基于super-twisting二阶滑模算法的作业型ROV路径跟踪控制方法

Trajectory Tracking Control Method of a Work-class ROV Based on a Super-twisting Second-order Sliding Mode Controller

作业型遥控无人水下航行器(ROV)的运动存在时变外界干扰和系统不确定性,利用常规滑模方法设计其运动控制器会产生抖振现象,而常用的饱和函数联合边界层法(SatSMC)在消除抖振的同时无法保证控制精度。针对上述问题,文中设计了super-twisting二阶滑模控制器(STSMC)来实现作业型ROV的空间路径跟踪。利用Lyapunov方法分析了系统的稳定性,并证明该方法能够保证跟踪误差在有限时间内收敛。将提出的STSMC与SatSMC及比例-积分-微分法进行了仿真试验对比,结果表明:STSMC能够使ROV完成对既定路径的跟踪,并具有更好的鲁棒性、快速性和控制精度,同时产生的抖振也明显小于SatSMC,控制参数也未增加,更适于ROV的实际使用。

Time-varying external disturbances and system uncertainties affect the motion of work-class remote-operated vehicles(ROVs).The conventional sliding mode method for ROV motion control has the drawback of a chattering phenomenon,whereas the common method for eliminating chattering,namely,the saturation function combined with a boundary layer sliding mode controller(SatSMC),cannot guarantee control accuracy.To address these problems,a super-twisting second-order sliding mode controller(STSMC)is proposed to realize trajectory tracking of a work-class ROV.The Lyapunov method is used to analyze the stability of the system.It is proved that the proposed controller can ensure the convergence of a tracking error in finite time.A simulation experiment of the proposed STSMC and SatSMC methods and the proportional integral derivative(PID)control are compared.Results show that the STSMC method enables the ROV to complete the tracking of a predetermined path.This method also has stronger robustness,rapidity and accuracy.The chattering of the STSMC is also significantly reduced compared to that of the SatSMC.In addition,the control parameters are not increased,making the STSMC more suitable for actual use with ROVs.