一种波浪中的船舶动力定位运动建模方法研究

Method of ship motion modeling with dynamic positioning in waves

船舶动力定位是在船舶低速条件下对航向和位置进行控制,控制效果受海浪干扰的影响较大。考虑具有修正PM波谱的长峰不规则浪,基于海浪幅值响应算子(RAO)研究了船舶在海浪中的六自由度运动预报模型。以船舶定点保持模式为例,采用船模实验数据,对海浪作用下的船舶纵荡、横荡和转艏运动进行了数值仿真,给出了运动RAO频率特性曲线和船舶运动时域响应曲线,验证了该方法的有效性。该方法用于船舶在波浪中的运动预报和动力定位系统设计,具有实用性和经济性。

Dynamic positioning system （DPS） is primarily used to control the course and position of ship at low speed, which is primarily influenced by wave disturbance. Considering long-crested irregular waves with modified Pierson-Moskowits （PM） spectrum, a ship motion predictive model in waves with six freedoms is studied based on motion response amplitude operator （RAO）. With the station-keeping as an example and based on ship model experiment data, digital simulation of ship＇s surge, sway and yaw motions in waves is carried out. Frequency characteristics of motion RAO and time-domain response curves of ship motion are presented, which proves the validity of the method. The method can be used in ship motion prediction in waves and design of dynamic positioning system, and has practicability and economic value.