Stability Analysis Of Networked Control Systems With Communication Constraints

Since the 19 th century,after the rapid development of computer technology and communication network,they have been more and more widely used in our daily production and life.The traditional control systems have been unable to meet the needs of The Times.Therefore,the networked control systems,which combines the traditional control systems with the network has gradually attracted extensive attention of experts and researchers at home and abroad.After that,many achievements have been made in the research.The control of intelligent robot,the birth of unmanned boat and the operation of remote equipment,they all have the application of networked control systems.Networked control systems(NCSs)is a kind of control system which connects all parts of the traditional control systems and carries out information interaction by using communication network.Compared with the traditional control systems,the networked control systems have no need to worry about the limitation and influence caused by the distance between the components.Networked control systems have many advantages over traditional control systems in price,maintenance and public safety.However,as the information is transmitted through the communication network,networked control system naturally produces a number of problems in the communication process,such as network-induced delay,channel noise,bandwidth limit,data packet loss,etc.Those above will certain impact on the performance of the system.In this paper,the stability of networked control systems is studied under the influence of communication parameters.By using the techniques of mutual quality decomposition,frequency domain analysis and spectrum decomposition,etc.In addition to the theory of norm and the theory of Youla parameterization.The stability condition of networked control systems is obtained by solving the signal-to-noise ratio.In addition,the performance limit of networked control system under the premise of stability is discussed.The main contents of the study are as follows:The influence of communication constraints on the stability of a single input single output networked time-delay systems is considered.According to the finnal results,we can know that the stability problem of networked time-delay system will be affected by the properties of the given object.In addition,the constraints that existing in the communication channel will also affect the stability of the system.For networked control systems,the system stability problem that influenced by various parameter,including time delay,noise,packet dropout and encoder-decoder are studied.The stability of NCS is studied by means of frequency domain analysis and spectral decomposition.From the research results,we can get the conclusion that the minimum value of the stability of the networked control systems is affected by the unstable poles,non-minimum phase zero and other factors of a given object.In addition,the existing constraints in the communication network also affect the stability of the control system to a certain extent.For networked control systems,under the premise of stability,the tracking performance limitation problem with the common constraint of time delay and two-way channel noise is discussed.Here,we consider that channel noise exists in both the forward channel and the feedback channel.In addition,in order to consider the complexity of the situation,there is a time delay in the forward channel.The results show that the performance limitation of networked control systems is affected by the attributes of the given objects and their directions.On the other hand,the constraint condition of communication channel also affects its performance limitation to a certain extent.The above research results will play a certain role in the future study of networked control systems.