{"title":"Two-stage parameter estimation methods for linear time-invariant continuous-time systems","authors":"Feng Ding , Ling Xu , Peng Liu , Xianfang Wang","doi":"10.1016/j.sysconle.2025.106166","DOIUrl":"10.1016/j.sysconle.2025.106166","url":null,"abstract":"<div><div>This paper considers the parameter estimation problems of general linear time-invariant continuous-time systems described by higher-order constant coefficient differentiate equations. This paper derives the two-stage parameter estimation model of the systems, which contains two parameter vectors, one corresponds to the coefficients of the denominator polynomial of the transfer function and the other corresponds to the coefficients of the numerator polynomial of the transfer function. Furthermore, we propose two-stage projection estimation algorithm, two-stage generalized projection estimation algorithm, two-stage stochastic gradient estimation algorithm, two-stage recursive least squares estimation algorithm and their variants. The proposed algorithms can be extended to investigate the parameter estimation of other linear stochastic systems with colored noises.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106166"},"PeriodicalIF":2.1,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633010","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":"An adaptive gain-based fixed-time distributed algorithm for constrained optimization problems","authors":"Xiasheng Shi , Zhiyun Lin , Yanjun Lin","doi":"10.1016/j.sysconle.2025.106189","DOIUrl":"10.1016/j.sysconle.2025.106189","url":null,"abstract":"<div><div>This letter presents a novel adaptive gain-based fixed-time distributed algorithm for solving constrained optimization problems in continuous-time multi-agent systems (MASs). The proposed approach first introduces a sliding mode control scheme with an adaptive control parameter to ensure the satisfaction of coupled equality constraints within a fixed time, regardless of the initial state. Based on this scheme, an innovative node-based distributed optimization algorithm is developed, incorporating a nonlinear adaptive consensus scheme to achieve the optimal solution within a fixed time. The theoretical upper bound for the convergence time is determined by the first positive zero point of a sine function. Furthermore, the algorithm is extended to an edge-based distributed optimization scheme to reduce communication burden, albeit with increased memory consumption. Lyapunov technique is employed to confirm the stability of both the node-based and edge-based methods. To address the singularity issues encountered in the adaptive fixed-time algorithms, the saturation function and the power-ball method are introduced. Finally, the effectiveness and superior convergence performance of the proposed methods are demonstrated through three simulation cases, particularly highlighting their advantages in scenarios with sparse communication networks.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106189"},"PeriodicalIF":2.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144631559","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}
Nicholas A. Corbin , Arijit Sarkar , Jacquelien M.A. Scherpen , Boris Kramer
{"title":"Scalable computation of input-normal/output-diagonal balanced realization for control-affine polynomial systems","authors":"Nicholas A. Corbin , Arijit Sarkar , Jacquelien M.A. Scherpen , Boris Kramer","doi":"10.1016/j.sysconle.2025.106178","DOIUrl":"10.1016/j.sysconle.2025.106178","url":null,"abstract":"<div><div>We present a scalable tensor-based approach to computing input-normal/output-diagonal nonlinear balancing transformations for control-affine systems with polynomial nonlinearities. This transformation is necessary to determine the states that can be truncated when forming a reduced-order model. Given a polynomial representation for the controllability and observability energy functions, we derive the explicit equations to compute a polynomial transformation to induce input-normal/output-diagonal structure in the energy functions in the transformed coordinates. The transformation is computed degree-by-degree, similar to previous Taylor-series approaches in the literature. However, unlike previous works, we provide a detailed analysis of the transformation equations in Kronecker product form to enable a more scalable implementation. We derive the explicit algebraic structure for the equations, present rigorous analyses for the solvability and algorithmic complexity of those equations, and provide general purpose open-source software implementations for the proposed algorithms to stimulate broader use of nonlinear balanced truncation model reduction. We demonstrate that with our efficient implementation, computing the nonlinear transformation is approximately as expensive as computing the energy functions using state-of-the-art methods.