【作者】 顾楠；

【导师】 缪泉明； 魏纳新；

【作者基本信息】 中国舰船研究院 ， 流体力学， 2011， 硕士

【摘要】 随着人类对海洋资源开发和探索的范围、水深越来越大,人们对深海作业的浮式生产系统(包括船舶、半潜平台)的定位方式的研究日益重视。动力定位系统不同于传统的锚缆系泊,它是一个利用动力来定位的闭环的控制系统。由于有其独特的优势,越来越被广泛地应用于各种海洋平台及船舶。控制算法以及推力分配方法是动力定位控制系统的核心,本文旨在通过对控制系统及多推进器优化分配的研究,建立船舶动力定位数值仿真平台,为动力定位模型试验甚至动力定位样机打下基础。本文主要工作包括如下几个方面:(1)首先建立两套数学模型,分别为控制模型和过程模型。控制模型是一种简化的船舶运动模型,只描述了环境干扰力和船舶运动的主要特征,主要用于控制器、滤波器的设计,及稳定性分析。过程模型描述了船舶受力和运动的真实过程,这种模型更为复杂、精细,主要用于仿真船舶的真实运动,对控制系统进行测试和鲁棒性分析。(2)其次利用控制模型设计用于仿真计算和模型试验的卡尔曼滤波器和LQG控制器。(3)提出一种新的多推进器推力分配算法,可以有效的将三个方向的推力指令优化分配到各个推进器上,并且考虑了对推进器最大推力的限制,推力最大变化速度的限制,方位角的范围,方位角变化的最大速度的限制,也避免了奇异结构的出现。(4)将模型试验结果与数值计算结果进行对比,分析了二者在若干方面的异同,并解释了造成二者差异的原因。本文在如下两方面取得了创新:1)提出了一种新的多推进器推力优化分配算法,并将这种算法应用于7个全回转推进器的深水铺管船的动力定位仿真计算和模型试验中,取得了良好的结果。2)建立了动力定位数值仿真平台,并将仿真计算结果和模型试验结果进行比较,使仿真计算能够为模型试验提供指导,同时对动力定位精度或能力进行评估。更多还原

【Abstract】 The positioning of floating structures is a problem of great concern with the rapid development of exploitation and production in deep seas. Dynamic Positioning system is different to traditional anchor system. Dynamic positioning system is a closed-loop control system to let the marine vessel maintain a fixed position and heading in the horizontal plane, or to follow a predetermined track. Now the DP system is widely applied to floating offshore structures and ships. The objective of this thesis is to establish the simulation program for the DP system by studying on the control method and thrust allocation method. . The major work of the thesis includes:(1) Firstly, two mathematical models were established, one is the control plant model and another is the progress plant model. The process plant model is a model describing the real world as accurate as possible. This model is most often used in numerical simulation as an imitation of the real world. Contrarily, the control plant model is a simplified ship model to be used in controller design. It is the basis when designing controllers and observers, or when doing stability analysis.(2) Secondly, Kalman Filter and LQG controller is designed with the control plant model.(3) The thesis proposed a new thrust allocation method. Thrust allocation problem is formulated as an optimization problem, which objective is to minimize the energy consumption, including fuel consumption, tear and wear of thrusters and thrust error. The boundary conditions include thrust limitation, maximum thrust change rate of thrust, maximum slew rate of thrusts, forbidden sector for the thrust direction angle.(4) The numerical simulation results were compared with those form model test and the consistence was analyzed.The following innovations were obtained:1) A new thrust allocation method which was used in both numerical simulation and model test was established, and good results were obtained.2) The simulation program of DP was developed and was applied to a deep water pipe-laying crane vessel with seven azimuthing Model test results were compared with numerical results and good agreement was obtained.更多还原