Robust sliding mode control for quadrotor UAV trajectory based on extended state observer

For the robust trajectory tracking of the quadrotor vehicle, an extended state observer (ESO) based sliding mode control (SMC) is proposed. In the presence of disturbances and unavailable linear velocity, an extended state observer is introduced in the SMC to estimate the uncertain instabilities, with their estimations being compensated in the control, which ensures the quadrotor system robustness and survivability to environment. Besides, the SMC can counteract uncertainties by introducing switching functions. However, the large switching gain may cause system chattering. The incorporation of ESO into SMC alleviates the chattering, due to the superior estimation of uncertainties and their timely compensation in the control. The stability of the controlled system is proved by Lyapunov theorem. Simulation experiment results verify the robustness of the proposed control strategy, and show that the maximum jump-change of the rotor velocity is decreased by 86.4%~94.5%, which improves the system stability. © 2018, Editorial Department of Journal of Chinese Inertial Technology. All right reserved.