Automatica最新文献

{"title":"Distributed constrained online convex optimization with adaptive quantization","authors":"","doi":"10.1016/j.automatica.2024.111828","DOIUrl":"10.1016/j.automatica.2024.111828","url":null,"abstract":"<div><p>In this paper, we study distributed constrained online convex optimization (OCO) problem in a system consisting of a parameter server and <span><math><mi>n</mi></math></span> clients. Each client is associated with a local constraint function and time-varying local loss functions, which are disclosed sequentially. The clients seek to minimize the accumulated total loss subject to the total constraint by choosing sequential decisions based on causal information of the loss functions. Existing distributed constrained OCO algorithms require clients to send their raw decisions to the server, leading to large communication overhead unaffordable in many applications. To reduce the communication cost, we devise an adaptive quantization method, where the center and the radius of the quantizer are adjusted in an adaptive manner as the OCO algorithm progresses. We first examine the scenario of full information feedback, where the complete information of the loss functions is revealed at each time. We propose a distributed online saddle point algorithm with adaptive quantization, which can reduce the communication overhead considerably. The performance of this algorithm is analyzed, and an <span><math><mrow><mi>O</mi><mrow><mo>(</mo><msqrt><mrow><mi>T</mi></mrow></msqrt><mo>)</mo></mrow></mrow></math></span> regret bound and an <span><math><mrow><mi>O</mi><mrow><mo>(</mo><msup><mrow><mi>T</mi></mrow><mrow><mfrac><mrow><mn>3</mn></mrow><mrow><mn>4</mn></mrow></mfrac></mrow></msup><mo>)</mo></mrow></mrow></math></span> constraint violation bound are established, which are the same as (in order sense) those for existing algorithm transmitting raw decisions without quantization. We further extend the adaptive quantization method to the scenario of bandit feedback, where only the values of the local loss functions at two points are revealed at each time. A bandit OCO algorithm with adaptive quantization is developed and is shown to possess the same (in order sense) regret and constraint violation bounds as in the full information feedback case. Finally, numerical results on distributed online rate control problem are presented to corroborate the efficacy of the proposed algorithms.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Distributed learning in congested environments with partial information","authors":"","doi":"10.1016/j.automatica.2024.111817","DOIUrl":"10.1016/j.automatica.2024.111817","url":null,"abstract":"<div><p>How can non-communicating agents learn to share congested resources efficiently? This is a challenging task when the agents can access the same resource simultaneously (in contrast to multi-agent multi-armed bandit problems) and the resource valuations differ among agents. We present a fully distributed algorithm for learning to share in congested environments and prove that the agents’ regret with respect to the optimal allocation is poly-logarithmic in the time horizon. Performance in the non-asymptotic regime is illustrated in numerical simulations. The distributed algorithm has applications in cloud computing and spectrum sharing.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Static anti-windup with shifted equilibria applied to a Segway-like vehicle","authors":"","doi":"10.1016/j.automatica.2024.111830","DOIUrl":"10.1016/j.automatica.2024.111830","url":null,"abstract":"<div><p>Leveraging recent results on bounded stabilization of linear plants using shifted equilibria, we propose a novel anti-windup scheme for linear input-saturated plants with (asymmetric) saturation limits. We show that, with open-loop plants involving a continuum of equilibria, the proposed anti-windup solution provides an unbounded estimate of the basin of attraction, thereby overcoming typical limits of classical solutions. We also report on experiments performed on a segway-like vehicle, where the controller effectively displaces the segway between any two locations, due to unboundedness of the basin of attraction.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0005109824003248/pdfft?md5=df2b56141c95aa2f9b4b085f7abef3a2&pid=1-s2.0-S0005109824003248-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal computing budget allocation for selecting the optimal subset of multi-objective simulation optimization problems","authors":"","doi":"10.1016/j.automatica.2024.111829","DOIUrl":"10.1016/j.automatica.2024.111829","url":null,"abstract":"<div><p>This study aims to develop an efficient budget allocation procedure for the problem of selecting an optimal subset of designs from a finite number of alternative designs in stochastic environments. The optimal subset might contain more alternative designs beyond the Pareto optimal ones. In this study, we adopt the Pareto rank to measure the performance of each design and define the optimal subset. Our objective is to minimize the probability that the optimal subset is falsely selected within a fixed limited simulation budget. We propose an upper bound of the probability of false selection and derive an asymptotically optimal simulation budget allocation rule based on the large deviation theory. We also provide some useful insights into how the simulation budget can be allocated to identify the optimal subset. The proposed budget allocation algorithm is compared with existing methods through numerical experiments, and the results show the efficiency of our proposed algorithm.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Leader–follower circumnavigation control of non-holonomic robots using distance-related information","authors":"","doi":"10.1016/j.automatica.2024.111831","DOIUrl":"10.1016/j.automatica.2024.111831","url":null,"abstract":"<div><p>This paper studies the leader–follower circumnavigation problem of two non-holonomic robots using just an angular velocity adjustment. Specifically, two robots orbit around a stationary target along a circle trajectory with a pre-specified spacing distance apart and velocity. However, two robots have no global positioning information and cannot localize the target. Instead, they can just obtain real-time distance-related information with respect to surrounding objects. Based on a leader–follower protocol framework, a distance-based control algorithm is developed to generate saturated control inputs for two robots. Besides, the criteria of the control parameters and initial states are explicitly established. It is demonstrated in detail that, under the established criteria, the developed distance-based control algorithm enables two robots to fulfill the leader–follower circumnavigation objective. Simulation and experiment are carried out to assess and demonstrate the effectiveness of the proposed theoretical results.