Adaptive Sliding Mode Tracking of Nonlinear Plants With Multiple Unknown Time-Varying State Delays

In this paper, we develop a sliding mode model reference adaptive control (MRAC) scheme for a class of nonlinear dynamic systems with multiple time-varying state delays which is robust with respect to unknown plant delays, to a nonlinear perturbation, and to an external disturbance with unknown bounds. An appropriate Lyapunov-Krasovskii type functional is introduced to design the adaptation algorithms, and to prove stability.