, CEFET–MG, R. Álvares Azevedo, 400, Divinópolis, MG 35503-822, Brazil; LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France ABSTRACT: This paper concerns the event-triggered dynamic output-feedback control of discrete-time linear parameter-varying (LPV) systems subject to saturating actuators. Two independent event-triggering schemes are introduced to determine whether the current signals should be transmitted (a) from the sensor to the controller and (b) from the controller to the actuator. As a result, the communication resources can be significantly saved. Both the emulation-based problem and the co-design problem are addressed. Sufficient conditions based on linear matrix inequalities (LMIs) are derived to ensure the regional asymptotic stability of the origin for the closed-loop system. A convex optimization procedure is proposed to determine the controller matrices and the event-triggering parameters aiming at reducing the number of updates on the independent channels sensor-to-controller and controller-to-actuator. At last, numerical examples are employed to testify to the validity of the proposed methods. © 2021 Elsevier B.V. Jia, C., Longman, R.W. An adaptive smooth second-order sliding mode repetitive control method with application to a fast periodic stamping system (2021) 151, art. no. 104912, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103962394&doi=10.1016%2fj.sysconle.2021.104912&partnerID=40&md5=851fffab43c490353fc23e4037a25956 DOI: 10.1016/j.sysconle.2021.104912 AFFILIATIONS: School of Electrical and Electronic Engineering, Tianjin University of Technology, No. 391 Binshui West Avenue, Xiqing District, Tianjin, China; Department of Mechanical Engineering, Columbia University, 500 W. 120th street, New York, NY, United States ABSTRACT: This paper proposes an adaptive smooth second-order sliding mode repetitive control method for a class of non-linear systems with unknown disturbances and uncertainties. The key point is that the control law combines the advantages of adaptive second-order sliding mode control with the benefits of repetitive control. When both periodic and aperiodic disturbances exist in the system, the proposed method forces the sliding mode into a smaller pre-specified region in finite time, and when only periodic disturbance exists, the proposed method forces the sliding mode to converge to zero. Compared with pure sliding mode control, the proposed method is especially suitable for systems with sudden periodic load disturbances, for example from periodic impacts. Pure sliding mode control needs to adjust at each impact. Repetitive control knows each impact is coming and learns how to handle it, while sliding mode control can be dedicated to addressing aperiodic disturbances. This can result in smaller error levels. The stability of the proposed method is proved based on a Lyapunov approach. The performance is evaluated on a hydraulic press system via simulations. © 2021 Elsevier B.V. Meng, W., Shi, J. A global maximum principle for stochastic optimal control problems with delay and applications (2021) 150, art. no. 104909, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102968092&doi=10.1016%2fj.sysconle.2021.104909&partnerID=40&md5=4ba484b31d6c64cb2b738422ed5af00e DOI: 10.1016/j.sysconle.2021.104909 AFFILIATIONS: School of Mathematics, Shandong University, Jinan, 250100, China ABSTRACT: In this paper, an open problem is solved, for the stochastic optimal control problem with delay where the control domain is nonconvex and the diffusion term contains both control and its delayed term. Inspired by previous results about delayed stochastic control systems, Peng's global stochastic maximum principle is generalized to the time delayed case. A special backward stochastic differential equation is introduced to deal with the cross terms, when applying the duality technique. Comparing with the classical result, the maximum condition contains an indicator function, which in fact is the characteristic of the stochastic optimal control problem with delay. Furthermore, to illustrate the applications of our theoretical results, three dynamic optimization problems are addressed based on the global maximum principle. © 2021 Elsevier B.V. Pirani, M., Taylor, J.A., Sinopoli, B. Strategic sensor placement on graphs (2021) 148, art. no. 104855, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098972543&doi=10.1016%2fj.sysconle.2020.104855&partnerID=40&md5=40f2662b46e5940ec10c4f88682166b6 DOI: 10.1016/j.sysconle.2020.104855 AFFILIATIONS: Department of Electrical and Computer Engineering, University of Toronto, Canada; Department of Electrical and Systems Engineering, Washington University in St Louis, United States ABSTRACT: This paper studies optimal sensor placement in networked control systems for improving the detectability of cyber–physical attacks. The problem is formulated as a game between an attacker and a detector. The attacker's decision is to select a set of nodes in the network to attack, and the detector's decision is to places sensors on a set of nodes. The detector tries to maximize the detectability of attack signals. The attacker tries to maximize its impact while avoiding detection. We analyze the game using structured systems theory and other graph-theoretic concepts. The equilibrium strategy of the detector determines the optimal locations of the sensors. We study pure and mixed strategies for the case of single attacked–single detected nodes. We extend some of our results to the case of multiple attacked–multiple detected nodes. For the cases where the game does not admit a Nash equilibrium, we discuss the Stackelberg game and give graph-theoretic bounds on the game value. Finally, we discuss the Stackelberg equilibrium strategies for simple graph topologies. © 2020 Elsevier B.V. Coron, J.-M., Nguyen, H.-M. Null-controllability of linear hyperbolic systems in one dimensional space (2021) 148, art. no. 104851, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098939497&doi=10.1016%2fj.sysconle.2020.104851&partnerID=40&md5=3100210d4e68aa36bffe8fa6985a9b24 DOI: 10.1016/j.sysconle.2020.104851 AFFILIATIONS: Sorbonne Université, Université, Paris-Diderot SPC, CNRS, INRIA, Laboratoire Jacques-Louis Lions, équipe Cage, Paris, France; Department of Mathematics, EPFL SB CAMA, Station 8, Lausanne, CH-1015, Switzerland ABSTRACT: This paper is devoted to the controllability of a general linear hyperbolic system in one space dimension using boundary controls on one side. Under precise and generic assumptions on the boundary conditions on the other side, we previously established the optimal time for the null and the exact controllability for this system for a generic source term. In this work, we prove the null-controllability for any time greater than the optimal time and for any source term. Similar results for the exact controllability are also discussed. © 2020 Elsevier B.V. Lin, W., Sun, J. New results and examples in semiglobal asymptotic stabilization of nonaffine systems by sampled-data output feedback (2021) 148, art. no. 104850, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098058158&doi=10.1016%2fj.sysconle.2020.104850&partnerID=40&md5=a50f90da2bf5d770573fd7ef0776acac DOI: 10.1016/j.sysconle.2020.104850 AFFILIATIONS: Dongguan University of TechnologyGuangdong, China; Department of Electrical, Computer, and Systems Engineering, Case Western Reserve University, Cleveland, OH 44106, United States ABSTRACT: For a class of SISO non-affine systems, we address the problem of how semiglobal asymptotic stabilization (SGAS) can be achieved by n-dimensional sampled-data output feedback. The new result of this paper gives a partial answer to the open question in the recent work Lin (2020), where (2n−1)-dimensional output feedback controllers were designed based on the dynamic extension method. © 2020 Elsevier B.V. Tang, W., Daoutidis, P. Dissipativity learning control (DLC): Theoretical foundations of input–output data-driven model-free control (2021) 147, art. no. 104831, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097714872&doi=10.1016%2fj.sysconle.2020.104831&partnerID=40&md5=7353699191e654eb121f3577b6e2cb0b DOI: 10.1016/j.sysconle.2020.104831 AFFILIATIONS: Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, United States ABSTRACT: Data-driven, model-free control strategies leverage statistical or learning techniques to design controllers based on data instead of dynamic models. We have previously introduced the dissipativity learning control (DLC) method, where the dissipativity property is learned from the input–output trajectories of a system, based on which L2-optimal P/PI/PID controller synthesis is performed. In this work, we analyze the statistical conditions on dissipativity learning that enable control performance guarantees, and establish theoretical results on performance under nominal conditions as well as in the presence of statistical errors. The implementation of DLC is further formalized and is illustrated on a two-phase chemical reactor, along with a comparison to model identification-based LQG control. © 2020 Elsevier B.V. Gray, W.S., Ebrahimi-Fard, K. Generating series for networks of Chen–Fliess series (2021) 147, art. no. 104827, . Cited 6 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096680485&doi=10.1016%2fj.sysconle.2020.104827&partnerID=40&md5=217f1841263c876d803526adda479c3a DOI: 10.1016/j.sysconle.2020.104827 AFFILIATIONS: Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529, United States; Department of Mathematical Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, 7491, Norway ABSTRACT: Consider a set of single-input, single-output nonlinear systems whose input–output maps are described only in terms of convergent Chen–Fliess series without any assumption that finite dimensional state space models are available. It is shown that any additive or multiplicative interconnection of such systems always has a Chen–Fliess series representation that can be computed explicitly in terms of iterated formal Lie derivatives. © 2020 Elsevier B.V. Long, L., Wang, J. Safety-critical dynamic event-triggered control of nonlinear systems (2022) 162, art. no. 105176, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125601189&doi=10.1016%2fj.sysconle.2022.105176&partnerID=40&md5=fa0118497b6f120264d93dd30b3a409a DOI: 10.1016/j.sysconle.2022.105176 AFFILIATIONS: College of Information Science and Engineering, Northeastern University, Shenyang, 110819, China; State Key Laboratory of Synthetical Automation for Process Industries, Northeastern University, Shenyang, 110819, China ABSTRACT: This paper is concerned with the problem of safety-critical dynamic event-triggered control (ETC) for nonlinear systems. A novel safety-critical dynamic ETC strategy is proposed to simultaneously guarantee event-triggered safety and stability based on the union of input-to-state safe barrier function (ISSf-BF) and input-to-state stable Lyapunov function (ISS-LF). Also, an appropriate dynamic event-triggered mechanism (DETM) is constructed, and Zeno phenomenon of ETC in the safety-critical control framework is definitely excluded based on the DETM constructed. Compared with the existing safety-critical control designed in the framework of continuous-time feedback control, the proposed strategy constructs safety-critical event-triggered controller and an DETM, which greatly alleviates the unnecessary waste of communication and computation resources. Finally, three examples are presented to demonstrate the effectiveness of the proposed design strategy. © 2022 Elsevier B.V. Korotina, M., Romero, J.G., Aranovskiy, S., Bobtsov, A., Ortega, R. A new on-line exponential parameter estimator without persistent excitation (2022) 159, art. no. 105079, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119655071&doi=10.1016%2fj.sysconle.2021.105079&partnerID=40&md5=f6caf21efa67e5211208de179e053b58 DOI: 10.1016/j.sysconle.2021.105079 AFFILIATIONS: IETR – CentaleSupélec, Avenue de la Boulaie, Cesson-Sévigné, 35576, France; Faculty of Control Systems and Robotics, ITMO University, Saint-Petersburg, 197101, Russian Federation; Departamento Académico de Sistemas Digitales, ITAM, Río hondo 1Progreso Tizapán, Mexico City, 01080, Mexico ABSTRACT: In this paper we propose a new algorithm that estimates on-line the parameters of a classical vector linear regression equation Y=Ωθ, where Y∈Rn,Ω∈Rn×q are bounded, measurable signals and θ∈Rq is a constant vector of unknown parameters, even when the regressor Ω is not persistently exciting. Moreover, the convergence of the new parameter estimator is global and exponential and is given for both, continuous-time and discrete-time implementations. As an illustration example we consider the problem of parameter estimation of a linear time-invariant system, when the input signal is not sufficiently exciting, which is known to be a necessary and sufficient condition for the solution of the problem with standard gradient or least-squares adaptation algorithms. © 2021 Elsevier B.V. Guerrero, J.C., Chávez-Fuentes, J.R., Casavilca, J.E., Costa, E.F. Stability analysis of discrete-time Markov jump linear singular systems with partially known transition probabilities (2021) 158, art. no. 105057, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118595851&doi=10.1016%2fj.sysconle.2021.105057&partnerID=40&md5=28b61b354694c3e97684556e05aa6957 DOI: 10.1016/j.sysconle.2021.105057 AFFILIATIONS: Department of Sciences, Pontificia Universidad Católica del Perú, Peru; Instituto de Ciências Matemáticas e de Computação, Universidade de São Paulo at São Carlos, Brazil ABSTRACT: In this paper, we present sufficient conditions for the stochastic stability (SS) of a Markov jump linear singular system (MJLSS) with partially known transition probabilities. To handle this problem, we give two different approaches: the first one is based on the Dynamics decomposition (DD) of the system and the second one on the Weierstrass decomposition (WD). We show the relationship between these two approaches and provide a numerical example. By using the MATLAB Econometrics Toolbox, a simulation is run in order to validate our results. © 2021 Elsevier B.V. Zhao, W., Liu, H., Wan, Y. Data-driven fault-tolerant formation control for nonlinear quadrotors under multiple simultaneous actuator faults (2021) 158, art. no. 105063, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118357353&doi=10.1016%2fj.sysconle.2021.105063&partnerID=40&md5=e27bec02583eda0941ba4846d7992e37 DOI: 10.1016/j.sysconle.2021.105063 AFFILIATIONS: School of Astronautics, Beihang University, Beijing, 100191, China; Institute of Artificial Intelligence, Beihang University, Beijing, 100191, China; University of Texas at Arlington Research Institute, University of Texas at Arlington, Fort Worth, Texas, 76118, United States ABSTRACT: This paper addresses the problem of data-driven fault-tolerant formation control for quadrotors with nonlinearities, unknown system parameters, and multiple actuator faults in the vehicle dynamics. A distributed fault-tolerant formation control law is developed including a distributed observer to generate the position reference for each vehicle, a fault-tolerant position control law to track the position reference, and a fault-tolerant attitude control law to regulate the attitude. Reinforcement learning approaches are implemented to update the optimal control weights in the fault-tolerant formation control law design. Stability of the proposed fault-tolerant formation control law is proven and simulation results of quadrotors under multiple actuator faults are provided to demonstrate the effectiveness of the proposed method. © 2021 Elsevier B.V. Carè, A., Campi, M.C., Csáji, B.C., Weyer, E. Facing undermodelling in Sign-Perturbed-Sums system identification (2021) 153, art. no. 104936, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85110283373&doi=10.1016%2fj.sysconle.2021.104936&partnerID=40&md5=b01c4b93eafff73787e1d8624cb330e2 DOI: 10.1016/j.sysconle.2021.104936 AFFILIATIONS: University of Brescia, Brescia, Italy; SZTAKI: Institute for Computer Science and Control, Budapest, Hungary; The University of Melbourne, Melbourne, Australia ABSTRACT: Sign-Perturbed Sums (SPS) is a finite sample system identification method that constructs exact, non-asymptotic confidence regions for the unknown parameters of linear systems without using any knowledge about the disturbances except that they are symmetrically distributed. In the available literature, the theoretical properties of SPS have been investigated under the assumption that the order of the system model is known to the user. In this paper, we analyse the behaviour of SPS when the model assumed by the user does not match the data generation mechanism, and we propose a new SPS algorithm able to detect the circumstance that the model order is incorrect. © 2021 Elsevier B.V. Bhogaraju, I., Farasat, M., Malisoff, M., Krstic, M. Sequential predictors for delay-compensating feedback stabilization of bilinear systems with uncertainties (2021) 152, art. no. 104933, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107640874&doi=10.1016%2fj.sysconle.2021.104933&partnerID=40&md5=05c61a3d920b0ebd369ce05893a239a1 DOI: 10.1016/j.sysconle.2021.104933 AFFILIATIONS: Division of Electrical and Computer Engineering, Louisiana State University, Baton Rouge, LA 70803, United States; Department of Mathematics, Louisiana State University, Baton Rouge, LA 70803-4918, United States; Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093-0411, United States ABSTRACT: We construct delay-compensating input-to-state stabilizing feedback controllers for a class of nonlinear control systems that include bilinear systems that have pointwise delays in their inputs. Our new approach for delay compensation does not require constructing or estimating distributed terms in the formulas for the stabilizing control laws. We allow arbitrarily long constant input delays. We illustrate our findings in a power system example. © 2021 Elsevier B.V. Albertini, F., D'Alessandro, D. Subspace controllability of multi-partite spin networks (2021) 151, art. no. 104913, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103791162&doi=10.1016%2fj.sysconle.2021.104913&partnerID=40&md5=03a100ea0412fe5d74f9ad5c8f604a12 DOI: 10.1016/j.sysconle.2021.104913 AFFILIATIONS: Dipartimento di Tecnica e Gestione del Sistemi Industriali, Universita’ di Padova, Vicenza, Italy; Department of Mathematics, Iowa State University, United States ABSTRACT: In a network of spin [Formula presented] particles, controlled through an external electro-magnetic field, the gyromagnetic ratio of each spin is a parameter that characterizes the interaction of the spin with the external control field. Multipartite networks are such that the spins are divided into subsets according to their gyromagnetic ratio and spins in one set interact in the same way with all spins in another set. Due to the presence of symmetries in these types of systems, the underlying Hilbert state space splits into invariant subspaces for the dynamics. Subspace controllability is verified if every unitary evolution can be generated by the dynamics on these subspaces. We give an exact characterization, in terms of graph theoretic conditions, of subspace controllability for multipartite quantum spin networks. This extends and unifies previous results. © 2021 Elsevier B.V. Mazenc, F., Malisoff, M., Jiang, Z.-P. Reduced-order fast converging observers for systems with discrete measurements and measurement error (2021) 150, art. no. 104892, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101514595&doi=10.1016%2fj.sysconle.2021.104892&partnerID=40&md5=f807b9280cfc1abb5d87541ad50065d6 DOI: 10.1016/j.sysconle.2021.104892 AFFILIATIONS: Inria EPI DISCO, L2S-CNRS-CentraleSupélec, 3 rue Joliot Curie, Gif-sur-Yvette, 91192, France; Department of Mathematics, Louisiana State University, Baton RougeLA 70803-4918, United States; Department of Electrical and Computer Engineering, Tandon School of Engineering, New York University, Brooklyn, NY 11201, United States ABSTRACT: We provide novel reduced-order observer designs for continuous-time nonlinear systems with measurement error. Our first result applies to systems with continuous output measurements, and provides observers that converge in a fixed finite time that is independent of the initial state when the measurement error is zero. Our second result applies under discrete measurements, and provides observers that converge asymptotically with a rate of convergence that is proportional to the negative of the logarithm of the size of a sampling interval. Our observers satisfy an enhanced input-to-state stability property with respect to the measurement error, in which an overshoot term only depends on a recent history of the measurement error. We illustrate our observers using a model of a single-link robotic manipulator coupled to a DC motor with a nonrigid joint, and in a pendulum example. © 2021 Elsevier B.V. Bansal, H., Schulze, P., Abbasi, M.H., Zwart, H., Iapichino, L., Schilders, W.H.A., van de Wouw, N. Port-Hamiltonian formulation of two-phase flow models (2021) 149, art. no. 104881, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100893050&doi=10.1016%2fj.sysconle.2021.104881&partnerID=40&md5=5ca1edd04cafae3a56db2710cf148207 DOI: 10.1016/j.sysconle.2021.104881 AFFILIATIONS: Department of Mathematics and Computer Science, Eindhoven University of Technology, Netherlands; Institut für Mathematik, Technische Universität Berlin, Germany; Department of Applied Mathematics, University of Twente, Netherlands; Department of Mechanical Engineering, Eindhoven University of Technology, Netherlands; Department of Civil, Environmental and Geo-Engineering, University of Minnesota, United States ABSTRACT: Two-phase flows are frequently modelled and simulated using the Two-Fluid Model (TFM) and the Drift Flux Model (DFM). This paper proposes Stokes–Dirac structures with respect to which port-Hamiltonian representations for such two-phase flow models can be obtained. We introduce a non-quadratic candidate Hamiltonian function and present dissipative Hamiltonian representations for both models. We then use the structure of the corresponding formally skew-adjoint operator to derive a Stokes–Dirac structure for the two variants of multi-phase flow models. Moreover, we discuss the difficulties in deriving a port-Hamiltonian formulation of the DFM with general slip conditions, and argue why this model may not be energy-consistent. © 2021 The Author(s) Wang, S., Shu, Z., Chen, T. Event-triggered attitude synchronization of multiple rigid-body systems (2021) 149, art. no. 104879, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100689257&doi=10.1016%2fj.sysconle.2021.104879&partnerID=40&md5=966c9cb54cc8c24c4545eeb06283b466 DOI: 10.1016/j.sysconle.2021.104879 AFFILIATIONS: Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada ABSTRACT: In this paper, an attitude synchronization problem of multiple rigid-body systems is investigated by using an event-based approach. The leader and followers are described by unit quaternions. A nonlinear distributed observer with event-triggered observations is proposed to estimate the attitude and angular velocity of the leader without continuous information exchange. The triggering mechanism is intermittent and asynchronous; and a positive lower bound of inter-event triggering times is given to show that Zeno behavior can be excluded in the intermittent communication sequence for any agent. Based on the estimated attitude and angular velocity of the leader, a distributed controller is synthesized for each follower to achieve attitude synchronization with the leader via intermittent communication. Finally, an example is provided to illustrate the effectiveness of the theoretical results. © 2021 Elsevier B.V. Ma, J., Zheng, Y., Zhou, L. Game-based coalescence in multi-agent systems (2021) 148, art. no. 104853, . Cited 5 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098164092&doi=10.1016%2fj.sysconle.2020.104853&partnerID=40&md5=5f8f2874607a7e0fbda304b57f956a95 DOI: 10.1016/j.sysconle.2020.104853 AFFILIATIONS: School of Mathematics and Statistics, Ningxia University, Yinchuan, 750021, China; Shaanxi Key Laboratory of Space Solar Power Station System, School of Mechano-electronic Engineering, Xidian University, Xi'an 710071, China ABSTRACT: Agents are normally designed to be self-interested and tend to maximize their own interests in many realistic systems, such as robotics, smart grids and autonomous vehicles. In this paper, we propose a model of repeated bimatrix game to study the ubiquitous group behavior, coalescence, in multi-agent systems, where different agents form a union and keep consensus in states. We find that whether the system can reach coalescence will significantly depend on the payoffs, the functions of the distance between agents’ states. As a result, if the maximum initial distance of agents’ states is sufficiently large, all agents in the population will fail to reach coalescence. If the maximum initial distance remains sufficiently small, on the contrary, all agents will form a union. Moreover, the distribution and the expected value of coalescence time are explicitly obtained when the utility of agents is described by a power function. Finally, simulation examples are provided to validate the effectiveness of the theoretical results. © 2020 Elsevier B.V. Xu, H., Zhu, Q. New criteria on pth moment exponential stability of stochastic delayed differential systems subject to average-delay impulses (2022) 164, art. no. 105234, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129441792&doi=10.1016%2fj.sysconle.2022.105234&partnerID=40&md5=7a8b32ba486b5028ff8ae9c4a76433ab DOI: 10.1016/j.sysconle.2022.105234 AFFILIATIONS: MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Hunan, Changsha, 410081, China; Key Laboratory of Control and Optimization of Complex Systems, College of Hunan Province, Hunan Normal University, Changsha, 410081, China ABSTRACT: This note develops new stability criteria for stochastic delayed differential systems with average-delay impulses by using Razumikhin approach, stochastic analysis technique, average impulsive delay (AID) condition and average dwell time. Our results show that delayed system with destabilizing delay-dependent impulses is pth moment exponentially stable, where delays in impulses can be flexible enough compared with some recent works. The feature of the criteria is that the Razumikhin function is allowed to be a time-varying and sign-changing function, which looses some restrictions of the existing results. Furthermore, a numerical example is performed to account for the effectiveness and the correctness of our theory. © 2022 Elsevier B.V. Liu, Y., Wang, L., Yang, Y., Wu, Z.-G. Minimal observability of Boolean control networks (2022) 163, art. no. 105204, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127364713&doi=10.1016%2fj.sysconle.2022.105204&partnerID=40&md5=b72a4c5a2d79a0662afb74c784f5418b DOI: 10.1016/j.sysconle.2022.105204 AFFILIATIONS: College of Mathematics and Computer Science, Zhejiang Normal University, Jinhua, 321004, China; College of Mathematical Medicine, Zhejiang Normal University, Jinhua, 321004, China; Key Laboratory of Intelligent Education Technology and Application of Zhejiang Province, Zhejiang Normal University, Jinhua, 321004, China; State Key Laboratory of Industrial Control Technology, Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, 310027, China ABSTRACT: In this paper, the minimum observability of Boolean control networks (BCNs) is investigated. An augmented system is proposed to analyze the dynamical trajectories of state pairs, followed by an effective criterion for observability of BCNs utilizing graphic tools. A minimal observability problem is formulated based on the fact that observability of the underlying network is facilitated by injecting new measurements. By introducing an indicator matrix, the solution of added measurements in vector form can be converted into dealing with the equations, by which, all the feasible measurements can be derived. Furthermore, the solution of the least added measurements can be solved by a minimum set covering problem. Meanwhile, two examples are given to illustrate the theoretical results. © 2022 Elsevier B.V. Liu, X., Lin, W., Zhao, C., Hu, Y. Digital control of a family of time-delay feedforward systems with sparse sampling (2022) 163, art. no. 105200, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127335099&doi=10.1016%2fj.sysconle.2022.105200&partnerID=40&md5=dc18a24e3c993082f725a5a8daf60cbe DOI: 10.1016/j.sysconle.2022.105200 AFFILIATIONS: School of Electronic Engineering, Dongguan University of Technology, Guangdong Province, Dongguan, 523808, China; Department of Electrical Engineering and Computer Science, Case Western Reserve University, Cleveland, OH 44106, United States; School of Mathematical Sciences, Jiangsu University, Jiangsu Province, Zhenjiang, 212013, China ABSTRACT: For a family of time-delay feedforward systems satisfying a linear growth condition, we study the problem of global asymptotic stabilization by digital state and output feedback, respectively, under arbitrarily sparse sampling. Using the Lyapunov–Krasovskii functional method and the feedback domination design, we construct memoryless sampled-data state and/or output feedback controllers that achieve global asymptotic stability of the hybrid closed-loop systems with large delays. Applications of the sampled-data control schemes are demonstrated through an example with simulations. © 2022 Elsevier B.V. Trapiello, C., Puig, V., Rotondo, D. A zonotopic set-invariance analysis of replay attacks affecting the supervisory layer (2021) 157, art. no. 105056, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117795024&doi=10.1016%2fj.sysconle.2021.105056&partnerID=40&md5=c06149240c2153b7a798da03ca22ab54 DOI: 10.1016/j.sysconle.2021.105056 AFFILIATIONS: Advanced Control Systems Group, Automatic Control Department, Universitat Politècnica de Catalunya (UPC), Rambla Sant Nebridi 10, Terrassa, 08222, Spain; Institut de Robòtica i Informàtica Industrial, CSIC-UPC, Llorens i Artigas 4-6, Barcelona, 08028, Spain; Department of Electrical and Computer Engineering (IDE), University of Stavanger (UiS), Kristine Bonnevies vei 22, Stavanger, 4021, Norway ABSTRACT: This paper presents a zonotopic set-invariance analysis of replay attacks affecting the communication network that serves the supervisory layer of complex control systems using an observer-based detection scheme. Depending on the attacker's access to the system's resources, two scenarios are considered: (I) Sensors and controller data are counterfeited; (II) Only sensor measurements are counterfeited. The effect of a physical attack against the plant during the data replay is also taken into consideration. The representation of invariant sets as zonotopes allows to derive analytical expressions for attack detectability under the presence of bounded uncertainties. The validity of the analysis is demonstrated through simulations using a quadruple-tank process. © 2021 Elsevier B.V. Mironchenko, A., Noroozi, N., Kawan, C., Zamani, M. ISS small-gain criteria for infinite networks with linear gain functions (2021) 157, art. no. 105051, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117694633&doi=10.1016%2fj.sysconle.2021.105051&partnerID=40&md5=2e7d52130f1eb6a2eafa352e010fedc5 DOI: 10.1016/j.sysconle.2021.105051 AFFILIATIONS: Faculty of Computer Science and Mathematics, University of Passau, Germany; Institute of Informatics, LMU Munich, Germany; Computer Science Department, University of Colorado Boulder, United States ABSTRACT: This paper provides a Lyapunov-based small-gain theorem for input-to-state stability (ISS) of networks composed of infinitely many finite-dimensional systems. We model these networks on infinite-dimensional ℓ∞-type spaces. A crucial assumption in our results is that the internal Lyapunov gains, modeling the influence of the subsystems on each other, are linear functions. Moreover, the gain operator built from the internal gains is assumed to be subadditive and homogeneous, which covers both max-type and sum-type formulations for the ISS Lyapunov functions of the subsystems. As a consequence, the small-gain condition can be formulated in terms of a generalized spectral radius of the gain operator. By an example, we show that the small-gain condition can easily be checked if the interconnection topology of the network has some sort of symmetry. While our main result provides an ISS Lyapunov function in implication form for the overall network, an ISS Lyapunov function in a dissipative form is constructed under mild extra assumptions. © 2021 Elsevier B.V. Song, R., Wang, B., Zhu, Q. Stabilization by variable-delay feedback control for highly nonlinear hybrid stochastic differential delay equations (2021) 157, art. no. 105041, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117068439&doi=10.1016%2fj.sysconle.2021.105041&partnerID=40&md5=6e0e7003a906d56578f3e2e09eab9bb3 DOI: 10.1016/j.sysconle.2021.105041 AFFILIATIONS: School of Applied Mathematics, Nanjing University of Finance and Economics, Nanjing, Jiangsu, 210023, China; MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, Hunan, 410081, China ABSTRACT: We consider a hybrid SDE (stochastic differential equation) with variable delays, which is unstable and its coefficients satisfy some polynomial growth conditions. We want to find a variable-delays feedback control such that the controlled hybrid SDE with variable delay becomes stable. We establish some novel stability criteria of the controlled SDE with variable delays. Our results improve the existing results from hybrid SDEs with constant-delays to hybrid SDEs with variable-delays. Finally, an example is given to confirm our results. © 2021 Elsevier B.V. Zheng, S., Ahn, C.K., Shi, P., Xie, Y. Prescribed finite-time consensus with severe unknown nonlinearities and mismatched disturbances (2021) 157, art. no. 105047, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116937964&doi=10.1016%2fj.sysconle.2021.105047&partnerID=40&md5=26031431880f87029f871df95cceb2f7 DOI: 10.1016/j.sysconle.2021.105047 AFFILIATIONS: School of Automation, China University of Geosciences, Wuhan, 430074, China; Hubei key Laboratory of Advanced Control and Intelligent Automation for Complex Systems, Wuhan, 430074, China; Engineering Research Center of Intelligent Geodetection Technology Ministry of Education, China University of Geosciences, Wuhan, 430074, China; School of Electrical Engineering, Korea University, Seoul, 136-701, South Korea; School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, SA 5005, Australia; School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China ABSTRACT: This paper considers the problem of prescribed finite-time leader-following consensus for a class of second-order multi-agent systems (MAS). Compared to the existing methods, the dynamics of the followers in the proposed method is rather general, containing some severe unknown nonlinearities and mismatched disturbances. First, a time-varying distributed observer is proposed to estimate the leader information in prescribed finite time. The leader is driven by a control input that is unknown to all the followers. Then, a new composite controller with a time-varying disturbance observer is presented. By gracefully combining the barrier Lyapunov functions and logic-based switching rules, we show that the unknown nonlinearities and mismatched disturbances can be well handled. Thus, the prescribed finite-time consensus problem can be solved. Finally, by the properties of Lyapunov functions and time-varying gains, we present a new method to show that the control signals are bounded. A simulation example is provided to verify the effectiveness of the proposed method. © 2021 Elsevier B.V. Liu, X., Lin, W., Zhao, C., Hu, Y. Sampled-data control of a class of time-delay nonlinear systems via memoryless feedback (2021) 157, art. no. 105048, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116920499&doi=10.1016%2fj.sysconle.2021.105048&partnerID=40&md5=635fad5ecddffd04af375ed2988c8c5f DOI: 10.1016/j.sysconle.2021.105048 AFFILIATIONS: School of Electronic Engineering, Dongguan University of Technology, Dongguan, Guangdong Province 523808, China; Department of Electrical, Computer, and Systems Engineering, Case Western Reserve University, Cleveland, OH 44106, United States; School of Mathematical Sciences, Jiangsu University, Zhenjiang, Jiangsu Province 212013, China ABSTRACT: We prove that under a linear growth condition, a family of time-delay nonlinear systems is globally stabilizable by memoryless sampled-data state and output feedback, respectively, if the input delay and sampling period are not too big although the state delays are permitted to be large. The proofs rely on the construction of sampled-data feedback controllers and the Lyapunov–Krasovskii functional method. The designed memoryless controllers achieve global asymptotic stabilization of the hybrid closed-loop systems with time-delay and are easily implementable by computers owing to their discrete-time and delay-free nature. © 2021 Elsevier B.V. Kravaris, C., Venkateswaran, S. Functional observers with linear error dynamics for nonlinear systems (2021) 157, art. no. 105021, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114987038&doi=10.1016%2fj.sysconle.2021.105021&partnerID=40&md5=fd32ec29754a64205312fc4494a0fdd7 DOI: 10.1016/j.sysconle.2021.105021 AFFILIATIONS: Texas A&M University, College StationTX 77843-3122, United States ABSTRACT: In this work, the problem of designing observers for estimating a single nonlinear functional of the state is formulated for general nonlinear systems. Notions of functional observer linearization are also formulated, in terms achieving exactly linear error dynamics in transformed coordinates and with prescribed rate of decay of the error. Necessary and sufficient conditions for the existence of a lower-order functional observer with linear dynamics are derived. The results provide a direct generalization of Luenberger's linear theory of functional observers to nonlinear systems. © 2021 Elsevier B.V. Borkar, V.S., Chandak, S. Prospect-theoretic Q-learning (2021) 156, art. no. 105009, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112524046&doi=10.1016%2fj.sysconle.2021.105009&partnerID=40&md5=6445ed1ecdca6ccf7993eed0f79bd8e6 DOI: 10.1016/j.sysconle.2021.105009 AFFILIATIONS: Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India ABSTRACT: We consider a prospect theoretic version of the classical Q-learning algorithm for discounted reward Markov decision processes, wherein the controller perceives a distorted and noisy future reward, modeled by a nonlinearity that accentuates gains and under-represents losses relative to a reference point. We analyze the asymptotic behavior of the scheme by analyzing its limiting differential equation and using the theory of monotone dynamical systems to infer its asymptotic behavior. Specifically, we show convergence to equilibria, and establish some qualitative facts about the equilibria themselves. © 2021 Elsevier B.V. Guo, J., Cheng, J., Diao, J.-D. System identification with binary-valued output observations under either-or communication and data packet dropout (2021) 156, art. no. 105010, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112470794&doi=10.1016%2fj.sysconle.2021.105010&partnerID=40&md5=6703bcb078a909f87163a12a9363046a DOI: 10.1016/j.sysconle.2021.105010 AFFILIATIONS: School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Key Laboratory of Knowledge Automation for Industrial Processes, Ministry of Education, Beijing, 100083, China; Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology, Beijing, China ABSTRACT: The event-triggered mechanism can effectively save communication resources. However, if the packet loss occurs during data transmission, the receiving center is unable to distinguish between “no data has been sent since the event is not triggered” and “the data has been sent, but the packet is lost”. This paper aims to address this issue in the system identification with binary-valued output observations under either-or communication and data packet dropout. For the case that the packet loss probability is known, the identification algorithm is designed, and the strong convergence and asymptotic normality of the algorithm are given. For the case that the packet loss probability is unknown, a compensation-oriented identification approach is proposed by improving the either-or communication mechanism. The identification algorithm is designed to jointly estimate the system parameter and the packet loss probability, then its convergence and asymptotic normality are derived. The minimum communication rate is given within the allowable range of estimation error and the implementation of the optimal communication mechanism is provided. The validity and rationality of the results are verified by numerical simulation. © 2021 Elsevier B.V. Cao, K., Qian, C., Gu, J. Sampled-data control of a class of uncertain nonlinear systems based on direct method (2021) 155, art. no. 105000, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111543676&doi=10.1016%2fj.sysconle.2021.105000&partnerID=40&md5=185d2be7ed8b129f34d40383ccae3d6c DOI: 10.1016/j.sysconle.2021.105000 AFFILIATIONS: School of Electrical Engineering, Nantong University, Nantong, JiangSu, 226019, China; Department of Electrical and Computer Engineering, University of Texas at San Antonio, San AntonioTX 78249, United States ABSTRACT: This paper employs the direct method to design sampled-data state/output feedback controller for a class of uncertain nonlinear systems under a general linear growth condition. Both state feedback controller and observer are constructed directly in the discrete-time domain for the difference-integral systems equivalent to the continuous-time systems. To dominate the influence of the uncertain nonlinearities, a co-design process is used to determine the sampling period and scaling gain together. Compared to the emulation method, the direct co-design method can handle a broader class of nonlinear systems and has more flexibility in choosing the sampling period that is less restrictive for digital implementation. © 2021 Mukherjee, S., Bai, H., Chakrabortty, A. Model-based and model-free designs for an extended continuous-time LQR with exogenous inputs (2021) 154, art. no. 104983, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109527562&doi=10.1016%2fj.sysconle.2021.104983&partnerID=40&md5=9589468556d16730f91407ead4879e00 DOI: 10.1016/j.sysconle.2021.104983 AFFILIATIONS: Optimization and Control Group, Pacific Northwest National Laboratory, United States; Mechanical and Aerospace Engineering Department, Oklahoma State University, United States; Department of Electrical and Computer Engineering, North Carolina State University, United States ABSTRACT: We present an extended linear quadratic regulator (LQR) design for continuous-time linear time invariant (LTI) systems in the presence of exogenous inputs with a novel feedback control structure. We first propose a model-based solution with cost minimization guarantees for states and inputs using dynamic programming (DP) that out-performs classical LQR with exogenous inputs. The control law consists of a combination of the optimal state feedback and an additional optimal term which is dependent on the exogenous inputs. The control gains for the two components are obtained by solving a set of matrix differential equations. We provide these solutions for both finite horizons and steady state cases. In the second part of the paper, we formulate a reinforcement learning (RL) based algorithm which does not need any model information except the input matrix, and can compute approximate steady-state extended LQR gains using measurements of the states, the control inputs, and the exogenous inputs. Both model-based and data-driven optimal control algorithms are tested with a numerical example under different exogenous inputs showcasing the effectiveness of the designs. © 2021 Zhang, Y.-L., Zhu, M., Li, D., Wang, J.