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106178"},"PeriodicalIF":2.1,"publicationDate":"2025-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633009","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":"A time advantage function-based solution to two-player circular target defense games","authors":"Keyang Wang , Peng Chang , Qi Sun , Yintao Wang","doi":"10.1016/j.sysconle.2025.106197","DOIUrl":"10.1016/j.sysconle.2025.106197","url":null,"abstract":"<div><div>This paper investigates a two-player circular target defense game where a defender, constrained to the target boundary, protects the target region from an intruder. The study incorporates limited observation capabilities for both agents, deriving conditions under which the defender can intercept the intruder or the intruder can breach the target. This work formulates the problem as a Game of Kind, introducing a time advantage function that quantifies the game outcome: when the function is non-negative, the intruder dominates the game, selecting an invasion point on the target boundary that maximizes the time advantage (maximizing terminal separation from the defender) to ensure successful penetration; when the function is negative, the defender strategically deviates from the target boundary and utilizes the boundary of dominance region (defined by intersections of the agent isochrones) to derive optimal interception trajectories. Numerical simulations validate the proposed method, demonstrating how the time advantage function enables clear winner determination and strategy derivation, bridging theoretical game theory with practical sensing constraints.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106197"},"PeriodicalIF":2.1,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614597","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}
F.W. Chaves-Silva , N. Carreño , M.G. Ferreira-Silva
{"title":"On the controllability of parabolic equations with large parameters in small time","authors":"F.W. Chaves-Silva , N. Carreño , M.G. Ferreira-Silva","doi":"10.1016/j.sysconle.2025.106177","DOIUrl":"10.1016/j.sysconle.2025.106177","url":null,"abstract":"<div><div>In this work, we deal with the heat equation perturbed by an anomalous diffusion term scaled by a large parameter. More precisely, we study the cost of null controllability for the system as the parameter goes to infinity. We show that is possible to construct null controls that exhibit exponential decay with respect to the parameter. Our study gives a positive answer to a conjecture raised by J.-L. Lions and E. Zuazua [Rev. Mat. Univ. Complut. Madrid, 10 (2)(1997), 481-524]. Additionally, using the so-called source term method and an inverse mapping theorem, we prove that it is possible to achieve controllability results for certain nonlinear systems with a control with a cost decaying to zero as well.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106177"},"PeriodicalIF":2.1,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614542","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":"Neural operators in backstepping control for hyperbolic partial differential equations (PDEs) in rotary drilling systems","authors":"Samir Toumi","doi":"10.1016/j.sysconle.2025.106191","DOIUrl":"10.1016/j.sysconle.2025.106191","url":null,"abstract":"<div><div>Designing controllers for partial differential equations (PDEs), such as backstepping controllers, requires mapping system model functions into gain functions. These mappings involve infinite-dimensional nonlinear operators, typically defined through PDEs with spatial variables. For each new coefficient of the PDE, a corresponding gain function must be determined by solving these complex equations. However, this challenge can be addressed by employing a neural operator to learn and approximate the mapping efficiently. In this context, this paper focuses on stabilizing torsional vibrations caused by bit stick–slip behavior in oilwell drilling systems, which are described by a damped wave equation. To achieve this, the second-order torsional vibration dynamics are transformed into a coupled system of <span><math><mrow><mn>2</mn><mo>×</mo><mn>2</mn></mrow></math></span> first-order PDEs. Building on this formulation, we verify the continuity of the mapping from the plant PDE coefficients to the solutions of the kernel PDEs and show that a DeepONet approximation closely mirrors the exact kernel PDEs. Furthermore, we demonstrate that the DeepONet-approximated gains ensure system stabilization, effectively replacing the exact backstepping gain kernels. The stabilizing capability of the proposed approach is supported by theoretical proofs and validated through simulation results. This study extends the work by Toumiet al. (2017).