动力定位半潜平台五自由度运动控制及其机理研究

发布时间：2018-09-12 08:56

【摘要】：动力定位系统在设计过程中,通常只将水平面内的三自由度运动(横荡、纵荡和首摇)作为控制目标,但是对于水线面较小的海洋结构物,例如半潜平台,由推进器推力和波浪联合作用所产生的横摇和纵摇在部分海况下较为明显,对人员的生活和操作以及平台的生产效率和安全都会产生一定的影响。国内外关于半潜平台的五自由度运动控制所开展的研究较少,现有的研究提出了相关的控制模型,但是关于横纵摇运动的机理却少有涉及。因而,本论文将提出一种新的控制策略,本策略在原有的三自由度控制策略的基础上,添加横摇和纵摇的角度、角速度和角加速度作为补充的参考变量。首先,对横纵摇运动加剧的原因进行简单总结,并提出推进器推力使横纵摇运动加剧的四种模式;其次,结合新提出的控制策略,基于现有的内部程序的基础上,对程序进行二次开发,对半潜平台的五自由度运动进行时域模拟,检验该策略的控制效果;最后,将五自由度情况下的定位效果与三自由度情况下的定位效果进行比较,以检验五自由度控制策略对于三自由度定位精度的影响,并且依据时域模拟的结果,对控制策略做出相应的修改和微调。通过对比发现,新提出的五自由度控制策略对于平面三自由度的定位效果影响较小,同时对于横摇和纵摇的抑制较为明显。
[Abstract]:In the design of a dynamic positioning system, only three degrees of freedom (swinging, swinging and swaying) in the horizontal plane are usually used as control targets, but for offshore structures with smaller waterlines, such as semi-submersible platforms, The rolling and pitching produced by the combined action of thruster thrust and wave are obvious in some sea conditions, which will have a certain impact on the life and operation of the personnel, as well as the production efficiency and safety of the platform. There are few researches on the motion control of semi-submersible platform with five degrees of freedom at home and abroad. The existing research has put forward the relevant control model, but the mechanism of rolling motion is seldom involved. Therefore, a new control strategy is proposed in this paper. Based on the original three-degree-of-freedom control strategy, the angle of roll and pitch, angular velocity and angular acceleration are added as supplementary reference variables. First of all, the causes of the acceleration of rolling motion are summarized, and four modes of thruster thrust are put forward. Secondly, combined with the new control strategy, based on the existing internal procedures, The program is redeveloped to simulate the motion of the semi-submersible platform with five degrees of freedom in time domain to test the control effect of the strategy. Finally, the positioning effect under the condition of five degrees of freedom is compared with that under the condition of three degrees of freedom. In order to test the effect of the control strategy of five degrees of freedom on the positioning accuracy of three degrees of freedom, the control strategy is modified and fine-tuned according to the results of time domain simulation. Through comparison, it is found that the new five-DOF control strategy has little effect on the positioning effect of plane three-degree-of-freedom, and the suppression of rolling and pitching is more obvious.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U664.82

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