Development of Dynamic Positioning System for Deep Sea Floating Structure

浮式海洋平台是开发海洋矿产资源的一种有效手段，目前已有大量的浮式海洋平台投入使用。使用说明书要求平台在海流、风或波浪等外力作用下保持位置。通常采用锚泊系统或推进器动力定位系统来保持船舶的位置。然而，以往的系统不能很好地防止慢漂振荡。后一种系统由于推进器需要持续逆流或逆风工作，需要消耗大量的能量，本文采用推进器辅助系泊系统。在该系统中，系泊用于抵抗水流和风的外力而保持位置。推进器用于防止慢漂移振荡。通过实验和计算，获得了作用在浮式平台模型上的水动力，并设计了控制器。根据运动模拟的结果，验证了能量降低。

A floating offshore platorm is useful to develop mineral resources in the ocean and a lot of platform are being operated. The directions for use requires that platforms keep the position under the external forces such as ocean current, wind or waves. Generally, mooring system or dynamic positioning system by thrusters are used to keep the potision. However, the former system can not prefectly prevent the slow drift oscillation. The latter system requires a lot of energy because the thrusters have to work continually against current or wind.In this paper, thruster assisted mooring system is adopted. In this system, mooring is used to keep the position against the external forcde by current and wind. The thrusters are used to prevent the slow drift oscillation. The it is expected that the energy to keep the position is remarkably reduced.Experiments and calculations to obtain hydrodynamic forces acting on a floating platform model were carried out and controller was designed. From the results of simulation of motions, it was verified that the energy is reduced.