基于扰动观测器的AUV固定时间积分滑模控制方法

Fixed-time integral sliding mode control method for AUV based on disturbance observer

针对自主水下航行器(AUV)在参数不确定性和外界干扰下水平轨迹跟踪控制问题,提出一种基于扰动观测器的固定时间积分滑模控制方法。首先将参数不确定性和外界干扰视为复合扰动,设计固定时间扰动观测器对其进行估计。然后在反步法设计框架下,结合固定时间理论和全局积分滑模控制,设计了固定时间积分滑模控制器。轨迹跟踪仿真结果表明,相比于传统滑模控制器,所设计的扰动观测器和控制器可以使位置和姿态的跟踪误差收敛至零域的速度由5.2 s缩短至约2.5 s,并且在没有观测器的帮助下跟踪误差也能收敛至稳定,具有更快的收敛速度和更高的鲁棒性。

Aiming at the horizontal trajectory tracking control problem of autonomous underwater vehicle(AUV)under the parameter uncertainty and external interference,a fixed-time integral sliding mode control method based on disturbance observer is proposed.Firstly,the parameter uncertainty and external interference are regarded as compound disturbances,and a fixed-time disturbance observer is designed to estimate them.Then,a fixed-time integral sliding mode controller is designed by combining the fixed-time theory and global integral sliding mode control under the framework of backstepping design.Trajectory tracking simulation results show that compared with the traditional sliding mode controller,the proposed disturbance observer and controller can shorten the convergence speed of position and attitude tracking errors to zero domain from 5.2 s to 2.5 s,and the tracking error can also converge to stability without the help of the observer,which has faster convergence speed and higher robustness.