欠驱动船舶非线性滑模靠泊控制器

Berthing controller of underactuated ship with nonlinear sliding mode

为了准确控制典型靠泊操纵,分析了带有加速度非完整约束的欠驱动水面船舶的自动靠泊问题,设计了动态输出反馈控制器。利用递归分解迭代设计方法,在扩展状态空间定义了非线性滑模,将控制系统的轨迹设计与跟踪问题转化为标量零阶系统的镇定控制问题,结合增量反馈技术,无需对不确定模型参数以及风、流干扰进行估计,完成典型靠泊操纵的自动控制。仿真结果表明:控制器对干扰变化不敏感,具有强的鲁棒性,且船舶平面运动轨迹设计过程简单,可以仅通过一个参数进行轨迹调节。

In order to accurately control typical berthing steering,a dynamic output feedback controller was designed for the automatic berthing of underactuated surface ship with nonholonomic acceleration constraints.The control problems of path planning and following were transformed into the static control problem of scalar zero-order-systems by means of iterative sliding mode control（ISMC）,in which nonlinear sliding surfaces were recursively and iteratively designed in augmented state space.Integrating with increment feedback,the controller was proved to stabilize ship＇s motion in typical berthing steering without estimating systemic uncertainties and the disturbances resulted from current and wind.Numerical simulation result shows that the controller is strongly robust to the variation of the disturbances,and ship＇s planar trajectory is adjusted by using only one variable due to its simple design procedure.7 figs,15 refs.