Research On Robust Control For Networked Control Systems

With the development and widely applications of network technology, the structure of control system has changed gradually: the traditional structure transforms to networked control structure. For the advantages such as public info-resource, less links, more extendable, more maintainable, high-efficient, high-reliability and flexibility, the networked control structure will prevail in the future. However, there're also faults in this structure, such as time-delay induced by network, data packet dropout, mistake sequence of data, error code and so on. The traditional control theories and means couldn't be directly applied to networked control systems because of these faults. In order to develop advanced control strategy for networked control systems, we should present novel concept and mean for networked control systems analysis and controller design.This paper analyzes the networked control system with both time-delay and data packet dropout based on Lyapunov stability theory, descriptor transform, matrix cross-term bounding and Linear Matrix Inequality (LMI). The main work and research are as follows:1. Analyze the stability of system and design controller for continual-time networked control systems, and refer to the system with uncertainty. The sufficient conditions which are subject to asymptotic stability are derived, and the design approaches of the controller which are less conservative are given in the form of LMI. Then the validity of these approaches is proved by numerical demonstrations.2. Analyze the stability of system and design controller for discrete-time networked control systems, and refer to the system with uncertainty. The sufficient conditions which are subject to asymptotic stability are derived, and the design approaches of the controller are given in the form of LMI. Then the validity of these approaches is proved by numerical demonstrations.3. Extend these approaches of controller design to robust H_∞control and presentcontroller design manners in the form of LMI for continual-time and discrete-time systems respectively. Then apply the manner of discrete-time system controller design to car inverted pendulum system, and the simulate result prove its validity.Finally, the summarizations of the work in this paper and the potential research directions of networked control systems are pointed out.