Study For The Network Control Systems Based On Robust H_∞ Control

The Networked Control Systems has the content of this thesis for its superiority as the development of the control system scale. Networked Control System is a new task of control theory in the 1990s, and Networked control systems are feedback control systems here in the control loops closed through the real-time network.The advantages of NCSs are reduced system wiring, ease of maintenance and diagnosis, and increased system agility. However, the insertion of the communication network in the feedback control loop, some new issue such an networked induced time-delay, network packets dropping and network scheduling appear, which all make the analysis and design of an NCS complex. In this thesis we studied stabilization of NCSs when induced time-delay and network packets dropping are considered.1. The problem of robust guaranteed cost controller design for NCS with network-induced delay less than or equals to one sampling period is studied. For linear time-invariant normal controlled plant, the dynamic output feedback NCS is modeled as a discrete time-variant system with uncertainty. Then basing on the Lyapunov approach and linear matrix inequality description, we study the problems of modeling, performance guaranteed optimal control, Give the method to design the performance guaranteed optimal control law for dynamic output feedback NCS.2. The problem of robust H∞control for a class of networked control systems with short transmission delay and limited external disturbance is investigated. There are two parts. (1) In practical control systems, the state of NCS can't always be measured. So we derive the sufficient condition and robust H∞controller design method of asymptotic stability of dynamical output feedback NCS. (2) The state feedback NCS with control input constraints and uncertain delay less than or equals to one sampling period is modeled as a linear time-variant discrete system. Basing on the model built, we development the condition of robust stability and the design method of robust H∞control law for the system.3. The non-fragile H∞control problem is studied for a class of networked control system with time-varying long delays and limited external disturbance. By introducing the equivalent descriptor form of the system and choosing appropriate Lyapunov function, LMI-based sufficient condition for stability of the resulting closed loop system is derived, and the design method of non-fragile H∞control law is also presented.4. For a class of linear time-invariant normal controlled plant with network-induced delay and date packet dropout, the problem of modeling, exponential stability and controller design for NCS. For the given date packet dropout rate, the networked control systems can be modeled as an asynchronous dynamical system constrained by two configuration event rates. Based on the theory of asynchronous dynamical system, the sufficient condition of exponential stability for NCS is derived. Meanwhile, the dynamical output feedback controller can be solved by a...