ABSTRACT

A simple dynamic positioning (DP) system has been developed for the scaled model of a novel twin-lift decommissioning operation. Such a decommissioning solution involves the two semi-submerged vessels transporting the topside to another vessel. And it requires the synchronised motion of the two topside-carried vessels at a low speed, under the environmental disturbances. In order to ensure efficiency and safety, model tests with a scaling factor of 1:37 have been carried out in the wave tank. The DP system in the experiment consists of a 3-Degree of Freedom (3DoF) motion equation, a Proportional–Integral–Derivative (PID) controller and a thrust allocation algorithm. This paper investigates the motion response of each vessel under the random wave and constant wind of different angles, to assess the low-speed manoeuvring performance. It is found that the given control scenarios allow the twin-lift decommissioning system to yield good motion performance under operational conditions.

摘要

一个简单的动态定位 (DP) 系统已被开发用于新的双升力退役操作的比例模型。这种退役解决方案涉及将两艘半潜船将上部运输到另一艘船。并且它要求两艘上岸船在环境扰动下低速同步运动。为确保效率和安全，在波浪池中进行了比例因子为 1:37 的模型试验。实验中的 DP 系统由 3 自由度 (3DoF) 运动方程、比例-积分-微分 (PID) 控制器和推力分配算法组成。本文研究了每艘船在不同角度的随机波浪和恒定风下的运动响应，以评估低速机动性能。