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船舶动力定位系统与锚泊辅助动力定位系统的时域模拟比较 总被引:2,自引:0,他引:2
以低频时域水平运动方程为基础,考虑各种低频载荷作用以及动力定位模型,建立起一种船舶动力定位的时域模拟系统,对某一驳船在只有动力定位系统和拥有锚泊辅助动力定位系统的情况下进行时域模拟,并比较了两种情况下的定位性能和功率消耗情况。 相似文献
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针对长年累月定位在深海恶劣海况下的浮式生产储卸油装置(Floating Production Storage and Offloading vessels,FPSOs)的作业安全问题,本文提出了一种基于缆线结构性的锚泊辅助动力定位滑模控制方法。通过引入结构可靠性因子,表征锚泊系统缆线的安全,在此基础上设计一种新型滑模控制器,通过控制结构可靠性因子和艏向以达到FPSO锚泊辅助定位目的,并证明了系统的稳定性。通过一系列的仿真实验,证明了所提出的基于结构可靠性滑模控制器的有效性、安全性和节能性。 相似文献
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锚泊线的时域及频域动力分析 总被引:2,自引:1,他引:1
本文提出了锚泊线动力分析的一种计算方法,即应用摄动法对非线性锚泊线动力方程作摄动展开,将得到的一阶摄动方程在频率域内求解;然后对频率域解-频率响应函数作Fourier反变换,得到时域内的脉冲响应,再根据给定的输入计算时域响应历程。本文还介绍了为验证这一方法所进行的模型试验。通过模型试验得到了锚泊线的频率响应函数,与理论计算基本符合。 相似文献
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Mooring systems are usually adopted to position floating structures, including mooring lines and anchors, and directly determine the safety of floating structures. Seabed inspection reported that seabed trenches induced by mooring line-soil interaction appear in front of the anchor and reduce the anchor bearing capacity. This work first introduces the research progress of mooring line-soil interaction and seabed trenching simulation. Research about the suction anchor capacity in clay and sand is... 相似文献
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远海作业锚泊定位大型抓斗船时域耦合分析 总被引:2,自引:2,他引:0
在环境复杂、作业水深较大的远海开敞海域进行作业时,大型抓斗船需采用锚泊定位方式,且船体运动响应受风浪影响较大。同时,在抓斗提升和旋转过程中,抓斗运动速度快,提升质量大,抓斗出水时全船所受载荷发生瞬时变化,加上复杂环境载荷的作用,对船舶安全具有很大影响。以适用于远海开敞海域、采用锚泊定位方式的200m3级大型抓斗疏浚船为研究对象,建立了船舶的水动力计算模型,对其运动响应RAO和载荷RAO进行了计算分析。考虑船舶主体、抓斗及锚泊系统之间耦合作用的影响,对抓斗作业时提升和旋转过程中船舶运动响应和锚泊线张力进行时域动力分析,得到了该船动力载荷结果,为后续的设计工作提供基础。 相似文献
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《船舶与海洋工程学报》2016,(4)
This paper focuses on the problem of control law optimization for marine vessels working in a dynamical positioning(DP) regime. The approach proposed here is based on the use of a special unified multipurpose control law structure constructed on the basis of nonlinear asymptotic observers, that allows the decoupling of a synthesis into simpler particular optimization problems. The primary reason for the observers is to restore deficient information concerning the unmeasured velocities of the vessel. Using a number of separate items in addition to the observers, it is possible to achieve desirable dynamical features of the closed loop connection. The most important feature is the so-called dynamical corrector, and this paper is therefore devoted to solving its optimal synthesis in marine vessels controlled by DP systems under the action of sea wave disturbances. The problem involves the need for minimal intensity of the control action determined by high frequency sea wave components. A specialized approach for designing the dynamical corrector is proposed and the applicability and effectiveness of the approach are illustrated using a practical example of underwater DP system synthesis. 相似文献
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《船舶与海洋工程学报》2015,(2)
Loads generated after an air crash, ship collision, and other accidents may destroy very large floating structures(VLFSs) and create additional connector loads. In this study, the combined effects of ship collision and wave loads are considered to establish motion differential equations for a multi-body VLFS. A time domain calculation method is proposed to calculate the connector load of the VLFS in waves. The Longuet–Higgins model is employed to simulate the stochastic wave load. Fluid force and hydrodynamic coefficient are obtained with DNV Sesam software. The motion differential equation is calculated by applying the time domain method when the frequency domain hydrodynamic coefficient is converted into the memory function of the motion differential equation of the time domain. As a result of the combined action