Robust Control For Singular Networked Control Systems With Short Time-Varying Delay

In the past twenty years,with the rapid innovation of automation,network,computer,and other science and technology,the research on network control technology has attracted the attention of many scholars.Network control systems(NCSs)have the characteristics of light weight,maintenance friendly,easy to upgrade,less wiring and so on.Therefore,NCSs are superior to traditional control systems in system structure and performance.Because the bandwidth of the network is physically limited in NCSs.The sending right of packet is not fixed,so it needs to get the sending right of each node in the network through competition.Therefore,the time delay phenomenon always occurs in the process of packet transmission.The influence of network-induced delay on NCSs has always been a hot topic for the research of many scholars.Compared with general systems,singular systems have more extensive forms.Since the 1970s,many scholars have begun to explore and investigate singular systems.Therefore,the research of singular NCSs is very necessary and meaningful.In this thesis,the robust control for singular NCSs is discussed.The network-induced delay is assumed to be time-varying and less than one sampling period.In the modeling process of the system,the effect of network-induced delay on system conservativeness is fully considered.The results of the existing literature are improved by using the nominal point method.Using the Linear matrix inequality(LMI)technique.Firstly,the stability of singular NCSs is analyzed.Secondly,the guaranteed performance control of singular NCSs under exponential stability is discussed.Finally,the optimal H_? control of singular NCSs under exponential stability is studied.The main contents and contributions of this thesis are as follows.(1)The stability of singular NCSs is analyzed,and the design method of the state feedback controller is given.By using the idea of optimization,the supremum of the Euclidean norm of the exponential uncertainty and its corresponding nominal point are obtained.Thus,it effectively solves the problems that the existing methods do not consider the relationship between the network-induced delay and the system conservativeness and the application scope is limited.(2)Based on the nominal point method,the guaranteed cost control of singular NCSs under exponential stability is studied.In the LMI framework,the existence condition and the design method of the state feedback controller are given to ensure that the system is exponential stable and the quadratic performance index is not greater than a given upper performance bound.Because the conservativeness of the system is fully considered,the quadratic performance index of the system is better optimized.(3)Based on the nominal point method,the optimal exponential H_?control problem of singular NCSs with short time-varying delay is studied.The existing conditions and the design methods of general and optimal exponential state H_?feedback controllers are given.It effectively solves the problem that the existing method increases the network-induced delay,which results in the system performance degradation and the application scope is limited.