Backstepping Sliding Mode Control for Quadrotor UAV Based on Adaptive Observer

This paper considers the accurate trajectory control of quadrotor unmanned aerial vehicles (UAVs) under the presence of both actuator faults and uncertain disturbances. A new approach that combines an adaptive observer with a backstepping sliding mode control method is proposed. The proposed adaptive observer is designed to accurately observe and compensate for the uncertain faults and external disturbances in a quadrotor system. Stability analysis shows that the error of trajectory control by the proposed controller is guaranteed to converge to zero when both actuator faults and uncertain disturbances are present in a quadrotor system. Simulation results show that the proposed controller can achieve performance better than that of a few other control methods for the trajectory control of quadrotor UAVs under the presence of both actuator faults and uncertain disturbances.