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Leader–follower consensus using 2-rate distributed output feedback protocol without controller interaction","authors":"","doi":"10.1016/j.automatica.2024.111819","DOIUrl":"10.1016/j.automatica.2024.111819","url":null,"abstract":"<div><p>This paper deals with the leader–follower consensus control for a homogeneous, discrete-time, multi-agent system (MAS) with agents having non-minimum phase (NMP) zeros. Linear time-invariant (LTI) or single-rate distributed output feedback schemes in which, the controllers are not allowed to exchange their states with the neighbours, may fail to achieve this objective, if a certain speed of consensus is needed. To remedy this, a 2-rate scheme is proposed in this paper. The lifting technique is used to transform the design of the proposed 2-rate distributed controller into the design of an equivalent LTI or single-rate centralized controller for an equivalent LTI plant, satisfying some complex gain margin (GM) criteria. It is shown that the inherent zero-placement capability of the proposed controller can make this equivalent LTI plant minimum phase under certain conditions, which helps one attain a desired speed of the consensus response while satisfying the GM criteria. An <span><math><msub><mrow><mi>H</mi></mrow><mrow><mi>∞</mi></mrow></msub></math></span>/loop-transfer-recovery (LTR)-based approach is used to design the proposed controller. A suitable example is considered to show the efficacy of the proposed controller over its single-rate counterpart.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Saturated control of consensus value under energy and state constraints in multi-agent systems","authors":"","doi":"10.1016/j.automatica.2024.111822","DOIUrl":"10.1016/j.automatica.2024.111822","url":null,"abstract":"<div><p>This work presents a novel decentralized control strategy with a guaranteed cost for bilinear multi-agent systems subjected to products between the state and the control input, state constraints, and limitations on the amplitude and total energy of the control action, which can prevent the consensus from reaching the desired value. We propose state feedback and switching control laws to deal with these restrictions. The main objectives of the work are twofold: (i) to design control laws that ensure stability and guaranteed cost bounds under constraints, and (ii) to determine an estimation of the domain of attraction (DOA), as large as possible, characterized by a polyhedral and an ellipsoidal invariant region contained in the space defined by the state constraints. We adopt a convex optimization procedure based on linear matrix inequalities (LMI) to address these objectives. An original approach employing Lyapunov sets is proposed to deal with control energy and state constraints, and positive system properties are used to estimate the DOA in only one orthant of state space. Through numerical examples, we demonstrate the effectiveness of the proposed Lyapunov-based approach, showing its ability to handle complex constraints and large networks.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Density regulation of large-scale robotic swarm using robust model predictive mean-field control","authors":"","doi":"10.1016/j.automatica.2024.111832","DOIUrl":"10.1016/j.automatica.2024.111832","url":null,"abstract":"<div><p>This paper studies the density regulation problem for a large-scale robotic swarm with homogeneous agents. A novel robust model predictive mean-field control method is proposed to significantly improve the control performance and the algorithm scalability with the population size. To that end, a top-down control philosophy is first employed, under which the physical space is divided into finite disjoint bins and the actual density distribution (ADD) over these bins is taken as the macrostate. The system dynamics of ADD is then established by including a stochastic disturbance in the mean-field model, which describes the evolution process of each agent’s probability density distribution over the bins. Next, an optimization-based model predictive control method is developed to efficiently overcome the performance degradation raised by the disturbance term. Furthermore, the conditions ensuring the algorithm feasibility are strictly developed. We also prove that the actual swarm density converges to the target one in probability. Finally, simulation and comparison studies illustrate the effectiveness and advantages of the proposed algorithm over the existing results.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141953381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Resilient control of networked switched systems subject to deception attack and DoS attack","authors":"","doi":"10.1016/j.automatica.2024.111833","DOIUrl":"10.1016/j.automatica.2024.111833","url":null,"abstract":"<div><p>In this paper, the resilient control for switched systems in the presence of deception attack and denial-of-service (DoS) attack is addressed. Due to the interaction of two kinds of attacks and the asynchronous phenomenon of controller mode and subsystem mode, the system dynamics becomes much more complex. A criterion is derived to ensure the mean square security level of the closed-loop system. This in turn reveals the balance of system resilience and control performance. Furthermore, a mixed-switching control strategy is put forward to make the system globally asymptotically stable. It is shown that the system will still converge to the equilibrium even if the deception attack occurs. Finally, simulations are carried out to verify the effectiveness of the theoretical results.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141963562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"A segmented model based fuel delivery control of PEM fuel cells: A port-Hamiltonian approach","authors":"","doi":"10.1016/j.automatica.2024.111814","DOIUrl":"10.1016/j.automatica.2024.111814","url":null,"abstract":"<div><p>This paper proposes an extended interconnection and damping assignment passivity-based control technique to control the pressure dynamics in the fuel delivery subsystem of proton exchange membrane fuel cells. The fuel cell stack is a distributed parameter model which can be modeled by partial differential equations. In this paper, the segmentation concept is used to approximate the partial differential equations model by ordinary differential equations model. Therefore, each segment is having multiple ordinary differential equations to obtain the lump-sum model of the segments. Subsequently, a generalized multi-input multi-output lumped parameters model is developed in port-Hamiltonian framework based on mass balance to minimize the modeling error. The modeling errors arise due to the difference between spatially distributed pressures in the segments, and also due to the difference between the actual stack pressure and the measured output pressure of the anode. The segments interconnection feasibility is ensured by maintaining passivity of each segment. With consideration of re-circulation and bleeding of the anode in the modeling, an extended energy-shaping and output tracking state-feedback controller is proposed to control the spatially distributed pressure dynamics in the anode. Furthermore, a sliding mode observer of high order is designed to estimate the unmeasurable pressures with known disturbances. Performance recovery of output feedback control is accomplished with explicit stability analysis. The effectiveness of the proposed control approach is validated by the simulation results.</p></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141961543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}