Trajectory tracking control of quadrotor aircraft based on improved ESO backstepping sliding mode

The trajectory tracking precision of quadrotor aircraft is affected by external interference and system parameter perturbation. In order to solve the problems, a robust control method based on improved high-order extended state observer(ESO) and block backstepping sliding mode is proposed in this paper. At first, the system model of quadrotor aircraft is divided into two subsystems of position part and attitude part. Then, the perturbations and external disturbances of the system are the uncertainty term, and an improved ESO is designed to estimate them. The estimated value is compensated timely in controller, thus the position trajectory tracking accuracy is improved efficiency. Moreover, the system structural with strong coupling characteristic, thus a robust controller is designed based on the block backstepping and sliding mode method for the attitude part. The block backstepping is contributed to solve the limitation of the traditional sliding mode method under the unmatched condition effectively, so the control attitude of the system is ensured. Meanwhile, the stability of the system is proved by Lyapunov stability theory. The simulation results demonstrate that the effectiveness of the method in this paper, and it can realize the accurate trajectory tracking for quadrotor.