Automatica最新文献_第3页

Securing voltage stability in power grids via holomorphic dynamics

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-14 DOI: 10.1016/j.automatica.2025.112158

Bai Cui , Xu Andy Sun

{"title":"Securing voltage stability in power grids via holomorphic dynamics","authors":"Bai Cui , Xu Andy Sun","doi":"10.1016/j.automatica.2025.112158","DOIUrl":"10.1016/j.automatica.2025.112158","url":null,"abstract":"<div><div>Voltage instability is a complex dynamic phenomenon in today’s electric power systems. The onset of voltage instability is usually related to the loss of proper solutions to the nonlinear power flow equations, which express the fundamental law governing electric power and voltages in a power grid. Thus, studying the solvability of the power flow equations is at the heart of the voltage stability problem. In this paper, we transform the solvability problem of the power flow equations to a stability problem of a discrete dynamical system defined by a holomorphic mapping in several complex variables. Then, we show a general result on the fixed points of holomorphic functions invariant in a polydisc. Using these analytical tools, we obtain a strong explicit condition that certifies the existence and uniqueness of a proper solution to the nonlinear power flow equations. The new condition reveals in a precise way the interplay between voltage instability, the electrical and topological structures of the power grid, and the electric load characteristics. The new condition is proven to be stronger than existing ones. Extensive computational experiments further demonstrate the strength of the proposed condition for securing real-time voltage stability of large-scale high-voltage electric transmission systems.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"176 ","pages":"Article 112158"},"PeriodicalIF":4.8,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143629104","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}

引用次数: 0

Joint opacity and opacity against state-estimate-intersection-based intrusion of discrete-event systems

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-14 DOI: 10.1016/j.automatica.2025.112136

K. Ritsuka , Stéphane Lafortune , Feng Lin

引用次数: 0

Optimal control over Markovian wireless communication channels under generalized packet dropout compensation

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-12 DOI: 10.1016/j.automatica.2025.112240

Yuriy Zacchia Lun , Francesco Smarra , Alessandro D’Innocenzo

引用次数: 0

Bearing-only solution for Fermat–Weber location problem: Generalized algorithms

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-11 DOI: 10.1016/j.automatica.2025.112242

Nhat-Minh Le-Phan , Phuoc Doan Nguyen , Hyo-Sung Ahn , Minh Hoang Trinh

引用次数: 0

Rank resilience of pattern matrices against structured perturbations with applications

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-10 DOI: 10.1016/j.automatica.2025.112236

Yuan Zhang, Yuanqing Xia, Gang Wang

{"title":"Rank resilience of pattern matrices against structured perturbations with applications","authors":"Yuan Zhang, Yuanqing Xia, Gang Wang","doi":"10.1016/j.automatica.2025.112236","DOIUrl":"10.1016/j.automatica.2025.112236","url":null,"abstract":"<div><div>In structured system theory, a pattern matrix is a matrix with entries either fixed to zero or free to take arbitrary numbers. The (generic) rank of a pattern matrix is the rank of almost all its realizations. The resilience of various system properties is closely tied to the rank resilience of the corresponding pattern matrices. Yet, existing literature predominantly explores the latter aspect by focusing on perturbations that change the zero–nonzero structure of pattern matrices, corresponding to link additions/deletions. In this paper, we consider the rank resilience of pattern matrices against structured perturbations that can arbitrarily alter the values of a prescribed set of entries, corresponding to link weight variations. We say a pattern matrix is structurally rank <span><math><mi>r</mi></math></span> resilient against a perturbation pattern if almost all realizations of this pattern matrix have a rank not less than <span><math><mi>r</mi></math></span> under arbitrary complex-valued realizations of the perturbation pattern. We establish a generic property in this concept. We then present combinatorial necessary and sufficient conditions for a rectangular pattern matrix to lose full rank under given perturbation patterns. We also generalize them to obtain a sufficient condition and a necessary one for losing an arbitrarily prescribed rank. We finally show our results can be applied to the resilience analysis of various properties of structured (descriptor) systems, including controllability and input-state observability, as well as characterizing zero structurally fixed modes.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"176 ","pages":"Article 112236"},"PeriodicalIF":4.8,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580282","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}

引用次数: 0

Verification of current-state opacity and opaque time for labeled time Petri net systems

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-09 DOI: 10.1016/j.automatica.2025.112241

Yuting Wang , Liang Li , Zhiwu Li

{"title":"Verification of current-state opacity and opaque time for labeled time Petri net systems","authors":"Yuting Wang , Liang Li , Zhiwu Li","doi":"10.1016/j.automatica.2025.112241","DOIUrl":"10.1016/j.automatica.2025.112241","url":null,"abstract":"<div><div>This paper investigates the verification of current-state opacity and opaque time in timed discrete event systems modeled with labeled time Petri nets (LTPNs). First, we formally conceptualize current-state opacity and opaque time for LTPN systems. Based on the solution of a set of linear programming problems (LPPs) associated with the transitions-related timing constraints in the modified state class graph (MSCG) of an LTPN system, an approach is proposed to find all the state classes and logic transition sequences that the system may generate at a given time instant. By utilizing such state classes and logic transition sequences, a method for verifying the current-state opacity of an LTPN system is presented, avoiding an exhaustive enumeration of the state classes that are consistent with all the observable label sequences at the time instant. To further acquire the current-state opaque time of the LTPN system, we propose a method for calculating the length of opaque time based on the solution of LPPs that are associated with the paths in the MSCG. Particularly, an algorithm is reported to compute the opaque time of an LTPN system with respect to a given secret. Finally, a case study is provided to illustrate the proposed algorithms to determine the current-state opacity and opaque time for an LTPN system.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"176 ","pages":"Article 112241"},"PeriodicalIF":4.8,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580281","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}

