Sliding Mode Control for a Fixed-Wing UAV with Disturbance via Adaptive Dynamic Programming

In this paper, a control scheme is developed for attitude system of a fixed-wing unmanned aerial vehicle (UAV) subject to unknown external disturbance. First, the dynamic equations of attitude system are introduced and the control-oriented model (COM) is established. Then, an adaptive-gain sliding mode (AGSM) algorithm is proposed to handle the effects of unknown external disturbance such that the expected equivalent sliding-mode dynamics can be obtained. Based on the above design, an actor-critic structure-based ADP approach is employed to generate the nearly optimal control law. Finally, the validity of our proposed control scheme is demonstrated via simulation.