Global Stabilization of a Class of Time-Delay Nonlinear Systems with Unknown Control Directions by Nonsmooth Feedback^⁎

Abstract

© 2018 This paper addresses the problem of global stabilization for a class of time-delay systems with inherent nonlinearity and unknown control directions, which may not be controlled by any smooth feedback. The dynamic gain based approach in Zhang, Lin and Lin (2017) and the idea of Nussbaum-gain function Nussbaum (1983) are employed to deal with inherently nonlinear systems with time-delay in the presence of unknown control directions. With the help of appropriate Lyapunov-Krasovskii functionals, we design a non-smooth delay-independent feedback control law that guarantees the global asymptotic convergence of the system state and global boundedness of the resulting closed-loop system.