-M. Static boundary feedback stabilization of an anti-stable wave equation with both collocated and non-collocated measurements (2021) 154, art. no. 104967, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109064025&doi=10.1016%2fj.sysconle.2021.104967&partnerID=40&md5=7e198116833a59ada84789a66d214382 DOI: 10.1016/j.sysconle.2021.104967 AFFILIATIONS: School of Mathematics and Statistics, Beijing Institute of Technology, Beijing, 100081, China; Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China; China State Key Laboratory of Power Systems and Generation Equipment, Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China ABSTRACT: In this paper, we consider the stabilization of a wave equation with an unknown anti-stable injection on the left boundary and the control input on the right boundary, where there are both collocated and non-collocated measurements. A static output feedback control law is designed to stabilize the wave equation. The value ranges of the feedback gains are given, such that all eigenvalues of the closed-loop system are shown to be inside the left-half complex plane by applying the Nyquist criterion for distributed parameter systems. Then the exponential stability of the closed-loop system is established. Numerical simulations are presented to verify the effectiveness of the proposed feedback control law. © 2021 Elsevier B.V. Dong, H., Li, J., Li, C., Qi, D. Continuous-time distributed Nash strategy over switching topologies with gain adaptation (2021) 153, art. no. 104955, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107040351&doi=10.1016%2fj.sysconle.2021.104955&partnerID=40&md5=ed19c4287550dfda80e199926c2fb66b DOI: 10.1016/j.sysconle.2021.104955 AFFILIATIONS: College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China ABSTRACT: This paper investigates the Nash equilibrium seeking problem among networked multi-player game over directed and switching topologies. To this end, a fully distributive gain adaptation strategy is proposed to make sure all players are updated without global information or initialization, and it is proved rigorously that the proposed scheme works well under a switching digraph and admits global convergence to the Nash equilibrium. © 2021 Elsevier B.V. Wijnbergen, P., Jeeninga, M., Besselink, B. Nonlinear spacing policies for vehicle platoons: A geometric approach to decentralized control (2021) 153, art. no. 104954, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105870766&doi=10.1016%2fj.sysconle.2021.104954&partnerID=40&md5=fbb3bbf6f6e3ee2358276503f68b0553 DOI: 10.1016/j.sysconle.2021.104954 AFFILIATIONS: Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands; ENgineering and TEchnology institute Groningen, University of Groningen, Groningen, Netherlands ABSTRACT: In this paper a decentralized approach to the platooning problem with nonlinear spacing policies is considered. A predecessor–follower control structure is presented in which a vehicle is responsible for tracking of a desired spacing policy with respect to its predecessor, regardless of the control action of the latter. From the perspective of geometric control theory, we state necessary and sufficient conditions for the existence of decentralized controllers that guarantee tracking and asymptotic stabilization of a general nonlinear spacing policy. Moreover, all nonlinear spacing policies for which there exists a decentralized state feedback controller that achieves asymptotic tracking are characterized. It is shown that string stability is a consequence of the choice of spacing policy and sufficient conditions for a spacing policy to imply string stability are given. As an example, we fully characterize all state feedback controllers that achieve the control goals for a given nonlinear spacing policy, guaranteeing asymptotic tracking for a heterogeneous platoon. The results are illustrated through simulations. © 2021 The Author(s) Borkar, V.S. A concentration bound for contractive stochastic approximation (2021) 153, art. no. 104947, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105098862&doi=10.1016%2fj.sysconle.2021.104947&partnerID=40&md5=b46a38117e872d6534a04d548b96dc59 DOI: 10.1016/j.sysconle.2021.104947 AFFILIATIONS: Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India ABSTRACT: We derive a ‘high probability’ concentration bound for stochastic approximation schemes for finding the fixed point of a contraction map, and illustrate its applications in reinforcement learning for approximate dynamic programming. © 2021 Elsevier B.V. Liu, Z., Nojavanzadeh, D., Saberi, D., Saberi, A., Stoorvogel, A.A. Scale-free protocol design for regulated state synchronization of homogeneous multi-agent systems with unknown and non-uniform input delays (2021) 152, art. no. 104927, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104680545&doi=10.1016%2fj.sysconle.2021.104927&partnerID=40&md5=8c30bfd40f93390bfc694f3936bcf8da DOI: 10.1016/j.sysconle.2021.104927 AFFILIATIONS: College of Information Science and Engineering, Northeastern University, Shenyang, China; School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA, United States; Stanford University, Stanford, CA, United States; Department of Electrical Engineering, Mathematics and Computer Science, University of Twente, Enschede, Netherlands ABSTRACT: This paper studies regulated state synchronization of homogeneous networks of continuous- or discrete-time non-introspective agents in the presence of unknown and nonuniform input delays. A scale-free design is proposed utilizing neighborhood-based collaborative protocols, which do not need any knowledge of the communication topology of the network such as the spectrum of the associated Laplacian matrix or the size of the network (i.e. the number of agents). An upper bound for the input delay tolerance is obtained, which explicitly depends on agent dynamics but is independent of the network. © 2021 Na, J., Huang, Y., Liu, T., Zhu, Q. Reinforced adaptive parameter estimation with prescribed transient convergence performance (2021) 149, art. no. 104880, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100373078&doi=10.1016%2fj.sysconle.2021.104880&partnerID=40&md5=2832f51f335453c3044361e41cb1f781 DOI: 10.1016/j.sysconle.2021.104880 AFFILIATIONS: Faculty of Mechanical and Electrical Engineering, Kunming University of Science and Technology, Kunming, 650500, China; School of Control Science and Engineering, Dalian University of Technology, Dalian, 116024, China; Department of Engineering Design and Mathematics, University of the West of England, Bristol, BS16 1QY, United Kingdom ABSTRACT: Although adaptive parameter estimation (APE) has been studied for decades, quantifying the transient estimation error convergence performance (e.g., overshoot and convergence rate) that is essential for system safety and reliability is more difficult than the steady-state convergence analysis. To address this issue, a new APE method with prescribed convergence performance is proposed in this paper. The main idea is to incorporate a prescribed performance function (PPF) into the design of adaptive laws to predefine the estimation error convergence boundary. For this purpose, a filtering approach is first introduced to extract the estimation error by using the measured system input and output. An estimation error transformation is then introduced to derive intermediate variables for establishing the adaptive law. With the well-recognized persistent excitation (PE) condition, it is proved that the estimation error for constant parameters can be strictly guaranteed within a predefined boundary. The robustness against bounded disturbances is also examined. With this framework, the PE condition can be verified by examining the positive definiteness of an induced intermediate matrix. A simulation example is given to show the effectiveness of the proposed algorithm. © 2021 Elsevier B.V. Jiao, J., Trentelman, H.L., Camlibel, M.K. H2 suboptimal output synchronization of heterogeneous multi-agent systems (2021) 149, art. no. 104872, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099844585&doi=10.1016%2fj.sysconle.2021.104872&partnerID=40&md5=27053adef2e11cd0ac65c881a5038194 DOI: 10.1016/j.sysconle.2021.104872 AFFILIATIONS: Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, 9700 AK, Netherlands ABSTRACT: This paper deals with the H2 suboptimal output synchronization problem for heterogeneous linear multi-agent systems. Given a multi-agent system with possibly distinct agents and an associated H2 cost functional, the aim is to design output feedback based protocols that guarantee the associated cost to be smaller than a given upper bound while the controlled network achieves output synchronization. A design method is provided to compute such protocols. For each agent, the computation of its two local control gains involves two Riccati inequalities, each of dimension equal to the state space dimension of the agent. A simulation example is provided to illustrate the performance of the proposed protocols. © 2021 The Author(s) Zhang, F. Stochastic maximum principle of mean-field jump–diffusion systems with mixed delays (2021) 149, art. no. 104874, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099621454&doi=10.1016%2fj.sysconle.2021.104874&partnerID=40&md5=094c4f5af31796bae368a7989b8d959b DOI: 10.1016/j.sysconle.2021.104874 AFFILIATIONS: School of Mathematics and Quantitative Economics, Shandong University of Finance and Economics, Jinan, 250014, China ABSTRACT: This paper is concerned with one kind of stochastic optimal control problem of mean-field jump–diffusion system with moving-average as well as pointwise delays. By means of the maximum principle, both necessary and sufficient optimality conditions are established. Two kinds of adjoint equations are used, which are shown to be equivalent. That is, a unified adjoint equation is provided. © 2021 Elsevier B.V. Zheng, M., Ohta, Y. Bayesian positive system identification: Truncated Gaussian prior and hyperparameter estimation (2021) 148, art. no. 104857, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099214761&doi=10.1016%2fj.sysconle.2020.104857&partnerID=40&md5=aa5235e128607cd522665ba1cc42e5b2 DOI: 10.1016/j.sysconle.2020.104857 AFFILIATIONS: Department of Applied Mathematics and Physics, Kyoto University, Kyoto, 6068501, Japan ABSTRACT: Bayesian methods have been extended for the linear system identification problem in the past ten years. The traditional Bayesian identification selects a Gaussian prior and considers the tuning of kernels, i.e., the covariance matrix of a Gaussian prior. However, Gaussian priors cannot express the system information appropriately for identifying a positive finite impulse response (FIR) model. This paper exploits the truncated Gaussian prior and develops Bayesian identification procedures for positive FIR models. The proposed parameterizations in the truncated Gaussian prior can reflect the decay rate and the correlation of the impulse response of the system to be identified. The expectation–maximization (EM) algorithm is tailored to the hyperparameter estimation problem of positive system identification with the truncated Gaussian prior. Numerical experiments compare the truncated Gaussian prior to the traditional Gaussian prior for positive FIR system identification. The simulation results demonstrate that the truncated Gaussian prior outperforms the Gaussian prior. © 2020 Elsevier B.V. Li, Z., Xu, L., Xu, L. Global attracting sets and exponential stability of stochastic partial functional differential equations (2021) 148, art. no. 104859, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098865904&doi=10.1016%2fj.sysconle.2020.104859&partnerID=40&md5=d132c61ea730a31902cf649e497e3c31 DOI: 10.1016/j.sysconle.2020.104859 AFFILIATIONS: School of Information and Mathematics, Yangtze University, Jingzhou, Hubei, 434023, China; Department of Applied Mathematics, Zhejiang University of Technology, Hangzhou, 310023, China ABSTRACT: This paper is concerned with the global attracting sets and the exponential stability in the mean square of mild solutions for stochastic functional partial differential equations. Some new sufficient conditions ensuring the existence of the global attracting sets and the exponential stability in the mean square of mild solutions for the considered equations are established by introducing approximating systems with strong solutions and using a limiting argument. Finally, some examples are investigated to illustrate the theory. © 2020 Elsevier B.V. Cordoni, F., Di Persio, L., Muradore, R. Stabilization of bilateral teleoperators with asymmetric stochastic delay (2021) 147, art. no. 104828, . Cited 4 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097052380&doi=10.1016%2fj.sysconle.2020.104828&partnerID=40&md5=a364f585a45e1708ce3902c83c02507e DOI: 10.1016/j.sysconle.2020.104828 AFFILIATIONS: Department of Computer Science, University of Verona, Strada le Grazie, 15, Verona, 37134, Italy ABSTRACT: In this paper we consider the problem of position tracking and error boundedness for a master–slave teleoperation system when the communication channel is characterized by a time-varying stochastic delay. In particular, we assume the delay to be a time-varying Markov regime switching process. Our solution is based on a suitable proportional–derivative (PD) like controller. Exploiting a Lyapunov–Krasovskii functional approach, we are able to show that the velocity and position errors remain bounded, provided specific inequality is satisfied. Moreover, zero steady-state position error is achieved when the human operator and the environment do not interact with the system. In order to be able to exploit Lyapunov–Krasovskii approach we need to lift the underlying process to an infinite-dimensional process taking values in a suitable Banach space so that, in the new space, the process is a Markov process. Our conditions for guaranteeing boundedness and the zero steady-state position tracking error are the natural generalization of the deterministic counterparts available in the literature, i.e. when considering the trivial case of a single-state Markov process previous results are recovered. Simulation results show the effectiveness of the proposed approach. © 2020 Elsevier B.V. Lhachemi, H., Prieur, C. Nonlinear boundary output feedback stabilization of reaction–diffusion equations (2022) 166, art. no. 105301, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133673591&doi=10.1016%2fj.sysconle.2022.105301&partnerID=40&md5=a18c7f163633a2751ce11839b8e5cda8 DOI: 10.1016/j.sysconle.2022.105301 AFFILIATIONS: Université Paris-Saclay, CNRS, CentraleSupélec, Laboratoire des signaux et systèmes, Gif-sur-Yvette, 91190, France; Université Grenoble Alpes, CNRS, Grenoble-INP, GIPSA-lab, Grenoble, F-38000, France ABSTRACT: This paper studies the design of a finite-dimensional output feedback controller for the stabilization of a reaction–diffusion equation in the presence of a sector nonlinearity in the boundary input. Due to the input nonlinearity, classical approaches relying on the transfer of the control from the boundary into the domain with explicit occurrence of the time-derivative of the control cannot be applied. In this context, we first demonstrate using Lyapunov direct method how a finite-dimensional observer-based controller can be designed, without using the time derivative of the boundary input as an auxiliary command, in order to achieve the boundary stabilization of general 1-D reaction–diffusion equations with Robin boundary conditions and a measurement selected as a Dirichlet trace. We extend this approach to the case of a control applying at the boundary through a sector nonlinearity. We show from the derived stability conditions the existence of a size of the sector (in which the nonlinearity is confined) so that the stability of the closed-loop system is achieved when selecting the dimension of the observer to be large enough. © 2022 Elsevier B.V. Lamouchi, R., Raissi, T., Amairi, M., Aoun, M. On interval observer design for active Fault Tolerant Control of Linear Parameter-Varying systems (2022) 164, art. no. 105218, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130126718&doi=10.1016%2fj.sysconle.2022.105218&partnerID=40&md5=a6a5dac4c11a8622ed641e0369da31a6 DOI: 10.1016/j.sysconle.2022.105218 AFFILIATIONS: Research Laboratory Modeling, Analysis and Control of Systems (MACS) LR16ES22, National Engineering School of Gabes, University of Gabes 6029 Gabes, Tunisia; Conservatoire National des Arts et Métiers (CNAM), Cedric-Lab 292, Rue St-Martin, Paris Cedex 03, 75141, France ABSTRACT: This paper proposes an active Fault Tolerant Control (FTC) scheme for polytopic uncertain Linear Parameter-Varying (LPV) systems subject to uncertainties and actuator faults. First, a fault estimation interval observer is designed to estimate the system state and the actuator fault. A novel approach is developed using the L∞ norm to attenuate the effects of the uncertainties and to improve the accuracy of the proposed observer. Then, based on the fault estimation information, the FTC strategy is designed using a linear state feedback control law and H∞ technique to compensate actuator faults and maintain system performance and stability, even under faulty conditions. Finally, the effectiveness of the proposed method is demonstrated by its application to a vehicle lateral dynamic nonlinear model. © 2022 Elsevier B.V. Hao, N., He, F., Hou, Y., Yao, Y. Graph-based observability analysis for mutual localization in multi-robot systems (2022) 161, art. no. 105152, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124707620&doi=10.1016%2fj.sysconle.2022.105152&partnerID=40&md5=5301d172cfc1c0d8603168e94d5136c5 DOI: 10.1016/j.sysconle.2022.105152 AFFILIATIONS: School of Astronautics, Harbin Institute of Technology, Harbin, 150000, China ABSTRACT: In this paper, we investigate the observability properties of a type of nonlinear system, which often arises from multi-robot mutual localization problems. An extended relative position measurement graph (ERPMG) is constructed to integrate all influencing factors of observability, including the motion inputs and relative position measurements of robots. We analyze the observability of such systems by bridging the connection between the nonlinear observability matrix and the spectral matrix of the ERPMG. A necessary and sufficient observability condition for MRS represented by spectral graph properties of the ERPMG is derived for the first time. We then develop an algorithm to efficiently check the observability and further validate the proposed theoretical results by simulation experiments. © 2022 Elsevier B.V. Berger, T. Feedback control of the COVID-19 pandemic with guaranteed non-exceeding ICU capacity (2022) 160, art. no. 105111, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122530622&doi=10.1016%2fj.sysconle.2021.105111&partnerID=40&md5=e30817babd9d174ce080af3130ba9c5b DOI: 10.1016/j.sysconle.2021.105111 AFFILIATIONS: Universität Paderborn, Institut für Mathematik, Warburger Str. 100, Paderborn, 33098, Germany ABSTRACT: In this paper we investigate feedback control techniques for the COVID-19 pandemic which are able to guarantee that the capacity of available intensive care unit beds is not exceeded. The control signal models the social distancing policies enacted by local policy makers. We propose a control design based on the bang–bang funnel controller which is robust with respect to uncertainties in the parameters of the epidemiological model and only requires measurements of the number of individuals who require medical attention. Simulations illustrate the efficiency of the proposed controller. © 2021 Elsevier B.V. Yang, X., Li, H. On state feedback asymptotical stabilization of probabilistic Boolean control networks (2022) 160, art. no. 105107, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122011670&doi=10.1016%2fj.sysconle.2021.105107&partnerID=40&md5=3e1ca6a936ceebf161232133194963d2 DOI: 10.1016/j.sysconle.2021.105107 AFFILIATIONS: School of Mathematics and Statistics, Shandong Normal University, Jinan, 50014, China ABSTRACT: This article devotes to the design of all state feedback controllers for the asymptotical stabilization of probabilistic Boolean control networks (PBCNs). Firstly, a class of complete family of reachable sets (CFRSs) is constructed. Based on the CFRSs, all possible state feedback controllers are designed to stabilize PBCNs to a given control-fixed point in distribution. Secondly, by removing the finite-time stabilizers from the controllers that make PBCNs stabilizable in distribution, all state feedback controllers which asymptotically stabilize PBCNs with probability one are further obtained. Thirdly, the CFRSs are applied to solve the problem of asymptotical set stabilization. Finally, an example of lac operon in the Escherichia coli is given to illustrate the proposed methods. © 2021 Elsevier B.V. Krishnamurthy, P., Khorrami, F. Resilient redundancy-based control of cyber–physical systems through adaptive randomized switching (2021) 158, art. no. 105066, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119044784&doi=10.1016%2fj.sysconle.2021.105066&partnerID=40&md5=064bd4c9589a65a35361cb729df2cbe9 DOI: 10.1016/j.sysconle.2021.105066 AFFILIATIONS: Department of ECE, NYU Tandon School of Engineering, 5 MetroTech Center, Brooklyn, NY 11201, United States ABSTRACT: A switching based approach using multiple parallel redundant controller implementations is developed to improve resiliency of cyber–physical systems (CPSs). Hardware/software redundancy is known to be a powerful technique for resiliency to mitigate effects of adversaries who infiltrate and maliciously modify a subset of the redundant subsystems. While redundant subsystems are typically combined using fail-over/backup and voting mechanisms, the proposed approach considers a time-division multiplexer using which one of multiple controller implementations is selected at each time instant to drive the input of the controlled system. Through detailed analysis of the switched system, it is shown that time-division multiplexing between redundant controllers can be used to mitigate the impact to stability and/or performance of the closed-loop CPS due to adversarial modifications of subsets of controllers. Additionally, we show that adversarial impact to the closed-loop CPS can be reduced over time by switching among the controllers in a probabilistic manner (rather than round-robin) and by dynamically adapting probabilities of switching to each controller. The efficacy of the proposed adaptive randomized switching algorithm is shown through simulation studies on two illustrative examples: a simple third-order system and a more real-world single-machine-infinite-bus system. © 2021 Elsevier B.V. Eising, J., Trentelman, H.L. Informativity of noisy data for structural properties of linear systems (2021) 158, art. no. 105058, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118496142&doi=10.1016%2fj.sysconle.2021.105058&partnerID=40&md5=4e573b27777505de884b3f561d71f2bf DOI: 10.1016/j.sysconle.2021.105058 AFFILIATIONS: Bernoulli Institute for Mathematics, Computer Science, and Artificial Intelligence, University of Groningen, Nijenborgh 9, 9747 AG, Groningen, Netherlands ABSTRACT: This paper deals with developing tests for checking whether an unknown system has certain structural properties. The tests that we are aiming at are in terms of noisy input–state–output data obtained from the unknown system. Since, in general, the data do not determine the unknown system uniquely, many systems are compatible with the same set of data. Therefore we cannot apply system identification and apply existing, model based, tests. Instead, we will use the concept of informativity, and establish tests for informativity of the given noisy data. We will do this for a range of system properties, among which strong observability and detectability and strong controllability and stabilizability. These informativity tests will be in terms of rank tests on polynomial matrices that can be constructed from the noisy data. We will also set up a geometric framework for informativity analysis. Within that framework we will give geometric tests for informativity for strong observability, observability, and left-invertibility. © 2021 The Author(s) Ge, Z. Exact observability and stability of stochastic implicit systems (2021) 157, art. no. 105029, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115435490&doi=10.1016%2fj.sysconle.2021.105029&partnerID=40&md5=f29809c25c32b906ff71498704bcaf57 DOI: 10.1016/j.sysconle.2021.105029 AFFILIATIONS: School of Mathematics and Statistics, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049, China ABSTRACT: This paper discusses the exact observability and stability of the stochastic implicit systems. Firstly, the conditions for the existence and uniqueness of the impulse solution to stochastic implicit systems are given by stochastic Laplace transform. Secondly, the necessary and sufficient conditions for the exact observability of stochastic implicit systems are derived by the matrix theory. Thirdly, the application of exact observability of the stochastic implicit systems to its stability is discussed and sufficient conditions for the stability of systems considered are derived in terms of linear matrix inequalities. Finally, some examples are given to illustrate the effectiveness of the obtained theoretical results. © 2021 Elsevier B.V. Drăgan, V., Costa, E.F., Popa, I.-L., Aberkane, S. Exact detectability: Application to generalized Lyapunov and Riccati equations (2021) 157, art. no. 105032, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115175288&doi=10.1016%2fj.sysconle.2021.105032&partnerID=40&md5=ebb4953bd3b08d8771cc1b2b5e8cdb27 DOI: 10.1016/j.sysconle.2021.105032 AFFILIATIONS: Institute of Mathematics ”Simion Stoilow” of the Romanian Academy, P.O. Box 1-764, Bucharest, RO-014700, Romania; the Academy of the Romanian Scientists, Romania; Instituto de Ciências Matemáticas e de Computação, Universidade de São Paulo, São Carlos-SPCEP 13566-590, Brazil; Department of Mathematics, ”1 Decembrie 1918” University of Alba Iulia, Alba Iulia, 510009, Romania; Université de Lorraine, CRAN, UMR 7039, Campus Sciences, BP 70239, Vandoeuvre-les-Nancy Cedex, 54506, France; CNRS, CRAN, UMR 7039, France ABSTRACT: This paper is devoted to the application of the recently developed results about exact detectability of a large class of time-varying hybrid stochastic systems (Drăgan et al., 2020). More specifically, we will show from one side the connection between this new detectability notion and the derivation of a criterion for exponential stability in mean square for this class of systems. In the second part, we will show the central role played by exact detectability in Riccati equations arising in linear quadratic (LQ) regulator problems for such stochastic systems: it is a necessary and sufficient condition for the Riccati equation to have a unique positive semi-definite and stabilizing solution. © 2021 Fu, J., Ma, Z., Fu, Y., Chai, T. Hybrid adaptive control of nonlinear systems with non-Lipschitz nonlinearities (2021) 156, art. no. 105012, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112740441&doi=10.1016%2fj.sysconle.2021.105012&partnerID=40&md5=7c3698563a056de8820f2c1f654bf680 DOI: 10.1016/j.sysconle.2021.105012 AFFILIATIONS: State Key Laboratory of Synthetical Automation for Process Industries (Northeastern University), Shenyang, 110819, China; Department of Electrical and computer Engineering, Iowa State University, Ames, IA 50010, United States ABSTRACT: In this paper, a hybrid adaptive control method is proposed for a class of discrete-time multiple-inputs-multiple-outputs (MIMO) systems with non-Lipschitz nonlinearities by introducing a novel Riemann sum operator with variable step size. Firstly, for the first order approximation of the original nonlinear system, a linear adaptive controller is developed to assure essential boundedness of all the signals but with unsatisfactory performance. Secondly, an artificial neural network (ANN)-based nonlinear adaptive controller is designed for the original system to improve response performance, nevertheless, may lead to instability. Thirdly, switching mechanism between the linear adaptive controller and the nonlinear one is suitably designed to achieve stability and improved output tracking performance simultaneously. Finally, a numerical example is provided to verify the effectiveness of the proposed method. © 2021 Elsevier B.V. Liu, J., Guo, B.-Z. Uniformly semidiscretized approximation for exact observability and controllability of one-dimensional Euler–Bernoulli beam (2021) 156, art. no. 105013, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112404173&doi=10.1016%2fj.sysconle.2021.105013&partnerID=40&md5=40d8854aff5a84bbd07e5f9a82889a76 DOI: 10.1016/j.sysconle.2021.105013 AFFILIATIONS: School of Mathematical Sciences, Shanxi University, Taiyuan, 030006, China; School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China ABSTRACT: In this paper, a spacial semidiscretized finite difference scheme developed in our previous work (Liu and Guo, 2019) is used to approximate exact observability and controllability for Euler–Bernoulli beam control system. The uniform observability inequality is proved by discrete energy multiplier technique. The uniform controllability and uniform boundedness of the discrete controls are also developed. Compared with the existing literature, the proposed approach has achieved potentially the following advantages: (a) It removes the introduction of the numerical viscosity term to achieve uniformity; (b) It can deal with any type of boundary conditions without help of the spectral analysis which is limited only for some special boundary conditions; (c) The proofs of the uniform observability and controllability are simplified significantly with the similar techniques in dealing with the continuous counterpart. © 2021 Elsevier B.V. Li, R., Zhang, Q., Zhang, J., Chu, T. Distributional observability of probabilistic Boolean networks (2021) 156, art. no. 105001, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112286807&doi=10.1016%2fj.sysconle.2021.105001&partnerID=40&md5=d916bb7481bc3ff04e379736186e6e63 DOI: 10.1016/j.sysconle.2021.105001 AFFILIATIONS: School of Mathematical Sciences, Dalian University of Technology, Dalian, 116024, China; Key Laboratory for Computational Mathematics and Data Intelligence of Liaoning Province, Dalian University of Technology, Dalian, 116024, China; School of Information Technology and Management, University of International Business and Economics, Beijing, 100029, China; College of Artificial Intelligence, Nankai University, Tianjin, 300350, China; College of Engineering, Peking University, Beijing, 100871, China ABSTRACT: A probabilistic Boolean network (PBN) is a discrete network composed of a family of Boolean networks together with a set of probabilities governing the selection of a Boolean network at each time step. We introduce in this paper a novel observability problem for PBNs. Specifically, we assume that the values of the initial state of the PBN are not known with certainty, but can be described by probability distributions. We ask ourselves under which conditions it is possible to uniquely determine the probability distribution of initial states when giving only knowledge of the evolution of the probability distributions of network outputs. We propose a complete answer to this problem using a linear algebra approach. Several examples, both artificial and real-world, are given and illustrate the viability of the proposed theoretical results. © 2021 Elsevier B.V. Lin, L., Cao, J., Zhu, S., Shi, P. Minimum-time and minimum-triggering impulsive stabilization for multi-agent systems over finite fields (2021) 155, art. no. 104991, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111986210&doi=10.1016%2fj.sysconle.2021.104991&partnerID=40&md5=19e457ac8d044b373e96c9781d2e89c2 DOI: 10.1016/j.sysconle.2021.104991 AFFILIATIONS: Jiangsu Provincial Key Laboratory of Networked Collective Intelligence, and School of Mathematics, Southeast University, Nanjing, 210096, China; Yonsei Frontier Lab, Yonsei University, Seoul, South Korea; School of Electrical and Electronic Engineering, The University of Adelaide, Adelaide, SA 5005, Australia ABSTRACT: This paper investigates the problem of stabilization for multi-agent systems over finite fields via two types of impulsive control, that is, time-triggered impulsive control (TTIC) and state-triggered impulsive control (STIC). Inspired by the fact that finite-field networks (FFNs) cannot achieve stability at a nonzero state over the finite fields Fp,p>2, two kinds impulse-controlled FFNs (ICFFNs) are introduced subject to time-triggering sequence and state-triggering set, respectively. In order to save time and control cost, the minimum-time control and minimum-triggering control of FFNs are both investigated. The time-optimal and triggering-optimal TTIC and STIC are successively designed. It reveals that designing such optimal TTIC for stabilizing ICFFNs can be transformed into finding the shortest path in the pretreated transition graph, and designing such optimal STIC for the global stabilization of ICFFNs is converted into finding the minimum spanning in-tree. Two examples are given to illustrate the control design procedures. Finally, we discuss the applications of the proposed control design methods on the synchronization problem and the switched FFNs including deterministic switched FFNs, probabilistic FFNs and Markovian jumping FFNs. © 2021 Elsevier B.V. Ammari, K., Alaoui, S.E., Ouzahra, M. Feedback stabilization of linear and bilinear unbounded systems in Banach space (2021) 155, art. no. 104987, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109644052&doi=10.1016%2fj.sysconle.2021.104987&partnerID=40&md5=5f72e93e940849f91964cc75ee8ec56d DOI: 10.1016/j.sysconle.2021.104987 AFFILIATIONS: UR Analysis and Control of PDE's, UR 13E64, Department of Mathematics, Faculty of Sciences of Monastir, University of Monastir, Monastir, 5019, Tunisia; Laboratory MMPA, Department of mathematics & informatics, ENS. University of Sidi Mohamed Ben Abdellah. Fes, Morocco ABSTRACT: We consider linear control systems of the form ẋ(t)=Ax(t)−μBCx(t) where μ is a positive real parameter, A is the state operator and generates a linear C0−semigroup of contractions S(t) on a Banach space X, B and C are respectively the operators of control and observability, which are defined in appropriate spaces in which they are unbounded in some sense. We aim to show the exponential stability of the above system under sufficient conditions which are expressed in terms of admissibility and observability properties. The uniform exponential stabilization using bilinear control is considered as well. Applications to transport and heat equations are also provided. © 2021 Elsevier B.V. Chen, J., Rong, Y., Zhu, Q., Chandra, B., Zhong, H. A generalized minimal residual based iterative back propagation algorithm for polynomial nonlinear models (2021) 153, art. no. 104966, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107070956&doi=10.1016%2fj.sysconle.2021.104966&partnerID=40&md5=19c5e4b5166e5546fdb88084db3e6b58 DOI: 10.1016/j.sysconle.2021.104966 AFFILIATIONS: School of Science, Jiangnan University, Wuxi, 214122, China; Science and Technology on Near-Surface Detection Laboratory, Wuxi, 214028, China; Department of Engineering Design and Mathematics, University of the West of England, Bristol, BS16 1QY, United Kingdom ABSTRACT: In this paper, a back propagation algorithm is proposed for polynomial nonlinear models using generalized minimal residual method. This algorithm, based on Arnoldi's method, can be regarded as a modified gradient descent iterative algorithm, and provides several advantages over the traditional gradient descent iterative algorithm: (1) has less computational efforts for systems with missing data/large-scale systems; (2) does not require the eigenvalue calculation in step-length design; (3) adaptively computes the step-length in each iteration. Therefore, it can be employed for large-scale system identification. The feasibility and effectiveness of the proposed algorithm are established in theory and demonstrated by two simulation examples. © 2021 Elsevier B.V. Lanza, L. Internal dynamics of multibody systems (2021) 152, art. no. 104931, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104570021&doi=10.1016%2fj.sysconle.2021.104931&partnerID=40&md5=73c6e66b45e1b5d83d4451b1b8f1db8f DOI: 10.1016/j.sysconle.2021.104931 AFFILIATIONS: Institut für Mathematik, Universität Paderborn, Warburger Str. 100, Paderborn, 33098, Germany ABSTRACT: We consider nonlinear multibody systems and present a suitable set of coordinates for the internal dynamics which allow to decouple the internal dynamics without the need to compute the Byrnes–Isidori form. Furthermore, we derive sufficient conditions for the system parameters such that the internal dynamics of a class of systems with constant mass matrix are bounded-input, bounded-output stable. © 2021 Elsevier B.V. Jaiswal, J., Gupta, M.K., Tomar, N.K. Necessary and sufficient conditions for ODE observer design of descriptor systems (2021) 151, art. no. 104916, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104159426&doi=10.1016%2fj.sysconle.2021.104916&partnerID=40&md5=02d281bdac1d2306cb152c8e935b4f99 DOI: 10.1016/j.sysconle.2021.104916 AFFILIATIONS: Department of Mathematics, Indian Institute of Technology Patna, India; Department of Mathematics, National Institute of Technology Jamshedpur, India ABSTRACT: This paper studies the existence conditions for the observer design of general linear time-invariant descriptor systems. A necessary and sufficient condition is established in terms of a simple rank criterion involving system coefficient matrices. The asymptotic observer is realized by using a dynamical system described by ordinary differential equations (ODEs). The developed test condition is more accessible to implement than the other two existing works. Numerical examples are provided to demonstrate the effectiveness of the theoretical results obtained. © 2021 Elsevier B.V. Zhang, X., Xue, W., Chen, S., Fang, H. Generalized observability analysis and observer design for a class of systems with multiple uncertain dynamics and measurement biases (2021) 150, art. no. 104897, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102087601&doi=10.1016%2fj.sysconle.2021.104897&partnerID=40&md5=4233357f5666a8372a5c2e561a7ed5f4 DOI: 10.1016/j.sysconle.2021.104897 AFFILIATIONS: LSC, NCMIS, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China; School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China; School of Mathematics and Information Science, Shaanxi Normal University, Xi'an, 710119, China ABSTRACT: This paper is concerned with a systematic discussion on the problem of state estimation for a class of systems with multiple uncertain dynamics and multiple measurement biases. Instead of the traditional observability definition only for system state vector, we consider the generalized observability for the combinations of system state vector, uncertain dynamics and measurement bias. Firstly, a necessary and sufficient condition for the observability of system state vector is developed. Moreover, the set of all the observable combinations of system state vector, uncertain dynamics and measurement bias is presented. Correspondingly, an observer is constructed for estimating a special observable combination which is an approximation of system state vector. More importantly, the bound of the resulting estimation error for the system state vector is quantitatively discussed. Finally, the simulation study on a two-mass–spring system illustrates our theoretical results. © 2021 Elsevier B.V. Shi, L., Zheng, R., Liu, M., Zhang, S. Distributed circumnavigation control of autonomous underwater vehicles based on local information (2021) 148, art. no. 104873, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099887223&doi=10.1016%2fj.sysconle.2021.104873&partnerID=40&md5=06116439abf0aa0fada24fcd4ba36ae3 DOI: 10.1016/j.sysconle.2021.104873 AFFILIATIONS: College of Electrical Engineering, Zhejiang University, China; State Key Laboratory of Industrial Control Technology, Zhejiang University, China ABSTRACT: This paper investigates the distributed circumnavigation problem by an autonomous underwater vehicle (AUV) team to enclose a target. When the AUVs do not have a global coordinate system or a common reference direction, moreover when some vehicles cannot detect the target, this circumnavigation problem becomes challenging. The above situation is common in underwater environments and is taken into account in this paper. Considering the kinematic and dynamic models of vehicles, this paper proposes a cascade-based distributed control law. The proposed control law via local relative position measurement can realize a desired circumnavigation formation around the target. Furthermore, we show that with a radius determinant mechanism, this control law enables the vehicles which do not detect the target to keep a specified pattern without exchanging the target position information. Finally, simulations are provided to illustrate the result. © 2021 Elsevier B.V. Breiten, T., Kunisch, K. Neural network based nonlinear observers (2021) 148, art. no. 104829, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098661950&doi=10.1016%2fj.sysconle.2020.104829&partnerID=40&md5=4d7859e42ebf2f99e4a466066dbb3201 DOI: 10.1016/j.sysconle.2020.104829 AFFILIATIONS: Institute of Mathematics, Technical University of Berlin, Germany; Institute of Mathematics, University of Graz, Austria; RICAM Institute, Austrian Academy of Sciences, Linz, Austria ABSTRACT: Nonlinear observers based on the well-known concept of minimum energy estimation are discussed. The approach relies on an output injection operator determined by a Hamilton–Jacobi–Bellman equation whose solution is subsequently approximated by a neural network. A suitable optimization problem allowing to learn the network parameters is proposed and numerically investigated for linear and nonlinear oscillators. © 2020 Elsevier B.V. Ramos, G., Silvestre, D., Silvestre, C. Node and network resistance to bribery in multi-agent systems (2021) 147, art. no. 104842, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097579886&doi=10.1016%2fj.sysconle.2020.104842&partnerID=40&md5=eb565225517cf79e59bc069b6e95fbca DOI: 10.1016/j.sysconle.2020.104842 AFFILIATIONS: Department of Electrical and Computer Engineering, Faculty of Engineering, University of Porto, Portugal; Department of Electrical and Computer Engineering, Faculty of Science and Technology, University of Macau, China; Institute for Systems and Robotics, Instituto Superior Técnico, University of Lisbon, Portugal ABSTRACT: In this paper, we propose a framework to study the resistance to bribery of nodes in a network via average consensus. We extend the proposed bribery resistance measure to sets of nodes, and networks. The proposed framework evaluates quantitatively how much an external entity needs to drive the state of an agent away from its current state, to change the final consensus value. Subsequently, we illustrate our framework with a set of examples, namely: i) how we can use it to compute the bribing resistance of each node in a network; ii) comparing our measure against metrics from the literature in measuring network bribing resistance; iii) how we may utilize the proposed framework to evaluate the bribing resistance of clusters/groups of nodes in large-scale networks. © 2020 Elsevier B.V. Thuan, D.D., Son, N.H., Tinh, C.T. Stability radii of differential–algebraic equations with respect to stochastic perturbations (2021) 147, art. no. 104834, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097330749&doi=10.1016%2fj.sysconle.2020.104834&partnerID=40&md5=dd872510d917a58bc540b48e4d7fb04d DOI: 10.1016/j.sysconle.2020.104834 AFFILIATIONS: School of Applied Mathematics and Informatics, Hanoi University for Science and Technology, Hanoi, Viet Nam; Faculty of Natural Science, Tran Quoc Tuan University, Son Tay, Hanoi, Viet Nam; Faculty of Mathematics, Mechanics and Informatics, VNU University of Science, Vietnam National University, Hanoi, Viet Nam; Department of Mathematics, University of Information Technology, Ho Chi Minh City, Viet Nam; Vietnam National University, Ho Chi Minh City, Viet Nam ABSTRACT: In this paper, we investigate differential–algebraic equations (DAEs) subject to stochastic perturbations. We introduce the index-ν concept and establish a formula of solution for these equations. After that the stability is studied by using the method of Lyapunov functions. Finally, the robust stability of DAEs with respect to stochastic perturbations is considered. Formulas of the stability radii are derived. An example is given to illustrate the obtained results. © 2020 Elsevier B.V. Boulouz, A., Bounit, H., Hadd, S. Well-posedness and exponential stability of boundary control systems with dynamic boundary conditions (2021) 147, art. no. 104825, . Cited 3 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096821859&doi=10.1016%2fj.sysconle.2020.104825&partnerID=40&md5=1d425734bd9424ab681b080897cd42ab DOI: 10.1016/j.sysconle.2020.104825 AFFILIATIONS: Department of Mathematics, Faculty of Sciences, Ibn Zohr University, Hay Dakhla, Agadir 80000, Morocco ABSTRACT: The well-posedness of abstract boundary control systems with dynamic boundary conditions (i.e., boundary conditions evolving according to an operator semigroup acting on the boundary space) is established. Here, the boundary feedback operator is unbounded which makes the investigation more interesting in many applications. The positivity of such problem is well studied. By exploiting the positivity, we find a characterization of exponential stability. Our approach is based on the feedback theory of infinite dimensional linear systems. Finally, these results are applied to coupled systems consisting of a partial differential equation (PDE) and an ordinary differential equation (ODE) and to diffusion processes in networks with dynamic ramification nodes. © 2020 Elsevier B.V. Ngoc, P.H.A., Tran, K.Q. On stability of solutions of stochastic delay differential equations (2022) 169, art. no. 105384, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139330701&doi=10.1016%2fj.sysconle.2022.105384&partnerID=40&md5=b6c6cccdb28a4f777b415d67b4afde15 DOI: 10.1016/j.sysconle.2022.105384 AFFILIATIONS: Department of Mathematics, Vietnam National University-Ho Chi Minh City, International University, Sai Gon, Viet Nam; Department of Applied Mathematics and Statistics, State University of New York, Korea Campus, Yeonsu-Gu, Incheon, 21985, South Korea ABSTRACT: This paper addresses exponential stability of a class of stochastic delay differential equations and their numerical solutions. We begin by establishing criteria for exponential stability in mean square of stochastic delay differential equations. We then show that the Euler–Maruyama approximation method correctly reproduces exponential stability in mean square for sufficiently small step