Two-level robust adaptive fuzzy control of aircraft

Aircraft are non-minimum phase, MIMO and highly nonlinear systems which undergo significant disturbances and variation in system parameters during operation. In spite of the prosperous literature in adaptive control, application of the promising control strategy on aircraft control has been restricted by the lack of assurance in closed-loop stability. This paper proposes a robust adaptive control scheme for aircraft. The scheme is composed of an inner-level adaptive fuzzy PD control law and an outer-level supervisory control law. Importantly, the outer-level controller of the two-level scheme is designed based on a fuzzy model which takes non-minimum phase phenomena and modeling error explicitly into account. Numerical studies of the tracking control of a five degree of freedom aircraft system demonstrate the effectiveness of the proposed control strategy in the face of bursting disturbances.