采用模糊扩张状态观测器的四旋翼无人机滑模轨迹跟踪控制

针对四旋翼无人机(UAV)的轨迹跟踪控制存在外界未知扰动的问题，提出一种基于模糊扩张状态观测器的非奇异快速终端滑模控制算法.首先，根据双闭环控制结构分别对姿态内环、位置外环引入模糊扩张状态观测器，利用该观测器对系统所受到外部总扰动进行在线估计.然后，根据模糊扩张状态观测器的观测值，设计非奇异快速终端滑模控制器，保证四旋翼无人机的状态变量可在有限时间内收敛于期望轨迹.最后，根据李亚普诺夫理论，得出四旋翼无人机系统的闭环稳定性，并通过仿真对比实验验证该控制算法的优越性.结果表明：所提的控制算法可以提高跟踪性能，并有效增强系统的抗外界干扰能力.

Sliding Mode Trajectory Tracking Control for Quadrotor Unmanned Aerial Vehicle Using Fuzzy Extended State Observer

A nonsingular fast terminal sliding mode control algorithm based on fuzzy extended state observer is proposed to solve the problem of unknown disturbances in the trajectory tracking control of a quadrotor unmanned aerial vehicle(UAV). Firstly, according to the double closed-loop control structure, fuzzy extended state observers are introduced into the inner attitude loop and the outer position loop respectively, and the observer is used to estimate the total external disturbance of the system on-line. Then, a nonsingular fast terminal sliding mode controller is designed based on the observed value of the fuzzy extended state observer to ensure that the state variables of the quadrotor UAV can converge to the desired trajectory in finite time. Finally, the closed-loop stability of the quadrotor UAV system is derived based on Lyapunov theory, and the superiority of the control method is verified through simulation and comparison experiments. The results show that the proposed control algorithm can improve the tracking performance and effectively enhance the system’s resistance to external disturbances.