Event-Triggered Controller Design And Synthesis Analysis For Networked Control System

Compared with the structure of traditional point-to-point control,the networked control system has the advantages of low cost,less wiring,simple system maintenance and high agility,which has been widely used in power systems,environmental monitoring,telemedicine,aerospace and other engineering fields.However,in a networked control system,the constraint on channel bandwidth of the communication network will increase the probability of network conflicts,such as excessive network nodes,ultra frequent information transmission,or extremely large data transmission rate.Furthermore,some problems such as network-induced time lag,data packet loss,network congestion,information quantization,and limited node transmission will inevitably occur in the process of control information transmission.On another hand,nonlinear phenomena are unavoidable and cannot be completely eliminated in networked control systems;in addition,the bandwidth limitation of the network will cause changes in the type and intensity of the nonlinearities.Thus,these problems will cause the performance of the control system to degrade,and even make the system unstable and crash.At present,the research on related issues is still not enough,so it is of vital significance to conduct relevant research on networked systems in a restricted communication environment.In view of the inadequacy of existing research on the networked control systems,this dissertation will uses T-S fuzzy modeling method to solve the nonlinear problems in the networked control systems.At the same time,by introducing the event-triggered mechanism into the networked control to solve the problem of limited network bandwidth.Finally,the network system event-triggered control strategy is applied to a satellite attitude control system.The research content of this thesis is as follows:(1)For the nonlinear problems in the networked systems,T-S fuzzy modeling is performed on the system,and the networked control problems with actuator delays are analyzed.Then,by establishing Lyapunov functional and time-delay system analysis method,it is obtained that the control system satisfies certain performance under stability conditions.Finally,a fuzzy output feedback controller that meets the expectation conditions is designed.(2)In view of the outstanding advantages of the event-triggered strategy,the design method of an event-triggered controller for a continuous-time networked system is studied.The system model with time delay is obtained through the time-delay system analysis method,combined with the original system model,and then the Lyapunov stability analysis method is used to prove the feasibility of the designed event-triggered controller.Beyond that,the existence conditions of the proposed event-triggered controller are also provided.(3)For the satellite attitude control system,the aircraft attitude control model is established,considering signal quantization and external disturbance.Continually,based on the event-triggered strategy and state feedback control method,an event-triggered controller is designed and its effectiveness is verified.