Non-singular Fast Terminal Sliding Mode and Active Disturbance Rejection Control for Quadrotor UAV

The purpose of this paper is to improve the anti-interference ability of the quadrotor UAV. This paper proposes a non-singular fast terminal sliding mode combined with an active disturbance rejection controller. Firstly, the uncertainty factors, such as model errors and internal and external disturbances of the quadrotor UAV system, are regarded as lumped disturbances, estimated and compensated online by the extended state observer in real-time. According to its underactuated, multivariable, and nonlinear characteristics, it is divided into a position loop and an attitude loop. On this basis, it is transformed into complete drive control by introducing virtual control quantity. The simulation results show that the non-singular fast terminal sliding mode active disturbance rejection controller has better robustness than the cascade active disturbance rejection control.