Research On Networked Control System With Time Delay And Data Packet Dropout

With the rapid development of control technology, computer technology and network technology, the traditional point-to-point control system has not kept up with the complicated modern control requirements. And the traditional control system is being gradually replaced by Networked Control System (NCS). NCS is a loop-locked feedback control system, which are linked together with sensors, controllers and actuators by communication network. Compared with the traditional control system, the advantages of NCS are geographical space unconstrained, simple wiring, convenient maintenance and low cost, etc. However, some new problems also occurred. For example, the data collision, crash and congestion always appeared in large data transfer process, because of the limited bandwidth of the network. Then, the issues such as network-induced delay, data packets dropout and timing disorder are inevitable, these problems will reduce the performance of the system, even make the system become unstable. Thus, the network-induced delay and data packets dropout is very necessary.In the present study, we summarized the development and research status of the NCS, and discussed some essential issues. The cause and character of the network-induced delay and data packets dropout were also analyzed.In the present study, the system is modeled as an Asynchronous Dynamical System on the single packet transmission in NCS, when the short time delay and data packet dropout exist simultaneously, but without timing disordered. We need to construct the NCS into the Lyapunov function, get sufficient conditions of the stability of the system and the parameters of state feedback controller, output feedback controller and the state observer by Linear Matrix Inequality.For the NCS with uncertain delay and data packets dropout, this paper studied the problem of robust fault-tolerant control when actuators are faulty in the Networked Control System. Based on Asynchronous Dynamical System theory, Lyapunov Stability theory and Linear Matrix Inequality, we were given a sufficient condition for asymptotic stability of the system. Meanwhile, the robust fault-tolerant controller is designed to give corresponding simulation results, combined with numerical examples which can show the reasonable and the exactness of the proposed methods.