基于扩张状态观测器和反步滑模法的四旋翼无人机轨迹跟踪控制

为了解决欠驱动四旋翼无人机（UAV）在实际飞行中存在的外界干扰问题，同时提高在系统参数摄动情况下的精确轨迹跟踪效果，设计了一种基于扩张状态观测器（ESO）和积分型反步滑模算法的飞行控制策略。首先，根据系统的半耦合特性和严反馈结构特点，采用反步法设计姿态内环和位置外环控制器；然后，将抗干扰能力较强的滑模控制融入其中，使得系统的鲁棒性得到增强；接着，为了减小系统的稳态误差，引入积分环节；最后，利用ESO实时估算出系统的内、外总扰动并对控制量进行补偿。通过Lyapunov稳定判据，可以说明该系统是一个全局渐进稳定的系统，并通过仿真分析验证了所提控制方法的有效性和鲁棒性。

Trajectory tracking control for quadrotor UAV based on extended state observer and backstepping sliding mode

To solve the problems of external disturbances and the uncertainty of system model parameters for the underactuated quadrotor Unmanned Aerial Vehicle (UAV) existing in actual flight, a flight control scheme based on Extended State Observer (ESO) and integral backstepping sliding mode was designed. Firstly, according to the semi-coupling characteristics and the strict feedback architecture of system, a backstepping control was adopted to design the attitude inner loop and the position outer loop controllers. Then, a sliding mode algorithm with strong anti-jamming ability and integral control were incorporated to enhance system robustness and reduce static error respectively. Finally, ESO was used to eliminate the total internal and external disturbances and to compensate the interference in the control law online. The closed-loop control system was proven to be globally asymptotically stable by the Lyapunov stability analysis. In addition, the effectiveness and robustness of the proposed flight control scheme were verified through simulation analysis.