Dynamic partial state feedback control of cascade systems with time-delay

Abstract

This paper investigates the problem of global stabilization by partial state feedback for a class of cascade nonlinear systems with time-delay. Under suitable ISS conditions imposed on zero-dynamics, a delay-free, dynamic partial state feedback compensator is presented for achieving global state regulation. The controller is constructed by employing a dynamic gain based design method, together with the ideas of changing supply rates and adding an integrator. With appropriate choices of Lyapunov–Krasovskii functionals, it is shown that all the states of the time-delay cascade system can be regulated to the origin while maintaining boundedness of the closed-loop system. Two examples are given to illustrate the effectiveness of the proposed dynamic partial state feedback control scheme.