Study Of Networked Control Systems Based On Estimator

Networked Control System (NCS) constitutes a closed loop feedback control system through networks. It combines theories of computer science, telecommunications and control systems. Meanwhile it directs the modern industry and becomes one of the updating technologies. There are many advantages of this technology. For instance, it is cheap, reliable, flexible and easy to be installed. Also, resources can be shared in the system. This thesis will focus on the research and analysis of the delay problem of NCS. The main tasks of this thesis are shown in the following.Based on the research of constructions and basic problems of the control system, network delay system will be modeled. Then it will provide the model of multi-object and multi-controller delay system. All the tasks will concentrate on the delay problems.The thesis will analyze and state the causes, compositions and features of the delay problem. According to these, it will study on control methods of NCS. It will propose a combined model which is based on the bilateral network control system. Then it will analyze the effectiveness of the model. The combined model will be applied to the design of controller with function of network delay compensation. This application will use the data of real network delay. The experimental will reveal that the dynamic performance will be improved significantly compared with controllers without delay compensation. After that, it will propose some control methods using state-feedback estimated compensation. Also, the effectiveness of these methods will be proved. Most importantly, the thesis will introduce Smith estimate method to the network control system. Some methods will be provided in order to improve this method. The simulation of motor model will show that this method can offer better control.Finally, the thesis will use TrueTime, which is the toolbox of Matlab, to simulate the network control system. It will prove the function of this tool by motor model and the method of Smith estimate.