Research on Adaptive Fault-Tolerant Control of Quadrotor UAV Based on Improved Nonlinear Extended State Observer

In this paper, a parameter-uncertain quadrotor UAV system with unknown external disturbances and actuator failures is studied, and a parameter adaptive fault-tolerant control scheme is based on an improved nonlinear extended state Man-machine trajectory tracking control. First, considering the influence of the unknown multi-source external environmental disturbance on the quadrotor UAV, the external disturbance suffered by the system is estimated and compensated in real-time by introducing an improved nonlinear extended state observer. Secondly, a new type of sliding mode reaching law is designed by using the continuous function with relay characteristics combined with the exponential function, which improves the sliding mode response speed of the system and eliminates the chattering of the sliding mode. Finally, a parameter adaptive law is designed for the actuator fault, and an adaptive fault-tolerant controller is designed by combining the backstepping sliding mode method, and the stability of the control system is proved by using the Lyapunov stability theory.