sizes. Consequently criteria for almost sure exponential stability of the exact and the Euler–Maruyama approximation are also obtained. In contrast to the advances in the literature, this work provides more accurate estimates of the Lyapunov exponents of stochastic delay differential equations and their Euler–Maruyama approximations. © 2022 Elsevier B.V. Zhou, L., Zheng, Y., Zhao, Q., Xiao, F., Zhang, Y. Game-based coordination control of multi-agent systems (2022) 169, art. no. 105376, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138076791&doi=10.1016%2fj.sysconle.2022.105376&partnerID=40&md5=51486837133246d119a9022078884d88 DOI: 10.1016/j.sysconle.2022.105376 AFFILIATIONS: Shaanxi Key Laboratory of Space Solar Power Station System, School of Mechano-electronic Engineering, Xidian University, Xi'an, 710071, China; School of Control and Computer Engineering, North China Electric Power University, Beijing, 102206, China ABSTRACT: In this paper, we are interested in how agents interact with each other in multi-agent systems. First, we model the interactions among agents in multi-agent systems as a multi-player game. The topology of the interactions among agents is a directed graph. We design cost functions for the game and assume that each agent in the systems tends to minimize its own cost. Then, the unique Nash equilibrium solution to the proposed multi-player game is obtained as the next state of the agent. A necessary and sufficient condition for achieving multi-agent consensus is established using the system transformation method and graph theory. Furthermore, we extend the result to the problem of containment control in the presence of leaders. The criterion for solving the containment control is also given in this paper. Finally, several simulation examples are given to verify the effectiveness of the theoretical results. © 2022 Elsevier B.V. Min, X., Baldi, S., Yu, W., Cao, J. Funnel asymptotic tracking of nonlinear multi-agent systems with unmatched uncertainties (2022) 167, art. no. 105313, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134402468&doi=10.1016%2fj.sysconle.2022.105313&partnerID=40&md5=8f6d6b1f157f2c9e2f84e8345713e9a2 DOI: 10.1016/j.sysconle.2022.105313 AFFILIATIONS: School of Mathematics, Southeast University, Nanjing, 210096, China; School of Cyber Science and Engineering, Southeast University, Nanjing, 210096, China; Yonsei Frontier Lab, Yonsei University, Seoul, 03722, South Korea ABSTRACT: This work investigates the asymptotic consensus tracking for high-order uncertain nonlinear multi-agent systems (MASs), in the presence of pre-specified funnel constraints, unmatched uncertainties and possibly discontinuous dynamics. A new distributed discontinuous funnel controller is constructed to ensure asymptotic convergence of the consensus errors with satisfaction of the funnel boundary. The controller is analyzed using non-smooth analysis. The presented solution extends funnel control results proposed in the literature beyond the matched uncertainties and the first/second-order dynamics cases. A numerical study finally illustrates the method. © 2022 Yan, Z., Zhong, S., He, S. Finite-time H2/H∞ control for linear Itô stochastic Markovian jump systems with Brownian motion and Poisson jumps (2022) 165, art. no. 105285, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131458250&doi=10.1016%2fj.sysconle.2022.105285&partnerID=40&md5=786297d138a5d70be7b5476439e43f5f DOI: 10.1016/j.sysconle.2022.105285 AFFILIATIONS: School of Electrical Engineering and Automation, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China; College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao, 266590, China; Key Laboratory of Intelligent Computing and Signal Processing (Ministry of Education), School of Electrical Engineering and Automation, Anhui University, Hefei, 230601, China ABSTRACT: This paper is concerned with the problems of finite-time H2/H∞ control for linear stochastic Markovian jump systems (SMJSs) suffered from external disturbance and both Brownian motion and Poisson jumps. First, with the help of operator spectrum, a necessary and sufficient condition is given for the exact observability of SJMSs with Brownian motion and Poisson jumps, which is utilized to design observer-based controller. Second, a new differential inequality is constructed and the mode-dependent parameter approach (MDPA) is adopted, to obtain some less conservative results for the existence of state feedback and observer-based feedback finite-time H2/H∞ controllers. Compared with the common parameter approach, the advantages of MDPA are clearly shown. Moreover, H2 cost function under observer-based feedback proposed in this paper further considers the estimation errors on the basis of the states and estimations, which is more accurate than previous H2 cost function. Third, two new design algorithms are proposed. One is to search the ranges of some design parameters, and the other is to show the relationship between H2 and H∞ performance indices. Finally, a detailed design example is given to illustrate the merits of the proposed results. © 2022 Elsevier B.V. Liu, D., Tang, M., Fu, J. Robust adaptive trajectory tracking for wheeled mobile robots based on Gaussian process regression (2022) 163, art. no. 105210, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85128207915&doi=10.1016%2fj.sysconle.2022.105210&partnerID=40&md5=a68871f3614fe8094a45fd75f1dcfb47 DOI: 10.1016/j.sysconle.2022.105210 AFFILIATIONS: The School of Mathematics, Southeast University, Nanjing, 210096, China; Purple Mountain Laboratories, Nanjing, 211111, China ABSTRACT: In this paper, we propose a novel learning-based robust adaptive trajectory tracking controller for wheeled mobile robots (WMR) subject to velocity input uncertainties. Gaussian process regression (GPR) is employed in view of its powerful estimation ability and wide scope of applications as a nonparametric regression method. The velocity uncertainties are estimated online using the real-time measured data. The prediction mean and variance of the GPR are used to counteract the effect of the uncertainties and to design the robust control term, respectively. A continuous robust controller is proposed which has the advantage of achieving asymptotic convergence of the trajectory tracking error instead of uniformly ultimately boundedness. Comparisons with the neural network based adaptive controller and a state of the art GPR-based design demonstrate the effectiveness of the proposed control strategy. © 2022 Elsevier B.V. Agram, N., Hu, Y., Øksendal, B. Mean-field backward stochastic differential equations and applications (2022) 162, art. no. 105196, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126959192&doi=10.1016%2fj.sysconle.2022.105196&partnerID=40&md5=40f185df177ab6400fba469c8f24c9ee DOI: 10.1016/j.sysconle.2022.105196 AFFILIATIONS: Department of Mathematics, KTH Royal Institute of Technology 100 44, Stockholm, Sweden; Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, T6G 2G1, Canada; Department of Mathematics, University of Oslo, P.O. Box 1053, BlindernOslo, N–0316, Norway ABSTRACT: In this paper we study the linear mean-field backward stochastic differential equations (mean-field BSDE) of the form dY(t)=−[α1(t)Y(t)+β1(t)Z(t)+∫R0η1(t,ζ)K(t,ζ)ν(dζ)+α2(t)E[Y(t)]+β2(t)E[Z(t)]+∫R0η2(t,ζ)E[K(t,ζ)]ν(dζ)+γ(t)]dt+Z(t)dB(t)+∫R0K(t,ζ)Ñ(dt,dζ),t∈0,T,Y(T)=ξ.where (Y,Z,K) is the unknown solution triplet, B is a Brownian motion, Ñ is a compensated Poisson random measure, independent of B. We prove the existence and uniqueness of the solution triplet (Y,Z,K) of such systems. Then we give an explicit formula for the first component Y(t) by using partial Malliavin derivatives. To illustrate our result we apply them to study a mean-field recursive utility optimization problem in finance. © 2022 The Author(s) Chaffey, T. A rolled-off passivity theorem (2022) 162, art. no. 105198, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126539511&doi=10.1016%2fj.sysconle.2022.105198&partnerID=40&md5=41da226995b8f529d46b43c902ca585f DOI: 10.1016/j.sysconle.2022.105198 AFFILIATIONS: University of Cambridge, Department of Engineering, Trumpington Street, Cambridge, CB2 1PZ, United Kingdom ABSTRACT: Given two nonlinear systems which only violate incremental passivity when their incremental gains are sufficiently small, we give a condition for their negative feedback interconnection to have finite incremental gain, which generalizes the incremental small gain and incremental passivity theorems. The property may be determined graphically by plotting the Scaled Relative Graphs (SRGs) of the systems, which provides engineering significance to the mathematical result. © 2022 Elsevier B.V. Ruiz-Balet, D., Affili, E., Zuazua, E. Interpolation and approximation via Momentum ResNets and Neural ODEs (2022) 162, art. no. 105182, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126115862&doi=10.1016%2fj.sysconle.2022.105182&partnerID=40&md5=3c02d13be161ac69809afa4a6398ceac DOI: 10.1016/j.sysconle.2022.105182 AFFILIATIONS: Chair of Computational Mathematics, Fundación Deusto Av. de las Universidades 24, Bilbao, Basque Country, 48007, Spain; Departamento de Matemáticas, Universidad Autónoma de Madrid, Madrid, 28049, Spain; Chair in Applied Analysis, Alexander von Humboldt-Professorship, Department of Data Science Friedrich-Alexander-Universität, Erlangen-Nürnberg, Erlangen, 91058, Germany; Department of Mathematics, Imperial College London, London, SW7 2AZ, United Kingdom ABSTRACT: In this article, we explore the effects of memory terms in continuous-layer Deep Residual Networks by studying Neural ODEs (NODEs). We investigate two types of models. On one side, we consider the case of Residual Neural Networks with dependence on multiple layers, more precisely Momentum ResNets. On the other side, we analyse a Neural ODE with auxiliary states playing the role of memory states. We examine the interpolation and universal approximation properties for both architectures through a simultaneous control perspective. We also prove the ability of the second model to represent sophisticated maps, such as parametrizations of time-dependent functions. Numerical simulations complement our study. © 2022 Elsevier B.V. Liu, P., Xiao, F., Wei, B., Yu, M. Nash equilibrium seeking for individual linear dynamics subject to limited communication resources (2022) 161, art. no. 105162, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125016643&doi=10.1016%2fj.sysconle.2022.105162&partnerID=40&md5=813afbd32741ba2a7f638e9d729167a6 DOI: 10.1016/j.sysconle.2022.105162 AFFILIATIONS: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206, China; School of Control and Computer Engineering, North China Electric Power University, Beijing, 102206, China ABSTRACT: In this paper, non-cooperative game problems with individual linear dynamics of players are addressed. In the case of limited communication resources, event-triggering mechanisms equip players to determine event instants. A period of dwell time is enforced after each event. In the dwell time, monitoring event-triggering conditions is avoided for each player, which saves resources. After the dwell time, each player triggers the broadcast to its neighbors once a fully distributed event-triggering condition is satisfied. Along this line, the Zeno behavior is excluded. The proposed control algorithm with discrete-time communications converges the systems to an NE. The effectiveness of the proposed control algorithms and event-triggering mechanisms is demonstrated through simulations. © 2022 Elsevier B.V. Casini, M., Garulli, A. On the advantage of centralized strategies in the three-pursuer single-evader game (2022) 160, art. no. 105122, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122611244&doi=10.1016%2fj.sysconle.2021.105122&partnerID=40&md5=3fb64ef8b98129dcf7eb4ad88184a48a DOI: 10.1016/j.sysconle.2021.105122 AFFILIATIONS: Dipartimento di Ingegneria dell'Informazione e Scienze Matematiche, Università di Siena, Via Roma 56, Siena, 53100, Italy ABSTRACT: Cooperation in multi-pursuer games is known to be useful. However, it is not easy to quantify how much it is convenient for the pursuers to play according to a centralized strategy with respect to a decentralized one. This paper provides an answer to this question, for the problem of three pursuers chasing a single evader in a planar environment. It is shown that centralized pursuit algorithms can halve the time required to capture the evader, with respect to decentralized pursuit strategies. Moreover, this limit is proven to be tight. Numerical computations of lower bounds to the ratio between the capture times of centralized and decentralized strategies, show that for several game initial conditions the benefit of playing in a centralized way may be significantly less than halving the game duration. © 2022 Elsevier B.V. Wu, H., Hu, J., Yuan, C. Stability of hybrid pantograph stochastic functional differential equations (2022) 160, art. no. 105105, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121964154&doi=10.1016%2fj.sysconle.2021.105105&partnerID=40&md5=775260eb9ac79d99b9fd871efbd203b1 DOI: 10.1016/j.sysconle.2021.105105 AFFILIATIONS: School of Mathematics and Statistics, South-Central University For Nationalities, Wuhan, Hubei, 430000, China; Department of Mathematics, Swansea University, Bay CampusUK SA1 8EN, United Kingdom ABSTRACT: In this paper, we study a new type of stochastic functional differential equations which are called hybrid pantograph stochastic functional differential equations (HPSFDEs). We investigate moment properties and sample properties of the solutions such as the moment exponential stability, almost sure exponential stability and almost sure polynomial stability. Moreover, several theoretical examples and one practical example are given to illustrate our theory. © 2021 Elsevier B.V. Guan, K., Luo, R. Finite-time stability of impulsive pantograph systems with applications (2021) 157, art. no. 105054, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117216562&doi=10.1016%2fj.sysconle.2021.105054&partnerID=40&md5=e4731473948a093307dc17ae98f4a2fb DOI: 10.1016/j.sysconle.2021.105054 AFFILIATIONS: School of Mathematics and Computational Science, Wuyi University, Jiangmen, Guangdong, 529020, China ABSTRACT: This paper is mainly concerned with the finite-time stability of impulsive pantograph systems. By proposing a novel Razumikhin condition, and combining Lyapunov-Razumikhin method with average impulsive interval approach, we derive some criteria to ensure that the addressed impulsive pantograph systems are finite-time stable. Also, based on this Razumikhin condition, new Lyapunov-based conditions are obtained for the finite-time stability and the global power stability of nonlinear pantograph systems. The validity of our results is finally illustrated by three examples. © 2021 Elsevier B.V. Pradhan, S. Risk-sensitive zero-sum stochastic differential game for jump–diffusions (2021) 157, art. no. 105033, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115887226&doi=10.1016%2fj.sysconle.2021.105033&partnerID=40&md5=b1002257f94ae43e4c051ac2d4fc669d DOI: 10.1016/j.sysconle.2021.105033 AFFILIATIONS: Department of Mathematics, Indian Institute of Science Education and Research, Dr. Homi Bhabha Road, Pune, 411008, India ABSTRACT: This article is concerned with the infinite horizon risk-sensitive zero-sum stochastic differential game problem for a class of jump–diffusions controlled through the drift, and driven by a compensated Poisson process and a Wiener process. Under certain geometric stability assumption on the dynamics, we completely characterize all possible saddle point strategies in the class of stationary Markov strategies. We obtain our result by exploiting the stochastic representation of the principal eigenfunction of the associated Hamilton–Jacobi–Isaac (HJI) equation, which is a semilinear integro-partial differential equation. © 2021 Elsevier B.V. Hamdipoor, V., Moon, J., Kim, Y. Stability margin of undirected homogeneous relative sensing networks: A geometric perspective (2021) 156, art. no. 105027, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114128041&doi=10.1016%2fj.sysconle.2021.105027&partnerID=40&md5=f7be2db12f7758bbb6da15a86ea02b27 DOI: 10.1016/j.sysconle.2021.105027 AFFILIATIONS: Graduate School of Mechanical and Aerospace Engineering, Gyeongsang National University, Jinju, 52828, South Korea; School of Electrical Engineering, Hanyang University, Seoul, 04763, South Korea ABSTRACT: In this paper, we study the stability margin (SM) of undirected homogeneous relative sensing networks (UH-RSNs) from a geometric point of view. SM is an important robustness measure indicating the amount of simultaneous gain and phase perturbations in the feedback channels before the instability occurs. A UH-RSN is characterized by the identical local dynamics (a single-input-single-output (SISO) open-loop transfer function Tloc(s)) of individual agent and the graph Laplacian LG representing how the agents are connected. It is shown in this paper that UH-RSNs having multiple inputs and outputs in general may be represented as a unity feedback system including the SISO Tloc(s) and one of the real eigenvalues of LG. This representation then helps to identify a class of cooperative Tloc(s) for which (1) SM becomes maximized or equal to 1 when the network's connectivity (the second smallest eigenvalue of LG) is greater than or equal to the curvature of the Nyquist plot of Tloc(s) at the origin; and (2) two bounds on SM are obtained for the SM estimation based on the geometric shape of Nyquist plot. Also, the representation of unity feedback system implies that UH-RSNs with non-cooperative Tloc(s) become unstable when the agents are joined with high connectivity. Numerical examples are provided to demonstrate these findings. © 2021 Elsevier B.V. Zhang, J., Kang, W., Fridman, E., Seuret, A. Delayed stabilization of parabolic PDEs via augmented Lyapunov functionals and Legendre polynomials (2021) 156, art. no. 105003, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112405072&doi=10.1016%2fj.sysconle.2021.105003&partnerID=40&md5=6b50ce75130826261949a24a02fa67f6 DOI: 10.1016/j.sysconle.2021.105003 AFFILIATIONS: School of Electrical Engineering, Tel Aviv University, Tel Aviv, 69978, Israel; School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, 100083, China; LAAS-CNRS, Université de Toulouse, CNRS, France ABSTRACT: We first study stabilization of heat equation with globally Lipschitz nonlinearity. We consider the point measurements with constant delay and use spatial decomposition. Inspired by recent developments in the area of ordinary differential equations (ODEs) with time-delays, for the stability analysis, we suggest an augmented Lyapunov functional depending on the state derivative that is based on Legendre polynomials. Global exponential stability conditions are derived in terms of linear matrix inequalities (LMIs) that depend on the degree N of Legendre polynomials. The stability conditions form a hierarchy of LMIs: if the LMIs hold for N, they hold for N+1. The dual observer design problem with constant delay is also formulated. We further consider stabilization of Korteweg–de Vries–Burgers (KdVB) equation using the point measurements with constant delay. Due to the third-order partial derivative in KdVB equation, the Lyapunov functionals that depend on the state derivative are not applicable here, which is different from the case of heat equation. We suggest a novel augmented Lyapunov functional depending on the state only that leads to improved regional stability conditions in terms of LMIs. Finally, numerical examples illustrate the efficiency of the method. © 2021 Elsevier B.V. Oliveira, T.R., Krstic, M. Extremum seeking boundary control for PDE–PDE cascades (2021) 155, art. no. 105004, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112274778&doi=10.1016%2fj.sysconle.2021.105004&partnerID=40&md5=b7e56fcec26bb7646c1490882b0b6087 DOI: 10.1016/j.sysconle.2021.105004 AFFILIATIONS: Department of Electronics and Telecommunication Engineering, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ 20550-900, Brazil; Department of Mechanical and Aerospace Engineering, University of California - San Diego (UCSD), La Jolla, CA 92093-0411, United States ABSTRACT: The goal of this paper is to shed light on new opportunities for extremum seeking through extensions to locally quadratic nonlinear maps with actuator dynamics modeled by cascades of partial differential equations (PDEs). First, we deal with PDEs with input delays such as, for example, the notoriously difficult problem of a wave PDE with input delay where, if the delay is left uncompensated, an arbitrarily short delay destroys the closed-loop stability. Then, we move forward to an even more challenging class of problems for parabolic–hyperbolic cascades of PDEs, coping with a heat equation at the input of a wave PDE. The treatment of such systems with PDE–PDE cascades is performed by means of boundary control. The proposed approach yields (small-gain) loops that make the control design constructive and enables stability analysis with quantitative estimates. Local exponential stability and convergence to a small neighborhood of the unknown extremum point are rigorously guaranteed. This result is achieved by using backstepping transformation and averaging in infinite dimensions. Although we keep the presentation using the classical Gradient extremum seeking, the generalization of the results for the Newton-based approach is also indicated. A numerical example is given to illustrate the effectiveness of the proposed extremum seeking boundary control for compensation of PDE–PDE cascades. © 2021 Elsevier B.V. Aleksandrov, A. A problem of formation control on a line segment under protocols with communication delay (2021) 155, art. no. 104990, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111268337&doi=10.1016%2fj.sysconle.2021.104990&partnerID=40&md5=b2e26b2e90451868f3c50bbdf689460f DOI: 10.1016/j.sysconle.2021.104990 AFFILIATIONS: Quantori, 625 Massachusetts Avenue, Cambridge, 02139, United States ABSTRACT: The problem of the equidistant deployment of a group of mobile agents on a line segment is studied. Both cases where agent dynamics is modeled by the first-order integrators and double integrators are considered. It is assumed that each agent receives information from its neighbors not directly, but via an auxiliary agent. The impact of communication delays on the agent deployment is investigated. Conditions are derived ensuring the convergence of agents to the equidistant distribution for any constant nonnegative delays. Efficiency of the obtained results is demonstrated by a numerical simulation. © 2021 Elsevier B.V. Agram, N., Djehiche, B. On a class of reflected backward stochastic Volterra integral equations and related time-inconsistent optimal stopping problems (2021) 155, art. no. 104989, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85110267391&doi=10.1016%2fj.sysconle.2021.104989&partnerID=40&md5=c8426eb57f2123be9d769490559af942 DOI: 10.1016/j.sysconle.2021.104989 AFFILIATIONS: Department of Mathematics, Linnaeus University (LNU)Växjö, Sweden; Department of Mathematics, KTH Royal Institute of Technology, Stockholm, 100 44, Sweden ABSTRACT: We introduce a class of one-dimensional continuous reflected backward stochastic Volterra integral equations driven by Brownian motion, where the reflection keeps the solution above a given stochastic process (lower obstacle). We prove existence and uniqueness by a fixed point argument and derive a comparison result. Moreover, we show how the solution of our problem is related to a time-inconsistent optimal stopping problem and derive an optimal strategy. © 2021 Elsevier B.V. Millérioux, G., Jungers, R. Characterization of flat outputs of switched linear discrete-time systems: Algebraic condition and algorithm (2021) 154, art. no. 104970, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108002400&doi=10.1016%2fj.sysconle.2021.104970&partnerID=40&md5=bbcdcb4c0c318edf33af77d781438d7f DOI: 10.1016/j.sysconle.2021.104970 AFFILIATIONS: Université de Lorraine, CNRS, CRAN, 2 Rue Jean Lamour, Vandoeuvre-les-Nancy, 54519, France; UCL/ICTEAM, Louvain-la-Neuve, Belgium ABSTRACT: The problem of flat output characterization for switched linear discrete-time systems is addressed. First, an algebraic condition for an output to be flat is provided. It applies for I-flat outputs with the integer I potentially strictly greater than 1. Next, it is proved that such a characterization is decidable. Finally, an efficient algorithm which allows to decide in polynomial time whether a given output is flat is given. The algorithm is built from the observation that the flat output characterization can be expressed in terms of dead-beat stability of an associated constrained switched system. Thus, the notions of joint spectral radius and graph theory play relevant roles in this context. © 2021 Elsevier B.V. Rohou, S., Jaulin, L. Exact bounded-error continuous-time linear state estimator (2021) 153, art. no. 104951, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105332029&doi=10.1016%2fj.sysconle.2021.104951&partnerID=40&md5=2d3383d225917bcd9d114afba34c2fbb DOI: 10.1016/j.sysconle.2021.104951 AFFILIATIONS: ENSTA Bretagne, Lab-STICC, UMR CNRS 6285, Brest, France ABSTRACT: This paper proposes an interval-based method for estimating the state of a linear continuous-time dynamical system. In this work, we assume that the measurements are provided at discrete times and that all errors are bounded. Interval analysis is used to propagate the interval uncertainties continuously over time. The resulting method is guaranteed to never lose any feasible solution and provides an optimal polygonal enclosure of the state trajectory. A reproducible example illustrates the principle of the method. © 2021 Elsevier B.V. Long, L. Synchronous vs asynchronous switching-based output-feedback control for switched nonlinear systems with measurement noise sensitivity (2021) 152, art. no. 104935, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105691970&doi=10.1016%2fj.sysconle.2021.104935&partnerID=40&md5=47170ddc4607a0d5e6c720e599dc9d40 DOI: 10.1016/j.sysconle.2021.104935 AFFILIATIONS: College of Information Science and Engineering, Northeastern University, Shenyang, 110819, China; State Key Laboratory of Synthetical Automation for Process Industries, Northeastern University, Shenyang, 110819, China ABSTRACT: This paper investigates the problem of output-feedback control in the presence of measurement noise sensitivity for a class of switched nonlinear systems with unknown control coefficients under synchronous vs asynchronous switching. A constructive output-feedback control technique is provided by exploiting the dual-domination method and the average dwell time (ADT) method, which permits removal of a common restriction for output-feedback control in which the measurement sensitivity in switched systems is always a known constant. Also, output-feedback controllers of subsystems with a switched linear observer are designed to guarantee asymptotic stability of the closed-loop system under a class of switching signals with ADT, which effectively handle the influence of different sensor sensitivities for different subsystems in both synchronous vs asynchronous switching. Finally, simulation examples, including a mass–spring–damper mechanical system as a practical example, are given to illustrate the effectiveness of the technique proposed. © 2021 Elsevier B.V. Fotiadis, F., Vamvoudakis, K.G. Detection of actuator faults for continuous-time systems with intermittent state feedback (2021) 152, art. no. 104938, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105086763&doi=10.1016%2fj.sysconle.2021.104938&partnerID=40&md5=8d4ce993e7e3ecb9161b6b2b425ea3ca DOI: 10.1016/j.sysconle.2021.104938 AFFILIATIONS: Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States ABSTRACT: This paper considers the problem of detecting actuator faults on uncertain continuous-time systems, where the state can be measured only intermittently. Initially, we describe the class of faults which we want to identify, as those that create a state evolution that is incompatible with the model of the system. We then derive a necessary and sufficient condition, the verification of which allows us to detect the aforementioned inconsistencies. Relaxations are employed to make this verification computationally easier and an equivalent condition, in the ϵ−closeness sense, is obtained, through the solution of a boundary-value problem. We finally present simulation results that showcase the effectiveness of our proposed algorithm, in terms of speed and validity. © 2021 Elsevier B.V. Bonnet, B., Flayac, É. Consensus and flocking under communication failures for a class of Cucker–Smale systems (2021) 152, art. no. 104930, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105076065&doi=10.1016%2fj.sysconle.2021.104930&partnerID=40&md5=61b696ce932f8d898e64602e8fb5c6df DOI: 10.1016/j.sysconle.2021.104930 AFFILIATIONS: Inria Paris & Laboratoire Jacques-Louis Lions, Sorbonne Université, Université Paris-Diderot SPC, CNRS, Inria, Paris, 75005, France; University of Melbourne, Parkville, Melbourne, VIC 3010, Australia ABSTRACT: In this paper, we study sufficient conditions for the emergence of asymptotic consensus and flocking in a certain class of non-linear generalised Cucker–Smale systems subject to multiplicative communication failures. Our approach is based on the combination of strict Lyapunov design together with the formulation of a suitable persistence condition for multi-agent systems. The latter can be interpreted as a lower bound on the algebraic connectivity of the time-average of the interaction graph generated by the communication weights, and provides quantitative decay estimates for the variance functional along the solutions of the system. © 2021 Elsevier B.V. Liu, Y., Ossareh, H.R. Preview Reference Governors: A constraint management technique for systems with preview information (2021) 152, art. no. 104932, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104921024&doi=10.1016%2fj.sysconle.2021.104932&partnerID=40&md5=0579a22fe2923f6576f8174c30912ee6 DOI: 10.1016/j.sysconle.2021.104932 AFFILIATIONS: Department of Electrical and Biomedical Engineering, University of Vermont, Burlington, VT 05405, United States ABSTRACT: This paper presents a constraint management strategy based on Scalar Reference Governors (SRG) to enforce output, state, and control constraints while taking into account the preview information of the reference signal. The strategy, referred to as the Preview Reference Governor (PRG), can outperform SRG while maintaining the highly-attractive computational benefits of SRG. However, as it is shown, the performance of PRG may suffer if large preview horizons are used. An extension of PRG, referred to as Multi-horizon PRG, is proposed to remedy this issue. Quantitative comparisons between SRG, PRG, and Multi-horizon PRG on a one-link robot arm example are presented to illustrate their performance and computation time. Finally, novel extensions of PRG are presented to handle systems with uncertain preview information, systems with disturbance preview, and systems with multiple reference signals. © 2021 Elsevier B.V. PK, M.A., Rayyan Sheriff, M., Chatterjee, D. Measure of quality of finite-dimensional linear systems: A frame-theoretic view (2021) 151, art. no. 104911, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103791841&doi=10.1016%2fj.sysconle.2021.104911&partnerID=40&md5=0143d47c787704362e3318591982b680 DOI: 10.1016/j.sysconle.2021.104911 AFFILIATIONS: Department of Electrical Engineering, University of Illinois at Urbana-Champaign, Champaign, IL, United States; Systems & Control Engineering, IIT Bombay, Powai, Mumbai, 400076, India ABSTRACT: A measure of quality of a control system is a quantitative extension of the classical binary notion of controllability. In this article we study the quality of linear control systems from a frame-theoretic perspective. We demonstrate that all LTI systems naturally generate a frame on their state space, and that three standard measures of quality involving the trace, minimum eigenvalue, and the determinant of the controllability Gramian achieve their optimum values when this generated frame is tight. Motivated by this, and in view of some recent developments in frame-theoretic signal processing, we propose a natural measure of quality for continuous time LTI systems based on a measure of tightness of the frame generated by it and then discuss some properties of this frame-theoretic measure of quality. © 2021 Elsevier B.V. Barreau, M., Tarbouriech, S., Gouaisbaut, F. Lyapunov stability analysis of a mass–spring system subject to friction (2021) 150, art. no. 104910, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103316113&doi=10.1016%2fj.sysconle.2021.104910&partnerID=40&md5=299376e20dfe7bf22a02b1f097ba0b50 DOI: 10.1016/j.sysconle.2021.104910 AFFILIATIONS: Division of Decision and Control Systems, KTH Royal Institute of Technology Stockholm, Sweden; LAAS-CNRS, Université de Toulouse, CNRS, UPS, Toulouse, France ABSTRACT: This paper deals with the stability analysis of a mass–spring system subject to friction using Lyapunov-based arguments. As the described system presents a stick–slip phenomenon, the mass may then periodically stick to the ground. The objective consists of developing numerically tractable conditions ensuring the global asymptotic stability of the unique equilibrium point. The proposed approach merges two intermediate results: The first one relies on the characterization of an attractor around the origin, to which converges the closed-loop trajectories. The second result assesses the regional asymptotic stability of the equilibrium point by estimating its basin of attraction. The main result relies on conditions allowing to ensure that the attractor issued from the first result is included in the basin of attraction of the origin computed from the second result. An illustrative example draws the interest of the approach. © 2021 The Authors Pei, W., Xi, Y., Hu, Y., Yan, L. Active disturbance rejection control approach to output-feedback stabilization of nonlinear system with Lévy noises (2021) 150, art. no. 104898, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101961167&doi=10.1016%2fj.sysconle.2021.104898&partnerID=40&md5=cc65d5221d6b34235a59f960443adfec DOI: 10.1016/j.sysconle.2021.104898 AFFILIATIONS: College of Information Science and Technology, Donghua University, Shanghai, China; School of Mathematical Sciences, Nankai University, Tianjin, China; Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, Canada; Department of Statistics, Donghua University, Shanghai, China ABSTRACT: In this paper, the active disturbance rejection control (ADRC) approach, an emerging control approach, is applied to output-feedback stabilization for uncertain nonlinear systems disturbed by external stochastic disturbance. Here the disturbance has the form of an uncertain system driven by both Brownian motion and Lévy noises. Firstly, for the sake of estimation for all the states and stochastic disturbance, an efficient extended state observer (ESO) is designed. Then an ESO-based output-feedback control approach and the stability in the mean squared sense are finally developed, respectively. A numerical simulation is also presented to demonstrate the effectiveness of our approach. © 2021 Elsevier B.V. Rokhforoz, P., Kebriaei, H., Ahmadabadi, M.N. Large-scale dynamic system optimization using dual decomposition method with approximate dynamic programming (2021) 150, art. no. 104894, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101630039&doi=10.1016%2fj.sysconle.2021.104894&partnerID=40&md5=247f234db33f09333f8dc7807bfd2a7d DOI: 10.1016/j.sysconle.2021.104894 AFFILIATIONS: School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran; School of Computer Science, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5746, Tehran, Iran ABSTRACT: In this paper, multi-agent dynamic optimization with a coupling constraint is studied. The aim is to minimize a strongly convex social cost function, by considering a linear stochastic dynamics for each agent and also coupling constraints among the agents. In order to handle the coupling constraint and also, to avoid high computational cost imposed by a centralized method for large scale systems, the dual decomposition method is used to decompose the problem into multiple individual sub-problems, while the dual variable is adjusted by a coordinator. Nevertheless, since each sub-problem is not a linear–quadratic (LQ) optimal control problem, and hence its closed-form solution does not exist, approximate dynamic programming (ADP) is utilized to solve the sub-problems. The main contribution of the paper is to propose an algorithm by considering the interrelated iterations of dual variable adjustment and ADP, and to prove the convergence of the algorithm to the global optimal solution of the social cost function. Additionally, the implementation of the proposed algorithm using a neural network is presented. Also, the computational advantage of the proposed algorithm in comparison with other bench-marking methods is discussed in simulation results. © 2021 Elsevier B.V. Barbu, V. Boundary controllability of phase-transition region of a two-phase Stefan problem (2021) 150, art. no. 104896, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101612495&doi=10.1016%2fj.sysconle.2021.104896&partnerID=40&md5=7ae2b67ea4453744dbb8730e3f21ee8c DOI: 10.1016/j.sysconle.2021.104896 AFFILIATIONS: Octav Mayer Institute of Mathematics of the Romanian Academy and Al.I. Cuza University, Iaşi, Romania ABSTRACT: One proves that the moving interface of a two-phase Stefan problem on Ω⊂Rd, d=1,2,3, is controllable at the end time T by a Neumann boundary controller u. The phase-transition region is a mushy region {σtu;0≤t≤T} of a modified Stefan problem and the main result amounts to saying that, for each Lebesgue measurable set Ω∗ with positive measure, there is u∈L2((0,T)×∂Ω) such that Ω∗⊂σTu. To this aim, one uses an optimal control approach combined with Carleman's inequality and the Kakutani fixed point theorem. © 2021 Elsevier B.V. Xu, Y. Characterization by detectability inequality for periodic stabilization of linear time-periodic evolution systems (2021) 149, art. no. 104871, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099682925&doi=10.1016%2fj.sysconle.2021.104871&partnerID=40&md5=a07f915dec1a9159b3a180d3e61fd08b DOI: 10.1016/j.sysconle.2021.104871 AFFILIATIONS: School of Mathematical Sciences, Fudan University, KLMNS, Shanghai, 200433, China ABSTRACT: Given a linear time-periodic control system in a Hilbert space with a bounded control operator, we present a characterization of periodic stabilization in terms of a detectability inequality. Similar characterization was built up in Trélat et al. (2020), for time-invariant systems. © 2021 Elsevier B.V. Hayat, A. Global exponential stability and Input-to-State Stability of semilinear hyperbolic systems for the L2 norm (2021) 148, art. no. 104848, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098141069&doi=10.1016%2fj.sysconle.2020.104848&partnerID=40&md5=48c420b678c8970e3263bae8a150ef76 DOI: 10.1016/j.sysconle.2020.104848 AFFILIATIONS: CERMICS, Ecole des Ponts ParisTech, 6-8 Avenue Blaise PascalChamps-sur-Marne, France; Department of Mathematical Sciences and Center for Computational and Integrative Biology, Rutgers University–Camden, 303 Cooper St, Camden, NJ, United States ABSTRACT: In this paper we study the global exponential stability in the L2 norm of semilinear 1-d hyperbolic systems on a bounded domain, when the source term and the nonlinear boundary conditions are Lipschitz. We exhibit two sufficient stability conditions: an internal condition and a boundary condition. This result holds also when the source term is nonlocal. Finally, we show its robustness by extending it to global Input-to State Stability in the L2 norm with respect to both interior and boundary disturbances. © 2020 Elsevier B.V. Zhuk, S., Iftime, O.V., Epperlein, J.P., Polyakov, A. Minimax sliding mode control design for linear evolution equations with noisy measurements and uncertain inputs (2021) 147, art. no. 104830, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097584396&doi=10.1016%2fj.sysconle.2020.104830&partnerID=40&md5=be85a3992b603935fde9e09e699a9a5e DOI: 10.1016/j.sysconle.2020.104830 AFFILIATIONS: IBM Research, IBM Technology Campus, Damastown, Dublin, Ireland; Department of Econometrics, Economics and Finance, University of Groningen, Nettelbosje 2, Groningen, 9747 AE, Netherlands; Inria Lille-Nord Europe, 40 av. Halley, Villeneuve d'Ascq50650, France ABSTRACT: We extend a sliding mode control methodology to linear evolution equations with uncertain but bounded inputs and noise in observations. We first describe the reachability set of the state equation in the form of an infinite-dimensional ellipsoid, and then steer the minimax center of this ellipsoid toward a finite-dimensional sliding surface in finite time by using the standard sliding mode output-feedback controller in equivalent form. We demonstrate that the designed controller is the best (in the minimax sense) in the class of all measurable functionals of the output. Our design is illustrated by two numerical examples: output-feedback stabilization of linear delay equations, and control of moments for an advection–diffusion equation in 2D. © 2020 Elsevier B.V. Lewkowicz, I. Passive linear continuous-time systems: Characterization through structure (2021) 147, art. no. 104816, . Cited 2 times. