Resilient delay-dependent adaptive control of uncertain time-delay systems

In this article, resilient delay-dependent adaptive control algorithms are developed for closed-loop stabilization of a class of uncertain time-delay systems with time-varying state delay, nonlinear dynamical perturbation, and controller gain perturbation. The norm of the nonlinear perturbation is assumed to be bounded by a weighted norm of the state, and the norm of the uncertainty of the state feedback gain is assumed to be bounded by a positive constant. Two main problems are investigated. In the first problem, an adaptive control scheme is developed to guarantee asymptotic stabilization of the closed-loop system when the value of the upper bound of the norm of the state feedback gain perturbation is known. In the second problem, asymptotically stabilizing adaptive controller is derived when the value of the upper bound of the norm of the state feedback gain perturbation is assumed to be unknown. A numerical simulation example, that illustrates the two design approaches, is presented.