Research On Event-Triggered Communication And Robust Control Of Uncertain Networked Control System

With the development of fully digital communications,the open Internet network and the communication technology,more and more network technologies are applied to the control system,the networked control system(NCS)has become a research emphasis of scholars in the field of automation at present.The communication network link is embedded in NCS based on the traditional control system,its function is to pack the control information and feedback information of every element and this feature makes NCS have many advantages,such as low cost,less cabling,high reliability and information resource sharing and so on.However,all kinds of disadvantages NCS itself carried form the block for the analysis and design of NCS which cause the problem of the network induced delay,the packet dropout and reordering,the quantization error and the different driving mode of the node.The original performance of the control circuit will be inevitably affected by these questions,which also make the uncertainty of the system increased and even lead to system instability.In addition,as a kind of complicated sampling system,NCS is influenced,to a certain degree,by the working environment and random interference in the process of running,so there are a large amount of different types of uncertainties which will cause damage to the stability of the system.Therefore,in view of the NCS with uncertainty,in order to take into account the network quality and control performance,it is the current important task that the event-triggered mechanism is adopted to improve the robust stability analysis and robust synthesis of system.This paper focuses on two classes of uncertain linear NCS,the system modeling,stability analysis and the co-design of event-triggered mechanism and robust control are researched.This mainly includes the following aspects:1.A NCS model with poly-topic uncertainty and time-varying delay is set up.Considering time-varying property of network delay of the NCS,the time-varying delay is made linearly segmentation,the discrete event trigger condition containing information of time delay is structured,under the state feedback control strategy,a NCS model with poly-topic uncertainty containing both time-varying delay and event triggering parameters is built.2.A NCS model with norm-bounded uncertainties,time-varying delay and data packet dropout is established.Considering NCS with time-varying delay and continuous packet dropout,the pocket dropout is translated into delay and total delay is linearly divided.According to the static output feedback,the event trigger conditions based on output is constructed,and according to the state feedback based on observer,the event trigger conditions based on state is built,so a NCS model with norm-bounded uncertainties,network properties and trigger condition is received.3.Robust ?H control for NCS with poly-topic uncertainty based on discrete event-triggered mechanism is studied.The Lyapunov function related to the parameters is adopted on the basis of the established NCS model with uncertainties,Further,the Jensen inequality and Wirtinger inequality are combined to deal with it.Next,the sufficient and necessary conditions for the asymptotically stable of system and the solution procedure of robust ?H controller related to poly-topic uncertain parameters are obtained via solving the linear matrix inequality(LMI).4.Robust analysis of NCS with norm-bounded uncertainties based on discrete event-triggered mechanism is done.One new Lyapunov function is constructed on the basis of the established NCS model of the output feedback and observer with uncertainties which includes the delay of two channels and the number of continuous packet dropout.Next,the linear matrix inequality is deduced through Jensen inequality,Wirtinger inequality and some related lemmas.Finally,under the controller and observer gain,the delay-dependent stability criterion is gained.