ABSTRACT

A path following control strategy is proposed for the guide ship in the underway replenishment without velocity measurements. Firstly, the detailed models of the ship and external disturbances are established. Secondly, an extended state observer is designed to estimate the linear speeds and yaw rate of the ship based on the information of position, heading, propeller speed and rudder angle. With the estimated linear speeds, the sideslip angle led by the disturbances is obtained and thus can be compensated by the update law of the desired heading. Also, an augmented state in this observer is constructed to approximate the system uncertainties and disturbances. Thirdly, two command filter backstepping controllers companied with the observer are proposed to directly control the propeller and rudder, respectively. For the proposed control system, its stability is proved by using the Lyapunov theory. Finally, the effectiveness of the proposed method is demonstrated by a simulation example.

摘要

针对在航补给中的导流船，提出了一种路径跟随控制策略，无需测速。首先，建立了船舶和外部干扰的详细模型。其次，设计了一个扩展状态观测器，根据位置、航向、螺旋桨速度和舵角等信息估计船舶的线速度和偏航率。通过估计的线速度，获得了由扰动引起的侧偏角，因此可以通过期望航向的更新规律进行补偿。此外，该观测器中的增强状态被构造为近似系统的不确定性和干扰。第三，提出了两个与观测器相伴的命令滤波器反步控制器，分别直接控制螺旋桨和方向舵。对于建议的控制系统，用李雅普诺夫理论证明了它的稳定性。最后，通过一个仿真例子证明了所提方法的有效性。