Robust adaptive-sliding mode tracking of state delayed nonlinear plants with actuator failures

In this paper, we develop two sliding mode-model reference adaptive control (MRAC) schemes for a class of delayed nonlinear dynamic systems under actuator failure that are robust with respect to actuator failures, to an unknown plant delay, to a nonlinear perturbation, and to an external disturbance with unknown bounds. Appropriate Lyapunov-Krasovskii-type functionals with 'virtual' adaptation gains are introduced to design the adaptation algorithms, and to prove stability. Two different controllers are designed: one with discontinuous and another with continuous control actions, respectively. Copyright (C) 2011 John Wiley & Sons, Ltd.