{"title":"Adaptive output feedback containment control for parabolic PDE multi-agent systems","authors":"Li Tang, Feixia Liu","doi":"10.1016/j.sysconle.2024.105994","DOIUrl":"10.1016/j.sysconle.2024.105994","url":null,"abstract":"<div><div>This paper investigates the output feedback containment control problem of multi-agent systems (MASs) with multiple leaders described by partial differential equations (PDEs). In contrast to MASs modeled by ODEs, the PDEs system studied in this paper considers additional spatial variables, which leads to traditional ODEs control design methods inapplicable, then the design of observer based adaptive distributed protocols is more challenging. Considering that leaders may be task-driven, the control inputs of the leaders are non-zero and time-varying. Through the introduction of nonlinear terms in the containment controller to eliminate the influence of leader control inputs, the paper ultimately achieves bounded tracking errors and containment errors for agents under undirected graph topologies. Finally, the designed control scheme is validated through examples.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 105994"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Adaptive leaderless consensus of MIMO multi-agent systems with unknown dynamics and nonlinear dynamic uncertainties","authors":"Yanhua Yang, Jie Mei, Guangfu Ma","doi":"10.1016/j.sysconle.2024.105983","DOIUrl":"10.1016/j.sysconle.2024.105983","url":null,"abstract":"<div><div>In this paper, the bipartite consensus problem of a class of unknown uncertain multi-agent systems (MASs) under a signed graph is investigated via a filter-based model-free reinforcement learning (RL) based fully distributed control scheme. First, considering the completely unknown dynamics of the agents, a novel filter-based model-free RL algorithm is proposed to learn the stabilizable feedback gain matrix via the online input–output data. Then, fully distributed algorithm with adaptive control gains is designed such that all agents reach bipartite consensus in the presence of dynamic uncertainties. Finally, a numerical simulation is illustrated to demonstrate the correctness and effectiveness of the proposed control scheme.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 105983"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Formal safety verification of non-deterministic systems based on probabilistic reachability computation","authors":"Yuminghao Xiao, Tianbing Xia, Hongdong Wang","doi":"10.1016/j.sysconle.2024.106014","DOIUrl":"10.1016/j.sysconle.2024.106014","url":null,"abstract":"<div><div>In this paper, we develop a formal safety verification method based on analytic probabilistic reachability computation, which can estimate the probability of controlled non-deterministic systems entering unsafe states subject to disturbances. Specifically, we employ stochastic differential equations (SDEs) to describe the dynamics of the system and resort to a regularized indicator function to express the collision probability between the state trajectory of the system and unsafe states. We proceed to formulate this collision probability as the viscosity solution to a second-order variational-inequality and provide a rigorous proof for such a novel interpretation. Moreover, we discuss the ENO-Godunov scheme for solving the deduced variational-inequality, which obviates the need for Monte-Carlo simulations and the optimality condition along a complex boundary. The developed framework offers a structured approach to identify potential risks in safety critical systems and maintains a user-friendly implementation. Lastly, we demonstrate the above application in a safety verification problem related to maritime navigation.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 106014"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On computation of approximate solutions to large-scale backstepping kernel equations via continuum approximation","authors":"Jukka-Pekka Humaloja, Nikolaos Bekiaris-Liberis","doi":"10.1016/j.sysconle.2024.105982","DOIUrl":"10.1016/j.sysconle.2024.105982","url":null,"abstract":"<div><div>We provide two methods for computation of continuum backstepping kernels that arise in control of continua (ensembles) of linear hyperbolic PDEs and which can approximate backstepping kernels arising in control of a large-scale, PDE system counterpart (with computational complexity that does not grow with the number of state components of the large-scale system). In the first method, we provide explicit formulae for the solution to the continuum kernels PDEs, employing a (triple) power series representation of the continuum kernel and establishing its convergence properties. In this case, we also provide means for reducing computational complexity by properly truncating the power series (in the powers of the ensemble variable). In the second method, we identify a class of systems for which the solution to the continuum (and hence, also an approximate solution to the respective large-scale) kernel equations can be constructed in closed form. We also present numerical examples to illustrate computational efficiency/accuracy of the approaches, as well as to validate the stabilization properties of the approximate control kernels, constructed based on the continuum.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 105982"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Muhammad Zaki Almuzakki , Bayu Jayawardhana , Aneel Tanwani , Antonis I. Vakis
{"title":"Exponential stabilization of linear systems using nearest-action control with countable input set","authors":"Muhammad Zaki Almuzakki , Bayu Jayawardhana , Aneel Tanwani , Antonis I. Vakis","doi":"10.1016/j.sysconle.2024.105992","DOIUrl":"10.1016/j.sysconle.2024.105992","url":null,"abstract":"<div><div>This paper studies stabilization of linear time-invariant (LTI) systems when control actions can only be realized in <em>finitely</em> many directions where it is possible to actuate uniformly or logarithmically extended positive scaling factors in each direction. Furthermore, a nearest-action selection approach is used to map the continuous measurements to a realizable action where we show that the approach satisfies a <em>weak</em> sector condition for multiple-input multiple-output (MIMO) systems. Using the notion of input-to-state stability, under some assumptions imposed on the transfer function of the system, we show that the closed-loop system converges to the target ball exponentially fast. Moreover, when logarithmic extension for the scaling factors is realizable, the closed-loop system is able to achieve asymptotic stability instead of only practical stability. Finally, we present an example of the application that confirms our analysis.