Composite Disturbance Rejection Attitude Control for Quadrotor with Unknown Disturbance

In this article, a composite disturbance rejection control method is proposed for attitude control of quadrotor using an inner-outer loop control framework, which can effectively improve the angular tracking performance of the quadrotor and achieve the active disturbance rejection. In the inner loop, a novel nonlinear extended state observer (NESO) is designed to estimate the disturbance and nonlinear part of the system model, then a robust control law is embedded in inner-loop controller to attenuate the effect of the estimation error. In the outer loop, a composite nonlinear feedback (CNF) controller is designed to improve the transient performance. Moreover, the stability of two loops are also analyzed, respectively. Numerical simulation and platform experiment are carried out to verify the efficiency of the proposed method.