Robust Control For A Class Of Discrete-time Systems With State Saturation Nonlinearity Constrains

Saturation phenomenon generally,exists in biological,engineering and social economy practical systems,Saturation constraint is an inevitable problem in com-puter control,digital signal processing and other fields.Therefore,it is very neces-sary to analyze the stability of the control systems with saturation constraint from theoretical and practical aspects.In this thesis,attention is focused on the problem of robust control for the discrete-time systems subject to saturation nonlinearities.Firstly,we summarize the development and research status of robust control for discrete-time systems,and give the basic knowledge and theory.For discrete-time systems with saturated nonlinear constraints,we present sufficient conditions for asymptotic stability of the system and the design method of the controller based on Lyapunov stability theory and Linear Matrix Inequality(LMI)method.Specific research work is organized as follows:For a class of discrete-time systems with saturation nonlinearity,the problem of designing a guaranteed cost state feedback controller is considered in this paper.A sufficient condition for the existence of state feedback guaranteed cost controller is derived by the means of Lyapunov stability theory and linear matrix inequalities.The problem of the guaranteed cost control for a class of uncertain discrete-time systems with both state and control input delays is discussed.The design problem of the optimal guaranteed cost controller is obtained by solving a convex optimization problem.This paper considers the problem of robust_?control for a class of discrete-time systems with perturbation and saturation nonlinearities.the design method of the optimal_?controller is obtained through the analysis of-sub-optimal_?performance of the system.