Sliding Mode Control for VTOL Aircraft Based on High-Gain Observer

Based on the high-gain observer technique, this paper proposes a sliding mode control strategy for VTOL aircraft. The merit of this control strategy is that this paper gets exponential stability results of VTOL aircraft tracking control system. VTOL aircraft is a typical nonlinear underactuated system, based on the characteristics of this model, after four reversible coordinate transformation, the original mathematical model is transformed into a coordinate standard mode, then design a sliding mode controller. Another challenge for control design is that some states needed in the control schemes are not available. In order to solve this problem, a high-gain observer is utilized. The stability of the closed-loop system is verified via Lyapunov method and separation principle. The simulation results show that this method can solve VTOL aircraft trajectory tracking problem using only output feedback.