引用次数: 0

Probabilistic reachable sets of stochastic nonlinear systems with contextual uncertainties

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-06 DOI: 10.1016/j.automatica.2025.112237

Xun Shen , Ye Wang , Kazumune Hashimoto , Yuhu Wu , Sebastien Gros

{"title":"Probabilistic reachable sets of stochastic nonlinear systems with contextual uncertainties","authors":"Xun Shen , Ye Wang , Kazumune Hashimoto , Yuhu Wu , Sebastien Gros","doi":"10.1016/j.automatica.2025.112237","DOIUrl":"10.1016/j.automatica.2025.112237","url":null,"abstract":"<div><div>Validating and controlling safety-critical systems in uncertain environments necessitates probabilistic reachable sets of future state evolutions. The existing methods of computing probabilistic reachable sets normally assume that stochastic uncertainties are independent of system states, inputs, and other environment variables. However, this assumption falls short in many real-world applications, where the probability distribution governing uncertainties depends on these variables, referred to as <em>contextual uncertainties</em>. This paper addresses the challenge of computing probabilistic reachable sets of stochastic nonlinear states with contextual uncertainties by seeking minimum-volume polynomial sublevel sets with contextual chance constraints. The formulated problem cannot be solved by the existing sample-based approximation method since the existing methods do not consider conditional probability densities. To address this, we propose a consistent sample approximation of the original problem by leveraging conditional density estimation and resampling. The obtained approximate problem is a tractable optimization problem. Additionally, we prove the proposed sample-based approximation’s almost uniform convergence, showing that it gives the optimal solution almost consistently with the original ones. Through a numerical example, we evaluate the effectiveness of the proposed method against existing approaches, highlighting its capability to significantly reduce the bias inherent in sample-based approximation without considering a conditional probability density.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"176 ","pages":"Article 112237"},"PeriodicalIF":4.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143563702","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}

引用次数: 0

Maximizing the smallest eigenvalue of grounded Laplacian matrices via edge addition

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-06 DOI: 10.1016/j.automatica.2025.112238

Xinfeng Ru , Weiguo Xia , Ming Cao

{"title":"Maximizing the smallest eigenvalue of grounded Laplacian matrices via edge addition","authors":"Xinfeng Ru , Weiguo Xia , Ming Cao","doi":"10.1016/j.automatica.2025.112238","DOIUrl":"10.1016/j.automatica.2025.112238","url":null,"abstract":"<div><div>The smallest eigenvalue of the grounded Laplacian matrix holds pivotal significance across various practical scenarios, particularly in characterizing the convergence rate of leader–follower networks in multi-agent systems, with a larger smallest eigenvalue indicating a faster convergence rate. This paper focuses on maximizing the smallest eigenvalue of the grounded Laplacian matrix via adding edges for both undirected and directed networks. For undirected networks, under intuitive conditions, we prove that adding one edge between two vertices that correspond to the smallest and largest eigenvector components for the smallest eigenvalue will maximize the smallest eigenvalue of the grounded Laplacian matrix. In addition, the discussion is extended to the case of multiple edge addition, where a suboptimal algorithm is proposed to maximize the eigenvalue with a low time complexity. For directed networks, when fixing a vertex <span><math><mi>i</mi></math></span> and adding an edge pointing to it, choosing the vertex, if there is any, that has the smallest eigenvector component than that of <span><math><mi>i</mi></math></span> leads to the maximal increase of the smallest eigenvalue. We apply the derived results to the distributed neighbor selection for directed networks.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"176 ","pages":"Article 112238"},"PeriodicalIF":4.8,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551413","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}

引用次数: 0

Properties of immersions for systems with multiple limit sets with implications to learning Koopman embeddings

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-05 DOI: 10.1016/j.automatica.2025.112226

Zexiang Liu , Necmiye Ozay , Eduardo D. Sontag

引用次数: 0

Generic diagonalizability, structural functional observability and output controllability

IF 4.8 2区计算机科学

Automatica Pub Date : 2025-03-03 DOI: 10.1016/j.automatica.2025.112232

Yuan Zhang , Tyrone Fernando , Mohamed Darouach

{"title":"Generic diagonalizability, structural functional observability and output controllability","authors":"Yuan Zhang , Tyrone Fernando , Mohamed Darouach","doi":"10.1016/j.automatica.2025.112232","DOIUrl":"10.1016/j.automatica.2025.112232","url":null,"abstract":"<div><div>This paper investigates the structural functional observability (SFO) and structural output controllability (SOC) of a class of systems and explores the associated minimal sensor and actuator placement problems. The verification of SOC and the corresponding sensor and actuator placement problems, i.e., the problems of determining the minimum number of outputs and inputs required to achieve SFO and SOC, respectively, are yet open for general systems. This motivates our focus on a large class of systems enabling polynomial-time solutions. In this line, we first define and characterize generically diagonalizable systems, referring to structured systems for which almost all realizations of the state matrices are diagonalizable. We then develop computationally efficient criteria for SFO and SOC within the context of generically diagonalizable systems. Our work expands the class of systems amenable to polynomial-time SOC verification. Thanks to the simplicity of the obtained criteria, we derive closed-form solutions for determining the minimal sensor placement to achieve SFO and the minimal actuator deployment to achieve SOC in such systems, along with efficient weighted maximum matching-based and weighted maximum flow-based algorithms. For more general systems to achieve SFO, we establish an upper bound on the number of required sensors by identifying a non-decreasing property of SFO with respect to a specific class of edge additions, which is proven to be optimal under certain conditions.</div></div>","PeriodicalId":55413,"journal":{"name":"Automatica","volume":"176 ","pages":"Article 112232"},"PeriodicalIF":4.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551407","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}

引用次数: 0