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海上浮式结构物运动响应的准确在线预报,对保障海上作业安全具有重要意义.本文基于长短期记忆(LSTM)神经网络模型,建立了浮式海洋平台运动响应极短期在线预报方法,可根据波浪时间序列信息对运动响应进行预报.通过半潜式平台模型试验得到大量波浪序列和运动响应数据,利用这些试验数据建立并训练LSTM模型,并对不同的测试工况进行运动预报和分析.结果表明,所建立的LSTM模型针对浮式海洋平台运动极短期在线预报具有较高的预报精度,预报提前量为12 s时,纵荡、垂荡和纵摇预报精度分别高于90%、93%和85%,且模型的计算效率高,每步计算时间为毫秒级,远小于预报提前时间,可以实现运动在线预报. 相似文献
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在最小二乘方法(RLS,recursive least square)的基础上,提出利用格型递归最小二乘(LRLS,lattice recursive least square)算法对AR模型参数进行自适应估计.该算法为模块式的多极格型结构,降低了一般RLS算法的计算复杂度.利用实测的动态数据结合AIC准则建立自适应AR预报模型,并将该模型应用于船舶运动预报中,仿真结果表明,相对于最小二乘算法,基于LRLS算法的AR预报模型可有效提高船舶运动预报精度. 相似文献
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为了获取海上航行船舶及自航模试验中船模的姿态参数,设计一种基于MEMS(微机电系统)技术的波高倾斜一体化传感器的船舶运动姿态测量系统.此系统通过MEMS波高传感器对船舶升沉信息进行采集,利用倾角传感器对船舶的纵摇和横摇姿态信息进行采集,采集到的信息经多路A/D转换后送入单片机进行处理,实时得出船舶运动的升沉、纵摇及横摇变化.经处理后的三组数据由船舶运动姿态测量系统通过RS-485串口送到数据接收处理机存储、分析并实时显示船舶运动的姿态变化曲线,该数据接收处理软件采用VC++编写.经过大量试验及海上测试,该系统性能稳定,测量精度高,具有较大的实用价值. 相似文献
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针对在改善高速轻型穿浪双体船(WPC)迎浪中波长与船长接近时纵向运动幅度较大的缺点,采用了理论计算与模型试验相结合的方法,对250 t级穿浪双体船开展了水翼改善纵向运动的理论和试验研究,分析了水翼形式、尺度和安装位置等对纵向运动的影响规律。数值计算和试验结果的比较表明,计及水翼—船体水动力干扰影响的切片理论可满足WPC加水翼后波浪中纵向运动计算的需要,但在纵向运动响应峰值处数值计算结果偏高。模型试验表明,250 t级WPC加装水翼后,迎浪纵摇和垂荡有义幅值可减少20%~30%。 相似文献
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In this study, we consider first- and second-order random wave loads and the effects of time-varying displacement volume and transient wave elevation to establish motion equations of the Spar platform’s coupled heave-pitch. We generated random wave loads based on frequency-domain wave load transfer functions and the Joint North Sea Wave Project (JONSWAP) wave spectrum, designed program codes to solve the motion equations, and then simulated the coupled heave-pitch motion responses of the platform in the time domain. We then calculated and compared the motion responses in different sea conditions and separately investigated the effects of second-order random wave loads and transient wave elevation. The results show that the coupled heave-pitch motion responses of the platform are primarily dominated by wave height and the characteristic wave period, the latter of which has a greater impact. Second-order mean wave loads mainly affect the average heave value. The platform’s pitch increases after the second-order low frequency wave loads are taken into account. The platform’s heave is underestimated if the transient wave elevation term in the motion equations is neglected. 相似文献
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LIU Ya-dong LI Ji-de LI ZhenCollege of Shipbuilding Engineering Harbin Engineering University Harbin China 《船舶与海洋工程学报》2002,1(2):6-11
In this paper a 3-D panoramic simulation system of a ship is described which is developed with the MAXSCRTPT language and VC + + as programming tools on the platform of 3 Dsmax. The strip theory method is applied to the motion prediction of the mono-hull. The time history solutions of heave and pitch are obtained in the condition of head sea to provide the primary data on panoramic simulation. The simulation system has following functions: 1) digital simulation; 2 ) panoramic simulation; 3) environmental set-up; 4) render preview and output. 相似文献
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《船舶与海洋工程学报》2016,(2)
In this study, the coupled heave-pitch motion equations of a spar platform were established by considering 1st-order and 2nd-order random wave loads and the effects of time-varying displacement volume and transient wave elevation. We generated random wave loads based on frequency-domain wave load transfer functions and the Joint North Sea Wave Project(JONSWAP) wave spectrum, designed program codes to solve the motion equations, and then simulated the coupled heave-pitch motion responses of the platform in the time domain. We then calculated and compared the motion responses in different sea conditions and separately investigated the effects of 2nd-order random wave loads and transient wave elevation. The results show that the coupled heave-pitch motion responses of the platform are primarily dominated by wave height and the characteristic wave period, the latter of which has a greater impact. 2nd-order mean wave loads mainly affect the average heave value. The platform's pitch increases after the 2nd-order low frequency wave loads are taken into account. The platform's heave is underestimated if the transient wave elevation term in the motion equations is neglected. 相似文献
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基于MIKE 21 Mooring Analysis系泊分析软件,模拟研究在不同周期和入射角度的不规则波作用下系泊船舶运动的变化规律。结果表明,系泊船舶运动量随波浪入射角度和波浪周期的变化相互影响。在不同周期波浪作用下的系泊船横移、横摇和升沉运动量均随波浪入射角度的增大而增大,横摇运动的共振效果随着波浪入射角度远离90°方向逐渐减弱,升沉运动量在波浪入射角度靠近90°或0°方向时基本不变。当入射波浪周期较长时,纵移和回转运动量随着波浪入射角度的增大先增大后减小,一般在波浪60°入射时产生峰值。 相似文献
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船舶在波浪中的响应一直被船舶工程师广泛关注。本文以Wigley船为对象,采用线性回归计算船舶在规则波中运动的附加质量,采用刘易斯法计算阻尼系数。以新切片理论为基础建立和求解频域内的垂荡和纵摇的耦合运动方程,得到船舶在频域中的运动响应和波浪载荷,并与三维网格法的计算结果进行比较,表明这是一种可靠的、简单快捷的计算船舶在波浪中响应的方法。 相似文献
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Binbin Li Zhenhua Huang Ying Min Low Jinping Ou 《Journal of Marine Science and Technology》2013,18(2):229-246
The heave motion of a floating structure is critical, as a favorable heave characteristic permits dry tree systems, amongst other benefits. The heave response can be suppressed by installing heave plates. However, the associated hydrodynamic effects, which include viscous damping and added mass, are very complicated. Moreover, there are limited experimental investigations to understand the heave plate effects on actual platform designs. This paper aims to study the abovementioned issue based on a novel deep draft multi-spar (DDMS) platform, for four different configurations (with/without upper and lower heave plates). A set of experiments (free decay, regular and irregular wave tests) are conducted, and compared with time domain and linearized frequency domain analyses. Amongst other things, the investigations and discussions include the added mass and damping coefficients for the platform and heave plates, comparison of experimental and numerical results, and the influence of the heave plates on the surge, heave and pitch motions. 相似文献