欠驱无人水面船有限时间自抗扰循迹控制方法

Finite-time active disturbance rejection path following control method for underactuated unmanned surface vessels

针对欠驱无人水面船在外界时变环境干扰和模型不确定影响下如何提高循迹控制性能的问题,提出了一种带漂角观测器的有限时间自抗扰循迹控制方法.首先,基于有限时间稳定性理论设计有限时间非线性干扰观测器,对时变大漂角进行在线估计,并结合视线法引导律(LOS),提出有限时间引导律(FLOS),提高引导系统的响应速度和鲁棒性,使得船舶快速收敛至期望路径,并稳定地沿着期望路径航行;然后,结合反步控制和二阶滑模控制进行有限时间控制器设计,将模型不确定性、时变环境干扰和虚拟控制量视为总扰动,对其进行观测并补偿,设计有限时间自抗扰控制器(FADRC),使纵向和艏向控制系统误差在有限时间内收敛至零附近;最后,通过仿真验证了提出方法的有效性.

Aiming at the problem of how to improve the path following control performance of underactuated unmanned surface vessels under the influence of external time-varying environmental disturbance and model uncertainty,a finite-time active disturbance rejection path following control method with drift angle observer was proposed.First,a finite-time line-of-sight(FLOS)guidance law based on finite-time stability theory was proposed by combining the line-of-sight guidance law and a nonlinear disturbance observer which was used to estimate the time-varying large drift angle,which could make the unmanned surface vehicle quickly converge to the desired path and sail along the expected path stably,and improve the response speed and robustness of the guidance system.Then,a finite-time active disturbance rejection controller(FADRC)was designed to make the longitudinal and heading control system errors converge to near zero in finite time by combining the backstepping control and smooth second-order sliding modes method,considering the model uncertainty,time-varying environmental disturbance and virtual control as the total disturbances which could be observed and compensated.Finally,the effectiveness of the proposed method was verified by simulation.