of wave and impact loads, high-frequency oscillation is observed in the time history curve of the connector load. At wave directions of 0° and 75°, the regularities of the time history curves of the connector loads in different directions are similar and the connector loads of C1 and C2 in the X direction are the largest. The oscillation load is observed in the connector in the Y direction at a wave direction of 75° and not at 0°. This paper presents a time domain calculation method of connector load to provide a certain reference function for the future development of Chinese VLFS 相似文献
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In this paper, graphical-user-interface(GUI) software for simulation and fuzzy-logic control of a remotely operated vehicle(ROV) using MATLAB TM GUI Designing Environment is proposed. The proposed ROV’s GUI platform allows the controller such as fuzzy-logic control systems design to be compared with other controllers such as proportional-integral-derivative(PID) and sliding-mode controller(SMC) systematically and interactively. External disturbance such as sea current can be added to improve the modelling in actual underwater environment. The simulated results showed the position responses of the fuzzy-logic control exhibit reasonable performance under the sea current disturbance. 相似文献
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时域仿真分析是获得动力定位控制精度的必要手段。文中进行了SIMO软件理论和应用方面的研究,基于SIMO软件建立动力定位能力时域仿真分析流程;以深水钻井船为算例,通过动力定位系统控制参数和Kalman增益参数的调整,获得较好的计算结果,并进一步分析了控制参数的不同取值对动力定位能力的影响。文中建立的深水钻井船动力定位能力仿真分析流程可以为工程实践提供参考。 相似文献
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《船舶与海洋工程学报》2015,(3)
To simulate the dynamic responses of the multibody system with a floating base when the upper parts spread with a certain sequence and relative speed, the homogeneous matrix method is employed to model and simulate a four-body system with a floating base and the motions are analyzed when the upper parts are spread sequentially or synchronously. The rolling, swaying and heaving temporal variations are obtained when the multibody system is under the conditions of the static water along with the wave loads and the mean wind loads or the single pulse wind loads, respectively. The moment variations of each joint under the single pulse wind load are also gained. The numerical results showed that the swaying of the floating base is almost not influenced by the spreading time or form when the upper parts spread sequentially or synchronously, while the rolling and the heaving mainly depend on the spreading time and forms. The swaying and heaving motions are influenced significantly by the mean wind loads. The single pulse wind load also has influences on the dynamic responses. The torque of joint 3 and joint 4 in the single pulse wind environment may be twice that in the windless environment when the system spreads with 60 s duration. 相似文献
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为了能够快速真实地模拟波浪与张力缆系泊浮体相互作用问题,基于二维边界元格式建立了线性条件下的数值波浪水槽,并以此为基础对张力缆系泊浮体与波浪相互作用问题进行了时域数值模拟。张力缆的作用以系泊刚度的形式表达。与其他学者的相关研究结果对比表明该计算程序是可靠的,该方法可以为相关海洋工程的设计研究提供有利的参考。 相似文献
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深水二维对称式布置两成分锚泊线时域动力分析 总被引:2,自引:0,他引:2
深水作业海上浮式结构物的锚泊定位系统由锚链或锚索等成分进行约束,由于锚泊线的几何非线性,外界环境作用力的非线性和系泊浮体的运动的非线性给锚泊系统的回复力和位移的计算分析带来困难。此外,多种材料成分组成的多成分锚泊线的使用在推动了锚泊系统的深水应用和发展的同时也给锚泊系统的设计带来困难。本文采用设计波理论结合有限元方法进行两成分锚泊线的动力分析,考虑导缆孔处系泊结构物运动的影响。并将结果与单一成分锚泊线计算结果作比较分析,得到有益结论。 相似文献
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《船舶力学》2017,(12)
由于船舶在海上运动的复杂性和非线性,精确的船舶动力定位系统数学模型难以建立。为了实现有效的动力定位控制,需要应用一定的状态估计滤波算法得到所需的船舶运动低频信号。采用常规的Kalman滤波,状态变量的新测量值对预测值的修正作用下降,旧测量值的影响随着计算步数的累积而相对提高,这是引起滤波发散的主要原因之一。文章针对船舶动力定位系统中使用常规的Kalman滤波而存在的模型不精确、不能准确表达系统噪声和测量噪声等问题,采用渐消记忆自适应滤波估算低频运动信息,在状态估计算法中引入渐消记忆因子,减小旧测量值对状态估计值的影响权重,从而增大新测量值的作用;并根据滤波发散判断准则,选择适当的渐消记忆因子值来抑制滤波器的发散,使控制器输出较为平稳,从而降低推力系统不必要的能耗。仿真实验表明,所设计的自适应滤波器的收敛性、跟踪性优于常规的Kalman滤波,有效地提高了系统的定位精度和稳定性。 相似文献