</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106191"},"PeriodicalIF":2.1,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613947","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":"Path integral control of partially observed systems via fully observable control approximations","authors":"Kenta Hoshino , Hongzhe Yu , Takashi Tanaka , Yongxin Chen","doi":"10.1016/j.sysconle.2025.106185","DOIUrl":"10.1016/j.sysconle.2025.106185","url":null,"abstract":"<div><div>This study considers a partially observed optimal control problem in which the state is measured through a noisy output, focusing on continuous-time and continuous-space settings. To develop a control algorithm for this challenging problem, we extend the so-called fully observable value approximation, originally developed for the partially observable Markov decision problems (POMDPs) in discrete-time and discrete-space domains, to the continuous ones. The approximation yields a suboptimal controller with a structure analogous to that of a controller obtained through the separation principle for the so-called linear-quadratic settings. Combined with the path integral control method, the proposed extension allows for a suboptimal policy synthesis for partially observable systems. Numerical experiments demonstrate the effectiveness of the proposed algorithm in handling partially observable control problems of continuous-time, continuous-space, and nonlinear systems.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106185"},"PeriodicalIF":2.1,"publicationDate":"2025-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144613948","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}
Jiacheng Chen , Dan Goreac , Juan Li , Oana-Silvia Serea
{"title":"LP techniques in the control of reflected jump systems and their relevance for epidemics","authors":"Jiacheng Chen , Dan Goreac , Juan Li , Oana-Silvia Serea","doi":"10.1016/j.sysconle.2025.106195","DOIUrl":"10.1016/j.sysconle.2025.106195","url":null,"abstract":"<div><div>Our brief paper primarily focuses on the control of reflected stochastic differential equations (SDE) with jumps. The illustrations on data on COVID-19 (INSEE, France) suggest that reflected jump models capture interesting features: successive infection waves due to waning immunity and increased efficacy of social-distancing over vaccination-only policies. The price to pay when considering reflected dynamics is an increase of difficulty to treat the control issues. To address this, the core of the paper focuses on linear programming (LP) techniques in the control of such reflected SDEs of jump type.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106195"},"PeriodicalIF":2.1,"publicationDate":"2025-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597046","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":"Consensus of heterogeneous multi-agent system in switching network using model predictive control","authors":"Shibo Han, Chong Jin Ong","doi":"10.1016/j.sysconle.2025.106187","DOIUrl":"10.1016/j.sysconle.2025.106187","url":null,"abstract":"<div><div>This work shows an approach to achieve output consensus among heterogeneous agents in a multi-agent environment where each agent is an uncertain linear system subject to input and state constraints. The communication among agents is described by a time-varying directed graph with bounded communication delays. The approach relies on achieving consensus among the references of the agents and that each agent has a Model Predictive Controller (MPC) that tracks piecewise constant references asymptotically. A notable contribution is the characterization of the trackable references for every agents. This set of trackable references for each agent is used to ensure output consensus for all agents. Since consensus is imposed on the references, the recursive feasibility condition of MPC can be easily satisfied. The choice of the control parametrization also allows for a large domain of applicability. Examples are provided to illustrate the advantages of the approach.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106187"},"PeriodicalIF":2.1,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588259","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}
Shuo Zhang , Lei Miao , Wei Xing , Xudong Zhao , Lun Li
{"title":"DoS attack schedules for remote state estimation under multi-sensor round-robin protocol","authors":"Shuo Zhang , Lei Miao , Wei Xing , Xudong Zhao , Lun Li","doi":"10.1016/j.sysconle.2025.106190","DOIUrl":"10.1016/j.sysconle.2025.106190","url":null,"abstract":"<div><div>In this paper, we investigate the optimal scheduling of denial-of-service (DoS) attacks for remote state estimation in cyber–physical systems with multiple sensors and channels. To avoid data conflicts, only one of the sensors can access the wireless communication channels and transmit its data packets to the remote estimator which may also experience congestion caused by a malicious DoS attacker. Given the energy limitations of the attackers, decisions must be made at each time step about whether to initiate an attack on the communication channels. We obtain an inherent dynamic characteristic of the error covariance at the remote estimator and propose an optimal attack schedule by concentrating on two scenarios: (i) smart sensors that can execute a Kalman filter algorithm in real time, and (ii) non-intelligent sensors that are restricted to collecting and transmitting only raw measurement data. Finally, the theoretical results are illustrated by numerical examples.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106190"},"PeriodicalIF":2.1,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144588316","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}