Fuzzy Disturbance Observer-Integrated Trajectory Tracking Control of Quadrotor Unmanned Aerial Vehicles

In this paper, we investigate the trajectory tracking issue of the quadrotor unmanned aerial vehicle (UAV) subject to inner parameter uncertainties and unknown external disturbances. For this purpose, we develop a fuzzy disturbance observer-based trajectory tracking control scheme for the UAV, which guarantees that the position and yaw angle are capable of responding to the reference command in a timely way. The dynamic model of the quadrotor is firstly grouped into a position subsystem and an attitude subsystem by the characteristics of multiple time scales. Secondly, the dynamic surface control method is designed to construct the tracking controllers thereby enhancing the robustness performance of the UAV and obviating the explosion problem of the differential term. Next, the fuzzy disturbance observer is utilized to evaluate the inner parameter uncertainties and unknown external disturbances, which are synthesized during the tracking control phase. In the context of Lyapunov stability theories, we illustrate that the proposed control strategy ensures that the tracking error of the subsystem achieves globally uniformly bounded. Finally, numerical examples are presented to demonstrate the effectiveness and performance of the developed method.