Time delay dependent optimal control of networked control system

The paper studies the optimal control of networked control systems (NCS) with sensor-to-controller(S/C) and controller-to-actuator(C/A) time delays. The delays are bigger than one sample and stochastic. By using of buffers, the original problem is transformed into linear system with constant delay in control, and the packet disordering due to long delay can be solved by sequencing process in buffers. Maximum principle is used to solve the optimal control problem of NCS with time delay. Because all the arrived packets are saved in buffers, the optimal control can be physically realized by state prediction method. The simulation analyses the effect of m^sc and m^ca that are upper bound of S/C delay and C/A delay. Two different cases are considered. Simulation results illustrate the effectiveness of the controller.