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096843239&doi=10.1016%2fj.sysconle.2020.104816&partnerID=40&md5=3ce4505d99c28f1d0373ba48834637aa DOI: 10.1016/j.sysconle.2020.104816 AFFILIATIONS: School of Electrical and Computer Engineering Ben-Gurion University of the Negev, P.O.B. 653, Beer-Sheva84105, Israel ABSTRACT: We here show that the family of finite-dimensional, continuous-time, passive, linear, time-invariant systems can be characterized through the structure of maximal matrix-convex cones, closed under inversion. Moreover, this observation unifies three setups: (i) differential inclusions, (ii) matrix-valued rational functions, (iii) realization arrays associated with rational functions. It turns out that in the discrete-time case, the corresponding structure is of a maximal matrix-convex set, closed under multiplication among its elements. © 2020 Elsevier B.V. Joshi, A.A., Taghvaei, A., Mehta, P.G., Meyn, S.P. Controlled interacting particle algorithms for simulation-based reinforcement learning (2022) 170, art. no. 105392, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141917983&doi=10.1016%2fj.sysconle.2022.105392&partnerID=40&md5=d1fb5b91b853e5681fa7bbd401fc37dc DOI: 10.1016/j.sysconle.2022.105392 AFFILIATIONS: Coordinated Science Laboratory and the Department of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign, United States; William E. Boeing Department of Aeronautics and Astronautics at University of Washington Seattle, United States; Department of Electrical and Computer Engineering at University of Florida, Gainesville, United States ABSTRACT: This paper is concerned with optimal control problems for control systems in continuous time, and interacting particle system methods designed to construct approximate control solutions. Particular attention is given to the linear quadratic (LQ) control problem. There is a growing interest in re-visiting this classical problem, in part due to the successes of reinforcement learning (RL). The main question of this body of research (and also of our paper) is to approximate the optimal control law without explicitly solving the Riccati equation. A novel simulation-based algorithm, namely a dual ensemble Kalman filter (EnKF), is introduced. The algorithm is used to obtain formulae for optimal control, expressed entirely in terms of the EnKF particles. An extension to the nonlinear case is also presented. The theoretical results and algorithms are illustrated with numerical experiments. © 2022 Elsevier B.V. Cai, X., Xiao, F., Wei, B. Distributed strategy-updating rules for aggregative games of multi-integrator systems with coupled constraints (2022) 170, art. no. 105401, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141462812&doi=10.1016%2fj.sysconle.2022.105401&partnerID=40&md5=7a656b6024bd7e42cc0987e55c47bf85 DOI: 10.1016/j.sysconle.2022.105401 AFFILIATIONS: State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Beijing, 102206, China; School of Control and Computer Engineering, North China Electric Power University, Beijing, 102206, China; School of Electrical Engineering, Xinjiang University, Urumqi, 830047, China ABSTRACT: Inspired by the observation that in many practical engineering scenarios in which aggregative games have been applied, agents not only have inherent complex dynamics but also their strategies are limited by local and coupled constraints, this paper considers the design of a distributed method for multi-integrator agents to seek the generalized Nash equilibrium of a class of aggregative games. First, an aggregative game over a network of multi-integrator agents with both local and coupled constraints is formulated. A distributed strategy-updating rule is proposed for multi-integrator agents by a combination of the state feedback, the output feedback, the coordination of Lagrange multipliers and the estimation of the aggregator. To deal with local constraints, the projected output feedback is utilized to overcome the difficulty that the projected dynamics are invalid for high-order dynamic systems. The effectiveness of the proposed strategy-updating rule is demonstrated by analyzing the convergence of corresponding dynamical system via the Lyapunov stability theory and the singular perturbation theory. Numerical examples are given to illustrate our results. © 2022 Elsevier B.V. Deori, R., Kulkarni, A.A. Information revelation through signalling (2022) 169, art. no. 105378, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139593549&doi=10.1016%2fj.sysconle.2022.105378&partnerID=40&md5=e1f14e0ae1d163d0a34ba8cbac7b325c DOI: 10.1016/j.sysconle.2022.105378 AFFILIATIONS: Systems and Control Engineering, Indian Institute of Technology Bombay, Powai, Maharashtra, Mumbai, 400076, India ABSTRACT: This paper studies a Stackelberg game wherein a sender (leader) attempts to shape the information of a less informed receiver (follower) who in turn takes an action that determines the payoff for both players. The sender chooses signals to maximize its own utility function while the receiver aims to ascertain the value of a source that is privately known to the sender. It is well known that such sender–receiver games admit a vast number of equilibria and not all signals from the sender can be relied on as truthful. Our main contribution is an exact characterization of the minimum number of distinct source symbols that can be correctly recovered by a receiver in any equilibrium of this game; we call this quantity the informativeness of the sender. We show that the informativeness is given by the vertex clique cover number of a certain graph induced by the utility function, whereby it can be computed based on the utility function alone without the need to enumerate all equilibria. We find that informativeness characterizes the existence of well-known classes of separating, pooling and semi-separating equilibria. We also compare informativeness with the amount of information obtained by the receiver when it is the leader and show that the informativeness is always greater than the latter, implying that the receiver is better off being a follower. Additionally, we also show that when the players play behavioural strategies, an equilibrium may not exist. © 2022 Elsevier B.V. Ramos, G., Silvestre, D., Aguiar, A.P. A resilient continuous-time consensus method using a switching topology (2022) 169, art. no. 105381, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138811222&doi=10.1016%2fj.sysconle.2022.105381&partnerID=40&md5=7bd7d877976c8198b8a5789526ac6c48 DOI: 10.1016/j.sysconle.2022.105381 AFFILIATIONS: Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal; LASIGE, Departamento de LASIGE, Departamento de Informática, Faculdade de Ciências, Universidade de Lisboa, Portugal; COPELABS, University Lusófona, Portugal; Department of Electrical and Computer Engineering, Faculty of Sciences and Technology, NOVA University of Lisbon, Portugal; Department of Electrical and Computer Engineering, Faculty of Engineering, University of Porto, Portugal ABSTRACT: This paper addresses the design problem of a resilient consensus algorithm for agents with continuous-time dynamics. The main proposal is that by incorporating a switching mechanism selecting the network topology to avoid malicious nodes from communicating, the remaining nodes will converge to a value closer to the original steady-state without the attacker being present. The switching occurs at discrete-time steps where each node evaluates the reputation score of the neighbors and deactivates/ignores edges in the network. We explore the proposed method with illustrative examples ranging from static topologies to dynamic ones, considering directed and undirected graphs, presenting several attacking scenarios that are successfully mitigated with our method. Finally, we compare the best undetectable attacking strategy and the commonly used approach named MSR, highlighting the advantages of our method. © 2022 The Author(s) Ngoc, P.H.A., Hieu, L.T. A novel approach to exponential stability in mean square of stochastic difference systems with delays (2022) 168, art. no. 105372, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85137643247&doi=10.1016%2fj.sysconle.2022.105372&partnerID=40&md5=46ff808a407fdef27cbdd1b53d24739d DOI: 10.1016/j.sysconle.2022.105372 AFFILIATIONS: Vietnam National University, Ho Chi Minh city, Viet Nam; International University, Department of Mathematics, Saigon, Thu Duc city, Viet Nam; Faculty of Mathematics-Information Technology Teacher Education, Dong Thap University, Dong Thap, Cao Lanh city, Viet Nam ABSTRACT: By a novel approach, we present in this paper for the first time, some explicit criteria for the exponential stability in mean square of solutions of general stochastic difference systems with time-varying delays. Both delay-independent and delay-dependent stability criteria are provided. A discussion and illustrative examples are given. © 2022 Elsevier B.V. Kawano, Y., Cao, M. Contraction analysis of virtually positive systems (2022) 168, art. no. 105358, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136616057&doi=10.1016%2fj.sysconle.2022.105358&partnerID=40&md5=56e6d99939f13a9f2858d69b331047c2 DOI: 10.1016/j.sysconle.2022.105358 AFFILIATIONS: Graduate School of Advanced Science and Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima, 739-8527, Japan; Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, AG, Gronigen, 9747, Netherlands ABSTRACT: Stability analysis methodologies tailored for positive linear systems have been generalized to cooperative nonlinear systems. However, some nonlinear network systems, such as epidemic dynamics characterized by susceptible–infected–susceptible models, are not cooperative. To apply the tools originally developed for cooperative systems to this class of non-cooperative systems, in this paper, we propose the concept of virtual positivity as a generalization of cooperativity. Non-cooperative (or even non-monotone) systems can be virtually positive. As the main result, we extend contraction conditions for cooperative systems to the virtually positive systems. Particularly, we derive necessary and sufficient conditions for incremental exponential stability (IES). Also, we show that the IES of a virtually positive system implies the exponential stability of the original nonlinear system if the virtual system has an equilibrium point of some property. © 2022 Elsevier B.V. Zhu, R., Liu, L. Stochastic stabilization of switching diffusion systems via an intermittent control strategy with delayed and sampled-data observations (2022) 168, art. no. 105362, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136262379&doi=10.1016%2fj.sysconle.2022.105362&partnerID=40&md5=2b42c110408297ccd489de464c6fa2f0 DOI: 10.1016/j.sysconle.2022.105362 AFFILIATIONS: College of Science, Hohai University, Nanjing, 210098, China ABSTRACT: This paper investigates the intermittent stochastic stabilization of switching diffusion systems (SDSs) via sampled data with time delays of state and mode. First, by virtue of analysis techniques for Markov chains, some estimates of the solutions for SDSs are derived. Second, with the aid of iteration by steps, a sufficient criterion is proposed for intermittent stochastic stabilization via sampled data with time delays of state and mode. Finally, a simulation example verifies the effectiveness of the theoretical results. © 2022 Elsevier B.V. Hoang, N.H., Nguyen, T.S., Le, T.K.P., Phan, T.T.H., Hussain, M.A., Dochain, D. Trajectory tracking for nonlinear systems using extended quadratic port-Hamiltonian models without input and state coordinate transformations (2022) 167, art. no. 105325, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134799190&doi=10.1016%2fj.sysconle.2022.105325&partnerID=40&md5=5a0f327e33cd9c4bfafce25a81ed43cb DOI: 10.1016/j.sysconle.2022.105325 AFFILIATIONS: Institute of Research and Development, Duy Tan University, Da Nang, 550000, Viet Nam; Faculty of Electrical-Electronic Engineering, Duy Tan University, Da Nang, 550000, Viet Nam; Faculty of Engineering, University Malaya, Kuala Lumpur, 50603, Malaysia; University of Technology, Vietnam National University, Ho Chi Minh City, Viet Nam; Hanoi Pedagogical University 2, Vinh Phuc, Viet Nam; ICTEAM, UCLouvain, 4-6 avenue G. Lemaître, Louvain-la-Neuve, B-1348, Belgium ABSTRACT: In this note, an enhanced trajectory tracking (or equivalently, tracking-error) approach is developed for the control of nonlinear systems whenever the stage of feedback passivation design prior to synthesizing state feedback controllers is impossible. To achieve this purpose while using the original state vector to retain its interpretation, it is possible without the use of input and state coordinate transformations to combine the system dynamics with the so-called extended quadratic port-Hamiltonian (PH) models (including possibly the quadratic pseudo PH models) which are then divided into non-relaxing and relaxing ones for further study on control benefits. Interestingly, both cases are associated to a unifying quadratic Hamiltonian storage function similar to that of electrical, mechanical, or electromechanical systems with a specific insight. Sufficient conditions for the global asymptotic or exponential convergence of the system trajectory to the reference one are shown. In addition, a Proportional–Integral action can be added to the tracking control for improving the closed-loop performance and robustness. The proposed approach is illustrated via two case studies, including the non-minimum phase Van de Vusse reaction system and the 3-DOF SCARA robot. © 2022 Elsevier B.V. Karafyllis, I., Theodosis, D., Papageorgiou, M. Constructing artificial traffic fluids by designing cruise controllers (2022) 167, art. no. 105317, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134600350&doi=10.1016%2fj.sysconle.2022.105317&partnerID=40&md5=53fb81824b820ddcb7662c7507a47344 DOI: 10.1016/j.sysconle.2022.105317 AFFILIATIONS: Department of Mathematics, National Technical University of Athens, Zografou Campus, Athens, 15780, Greece; Dynamic Systems and Simulation Laboratory, Technical University of Crete, Chania, 73100, Greece; Faculty of Maritime and Transportation, Ningbo University, Ningbo, China ABSTRACT: In this paper, we apply a Control Lyapunov Function methodology to design two families of cruise controllers for the two-dimensional movement of autonomous vehicles on lane-free roads using the bicycle kinematic model. The control Lyapunov functions are based on measures of the energy of the system with the kinetic energy expressed in ways similar to Newtonian or relativistic mechanics. The derived feedback laws (cruise controllers) are decentralized, as each vehicle determines its control input based on its own speed and on the relative speeds and distances from adjacent vehicles and from the boundary of the road. Moreover, the corresponding macroscopic models are derived, obtaining fluid-like models that consist of a conservation equation and a momentum equation with pressure and viscous terms. Finally, we show that, by selecting appropriately the parameters of the feedback laws, we can determine the physical properties of the “traffic fluid”, i.e. we get free hand to create an artificial fluid that approximates the emerging traffic flow. © 2022 Elsevier B.V. Silvestre, D. Set-valued estimators for Uncertain Linear Parameter-Varying systems (2022) 166, art. no. 105311, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133418324&doi=10.1016%2fj.sysconle.2022.105311&partnerID=40&md5=bc9ef5ef0e5bae243a300a1b89896029 DOI: 10.1016/j.sysconle.2022.105311 AFFILIATIONS: School of Science and Technology from the NOVA University of Lisbon (FCT/UNL), Caparica, 2829-516, Portugal; COPELABS, Lusófona University, Lisbon, Portugal; Institute for Systems and Robotics, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal ABSTRACT: In this paper, we tackle the problem of state estimation for uncertain linear systems when bounds are known for the disturbances, noise and initial state. Practical systems often have parameters that cannot be measured precisely at every iteration. The framework of Uncertain Linear Parameter-Varying systems (Uncertain LPVs) have attracted attention from the community and have seen applications from the aerospace industry to mechatronic systems, among many other examples. By formulating the problem as the solution of a feasibility program, we show that the optimal convex solution can be computed through an enumeration of the vertices of the estimates. Resorting to this result, three algorithms are proposed: an approximation algorithm using only set operations; an exact convex hull method returning the optimal convex set suitable for cases where estimates do not have a large number of vertices; and an event-triggering algorithm suitable for fault/attack detection that combines both the convex and nonconvex methods. Simulations are conducted using a motor speed model where some of the parameters cannot be measured exactly pointing out that the uncertainty matrices are responsible for the accuracy of the approximation algorithm, and also that the point-based method is suitable for online estimation. © 2022 Elsevier B.V. Katz, R., Fridman, E. Global finite-dimensional observer-based stabilization of a semilinear heat equation with large input delay (2022) 165, art. no. 105275, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131132309&doi=10.1016%2fj.sysconle.2022.105275&partnerID=40&md5=9fa1cc319369d2fa8d424b3a39a4fac3 DOI: 10.1016/j.sysconle.2022.105275 AFFILIATIONS: School of Electrical Engineering, Tel-Aviv University, Tel-Aviv, Israel ABSTRACT: We study global finite-dimensional observer-based stabilization of a semilinear 1D heat equation with globally Lipschitz semilinearity in the state variable. We consider Neumann actuation and point measurement. Using dynamic extension and modal decomposition we derive nonlinear ODEs for the modes of the state. We propose a controller that is based on a nonlinear finite-dimensional Luenberger observer. Our Lyapunov H1-stability analysis leads to LMIs, which are shown to be feasible for a large enough observer dimension and small enough Lipschitz constant. Next, we consider the case of a constant input delay r>0. To compensate the delay, we introduce a chain of M sub-predictors that leads to a nonlinear closed-loop ODE system, coupled with nonlinear infinite-dimensional tail ODEs. We provide LMIs for H1-stability and prove that for any r>0, the LMIs are feasible provided M and the observer dimension N are large enough and the Lipschitz constant is small enough. Numerical examples demonstrate the efficiency of the proposed approach. © 2022 Elsevier B.V. Ghaderi, N. A novel observer-based approach for the exponential stabilization of the string PDE with cubic nonlinearities (2022) 165, art. no. 105273, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131125968&doi=10.1016%2fj.sysconle.2022.105273&partnerID=40&md5=9714cc9aaee2da30d4dc543d8dca61e0 DOI: 10.1016/j.sysconle.2022.105273 AFFILIATIONS: Department of Applied Mathematics, Faculty of Mathematical Sciences, University of Guilan, Rasht, Iran ABSTRACT: The main objective of this study is to design an observer-based exponential output feedback controller for a one-dimensional vibrating string PDE with in-domain sources, and both anti-damper and anti-spring parameters and also both cubic velocity and nonlinear displacement at the boundary. Due to in-domain sources, the energy injection, cubic displacement and velocity nonlinearity, the unforced system is unstable and may represent a variety of dynamical behaviors. An exponential state feedback controller is first designed and also the well-posedness and the exponential stability of the closed-loop system is investigated. In addition, a novel exponential state observer is constructed, and then an observer-based exponential output feedback controller is proposed. At the end, the well-posedness and the exponential stability of the corresponding closed-loop system are obtained. The validity of the theoretical results is shown by numerical simulations. © 2022 Elsevier B.V. D'Jorge, A., Anderson, A., Ferramosca, A., González, A.H., Actis, M. On stability of nonzero set-point for nonlinear impulsive control systems (2022) 165, art. no. 105244, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130359722&doi=10.1016%2fj.sysconle.2022.105244&partnerID=40&md5=027cf3d93c35dd03717af1d06fe761ff DOI: 10.1016/j.sysconle.2022.105244 AFFILIATIONS: Institute of Technological Development for the Chemical Industry (INTEC), CONICET-Universidad Nacional del Litoral (UNL), Güemes 3450, Santa Fe, (3000), Argentina; Department of Management, Information and Production Engineering, University of Bergamo, Via Marconi 5, Dalmine (BG), 24044, Italy; CONICET - Universidad Nacional del Litoral (UNL), Facultad de Ingeniería Química, Santa Fe, Argentina ABSTRACT: The interest in non-linear impulsive systems (NIS) has been growing due to their impact on application problems such as disease treatments (diabetes, HIV, influenza, COVID-19, among many others), where the control action (drug administration) is given by short-duration pulses followed by time periods of null values. Within this framework, the concept of equilibrium needs to be extended (redefined) to allow the system to keep orbiting (between two consecutive pulses) in some state-space sets out of the origin, according to the usual objectives of most real applications. Although such sets can be characterized by means of a discrete-time system obtained by sampling the NIS at the impulsive times, no agreement has been reached on their asymptotic stability (AS) under optimizing control strategies. This paper studies the asymptotic stability of control equilibrium orbits for NIS, based on the underlying discrete-time system, in order to establish the conditions under which the AS for the latter leads to the AS for the former. Furthermore, based on the latter AS characterization, an impulsive Model Predictive Control (i-MPC) that feasibly stabilizes the non-linear impulsive system is presented. The biomedical problems of intravenous bolus administration of Lithium and antiretrovirals administration for HIV treatments are considered as simulation examples to demonstrate the controller performance © 2022 Elsevier B.V. Zhang, H., Deng, Y., Xia, J., Park, J.H., Shen, H., Chen, J. Accurate stabilization for linear stochastic systems based on region pole assignment and its applications (2022) 165, art. no. 105263, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130348846&doi=10.1016%2fj.sysconle.2022.105263&partnerID=40&md5=8e9d7e454effed385bb33ade6afe2cba DOI: 10.1016/j.sysconle.2022.105263 AFFILIATIONS: School of Mathematics Science, Liaocheng University, Shandong, 252000, China; Department of Electrical Engineering, Yeungnam University, Kyongsan, South Korea; School of Electrical and Information Engineering, Anhui University of Technology, Maanshan, 243002, China; School of Electrical Engineering and Automation, Jiangsu Normal University, Xuzhou, 221116, China ABSTRACT: On the premise of ensuring the stability of the closed-loop linear stochastic system, this paper uses region stability to further explore the precise control of its dynamic performance, which is an essential consideration in practical control. First, based on the relationship between the poles (eigenvalues) of the system state matrix and system performance, the sufficient conditions are presented for the distribution of system eigenvalues in the specific convex regions, i.e., a novel criterion for the region stability of the linear stochastic systems. Second, the region stabilization conditions are given by LMIs, which can guarantee that the system eigenvalues distribute in the connected region. Third, a new algorithm is designed to solve the stabilization condition of the eigenvalues of the state matrix located in the unconnected region. Accordingly, some dynamic performance indexes of linear stochastic systems can be controlled more accurately. Finally, two cases are provided to show the precise control for the performance indexes of the new stabilization method. © 2022 Elsevier B.V. Yao, L., Xie, D., Zhang, J. Cluster consensus of opinion dynamics with stubborn individuals (2022) 165, art. no. 105267, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130311186&doi=10.1016%2fj.sysconle.2022.105267&partnerID=40&md5=f52ca24231a6045dff689add60e8a654 DOI: 10.1016/j.sysconle.2022.105267 AFFILIATIONS: School of Mathematics, Tianjin University, Tianjin, China; College of Artificial Intelligence, Nankai University, Tianjin, China ABSTRACT: In this paper, we aim to study the cluster consensus of Friedkin–Johnsen (F-J) model with one or more stubborn nodes. Firstly, for F-J model with only one stubborn node, by algebra theory and graph theory, we not only establish consensus criterion for F-J model without oblivious agents but also establish some couple-cluster consensus criteria for F-J model with oblivious agents. Secondly, for F-J model with more than one stubborn individual, we present a novel network partition strategy to divide F-J model into many subnetworks, where every stubborn node and its pure-reachable nodes (a special reachable node without stubborn nodes except the starting node appearing in the walk) form a subnetwork, and all oblivious individuals of F-J model also constitute a subnetwork if they exist. By our network partition, some necessary and sufficient cluster consensus criteria are given. In addition, if there exist some oblivious individuals, our main results show that the influence of the initial opinion of stubborn root on the final opinion of non-oblivious individuals is proportional to the stubborn extent of the stubborn root to its initial opinion. Finally, some simulations are provided to illustrate the results. © 2022 Elsevier B.V. Zhao, Y., Zhu, Q. Stability of highly nonlinear neutral stochastic delay systems with non-random switching signals (2022) 165, art. no. 105261, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129978449&doi=10.1016%2fj.sysconle.2022.105261&partnerID=40&md5=eaf2b1e6a7935b3102ef12d5c8d64af4 DOI: 10.1016/j.sysconle.2022.105261 AFFILIATIONS: MOE-LCSM, School of Mathematics and Statistics, Hunan Normal University, Changsha, Hunan, 410081, China; The Key Laboratory of Control and Optimization of Complex Systems, College of Hunan Province, Hunan Normal University, Changsha, 410081, China ABSTRACT: For the last few decades, many works on stability criteria have been established for neutral stochastic delay systems, which are modeled by stochastic differential delay equations. Some of these works do not involve switching signals, and others contain Markovian switching signals. This paper studies highly nonlinear neutral stochastic delay systems with non-random switching signals. Firstly, the rule of non-random switching signals is imposed. Then, by using the Lyapunov function method and the mode-dependent average dwell time approach, the existence and boundedness of unique global solution is discussed for highly nonlinear neutral stochastic delay systems with non-random switching signals. In addition, without the linear growth condition, asymptotic stability and exponential stability are obtained. In the last part of the article, an illustrative example is provided to show the effectiveness of the obtained results. © 2022 Elsevier B.V. Lhachemi, H., Prieur, C. Output feedback stabilization of reaction–diffusion PDEs with a non-collocated boundary condition (2022) 164, art. no. 105238, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129923855&doi=10.1016%2fj.sysconle.2022.105238&partnerID=40&md5=1c2116147a989dd711cbfaf3e0fdaf93 DOI: 10.1016/j.sysconle.2022.105238 AFFILIATIONS: Université Paris-Saclay, CNRS, CentraleSupélec, Laboratoire des signaux et systèmes, 91190, Gif-sur-Yvette, France; Université Grenoble Alpes, CNRS, Grenoble-INP, GIPSA-lab, F-38000, Grenoble, France ABSTRACT: This paper addresses the control design problem of output feedback stabilization of a reaction–diffusion PDE with a non-collocated boundary condition. More precisely, we consider a reaction–diffusion equation with a boundary condition describing a proportional relationship between the left and right Dirichlet traces. Such a boundary condition naturally emerges, e.g., in the context of reaction–diffusion partial differential equations presenting a transport term and with a periodic Dirichlet boundary condition. The control input takes the form of the left Neumann trace. Finally, the measurement is selected as a pointwise Dirichlet measurement located either in the domain or at the boundary. The adopted control strategy takes the form of a finite-dimensional controller coupling a state feedback and a finite-dimensional observer. The stability of the closed-loop system is obtained provided the order of the observer is selected to be large enough. Finally, we extend this result to the establishment of an input-to-state stability estimate with respect to an additive perturbation in the application of the boundary control. © 2022 Elsevier B.V. Mazenc, F., Malisoff, M. Feedback stabilization and robustness analysis using bounds on fundamental matrices (2022) 164, art. no. 105212, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129719460&doi=10.1016%2fj.sysconle.2022.105212&partnerID=40&md5=ec388658076eb4407c9ad8843635da6b DOI: 10.1016/j.sysconle.2022.105212 AFFILIATIONS: Inria Saclay, L2S-CNRS-CentraleSupélec, 3 rue Joliot Curie, Gif-sur-Yvette, 91192, France; Department of Mathematics, Louisiana State University, Baton RougeLA 70803-4918, United States ABSTRACT: We prove a new robust stabilization theorem for time-varying systems that have sampled measurements and time-varying disturbances, and we provide new observer designs, using novel bounds for fundamental matrices for systems with disturbances. Our main tools use properties of Metzler matrices and positive systems. © 2022 Elsevier B.V. Gan, D., Liu, Z. Performance analysis of the compressed distributed least squares algorithm (2022) 164, art. no. 105228, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129555381&doi=10.1016%2fj.sysconle.2022.105228&partnerID=40&md5=5253f940fe3ee05918742c17af8d9fde DOI: 10.1016/j.sysconle.2022.105228 AFFILIATIONS: Key Laboratory of Systems and Control, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China; School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China ABSTRACT: In this paper, we consider the distributed estimation problem of unknown high-dimensional sparse signals for a random dynamic system. We propose a compressed distributed algorithm by using the compressive sensing theory and the distributed least squares (LS) algorithm. Under a compressed cooperative persistent excitation condition, the upper bound of the estimation error is established which is positively related to the restricted isometry constant. Our results are obtained without relying on some stringent conditions such as independency or stationarity of the regression vectors. Finally, we provide a simulation example to show that the compressed distributed least squares algorithm has better performance than the regularized distributed LS algorithm with l1 penalty for the estimation of high-dimensional sparse signals. © 2022 Elsevier B.V. Grüne, L., Meurer, T. Finite-dimensional output stabilization for a class of linear distributed parameter systems — A small-gain approach (2022) 164, art. no. 105237, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129473920&doi=10.1016%2fj.sysconle.2022.105237&partnerID=40&md5=3149b5dec40edd90aa74a041453702d6 DOI: 10.1016/j.sysconle.2022.105237 AFFILIATIONS: Chair of Applied Mathematics, Mathematical Institute, University of Bayreuth, Bayreuth, 95440, Germany; Chair of Automation and Control, Kiel University, Kaiserstrasse 2, Kiel, 24143, Germany ABSTRACT: A small-gain approach is proposed to analyze closed-loop stability of linear diffusion-reaction systems under finite-dimensional observer-based state feedback control. For this, the decomposition of the infinite-dimensional system into a finite-dimensional slow subsystem used for design and an infinite-dimensional residual fast subsystem is considered. The effect of observer spillover in terms of a particular (dynamic) interconnection of the subsystems is thoroughly analyzed for in-domain and boundary control as well as sensing. This leads to the application of a small-gain theorem for interconnected systems based on input-to-output stability and unbounded observability properties. Moreover, an approach is presented for the computation of the required dimension of the slow subsystem used for controller design. Simulation scenarios for both scalar and coupled linear diffusion-reaction systems are used to underline the theoretical assessment and to give insight into the resulting properties of the interconnected systems. © 2022 Elsevier B.V. Morris, I.D. Marginally unstable discrete-time linear switched systems with highly irregular trajectory growth (2022) 163, art. no. 105216, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127744632&doi=10.1016%2fj.sysconle.2022.105216&partnerID=40&md5=b5d693f185adf7038cf38cf75c0ecb9b DOI: 10.1016/j.sysconle.2022.105216 AFFILIATIONS: School of Mathematical Sciences, Queen Mary University of London, Mile End Road, UK, London, E1 4NS, United Kingdom ABSTRACT: We investigate the uniform stability properties of discrete-time linear switched systems subject to arbitrary switching, focusing on the “marginally unstable” regime in which the system is not Lyapunov stable but in which trajectories cannot escape to infinity at exponential speed. For a discrete linear system of this type without switching the fastest-growing trajectory must grow as an exact polynomial function of time, and a significant body of prior research has focused on investigating how far this intuitive picture can be extended from systems without switching to cases where switching is present. In this note we give an example of a family of discrete linear switched systems in three dimensions, with two switching states, for which this intuition fails badly: for a generic member of this family the maximal rate of uniform growth of escaping trajectories can be made arbitrarily slow along one subsequence of times and yet also faster than any prescribed slower-than-linear function along a complementary subsequence of times. Using this construction we give new counterexamples to a conjecture of Chitour, Mason and Sigalotti and obtain a negative answer to a related question of Jungers, Protasov and Blondel. Our examples have the additional feature that marginal stability and marginal instability are densely intermingled in the same parameter space. © 2022 The Author(s) Kong, H., Sukkarieh, S., Arnold, T.J., Chen, T., Zheng, W.X. The noise covariances of linear Gaussian systems with unknown inputs are not uniquely identifiable using autocovariance least-squares (2022) 162, art. no. 105172, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125697580&doi=10.1016%2fj.sysconle.2022.105172&partnerID=40&md5=7811bd041b8380ab9f92ccd2b2f438a6 DOI: 10.1016/j.sysconle.2022.105172 AFFILIATIONS: Department of Mechanical and Energy Engineering, Southern University of Science and Technology, Shenzhen, 518055, China; Australian Centre for Field Robotics, University of Sydney, NSW, 2006, Australia; Independent researcher, Tucson, AZ 85756, United States; School of Data Science and Shenzhen Research Institute of Big Data, The Chinese University of Hong Kong, Shenzhen, 518172, China; School of Computer, Data and Mathematical Sciences, Western Sydney University, Sydney, NSW 2751, Australia ABSTRACT: Existing works in optimal filtering for linear Gaussian systems with arbitrary unknown inputs assume perfect knowledge of the noise covariances in the filter design. This is impractical and raises the question of whether and under what conditions one can identify the noise covariances of linear Gaussian systems with arbitrary unknown inputs. This paper considers the above identifiability question using the correlation-based autocovariance least-squares (ALS) approach. In particular, for the ALS framework, we prove that (i) the process noise covariance Q and the measurement noise covariance R cannot be uniquely jointly identified; (ii) neither Q nor R is uniquely identifiable, when the other is known. This not only helps us to have a better understanding of the applicability of existing filtering frameworks under unknown inputs (since almost all of them require perfect knowledge of the noise covariances) but also calls for further investigation of alternative and more viable noise covariance methods under unknown inputs. Especially, it remains to be explored whether the noise covariances are uniquely identifiable using other correlation-based methods. We are also interested to use regularization for noise covariance estimation under unknown inputs, and investigate the relevant property guarantees for the covariance estimates. The above topics are the main subjects of our current and future work. © 2022 Elsevier B.V. Della Rossa, M., Tanwani, A. Instability of dwell-time constrained switched nonlinear systems (2022) 162, art. no. 105164, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125259505&doi=10.1016%2fj.sysconle.2022.105164&partnerID=40&md5=bacfc8575f1c3be60af03806ceb1be2d DOI: 10.1016/j.sysconle.2022.105164 AFFILIATIONS: Université Catholique de Louvain, Louvain-La-Neuve, Belgium; CNRS, LAAS – CNRS, Toulouse, University of Toulouse, France ABSTRACT: Analyzing the stability of switched nonlinear systems under dwell-time constraints, this article investigates different scenarios where all the subsystems have a common globally asymptotically stable (GAS) equilibrium, but for the switched system, the equilibrium is not uniformly GAS for arbitrarily large values of dwell-time. We motivate our study with the help of examples showing that, if near the origin all the vector fields decay at a rate slower than the linear vector fields, then the trajectories are ultimately bounded for large enough dwell-time. On the other hand, if away from the origin, the vector fields do not grow as fast as the linear vector fields, then we can only guarantee local asymptotic stability for large enough dwell-times, with region of attraction depending on the dwell-time itself. We formalize our observations for homogeneous systems, and show that, even if the origin is not uniformly GAS with dwell-time switching for nonlinear systems, it still holds that the trajectories starting from a bounded set converge to a neighborhood of the origin if the dwell-time is large enough. © 2022 Elsevier B.V. Boulouz, A., Bounit, H., Hadd, S. Feedback theory approach to positivity and stability of evolution equations (2022) 161, art. no. 105167, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125479410&doi=10.1016%2fj.sysconle.2022.105167&partnerID=40&md5=428ee9b24d32d21b96d4f614d3481f5a DOI: 10.1016/j.sysconle.2022.105167 AFFILIATIONS: Department of Mathematics, Faculty of Sciences, Ibn Zohr University, Hay Dakhla, BP8106, Agadir, 80000, Morocco ABSTRACT: In this paper, we study the positivity and (uniform) exponential stability of a large class of perturbed semigroups. Our approach is essentially based on feedback theory of infinite-dimensional linear systems. The obtained results are applied to the stability of hyperbolic systems including those with a delay at the boundary conditions. The efficiency of our theoretical results is illustrated by some numerical simulations. © 2022 Elsevier B.V. Astolfi, D., Praly, L., Marconi, L. Harmonic internal models for structurally robust periodic output regulation (2022) 161, art. no. 105154, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124193992&doi=10.1016%2fj.sysconle.2022.105154&partnerID=40&md5=90850149c2f07eccc488e14e816ccef6 DOI: 10.1016/j.sysconle.2022.105154 AFFILIATIONS: Univ Lyon, université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 boulevard du 11 novembre 1918, Villeurbanne, F-69100, France; Centre Automatique et Systèmes, MINES ParisTech, Université PSL, Paris, France; CASY-DEI, University of Bologna, Bologna, 40123, Italy ABSTRACT: This note deals with the problem of output regulation for nonlinear systems in presence of periodic exogenous signals. We investigate the asymptotic properties of a controller given by an internal model designed by adding harmonics on the regulation error, and a static state feedback stabilizing the augmented system of the plant and of the internal model. The solution mimics internal model-based structures adopted for linear systems by showing the asymptotic properties that are guaranteed in the nonlinear case in presence of “generic” plant variations. Forwarding technique is adopted in the design of the stabilizer. We shed also light on the linear case by presenting a new easy-to-check condition under which the regulator equations admit a robust solution. © 2022 Elsevier B.V. Mazenc, F., Malisoff, M., Barbalata, C., Jiang, Z.-P. Event-triggered control for linear time-varying systems using a positive systems approach (2022) 161, art. no. 105131, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124083477&doi=10.1016%2fj.sysconle.2022.105131&partnerID=40&md5=46120cb6c7fab4bc5ed45e6e9108ef37 DOI: 10.1016/j.sysconle.2022.105131 AFFILIATIONS: Inria Saclay, L2S-CNRS-CentraleSupélec, 3 rue Joliot Curie, Gif-sur-Yvette, 91192, France; Department of Mathematics, Louisiana State University, Baton Rouge, LA 70803-4918, United States; Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA 70803, United States; Department of Electrical and Computer Engineering, New York University, Brooklyn, NY 11201, United States ABSTRACT: This paper presents a new design for the event-triggered output feedback control of uncertain linear time-varying systems. Departing from the traditional treatments of event-triggered linear time-invariant systems, it is shown that factoring of fundamental solutions as products of solutions of matrix differential equations, together with small-gain arguments and the notions of interval observers and positive systems, lead to a new class of robust event-triggered output-feedback controllers. A key innovation is our use of new event triggers, which use vectors of absolute values instead of the usual Euclidean 2-norms. An illustrative example of a curve tracking system from marine robotics validates the efficacy of the proposed design scheme. © 2022 Elsevier B.V. Bin, M. Generalized recursive least squares: Stability, robustness, and excitation (2022) 161, art. no. 105144, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124024985&doi=10.1016%2fj.sysconle.2022.105144&partnerID=40&md5=44010561ca5cef5d88fcbc00793f0bec DOI: 10.1016/j.sysconle.2022.105144 AFFILIATIONS: Department of Electrical and Electronic Engineering, Imperial College London, London, UK, United Kingdom ABSTRACT: We study a class of recursive least-squares estimators in an errors-in-variables setting where disturbances affect both the regressor and the regressand variables. We prove the existence and stability of an optimal steady state and robustness with respect to the disturbances in form of input-to-state and input–output stability relative to the unperturbed steady-state trajectories. Depending on the choice of some design parameters, different specific estimators can be realized within the considered class, each of which is associated with a different underlying optimization problem and with different excitation requirements for the unperturbed regressor. As expected, we find that persistence of excitation is associated with uniform, in fact exponential, convergence. In addition, we also show that choices of the design parameters are possible for which convergence and robustness hold without persistence of excitation and with the same asymptotic gain, the only difference being a loss of uniformity in the convergence rate. © 2022 Elsevier B.V. Yang, X., Yu, Z. FBSDEs involving time delays and advancements on infinite horizon and LQ problems with delays (2022) 161, art. no. 105149, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123897356&doi=10.1016%2fj.sysconle.2022.105149&partnerID=40&md5=f136d3286487b4f61bf8ed2f17983171 DOI: 10.1016/j.sysconle.2022.105149 AFFILIATIONS: School of Mathematics, Shandong University, Jinan, 250100, China ABSTRACT: This paper is concerned with a class of coupled forward–backward stochastic differential equations (FBSDEs, for short) involving time delays and time advancements on infinite horizon. By introducing a randomized Lipschitz condition and a randomized monotonicity condition, the unique solvability of FBSDEs is obtained. Then the theoretical result is applied to a linear–quadratic (LQ, for short) problem of a time-delayed system with random coefficients. An explicit expression of the unique optimal control is obtained. © 2022 Elsevier B.V. Bonnard, B., Cots, O., Gergaud, J., Wembe, B. Abnormal geodesics in 2D-Zermelo navigation problems in the case of revolution and the fan shape of the small time balls (2022) 161, art. no. 105140, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123888239&doi=10.1016%2fj.sysconle.2022.105140&partnerID=40&md5=7498072800aa480414a7915d475fc3fc DOI: 10.1016/j.sysconle.2022.105140 AFFILIATIONS: Toulouse University, INP-ENSEEIHT-IRIT, UMR CNRS 5505, 2 rue Camichel, Toulouse, 31071, France; Inria, 2004 route des Lucioles F-06902, Sophia Antipolis, France; Toulouse University, IRIT-UPS, UMR CNRS 5505, 118 route de Narbonne, Toulouse, 31062, France; Institut de Mathématiques de Bourgogne, UMR CNRS 5584, 9 avenue Alain Savary, Dijon, 21078, France ABSTRACT: In this article, based on two case studies, we discuss the role of abnormal geodesics in planar Zermelo navigation problems. Such curves are limit curves of the accessibility set, in the domain where the current is strong. The problem is set in the frame of geometric time optimal control, where the control is the heading angle of the ship and in this context, abnormal curves are shown to separate time minimal curves from time maximal curves and are both small-time minimizing and maximizing. We describe the small-time minimal balls. For bigger time, a cusp singularity can occur in the abnormal direction, which corresponds to a conjugate point along the non-smooth image. It is interpreted in terms of the regularity property of the time minimal value function. © 2022 Elsevier B.V. Meng, T., Xie, Y., Lin, Z. Suboptimal output consensus of a group of discrete-time heterogeneous linear non-minimum phase systems (2022) 161, art. no. 105134, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123797418&doi=10.1016%2fj.sysconle.2022.105134&partnerID=40&md5=d70293b462c40d9d3d7ca6c7cd6f88df DOI: 10.1016/j.sysconle.2022.105134 AFFILIATIONS: Charles L. Brown Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA 22904-4743, United States; Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019, United States ABSTRACT: This paper formulates the suboptimal output consensus problem for a discrete-time heterogeneous linear multi-agent system with unstable zero dynamics, where each agent possesses its own objective function and the sum of all these private objective functions, called the overall objective function, is to be minimized. Mild assumptions on the communication topology and the agent dynamics are made under which a parameterized distributed consensus protocol based on low gain feedback is proposed for each agent. The multi-agent system is shown to achieve suboptimal output consensus under the proposed protocols in the sense that the states of all agents remain bounded while their outputs converge to a pre-specified arbitrarily small neighborhood of the optimal point as long as the design parameter is chosen small enough. Simulation results are presented that demonstrate the proposed design. © 2022 Elsevier B.V. Hosseinzadeh, M., Sinopoli, B., Kolmanovsky, I., Baruah, S. ROTEC: Robust to early termination command governor for systems with limited computing capacity (2022) 161, art. no. 105142, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123778147&doi=10.1016%2fj.sysconle.2022.105142&partnerID=40&md5=b4f59c4c6361cfb41c2ad7bca6bc8d2b DOI: 10.1016/j.sysconle.2022.105142 AFFILIATIONS: Department of Electrical and Systems Engineering, Washington University in St. Louis, St. Louis, MO 63130, United States; Department of Aerospace Engineering, University of Michigan, Ann Arbor, MI 48109, United States; Department of Computer Science and Engineering, Washington University in St. Louis, St. Louis, MO 63130, United States ABSTRACT: A Command Governor (CG) is an optimization-based add-on scheme to a nominal closed-loop system. It is used to enforce state and control constraints by modifying reference commands. This paper considers the implementation of a CG on embedded processors that have limited computing resources and must execute multiple control and diagnostics functions; consequently, the time available for CG computations is limited and may vary over time. To address this issue, a robust to early termination command governor is developed which embeds the solution of a CG problem into the internal states of a virtual continuous-time dynamical system which runs in parallel to the process. This virtual system is built so that its trajectory converges to the optimal solution (with a tunable convergence rate), and provides a sub-optimal but feasible solution whenever its evolution is terminated. This allows the designer to implement a CG strategy with a small sampling period (and consequently with a minimum degradation in its performance), while maintaining its constraint-handling capabilities. Simulations are carried out to assess the effectiveness of the developed scheme in satisfying performance requirements and real-time schedulability conditions for a practical vehicle rollover example. © 2022 Elsevier B.V. Liu, J., Hao, R., Guo, B.