【作者】 宋杨；

【导师】 林焰； 张明霞；

【作者基本信息】 大连理工大学 ， 船舶与海洋结构物设计制造， 2013， 博士

【摘要】 海上航行船舶受到海洋风浪流干扰后,将产生六个自由度运动,其中横摇运动对船舶的影响最大。剧烈的横摇运动不仅使船员无法正常工作,严重的有可能导致设备仪器失灵,甚至有可能导致船舶海难事故的发生,造成环境污染和财产生命等重大损失。如何有效地避免这种现象的发生是目前船舶运动控制领域的热门课题。为保证船舶安全航行,首先要研究海洋环境的特性,以便研究海洋环境对船舶的扰动作用,分析航行于海上的船舶一般运动规律。其次要研究船舶横摇运动的动力学特性,分析引起横摇运动难于控制的原因。此外要研究选用什么样的装置来控制横摇运动、典型的控制系统各组成部分的作用,以及常用的控制器的形式。最后要引入新的控制算法以提高控制系统的控制效果,从而达到控制横摇,并安全航行的目的。本文以船舶的横摇运动为研究对象,在分析其动力学特性后,重点研究了横摇运动减摇控制的新策略,具体研究内容如下：(1)基于改进的希尔伯特-黄变换方法对船舶大幅横摇运动的非线性响应特性的分析研究。深入研究了希尔伯特-黄变换方法的实现过程,并结合船舶横摇运动时序呈现出非线性、随机性和非平稳性等特征的特点,提出了改进的希尔伯特-黄变换分析方法。改进的算法以滑动窗口技术和三次B样条理论为基础,提高了分解速度,使得实时经验模态分解名副其实。改进算法在船舶横摇运动的响应特性分析中的应用,不仅扩展了该方法的应用领域,同时,更深入地分析了船舶横摇运动的频率构成因素,分析了横摇运动难于控制的原因所在,为基于无模型控制理论在船舶横摇运动控制中的应用奠定基础。(2)基于多新息理论、跟踪微分器技术和混沌遗传优化算法的改进标准无模型自适应控制理论研究。深入分析了模型控制策略和经典控制策略(PID控制)在船舶减摇控制系统中存在的问题,提出了无模型自适应控制策略引入的必要性和可行性。针对船舶减摇控制系统的特点,提出了三点改进：第一,通过理论推导及仿真验证了基于多新息理论用于改进无模型自适应控制方法的可行性,因改进无模型自适应控制方法中控制律形式的改变,在保证良好的跟踪性能的前提下,提高了控制算法的收敛速度。第二,通过仿真验证了将跟踪微分器技术用于改进无模型自适应控制方法的可行性,因跟踪微分器技术的引入,增强了控制算法的抗干扰能力。第三,将智能优化算法-混沌遗传算法融合在改进的无模型控制方法中,提高了算法的自适应能力。(3)将改进的无模型自适应控制算法作为新的控制策略,应用于船舶减摇控制系统中。以单一减摇鳍减摇系统及减摇鳍-减摇水舱联合减摇系统为被控系统,通过与传统PID控制、标准无模型自适应控制策略的控制效果对比,验证了本文所提出的改进方法的有效性和实用性。(4)船舶在不规则海浪中运动的仿真研究。开发设计了船舶摇荡运动的仿真平台。该平台具有界面简单、实时运算速度快和三维显示的特点,不仅可为科研工作人员提供船舶的运动规律,为船舶的设计提供理论基础,同时可直观观察船舶的实时三维运动形态,为船舶的减摇控制提供了一种可视化、形象生动的表现形式。更多还原

【Abstract】 Disturbed by the wave and wind, the sailing ships have six degrees of freedom motions. When the condition is bad, rolling has the largest effect of the six degrees of freedom motions. The severe rolling not only makes the crew can’t work, but also might lead to equipment instruments failure. The serious rolling may even create capsizing accidents, heavy losing of property, environmental pollution and effects on life safety.Currently, how to effectively avoid this phenomenon occurred is a hot topic in the field of ship motions control. In order to ensure the safety of navigation ships, firstly, the characteristics of the wave environment should be studied, so the disturbed effects on the ship will be studied and the disciplines of the ship motions in the wave will be achieved. Secondly, the dynamic characteristics of the ship rolling motion should be studied, and then the reason of hard controlling of the ship rolling can be found. Thirdly, what kind of anti-rolling equipment will be chosen should be analyzed and what kind of control strategy will be chosen should be verified. At last, the new and effective control strategy should be studied to get the better anti-rolling effects for the purpose of safe navigation.Therefore, the ship rolling motion was chosen as the research object, after the analysis of its dynamic characteristics, the paper is focusing on the rolling reduction strategy. The specific studies are as follows:(1) On the basis of the overview of ship rolling methods for analysis of nonlinear dynamic characteristics at domestic and foreign, the Hilbert-Huang Transform (HHT) method was introduced into the analysis of the ship nonlinear dynamic characteristics, the sliding widows technique and the three B spline theory were applied into the improved HHT method, which not only extends the application field of the HHT method, but also provides a new idea for the characteristics analysis of the ship rolling motion. At the same time, the frequency components of the rolling motion were discussed and the reason that the rolling motion is difficult to control was analyzed, which provide the foundation of the application of the model-free control methods on the ship rolling motion control.(2) The standard MFLAC method and the PID method were introduced in the paper, according to the shortcomings of the application of standard MFLAC method on the ship anti-rolling system, the improved MFLAC method was studied, including the MI theory> the TD technology and the CGA algorithms. The improved MFLAC based on MI theory has the better convergence speed. The improved MFLAC based on TD technology has the stronger ability of anti-interference. The improved MFLAC based on CGA has the better adaptive ability.(3) On the basis of the overview of the ship rolling control methods at home and abroad, the improved MFLAC method was introduced into the area of the ship anti-rolling control. The single fin stabilizer system and the integrated fin and anti-rolling tank system were chosen as the controlled system. Compared with the traditional PID control method, the standard MFLAC method, the effectiveness and the practical application of the improved method were verified.(4) The simulation platform of ship motions was designed. The platform has the simple interface, the rapid calculation ability and the feature of3D display. It not only can provide the disciplines of the ship motions in the irregular wave, which bring the theoretical guidance for the safe navigation, but also can be intuitive to observe the real-time motions, at the same time, the control effect can be shown in this platform, which provides the visual, vivid form of expression about the control methods.更多还原