Observer-based Robust Control For Neutral Systems With Time Delay

The neutral systems with time-delay is a class of time-delay systems broader than others, which has important applications in population ecology, electric current in transmission problem, heat exchangers, the circuit network system, etc. Time delays and uncertainty are important factors which affect the performance of neutral systems. Therefore, the research for uncertain neutral systems with time-delays has important theoretical and practical significance.This dissertation studies the problem of observer-based robust control for uncertain neutral type descriptor system with time-delays by constructing appropriate Lyapunov-K-rasovskii functional, combining with integral inequality, singular value matrix theory and linear matrix inequalities (LMI). The main works are as follows:(1) The problems of observer-based H∞control, non-fragile H∞control and non-fragile control for uncertain neutral type descriptor systems with time-delays are considered. The observer-based controller is designed which can guarantee the system is stable and satisfies the H∞performance.(2) The problem of the observer-based non-fragile control for a class of uncertain neutral systems is investigated. By constructing a new Lyapunov-Krasovskii functional, using integral inequality and the theory of singular value matrix, the delay-dependent stability criterion is given and an observer-based non-fragile controller is designed. Finally, the problem of the observer-based H∞control is obtained.(3) The mechanical system model is transformed into state equation. The problem of delay-dependent H∞control for mechanical system is investigated by the neutral system theory. By constructing a new observer system, combining with the Lyapunov-K-rasovskii stability theory and model conversion method, the delay-dependent robust H∞control criterion is given and an observer-based H∞controller is designed.(4) The problem of robust absolute stability for nonlinear neutral systems with saturating actuators and parameter uncertainties is investigated. Based on Lyapunov-Krasovskii stability theory, the delay-dependent stability criterion for closed-loop system is given and the design method of observer-based controller is obtained.