Trajectory Tracking Control of Quadrotor Drones Based on Disturbance Observers

A composite control method is proposed by combining a disturbance observer with sliding mode control to address the uncertainties of parameters, models and external disturbances in the position and attitude control system for quadrotor unmanned aerial vehicles (UAVs). The observer estimates the equivalent disturbances in real-time, and a sliding mode controller is designed based on these estimates to track the desired signals. The designed controller not only ensures the system's asymptotic stability but also effectively suppresses the impact of internal and external disturbances. Finally, simulations verify the effectiveness of the proposed method.