-Z. Order reduction-based uniform approximation of exponential stability for one-dimensional Schrödinger equation (2022) 160, art. no. 105136, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123630802&doi=10.1016%2fj.sysconle.2022.105136&partnerID=40&md5=ad159ef3ca4e60a18be8c88ddb960096 DOI: 10.1016/j.sysconle.2022.105136 AFFILIATIONS: School of Mathematical Sciences, Shanxi University, Taiyuan, 030006, China; School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China; Key Laboratory of System and Control, Academy of Mathematics and Systems Science, Academia Sinica, Beijing, 100190, China; School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China ABSTRACT: This paper considers the uniform exponential stability approximation of a one-dimensional Schrödinger system with boundary damping. The continuous system is known to be exponentially stable. Firstly, the order reduction method is adopted to transform the original system into an equivalent one. Two second-order semi-discretized finite difference schemes are derived for both the transformed system and the original system, which are shown to be equivalent to each other. Secondly, the Lyapunov function method is used to prove the uniform exponential stability of the semi-discretized transformed system, which is parallel to the proof of the continuous transformed system. Finally, the solution of the semi-discretized system converges weakly to the solution of the original system and the discrete energy converges to the continuous energy. © 2022 Elsevier B.V. Li, Z., Xu, L., Ma, W. Global attracting sets and exponential stability of stochastic functional differential equations driven by the time-changed Brownian motion (2022) 160, art. no. 105103, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122234477&doi=10.1016%2fj.sysconle.2021.105103&partnerID=40&md5=5671eb9a54d7abc824975a173eaeaf48 DOI: 10.1016/j.sysconle.2021.105103 AFFILIATIONS: School of Information and Mathematics, Yangtze University, Jingzhou, Hubei 434023, China ABSTRACT: In this paper, we study a class of stochastic functional differential equations driven by the time-changed Brownian motion. Some sufficient conditions ensuring the existence of the global attracting sets of considered equations are presented. As applications, some new criteria for the exponential stability in mean square of the considered equations are obtained. Lastly, some examples are investigated to illustrate the theory. © 2021 Elsevier B.V. Liang, Q., Ong, C.-J., She, Z. Output consensusability of network with two-dimensional heterogeneous linear agents via static diffusive output feedback (2022) 159, art. no. 105084, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122504393&doi=10.1016%2fj.sysconle.2021.105084&partnerID=40&md5=f93511636de9992132e5420af8d177b7 DOI: 10.1016/j.sysconle.2021.105084 AFFILIATIONS: School of Mathematical Sciences, Beihang University, Beijing, 100191, China; Department of Mechanical Engineering, National University of Singapore119077, Singapore ABSTRACT: This paper addresses the output consensusability of network with two-dimensional heterogeneous linear agents via static diffusive output feedback. It provides a procedure to not only verify the existence of an internal model, which is a well-known necessary condition for output consensus, but also obtain the largest internal model. Once the internal model exists, sufficient conditions are given for output consensusability. Specifically, when the internal model is one-dimensional, the existence of at least one individual agent whose trajectories converge to the internal model is sufficient for output consensusability; when the internal model is two-dimensional, if the differences of the control inputs among the agents are small enough, then the network is consensusable under certain conditions. Finally, two examples are given to illustrate the effectiveness of our results. © 2021 Elsevier B.V. Alagoz, B.B., Deniz, F.N., Koseoglu, M. An efficient PID-based optimizer loop and its application in De Jong's functions minimization and quadratic regression problems (2022) 159, art. no. 105090, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120865084&doi=10.1016%2fj.sysconle.2021.105090&partnerID=40&md5=72ab252a7e35a2e5e3be3f043e335d1a DOI: 10.1016/j.sysconle.2021.105090 AFFILIATIONS: Inonu University, Department of Computer Engineering, Malatya, Turkey; Inonu University, Department of Electrical and Electronics Engineering, Malatya, Turkey ABSTRACT: The Proportional–Integral–Derivative (PID) control law has been commonly used for process control in control engineering applications. However, it has potential to work as a solver in optimization problems. This study introduces a PID-based optimizer loop that is designed to solve nonlinear, unconstrained, multi-parameter optimization problems. To achieve the minimization of multi-parameter positive real objective functions by using a closed loop PID control loop, a slope sentient objective function model is suggested to allow zero-crossing of the error signal. Thus, this objective function model enhances the convergence efficiency of the PID-based optimizer loop by indicating slope direction of the objective function and operating in both positive and negative error regions. The boundedness and convergence theorems for the proposed PID optimizer loop are presented, and a theoretical background for the PID-based minimization is established. To demonstrate practical minimization performance, numerical applications of the proposed PID optimizer loops are illustrated in the solution of two fundamental optimization problems. These are the minimization of 30 parameters De Jong's functions and the solution of quadratic regression problems. Also, an experimental study is presented for the quadratic regression modeling of measurement data from a hole-drilling experiment. Optimization results reveal that the proposed PID-based optimizer system can improve convergence speed and accuracy compared to performances of fundamental nonlinear optimization techniques. © 2021 Elsevier B.V. Orłowski, J., Chaillet, A., Destexhe, A., Sigalotti, M. Adaptive control of Lipschitz time-delay systems by sigma modification with application to neuronal population dynamics (2022) 159, art. no. 105082, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120172587&doi=10.1016%2fj.sysconle.2021.105082&partnerID=40&md5=aa3e07b60a3e2c4f4d67bcf65c8f124e DOI: 10.1016/j.sysconle.2021.105082 AFFILIATIONS: Université Paris-Saclay, CNRS, CentraleSupélec, Laboratoire des signaux et systèmes, Gif-sur-Yvette, 91190, France; Institut Universitaire de France, France; Université Paris-Saclay, CNRS, Institute of Neuroscience, Saclay, 91400, France; Inria, Laboratoire Jacques-Louis Lions, Sorbonne Université, CNRS, Université de Paris, Paris, 75005, France ABSTRACT: Adaptive control using the σ-modification provides an easily implementable way to stabilize systems with uncertain or fluctuating parameters. Motivated by a specific application from neuroscience, we extend here this methodology to nonlinear time-delay systems ruled by globally Lipschitz dynamics. In order to make the result more handy in practice, we provide an explicit construction of a Lyapunov–Krasovskii functional (LKF) with linear bounds and strict dissipation rate based on the knowledge of an LKF with quadratic bounds and point-wise dissipation rate. When applied to a model of neuronal populations involved in Parkinson's disease, the benefits with respect to a pure proportional stabilization scheme are discussed through numerical simulations. © 2021 Elsevier B.V. Marino, R., Tomei, P. On exponentially convergent parameter estimation with lack of persistency of excitation (2022) 159, art. no. 105080, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119896481&doi=10.1016%2fj.sysconle.2021.105080&partnerID=40&md5=ad291d2fff8287767241f5c37b642891 DOI: 10.1016/j.sysconle.2021.105080 AFFILIATIONS: University of Roma Tor Vergata, Roma, Italy ABSTRACT: Given a linear regression model, the problem of exponentially convergent identification of a vector of p constant parameters is addressed, without the assumption that the regressor is persistently exciting. A new definition of lack of persistency of excitation of order q, with 0≤q≤p, is introduced, which reduces to the well-known persistency of excitation condition in the special case q=0. This definition implies that the kernel of the Gram matrix of the regressor has constant dimension q. Gradient and least squares identification algorithms may be modified on the basis of such a kernel computation, so that exponential convergence and robustness of parameter estimation errors is achieved both for gradient and least squares algorithms, even without persistency of excitation. © 2021 Elsevier B.V. Schaub, P., Vogt, P., Konigorski, U. Robust coupling control using pole region assignment (2021) 158, art. no. 105067, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119195719&doi=10.1016%2fj.sysconle.2021.105067&partnerID=40&md5=cf318b89168f7155fd51e4600d529456 DOI: 10.1016/j.sysconle.2021.105067 AFFILIATIONS: Control Systems and Mechatronics Lab, Technische Universität Darmstadt, Landgraf-Georg-Str. 4, Darmstadt, 64283, Germany ABSTRACT: In this paper, we develop a constructive method for designing robust linear coupling controllers with respect to the closed-loop eigenvalues and eigenstructure. The design method is based on a multi-model approach for parameter-varying systems, which is used to calculate constraints for a complete state feedback. The associated controller structure assures the fulfillment of given algebraic coupling conditions and is finally parameterized in a pole region assignment procedure. Necessary and sufficient conditions for the existence of a robust coupling controller are determined and an approximate method is developed for the case in which these conditions are not fulfilled. The developed method is applied to an example system. © 2021 Elsevier B.V. Ao, Y., Jia, Y. Output feedback control of mixed H2/H∞ multi-agent consensus via an inner auxiliary system approach (2021) 158, art. no. 105064, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118535987&doi=10.1016%2fj.sysconle.2021.105064&partnerID=40&md5=4396b39e43804cb4b52f58e15163784e DOI: 10.1016/j.sysconle.2021.105064 AFFILIATIONS: The Seventh Research Division and the Center for Information and Control, School of Automation Science and Electrical Engineering, Beihang University (BUAA), Beijing, 100191, China ABSTRACT: This paper investigates the mixed H2/H∞ consensus control problem for linear multi-agent systems subject to two types of disturbances. For multi-agent systems with undirected graph, the full control and standard output feedback control are considered, respectively. To this end, inner auxiliary systems are constructed for the transformed subsystems, based on which consensus conditions are derived in terms of linear matrix inequalities with an algebraic Riccati equation. It is shown that designed protocols not only can guarantee consensus with prescribed mixed H2/H∞ performance, but also result in a similar separation property as in the design of the controllers of single linear systems. Moreover, we extend the inner auxiliary system approach and the separation property to the directed graph case. Finally, some numerical examples are presented to illustrate the effectiveness of the theoretical results. © 2021 Elsevier B.V. Kreiss, J., Trégouët, J.-F. Input redundancy: Definitions, taxonomy, characterizations and application to over-actuated systems (2021) 158, art. no. 105060, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118259426&doi=10.1016%2fj.sysconle.2021.105060&partnerID=40&md5=5457a718b17692a134c820e6c4630832 DOI: 10.1016/j.sysconle.2021.105060 AFFILIATIONS: Universite de Lorraine, CNRS, CRAN, Nancy, F-54000, France; Univ Lyon, INSA Lyon, Université Claude Bernard Lyon 1, Ecole Centrale de Lyon, CNRS, Ampère UMR5005, Villeurbanne, F-69621, France ABSTRACT: For input redundant systems, it is possible to construct distinct inputs producing identical outputs, from the same initial state. Thus, a system is input redundant if it is not left-invertible. In this paper, a rigorous framework is proposed to support this new definition. From the observation that state trajectories induced by the two inputs can be identical or not, an enriched taxonomy of input redundancy is also designed. A comprehensive set of characterizations is associated with the proposed definitions. A degree of redundancy is also conceived. This allows to carry out a thorough comparison with the state-of-the-art. Finally, the fact that over-actuated systems are input redundant is formally proved. This fact leads to a control design framework which can easily cope with over-actuated systems equipped with dynamical actuators. © 2021 Elsevier B.V. Wang, L., Zhou, X. Minimal time control problem of a linear heat equation with memory (2021) 157, art. no. 105052, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116929175&doi=10.1016%2fj.sysconle.2021.105052&partnerID=40&md5=eefd5840fbb6eb846ee5157a011b1ab5 DOI: 10.1016/j.sysconle.2021.105052 AFFILIATIONS: School of Mathematics and Statistics, Computational Science Hubei Key Laboratory, Wuhan University, Wuhan, 430072, China; School of Mathematics and Statistics, Lingnan Normal University, Zhanjiang, 524048, China ABSTRACT: This paper studies a minimal time control problem for a linear heat equation with memory. The purpose of such a problem is to find a control (among certain control constraint set), which steers the solution of the heat equation with memory from a given initial state to a given target as soon as possible. In this paper, we study the existence of optimal control to this problem, show the bang–bang property of the optimal control and build up a necessary and sufficient condition of the optimal control. © 2021 Elsevier B.V. Zhang, J., Qi, J. Compensation of spatially-varying state delay for a first-order hyperbolic PIDE using boundary control (2021) 157, art. no. 105050, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116754133&doi=10.1016%2fj.sysconle.2021.105050&partnerID=40&md5=b2de01df0963bdab51c045a324677af2 DOI: 10.1016/j.sysconle.2021.105050 AFFILIATIONS: College of Information Science and Technology, Donghua University, Shanghai, 201620, China; Engineering Research Center of Digitized Textile and Fashion Technology Ministry of Education, Donghua University, Shanghai, 201620, China ABSTRACT: This paper develops a spatially-varying delay-compensated control for a first-order hyperbolic partial integro differential equation (PIDE). By introducing a 2-dimensional (2-D) transport partial differential equation (PDE) with a spatially-dependent propagation speed, we transform the delay from the time domain to space domain and which results an equivalent cascade system composed of a PIDE and a transport PDE. The control design is based on the backstepping method with a novel transformation which contains the weighted integration of the shifted state of the transport PDE (actuator state) besides the weighted integration of the PIDE state and the weighted double integration of the actuator state. The kernel equations and the inverse kernel equations are proved to be well-posedness by the successive approximation method, respectively. The finite-time stability of the closed-loop system is established and finally, a simulation example is provided to illustrate the effectiveness of the proposed delay-compensated controller. © 2021 Elsevier B.V. Cannarsa, D., Sigalotti, M. Approximately controllable finite-dimensional bilinear systems are controllable (2021) 157, art. no. 105028, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115374956&doi=10.1016%2fj.sysconle.2021.105028&partnerID=40&md5=11fb5eba000a9044b5cf70ccbcd89e02 DOI: 10.1016/j.sysconle.2021.105028 AFFILIATIONS: Université de Paris, Sorbonne Université, CNRS, Inria, Institut de Mathématiques de Jussieu-Paris Rive Gauche, Paris, F-75013, France; Laboratoire Jacques-Louis Lions, Sorbonne Université, Université de Paris, CNRS, Inria, Paris, France ABSTRACT: We show that a bilinear control system is approximately controllable if and only if it is controllable in Rn∖{0}. We approach this property by looking at the foliation made by the orbits of the system, and by showing that there does not exist a codimension one foliation in Rn∖{0} with dense leaves that are everywhere transversal to the radial direction. The proposed geometric approach allows to extend the results to homogeneous systems that are angularly controllable. © 2021 Elsevier B.V. Bruce, A.L., Goel, A., Bernstein, D.S. Necessary and sufficient regressor conditions for the global asymptotic stability of recursive least squares (2021) 157, art. no. 105005, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114699846&doi=10.1016%2fj.sysconle.2021.105005&partnerID=40&md5=7f783f879b65a4911148fabdf59f330b DOI: 10.1016/j.sysconle.2021.105005 AFFILIATIONS: Aerospace Engineering Department, University of Michigan, Ann Arbor, MI 48109, United States ABSTRACT: In recursive least squares (RLS), a persistently exciting (PE) regressor guarantees global asymptotic stability (GAS) of the estimation error relative to the zero equilibrium, and hence convergence of the parameter estimates to their true values. It is known, however, that PE is sufficient but not necessary for GAS, and thus GAS might be achieved even if the regressor is not PE. Since analyses based on PE are ubiquitous in the recursive estimation literature, the existence of non-PE regressors that ensure GAS raises the question of how PE can be directly generalized into a necessary and sufficient condition for the GAS of RLS, and whether or not such a generalization would provide a simple characterization of non-PE regressors for which RLS is GAS. In this paper, we introduce WPE, a direct generalization of PE that is necessary and sufficient for GAS, and explain how it can be understood as a “non-uniform” extension of PE to specific classes of summation windows and lower bound sequences. Next, we show that WPE is equivalent to a condition that emerges from extending certain proofs of non-negative series divergence, such as Oresme's divergence proof for the harmonic series, to sequences of real symmetric positive-semidefinite matrices. © 2021 Elsevier B.V. Zhang, L., Zhang, W. Global solutions of stochastic Stackelberg differential games under convex control constraint (2021) 156, art. no. 105020, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114264927&doi=10.1016%2fj.sysconle.2021.105020&partnerID=40&md5=082e0eac9b67b1d4556140312852fe83 DOI: 10.1016/j.sysconle.2021.105020 AFFILIATIONS: School of Mathematics, Renmin University of China, Beijing, 100872, China; School of Science, Beijing University of Posts and Telecommunications, Beijing, 100876, China ABSTRACT: This paper is concerned with a Stackelberg stochastic differential game, where the systems are driven by stochastic differential equation (SDE for short), in which the control enters the randomly disturbed coefficients (drift and diffusion). The control region is postulated to be convex. By making use of the first-order adjoint equation (backward stochastic differential equation, BSDE for short), we are able to establish the Pontryagin's maximum principle for the leader's global Stackelberg solution, within adapted open-loop structure and closed-loop memoryless information one, respectively, where the term global indicates that the leader's domination over the entire game duration. Since the follower's adjoint equation turns out to be a BSDE, the leader will be confronted with a control problem where the state equation is a kind of fully coupled forward–backward stochastic differential equation (FBSDE for short). As an application, we study a class of linear–quadratic (LQ for short) Stackelberg games in which the control process is constrained in a closed convex subset Γ of full space Rm. The state equations are represented by a class of fully coupled FBSDEs with projection operators on Γ. By means of monotonicity condition method, the existence and uniqueness of such FBSDEs are obtained. When the control domain is full space, we derive the resulting backward stochastic Riccati equations. © 2021 Elsevier B.V. Imae, T., Cai, K. Structural controllability and time-to-control of directed scale-free networks with minimum number of driver nodes (2021) 156, art. no. 105025, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113989609&doi=10.1016%2fj.sysconle.2021.105025&partnerID=40&md5=73acd50e00231a0d2a5acf7cb248c319 DOI: 10.1016/j.sysconle.2021.105025 AFFILIATIONS: Department of Electrical and Information Engineering, Osaka City University, Japan ABSTRACT: In this paper we study structural controllability and time-to-control of directed scale-free networks, and propose algorithms to guarantee these properties with the minimum number of driver nodes. Structural controllability is a qualitative (i.e. topological) measure of the ability to steer the network to a desired state from an arbitrary initial state; while time-to-control measures how fast the above steering can be done. First, we develop an algorithm that generates directed scale-free networks which are provably structurally controllable with only one driver node. Moreover, considering the tradeoff between control cost (number of driver nodes) and control performance (time-to-control), we propose another algorithm that constructs directed scale-free networks which can be steered to a desired state within a prescribed time bound and with the minimum number of driver nodes. © 2021 Elsevier B.V. Farina, M., Caspani, A. Model-based fault isolability and isolation of persistent faults: Centralized and distributed implementations (2021) 156, art. no. 105006, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113292443&doi=10.1016%2fj.sysconle.2021.105006&partnerID=40&md5=de346624af7edd23a43dfbacf84d231d DOI: 10.1016/j.sysconle.2021.105006 AFFILIATIONS: Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano, Via Ponzio 34/5, Milan, 20133, Italy; e-NOVIA, Via San Martino 12, Milan, 20122, Italy ABSTRACT: Research on system monitoring, fault detection, and fault isolation is extremely important for guaranteeing reliability, safety, integrity, and efficiency of plants, technical processes, and especially safety-critical systems. In this paper we first discuss, analyze, and compare two known centralized observer-based fault isolation schemes. Secondly we devise and discuss their distributed implementations. We finally evaluate and compare the potentialities of the different fault isolation schemes and their distributed implementations considering a benchmark case study. © 2021 Elsevier B.V. Yao, Y., Sun, J. Optimal control of multi-task Boolean control networks via temporal logic (2021) 156, art. no. 105007, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113145133&doi=10.1016%2fj.sysconle.2021.105007&partnerID=40&md5=f29d11c3a969f43f564c03cc45fa6b0a DOI: 10.1016/j.sysconle.2021.105007 AFFILIATIONS: School of Mathematical Sciences, Tongji University, Shanghai, 200092, China ABSTRACT: Boolean control networks (BCNs) with temporal logic specifications have great potential to deal with multiple tasks or complex environments. We first express the tasks of BCNs with temporal logic specifications, and transform these specifications into finite time sets dwell problems. By using the semi-tensor product (STP), some results that satisfying the specifications of temporal logic through time-varying control are obtained. Our method provides a unified framework for studying the stabilizability, synchronizability, path planning and other issues of BCNs. The controller design algorithms are then proposed to generate state sequences that fulfill the given tasks as much as possible while minimizing the cost function. Finally, two examples are given to verify the effectiveness of the theoretical results. © 2021 Elsevier B.V. Vijayan, N., L.A., P. Smoothed functional-based gradient algorithms for off-policy reinforcement learning: A non-asymptotic viewpoint (2021) 155, art. no. 104988, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85110534153&doi=10.1016%2fj.sysconle.2021.104988&partnerID=40&md5=ce8a9e445fe1a2ba83d6eaad5110414d DOI: 10.1016/j.sysconle.2021.104988 AFFILIATIONS: Department of Computer Science and Engineering, Indian Institute of Technology Madras, India ABSTRACT: We propose two policy gradient algorithms for solving the problem of control in an off-policy reinforcement learning (RL) context. Both algorithms incorporate a smoothed functional (SF) based gradient estimation scheme. The first algorithm is a straightforward combination of importance sampling-based off-policy evaluation with SF-based gradient estimation. The second algorithm, inspired by the stochastic variance-reduced gradient (SVRG) algorithm, incorporates variance reduction in the update iteration. For both algorithms, we derive non-asymptotic bounds that establish convergence to an approximate stationary point. From these results, we infer that the first algorithm converges at a rate that is comparable to the well-known REINFORCE algorithm in an off-policy RL context, while the second algorithm exhibits an improved rate of convergence. © 2021 Elsevier B.V. Li, Z., Guo, Y., Gui, W. Asymptotical feedback controllability of probabilistic logic control networks (2021) 154, art. no. 104986, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85108822911&doi=10.1016%2fj.sysconle.2021.104986&partnerID=40&md5=64be0463fbd0b8ec3b2b85d69464498f DOI: 10.1016/j.sysconle.2021.104986 AFFILIATIONS: School of Automation, Central South University, Changsha, 410083, China ABSTRACT: In this paper, we investigate the asymptotical feedback controllability (AFC) of probabilistic logic control networks (PLCNs). First, the concept of asymptotical feedback reachability (AFR) is proposed, allowing us to define AFC. Then, we prove that a state is asymptotically feedback reachable if and only if (iff) it is a control fixed point, and there is an admissible path to it from any other state. Based on this, we prove that a PLCN is asymptotically feedback controllable iff every state is asymptotically feedback stabilizable. Moreover, we express the criteria for the AFR and AFC of PLCNs in terms of the reachability matrix, which are easily checkable. The relations between the AFC and other definitions of controllability are also discussed. Finally, an illustrative example is provided to show the usage of the proposed results and to demonstrate the design of feedbacks achieving transitions between states. © 2021 Elsevier B.V. Lazar, M., Weston, J. Greedy algorithm for parameter dependent operator Lyapunov equations (2021) 154, art. no. 104968, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107822352&doi=10.1016%2fj.sysconle.2021.104968&partnerID=40&md5=854f7ed18766e24fae92b7c00ec4fadc DOI: 10.1016/j.sysconle.2021.104968 AFFILIATIONS: University of Dubrovnik, Ćira Carića 4, Dubrovnik, 20 000, Croatia ABSTRACT: The aim of this paper is to provide an efficient method for solving a family of parameter dependent, algebraic Lyapunov equations in an infinite dimensional setting. Our analysis is based on previous work on reduced modeling and (weak) greedy algorithms for parameter dependent PDEs and abstract equations in Banach spaces. The major contribution is threefold. Firstly, the problem is resolved in an infinite dimensional setting, thus enabling applications to PDEs and equations governed by unbounded operators. Secondly, we demonstrate the boundedness and coercive properties of the Lyapunov operator in appropriate functional spaces. Lastly, the method is applied to the control theory, enabling rapid construction of approximate control functions for a wide range of control problems. © 2021 Meng, Q., Yang, H., Jiang, B. On structural accessibility of network nonlinear systems (2021) 154, art. no. 104972, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107741482&doi=10.1016%2fj.sysconle.2021.104972&partnerID=40&md5=53088573dcc846075119f6cfd04688f6 DOI: 10.1016/j.sysconle.2021.104972 AFFILIATIONS: College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 211106, China ABSTRACT: This paper studies the structural accessibility for a class of network nonlinear systems (NNSs) with meromorphic vector fields. Nonlinear eigenvector and differential one-form are employed to establish a Kalman rank typed strong accessibility condition, which helps to prove that the structural accessibility of the considered NNSs is equivalent to the structural controllability of their linearized systems. Such an equivalence allows us to analyse and design NNSs by using the well-developed linear system theories. A chemical reaction system example is taken to illustrate the theoretical result. © 2021 Elsevier B.V. Grass, D., Feichtinger, G., Kort, P.M., Seidl, A. Why (some) abnormal problems are “normal” (2021) 154, art. no. 104971, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85107299471&doi=10.1016%2fj.sysconle.2021.104971&partnerID=40&md5=161ba83d8d437e7a94c1ff57f4169743 DOI: 10.1016/j.sysconle.2021.104971 AFFILIATIONS: International Institute for Applied Systems Analysis (IIASA), Schloßplatz 1, Laxenburg, 2361, Austria; Department for Operations Research and Control Systems, Institute of Statistics and Mathematical Methods in Economics, Wiedner Hauptstraße 8, 1040 Vienna, Vienna University of Technology, Vienna, Austria; Tilburg School of Economics and Management, Tilburg University, PO Box 90153, Tilburg, LE 5000, Netherlands; Department of Economics, University of Antwerp, Prinsstraat 13, Antwerp, 2000, Belgium; Department of Business Decisions and Analytics, Oskar-Morgenstern-Platz 1, 1090 Vienna, University of Vienna, Vienna, Austria ABSTRACT: In abnormal optimal control problems it is necessary to basically ignore the objective for certain state values in order to be able to determine the optimal control. In the past, abnormal problems were considered to be degenerated problems that did not fit to any real application. In the present paper we discuss reasons for the occurrence of abnormality. We show that abnormality can be an integral part of a meaningful problem rather than to be a sign for degeneracy. © 2021 The Author(s) Krener, A.J. Boundary control of the beam equation by linear quadratic regulation (2021) 153, art. no. 104949, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105873926&doi=10.1016%2fj.sysconle.2021.104949&partnerID=40&md5=b5528d25b46e3fa2cd678876bdf86f14 DOI: 10.1016/j.sysconle.2021.104949 AFFILIATIONS: Naval Postgraduate School, 833 Dyer Road MontereyCA 93943-5216, United States ABSTRACT: We present and solve a Linear Quadratic Regulator (LQR) for the boundary control of the beam equation. We use the simple technique of completing the square to get an explicit solution. By decoupling the spatial frequencies we are able to reduce an infinite dimensional LQR to an infinite family of two dimensional LQRs each of which can be solved explicitly. © 2021 Ayala, V., Jouan, P., Torreblanca, M.L., Zsigmond, G. Time optimal control for linear systems on Lie groups (2021) 153, art. no. 104956, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105589540&doi=10.1016%2fj.sysconle.2021.104956&partnerID=40&md5=a31b08cb2e871d28c790ca4d8ca338a1 DOI: 10.1016/j.sysconle.2021.104956 AFFILIATIONS: Instituto de Alta Investigación, Universidad de Tarapacá, Casilla 7D, Arica, Chile; Lab. R. Salem, CNRS UMR 6085, université de Rouen, avenue de l'université BP 12, Saint-Étienne-du-Rouvray, 76801, France; Universidad Nacional de San Agustín de Arequipa, Calle Santa Catalina, Nro. 117, Arequipa, Peru; Université de Rouen, France ABSTRACT: This paper is devoted to the study of time optimal control of linear systems on Lie groups. General necessary conditions of the existence of time minimizers are stated when the controls are unbounded. The results are applied to systems on various Lie groups. © 2021 Elsevier B.V. Sarsılmaz, S.B., Yucelen, T. Distributed control of linear multiagent systems with global and local objectives (2021) 152, art. no. 104928, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105315754&doi=10.1016%2fj.sysconle.2021.104928&partnerID=40&md5=780e5395531155ad081b65c39a257d85 DOI: 10.1016/j.sysconle.2021.104928 AFFILIATIONS: The William E. Boeing Department of Aeronautics and Astronautics, University of Washington, Seattle, WA 98195, United States; Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, United States ABSTRACT: In this paper, we consider distributed control problems for high-order linear time-invariant multiagent systems with not only global but also local objectives over fixed directed communication graph topologies. The former is either leaderless synchronization or synchronization to a leader. Local objectives for a subset of agents, on the other hand, are tasks determined around the global objective by agent-specific exosystems. First, we construct reference models for all agents via two existing synchronization results, introduce two classes of distributed controllers, and define the considered problems. We then solve them by utilizing the converging-input converging-state property for a class of linear systems and the feedforward design methodology from the linear output regulation theory. Finally, numerical examples are presented to demonstrate the problems and the theoretical results. © 2021 Elsevier B.V. Karafyllis, I. On the relation of IOS-gains and asymptotic gains for linear systems (2021) 152, art. no. 104934, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105261662&doi=10.1016%2fj.sysconle.2021.104934&partnerID=40&md5=9cf46a2cd55c3ca56b6fc8245bd2d70a DOI: 10.1016/j.sysconle.2021.104934 AFFILIATIONS: Department of Mathematics, National Technical University of Athens, Zografou Campus, Athens, 15780, Greece ABSTRACT: This paper presents a fundamental relation between Output Asymptotic Gains (OAG) and Input-to-Output Stability (IOS) gains for linear systems. For any Input-to-State Stable, strictly causal linear system the minimum OAG is equal to the minimum IOS-gain. Moreover, both quantities can be computed by solving a specific optimal control problem and by considering only periodic inputs. The result is valid for wide classes of linear systems (including delay systems or systems described by PDEs). The characterization of the minimum IOS-gain is important because it allows the non-conservative computation of the IOS-gains, which can be used in a small-gain analysis. The paper also presents a number of cases for finite-dimensional linear systems, where exact computation of the minimum IOS-gain can be performed. © 2021 Elsevier B.V. Medianu, S., Lefèvre, L. Structural identifiability of linear Port Hamiltonian systems (2021) 151, art. no. 104915, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103978634&doi=10.1016%2fj.sysconle.2021.104915&partnerID=40&md5=af3f94d84b94ab91f375bde17b0d8476 DOI: 10.1016/j.sysconle.2021.104915 AFFILIATIONS: Univ. Grenoble Alpes, Grenoble INP, LCIS, Valence, 26000, France ABSTRACT: This paper, puts in discussion the structural identifiability of LTI Port-Controlled Hamiltonian (PCH) systems, in order to develop a specific identification and control theory. This is due to their remarkable properties of power conservation and stability under power preserving interconnection. The main part of the paper, presents a power based identifiability approach, with specific propositions and definitions. It is based on the power knowledge associated with the system ports, interconnected by a Dirac structure, for selected input signals. In a preliminary section, corresponding transfer functions, system outputs, Markov parameters, observability conditions, port-observability or infinite Grammians are defined for each port. Beside this, a port-identifiability concept is introduced for the identifiability analysis of one port. It is proved that between the input and system ports, a specific model can be determined for identification analysis, preserving in the same time the PCH structure. As examples to demonstrate the theory, a controlled LC circuit and a DC motor are selected for the lossless and lossy cases, respectively. © 2021 Elsevier B.V. Srinivasan, M., Abate, M., Nilsson, G., Coogan, S. Extent-compatible control barrier functions (2021) 150, art. no. 104895, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101699820&doi=10.1016%2fj.sysconle.2021.104895&partnerID=40&md5=a5e1d9c4b0eabc4f5d00cfa8a370b7a2 DOI: 10.1016/j.sysconle.2021.104895 AFFILIATIONS: School of Electrical and Computer Engineering, Georgia Institute of Technology, United States; School of Mechanical Engineering, Georgia Institute of Technology, United States; School of Civil and Environmental Engineering, Georgia Institute of Technology, United States ABSTRACT: Safety requirements in dynamical systems are commonly enforced with set invariance constraints over a safe region of the state space. Control barrier functions, which are Lyapunov-like functions for guaranteeing set invariance, are an effective tool to enforce such constraints and guarantee safety when the system is represented as a point in the state space. In this paper, we introduce extent-compatible control barrier functions as a tool to enforce safety for the system explicitly accounting for its volume (extent) within an ambient workspace. In order to implement the extent-compatible control barrier functions framework, we first propose a sum-of-squares optimization program that is solved pointwise in time to ensure safety. Since sum-of-squares programs can be computationally prohibitive, we next propose an approach that instead considers a finite number of points sampled on the extent boundary. The result is a quadratic program for guaranteed safety that retains the computational advantage of traditional barrier functions. While this alternative is generally more conservative than the sum-of-squares approach, we show that conservatism is reduced by increasing the number of sampled points. Simulation and robotic implementation results are provided. © 2021 Elsevier B.V. Garab, Á., Pituk, M. Convergence in nonautonomous linear differential equations with Kirchhoff coefficients (2021) 149, art. no. 104884, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85101040345&doi=10.1016%2fj.sysconle.2021.104884&partnerID=40&md5=7070ae2de61be7a330161b0d0b420eed DOI: 10.1016/j.sysconle.2021.104884 AFFILIATIONS: Mathematics Department, University of Klagenfurt, Universitätsstraße 65–67, Klagenfurt, A-9020, Austria; Department of Mathematics, University of Pannonia, Egyetem út 10, Veszprém, H-8200, Hungary ABSTRACT: A class of nonautonomous linear ordinary differential equations is considered. The coefficient matrices are Metzler matrices with zero column sums such that their directed graphs have a common directed spanning tree. It is shown that if the off-diagonal elements of the coefficients are uniformly positive along the common directed spanning tree, then under mild additional assumptions the convergence of the Perron vectors of the coefficient matrices implies that all solutions tend to a finite limit at infinity. The value of the limit can be expressed in terms of the initial data. © 2021 The Author(s) Balter, A.G., Pelsser, A. Quantifying ambiguity bounds via time-consistent sets of indistinguishable models (2021) 149, art. no. 104877, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099707112&doi=10.1016%2fj.sysconle.2021.104877&partnerID=40&md5=b535c71aa9395ab619af1b622cad6990 DOI: 10.1016/j.sysconle.2021.104877 AFFILIATIONS: Tilburg University, Netherlands; Netspar, Netherlands; Maastricht University, Netherlands; University of Amsterdam, Netherlands ABSTRACT: Models can be wrong and recognising their limitations is important in financial and economic decision making under uncertainty. Robust strategies, which are least sensitive to perturbations of the underlying model, take uncertainty into account. Interpreting the explicit set of alternative models surrounding the baseline model has been difficult so far. We specify alternative models via a time-consistent set of equivalent probability measures and derive a quantitative bound on the uncertainty set. We find an explicit ex ante relation between the size of this set, and the Type I and II error probabilities on the statistical test that is hypothetically performed to investigate whether the alternative model specification could be rejected at a future test horizon. The hypothetical test is constructed to obtain all alternative models that are indistinguishable from the baseline model. We also link the ambiguity bound, which is now a function of interpretable variables, to numerical values on several divergence measures and illustrate our methodology on a robust investment problem. © 2021 The Author(s) Saldi, N. Regularized stochastic team problems (2021) 149, art. no. 104876, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099615315&doi=10.1016%2fj.sysconle.2021.104876&partnerID=40&md5=5c7fbfb79507d80320b6cabf7665e4ae DOI: 10.1016/j.sysconle.2021.104876 AFFILIATIONS: Özyeğin University, Çekmeköy, İstanbul, Turkey ABSTRACT: In this paper, we introduce regularized stochastic team problems. Under mild assumptions, we prove that there exists a unique fixed point of the best response operator, where this unique fixed point is the optimal regularized team decision rule. Then, we establish an asynchronous distributed algorithm to compute this optimal strategy. We also provide a bound that shows how the optimal regularized team decision rule performs in the original stochastic team problem. © 2021 Elsevier B.V. Miranda-Villatoro, F.A., Sepulchre, R. Differential dissipativity analysis of reaction–diffusion systems (2021) 148, art. no. 104858, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098966814&doi=10.1016%2fj.sysconle.2020.104858&partnerID=40&md5=af026c7a0ae76f4bb1edca1b4dfdae7a DOI: 10.1016/j.sysconle.2020.104858 AFFILIATIONS: Engineering Department, University of Cambridge, United Kingdom ABSTRACT: This note shows how classical tools from linear control theory can be leveraged to provide a global analysis of nonlinear reaction–diffusion models. The approach is differential in nature. It proceeds from classical tools of contraction analysis and recent extensions to differential dissipativity. © 2020 Elsevier B.V. Polyakov, A. Homogeneous Lyapunov functions for homogeneous infinite dimensional systems with unbounded nonlinear operators (2021) 148, art. no. 104854, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098694351&doi=10.1016%2fj.sysconle.2020.104854&partnerID=40&md5=91cebc7f60f1adffce530c309474e372 DOI: 10.1016/j.sysconle.2020.104854 AFFILIATIONS: Inria, Univ. Lille, CNRS, UMR 9189 - CRIStAL, Lille, F-59000, France ABSTRACT: The existence of a locally Lipschitz continuous homogeneous Lyapunov function is proven for a class of asymptotically stable homogeneous infinite dimensional systems with unbounded nonlinear operators. © 2020 Elsevier B.V. Farraa, B.B., Abbou, R., Loiseau, J.J. Inventory control of a class of logistic networks (2021) 147, art. no. 104845, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097586065&doi=10.1016%2fj.sysconle.2020.104845&partnerID=40&md5=ee01020492c259d43579356a29d26451 DOI: 10.1016/j.sysconle.2020.104845 AFFILIATIONS: Laboratory of Digital Science of Nantes - LS2N, Université Bretagne Loire, 1 Rue de la Noë, Nantes, 44321, France ABSTRACT: This paper focuses on a prediction-based control for a class of convolution systems subject to constant input delays, also known as the reduction approach. We propose here a characterization of the D-invariance property of polytope sets for continuous-time systems. Our motivations come from production management, where a general model for a production network is considered. The system is subject to product losses and multiple delays, with bounded demand. This model is transformed into an equivalent free-delay system using Artstein reduction. The question of regulating the inventory levels of the nodes of this production network is then reduced to a pair of sub-problems, that are the regulation of the equivalent system without delay, and the relationship between the output of the system and that of the reduced system. A pair of conditions is therefore obtained, for the verification that a large class of control solutions allow to satisfy the external demand, while meeting the constraints that are imposed to the system. At the end, explicit conditions are found for an example of a supply chain with two nodes. © 2020 Elsevier B.V. Ghodrat, M., Marquez, H.J. L2-incremental gain stability of linear systems with nonlinear Lipschitz actuator (2021) 147, art. no. 104846, . Cited 1 time. https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097336592&doi=10.1016%2fj.sysconle.2020.104846&partnerID=40&md5=580ba484501c2aaa159c3cbe8731d4b2 DOI: 10.1016/j.sysconle.2020.104846 AFFILIATIONS: Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada ABSTRACT: In this manuscript we study the problem of finding incremental L2-gain of a class of nonlinear systems obtained by combining a linear plant and a general dynamic controller and a nonlinear actuator. The proposed method allows for the existence of possible nonlinear imperfections in the actuator. The justification of the proposed approach is provided through a compelling example. © 2020 Elsevier B.V. Perryman, R., Taylor, J.A., Karney, B. Port-Hamiltonian based control of water distribution networks (2022) 170, art. no. 