A backstepping sliding mode control based on fuzzy disturbance observer for Aerospace Vehicle

A robust and adaptive hybrid control strategy is presented for the aerospace vehicle (ASV) with violent changes of aero-dynamics parameters and external disturbance. To achieve high precision, a novel fuzzy disturbance observer is employed to compensate for the unknown uncertainty. Backstepping method is used to design the sliding surface and then a variable structure controller is obtained. All signals in the closed loop systems are ultimately bounded and output tracking error exponentially converges to an arbitrary small compact by Lyapunov approach. Moreover, there are only two adaptive parameters needed to be tuned on line. Finally, six-degree-of-freedom (6 DOF) numerical simulation results demonstrate that the proposed method has strong robustness.