Global adaptive output feedback control for a class of uncertain nonlinear time-delay systems

In this paper, the output feedback control problem is considered for a class of uncertain nonlinear time-delay systems. The system nonlinearities satisfy linear growth condition on unmeasured states multiplied by unknown growth rate and output polynomial function. With appropriate Lyapunov-Krasovskii functional, a memoryless adaptive output feedback controller is developed to guarantee global stability of the nonlinear time-delay systems. The precise knowledge of the time-delay is not required to be known a priori. Furthermore, only one dynamic gain is designed, which makes the controller easier to implement. A numerical example is used to illustrate the effectiveness of the proposed method.