Research And Design Of Network Control System With Random Time-Delay Compensation

Networked control systems are distributed feedback control systems,which allows for a reduction of wiring and a lower installation cost,owing to greater agility in diagnosis and maintenance procedures.But due to the existence of network time delay,the control commands and transmit information of the network control system often cannot promptly executed,deteriorating the system performance,which may even influence the stability of the system.In order to solve the problem and improve the stability of the network control system,this thesis analyzed the characteristics of the time delay in network,then time delay compensation strategy is poposed.This paper mainly studies the following aspects:Firstly,with the mechanism model of the system,which refers to system correlation and factors such as network topology,the model of networked control systems with random coupling delay is built.This thesis analyses the coupling of random time delay in network control system of the mixer control system based on the network model.Secondly,according to the random uncertain time delay of the networked control system,a large number of measured delay samples are analyzed and processed,then the adaptive AR predictive model is proposed.On the basis of consideration on prediction accuracy and real-time property in the algorithm,the model ascertains its order automactilly and uses the least mean square algorithm using the new time delay in order to adjust the weighting factor online.The simulation results show that the delay estimation algorithm using self-tuning AR model has much better prediction effect on delay.Finally,aiming at many problems existed in the control circuit coupling delay,on the basis of random time-delay network control system modeling,the stability of the system is analyzed.This thesis proposed a control algorithm based on adaptive time delay compensation.Simulation results show that the method enhances compensation effect of the network delay.Besides,the adaptive rules is simple,flexible and practical in form.