Rate control and flight stabilization for a quadrotor system

In this paper we propose a stability augmentation system for a quadrotor, enabling direct rate control for a human pilot. Our system includes feedforward for rate control, feedback for disturbance attenuation, and an online optimization technique for handling input restrictions. We show that the proposed algorithms are able to stabilize the system under highly challenging flight conditions, such as wind gusts and fast manual descend. Our input restriction technique ensures that the revolution speeds for the desired torques are feasible. The complete control system is analyzed using MATLAB, and full experimental validation is provided based on a quadrotor prototype.