A Class Of Delay Switched Systems Analysis And Control

Switched delay systems have attracted the interest of several scientists more and more due to their many applications in engineering and great significance of theoretical study.It is considered that in actual systems there inevitably exists some nonlinearity which always satisfies Lipschitz condition,therefore,the problem of analysis and synthesis for a class of Lipschitz nonlinear switched delay systems is investigated in the dissertation.The main contributions are as follows.The stability property,H_∞performance and L_∞performance of nonlinear switched delay systems are studied.The problem of exponential stability of nonlinear switched delay systems is discussed,in which delays are constants.Conditions in the form of linear matrix inequalities(LMIs) are presented to guarantee exponential stability of such systems.The results can be reduced as the exponential stability conditions of linear switched delay systems. Based on the stability condition and LMI technology,the H_∞performance and L_∞performance of systems are analyzed and the solution methods of corresponding performance bound are proposed,respectively.The problems of robust H_∞reliable control and robust L_∞reliable control for nonlinear switched delay systems are addressed.The outputs of the faulty actuators are regarded as disturbance inputs,robust H_∞reliable control and robust L_∞reliable control are discussed for uncertain nonlinear switched delay systems with actuator failures where uncertain parameters are assumed to be time-varying but norm bounded,such that within the rage of actuator tolerance the finite energy distribute or persistent bounded external disturbance with infinite-energy can be attenuated effectively.It is considered that there exists mismatched period between the switching of the controller and the system,robust control for switched delay nonlinear systems under asynchronous switching is investigated using dwell time method,in which delays are constants.When there exists asynchronous switching between the controller and the system, the stabilized controller is designed,and the low bound of dwell time is derived to guarantee the exponential stability of systems.Moreover,based on average dwell time method,the controller and switching signal are designed for nonlinear time-varying switched delay systems and nonlinear discrete-time switched delay systems are studied,respectively.The average dwell time of systems and the ratio of matched period and mismatched period between the controller and the system are derived to guarantee the exponential stability of systems by solving a set of inequalities and equations.The concept of non-fragile observer is introduced.A non-fragile observer design methodology for a class of continuous-time nonlinear switched delay systems is proposed based on dwell time method.Moreover,average dwell time method is used to design non-fragile observer for discrete-time nonlinear switched delay systems.For a class of systems satisfying the prescribed dwell time or average dwell time,the continuous or discrete gain matrices of non-fragile observers are obtained by solving a set of linear matrix inequalities,respectively.