Delay-dependent H_∞ Control For Continuous Linear Systems With Time-varying Delay

This dissertation mainly deals with the problem of delay-dependent H_∞ control for continuous systems with time-varying delay. By introducing some free matrices and taking the Newton-Leibniz formula into account, some improved results, which are less conservative than the existing ones, are obtained.In chapter 1, the research background of time-delay systems and H_∞ control of such systems are introduced. Furthermore, the research problem, organization and notations of this dissertation are also given.In chapter 2, an improved criterion of delay-dependent stability with H_∞ performance for such systems is presented. An existent criterion and some corresponding design methods of delay-dependent H_∞ controller for such systems via state-feedback are proposed. Furthermore, the corresponding results for the delay-dependent robust H_∞ control problems for continuous time-delay uncertain systems are also given. Finally, three numerical examples are given to illustrate the efficiency and superiority of the proposed method by comparing with the existing results.In chapter 3, the problems of delay-dependent sampled-data H_∞ control for continuous systems with time-varying delay are studied, and the existent criterion and some design methods of delay-dependent sampled-data H_∞ controller for such systems are proposed.Finally, in chapter 4, the main results of this dissertation are concluded, and the prospect of the research work is also discussed.