Optimal Control Of Multi-Rate Networked Conrrol Systems

Feedback control systems wherein the control loops are closed through a real-timenetwork and the sampling periods of sensor, controller and actuator are not the same arecalled multi-rate networked control systems (Multi-rate NCSs). The sampling with multi-rateis natural selection of the networked control systems, which can give full play to theadvantages better that based on the network to control system. So to study the problems ofmodeling and optimal control of multi-rate networked control systems have importanttheoretical significance and practical application value.In this paper, the concept of so-called multi-rate networked control systems is a newconcept. Networked control systems with single-rate mode means the sampling period ofsensor, controller and actuator are the same. Networked control systems with multi-rate modemean the sampling periods of sensor, controller and actuator are not the same.Then we are concerned with the stabilization control of deterministic NCS. Based onLMI and Lyapunov functions, the necessary conditions for asymptotical stability fordeterministic NCS are given. The designing method of state feedback controller fordeterministic networked control systems is proposed in this paper.After for the multi-rate networked control systems with short time delay, and the controlmode and actuator mode are all clock driving, modeling the controlled plant to a deterministicswitching system model, and give the optimal control law which meets the quadraticperformance indexes. Using Matlab simulation, we can have the optimal controller,simulation and example results prove the design of linear quadratic optimal regulator inδ operator have superior dynamic response characteristics.The last, according to the stochastic multi-rate NCSs with long time delay, modeling astochastic discrete model. An optimal control method inδ operator domain is designed byusing a dynamic programming approach. The derived optimal LQG controller can be used asa delay-compensator for multi-rate NCSs with long time delays. Using Matlab simulation, wecan have the optimal controller, simulation and example results prove the design of linearquadratic optimal regulator inδ operator have superior dynamic response characteristics.