{"title":"On discrete-time bilinear systems: Constant disturbances enhancing controllability","authors":"Lingxiang Cheng , Lin Tie","doi":"10.1016/j.sysconle.2025.106172","DOIUrl":null,"url":null,"abstract":"<div><div>Disturbances often influence the properties of control systems, which need to be avoided or dealt with by methods of, for instance, robust control and sliding mode control. Whether disturbances destroy controllability of control systems is an important issue. For linear systems, it can be proved that disturbances do not influence controllability. However, for nonlinear systems, it is shown in this paper that disturbances may not destroy controllability but may even enhance it. More specifically, discrete-time commutative bilinear systems are first considered, and it is proved that such uncontrollable systems can be controllable when disturbances appear in the dynamics. Algebraic as well as geometric criteria for controllability of the discrete-time commutative bilinear systems with disturbances are derived, which are both necessary and sufficient conditions. Moreover, an algorithm for computing the required control inputs to achieve state transitions is also proposed. Finally, controllability of general discrete-time bilinear systems with disturbances is studied, which further demonstrates our observation on disturbances enhancing controllability. Examples are provided to illustrate the obtained algebraic controllability criteria and algorithm.</div></div>","PeriodicalId":49450,"journal":{"name":"Systems & Control Letters","volume":"204 ","pages":"Article 106172"},"PeriodicalIF":2.5000,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Systems & Control Letters","FirstCategoryId":"94","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167691125001549","RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"AUTOMATION & CONTROL SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
Disturbances often influence the properties of control systems, which need to be avoided or dealt with by methods of, for instance, robust control and sliding mode control. Whether disturbances destroy controllability of control systems is an important issue. For linear systems, it can be proved that disturbances do not influence controllability. However, for nonlinear systems, it is shown in this paper that disturbances may not destroy controllability but may even enhance it. More specifically, discrete-time commutative bilinear systems are first considered, and it is proved that such uncontrollable systems can be controllable when disturbances appear in the dynamics. Algebraic as well as geometric criteria for controllability of the discrete-time commutative bilinear systems with disturbances are derived, which are both necessary and sufficient conditions. Moreover, an algorithm for computing the required control inputs to achieve state transitions is also proposed. Finally, controllability of general discrete-time bilinear systems with disturbances is studied, which further demonstrates our observation on disturbances enhancing controllability. Examples are provided to illustrate the obtained algebraic controllability criteria and algorithm.
期刊介绍:
Founded in 1981 by two of the pre-eminent control theorists, Roger Brockett and Jan Willems, Systems & Control Letters is one of the leading journals in the field of control theory. The aim of the journal is to allow dissemination of relatively concise but highly original contributions whose high initial quality enables a relatively rapid review process. All aspects of the fields of systems and control are covered, especially mathematically-oriented and theoretical papers that have a clear relevance to engineering, physical and biological sciences, and even economics. Application-oriented papers with sophisticated and rigorous mathematical elements are also welcome.