基于ESO和动态逆的欠驱动船舶航迹跟踪控制设计

针对欠驱动船舶航迹跟踪控制问题,考虑船舶动态不确定性、未知时变外部扰动和速度不可测的情况,将输出重定义方法、扩张状态观测器(extended state observer, ESO)和动态逆控制方法相结合,设计欠驱动船舶航迹跟踪控制律。输出重定义方法用来解决系统欠驱动问题；构造ESO,估计由船舶动态不确定性、未知时变外部扰动以及船舶各自由度运动状态变量间的耦合构成的总扰动和船舶速度；基于上述,采用动态逆控制方法,设计航迹跟踪控制律,使欠驱动船舶跟踪期望航迹,并保证航迹跟踪闭环控制系统所有信号最终一致有界。以一艘欠驱动船舶为例进行仿真研究,仿真结果验证了所设计的航迹跟踪控制律的有效性和优越性。

Trajectory Tracking Control Design of Underactuated Ships Based on ESO and Dynamic Inversion

For the trajectory tracking control problem of underactuated ships, a trajectory tracking control law for underactuated ships is designed through combining the output redefinition method, an extended state observer(ESO) and the dynamic inversion control method in the presence of dynamics uncertainties, unknown time-varying external disturbances and unavailable ship velocities. Herein, the output redefinition method is used to solve underactuation problem. An ESO is constructed to estimate the compound disturbances induced by ship dynamics uncertainties, unknown time-varying external disturbances and coupling between the ship motion state variables, and velocities of ships. The trajectory tracking control law for underactuated ships is designed incorporating the above into the dynamic inversion control method such that the underactuated ship can track the desired trajectory, while guaranteeing the global uniform ultimate boundedness of all signals in the ship trajectory tracking closed-loop control system. Simulation results on a underactuated ship demonstrate the effectiveness and the superiority of the designed trajectory tracking control law of underactuated ships.