Terminal Sliding Mode Control of a Quadrotor UAV Based on Disturbance Observer

A efficient nonsingular terminal sliding mode control strategy for quadrotor UAV trajectory tracking is proposed, incorporating a super-twisting disturbance observer to handle complex disturbances. Firstly, an estimation of external disturbances on the UAV system is performed using a supertwisting disturbance observer. Subsequently, considering the structural characteristics and control requirements of the UAV system, fast nonsingular terminal sliding mode controllers based on the disturbance observer are designed for both position and attitude loops. The stability of the system reaching convergence in finite time is proven based on Lyapunov theory. Finally, simulation analysis demonstrates the excellent control performance of this strategy.