Automatica最新文献

{"title":"Neural operators for adaptive control of freeway traffic","authors":"Kaijing Lv ,&nbsp;Junmin Wang ,&nbsp;Yihuai Zhang ,&nbsp;Huan Yu","doi":"10.1016/j.automatica.2025.112553","DOIUrl":"10.1016/j.automatica.2025.112553","url":null,"abstract":"<div><div>The uncertainty in human driving behaviors leads to stop-and-go traffic congestion on freeway. The freeway traffic dynamics are governed by the Aw–Rascle–Zhang (ARZ) traffic Partial Differential Equation (PDE) models with unknown relaxation time. Motivated by the adaptive traffic control problem, this paper presents a neural operator (NO) based adaptive boundary control design for the coupled 2 × 2 hyperbolic systems with uncertain spatially varying in-domain coefficients and boundary parameter. In traditional adaptive control for PDEs, solving backstepping kernel online can be computationally intensive, as it updates the estimation of coefficients at each time step. To address this challenge, we use operator learning, i.e. DeepONet, to learn the mapping from system parameters to the kernels functions. DeepONet, a class of deep neural networks designed for approximating operators, has shown strong potential for approximating PDE backstepping designs in recent studies. Unlike previous works that focus on approximating single kernel equation associated with the scalar PDE system, we extend this framework to approximate PDE kernels for a class of the first-order coupled 2 × 2 hyperbolic kernel equations. Our approach demonstrates that DeepONet is nearly two orders of magnitude faster than traditional PDE solvers for generating kernel functions, while maintaining a loss on the order of <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span>. In addition, we rigorously establish the system’s stability via Lyapunov analysis when employing DeepONet-approximated kernels in the adaptive controller. The proposed adaptive control is compared with reinforcement learning (RL) methods. Our approach guarantees stability and does not rely on initial values, which is essential for rapidly changing traffic scenarios. This is the first time this operator learning framework has been applied to the adaptive control of the ARZ traffic model, significantly enhancing the real-time applicability of this design framework for mitigating traffic congestion.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112553"},"PeriodicalIF":5.9,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888936","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":"Covert attack detection for cyber-physical systems using input-associated watermarking mechanism","authors":"Haijing Fu,&nbsp;Bo Shen,&nbsp;Lei Zou","doi":"10.1016/j.automatica.2025.112516","DOIUrl":"10.1016/j.automatica.2025.112516","url":null,"abstract":"<div><div>In this paper, a novel covert attack detector is developed for cyber–physical systems by using input-associated watermarking mechanism. Covert attacks are very sophisticated and rely on perfect model knowledge, so that the generated attack signals have no response in the measurement output and thus evades the standard <span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> detector. A necessary and sufficient condition and a sufficient condition are respectively presented for the stealthiness and destructiveness of covert attacks for the purpose of revealing the features of covert attacks. Then, a novel input-associated watermarking mechanism is developed to assist <span><math><msup><mrow><mi>χ</mi></mrow><mrow><mn>2</mn></mrow></msup></math></span> detector to “expose” the attack behaviors in the detection process. Intensive analysis is subsequently implemented on the resultant attack detection rate under the proposed detection mechanism. It is worth emphasizing that the developed detection mechanism does not sacrifice the estimation performance under the attack-free situation. Furthermore, the designed proactive detection method is extended to the detection for the so-called zero dynamics attacks. Ultimately, a simulation example is utilized to illustrative the usefulness and effectiveness of the proposed input-associated watermarking mechanism.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112516"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144888937","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":"Online distributed optimization with clipped stochastic gradients: High probability bound of regrets","authors":"Yuchen Yang ,&nbsp;Kaihong Lu ,&nbsp;Long Wang","doi":"10.1016/j.automatica.2025.112525","DOIUrl":"10.1016/j.automatica.2025.112525","url":null,"abstract":"<div><div>In this paper, the problem of online distributed optimization is studied via a network of agents. Each agent only has access to a stochastic gradient of its own objective function in the previous time, and can communicate with its neighbors via a time-varying network. To handle this problem, an online distributed clipped stochastic gradient descent algorithm is proposed. Dynamic regrets are used to capture the performance of the algorithm. Particularly, the high probability bounds of the regrets are analyzed when the stochastic gradients satisfy the heavy-tailed noise condition. For the convex case, the offline benchmark of the dynamic regret is to seek the minimizer of the objective function each time. Under mild assumptions on the graph connectivity, we prove that the dynamic regret grows sublinearly with high probability under a certain clipping parameter. For the non-convex case, the offline benchmark of the dynamic regret is to find the stationary point of the objective function each time. We show that the dynamic regret increases sublinearly with high probability if the variation of the objective function grows within a certain rate. Finally, numerical simulations are provided to demonstrate the effectiveness of our theoretical results.