105402, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141929060&doi=10.1016%2fj.sysconle.2022.105402&partnerID=40&md5=68d512a70d79678d6a1cfc7ca04cb603 DOI: 10.1016/j.sysconle.2022.105402 AFFILIATIONS: Electrical and Computer Engineering, University of Toronto, Toronto, ON M5S 3G4, Canada; Civil Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada ABSTRACT: We design controllers for a nonlinear model of a water distribution network (WDN). Most existing approaches to the control of WDNs model the pumps as simple pressure gains. We show that a commonly used empirical model of a pump leads to a port-Hamiltonian (pH) and hence stable system. We use standard arguments to show that WDNs are incrementally pH, and show that local PI controllers preserve stability. These controllers are robust in that they do not require specific knowledge of the equilibrium input. We further show that controllers based on physical feedback that WDN operators usually rely on have merit in the pH framework. All of these controllers are shown to be useful in mitigating disturbances and tracking setpoints corresponding to assignable equilibria. © 2022 Elsevier B.V. Biswas, A., Pradhan, S. Ergodic risk-sensitive control for regime-switching diffusions (2022) 170, art. no. 105399, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141815321&doi=10.1016%2fj.sysconle.2022.105399&partnerID=40&md5=b5c06f595698d75770dc0233c77cefa5 DOI: 10.1016/j.sysconle.2022.105399 AFFILIATIONS: Indian Institute of Science Education and Research Pune, Dr. Homi Bhabha Road, Pune, 411008, India; Department of Mathematics and Statistics, Queen's University, 48 University Ave, Kingston, Canada ABSTRACT: In this article, we study the ergodic risk-sensitive control problem for controlled regime-switching diffusions. Under a blanket stability hypothesis, we solve the associated nonlinear eigenvalue problem for weakly coupled systems and characterize the optimal stationary Markov controls via a suitable verification theorem. We also consider the near-monotone case and obtain the existence of principal eigenfunction and optimal stationary Markov controls. © 2022 Elsevier B.V. Tranninger, M., Seeber, R., Rueda-Escobedo, J.G., Horn, M. Strong∗ detectability and observers for linear time-varying systems (2022) 170, art. no. 105398, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141456688&doi=10.1016%2fj.sysconle.2022.105398&partnerID=40&md5=33c800e8f69a1d92af1a9e14d49cef59 DOI: 10.1016/j.sysconle.2022.105398 AFFILIATIONS: Institute of Automation and Control, Graz University of Technology, Inffeldgasse 21B/II, Graz, 8010, Austria; Christian Doppler Laboratory for Model Based Control of Complex Test Bed Systems, Institute of Automation and Control, Graz University of Technology, Inffeldgasse 21B/II, Graz, 8010, Austria; Fachgebiet Regelungssysteme und Netzleittechnik, Brandenburgische Technische Universität Cottbus - Senftenberg, Siemens-Halske-Ring 14, Cottbus, 03046, Germany ABSTRACT: This work presents a notion of strong detectability for linear time-varying systems affected by unknown inputs. It is shown that this notion is equivalent to detectability of an auxiliary system without unknown inputs. This allows a straightforward observer design for dependable state estimation in the presence of unknown inputs. The design reduces to a deterministic Kalman filter design problem, where the observer gains can be obtained from the solution of a differential Riccati equation. The efficacy of the proposed approach is demonstrated by means of two examples. © 2022 The Author(s) Bouggar, D., El Fatini, M., El Hichamy, I., Nasri, B.R., Sekkak, I. Near-optimal stochastic control for radiotherapy treatment in a random cancer model (2022) 170, art. no. 105400, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141329592&doi=10.1016%2fj.sysconle.2022.105400&partnerID=40&md5=136895e9b1150bc1f9b34ccd2499024e DOI: 10.1016/j.sysconle.2022.105400 AFFILIATIONS: Laboratory of PDE's, Algebra and Spectral Geometry. Faculty of Sciences, Ibn Tofail University, Kénitra, BP 133, Morocco; Centre de recherche en santé publique and Département de médecine sociale et préventive, Ecole de santé publique de l'Université de Montréal 101, avenue du Parc, Montréal (Québec), H3N 1X9, Canada ABSTRACT: In this paper, we investigate the near-optimal control of a stochastic model for cancer treatment by radiotherapy. We have studied the existence and uniqueness of the positive solution of the stochastic system. We have established a priori estimates of the radiation, where we obtained the sufficient and necessary conditions for the near-optimal control problem of the stochastic model for cancer treatment using the maximum condition of the Hamiltonian function and the Ekeland principle. We illustrated some numerical simulations to support our theoretical results. © 2022 Elsevier B.V. Groff, L.B., Gomes da Silva, J.M., Jr., Valmorbida, G. Event-triggered control for discrete-time piecewise affine systems (2022) 170, art. no. 105394, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141269740&doi=10.1016%2fj.sysconle.2022.105394&partnerID=40&md5=57a004d360354b676c16c119ce1952df DOI: 10.1016/j.sysconle.2022.105394 AFFILIATIONS: Dept. of Automation and Energy Systems (DELAE), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil; L2S, CentraleSupélec, CNRS, Université Paris Saclay, Inria-Sclay Projet DISCO, Gif-Sur-Yvette, France ABSTRACT: This work addresses the event-triggered control (ETC) of discrete-time piecewise affine systems. We propose a method to design a triggering strategy relying on an implicit representation of piecewise affine systems. Thanks to this implicit representation based on ramp functions, we propose a partition-dependent piecewise quadratic functions to define the trigger criterion and use a piecewise quadratic Lyapunov function candidate to derive conditions to certify the global exponential stability of the origin under the ETC strategy. Since the stability conditions can be expressed as linear matrix inequalities constraints, we propose a convex optimization solution to design the triggering function parameters and to compute the Lyapunov function to ensure the closed-loop stability and a reduction on the control updates. The approach is illustrated by numerical examples. © 2022 Elsevier B.V. Schmoderer, T., Respondek, W. Null-forms of conic systems in R3 are determined by their symmetries (2022) 170, art. no. 105397, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85140976289&doi=10.1016%2fj.sysconle.2022.105397&partnerID=40&md5=5d41c2ae58e02e71c9c7ed4b863894a7 DOI: 10.1016/j.sysconle.2022.105397 AFFILIATIONS: Laboratoire de Mathématiques, INSA Rouen Normandie, Rouen, France; Institute of Automatic Control, Technical University of Łódź, Łódź, Poland ABSTRACT: We address the problem of characterisation of null-forms of conic 3-dimensional systems, that is, control-affine systems whose field of admissible velocities forms a conic (without parameters) in the tangent space. Those systems have been previously identified as the simplest control systems under a conic nonholonomic constraint or as systems of zero curvature. In this work, we propose a direct characterisation of null-forms of conic systems among all control-affine systems by studying the Lie algebra of infinitesimal symmetries. Namely, we show that the Lie algebra of infinitesimal symmetries characterises uniquely null-forms of conic systems. © 2022 Elsevier B.V. Grüne, L., Krügel, L., Müller, M.A. Multiobjective strict dissipativity via a weighted sum approach (2022) 170, art. no. 105396, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85140803905&doi=10.1016%2fj.sysconle.2022.105396&partnerID=40&md5=c496b8064e8a258ef0cebce2b1ce9894 DOI: 10.1016/j.sysconle.2022.105396 AFFILIATIONS: Universität Bayreuth, Mathematical Institute, Chair of Applied Mathematics, Bayreuth, Germany; Leibniz Universität Hannover, Institute of Automatic Control, Hannover, Germany ABSTRACT: We consider nonlinear model predictive control (MPC) with multiple competing cost functions. This leads to the formulation of multiobjective optimal control problems (MO OCPs). Since the design of MPC algorithms for directly solving multiobjective problems is rather complicated, particularly if terminal conditions shall be avoided, we use an indirect approach via a weighted sum formulation for solving these MO OCPs. This way, for each set of weights we obtain an optimal control problem with a single objective. In economic MPC it is known that strict dissipativity is the key assumption for concluding performance and stability results. We thus investigate under which conditions a convex combination of strictly dissipative stage costs again yields a stage cost for which the system is strictly dissipative. We first give conditions for problems with linear dynamics and then move on to consider fully nonlinear optimal control problems. We derive both necessary and sufficient conditions on the individual cost functions and on the weights to conclude strict dissipativity and illustrate our findings with numerical examples. © 2022 Elsevier B.V. Tomar, M.S., Kawan, C., Zamani, M. Numerical over-approximation of invariance entropy via finite abstractions (2022) 170, art. no. 105395, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85140437250&doi=10.1016%2fj.sysconle.2022.105395&partnerID=40&md5=8d05fea356633e45d7fd8761c6506fa1 DOI: 10.1016/j.sysconle.2022.105395 AFFILIATIONS: Computer Science Department, University of Colorado Boulder, United States; Institute of Informatics, LMU Munich, Germany ABSTRACT: For a closed-loop system with a digital channel between the sensor and controller, invariance entropy quantifies the smallest average rate of information above which a compact subset Q of the state set can be made invariant. There exist different versions of invariance entropy for deterministic and uncertain control systems, which are equivalent in the deterministic case. In this paper, we present the first numerical approaches to obtain rigorous upper bounds of these quantities. Our approaches are based on set-valued numerical analysis and graph-theoretic constructions. We combine existing algorithms from the literature to carry out our computations for several linear and nonlinear examples. A comparison with the theoretical values of the entropy shows that our bounds are of the same order of magnitude as the actual values. © 2022 Elsevier B.V. Krishnamurthy, P., Khorrami, F. Efficient non-conservative realization of dynamic scaling-based controllers via matrix pencils for uncertain nonlinear strict-feedback systems (2022) 169, art. no. 105393, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85140141225&doi=10.1016%2fj.sysconle.2022.105393&partnerID=40&md5=c0f835e6ff8358c40492866c5ba82705 DOI: 10.1016/j.sysconle.2022.105393 AFFILIATIONS: Control/Robotics Research Laboratory (CRRL), Dept. of ECE, NYU Tandon School of Engineering, 5 MetroTech Center, Brooklyn, NY 11201, United States ABSTRACT: We propose a new matrix pencil based approach for design of state-feedback and output-feedback controllers for uncertain nonlinear strict-feedback-like systems. While the dynamic controller structure is based on dynamic high-gain scaling, we cast the design procedure within a general matrix pencil structure unlike prior results that utilized conservative algebraic bounds of terms arising in Lyapunov inequalities. The design freedoms in the controller are extracted in terms of generalized eigenvalues associated with matrix pencils formulated to capture detailed structures (locations and state dependences) of uncertain terms in the system dynamics. The approach is developed under both state-feedback (dynamic high-gain scaling based controller) and output-feedback (dual dynamic high-gain scaling based controller and observer) cases and is shown to enable efficient computation of non-conservative bounds with reduced algebraic complexity. The efficacy of the approach is demonstrated through simulation studies. © 2022 Elsevier B.V. Chen, Y., Nie, T., Wu, Z. The stochastic maximum principle for relaxed control problem with regime-switching (2022) 169, art. no. 105391, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139592965&doi=10.1016%2fj.sysconle.2022.105391&partnerID=40&md5=c869172ea5b80ea74c632ac2b1dc9a4f DOI: 10.1016/j.sysconle.2022.105391 AFFILIATIONS: School of Mathematics, Shandong University, Shandong Province, Jinan, 250100, China ABSTRACT: We study a stochastic relaxed control problem with regime-switching, in which the control enters both the drift and the diffusion coefficients. The goal is to establish the stochastic maximum principle and verification theorem for this problem with the convex variational method. A backward stochastic differential equation (BSDE) with regime-switching is given as the adjoint equation whose martingale terms are generated by both the Brownian motion and the Markov chain. A linear quadratic example in relaxed formulation is also solved explicitly. © 2022 Elsevier B.V. Sun, Y., Li, H., Zhang, H. Mixed optimal control for discrete-time stochastic systems with random coefficients (2022) 169, art. no. 105383, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139274934&doi=10.1016%2fj.sysconle.2022.105383&partnerID=40&md5=d787e05fa1d5fad629cb272f219edcb0 DOI: 10.1016/j.sysconle.2022.105383 AFFILIATIONS: College of Electrical Engineering and Automation, Shandong University of Science and Technology, Qingdao, 266590, China; Qingdao Borsen Intelligent Technology Co., Ltd., Qingdao, 266590, China ABSTRACT: This paper is concerned with the problem of mixed optimal control for discrete-time systems with random coefficients where “mixed” means that there are two controllers: the deterministic controller and the random controller. Different from previous works, random coefficients and controllers with different information structures arise simultaneously in the optimal control problem, which lead to large difficulty. Using decoupling technique to solve the forward and backward stochastic difference equations, the necessary and sufficient conditions for the solvability of optimal control problem are given. An explicit expression of the optimal control strategies is derived based on a stochastic Riccati-type equation, which is new to the best of knowledge. Finally, a pension management problem is solved with the obtained theoretical results. © 2022 Elsevier B.V. Meng, T., Lin, Z. Leader-following almost output consensus for discrete-time heterogeneous multi-agent systems in the presence of external disturbances (2022) 169, art. no. 105380, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139069461&doi=10.1016%2fj.sysconle.2022.105380&partnerID=40&md5=576544be69975d729c2061264711b2ea DOI: 10.1016/j.sysconle.2022.105380 AFFILIATIONS: Charles L. Brown Department of Electrical and Computer Engineering, University of Virginia, P.O. Box 400743, Charlottesville, VA 22904-4743, United States ABSTRACT: In this paper, we consider the problem of leader-following almost output consensus for discrete-time multi-agent systems with heterogeneous follower agents. Conditions on agent dynamics, the communication topology and how the disturbance enters the agent dynamics are established under which leader-following almost output consensus can be achieved, that is, the leader-following output consensus can be reached with any pre-specified level of accuracy and the effect of the disturbance on the leader-following consensus can be attenuated to any pre-specified level. A family of state feedback consensus protocols are constructed by using the low gain feedback design technique and a modified discrete-time Riccati equation. These consensus protocols are shown to achieve leader-following almost output consensus. Additional conditions are identified under which output feedback results are established. Simulation results demonstrate the effectiveness of the proposed consensus protocols. © 2022 Elsevier B.V. Anantharam, V. Reversible Markov decision processes and the Gaussian free field (2022) . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139040294&doi=10.1016%2fj.sysconle.2022.105382&partnerID=40&md5=02abb8cbca78178dddd76003db67e2b9 DOI: 10.1016/j.sysconle.2022.105382 AFFILIATIONS: EECS Department, University of California, Berkeley, CA 94720, United States ABSTRACT: A Markov decision problem is called reversible if the stationary controlled Markov chain is reversible under every stationary Markovian strategy. A natural application in which such problems arise is in the control of Metropolis–Hastings type dynamics. We characterize all discrete time reversible Markov decision processes with finite state and action spaces. We show that the policy iteration algorithm for finding an optimal policy can be significantly simplified in Markov decision problems of this type. We also highlight the relation between the finite time evolution of the accrual of reward and the Gaussian free field associated to the controlled Markov chain. © 2022 Elsevier B.V. Budhiraja, A., Waterbury, A. Empirical measure large deviations for reinforced chains on finite spaces (2022) 169, art. no. 105379, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138466979&doi=10.1016%2fj.sysconle.2022.105379&partnerID=40&md5=d3c02fd9400f7c6f84145ada39ca7d88 DOI: 10.1016/j.sysconle.2022.105379 AFFILIATIONS: Department of Statistics and Operations Research, University of North Carolina at Chapel Hill, Hanes Hall, Chapel Hill, NC 27599, United States; Department of Statistics and Applied Probability, South Hall, University of California, Santa Barbara, CA 93106, United States ABSTRACT: Let A be a transition probability kernel on a finite state space Δo={1,…,d} such that A(x,y)>0 for all x,y∈Δo. Consider a reinforced chain given as a sequence {Xn,n∈N0} of Δo-valued random variables, defined recursively according to, [Formula presented] We establish a large deviation principle for {Ln,n∈N}. The rate function takes a strikingly different form than the Donsker–Varadhan rate function associated with the empirical measure of the Markov chain with transition kernel A and is described in terms of a novel deterministic infinite horizon discounted cost control problem with an associated linear controlled dynamics and a nonlinear running cost involving the relative entropy function. Proofs are based on an analysis of time-reversal of controlled dynamics in representations for log-transforms of exponential moments, and on weak convergence methods. © 2022 Elsevier B.V. Ortega, R., Romero, J.G., Aranovskiy, S. A new least squares parameter estimator for nonlinear regression equations with relaxed excitation conditions and forgetting factor (2022) 169, art. no. 105377, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138454284&doi=10.1016%2fj.sysconle.2022.105377&partnerID=40&md5=87c9ee93c2bebae960a2996b75de3a64 DOI: 10.1016/j.sysconle.2022.105377 AFFILIATIONS: Departamento Académico de Sistemas Digitales, ITAM, Progreso Tizapán 1, Ciudad de México, 01080, Mexico; Department of Control Systems and Robotics, ITMO University, Kronverkskiy av. 49, Saint Petersburg, 197101, Russian Federation; Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong; IETR–CentaleSupélec, Avenue de la Boulaie, Cesson-Sévigné, 35576, France ABSTRACT: In this note a new high performance least squares parameter estimator is proposed. The main features of the estimator are: (i) global exponential convergence is guaranteed for all identifiable linear regression equations; (ii) it incorporates a forgetting factor allowing it to preserve alertness to time-varying parameters; (iii) thanks to the addition of a mixing step it relies on a set of scalar regression equations ensuring a superior transient performance; (iv) it is applicable to nonlinearly parameterized regressions verifying a monotonicity condition and to a class of systems with switched time-varying parameters; (v) it is shown that it is bounded-input-bounded-state stable with respect to additive disturbances; (vi) continuous and discrete-time versions of the estimator are given. The superior performance of the proposed estimator is illustrated with a series of examples reported in the literature. © 2022 Elsevier B.V. Jaiswal, J., Berger, T., Tomar, N.K. Partial impulse observability of linear descriptor systems (2022) 168, art. no. 105352, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85138440985&doi=10.1016%2fj.sysconle.2022.105352&partnerID=40&md5=cb25b3f5d9a4fb538f1a76f61fe8fd43 DOI: 10.1016/j.sysconle.2022.105352 AFFILIATIONS: Department of Mathematics, Indian Institute of Technology Patna, India; Universität Paderborn, Institut für Mathematik, Warburger Str. 100, Paderborn, 33098, Germany ABSTRACT: A research paper in this journal vol. 61, no. 3, pp. 427–434, 2012, by M. Darouach, provides a functional observer design for linear descriptor systems under the partial impulse observability condition. The observer design is correct, but there was a flaw in the algebraic criterion characterizing partial impulse observability. In the present paper, we derive a novel characterization of partial impulse observability in terms of a simple rank condition involving the system coefficient matrices and an alternative characterization in terms of the Wong sequences. © 2022 Elsevier B.V. Ryan, E.P. A note on minimum time–energy control (2022) 168, art. no. 105374, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85137769824&doi=10.1016%2fj.sysconle.2022.105374&partnerID=40&md5=6dea08ec36aab56bc4705411d9ec12fe DOI: 10.1016/j.sysconle.2022.105374 AFFILIATIONS: Department of Mathematical Sciences, University of Bath, Bath, BA2 7AY, United Kingdom ABSTRACT: Elementary observations on a free-end-time problem of minimizing a functional of the form u↦∫0tuL(u(t))dt, over controls t↦u(t)∈U, U a convex, compact neighbourhood of 0∈Rm, are provided in the context of systems ẋ=f(x,u) with prescribed initial and terminal states: x(0)=ξ and x(tu)=0. Conditions on f and L are identified which are sufficient for existence and continuity of minimizers. For m=1, U=[−1,1] and [Formula presented] (reflecting a twofold performance objective with equal weight placed on transition time and energy expenditure), an exposition of aspects of the problem is given in the case of integrator chains. © 2022 Zeng, S., Li, J.-S. An operator theoretic approach to linear ensemble control (2022) 168, art. no. 105350, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85137172640&doi=10.1016%2fj.sysconle.2022.105350&partnerID=40&md5=9ce9431800eacc7cd8e7324aa952dd97 DOI: 10.1016/j.sysconle.2022.105350 AFFILIATIONS: Department of Electrical and Systems Engineering, Washington University, St. LouisMO 63130, United States ABSTRACT: In this paper, we revisit the original least squares formulation of the ensemble control problem. Based on new considerations, we are able to resolve the longstanding problem of formulating general, and easily verifiable conditions for an ensemble to be controllable in the least-squares sense. The key is to take a purely operator theoretic approach from the very beginning, i.e. to study the ensemble control problem by virtue of the associated Fredholm integral equation. By establishing a direct connection to a recently introduced moment-based approach, the theoretical question of least-squares ensemble controllability is eventually settled. In the second part, we take the very same integral operator theoretic approach to consider the equally longstanding problem of synthesizing inputs that realize a desired steering between two ensemble states. By means of a suitable discretization of the integral operator, we obtain a computational procedure to synthesize control signals that steer ensembles in both a robust and minimum energy fashion. This yields a unified framework for the ensemble control of linear systems. © 2022 Elsevier B.V. Lima, T.A., Madeira, D.D.S., Viana, V.V., Oliveira, R.C.L.F. Static output feedback stabilization of uncertain rational nonlinear systems with input saturation (2022) 168, art. no. 105359, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136707495&doi=10.1016%2fj.sysconle.2022.105359&partnerID=40&md5=238e4d4aacfbcf41b4bd94a9d398048c DOI: 10.1016/j.sysconle.2022.105359 AFFILIATIONS: ICTEAM, UCLouvain, 4 Av. G. Lemaître, Louvain-la-Neuve, 1348, Belgium; Department of Electrical Engineering, Federal University of Ceará, CE, Fortaleza, Brazil; School of Electrical and Computer Engineering, University of Campinas – UNICAMP, SP, Campinas, 13083-852, Brazil ABSTRACT: In this paper, the notion of robust strict QSR-dissipativity is applied to solve the static output feedback control problem for a class of continuous-time nonlinear rational systems subject to input saturation and bounded parametric uncertainties. A local dissipativity condition is combined with generalized sector conditions to formulate the synthesis of a stabilizing controller in terms of linear matrix inequalities. Furthermore, an iterative algorithm based on linear matrix inequalities is proposed in order to compute the feedback gain matrix that maximizes the estimate of the closed-loop region of attraction. Numerical examples are provided to illustrate the applicability of this new approach in examples borrowed from the literature. © 2022 Elsevier B.V. Rodríguez-Cortés, H., Velasco-Villa, M. A new geometric trajectory tracking controller for the unicycle mobile robot (2022) 168, art. no. 105360, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136609986&doi=10.1016%2fj.sysconle.2022.105360&partnerID=40&md5=22343d05ec822578e662ea78d2182528 DOI: 10.1016/j.sysconle.2022.105360 AFFILIATIONS: Sección de Mecatrónica, Departamento de Ingeniería Eléctrica, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Avenida Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, CP, Ciudad de México, 07360, Mexico ABSTRACT: This work proposes a geometric controller to solve the trajectory tracking problem for a differential drive mobile robot. The proposed control design exploits the properties of the mobile robot attitude configuration space and the cascade structure of the translational and rotational kinematic models. It is formally proven, through Lyapunov arguments, that the closed-loop error dynamics is almost globally asymptotically stable. Numerical simulation results illustrate the performance of the proposed control algorithm. © 2022 Elsevier B.V. An, B., Huang, B., Zou, Y., Chen, F., Meng, Z. Distributed optimization for uncertain nonlinear interconnected multi-agent systems (2022) 168, art. no. 105364, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136158025&doi=10.1016%2fj.sysconle.2022.105364&partnerID=40&md5=176372d29cdd7ead4edc9b2719d7806a DOI: 10.1016/j.sysconle.2022.105364 AFFILIATIONS: School of Control Engineering, Northeastern University at Qinhuangdao, Qinhuangdao, 066004, China; School of Automation and Electrical Engineering, University of Science and Technology Beijing, Beijing, 100083, China; Institute of Artificial Intelligence, University of Science and Technology Beijing, Beijing, 100083, China; State Key Laboratory of Synthetical Automation for Process Industries, Northeastern University, Shenyang, 110004, China; Department of Precision Instrument, Tsinghua University, Beijing, 100084, China ABSTRACT: Distributed optimization for uncertain nonlinear interconnected multi-agent systems is considered in this paper. The objective is to design distributed algorithms by using local information such that all the agents’ outputs converge to the global optimal output. The problem is challenging due to unknown modeling uncertainties and nonlinear interconnections. First, a distributed algorithm composed of a distributed state observer and a distributed optimal output observer is presented for heterogeneous outputs. Next, it is shown that the objective can be achieved by employing solely a distributed optimal output observer if the agents’ outputs are homogeneous. Finally, the algorithms’ effectiveness is validated by an electrical power system composed of four-machine subsystems. © 2022 Elsevier B.V. Guan, Y., Yang, H., Jiang, B. Fault tolerant time optimization for a class of time-varying switched infinite dimensional linear systems (2022) 168, art. no. 105361, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136085968&doi=10.1016%2fj.sysconle.2022.105361&partnerID=40&md5=165a4c81b0c45494448f51a91b7e50c6 DOI: 10.1016/j.sysconle.2022.105361 AFFILIATIONS: College of Automation Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China ABSTRACT: This paper addresses the issue of finding the optimal switching times for the time-varying switched infinite dimensional linear system with discrete faults that lead to the deviation of the actual switching signal from the normal one. A robust fault tolerant time optimization scheme based on an equivalent time transformation and a min–max mechanism is proposed to obtain the upper bound of optimal values of cost functional of all possible discrete faults. For any detectable discrete fault, an active fault tolerant time optimization scheme equipped with a switching detection technique and a gradient descent algorithm is presented to minimize every post-fault cost functional, which reduces the conservation of the robust one. © 2022 Bashirov, A.E., Ahmadova, A. Partial observability of stochastic semilinear systems (2022) 168, art. no. 105348, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135956774&doi=10.1016%2fj.sysconle.2022.105348&partnerID=40&md5=2c14be656d7318587544d9e385380fa8 DOI: 10.1016/j.sysconle.2022.105348 AFFILIATIONS: Department of Mathematics, Eastern Mediterranean University Gazimagusa, Mersin 10, Turkey; Department of Mathematics, University of Duisburg–Essen, Essen, Germany ABSTRACT: In this article, we consider an Itô stochastic semilinear differential equation with unknown initial state and a linear observation system. It is proved that under a certain condition on the observability Gramian, the initial state of the equation can be recovered. This result is demonstrated by an example. © 2022 Elsevier B.V. Aranovskiy, S., Ushirobira, R., Efimov, D., Wang, J. Accelerated convergence with improved robustness for discrete-time parameter estimation (2022) 168, art. no. 105344, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135940259&doi=10.1016%2fj.sysconle.2022.105344&partnerID=40&md5=a9e3da8a1a5b3a8e296493a4d9e053d5 DOI: 10.1016/j.sysconle.2022.105344 AFFILIATIONS: CentaleSupélec –IETR, Avenue de la Boulaie, Cesson-Sévigné, 35576, France; Inria, Univ. Lille, CNRS, UMR 9189 - CRIStAL, Lille, F-59000, France; Hangzhou Dianzi University, Hangzhou, China ABSTRACT: The dynamic regressor extension and mixing (DREM) method provides a fixed-time converging parameter estimator for a persistently excited regressor under bounded measurement noises. This note aims to develop this approach for cases with weaker excitation and regressor constraints. Several nonlinear estimation schemes with fixed-time convergence rates and improved measurement noise robustness properties are proposed here. © 2022 Elsevier B.V. Hao, N., He, F., Xie, C., Tian, C., Yao, Y. Nonlinear observability analysis of multi-robot cooperative localization (2022) 168, art. no. 105340, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135849522&doi=10.1016%2fj.sysconle.2022.105340&partnerID=40&md5=a1357e2fbda71a2b77d68a23d2ba5053 DOI: 10.1016/j.sysconle.2022.105340 AFFILIATIONS: School of Astronautics, Harbin Institute of Technology, Harbin, 150000, China ABSTRACT: In this paper, the observability property of relative position-based cooperative localization is investigated by using spectral graph theory. First, a directed graph, called Extended Relative Measurement Graph (ERMG), is constructed in which all influencing factors of observability are integrated. Then, the rank equivalence is established between the nonlinear observability matrix and the configuration matrix associated with a reduced ERMG. Then, a necessary and sufficient observability condition is proved. Moreover, an analytic relation is derived by which the configuration matrix can be directly attained according to fundamental cycles of a reduced ERMG. Then, it is shown that the observability is uniquely determined by the number and placement of fundamental cycles in a reduced ERMG. The minimum number of fundamental cycles required to guarantee an n-robot system observable is given. Additionally, a sufficient condition is provided by which reduced ERMGs can be designed to enable an n-robot system observable. Finally, a graph-based observability checking algorithm is developed which greatly improves the computation efficiency. Some illustrative examples are presented to validate the theoretical results. © 2022 Elsevier B.V. Ren, H.-J., Guo, B.-Z. Uniform exponential stability of semi-discrete scheme for observer-based control of 1-D wave equation (2022) 168, art. no. 105346, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135804686&doi=10.1016%2fj.sysconle.2022.105346&partnerID=40&md5=6871cfdb9934a9ea6d99adefdb4bbaaa DOI: 10.1016/j.sysconle.2022.105346 AFFILIATIONS: School of Mathematics and Physics, North China Electric Power University, Beijing, 102206, China; Academy of Mathematics and Systems Science, Academia Sinica, Beijing, 100190, China ABSTRACT: In this paper, we consider the uniformly exponential stability of a semi-discretized coupled system generated by a 1-D wave equation under a stabilizing output feedback control. Since the control and observation are non-collocated, we first design an observer to recover the state. The closed-loop system under the observer-based feedback is composed of a two coupled wave equations. First, we transform the closed-loop system into an equivalent system by order reduction method, and the transformed system is shown to be exponentially stable by constructing a suitable Lyapunov function. As a consequence, two equivalent semi-discrete finite difference schemes are developed corresponding to the transformed system and original coupled system. Parallel to the proof of the continuous counterpart, the Lyapunov function is constructed to prove the uniformly exponential stability of the semi-discrete scheme for the transformed system, which leads to the uniformly exponential stability of the semi-discrete scheme for the original coupled system. The weak convergence of the discrete solution to the continuous counterpart is also briefly presented. © 2022 Elsevier B.V. Bako, L., Ndiaye, S., Blanco, E. An interval-valued recursive estimation framework for linearly parameterized systems (2022) 168, art. no. 105345, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135716603&doi=10.1016%2fj.sysconle.2022.105345&partnerID=40&md5=024a27d58a952c118d916a376031e6b8 DOI: 10.1016/j.sysconle.2022.105345 AFFILIATIONS: Univ Lyon, Ecole Centrale Lyon, INSA Lyon, Université Claude Bernard Lyon 1, CNRS, Ampère, UMR 5005, Ecully, 69130, France ABSTRACT: This paper proposes a recursive interval-valued estimation framework for identifying the parameters of linearly parameterized systems which may be slowly time-varying. It is assumed that the model error (which may consist in measurement noise or model mismatch or both) is unknown but lies at each time instant in a known interval. In this context, the proposed method relies on bounding the error generated by a given reference point-valued recursive estimator, for example, the well-known recursive least squares algorithm. We discuss the trade-off between computational complexity and tightness of the estimated parametric interval. © 2022 Elsevier B.V. Pham, T.H., Vu, N.M.T., Prodan, I., Lefèvre, L. A combined Control by Interconnection—Model Predictive Control design for constrained Port-Hamiltonian systems (2022) 167, art. no. 105336, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135949669&doi=10.1016%2fj.sysconle.2022.105336&partnerID=40&md5=997da4462d54ecf64d6e8c33356d2859 DOI: 10.1016/j.sysconle.2022.105336 AFFILIATIONS: Laboratory of Signals and Systems (L2S), CNRS, Centrale Supélec, Gif-sur-Yvette, 91190, France; Univ. Grenoble Alpes, Grenoble INP, LCIS, Valence, 26000, France; École Polytechnique Féderale de Lausanne (EPFL), Swiss Plasma Center (SPC), Lausanne, CH-1015, Switzerland ABSTRACT: This paper proposes a Control by Interconnection design, for a class of constrained Port-Hamiltonian systems, which is based on an associated Model Predictive Control optimization problem. This associated optimization problem allows to consider both state and input constraints simultaneously. Based on the first order Karush–Kuhn–Tucker optimality condition, the primal–dual gradient method is then used to build a passive feedback controller, derived from the MPC-induced optimization problem. The resulting passive controller is coupled with the original Port-Hamiltonian system through a power-preserving interconnection, in order to guarantee both the closed-loop stability and constraints satisfaction, but not the optimality anymore. Comments on parameters tuning for the proposed control design, together with validations of the approach through simulations first on a linear LC circuit, then on a nonlinear Permanent Magnet Synchronous Motor and comparisons with a classical MPC design, are provided to discuss the effectiveness of the approach. © 2022 The Author(s) Parkinson, A. Linear programming based optimality conditions and approximate solution of a deterministic periodic optimal control problem in discrete time (2022) 167, art. no. 105338, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135521477&doi=10.1016%2fj.sysconle.2022.105338&partnerID=40&md5=f415e6113610c9ca21e5154b3fc983ed DOI: 10.1016/j.sysconle.2022.105338 AFFILIATIONS: Department of Mathematics and Statistics, Macquarie University, Sydney, Australia ABSTRACT: This paper is focused on a discrete time periodic optimal control problem. We establish linear programming based optimality conditions and present a method for the construction of near optimal controls. A numerical example is included to demonstrate the results. © 2022 Elsevier B.V. Michos, G., Baldivieso-Monasterios, P.R., Konstantopoulos, G.C. Distributed economic nonlinear MPC for DC Micro-Grids with inherent bounded dynamics and coupled constraints (2022) 167, art. no. 105327, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135112847&doi=10.1016%2fj.sysconle.2022.105327&partnerID=40&md5=441d756e1f86079cdef80afcc2d5a5e8 DOI: 10.1016/j.sysconle.2022.105327 AFFILIATIONS: Department of Automatic Control & Systems Engineering, University of Sheffield, Mappin Street, Sheffield, S1 3JD, United Kingdom; Department of Electrical and Computer Engineering, University of Patras, Rion, Patras, 26500, Greece ABSTRACT: This paper proposes a hierarchical control scheme for DC Micro-Grids (MGs) composed of distributed energy resource (DER) units, active loads, and coupled constraints, that incorporates different control levels to achieve economic operation and coupled constraint satisfaction at all times. All loads are considered as constant power loads (CPLs), which are known to lead to instability due to the negative impedance characteristics. To this end, firstly an improved version of the recently developed sl-PI controller is introduced in the primary level to provide boundedness and local stability of the dynamics. The supervisory controller solves an economic optimisation problem to compute voltage setpoints and at a lower control layer the system is driven to those setpoints, by utilising a distributed nonlinear MPC setup with non-iterative, neighbour-to-neighbour communication framework. A rigorous analysis on the system robustness to uncertainties in the exchanged information and bounded load variations is provided, and recursive feasibility and stability of each subsystem is analytically proven for the first time, according to the authors’ knowledge. Finally, we demonstrate the proposed controller with the aid of simulated scenarios for a DC MG with multiple DER units and CPLs. © 2022 Elsevier B.V. Dzhafarov, V., Büyükköroğlu, T. On one inner point algorithm for common Lyapunov functions (2022) 167, art. no. 105315, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134895910&doi=10.1016%2fj.sysconle.2022.105315&partnerID=40&md5=406c8458890a642fb1844ebdfce185c0 DOI: 10.1016/j.sysconle.2022.105315 AFFILIATIONS: Department of Mathematics, Faculty of Science, Eskişehir Technical University, Eskişehir, 26470, Turkey ABSTRACT: In this paper, we consider the problem of existence and evaluation of common quadratic Lyapunov functions for a finite number of matrices. For this purpose, an inner point algorithm is proposed. The technique is based on Khalil (1982), where an algorithm is given which determines the diagonal stability of a matrix A. We obtain a necessary and sufficient condition for the existence and give an efficient algorithm which gives common solution in the case of existence and negative answer after a few iterations in the case of non existence. A number of examples are presented verifying the fast speed and efficiency of the obtained results. © 2022 Elsevier B.V. Liu, W.-W., Paunonen, L., Wang, J.-M. Robust output regulation of a thermoelastic system (2022) 167, art. no. 105309, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134578607&doi=10.1016%2fj.sysconle.2022.105309&partnerID=40&md5=2a23cc0bc19081b599741f1874c9a5d9 DOI: 10.1016/j.sysconle.2022.105309 AFFILIATIONS: School of Automation, Beijing Institute of Technology, Beijing, 100081, China; Department of Mathematics and Statistics, Tampere University, Tampere, 33101, Finland; School of Mathematics and Statistics & Key Laboratory of Mathematical Theory and Computation in Information Security, Beijing Institute of Technology, Beijing, 100081, China ABSTRACT: In this paper, we consider the robust output regulation problem for the thermoelastic system where the boundary control input and the output are located at the left end of the wave equation and the disturbance input is located at the right end of the heat equation. We formulate the system as a boundary control system and prove that it is impedance passive and well-posed. We design a finite-dimensional controller based on the internal model principle and show that the controller can achieve robust output tracking and disturbance rejection. The numerical simulations demonstrate that the finite-dimensional dynamic error feedback controller can make the output track the reference signal asymptotically and the state of the closed-loop system is bounded. © 2022 Elsevier B.V. Tello, I.F.Y., Vande Wouwer, A., Coutinho, D. Observer design for multivariable transport-reaction systems based on spatially distributed measurements (2022) 167, art. no. 105323, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134538878&doi=10.1016%2fj.sysconle.2022.105323&partnerID=40&md5=5c4cd14808f2e495244ed73ef408e7ac DOI: 10.1016/j.sysconle.2022.105323 AFFILIATIONS: Systems, Estimation, Control, and Optimization (SECO), University of Mons, Belgium; Postgraduate Program in Engineering of Automation and Systems, Federal University of Santa Catarina, Brazil; Department of Electronics, Power Electrical and Mechatronics Engineering, Campus ATE, Technological University of Peru, Peru ABSTRACT: This paper is concerned with the design of observers for a class of one-dimensional multi-state transport-reaction systems considering distributed in-domain measurements over the spatial domain. A design based on the Lyapunov method is proposed for the stabilization of the estimation error dynamics. The approach uses positive definite matrices to parameterize a class of Lyapunov functionals that are positive in the Lebesgue space of integrable square functions. Thus, the stability conditions can be expressed as a set of LMI constraints which can be solved numerically using sum of squares (SOS) and standard semi-definite programming (SDP) tools. In order to evaluate the proposed methodology, a state observer is designed to estimate the variables of a nonisothermal tubular reactor model. Numerical simulations are presented to demonstrate the potentials of the proposed observer. © 2022 Elsevier B.V. Badri, V. Global observer for Lotka–Volterra systems (2022) 167, art. no. 105319, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134290817&doi=10.1016%2fj.sysconle.2022.105319&partnerID=40&md5=d760a7b661da21de501b0db7e08827f7 DOI: 10.1016/j.sysconle.2022.105319 AFFILIATIONS: Faculty of Electrical Engineering, Shahid Beheshti University, Tehran, 16589-53571, Iran ABSTRACT: This paper develops a new approach to the long-standing problem of global asymptotic positive observer design for n-dimensional Lotka–Volterra (LV) systems. In this approach, instead of the state error dynamics, the notion of state ratio dynamics is used by exploiting the positivity property of the LV systems. A novel class of observers is proposed and the global asymptotic convergence of such observers is studied via a well-known logarithmic Lyapunov function. The obtained convergence conditions of the proposed observer are formulated as a linear matrix inequality (LMI), which can be used to determine the unknown parameters of the observer. This design procedure is modified for state estimation of time-varying LV systems, too. The applicability of the proposed method is investigated through two numerical examples. © 2022 Elsevier B.V. Lin, B., Yao, W., Cao, M. On Wilson's theorem about domains of attraction and tubular neighborhoods (2022) 167, art. no. 105322, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134243830&doi=10.1016%2fj.sysconle.2022.105322&partnerID=40&md5=0a7d40ab91b61ddffabdd388493b2129 DOI: 10.1016/j.sysconle.2022.105322 AFFILIATIONS: Faculty of Science and Engineering, University of Groningen, Netherlands ABSTRACT: In this paper, we show that the domain of attraction of a compact asymptotically stable submanifold in a finite-dimensional smooth manifold of an autonomous system is homeomorphic to the submanifold's tubular neighborhood. The compactness of the submanifold is crucial, without which this result is false; two counterexamples are provided to demonstrate this. © 2022 The Author(s) Darouach, M., Fernando, T. Optimal discrete-time unbiased filtering for systems with unknown inputs (2022) 166, art. no. 105305, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133940690&doi=10.1016%2fj.sysconle.2022.105305&partnerID=40&md5=348fdedce6bfab7470c8a4fcc915a32c DOI: 10.1016/j.sysconle.2022.105305 AFFILIATIONS: Centre de Recherche en Automatique de Nancy (CRAN UMR-7039, CNRS), université de Lorraine, IUT de Longwy, 186 rue de Lorraine, Lorraine, Cosnes et Romain, 54400, France; Department of Electrical, Electronic and Computer Engineering, University of Western Australia, 35 Stirling Highway, Crawley, 6009, WA, Australia ABSTRACT: This paper concerns the H∞ functional filtering design problem for discrete-time systems with unknown inputs. Our interest is focused on the unbiased filtering satisfying the H∞ performance. First the unbiasedness conditions of the estimation error are presented. The dynamic of this error is dependent on the present and future values of the noise. Different cases are presented, the first one is based on the introduction of an algebraic constraint leading to the dynamic error dependent only on the present noise, the second case is more general and can be treated by modifying the performance index or by using the descriptor systems formulation. The conditions of the existence of an unbiased filter are presented and the designs of the different filters, based on the bounded real lemma, are given in the form of the linear matrix inequalities (LMI). The presented approach unifies the design of functional, reduced-order and full-order filters for discrete-time systems. Three numerical examples are presented to illustrate the approach described in the paper and shows the performance of the proposed functional filter. © 2022 Zhang, K.