An adaptive actuator failure compensation controller using output feedback

An adaptive control scheme using output feedback for output tracking is developed for systems with unknown actuator failures that some unknown inputs are stuck at some unknown fixed values at unknown time instants. An effective controller structure is proposed which achieves desired plant-model output matching when implemented with matching parameters and asymptotic output tracking when implemented with adaptive parameter estimates. A completely parametrized linear error equation is obtained based on which a stable adaptive law is derived for parameter adaptation in the presence of parameter uncertainties. All closed-loop signals axe bounded and the plant output tracks a given reference output asymptotically, despite the uncertainties in actuator failures and plant parameters, as shown analytically and by simulation results from a case study of yaw rate control of Boeing 747 lateral dynamics.