High-performance trajectory tracking control of a quadrotor with disturbance observer

In this paper, a flight controller with disturbance observer (DOB) is proposed for high-performance trajectory tracking of a quadrotor. The dynamic model of the quadrotor, considering the external disturbances, model mismatches and input delays, is firstly developed. Subsequently, a DOB-based control strategy is designed with the backstepping (BS) technique. In this control scheme, the DOB serves as a compensator, which can effectively reject model mismatches and external disturbances. In this case, the trajectory tracking controller is designed according to the nominal model. Then, the input-to-state stability (ISS) analyses of the developed controllers are presented, which theoretically guarantees the robustness of the developed controller. Finally, comparative studies are carried out. Three types of disturbances including payloads, rotor failures and wind are chosen to verify the effectiveness of the development. The results from simulations and experiments show that the proposed controller provides better performances than the traditional nonlinear controllers.