Active Wind Rejection Control for a Quadrotor UAV Against Unknown Winds

This article presents an active wind rejection control scheme for a quadrotor unmanned aerial vehicle (UAV) against unknown winds. Based on the estimated wind effects acting on the aircraft, the proposed control scheme can maintain the performance of the quadrotor UAV in the presence of model uncertainties, unknown winds, and system noises. Firstly, a two-stage particle filter is designed to estimate the UAV states and wind information from the motion of the vehicle without additional wind sensors. Then, an active wind rejection control scheme is proposed to actively attenuate the wind disturbances based on the estimated wind information. In the controller design, the nonsingular terminal sliding-mode control (NTSMC) is chosen as the baseline controller. To tackle the issues of model uncertainties and wind estimation errors, the adaptive drag coefficients are adopted to generate the compensation control signals. Finally, simulation results are presented to demonstrate the effectiveness of the proposed active wind rejection control scheme for a quadrotor UAV against unknown winds.