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112525"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887436","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":"Fixed-time switching control of a turbofan aero-engine under non-ideal parameters","authors":"Zhen Wu ,&nbsp;Zhongyang Fei ,&nbsp;Xuefang Lin-Shi","doi":"10.1016/j.automatica.2025.112533","DOIUrl":"10.1016/j.automatica.2025.112533","url":null,"abstract":"<div><div>This paper proposes a fixed-time switching control method for a turbofan aero-engine under non-ideal parameters. First, the time cost of the mode identification is considered, which results in the controller parameters not always being best suited to the aero-engine in each operating mode. Second, the fixed-time disturbance observer and fixed-time feedback control law are newly designed to estimate and compensate the total disturbance, respectively, for achieving the closed-loop tracking. The reliance on an accurate system model is mitigated in the controller design. Third, novel criteria are proposed to ensure the fixed-time stability of the estimation error system and the closed-loop system, respectively, under non-ideal parameters. Finally, superiorities of the proposed method are verified through its applications to a double-spool turbofan aero-engine. Experimental results validate that the proposed method offers faster response speed and stronger robustness, which significantly improves the transient control performance.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112533"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887435","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":"Optimal DoS attack and proactive deception strategies on remote state estimation: Utilizing subsystem importance","authors":"Hanxiao Liu ,&nbsp;Kemi Ding ,&nbsp;Lihua Xie","doi":"10.1016/j.automatica.2025.112522","DOIUrl":"10.1016/j.automatica.2025.112522","url":null,"abstract":"<div><div>This paper tackles security challenges in remote state estimation for cyber–physical systems (CPSs) with a focus on an importance-based denial-of-service (DoS) attack over an infinite time horizon. We employ the concept of “importance” to quantify the criticality of subsystem information for decision efficiency, establishing a correlation between importance and transmission power allocated to each subsystem’s channel. We establish the existence of an optimal attack policy and analyze its structural properties. Additionally, we investigate proactive deception strategies that manipulate transmission power to mislead attackers about the importance of subsystems. Within a Stackelberg game framework, we propose and analyze a proactive deception strategy tailored against importance-based DoS attacks, along with an algorithm to obtain the optimal strategy. Finally, we provide numerical examples to illustrate the theoretical results and demonstrate the practical implications of our proposed strategies for enhancing security in remote state estimation for CPSs.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112522"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887453","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 Koopman-backstepping approach to data-driven robust output regulation for linear parabolic systems","authors":"Joachim Deutscher,&nbsp;Julian Zimmer","doi":"10.1016/j.automatica.2025.112538","DOIUrl":"10.1016/j.automatica.2025.112538","url":null,"abstract":"<div><div>In this paper a solution of the data-driven robust output regulation problem for linear parabolic systems is presented. Both the system as well as the ODE, i.e., the disturbance model, describing the disturbances are unknown, but finite-time sequential data obtained from measurements of the output to be controlled and additional boundary outputs are available. The data-driven controller is designed in the Koopman operator framework for PDEs, where the Koopman modes and eigenvalues are obtained from data using Hankel-DMD. It is shown that all system parameters and the eigenvalues of the disturbance model can be recovered from the available measurements by solving an inverse Sturm–Liouville problem. This allows to directly apply backstepping methods for the robust regulator design. For this, closed-loop stability in the presence of small errors in the Hankel-DMD is verified in the nominal case. Robust output regulation is shown for non-destabilizing model uncertainties. A numerical example demonstrates the results of the paper.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112538"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887504","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":"Accurate prescribed-time output consensus of heterogeneous multi-agent systems: A bounded time-varying gain approach","authors":"Hongpeng Li ,&nbsp;Xinchun Jia ,&nbsp;Suna Duan ,&nbsp;Xiaobo Chi","doi":"10.1016/j.automatica.2025.112546","DOIUrl":"10.1016/j.automatica.2025.112546","url":null,"abstract":"<div><div>In this paper, we develop a bounded time-varying gain approach, consisting of a time base generator (TBG)-based observer and a switching controller, to achieve the accurate prescribed-time output consensus for heterogeneous multi-agent systems (MASs). First, the TBG-based observer is designed for each agent to estimate the leader’s state, and the accurate estimation time can be pre-set arbitrarily. Next, a switching controller is designed, which integrates a TBG-based time-varying feedback