Backstepping-based attitude control for a quadrotor UAV using nonlinear disturbance observer

In this article, a backstepping-based control strategy is developed for the attitude control of a quadrotor Unmanned Aircraft Vehicle (UAV). Considering that the quadrotor UAV usually suffers external disturbances to complete practical missions, a nonlinear disturbance observer is introduced to improve the accuracy and robustness of the attitude controller. The disturbances of the system are estimated efficiently by using developed nonlinear disturbance observer. The simulation results are given to demonstrate the effectiveness of the proposed control strategy for the quadrotor UAV during the quasi-static flight.