Study On Simulation Of Wireless Network Control System

With the development of communication technology, the traditional way which is point-to-point control way already can not meet the demand of modern industrial control. Gradually control system is networked. And wireless network control system, which has advantage of high flexibility, has become the focus in the control theory. For the research of wireless network control system, because of the network protocol, the controller and so on, only from the perspective of theory research is very difficult.But if take experimental method, the high cost is a problem again. So using the simulation tool for modeling and simulation is a feasible and useful method. But so far, the simulation of the wireless network control system is relatively little and comprehensive enough.Generally speaking, the analysis and design research of the network control system are often carried out from two angles. One which is based on communication theory is optimizing the network itself, to reduce the network extending to packet loss and delay. The more optimal controller is designed is another one which is based on the control theory, to reduce the influence of network extending to packet loss and delay.From the first Angle wireless network control system is studied in the third chapter of this paper. The WINCS simulation system is established based on the TrueTime simulation toolbox. By changing the properties of the network itself, the effects of the time-delay, interference, sampling period, the data transmission rate, scheduling strategy and the distance between the nodes to the performance of wireless network control system are studied. The simulation results show that the network time delay is greater, the control performance of WiNCS is poorer;the interference is greater, the control performance of system is becoming worse; sampling period is too big or too small can make the system control performance poor; the transfer rate of data is greater,the control performance of the system is better in theory; the influence of different scheduling policies to the control performance of wireless network is different; with increasing the distance between the nodes, the control performance of system is worse and worse.From the second Angle wireless network control system is studied in the forth chapter of this paper. According to the problem of time delay, the method is put forward which is fuzzy immune combined with an improved Smith compensating. The fuzzy immune PID controller and the structure of improved Smith forecast compensation are designed. Simulation results show that the method is effective which is used to control the wireless network control system.