Research On Robust H-infinity Control For Uncertain Time-delay Systems

This paper studies the robust H∞control problems of several uncertain time-delaysystems. First, we introduce the general situation and current research of therobust H∞control of uncertain time-delay systems. And then to improved delay-dependentrobust control for uncertain time-delay systems, to study the problem of H∞observer designfor the linear uncertain systems with time-delay and the stability conditions and H∞controller design for the discrete systems with time-delay, respectively. Specific results areas follows:(1) This paper present a new stabilization criterion for asymptotic stability of thetime-delay systems with norm-bounded time-varying uncertainties. The delay-dependentstability criteria is derived in terms of matrix inequalities by establishing the Lyapunovfunctional which have free weighting matrices. A numerical example shows theeffectiveness of the proposed method.(2) This paper deals with the problem of H∞observer design for a class of uncertainlinear systems with delay state and parameter uncertainties. Designing a linear stateobserver such that, for all admissible parameter uncertainties, the observation processremains robustly stable and the transfer function from exogenous disturbances to error stateoutputs meets the prespecified H∞norm upper bound constraint, independently of the timedelay. A numerical example demonstrates the validity and applicability of the presentapproach.(3) The robust H∞problem of a class of uncertain discrete systems with time-delayare studied. This paper discusses the discrete systems with state delay and input delay, to design a state feedback controller such that, the closed loop system is stable, the transferfunction meets the H∞norm upper bound constraint.