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Network control system is a real-time network and constitute a closed loop through the special distributed feedback control system. Wherein the controller , sensors , drives, through a shared network to exchange information. Network control system integration of computer technology, communication technology and control theory, is an emerging technology and modern industrial production is becoming the main development direction . It has information resource sharing, reduce system cost , flexible, easy to maintain , but also generate network transmission time delay , packet loss and other issues. This not only gives the analysis of networked control systems makes it difficult , and so many of the traditional control theory can not be directly applied to the network control system design. In this paper, a time delay and packet loss network control system carried out relevant research , the main work is as follows: First, we discuss the time- delay and packet loss network control system modeling . In considering system disturbances on the basis of , respectively, with a short delay and long delay of networked control systems modeling , network control system gives the delay discrete time model . With packet loss on the network control system , sub- state feedback and output feedback both cases the system is given a discrete -time model . Secondly, the design of real-time filtering based on wavelet PID controller . Wavelet filtering algorithm for real-time research , built on the basis of wavelet filters , and combined with the PID controller is applied to the control system. In specific instances , based on the discussion of the controller parameters , wavelet function , decomposition depth, the sliding window size, window size and the compensation threshold selection rules based on the choice . Finally, the study of the network control system compensation control . For network-induced delay and packet loss problem of uncertainty , using real-time queuing protocol network-induced delay is limited to a sampling period , and were using three compensation strategies (PD, PD2 and PD3) for lost packets compensation . Combined with an improved wavelet filter wavelet filter and two filters are applied to noise interference with network control systems.
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