Research Of Networked Control System Based On Stochastic Delay Process

With rapid development of the computer network and communication technology, the control system comes into network and intellectualized step by step, and the networked control system has become one of the research hotspots. As the communication network is induced into the control system, new requirements has brought forward for analysis and design methods of the control system: one side, after the communication network is induced into, the additional delay is brought artificially. The uncertain delay results in lots of trouble for modeling and analyzing the control system. So the new methods on analyses of the control system should be studied urgently. On the other side, the contradiction appears between the requirements on real-time of the control system and the limited communication network resource. It is one of the preconditions for application of the networked control system engineering to coordinate and resolve this contradiction.In this paper, the network-induced delay in networked control system is analyzed and studied mainly. There are following research work:(1) The reason to appearance of the network-induced delay and affecting factors are analyzed, and then the models with the constant delay and stochastic variable delay in closed loop are founded respectively; the stochastic delay in networked control system affects the system performance is approved by simulation.(2) Using the method of adding buffer, the stochastic transmission delay can be changed into deterministic delay networked control system; more reasonable method of setting the buffer is given. The optimal state feedback and optimal output feedback controller are derived with the optimal control theory;(3) The optimal control with finite time and optimal control with infinite time of networked control system with the independent distributing transmission delay less than one sampling period in this paper. In solving the optimal control law with finite time, the matrix Riccati differential equation can be changed into the matrix Riccati algebraic equation through discretization;(4) There is little research on the networked control system with Markov delay. So this paper has analyzed the signal transmission time sequence when the controller and actuator are driven by event, then the Markov performance of the network transmission delay is studied, and also the stochastic optimal state feedback controller and stochastic optimal output feedback controller are studied.