Adaptive backstepping actuator failure compensation for a class of nonlinear systems under relaxed conditions

An adaptive backstepping output-feedback compensation control scheme is proposed for a class of nonlinear systems with actuator failures. The assumption on the sign of high frequency gain is removed. To achieve this objective, a new linearly parameterized model is established. The Nussbaum gain approach is utilized to cope with the completely unknown high frequency gains. The boundedness of all the closed-loop signals and asymptotic output tracking are guaranteed. The benefits of the proposed design method are demonstrated by a numerical example and its simulation results.