and a fractional-order feedback, with a pre-determined switching instant before a prescribed time. Under this switching controller, the accurate prescribed-time output consensus of heterogeneous MASs is achieved, irrespective of agents’ initial states and control parameters. The bounded nature of the TBG gain within the prescribed time interval ensures that the proposed switching controller is non-singular, avoiding the numerical calculation problem associated with unbounded time-varying gains. Moreover, a control optimization algorithm is introduced to select the optimal switching instant, thus solving the accurate prescribed-time output consensus for heterogeneous MASs with minimal control effort. Notably, the proposed approach does not require a temporal scale transformation of the prescribed time intervals and state variables of all agents, simplifying the analysis process. Finally, the theoretical results are validated through a simulation example.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112546"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887437","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":"Exact controllability of discrete-time stochastic system with multiplicative noise and control constraint","authors":"Juanjuan Xu ,&nbsp;Huanshui Zhang ,&nbsp;Minyue Fu ,&nbsp;Wenjing Wang","doi":"10.1016/j.automatica.2025.112519","DOIUrl":"10.1016/j.automatica.2025.112519","url":null,"abstract":"<div><div>In this paper, we study the exact controllability of discrete-time linear time-varying stochastic systems with multiplicative noise. In particular, the controllers are constrained in a bounded set. The main contribution is to present the necessary and sufficient condition for the control constrained controllability in terms of the divergence of an infinite series. Furthermore, we propose some sufficient conditions to verify the control constrained controllability. The key is to decouple the diffusion term by using one part of the controller and drive a backward stochastic system with zero terminal value to arbitrary initial value by designing the other part of the controller. Numerical examples demonstrate the effectiveness of the results.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112519"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887503","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":"Identification of non-causal systems with random switching modes","authors":"Yanxin Zhang ,&nbsp;Chengpu Yu ,&nbsp;Filippo Fabiani","doi":"10.1016/j.automatica.2025.112532","DOIUrl":"10.1016/j.automatica.2025.112532","url":null,"abstract":"<div><div>We consider the identification of non-causal systems with random switching modes (NCS-RSM), a class of models essential for describing typical power load management and department store inventory dynamics. The simultaneous identification of causal-and-anticausal subsystems, along with the presence of random switching sequences, however, make the overall identification problem particularly challenging. To this end, we develop an expectation–maximization (EM) based system identification technique, where the E-step proposes a modified Kalman filter (KF) to estimate the states and switching sequences of causal-and-anticausal subsystems, while the M-step consists in a switching least-squares algorithm to estimate the parameters of individual subsystems. We establish the main convergence features of the proposed identification procedure, also providing bounds on the parameter estimation errors under mild conditions. Finally, the effectiveness of our identification method is validated through two numerical simulations.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112532"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887451","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":"Generalizations of data-driven balancing: What to sample for different balancing-based reduced models","authors":"Sean Reiter ,&nbsp;Ion Victor Gosea ,&nbsp;Serkan Gugercin","doi":"10.1016/j.automatica.2025.112518","DOIUrl":"10.1016/j.automatica.2025.112518","url":null,"abstract":"<div><div>The quadrature-based balanced truncation (<span>QuadBT</span>) framework of Gosea et al. (2022) is a non-intrusive reformulation of balanced truncation (<span>BT</span>), a classical projection-based model-order reduction technique for linear systems. <span>QuadBT</span> is non-intrusive in the sense that it builds approximate balanced truncation reduced-order models entirely from system response data, e.g., transfer function measurements, without the need to reference an explicit state-space realization of the underlying full-order model. In this work, we generalize the <span>QuadBT</span> framework to other types of balanced truncation model reduction. Namely, we show what transfer function data are required to compute data-driven reduced models by balanced stochastic truncation, positive-real balanced truncation, and bounded-real balanced truncation. In each case, these data are evaluations of particular spectral factors associated with the system of interest. These results lay the theoretical foundation for data-driven reformulations of the aforementioned <span>BT</span> variants. Although it is not yet clear how to compute or obtain these spectral factor data in a practical real-world setting, examples using synthetic (numerically evaluated) transfer function data are included to validate the data-based reduced models.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"182 ","pages":"Article 112518"},"PeriodicalIF":5.9,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144887433","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}