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 105992"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Detectability of linear stochastic impulsive systems with state-dependent noises","authors":"Shixian Luo , Xin Chen , Feiqi Deng , Yan Jiang","doi":"10.1016/j.sysconle.2024.105989","DOIUrl":"10.1016/j.sysconle.2024.105989","url":null,"abstract":"<div><div>This paper focuses on the characterization of moment detectability and almost sure detectability for linear stochastic impulsive systems. The concepts and characterizations of the <span><math><mrow><mn>2</mn><mi>p</mi></mrow></math></span>th moment detectability and almost sure detectability are first introduced. Two expanded systems, the state-expanded stochastic system and the moment equation, are established by utilizing the generalized <span><math><mi>H</mi></math></span>-representation technique. A series of geometric and algebraic conditions for the <span><math><mrow><mn>2</mn><mi>p</mi></mrow></math></span>th moment detectability of the linear stochastic impulsive systems are established by analyzing the 2nd moment detectability of the state-expanded system and the complete detectability of the moment equation. Subsequently, by introducing a strictly positive-definite quasi-periodic composite polynomial Lyapunov candidate, almost sure detectability criteria are framed in terms of linear matrix inequalities, showing that almost sure detectability is less conservative than moment detectability. Finally, two numerical examples with comparisons are provided to illustrate the proposed theoretical results.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 105989"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143183644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Impulsive and impulse-free PD solutions of singular LQ control","authors":"Jovan Stefanovski","doi":"10.1016/j.sysconle.2025.106024","DOIUrl":"10.1016/j.sysconle.2025.106024","url":null,"abstract":"<div><div>This paper addresses the singular linear–quadratic (LQ) control problem, considering cases with or without impulses in the state, and with or without stability. The optimal controller obtained includes a derivative of the state. The assumptions made are system stabilizability and the left-invertibility of the plant transfer matrix. Necessary and sufficient conditions for stability and the impulse-freeness of the optimal state are provided. These conditions are related to the absence of invariant zeros on the imaginary axis, and at infinity with orders greater than one, as well as to strong<span><math><msup><mrow></mrow><mrow><mo>∗</mo></mrow></msup></math></span> detectability. When these conditions are not met, the subspace ensuring that the optimal state is impulse-free, if the initial state belongs to that subspace, is determined. Additionally, a suboptimal yet practically realizable controller is presented, along with an explicit expression for the difference between the cost functional values corresponding to the suboptimal and optimal controllers. Illustrative examples are included.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 106024"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ge Guo , Xinxin Zhang , Renyongkang Zhang , Jian Kang
{"title":"Event-triggered predefined-time distributed optimization algorithm based on zero-gradient-sum","authors":"Ge Guo , Xinxin Zhang , Renyongkang Zhang , Jian Kang","doi":"10.1016/j.sysconle.2025.106019","DOIUrl":"10.1016/j.sysconle.2025.106019","url":null,"abstract":"<div><div>This paper presents an event-triggered distributed optimization (DO) algorithm for consensus constraints and strongly convex local cost functions. The algorithm is derived by means of the zero-gradient-sum mechanism and sliding mode control, which is free from any initial conditions or local minimization. In order to avoid continuous communication and measurement, our algorithm enables the interaction between agents solely at event-triggered instants, resulting in conserving communication resources. Importantly, the proposed method drives system to the optimal consensus state within a predefined time. Simulation results demonstrate the effectiveness of our approach.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 106019"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Finite-time safe control of probabilistic Boolean networks: An event-triggered approach","authors":"Shao Shao , Linying Xiang , Fei Chen","doi":"10.1016/j.sysconle.2024.106012","DOIUrl":"10.1016/j.sysconle.2024.106012","url":null,"abstract":"<div><div>This paper explores finite-time safe control in probabilistic Boolean control networks (PBCNs) through event-triggered control (ETC), presenting necessary and sufficient conditions as a set-based testing framework for problem solvability under ETC. Despite the unsolvability of the safe control problem in PBCNs with non-intermittent feedback controllers, ETC offers a potential solution. The paper contributes an algorithm to calculate the feasible triggering set and corresponding feedback gain matrices. An illustrative example is included to highlight the practical effectiveness of the proposed approach.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 106012"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Approximate linear programming for decentralized policy iteration in cooperative multi-agent Markov decision processes","authors":"Lakshmi Mandal , Chandrashekar Lakshminarayanan , Shalabh Bhatnagar","doi":"10.1016/j.sysconle.2024.106003","DOIUrl":"10.1016/j.sysconle.2024.106003","url":null,"abstract":"<div><div>In this work, we consider a ‘cooperative’ multi-agent Markov decision process (MDP) involving <span><math><mrow><mi>m</mi><mrow><mo>(</mo><mo>></mo><mn>1</mn><mo>)</mo></mrow></mrow></math></span> agents. At each decision epoch, all the <span><math><mi>m</mi></math></span> agents independently select actions in order to minimize a common long-term cost objective. In the policy iteration process of multi-agent setup, the number of actions grows exponentially with the number of agents, incurring huge computational costs. Thus, recent works consider decentralized policy improvement, where each agent improves its decisions unilaterally, assuming that the decisions of the other agents are fixed. However, exact value functions are considered in the literature, which is computationally expensive for a large number of agents with high dimensional state–action space. Thus, we propose approximate decentralized policy iteration algorithms, using approximate linear programming with function approximation to compute the approximate value function for decentralized policy improvement. Further, we consider (both) cooperative multi-agent finite and infinite horizon discounted MDPs and propose suitable algorithms in each case. Moreover, we provide theoretical guarantees for our algorithms and also demonstrate their advantages over existing state-of-the-art algorithms in the literature.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"196 ","pages":"Article 106003"},"PeriodicalIF":2.1,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143182988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}