Global adaptive output feedback stabilization for nonlinear time-delay systems with unknown measurement sensitivity

In this article, a global output feedback stabilization scheme is proposed for a class of time-delay uncertain nonlinear systems with unknown measurement sensitivity. A new high gain observer is designed with which the sensitivity function can be tackled by only one dynamic gain and the coupled linear-like controller is fairly simple. By introducing some transformations of the state estimation errors and observer states, and appropriately choosing Lyapunov–Krasovskii functionals, it is proved that the proposed controller can globally stabilize the system.