Robust Control For Discrete Time-delay Systems And Its Application

This paper deals with the problems of robust stability analysis and robust controller design for discrete time-delay systems. Due to the computer widely used in the industry application, the discussion of the problem not only can perfect the theoretical basic of time-delay systems, but also will promote the application of time-delay systems. The delay-dependent stability criteria and robust control are mainly discussed, which are challenging researches in control issue for time delay system. The main work and contribution of this thesis are as follows: Firstly, the delay-dependent robust stability criteria and robust control problem are considered and some new results are developed. Based on the Lyapunov function and sophisticated Lyapunov-Krasovskii functional incorporated with a special constructing difference format, we give some novel results for delay-dependent robust controller design. The new idea of 揷ontrolling delay?is proposed in the design approach. The memoryless state feedback and dynamic output feedback controller design methods are given, respectively. Furthermore, the delay-dependent decentralized stabilization controller design problem is investigated for a class of discrete time-delay uncertain large-scale systems of the similar structure with the nominal system structure. The time delay feedback design is investigated further by using the Lyapunov-Krasovskii functional, and the robustness for time-delay is analyzed. Secondly, we introduce the robust resilient control to time-delay systems. The robust control issue can be well applied in practical application under the consideration of the actual controller parameter perturbation. The direct augment method is presented to the reliable controller design of discrete time-delay systems based on the resilient control design. By using our method, there is an excellent tradeoff between the robustness and the fault tolerance of the time-delay system. Thirdly, the robust passivity stabilization controller design for time delay system is presented. The result extends the existing result of the passivity stability 桰II- of time delay system. Besides, it gives a new method to study the nonlinear discrete time-delay system or nonlinear uncertainty of discrete time-delay systems. Nextly, the robust stabilization controller design problem is illustrated for 2-D discrete system. Based on the linear matrix inequality (LMI) technique, a design frame for the robust stabilization controller with H_inf and guaranteed cost performance of 2-D discrete system are given. Sufficient condition on the existence of proposed robust H_inf and guaranteed cost controller are acquired. Finally, the robust control for time-delay systems is applied to the congestion control of Asynchronous Transfer Model(ATM) network. Now, a suitable flow management is under investigation by combination with traffic predictive model and fuzzy-neural network congestion controller, which can deal with the sophisticated network environment.