-K., Zhou, B., Hou, M., Duan, G.-R. Prescribed-time control of high-order nonholonomic systems in chained form by time-varying feedback (2022) 166, art. no. 105307, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133652914&doi=10.1016%2fj.sysconle.2022.105307&partnerID=40&md5=7ae1132b6de24dcd581b791a8ef062ec DOI: 10.1016/j.sysconle.2022.105307 AFFILIATIONS: Center for Control Theory and Guidance Technology, Harbin Institute of Technology, Harbin, 150001, China ABSTRACT: In this paper, the prescribed-time control problem for a class of high-order nonholonomic systems is investigated. With the aid of a novel state transformation, the nonholonomic systems are decoupled. Further, a time-varying high-gain feedback controller is constructed by backstepping. It is shown that the proposed control law can achieve the prescribed-time convergence for high-order nonholonomic systems and the controller is bounded. Numerical examples verify the effectiveness of the method proposed in this paper. © 2022 Elsevier B.V. Chen, T., Song, Y., Wu, Z. The maximum principle for stochastic control problem with Markov chain in progressive structure (2022) 166, art. no. 105303, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133426226&doi=10.1016%2fj.sysconle.2022.105303&partnerID=40&md5=582c534d59ae58484e0185bfa2ebb9c7 DOI: 10.1016/j.sysconle.2022.105303 AFFILIATIONS: Zhongtai Securities Institute for Financial Studies, Shandong University, Jinan, 250100, China; School of Mathematics, Shandong University, Jinan, 250100, China ABSTRACT: In this paper, we obtain the stochastic maximum principle for progressive optimal control of the model driven by Brownian motions and Markov chain. The maximum principle in progressive structure is essentially different from that in the classical case. Our maximum principle has two parts, including continuous part and jump part, which are used to characterize the characteristics of control at continuous time and jump time respectively. This shows that the progressive structure can better describe the optimal control of stochastic system with jumps. Moreover, we give an LQ example to show that the cost functional can indeed get a smaller value in progressive structure. © 2022 Hosseinalizadeh, T., Turkmen, F., Monshizadeh, N. Private computation of polynomials over networks (2022) 166, art. no. 105291, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85132531250&doi=10.1016%2fj.sysconle.2022.105291&partnerID=40&md5=c7cccbc492ae79b3c275ba94b4b32f5c DOI: 10.1016/j.sysconle.2022.105291 AFFILIATIONS: Engineering and Technology Institute, University of Groningen, Netherlands; Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Netherlands ABSTRACT: This study concentrates on preserving privacy in a network of agents where each agent seeks to evaluate a general polynomial function over the private values of her immediate neighbors. We provide an algorithm for the exact evaluation of such functions while preserving privacy of the involved agents. The solution is based on a reformulation of polynomials and adoption of two cryptographic primitives: Paillier as a Partially Homomorphic Encryption scheme and multiplicative–additive secret sharing. The provided algorithm is fully distributed, lightweight in communication, robust to dropout of agents, and can accommodate a wide class of functions. Moreover, system theoretic and secure multi-party conditions guaranteeing the privacy preservation of an agent's private values against a set of colluding agents are established. The theoretical developments are complemented by numerical investigations illustrating the accuracy of the algorithm and the resulting computational cost. © 2022 The Author(s) Das, A., Chaffey, T., Sepulchre, R. Oscillations in mixed-feedback systems (2022) 166, art. no. 105289, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131936993&doi=10.1016%2fj.sysconle.2022.105289&partnerID=40&md5=cdb5d6249e1d6709bcf15f3e2c73fb7a DOI: 10.1016/j.sysconle.2022.105289 AFFILIATIONS: University of Cambridge, Department of Engineering, Trumpington Street, Cambridge, CB2 1PZ, United States ABSTRACT: A new method is presented for the analysis of limit cycle oscillations in mixed-feedback systems. The calculation of the limit cycle is reformulated as the zero finding of a mixed-monotone relation, that is, of the difference of two maximally monotone relations. The problem can then be solved efficiently by borrowing existing algorithms that minimize the difference of two convex functions. The potential of the method is illustrated on the classical Van der Pol oscillator. © 2022 The Author(s) Zhao, S., Chen, X.-M., Liu, Y. Asymptotic properties of dual averaging algorithm for constrained distributed stochastic optimization (2022) 165, art. no. 105252, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131219143&doi=10.1016%2fj.sysconle.2022.105252&partnerID=40&md5=438ee09fd226358f5f2e74c32d2fe831 DOI: 10.1016/j.sysconle.2022.105252 AFFILIATIONS: School of Mathematical Sciences, Dalian University of Technology, Dalian, 116024, China ABSTRACT: Considering the constrained stochastic optimization problem over a time-varying random network, where the agents are to collectively minimize a sum of objective functions subject to a common constraint set, we investigate asymptotic properties of a distributed algorithm based on dual averaging of gradients. Different from most existing works on distributed dual averaging algorithms that are mainly focused on their non-asymptotic properties, we prove not only almost sure convergence and rate of almost sure convergence, but also asymptotic normality and asymptotic efficiency of the algorithm. Firstly, for general constrained convex optimization problem distributed over a random network, we prove that almost sure consensus can be achieved and the estimates of agents converge to the same optimal point. For the case of linear constrained convex optimization, we show that the mirror map of the averaged dual sequence identifies the active constraints of the optimal solution with probability 1, which helps us to prove the almost sure convergence rate and then establish asymptotic normality of the algorithm. Furthermore, we also verify that the algorithm is asymptotically optimal. To the best of our knowledge, it is the first asymptotic normality result for constrained distributed optimization algorithms. Finally, a numerical example is provided to justify the theoretical analysis. © 2022 Elsevier B.V. Gramlich, D., Ebenbauer, C., Scherer, C.W. Synthesis of accelerated gradient algorithms for optimization and saddle point problems using Lyapunov functions and LMIs (2022) 165, art. no. 105271, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131143213&doi=10.1016%2fj.sysconle.2022.105271&partnerID=40&md5=b99fd762c0b1a609140fb117a1d5deb4 DOI: 10.1016/j.sysconle.2022.105271 AFFILIATIONS: Chair of Intelligent Control Systems, RWTH Aachen University, Kopernikusstrasse 16, Aachen, 52074, Germany; Chair of Mathematical Systems Theory, University of Stuttgart, Pfaffenwaldring 5a, Stuttgart, 70569, Germany ABSTRACT: This paper considers the problem of designing accelerated gradient-based algorithms for optimization and saddle-point problems. The class of objective functions is defined by a generalized sector condition. This class of functions contains strongly convex functions with Lipschitz gradients but also non-convex functions, which allows not only to address optimization problems but also saddle-point problems. The proposed design procedure relies on a suitable class of Lyapunov functions and, for a fixed convergence rate, is a convex semi-definite program in all but one scalar parameter. The proposed synthesis allows the design of algorithms that reach the performance of state-of-the-art accelerated gradient methods and beyond. © 2022 Elsevier B.V. Aalto, A., Lamoline, F., Gonçalves, J. Linear system identifiability from single-cell data (2022) 165, art. no. 105287, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131121339&doi=10.1016%2fj.sysconle.2022.105287&partnerID=40&md5=3f5339515152ea772e1b77b4f6e200f7 DOI: 10.1016/j.sysconle.2022.105287 AFFILIATIONS: Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 6 avenue du Swing, Belvaux, 4367, Luxembourg; Luxembourg Institute of Health, Department of Cancer Research, 1a-b rue Thomas Edison, Strassen, 1445, Luxembourg; University of Cambridge, Department of Plant Sciences, Downing St, Cambridge, CB2 3EA, United Kingdom ABSTRACT: In this brief article, we prove a result on identifiability of a discrete-time linear system from measurements of the mean and the covariance of the state distribution, obtained from population snapshot observations over time. We show that three time points of such measurements are sufficient for unique identifiability. This is in stark contrast to identifiability from time series data, in which case n+1 measurements are required for identifiability of an n-dimensional system. Robustness of the identifiability is investigated by numerical experiments. The work is motivated by the problem of gene regulatory network inference from single-cell data and will serve as a foundation for the development of modelling algorithms. © 2022 The Author(s) Liang, L., Yan, X., Shen, T. Global output-feedback adaptive stabilization for uncertain nonlinear systems with polynomial growth nonlinearities (2022) 165, art. no. 105269, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130595611&doi=10.1016%2fj.sysconle.2022.105269&partnerID=40&md5=74749dac1a07993174b648367f96c1c4 DOI: 10.1016/j.sysconle.2022.105269 AFFILIATIONS: School of Electrical Engineering, University of Jinan, Jinan, Shandong, 250022, China ABSTRACT: In this paper, the problem of global adaptive stabilization by smooth output-feedback is investigated for a class of uncertain nonlinear system with unmeasured states dependent growth. The highlight of the paper lies in that the growth rate with output-dependent polynomial growth and the measurement sensitivity are both unknown, or the dimension of the closed-loop system is significantly reduced. To handle these, a distinct observer with two high-gains is introduced and two dynamic high-gains are updated in the new forms. Motivated by the closely related works, we propose a systematic non-identifier based output feedback control scheme by using the idea of universal control and backstepping technique. The designed controller can globally regulate the states of the original system and the observer while maintaining global boundedness of the closed-loop system. A numerical example is given to demonstrate the effectiveness of the proposed method. © 2022 Elsevier B.V. Yang, Q., Zhang, Z., Fu, M., Cai, Q. Asymptotic convergence of a distributed weighted least squares algorithm for networked systems with vector node variables (2022) 165, art. no. 105265, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130314451&doi=10.1016%2fj.sysconle.2022.105265&partnerID=40&md5=4da7264803c1fd07a258719d9cb1f507 DOI: 10.1016/j.sysconle.2022.105265 AFFILIATIONS: School of Control Science and Engineering, Shandong University, Jinan, 250061, China; School of Electrical Engineering and Computing, The University of Newcastle, Callaghan, 2308, NSW, Australia; School of Automation, Guangdong University of Technology, Guangzhou, 510006, China ABSTRACT: This paper studies the convergence properties of a recently proposed distributed algorithm for weighted least-squares (WLS) estimation in networked systems. This algorithm is suitable for large-scale networks with a vector parameter (variable) in each node of the network. By establishing the connection between this algorithm and the celebrated Gaussian Belief Propagation (BP) algorithm for statistical learning with scalar variables, asymptotic convergence of the algorithm is established under the assumption of generalised block diagonal dominance. This result generalises the known asymptotic convergence result of the Gaussian BP algorithm for networks with scalar variables. By extending the notion of diagonal dominance to block matrices, we are able to generalise the so-called walk-sum approach for convergence analysis of the Gaussian BP algorithm to this distributed WLS algorithm and show a similar asymptotic convergence property for networks with vector parameters. The significance of our work is that it gives theoretical guarantee for the distributed WLS algorithm for a new class of large-scale networked systems with vector parameters. © 2022 Witschel, J. On output stabilizability of differential–algebraic equations (2022) 165, art. no. 105232, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129933095&doi=10.1016%2fj.sysconle.2022.105232&partnerID=40&md5=871a5744a495681d2a04c3e1dcf45ba3 DOI: 10.1016/j.sysconle.2022.105232 AFFILIATIONS: Technische Universität Ilmenau, Weimarer Straße 25, Ilmenau, 98693, Germany ABSTRACT: We study output stabilizability of differential–algebraic systems. Two different notions of stability, an asymptotic one and one based on the Lq norm of the output are compared and shown be equivalent. To introduce the use of the main concepts of output injection and the Kalman observability decomposition, we begin with a short proof of the result for the special case of ordinary differential equations. These results can then be generalized to differential–algebraic equations, which requires some further attention, especially with respect to observability. Equivalence of the two output stabilizabilities is worth knowing in its own right, and has applications for example in the context of optimal control. © 2022 Elsevier B.V. Li, M., Lestas, I., Qiu, L. Parallel feedforward compensation for output synchronization: Fully distributed control and indefinite Laplacian (2022) 164, art. no. 105250, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129762035&doi=10.1016%2fj.sysconle.2022.105250&partnerID=40&md5=e525da934b8f32b7900bd5cebfeb1580 DOI: 10.1016/j.sysconle.2022.105250 AFFILIATIONS: Department of Engineering, University of Cambridge, UK, Cambridge, CB2 1PZ, United Kingdom; Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong ABSTRACT: This work is associated with the use of parallel feedforward compensators (PFCs) for the problem of output synchronization over heterogeneous agents and the benefits this approach can provide. Specifically, it addresses the addition of stable PFCs on agents that interact with each other using diffusive couplings. The value in the application of such PFC is twofold. Firstly, it has been an issue that output synchronization among passivity-short systems requires global information for the design of controllers in the cases when initial conditions need to be taken into account, such as average consensus and distributed optimization. We show that a stable PFC can be designed to passivate a passivity-short system while its output asymptotically vanishes as its input tends to zero. As a result, output synchronization is achieved among these systems by fully distributed controls without altering the original consensus results. Secondly, in the literature of output synchronization over signed weighted graphs, it is generally required that the graph Laplacian be positive semidefinite, i.e., L≥0 for undirected graphs or L+LT≥0 for balanced directed graphs. We show that the PFC serves as output feedback to the communication graph to enhance the robustness against negative weight edges. As a result, output synchronization is achieved over a signed weighted and balanced graph, even if the corresponding Laplacian is not positive semidefinite. © 2022 The Author(s) Maupong, T.M., Rapisarda, P. State for linear discrete time-varying systems, with applications to dissipative systems (2022) 164, art. no. 105246, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129730322&doi=10.1016%2fj.sysconle.2022.105246&partnerID=40&md5=b4c35bc5e0107e43ab911de981badc2e DOI: 10.1016/j.sysconle.2022.105246 AFFILIATIONS: Faculty of Sciences, Botswana International University of Science and Technology, Botswana; Electronics and Computer Science, University of Southampton, UK, United Kingdom ABSTRACT: We study the notion of state for a class of linear discrete time-varying systems and provide a characterization of polynomial operator in the shift used to define state trajectory from both external and auxiliary trajectories. We then characterize lossless systems and show that a storage function for a dissipative system can be written as a quadratic function of the state. © 2022 Elsevier B.V. Verrelli, C.M. PI-generalizing saturated repetitive learning control for a class of nonlinear uncertain systems: Robustness w.r.t. relative degree zero or one (2022) 164, art. no. 105248, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129694196&doi=10.1016%2fj.sysconle.2022.105248&partnerID=40&md5=cb312f2481669d322f80edae3edb3ff9 DOI: 10.1016/j.sysconle.2022.105248 AFFILIATIONS: Electronic Engineering Department of “Tor Vergata” University, Via del Politecnico 1, Rome, 00133, Italy ABSTRACT: The class of single-input, single-output, nonlinear, time-invariant systems with unknown output-dependent nonlinearities, unknown parameters and relative degree ρ∈{0,1} is considered. A priori knowledge of the system includes globally Lipschitz nature of the nonlinearities and positive sign of the high-frequency gain, besides the minimum-phase property. Single-input, single-output, observable, minimum phase, linear, time-invariant systems are included as a very special case. The aim is to track, via the output error feedback only, periodic output reference signals with known period. Here we originally show that the same saturated repetitive learning control that constitutes the most natural generalization of the PI (Proportional–Integral) control, concurrently ensures the following properties for any initial condition of the system: asymptotic convergence to zero of the output tracking error is guaranteed if ρ=1; exponential convergence to zero is achieved for both the output and the input tracking errors if ρ=0. © 2022 Elsevier B.V. Khodadadian, S., Jhunjhunwala, P.R., Varma, S.M., Maguluri, S.T. On linear and super-linear convergence of Natural Policy Gradient algorithm (2022) 164, art. no. 105214, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129621464&doi=10.1016%2fj.sysconle.2022.105214&partnerID=40&md5=40b60165af67f0e3a8b8e4d152dfcc9b DOI: 10.1016/j.sysconle.2022.105214 AFFILIATIONS: H. Milton Stewart School of Industrial & Systems Engineering, Georgia Institute of Technology, Atlanta, GA 30332, United States ABSTRACT: Markov Decision Processes are classically solved using Value Iteration and Policy Iteration algorithms. Recent interest in Reinforcement Learning has motivated the study of methods inspired by optimization, such as gradient ascent. Among these, a popular algorithm is the Natural Policy Gradient, which is a mirror descent variant for MDPs. This algorithm forms the basis of several popular RL algorithms such as Natural actor–critic, TRPO, PPO, etc., and so is being studied with growing interest. It has been shown that Natural Policy Gradient with constant step size converges with a sub-linear rate of O(1/k) to the global optimal. In this paper, we present improved finite time convergence bounds, and show that this algorithm has geometric (also known as linear) asymptotic convergence rate. We further improve this convergence result by introducing a variant of Natural Policy Gradient with adaptive step sizes. Finally, we compare different variants of policy gradient methods experimentally. © 2022 Elsevier B.V. Bobtsov, A., Ortega, R., Aranovskiy, S., Cisneros, R. On-line estimation of the parameters of the windmill power coefficient (2022) 164, art. no. 105242, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129522307&doi=10.1016%2fj.sysconle.2022.105242&partnerID=40&md5=23faf12353c701161417cd34e1c6305c DOI: 10.1016/j.sysconle.2022.105242 AFFILIATIONS: Hangzhou Dianzi University (HDU), Hangzhou, 310018, China; ITMO University, St. Petersburg, 197101, Russian Federation; Instituto Tecnológico Autónomo de México, Mexico city, 01080, Mexico; CentraleSupélec, Rennes, 35576, France ABSTRACT: Wind turbines are often controlled to harvest the maximum power from the wind, which corresponds to the operation at the top of the bell-shaped power coefficient graph. Such a mode of operation may be achieved implementing an extremum seeking data-based strategy, which is an invasive technique that requires the injection of harmonic disturbances. Another approach is based on the knowledge of the analytic expression of the power coefficient function, an information usually unreliably provided by the turbine manufacturer. In this paper we propose a globally, exponentially convergent on-line estimator of the parameters entering into the windmill power coefficient function. This corresponds to the solution of an identification problem for a nonlinear, nonlinearly parameterized, underexcited system. To the best of our knowledge we have provided the first solution to this challenging, practically important, problem. © 2022 Elsevier B.V. Oliver, M., Georges, D., Prieur, C. Spatialized epidemiological forecasting applied to Covid-19 pandemic at departmental scale in France (2022) 164, art. no. 105240, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129453629&doi=10.1016%2fj.sysconle.2022.105240&partnerID=40&md5=5ec3109b18fe26245381daa7603d8f1e DOI: 10.1016/j.sysconle.2022.105240 AFFILIATIONS: Univ. Grenoble Alpes, CNRS, Grenoble INP, GIPSA-lab, Grenoble, F-38000, France; Univ. Grenoble Alpes, Inria, CNRS, Grenoble INP, LJK, Grenoble, 38000, France ABSTRACT: In this paper, we present a spatialized extension of a SIR model that accounts for undetected infections and recoveries as well as the load on hospital services. The spatialized compartmental model we introduce is governed by a set of partial differential equations (PDEs) defined on a spatial domain with complex boundary. We propose to solve the set of PDEs defining our model by using a meshless numerical method based on a finite difference scheme in which the spatial operators are approximated by using radial basis functions. Such an approach is reputed as flexible for solving problems on complex domains. Then we calibrate our model on the French department of Isère during the first period of lockdown, using daily reports of hospital occupancy in France. Our methodology allows to simulate the spread of Covid-19 pandemic at a departmental level, and for each compartment. However, the simulation cost prevents from online short-term forecast. Therefore, we propose to rely on reduced order modeling to compute short-term forecasts of infection number. The strategy consists in learning a time-dependent reduced order model with few compartments from a collection of evaluations of our spatialized detailed model, varying initial conditions and parameter values. A set of reduced bases is learnt in an offline phase while the projection on each reduced basis and the selection of the best projection is performed online, allowing short-term forecast of the global number of infected individuals in the department. The original approach proposed in this paper is generic and could be adapted to model and simulate other dynamics described by a model with spatially distributed parameters of the type diffusion–reaction on complex domains. Also, the time-dependent model reduction techniques we introduced could be leveraged to compute control strategies related to such dynamics. © 2022 Elsevier B.V. Jin, F.-F., Guo, W. Boundary stabilization of a 1-D wave equation with multi-point velocity recirculations (2022) 164, art. no. 105230, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129256205&doi=10.1016%2fj.sysconle.2022.105230&partnerID=40&md5=ed8a481891fe23b0873a697a817d2287 DOI: 10.1016/j.sysconle.2022.105230 AFFILIATIONS: School of Mathematics and Statistics, Shandong Normal University, Jinan, 250014, China; School of Statistics, University of International Business and Economics, Beijing, 100029, China ABSTRACT: This paper considers the boundary state and output feedback stabilization of a one-dimensional wave equation with in-domain velocity feedbacks/recirculations of multi-intermediate points respectively. Constructing an auxiliary control system with nonlocal terms which are the displacements at the same intermediate points, we design a state feedback controller for the original system by a two-step backstepping transformation. The resulting closed-loop of original system is proved to be well-posed and exponentially stable. Then an observer-based output feedback controller is proposed to exponentially stabilize the original system. Finally, some numerical simulations are presented to validate the theoretical results. © 2022 Elsevier B.V. Zhang, S., Tang, L., Liu, Y.-J. Output feedback control of a flexible marine riser with the top tension constraint (2022) 163, art. no. 105208, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85128757150&doi=10.1016%2fj.sysconle.2022.105208&partnerID=40&md5=7ec69b256127ab95a653bf5b047329db DOI: 10.1016/j.sysconle.2022.105208 AFFILIATIONS: College of Science, Liaoning University of Technology, Jinzhou, Liaoning, 121001, China ABSTRACT: In this paper, for the flexible marine riser system with the top tension constraint, the output feedback controller is developed to suppress the vibration of the riser. The dynamic behavior of the flexible riser is expressed by the partial differential equation (PDE). Firstly, a high-gain observer is designed to estimate unmeasurable system states. Secondly, the top tension of the riser is constrained with the aid of the logarithmic barrier Lyapunov function, and the output feedback boundary controller is developed using the direct Lyapunov method. Through rigorous mathematical analysis, the consistently bounded stability of the closed-loop system is achieved. Finally, the simulation is carried out to show that the developed control can stabilize the system with good performance under proper selection of design parameters. © 2022 Elsevier B.V. Luppi, A., De Persis, C., Tesi, P. On data-driven stabilization of systems with nonlinearities satisfying quadratic constraints (2022) 163, art. no. 105206, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127308066&doi=10.1016%2fj.sysconle.2022.105206&partnerID=40&md5=13cd527f740f6e9782f7e176fec4b181 DOI: 10.1016/j.sysconle.2022.105206 AFFILIATIONS: ENTEG, University of Groningen, Groningen, 9747 AG, Netherlands; DINFO, University of Florence, Florence, 50139, Italy ABSTRACT: In this paper, we directly design a state feedback controller that stabilizes a class of uncertain nonlinear systems solely based on input-state data collected from a finite-length experiment. Necessary and sufficient conditions are derived to guarantee that the system is absolutely stabilizable and a controller is designed. Results derived under some relaxed prior information about the system, strengthened data assumptions and perturbed data are also discussed. All the results are based on semi-definite programs that depend on input-state data only, which – once solved – directly return controllers. As such they represent end-to-end solutions to the problem of learning control from data for an important class of nonlinear systems. Numerical examples illustrate the method with different levels of prior information. © 2022 The Author(s) Heydari, R., Farrokhi, M. Robust event-triggered model predictive control of polytopic LPV systems: An input-to-state stability approach (2022) 163, art. no. 105202, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85127258395&doi=10.1016%2fj.sysconle.2022.105202&partnerID=40&md5=b655939ba94bdb2d0a065493cd6eb155 DOI: 10.1016/j.sysconle.2022.105202 AFFILIATIONS: Department of Electrical and Electronic Engineering, Iran University of Science and Technology, Tehran, Iran; Center of Excellence for Modeling and Control of Complex Systems, Iran University of Science and Technology, Tehran, Iran ABSTRACT: This paper addresses the problem of designing robust event-triggered tube-based model predictive control (TMPC) for constrained linear parameter-varying systems. The main challenge with implementing TMPC schemes in an event-triggered setup is that the assumption of feedback for all sampling times is not satisfied, which leads to an exponential growth of the predicted sets. First, a novel modification of homothetic TMPC is introduced to consider the effect of open-loop control between triggering times. At each sampling instant, the TMPC provides the maximal feasible number of open-loop steps and a sequence of control inputs, which can be applied in an open-loop fashion while satisfying the state and control constraints. Second, depending on the maximal number of open-loop steps, the triggering condition is derived based on the input-to-state stability (ISS) concept with the aim to reduce the communication traffic between sensors, controllers and actuators. Moreover, recursive feasibility and asymptotic stability of the closed-loop system are guaranteed. Simulation results demonstrate the efficacy of the proposed scheme while reducing the frequency of the update times. © 2022 Elsevier B.V. Taraba, P., Kitzing, K., Siegmund, S. Stability of linear second-order time-varying differential equations via contractive polygons (2022) 162, art. no. 105186, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126994770&doi=10.1016%2fj.sysconle.2022.105186&partnerID=40&md5=d7d2497acde1d1f6d1fef954167b929d DOI: 10.1016/j.sysconle.2022.105186 AFFILIATIONS: Fort LauderdaleFL, United States; Institute of Analysis, Faculty of Mathematics, TU Dresden, Germany ABSTRACT: A damped harmonic oscillator ẍ(t)+a1ẋ(t)+a0x(t)=0 with a0,a1>0 is known to be exponentially stable. We extend this result to time-varying positive coefficients a0(t), a1(t), t≥0, which are bounded from above and below and satisfy supt≥0a0(t)<(inft≥0a1(t))2 and we thus further extend the sufficient condition [Formula presented] by Levin (1969). Under slightly weaker assumptions we show uniform stability. © 2022 Elsevier B.V. Yang, S. A varying terminal time mean–variance model (2022) 162, art. no. 105184, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125891974&doi=10.1016%2fj.sysconle.2022.105184&partnerID=40&md5=aa09c08c31125a34642ae95dce67fdf1 DOI: 10.1016/j.sysconle.2022.105184 AFFILIATIONS: Shandong University-Zhong Tai Securities Institute for Financial Studies, Shandong University, China ABSTRACT: To improve the efficient frontier of the classical mean–variance model in continuous time, we propose a varying terminal time mean–variance model with a constraint on the mean value of the portfolio asset, which moves with the varying terminal time. Using the embedding technique from stochastic optimal control in continuous time and varying the terminal time, we determine an optimal strategy and related deterministic terminal time for the model. The results of this paper suggest that for an investment plan requires minimizing the variance with a varying terminal time. © 2022 Elsevier B.V. Du, K., Wu, Z. Social optima in mean field linear–quadratic–Gaussian models with control input constraint (2022) 162, art. no. 105174, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125501301&doi=10.1016%2fj.sysconle.2022.105174&partnerID=40&md5=4bfcdd4d7a36449e1909dc502f560881 DOI: 10.1016/j.sysconle.2022.105174 AFFILIATIONS: School of Mathematics, Shandong University, Jinan, 250100, China ABSTRACT: This paper studies linear quadratic social optimal problems with control input constraints, where both dynamics and costs involve the coupled term of states, and the diffusion terms contain control variables. In virtue of the variational method, we obtain the corresponding auxiliary stochastic control problem by introducing the limiting state-average process. Furthermore, we design a set of decentralized control strategies by using the stochastic maximum principle, which is given by a fully coupled non-linear mean-field forward–backward stochastic differential equation, and they are further shown to be asymptotically social optimality by perturbation analysis. As applications, we apply the theoretical results to deal with the optimal consumption problem and obtain the related optimal consumption strategy. © 2022 Elsevier B.V. Wakaiki, M. Stability of infinite-dimensional sampled-data systems with unbounded control operators and perturbations (2022) 162, art. no. 105170, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125491893&doi=10.1016%2fj.sysconle.2022.105170&partnerID=40&md5=2476521b88515c73f7837d37a082f0be DOI: 10.1016/j.sysconle.2022.105170 AFFILIATIONS: Department of Applied Mathematics, Graduate School of System Informatics, Kobe University, Kobe, 657-8501, Japan ABSTRACT: We analyze the robustness of the exponential stability of infinite-dimensional sampled-data systems with unbounded control operators. The unbounded perturbations we consider are the so-called Desch–Schappacher perturbations, which arise, e.g., from the boundary perturbations of systems described by partial differential equations. As the main result, we show that the exponential stability of the sampled-data system is preserved under all Desch–Schappacher perturbations sufficiently small in a certain sense. © 2022 Elsevier B.V. Li, J., Wu, Z., Liu, Y. Adaptive stabilization for an uncertain reaction–diffusion equation with dynamic boundary condition at control end (2022) 162, art. no. 105180, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125302191&doi=10.1016%2fj.sysconle.2022.105180&partnerID=40&md5=dfd95479c0f88d1aa6fb4ef035503d41 DOI: 10.1016/j.sysconle.2022.105180 AFFILIATIONS: School of Mathematics and Information Sciences, Yantai University, Yantai, 264005, China; School of Control Science and Engineering, Shandong University, Jinan, 250061, China ABSTRACT: This paper is devoted to the stabilization of a class of uncertain reaction–diffusion equations with dynamic boundary condition. Remarkably, the dynamics of boundary condition at control end are considered while unknown parameters are contained in both the intra-domain and the dynamic boundary. This greatly relaxes the restrictions on boundary dynamics and system uncertainties of the related literature where dynamic boundary condition is neglected or considered but unknown parameters are only contained in the dynamic boundary or even completely excluded from the whole system. To solve the control problem, a novel control framework is established by infinite-dimensional backstepping method combining with adaptive compensation technique based on passive identifier. Then, an adaptive state-feedback controller is explicitly constructed which guarantees that all the states of the resulting closed-loop system are bounded while those of the original system converge to zero. A simulation example is provided to validate the effectiveness of the proposed theoretical results. © 2022 Elsevier B.V. Meslem, N., Hably, A., Raïssi, T. Zonotopic unknown input state estimator for discrete-time linear systems (2022) 162, art. no. 105168, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125295238&doi=10.1016%2fj.sysconle.2022.105168&partnerID=40&md5=3c55bf055a6b42f162e329557880c3ea DOI: 10.1016/j.sysconle.2022.105168 AFFILIATIONS: Univ. Grenoble Alpes, CNRS, Grenoble INP*, GIPSA-lab, Grenoble, 38000, France; Conservatoire National des Arts et Métiers 292 Rue Saint-Martin, Paris, 75141, France ABSTRACT: In this work state estimation for unknown input discrete-time linear systems is tackled in a bounded error context. First, under the boundedness assumption on both process and measurement noise as well as on system's initial state, the estimation problem is reformulated as a reachability problem. Then, by preprocessing the set-valued expression of the general solution of the state equation and applying zonotopic set computation rules, a non-conservative and computationally tractable algorithm is proposed to characterize efficiently the solution set of this problem. Numerical examples are presented to show the performance of the proposed zonotopic unknown input state estimator. © 2022 Elsevier B.V. Jeeninga, M. Braess’ paradox for power flow feasibility and parametric uncertainties in DC power grids with constant-power loads (2022) 161, art. no. 105146, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85126138712&doi=10.1016%2fj.sysconle.2022.105146&partnerID=40&md5=d5e582d720c5182f31f25970b6697fbc DOI: 10.1016/j.sysconle.2022.105146 AFFILIATIONS: Department of Mathematical Sciences “G.L. Lagrange”, Politecnico di Torino, Torino, 10129, Italy ABSTRACT: This paper studies the power flow feasibility of DC power grids with constant-power loads. We introduce and motivate the concept of Braess’ paradox for power flow feasibility, and show that this phenomenon can occur in most practical power grids with at least two source nodes. To combat Braess’ paradox we consider bounded parametric uncertainties in the power lines, and give a simple but conservative sufficient condition to guarantee that the power flow is feasible under these parametric uncertainties. We refer to this property as strong feasibility. © 2022 Elsevier B.V. Wang, S., Wu, Z., Wu, Z.