Observer-based Control For Time-delay Hamiltonian Systems With Uncertain Parameters

As is known that the full state information of the state vectors are not always be measurable in many real world control systems,therefore,the observer design of nonlinear systems is an important research field of system control theory.In the recent twenty years,a number of studies about nonlinear observers have been researched.As a significant class of nonlinear systems,the observer–based control problems of port–controlled Hamilton system has received great attention.Since it is inevitable that the system will be affected by time delays,stochastic disturbances and so on,the observer–based control problems of nonlinear Hamilton systems is of great meaningful.Firstly,this paper is concerned with the problem of stabilization and 2–disturbance attenuation for a class of uncertain Hamiltonian systems in the presence of unavoidable input and output time delays and external disturbances as may occur in controller implementation.The dissipative structural properties of the uncertain delayed Hamiltonian systems are fully considered,and sufficient criteria are obtained by application of Lyapunov–Razumikhin functional theorem and Luenberger–type observer to guarantee the asymptotical stability of the closed–loop systems for any given arbitrarily large yet bounded delays.An observer–based controller with an assistant reference input is designed corresponding to the external disturbances and time delay pattern involved in the systems.It is shown that the closed–loop systems under the feedback control law can guarantee the –dissipative inequalities be satisfied.The efficiency of the results is demonstrated by the example of observer–based control of a power system.Besides,on the basis of the existing research results,for a class of uncertain stochastic Hamiltonian systems with state and input delays,a robust adaptive observer–based controller was derived by using linear matrix inequality technique and the Wirtinger's inequality and constructing a suitable Lyapunov function as well as a differential state observer.In addition,for the system without stochastic disturbances,we also obtained the observer–based adaptive stabilization conditions.The observer proposed in this paper discards the stochastic disturbances,which makes the observer more stability and easy to implement.