Reduced-Order Active Disturbance Rejection Control Scheme for a Quadrotor and Its Autotuning Method

The flight performance of unmanned aerial vehicles (UAVs) is severely impacted by wind disturbances. Active disturbance rejection control (ADRC) is expected to improve the UAV's anti-disturbance capability through its component extended state observer. However, the enormous computational effort necessary for calculation and parameter adjustment of conventional ADRC hampers its practical installation in an on-board flight controller. In this study, a reduced-order ADRC technique for both attitude and position control of quadcopters was redesigned for easy implementation in flight controllers. In addition, we developed a practical online autotuning method for attitude control that requires only a few minutes to tune the controller. Several experiments were performed using an actual quadcopter to validate the proposed reduced-order ADRC controller and the autotuning method.