组合视觉测量技术应用于大型船舶曲板尺寸检验

针对传统的大型船舶曲板使用固定半径模具进行接触式测量的方法效率低、测量精度低的问题,提出一种基于两套双目视觉测量系统和光学投点器的组合视觉测量方法,在测量区域内布设控制场作为基准,测量过程中移动组合视觉测量系统至不同的位置对大型曲板进行分区域测量,其中一套双目视觉系统对光学投点器投射至曲板上的点进行交会测量,另外一套双目视觉系统测量已知控制点进行数据拼接,可实现对大型船舶曲板外形的高精度、非接触、快速数字化检测,本例中曲板型面拟合得到的RMS值与单目视觉方法得到的曲板RMS值的差值优于0.2 mm,曲版弧长测量误差绝对值小于0.5 mm。且组合视觉的测量方法较为灵活,对曲板尺寸没有限制,适用性好。

基于线激光多目立体视觉的船舶曲板成形在位检测与自动调形系统开发

为实现数控三维弯板机渐进成形船舶曲板的快速、精确在位检测与自动调形,研制了适用于数控三维弯板机加工现场的基于线激光多目立体视觉技术的在位检测与自动调形系统。设计了检测系统方案与结构参数,研究了系统标定、线激光三维重建、点云配准、船板成形偏差与板材回弹量计算等关键技术,开发了基于Windows平台的在位检测与自动调形软件系统。结果表明,该系统测量误差小于±1mm,单次测量时间小于30s,视场大于弯板机加工区域2750mm×2750mm,满足数控三维弯板机加工过程中船板在位检测与自动调形需求。

船舶曲板加工上下料方法研究

经济的高速发展使造船业之间的竞争愈加激烈,近些年智能制造相关技术的发展应用已深入到各行各业。为了提高造船效率、降低造船成本,船厂在生产过程中的很多工序也引入智能制造理念。船舶制造作为典型的离散型制造企业,其传统的船舶制造工装或设备一定程度上限制了新技术新工艺的推广应用。从船舶曲板加工时上下料过程控制钢板吊装、运输的稳定性角度分析,通过对工装、设备的升级和改造,提高现有设备的可操作性和辅助钢板定位精度。

曲板加工点云数据重构和自动调型技术

为实现船舶数控弯板机的智能成型精度检测和自动调型,研制了1套适用于曲板成形精度检测过程的点云数据重构和偏差计算算法,基于B样条曲线对曲板测量点云进行重构和点云加密,实现了测量点云偏差计算和数控弯板机下模压头调形偏差计算,应用到曲板成型精度智能检测系统中,实现曲板成型精度测量和调形数据计算。在某船厂进行曲板成型精度智能检测系统实验,结果表明,测量结果偏差数据分布与样箱测量结果相同,且通过自动调型加工完成的曲板,满足船舶曲板加工过程中的精度要求和效率要求。

A comparative study on the hull strength of a ship with thin-walled box girders

Based on the Finite Element Analysis and Thin Walled-Box girder Mechanics, two design concepts of adding box girders under main deck in order to increase the hull strength of ship are presented. By comparison and analysis on the longitudinal strength, torsion strength and deck buckling between designed concepts and the original concept, it is found that by adding box girders under the main deck, the weight of hull structure is increased by lower than 10%, but the stress on the plate of the main deck is reduced by about 10%, the stress on the plating of the second deck is reduced about 20%. The shear stress on the plating of both of the main deck and second deck is reduced, but the shear stresses in several nodes are increased. Also the capability of resisting damage to ship is obviously increased by adding box girders under the main deck. The deck buckling is also increased by more than 90%. Consequently, the box girders added under the main deck are useful and effective to increase the strength of hull and ship survivability.