Linear adaptive actuator failure compensation for wing rock motion control

In this paper, a novel adaptive actuator failure compensation control strategy is developed for wing rock motion control in the presence of both system and actuator failure uncertainties. The proposed strategy can compensate for both total and partial loss of effectiveness. A proportional actuation scheme of redundant aileron segments is used. This allows bringing the faulty multi-input single-output nonlinear system into an equivalent perturbed single-input single-output system. Afterward, an adaptive actuator failure compensation control scheme is developed around a linear approximation of an ideal feedback linearization controller. A failure estimation and compensation term is appended to this controller to account for possible actuator failures. Closed-loop stability and tracking performance are proved based on Lyapunov theory and a piecewise analysis is also introduced to show that stability properties hold despite the presence of parameter jumps caused by abrupt actuator failures. Simulation results on a small scale wind tunnel based wing rock model with redundant actuators show the effectiveness of the proposed adaptive control strategy.