Adaptive actuator failure and disturbance compensation scheme for MIMO feedback linearizable systems

摘要

A feedback linearization based adaptive control scheme is developed for multivariable nonlinear systems with redundant actuators subject to uncertain failures and unknown unmatched input disturbances. Such an adaptive controller contains a direct adaptive actuator failure compensator to compensate the uncertain actuator failure, a nonlinear feedback to linearize the nonlinear dynamics, and a linear feedback to stabilize the linearized system. Based on the feedback linearization design, a nominal output rejection scheme is first developed, for which the relative degree characterisation of the control and disturbance system models from multivariable nonlinear systems is specified as a key design condition for this disturbance rejection design. With direct control signal adaptation, the adaptive failure compensation design ensures closed-loop stability and asymptotic output tracking in the presence of actuator failure uncertainties. Simulation results are presented to verify the desired system performance with adaptive actuator failure and disturbance compensation.