-G. The regulation controller design for linear random systems with an uncertain exosystem (2022) 161, art. no. 105150, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124453232&doi=10.1016%2fj.sysconle.2022.105150&partnerID=40&md5=ef08c0339a24607c883eff4cbe3597a8 DOI: 10.1016/j.sysconle.2022.105150 AFFILIATIONS: The State Key Laboratory of Industrial Control Technology, Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou, Zhejiang, 310027, China; The School of Mathematics and Informational Science, Yantai University, Yantai, Shandong, 264005, China; Institute of Intelligence Science and Engineering, Shenzhen Polytechnic, Shenzhen, Guangdong, 518000, China ABSTRACT: A new controller with an internal model architecture for the random systems is proposed in this paper. The conventional internal model principle as an effective control method depending on the structural knowledge of the external stimuli is applied to cancel the external inputs to achieve the trajectory tracking. However, it is known that there always exist uncertain random disturbances in systems, especially in a physical model working. For this situation, this paper constructs a new controller with the internal model form, such that the closed-loop system to be noise-to-state stable in the mean square (NSS-2-M). As a natural extension, considering the uncertainties of the exosystem, an adaptive internal control law is proposed in this paper and the noise-to-state practically stable in the mean square (NSpS-2-M) of the closed-loop system is also presented. The simulation results illustrate that all the signals of the closed-loop system are bounded, and the tracking error tends to an arbitrarily small neighborhood of the origin by turning the designed parameters. © 2022 Li, C., Zhang, X. On identifiability of discrete-time nonlinearly parameterized systems (2022) 160, art. no. 105128, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123617284&doi=10.1016%2fj.sysconle.2021.105128&partnerID=40&md5=2cb667fe992bded6a7ed128e9f543fad DOI: 10.1016/j.sysconle.2021.105128 AFFILIATIONS: Key Laboratory of Systems and Control, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing, 100190, China; School of Mathematical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China ABSTRACT: This note shows that the identifiability of a nondivergent parameterized system depends on the density of the so called excitation points, which is a property of the underlying system. To ensure the identifiability, a lower bound of the density is computed, described by the random external signal (or process noise) bound. © 2022 Elsevier B.V. Krener, A.J. Corrigendum to “Boundary Control of the Beam Equation by Linear Quadratic Regulation” (Systems & Control Letters (2021) 153, (S0167691121000797), (10.1016/j.sysconle.2021.104949)) (2022) 160, art. no. 105118, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123603001&doi=10.1016%2fj.sysconle.2021.105118&partnerID=40&md5=9c14b1f5f772d66e9d28571f5b0caa63 DOI: 10.1016/j.sysconle.2021.105118 AFFILIATIONS: Naval Postgraduate School, 833 Dyer Road MontereyCA 93943-5216, United States ABSTRACT: We correct a mistake that we made in [1]. The mistake that we made was assuming the closed loop spatial modes were the same as the open loop spatial modes. The open loop spatial modes are real sinusoids while the closed loop spatial modes are actually complex sinusoids. If the beam equation is damped then all the open loop eigenvalues are in the open left half plane but if it is undamped all the open loop eigenvalues are on the imaginary axis. We also add a theorem that shows that under suitable hypothesis the LQR feedback moves all the eigenvalues of the undamped beam equation into the open left half plane. Corrections to Section 2.2, Decoupling the spatial frequencies We correct this subsection starting from equation (27) of the original paper. The closed loop eigenvalues [Formula presented] and eigenfunctions [Formula presented] of the closed loop system satisfy the same eigenpair equation as the open loop eigenpairs [Formula presented] but subject to new boundary conditions [Formula presented] The eigenpair equation is [Formula presented] which implies [Formula presented] So [Formula presented] is an eigenfunction of [Formula presented] with corresponding eigenvalue [Formula presented]. The eigenfunctions of [Formula presented] consist of four families, [Formula presented] where [Formula presented] could be complex. The corresponding eigenvalues are [Formula presented] Because of boundary conditions (2) and (4) we expect the closed loop eigenfunctions to be of the form [Formula presented] where the closed loop eigenvalues [Formula presented] are given by [Formula presented]. In the undamped case, [Formula presented] , this reduces to [Formula presented]. The boundary conditions (3) and (5) require that [Formula presented] If [Formula presented] is not an integer multiple of [Formula presented] then [Formula presented] Notice that [Formula presented] and [Formula presented] differ by an integer multiple of [Formula presented] so [Formula presented] and hence [Formula presented] Furthermore [Formula presented] Suppose [Formula presented] then (3) and (5) are four real equations in four real unknowns [Formula presented]. We truncated the infinite sum in (8) to its first [Formula presented] terms and numerically solved for the real and imaginary parts first four closed loop spatial modes. They are shown in Figs. 1 and 2. The open loop spatial modes are in blue, the real part of the closed loop spatial modes are in red and the imaginary part of the closed loop spatial modes are in green. It appears that the closed loop modes rapidly converge to the open loop modes. Here are the first four [Formula presented] ’s [Formula presented] the first four [Formula presented] ’s [Formula presented] and the first four closed loop eigenvalues [Formula presented] ’s [Formula presented] Notice that all four closed loop eigenvalues are in the left half plane but they appear to be approaching the imaginary axis as the wave number increases. Corrections to Section 2.3, Convergence The last paragraph of this subsection is incorrect because it assumed the open loop and closed spatial modes were the same. Here is an alternative argument that shows under suitable assumptions that the LQR feedback shifts all the eigenvalues into open left half plane in the undamped case, [Formula presented]. In the original paper we showed that the series expansions of all the four components of [Formula presented] converge uniformly to continuous functions if [Formula presented] goes to zero like [Formula presented] with [Formula presented]. If we assume that [Formula presented] and if [Formula presented] is a closed loop eigenfunction of the form (6) then [Formula presented] where [Formula presented] indicates conjugate transpose. This quantity is positive because if the analytic function [Formula presented] is orthogonal to [Formula presented] for all [Formula presented] then its Fourier series consists of terms involving only [Formula presented]. But [Formula presented] is an odd function and [Formula presented] are even functions. Hence [Formula presented] is not zero it cannot be orthogonal to all [Formula presented] and so at least one term in the sum is positive. The other terms are at least nonnegative so we know the sum is positive. If the initial condition is an eigenfunction, [Formula presented] , then the closed loop trajectory is [Formula presented] where [Formula presented] is the corresponding closed loop eigenvalues. We know from the completing the square process that [Formula presented] Since [Formula presented] goes to zero like [Formula presented] with [Formula presented] we know that [Formula presented] is continuous and we also know that [Formula presented] is continuous it follows that the right side is bounded hence the left side must be bounded. This is possible iif all the closed loop eigenvalues are in the open left half plane. So the closed loop system is asymptotically stable. We are not claiming it is exponentially stable because the closed loop eigenvalues appear to approach the imaginary axis as the wave number goes to infinity. Revision to Section 3, Conclusions The conclusion of the original paper was as follows. “We have used the simple and constructive technique of completing the square to solve the LQR problem for the stabilization of the linear beam equation using boundary control. The result is an explicit formula for the quadratic optimal cost and the linear optimal feedback. Our approach allows us to decouple the spatial frequencies so we can damp out all or just some frequencies. ” To this we add that the closed loop eigenvalues can have a nonzero imaginary part and the corresponding closed loop eigenfunctions can involve complex sinusoids. We have also shown that under suitable hypothesis all the closed loop eigenvalues are in the open left half plane so the closed loop system is asymptotically stable. We apologize to the readers that we did not catch our mistake in the original version of this paper and we thank the editor for giving us the opportunity to correct our mistake. © 2021 Aryal, S., Nemani, S. Stability of polynomials under uniform perturbation (2022) 160, art. no. 105132, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123314764&doi=10.1016%2fj.sysconle.2022.105132&partnerID=40&md5=7c04645803b5b265a6457de3191bbbb9 DOI: 10.1016/j.sysconle.2022.105132 AFFILIATIONS: Department of Mathematics, Computer Science, & Physics, Georgian Court University, Lakewood, NJ, United States ABSTRACT: In this work, we consider variations of the conjecture presented by Fernández-Anaya and Martínez-García (2004) on robustness of stable transfer functions and associated polynomials. We establish some classes of stable polynomials and perturbing functions such that the perturbations of the polynomials remain stable. © 2022 Elsevier B.V. Lee, J.G., Kim, J. Mixed analog–digital method of designing a heterogeneous network with the desired collective behavior and rapid convergence (2022) 160, art. no. 105126, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123202661&doi=10.1016%2fj.sysconle.2021.105126&partnerID=40&md5=d286f498f79c335f7ec259d86a3e93b8 DOI: 10.1016/j.sysconle.2021.105126 AFFILIATIONS: Control Group, Department of Engineering, University of Cambridge, United Kingdom; Division of Decision and Control System at KTH Royal Institute of Technology, Sweden ABSTRACT: Among many advances given by the diffusive coupling on the synchronization problem, recently a design method for a continuous-time heterogeneous network with the desired collective behavior has been developed. Meanwhile, by its use of high-gain, implementation issues arise in discrete-time frameworks. The goal of this paper is thus to introduce a simple scheme that follows the philosophy of Carver Mead, a pioneer of VLSI (Very Large Scale Integration) technology, that removes those implementation issues. In the end, we utilize what corresponds to derivative consensus in continuous-time, which can be realized by, for instance, an analog electric circuit. This provides a mixed analog–digital method of designing a heterogeneous network with the desired collective behavior and rapid convergence. © 2022 The Author(s) Sarafrazi, M.A. Comments on “On structural accessibility of network nonlinear systems” (2022) 160, art. no. 105124, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122629105&doi=10.1016%2fj.sysconle.2021.105124&partnerID=40&md5=6e09a478232a2dc21a0b895de597e02b DOI: 10.1016/j.sysconle.2021.105124 AFFILIATIONS: Rezvan complex, Motahari Sq., Motahari Blvd., Shiraz, 71868-98544, Iran ABSTRACT: In a recent paper (Meng et al., 2021), it was claimed that for meromorphic nonlinear systems linear in control input, generic controllability of the linearized system is necessary and sufficient for generic accessibility of the original system, and this result was used to prove equivalence between structural accessibility and structural controllability of the linearized system. We point out a mistake in the proof of the results of Meng et al. (2021) and show that controllability of the linearized system is only sufficient for accessibility of the original nonlinear system. The main result of the paper (Meng et al., 2021) about the relation between structural accessibility of the system and structural controllability of its linearized system can partially be remedied. © 2021 Tian, L., Ji, Z., Liu, Y., Lin, C. A unified approach for the influences of negative weights on system consensus (2022) 160, art. no. 105109, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121969475&doi=10.1016%2fj.sysconle.2021.105109&partnerID=40&md5=5055b360eaa3d7d39c30e06094c5474a DOI: 10.1016/j.sysconle.2021.105109 AFFILIATIONS: Shandong Key Laboratory of Industrial Control Technology, Institute of Complexity Science, College of Automation, School of Mathematics and Statistics, Qingdao University, Qingdao, Shandong 266071, China; Shandong Key Laboratory of Industrial Control Technology, Institute of Complexity Science, College of Automation, Qingdao University, Qingdao, Shandong 266071, China; School of Control Science and Engineering, Shandong University, Jinan, 250061, China ABSTRACT: In this paper, the influences of negative weights on the consensus problems of multi-agent systems are investigated. While the system is subject to external attacks or agents in the system break down, there are errors in information transmission between agents. As a result, for non-negative systems, the connection weights between agents may change, or even change from positive to negative. In this paper, we provide a unified approach to deal with the problem of how to ensure the consensus of the system when the connection weight becomes negative. It is found that the consensus of multi-agent systems and general linear multi-agent systems will be guaranteed while the weights change to a certain extent without changing the protocol and feedback gains. We obtain a necessary and sufficient condition to ensure that the system can still reach asymptotic consensus when the connection weight is negative. The result is applicable to first-order, high-order integrator type of multi-agent systems as well as the general linear multi-agent system. © 2021 Elsevier B.V. Wang, P., Gao, Y., Yu, N., Ren, W., Lian, J., Wu, D. Distributed and communication-efficient solutions to linear equations with special sparse structure (2022) 160, art. no. 105065, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121961504&doi=10.1016%2fj.sysconle.2021.105065&partnerID=40&md5=3bd59d07f0763ac96223a932b12dc1fa DOI: 10.1016/j.sysconle.2021.105065 AFFILIATIONS: Department of Automation, Shanghai Jiao Tong University, Shanghai, 200240, China; Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai, 200240, China; Shanghai Engineering Research Center of Intelligent Control and Management, Shanghai, 200240, China; University of California, Riverside, 900 University Ave, Riverside, CA 92521, United States; Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, United States; Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA 99354, United States ABSTRACT: In this paper, two distributed and communication-efficient algorithms based on the multi-agent system are proposed to solve a system of linear equations with the Laplacian sparse system matrix. One algorithm is based on the gradient descent method in optimization. In this algorithm, the agents only share partial information instead of all of their collective state vectors to save significant communication. The other algorithm is obtained by approximating Newton's method for a faster convergence rate. Although it requires twice as much communication as the first one, it is still communication-efficient given the low dimension of the information shared among agents. The convergence at a linear rate is proved for both algorithms, and a comprehensive comparison of their convergence rate, communication burden, and computation costs is also performed. The proposed algorithms can be applied to various systems to solve those problems that can be modeled as a system of linear equations with a Laplacian sparse system matrix. Simulation results with the electric power system illustrate their effectiveness. © 2021 Zhang, M., Liu, X., Su, H. Robust immersion and invariance adaptive fault-tolerant control of nonlinear systems with non-linearly parameterized faults (2022) 159, art. no. 105099, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121689430&doi=10.1016%2fj.sysconle.2021.105099&partnerID=40&md5=ab74a268ab090e74f0e56e4cdb25254d DOI: 10.1016/j.sysconle.2021.105099 AFFILIATIONS: School of Electronic Information Engineering, Beijing Jiaotong University, Beijing, China; Institute of Cyber-System and Control, Zhejiang University, Hangzhou, China ABSTRACT: This paper presents a robust adaptive fault-tolerant control (FTC) scheme based on Immersion and Invariance (I&I) manifold method for a class of disturbed nonlinear systems on the occurrence of non-linearly parameterized (NLP) faults. The fault detection method based on adaptive observer is proposed firstly, and the fault tolerant controller for the NLP faults based on robustified I&I adaptation law is presented on the basis of nominal control law. Different from traditional adaptation law, the proposed robustified I&I adaptation law can not only eliminate the parameterized uncertainty but also shape the convergnce performance of the parameter estimates. The stability of the closed-loop system is rigorously analyzed. Numerical simulations are carried out to verify the effectiveness of the proposed scheme. © 2021 Elsevier B.V. Borkar, V.S. Corrigendum to “A concentration bound for contractive stochastic approximation” [Syst. Control Lett. 153 (2021) 104947] (Systems & Control Letters (2021) 153, (S0167691121000773), (10.1016/j.sysconle.2021.104947)) (2022) 159, art. no. 105086, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85120457265&doi=10.1016%2fj.sysconle.2021.105086&partnerID=40&md5=b95d4cc908e3bd95747faf5888d2f085 DOI: 10.1016/j.sysconle.2021.105086 AFFILIATIONS: Department of Electrical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India ABSTRACT: We correct an error in the statement of the main result of Borkar (2021) and also point out some improvements. © 2021 Elsevier B.V. Xing, Z. Mean-field backward stochastic differential equations with reflection and related nonlocal PDEs in a convex domain (2022) 159, art. no. 105081, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119922792&doi=10.1016%2fj.sysconle.2021.105081&partnerID=40&md5=b6aa070eb2b87f96ca9546a48ef342c1 DOI: 10.1016/j.sysconle.2021.105081 AFFILIATIONS: School of Control Science and Engineering, Shandong University, Jinan, 250061, China ABSTRACT: In this paper, we present the unique solvability of a type of reflected mean-field backward stochastic differential equation (RMFBSDE) in a convex domain. Moreover, employing the techniques of stochastic flow and penalization, we present a probabilistic interpretation in the Sobolev sense for a kind of reflected nonlocal partial differential equation (PDE) in a convex domain. The results of this paper provide the foundation of studying control problems of constrained mean-field systems. © 2021 Boarotto, F., Caravenna, L., Rossi, F., Vittone, D. On the Lebesgue measure of the boundary of the evoluted set (2021) 158, art. no. 105078, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85119247487&doi=10.1016%2fj.sysconle.2021.105078&partnerID=40&md5=c7a8ee5b1aa8f2901d8d4ca8bab0694d DOI: 10.1016/j.sysconle.2021.105078 AFFILIATIONS: Dipartimento di Matematica “Tullio Levi-Civita”, Università degli Studi di Padova, Via Trieste 63, Padova, 35121, Italy ABSTRACT: The evoluted set is the set of configurations reached from an initial set via a fixed flow for all times in a fixed interval. We find conditions on the initial set and on the flow ensuring that the evoluted set has negligible boundary (i.e. its Lebesgue measure is zero). We also provide several counterexample showing that the hypotheses of our theorem are close to sharp. © 2021 Elsevier B.V. Srighakollapu, M.V., Kalaimani, R.K., Pasumarthy, R. Optimizing network topology for average controllability (2021) 158, art. no. 105061, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118938441&doi=10.1016%2fj.sysconle.2021.105061&partnerID=40&md5=34cc2a7105fb35ed713b66ee54a8791c DOI: 10.1016/j.sysconle.2021.105061 AFFILIATIONS: Department of Electrical Engineering, Indian Institute of Technology Madras, Chennai, 600036, India ABSTRACT: We address the problem of identifying a network topology of a networked system for maximizing a controllability measure, the average controllability under constraints on the number of links in the network. We consider networked systems consisting of subsystems with higher-order discrete-time linear time-invariant dynamics. We show that the average controllability is a monotone increasing supermodular function of a set of links in the networked system. Since maximizing such a function with cardinality constraints is an NP-hard problem, we analyze the performance guarantees obtained from the greedy algorithm for maximizing non-submodular set functions in terms of supermodular curvature. We show that the lower bound obtained for the greedy algorithm becomes trivial as the number of subsystems in the networked system increases. Hence, we propose two heuristic algorithms to solve the optimization problem and numerically demonstrate the efficiency of the proposed heuristics in terms of computational complexity and performance improvement in average controllability. © 2021 Elsevier B.V. Bárcena-Petisco, J.A., Zuazua, E. Averaged dynamics and control for heat equations with random diffusion (2021) 158, art. no. 105055, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118349243&doi=10.1016%2fj.sysconle.2021.105055&partnerID=40&md5=a7191ceb6466b7b5f2637ff1296494d2 DOI: 10.1016/j.sysconle.2021.105055 AFFILIATIONS: Departamento de Matemáticas, Universidad Autónoma de Madrid, Madrid, 28049, Spain; Chair of Computational Mathematics, Fundación Deusto, Avenida de las Universidades 24, Bilbao, Basque Country, 48007, Spain; Chair of Dynamics, Control and Numerics, Alexander von Humboldt-Professorship, Department of Data Science, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, 91058, Germany ABSTRACT: This paper deals with the averaged dynamics for heat equations in the degenerate case where the diffusivity coefficient, assumed to be constant, is allowed to take the null value. First we prove that the averaged dynamics is analytic. This allows to show that, most often, the averaged dynamics enjoys the property of unique continuation and is approximately controllable. We then determine if the averaged dynamics is actually null controllable or not depending on how the density of averaging behaves when the diffusivity vanishes. In the critical density threshold the dynamics of the average is similar to the [Formula presented]-fractional Laplacian, which is well-known to be critical in the context of the controllability of fractional diffusion processes. Null controllability then fails (resp. holds) when the density weights more (resp. less) in the null diffusivity regime than in this critical regime. © 2021 The Author(s) Zhang, S., Xiong, J., Shi, J. A linear–quadratic optimal control problem of stochastic differential equations with delay and partial information (2021) 157, art. no. 105046, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117904310&doi=10.1016%2fj.sysconle.2021.105046&partnerID=40&md5=08045e7f1625269b02528837c838b364 DOI: 10.1016/j.sysconle.2021.105046 AFFILIATIONS: School of Mathematics, China University of Mining and Technology, Xuzhou, 221116, China; Department of Mathematics, Southern University of Science and Technology, Shenzhen, 518055, China; School of Mathematics, Shandong University, Jinan, 250100, China ABSTRACT: This paper deals with a linear quadratic partially observed optimal control problem for the state governed by stochastic differential equations with delay. By backward separation method, variational method and filtering technique, a stochastic maximum principle for the optimal control is developed and its feedback representation is obtained. Also, a sufficient condition without the assumption of concavity is presented. At last, two examples are solved explicitly. © 2021 Elsevier B.V. Fu, L. Exponential stability of abstract Coleman–Gurtin equations in Hilbert spaces (2021) 157, art. no. 105053, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117572892&doi=10.1016%2fj.sysconle.2021.105053&partnerID=40&md5=2658372dffb803b679cd54c7ba865813 DOI: 10.1016/j.sysconle.2021.105053 AFFILIATIONS: School of Mathematical and Computational Science, Hunan University of Science and Technology, Xiangtan, Hunan, 411201, China ABSTRACT: We study a class of integro-differential equations in Hilbert spaces which fits the Coleman–Gurtin model of heat conduction with memory. Well-posedness of the equation is established and sufficient conditions for exponential stability of the equation are given. This is done by using the semigroup approach. An illustrative example is given and the obtained theoretical results are verified by numerical simulations. © 2021 Elsevier B.V. Mo, Y., Yu, L. A Lyapunov analysis of the continuous-time adaptive Bellman–Ford algorithm (2021) 157, art. no. 105045, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117572434&doi=10.1016%2fj.sysconle.2021.105045&partnerID=40&md5=ca960140a370e4841a8cf0b60f0f1a0a DOI: 10.1016/j.sysconle.2021.105045 AFFILIATIONS: Institute of Advanced Technology, Westlake Institute for Advanced Study, Westlake University, Hangzhou, 310024, China ABSTRACT: The shortest path problem, one of the most classical graph problems, has been addressed in many different ways suitable for various settings in the fields of computer science and artificial intelligence. In this paper, we revisit a distributed control solution, namely the continuous-time adaptive Bellman–Ford algorithm, to the shortest path problem. While previous work only concerned its global asymptotic stability, we not only prove its global asymptotic stability by formulating a Lyapunov function, but characterize the initial conditions under which the algorithm will converge exponentially, and show that the algorithm is globally ultimately bounded under persistent bounded perturbations based on the proposed Lyapunov function. © 2021 Elsevier B.V. Saldi, N. Large deviations principle for discrete-time mean-field games (2021) 157, art. no. 105042, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85116598619&doi=10.1016%2fj.sysconle.2021.105042&partnerID=40&md5=2590e93a76ac520ca6a6c1b2c7928d36 DOI: 10.1016/j.sysconle.2021.105042 AFFILIATIONS: Özyeğin University, Çekmeköy, İstanbul, Turkey ABSTRACT: In this paper, we establish a large deviations principle (LDP) for interacting particle systems that arise from state and action dynamics of discrete-time mean-field games under the equilibrium policy of the infinite-population limit. The LDP is proved under weak Feller continuity of state and action dynamics. The proof is based on transferring LDP for empirical measures of initial states and noise variables under setwise topology to the original game model via contraction principle, which was first suggested by Delarue, Lacker, and Ramanan to establish LDP for continuous-time mean-field games under common noise. We also compare our work with LDP results established in prior literature for interacting particle systems, which are in a sense uncontrolled versions of mean-field games. © 2021 Elsevier B.V. Colonius, F., Hasan, A., Lamouki, G.R.R. Controllability near a homoclinic bifurcation (2021) 156, art. no. 105026, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114223975&doi=10.1016%2fj.sysconle.2021.105026&partnerID=40&md5=20bfe651d4a724be0d730ecba4553664 DOI: 10.1016/j.sysconle.2021.105026 AFFILIATIONS: Institute of Mathematics, University of Augsburg, Augsburg, Germany; School of Mathematics, Statistics, and Computer Science, College of Science, University of Tehran, Iran; Faculty of Mechanical and Electrical Engineering, Damascus University, Syrian Arab Republic ABSTRACT: Controllability properties are studied for control-affine systems depending on a parameter α and with constrained control values. The uncontrolled systems in dimension two and three are subject to a homoclinic bifurcation. This generates two families of control sets depending on a parameter in the involved vector fields and the size of the control range. A new parameter β given by a split function for the homoclinic bifurcation determines the behavior of these control sets. It is also shown that there are parameter regions where the uncontrolled equation has no periodic orbits, while the controlled systems have periodic solutions arbitrarily close to the homoclinic orbit. © 2021 Elsevier B.V. Goreac, D., Munteanu, I. Improved stability for linear SPDEs using mixed boundary/internal controls (2021) 156, art. no. 105024, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113545623&doi=10.1016%2fj.sysconle.2021.105024&partnerID=40&md5=036504104efa8cd96d8fe4c090ea0688 DOI: 10.1016/j.sysconle.2021.105024 AFFILIATIONS: School of Mathematics and Statistics, Shandong University, WeihaiWeihai 264209, China; LAMA, Univ Gustave Eiffel, UPEM, Univ Paris Est Creteil, CNRS, Marne-la-Valleée, F-77447, France; Faculty of Mathematics, Al. I. Cuza University, Bd. Carol I, Iasi, 11700506, Romania; O. Mayer Institute of Mathematics, Romanian Academy, Bd. Carol I, Iasi, 8700505, Romania ABSTRACT: This paper is motivated by the asymptotic stabilization of abstract SPDEs of linear type. As a first step, it proposes an abstract contribution to the exact controllability (in a general Lp-sense, p>1) of a class of linear SDEs with general time-invariant rank control coefficient in the diffusion term. From this point of view, our paper generalizes some of the results in Wang et al. (2017) where full and null rank were considered. Necessary conditions and sufficient ones are discussed and their hierarchy and connections with the approximate controllability are illustrated. Second, our paper illustrates, on relevant frameworks of linear SPDEs, a way to drive exactly to 0 their unstable part of dimension n≥1 by using M internal, respectively N boundary controls such that maxM,N<n. Extensive examples are presented as is the minimal gain for judicious control pairs. © 2021 Elsevier B.V. Vuillemin, P., Maillard, A., Poussot-Vassal, C. Optimal modal truncation (2021) 156, art. no. 105011, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112331393&doi=10.1016%2fj.sysconle.2021.105011&partnerID=40&md5=e911ebe585ddd78787a70a677d210518 DOI: 10.1016/j.sysconle.2021.105011 AFFILIATIONS: ONERA/DTIS, Université de Toulouse, Toulouse, F-31055, France; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, United States ABSTRACT: This paper revisits modal truncation from an optimisation point of view. In particular, the concept of dominant poles is formulated with respect to different system norms as the solution of the associated optimal modal truncation problem. The latter is reformulated as an equivalent convex integer or mixed-integer program. Numerical examples highlight the concept and optimisation approach. © 2021 Elsevier B.V. Wetzlinger, M., Reichhartinger, M., Horn, M. Higher order sliding mode inspired nonlinear discrete-time observer (2021) 155, art. no. 104992, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111284874&doi=10.1016%2fj.sysconle.2021.104992&partnerID=40&md5=ec55d10479c9897bbb99598012b233f8 DOI: 10.1016/j.sysconle.2021.104992 AFFILIATIONS: Institute of Automation and Control, Faculty of Electrical and Information Engineering, Graz University of Technology, Graz, Austria; Christian Doppler Laboratory for Model Based Control of Complex Test Bed Systems, Institute of Automation and Control, Graz University of Technology, Graz, Austria ABSTRACT: This work proposes a design scheme for arbitrary order discrete-time sliding mode observers for input-affine nonlinear systems. The dynamics of the estimation errors are represented in a pseudo-linear form, where the coefficients of the characteristic polynomial comprise the nonlinearities of the algorithm. The design process is reduced to a state-dependent eigenvalue placement procedure. Moreover, two different discrete-time eigenvalue mappings are proposed. As basis for the eigenvalue mappings serves a modified version of the continuous-time uniform robust exact differentiator. Due on the chosen eigenvalue mapping the proposed algorithm does not suffer from discretization chattering. Global asymptotic stability of the estimation errors for observers of order 2 and 3 is proven and the method to prove stability for higher order observers is demonstrated. The performance of a 3-rd order observer is illustrated in simulation. Simulation studies indicate that proposed discrete-time observer might possess an upper bound of its convergence time independent of the initial conditions. © 2021 The Author(s) Belabbas, M.-A., Chen, X. On integer balancing of directed graphs (2021) 154, art. no. 104980, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85109573519&doi=10.1016%2fj.sysconle.2021.104980&partnerID=40&md5=e68a2a82fdc2f431764d7060fe58cc49 DOI: 10.1016/j.sysconle.2021.104980 AFFILIATIONS: Department of Electrical and Computer Engineering and Coordinated Science Laboratory, University of Illinois, Urbana-Champaign, IL, United States; Department of Electrical, Computer, and Energy Engineering, University of Colorado BoulderCO, United States ABSTRACT: A weighted digraph is balanced if the sums of the weights of the incoming and of the outgoing edges are equal at each vertex. We show that if these sums are integers, then for any edge weights satisfying the balance conditions, there exist integer weights obtained by rounding the original weights up or down that preserve both the balance condition and the sum of all edge weights. © 2021 Elsevier B.V. Polekhin, I. On the application of the Ważewski method to the problem of global stabilization (2021) 153, art. no. 104953, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105487058&doi=10.1016%2fj.sysconle.2021.104953&partnerID=40&md5=5e788ecdb575014da9fed4f0fa73b5ab DOI: 10.1016/j.sysconle.2021.104953 AFFILIATIONS: Steklov Mathematical Institute of the Russian Academy of Sciences, Moscow, Russian Federation ABSTRACT: We consider a possible application of the Ważewski topological method to feedback control systems and to more general dynamical systems. We show how this method can be used to prove the impossibility of global stabilization in such problems. Moreover, we give sufficient conditions for the existence of a solution such that its trajectory never leaves a subset of the extended phase space of the system and does not tend asymptotically to a given equilibrium. We illustrate our result with various real-life systems including the Furuta pendulum and the wheeled inverted pendulum. © 2021 Elsevier B.V. Li, Y., Tang, S. Approximation of BSDEs with super-linearly growing generators by Euler's polygonal line method: A simple proof of the existence (2021) 153, art. no. 104952, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105293701&doi=10.1016%2fj.sysconle.2021.104952&partnerID=40&md5=0ea4c4abc22cf57326ab1bab90b62a54 DOI: 10.1016/j.sysconle.2021.104952 AFFILIATIONS: Department of Finance and Control Sciences, School of Mathematical Sciences, Fudan University, Shanghai, 200433, China ABSTRACT: This paper develops the Euler's polygonal line method for the backward stochastic differential equations (BSDEs) with super-linearly growing generators. The generators are allowed to be super-linearly growing in the first unknown variable y and sub-quadratic growing in the second unknown variable z when the monotonicity condition is satisfied. The convergence rate of the Euler approximation is derived, which also provides a simple proof for the existence of the solution to the monotone BSDEs. The proof is very simple and short, without involving the conventional techniques of truncating and smoothing on the generators. © 2021 Elsevier B.V. Yong, J., Zhang, J. Non-equivalence of stochastic optimal control problems with open and closed loop controls (2021) 153, art. no. 104948, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105051368&doi=10.1016%2fj.sysconle.2021.104948&partnerID=40&md5=3370f9c98683dc0d5b71e94b2a868a01 DOI: 10.1016/j.sysconle.2021.104948 AFFILIATIONS: Department of Mathematics, University of Central Florida, Orlando, FL 32816, United States; Department of Mathematics, University of Southern California, Los Angeles, CA 90089, United States ABSTRACT: For an optimal control problem of an Itô’s type stochastic differential equation, the control process could be taken in open-loop or closed-loop forms. In the standard literature, provided appropriate regularity, the value functions under these two types of controls are equal and are the unique (viscosity) solution to the corresponding (path-dependent) HJB equation. In this short note, we provide a counterexample in the path dependent setting showing that these value functions can be different in general. © 2021 Elsevier B.V. Ajala, O., Domínguez-García, A.D., Liberzon, D. Robust leader–follower synchronization of electric power generators (2021) 152, art. no. 104937, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105696432&doi=10.1016%2fj.sysconle.2021.104937&partnerID=40&md5=108446e180e9e276f854a32ab631505c DOI: 10.1016/j.sysconle.2021.104937 AFFILIATIONS: Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States; Coordinated Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, United States ABSTRACT: We consider the problem of synchronizing two electric power generators, one of which (the leader) is serving a time-varying electrical load, so that they can ultimately be connected to form a single power system. Each generator is described by a second-order reduced state–space model. We assume that the generator not serving an external load initially (the follower) has access to measurements of the leader's phase angle, corrupted by some additive disturbances. By using these measurements, and leveraging results on reduced-order observers with ISS-type robustness, we propose a procedure that drives (i) the angular velocity of the follower close enough to that of the leader, and (ii) the phase angle of the follower close enough to that of the point at which both systems will be electrically connected. An explicit bound on the synchronization error in terms of the measurement disturbance and the variations in the electrical load served by the leader is computed. We illustrate the procedure via numerical simulations. © 2021 Elsevier B.V. Jia, J., Trentelman, H.L., Charalampidis, N., Camlibel, M.K. Strong structural controllability of colored structured systems (2021) 152, art. no. 104924, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104678557&doi=10.1016%2fj.sysconle.2021.104924&partnerID=40&md5=b31f7ce77f027a1d835f28a80088f1ef DOI: 10.1016/j.sysconle.2021.104924 AFFILIATIONS: School of IoT Engineering, Jiangnan University, Wuxi, 214000, China; Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, 9700, Netherlands ABSTRACT: This paper deals with strong structural controllability of linear structured systems in which the system matrices are given by zero/nonzero/arbitrary pattern matrices. Instead of assuming that the nonzero and arbitrary entries of the system matrices can take their values completely independently, this paper allows equality constraints on these entries, in the sense that a priori given entries in the system matrices are restricted to take arbitrary but identical values. To formalize this general class of structured systems, we introduce the concepts of colored pattern matrices and colored structured systems. The main contribution of this paper is that it generalizes both the classical results on strong structural controllability of structured systems as well as recent results on controllability of systems defined on colored graphs. In this paper we will establish both algebraic and graph-theoretic conditions for strong structural controllability of this more general class of structured systems. © 2021 Elsevier B.V. Ramos, G., Aguiar, A.P., Pequito, S. Structurally quotient fixed modes (2021) 151, art. no. 104914, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85104068461&doi=10.1016%2fj.sysconle.2021.104914&partnerID=40&md5=edf211bb9b2a8c34741323caf1f7f29d DOI: 10.1016/j.sysconle.2021.104914 AFFILIATIONS: Department of Electrical and Computer Engineering, Faculty of Engineering, University of Porto, Portugal; Center for Systems and Control, Delft University of Technology, Netherlands ABSTRACT: We provide a necessary and sufficient graph-theoretical characterization of quotient fixes modes occurring in parametric decentralized control systems. Specifically, we introduce the notion of structurally quotient fixed modes (SQFMs) that generically captures the quotient fixed modes and only depends on the system's structure. Additionally, we provide an efficient polynomial-time algorithm for the verification of this graph-theoretical condition. We show that this algorithm can be parallelized, and linear-time computational complexity approximation algorithms can be considered to attain a sub-optimal solution. Lastly, we discuss the implications of the actuation–sensing–communication capabilities and the systems’ interconnections on the existence of SQFM. © 2021 Elsevier B.V. Karmakar, P., Bhatnagar, S. On tight bounds for function approximation error in risk-sensitive reinforcement learning (2021) 150, art. no. 104899, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103100349&doi=10.1016%2fj.sysconle.2021.104899&partnerID=40&md5=39be97b7083234ed821e63a07d73a995 DOI: 10.1016/j.sysconle.2021.104899 AFFILIATIONS: Department of Computer Science and Automation, Indian Institute of Science Bangalore, India ABSTRACT: In this letter we provide several informative tight error bounds when using value function approximators for the risk-sensitive cost setting for a given policy represented using exponential utility. The novelty of our approach is that we make use of the irreducibility of the underlying Markov chain (resulting in better bounds using Perron–Frobenius eigenvectors) to derive new bounds whereas the earlier work used primarily the spectral variation bound which holds for any matrix, hence did not make use of the irreducibility. All our bounds have a perturbation term for large state spaces. We also present examples where we show that the new bounds perform 90-100% better than the earlier proposed spectral variation bound. © 2021 Elsevier B.V. Braidiz, Y., Polyakov, A., Efimov, D., Perruquetti, W. On finite/fixed-time stability analysis based on sup- and sub-homogeneous extensions (2021) 150, art. no. 104893, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85102064693&doi=10.1016%2fj.sysconle.2021.104893&partnerID=40&md5=39dbbab516f0347b43afbd7338a40832 DOI: 10.1016/j.sysconle.2021.104893 AFFILIATIONS: Univ. Lille, CNRS, Centrale Lille, UMR 9189 - CRIStAL, Lille, F-59000, France; Univ. Lille, CNRS, Inria, UMR 9189 - CRIStAL, Lille, F-59000, France; ITMO University, 49 av. Kronverkskiy, Saint Petersburg, 197101, Russian Federation ABSTRACT: Fixed-time and finite-time stabilities of non-linear systems are investigated using the introduced notions of sub- and sup-homogeneity. These concepts allow the systems to be analyzed using the homogeneity, even if they do not admit homogeneous approximations. Finite-time and fixed-time stability properties can be established using homogeneity degree of sub- and sup-homogeneous extensions. © 2021 Elsevier B.V. Ha, N.T. On the robust stability of Volterra differential–algebraic equations (2021) 149, art. no. 104883, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100883348&doi=10.1016%2fj.sysconle.2021.104883&partnerID=40&md5=96bcded92822bae4227f0909e6ef69f1 DOI: 10.1016/j.sysconle.2021.104883 AFFILIATIONS: Department of Science, Electric Power University, 235 Hoang Quoc Viet Str., Hanoi, Viet Nam ABSTRACT: This paper deals with the robust stability of Volterra differential–algebraic equations. We consider the solvability of the equation and then the preservation of exponential stability under small perturbations. The so-called Bohl–Perron type theorem is also studied. © 2021 Elsevier B.V. Fehér, Á., Márton, L. Approximation and control of a class of distributed delay systems (2021) 149, art. no. 104882, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85100625189&doi=10.1016%2fj.sysconle.2021.104882&partnerID=40&md5=2006b3ffe6b567efa69aa5327227e282 DOI: 10.1016/j.sysconle.2021.104882 AFFILIATIONS: Department of Electrical Engineering, Sapientia Hungarian University of Transylvania, Corunca, Mures, 547367, Romania; Department of Mathematics, University of Pannonia, Veszprém, 8200, Hungary ABSTRACT: In this paper, we show that a linear system with distributed state delay can be approximated by a linear delay-free system that has the same state dimension as the original system if a so-called smallness condition holds. The smallness condition is an inequality which the maximum lag and norms of the system matrices have to satisfy. The eigenvalues of the approximate system correspond to the dominant eigenvalues of the original system with distributed delay. We provide a numerically stable, iterative algorithm to compute the state matrix of the approximate system. Furthermore, we show that, based on the proposed approximation, the stabilisation, pole placement and setpoint tracking control problems of the addressed class of distributed delay systems can be performed using methods developed for delay-free systems. Simulation results are provided to show the applicability of the proposed approximation and control design method. © 2021 Elsevier B.V. Wijnbergen, P., Trenn, S. Impulse-free interval-stabilization of switched differential algebraic equations (2021) 149, art. no. 104870, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099708913&doi=10.1016%2fj.sysconle.2020.104870&partnerID=40&md5=386d8e49f24a7bef2b3423d8a772c33f DOI: 10.1016/j.sysconle.2020.104870 AFFILIATIONS: Bernoulli Institute for Mathematics, Computer Science and Artificial Intelligence, University of Groningen, Groningen, Netherlands ABSTRACT: In this paper stabilization of switched differential algebraic equations is considered, where Dirac impulses in both the input and the state trajectory are to be avoided during the stabilization process. First it is shown that stabilizability of a switched DAE and the existence of impulse-free solutions are merely necessary conditions for impulse-free stabilizability. Then necessary and sufficient conditions for the existence of impulse-free solutions are given, which motivate the definition of (impulse-free) interval-stabilization on a finite interval. Under a uniformity assumption, which can be verified for a broad class of switched systems, stabilizability on an infinite interval can be concluded based on interval-stabilizability. As a result a characterization of impulse-free interval stabilizability is given and as a corollary we provide a novel impulse-free null-controllability characterization. Finally, the results are compared to results on interval-stabilizability where Dirac impulses are allowed in the input and state trajectory. © 2021 The Author(s) Avdonin, S., Avdonina, N., Edward, J., Nurtazina, K. Control and inverse problems for the heat equation with strong singularities (2021) 148, art. no. 104852, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098222279&doi=10.1016%2fj.sysconle.2020.104852&partnerID=40&md5=f79c0ddb86088b293416d23d54d08606 DOI: 10.1016/j.sysconle.2020.104852 AFFILIATIONS: Department of Mathematics and Statistics, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Moscow Center for Fundamental and Applied Mathematics, Moscow, 119991, Russian Federation; Department of Mathematics and Statistics, Florida International University, Miami, FL 33199, United States; L.N.Gumilyov Eurasian National University, 2 Satpayev Str., Nur Sultan, 010008, Kazakhstan ABSTRACT: We consider a linear system composed of N+1 one dimensional heat equations connected by point-mass-like interface conditions. Assume an L2 Dirichlet boundary control at one end, and Dirichlet boundary condition on the other end. Given any L2-type initial temperature distribution, we show that the system is null controllable in arbitrarily small time. The proof uses known results for exact controllability for the associated wave equation. An argument using the Fourier Method reduces the control problem for both the heat equation and the wave equation to certain moment problems. Controllability is then proved by relating minimality properties of the family of exponential functions associated to the wave with the family associated to the heat equation. Based on the controllability result we solve the dynamical inverse problem, i.e. recover unknown parameters of the system from the Dirichlet-to-Neumann map given at a boundary point. © 2020 Elsevier B.V. Calzavara, G., Consolini, L., Kavaja, J. Structured identification for network reconstruction of RC-models (2021) 147, art. no. 104849, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85098465974&doi=10.1016%2fj.sysconle.2020.104849&partnerID=40&md5=16b2d9551bb1bfa97ffe4eb840877ac1 DOI: 10.1016/j.sysconle.2020.104849 AFFILIATIONS: Dipartimento di Ingegneria e Architettura, Università degli Studi di Parma, Parco Area delle Scienze, 181/A, Parma, 43124, Italy ABSTRACT: Resistive–capacitive (RC) networks are used to model various processes in engineering, physics or biology. We consider the problem of recovering the network connection structure from measured input–output data. We address this problem as a structured identification one, that is, we assume to have a state-space model of the system (identified with standard techniques, such as subspace methods) and find a coordinate transformation that puts the identified system in a form that reveals the nodes connection structure. We characterize the solution set, that is, the set of all possible RC-networks that can be associated to the input–output data. We present a possible solution algorithm and show some computational experiments. © 2020 Elsevier B.V. Li, L., Zhang, H., Wang, Y. Stabilization and optimal control of discrete-time systems with multiplicative noise and multiple input delays (2021) 147, art. no. 104833, . https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097338370&doi=10.1016%2fj.sysconle.2020.104833&partnerID=40&md5=de41414365753c19fc0dcec0f3182209 DOI: 10.1016/j.sysconle.2020.104833 AFFILIATIONS: College of Mechanical and Electronic Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China; School of Information Science and Engineering, Shandong Agricultural University, Taian, Shandong, 271018, China; College of Electrical Engineering and Automation, Shandong University of Science and technology, Qingdao, 266590, China; School of Mathematics and Statistics, Central South University, Changsha, Hunan, 410083, China ABSTRACT: This paper is concerned with the stabilization and optimal control of discrete-time systems with multiplicative noise and multiple input delays. First, it is shown that the systems are stabilizable if and only if some algebraic Riccati-type equations have a solution which satisfies a given condition. To the best of our knowledge, this is the first time to propose a necessary and sufficient stabilizing condition for general multiple-input delay systems with multiplicative noise. The method constructs a Lyapunov–Krasovskii function based on the optimal cost of a finite-horizon LQR problem. Next, under the assumption that the system is stabilizable, an infinite-horizon LQR problem is investigated. The optimal control and the optimal cost are given by the above algebraic Riccati-type equations. Finally, based on the above stabilizing condition, an exact delay range for the stabilization of the system is derived in a special case. © 2020 Elsevier B.V.