Research On The Model And Control Method Of Control System Based On Network

With the development and cross-penetration of control of science, computer network and communication technology, networked control (NCS) came into being and is becoming an international academic research hot spots. The primary advantages of NCS are sharing of information resources, flexibility, good self-diagnosis and maintaining good performance. However, because of inserting the networked into traditional control system and the limits of the network bend, it is inevitable for the existence of the information transmission delay, collision, timing disorder, and even data packet loss, etc, which are the main factors to degrade the performance of control systems.The Modeling and Control of the Networked Control Systems are studied for Linear Time Invariant System in this dissertation.Firstly, the models of the NCS with short delay are given. Sensors used for the time-driven, controllers and actuators used for event-driven, uncertain delay NCS is equivalent to a class of uncertain discrete linear system. Based on the Lyapunov function and the Linear Matrix inequalities (LMI), the sufficient condition for the NCS which is subject to the asymptotic stability and H_∞performance are derived. The design approach of the controller is given.Secondly, the models of the long-delay NCS are presented. Supposing the close loop system without network is asymptotic stable, the sufficient condition for the stability of the close loop system including network is derived based on the Lyapunov function and LMI. For the NCS with only control delay, assuming the sensor and the actuator node are synchronous, using receiver cache technology, time-varying delay will be converted to a fixed delay, the NCS with only control delay will be converted to a system of linear delay discrete systems. The sufficient condition for the NCS which is subject to the asymptotic stability is derived and the optimal controller is designed.