Robust stability and stabilization of uncertain switched discrete-time systems (original) (raw)

Stability Analysis of Discrete-time Switched Linear Systems with Parametric Uncertainties

International Journal of Industrial Electronics, Control and Optimization (IECO), 2019

This paper considers the stability problem of discrete-time switched linear systems in the presence of parametric uncertainties. This type of uncertainty is sometimes called structured uncertainty because of its known structure. However, some of the parameters in the system are uncertain. From a practical viewpoint, it is important to guarantee the robust stability of uncertain switched systems. Therefore, based on the structure of the uncertainty matrix and the common Lyapunov function for the nominal switched system, sufficient conditions for robust exponential stability of the discrete-time uncertain switched system (under any switching signal) are derived. These sufficient conditions are formulated in terms of matrix inequalities and using fixed values for some parameters, they will be solved via LMI techniques and based on numerical methods. Moreover, a procedure is proposed to determine the maximum admissible bounds of the uncertain parameters to guarantee the exponential stability of the uncertain switched system. Finally, numerical examples are provided to verify the proposed theoretical results.

Stabilization Through Output Feedback Control for Uncertain Switched Discrete Time Systems

This paper discusses the robust stabilization of discrete switched systems, focusing on the design of a robust static output feedback control and dynamic output control based on a switched observer. The results are derived using the direct Lyapunov approach and the polyquadratic function concept. The stabilization conditions are written through linear matrix inequalities relations. The polyquadratic Lyapunov approach provides a constructive way to tackle uncertainty in the switched framework. The feasibility is illustrated on an example of discrete uncertain switched discrete time system.

Necessary and sufficient condition for stabilizability of discrete-time linear switched systems: A set-theory approach

Automatica, 2014

In this paper, the stabilizability of discrete-time linear switched systems is considered. Several sufficient conditions for stabilizability are proposed in the literature, but no necessary and sufficient. The main contributions are the necessary and sufficient conditions for stabilizability based on set-theory and the characterization of a universal class of Lyapunov functions. An algorithm for computing the Lyapunov functions and a procedure to design the stabilizing switching control law are provided, based on such conditions. Moreover a sufficient condition for non-stabilizability for switched system is presented. Several academic examples are given to illustrate the efficiency of the proposed results. In particular, a Lyapunov function is obtained for a system for which the Lyapunov-Metzler condition for stabilizability does not hold.

A New Switching Strategy for Exponential Stabilization of Uncertain Discrete-Time Switched Linear Systems in Guaranteed Cost Control Problem

Iranian Journal of Electrical and Electronic Engineering

Uncertain switched linear systems are known as an important class of control systems. Performance of these systems is affected by uncertainties and their stabilization is a main concern of recent studies. Existing work on stabilization of these systems only provides asymptotical stabilization via designing switching strategy and state-feedback controller. In this paper, considering a given infinite-horizon cost function, a new switching strategy and a state-feedback control laws are designed to exponentially stabilize Uncertain Discrete-Time Switched Linear Systems (UDSLS). Our design procedure consists of two steps. First, we generalize the exponential stabilization theorem of nonlinear systems into UDSLS. Second, a new stabilizing switching strategy based on the Common Lyapunov Function technique presented. Hence, a sufficient condition on the existence of statefeedback controller is provided in the form of Linear Matrix Inequality. Besides, convergence rate of the states is obtained and the upper bound of the cost is calculated. Finally, effectiveness of the proposed method is verified via numerical example.

Stabilization of Uncertain State Constrained Discrete-Time Switched Systems

Proceedings of the 18th IFAC World Congress, 2011

This paper presents sufficient conditions for the stabilization of constrained switched discretetime linear systems with polytopic uncertainties. A strategy of conception of switched laws from the solution of Lyapunov-Metzler inequalities is developed. Two numerical examples are used to illustrate the proposed technique.

Stability analysis and H∞ controller design of a class of switched discrete-time fuzzy systems

IEEE Conference on Decision and Control and European Control Conference, 2011

In this paper, the problems of stability analysis and H∞ controller design of a class of switched nonlinear systems are investigated. In a classical way, the modeling of the systems is approached by switched fuzzy systems, and both fast switching and slow switching are considered there. In particular, for slow switching scheme, a new mode-dependent average dwell time switching is proposed for the underlying switched fuzzy systems. Based on a fuzzy-basis-dependent and mode-dependent Lyapunov function, the H∞ state-feedback controller is derived. A numerical example is given to show the validity and potential of the theoretical results.

Static switched output feedback stabilization for linear discrete-time switched systems

This paper focuses on the problem of switched static output feedback (SOF) control for discrete-time switched linear systems under arbitrary switching laws. The considered class of systems is characterized by a particular structure of system matrices. Our principle idea is addressed in the derivation of new sufficient linear matrix inequalities conditions for the synthesis of a switched controller for a particular class of switched systems. The adopted methodology is based on the using of a special congruence transformation and a switched quadratic Lyapunov function. We propose important sufficient LMI conditions for SOF stabilization in the general case which guarantee the switchedquadratically stability of the closed-loop system. The various conditions are given through a family of LMI (linear matrix inequalities) parameterized by a scalar variable which offers an additional degree of freedom, enabling, at the expense of a relatively small degree of complexity in the numerical treatment (one line search), to provide better results compared with previous ones in the literature. A numerical example is presented to illustrate the effectiveness of the proposed conditions.

Stabilization of switched discrete-time systems with time-varying delay

2008

A convex approach is proposed to deal with switched discrete-time systems with time-varying delays. It uses a parameter dependent Lyapunov-Krasovskii functional that allows to assure the robust stability or the robust stabilization of a switched system for arbitrary switching functions. The analysis and the design conditions are formulated as simple feasibility tests of linear matrix inequalities (LMIs). The presented conditions encompass previous results found in the literature, yielding less conservative and convex design methods. The design conditions can take into account the rate of variation of delay and deal with decentralized control. A design example is presented to illustrate the efficacy of the proposed LMI conditions, including some time-simulations.

Stabilization of Continuous-time and Discrete-time Switched Systems : A Review *

2017

Stability problem for a class of linear continuous time and discrete time systems is well understood since long. This analysis has also been extended to switched linear systems with continuous and discrete descriptions. For such cases, arbitrary switching problem is addressed by constructing common quadratic and non-quadratic Lyapunov function. Moreover, keeping in view the invertible time delays in dynamical systems due to internal factors or external environment, study of switched systems with delays has become quite challenging. The present work, highlights the state of art review of switched systems and underlying methodologies to ensure stabilization of such system with individual systems having stable or unstable dynamics. Further, current status and future directions of possible scope and open challenges in this area are also highlighted for completeness.