【作者】 张弛；

【导师】 习俊通；

【作者基本信息】 上海交通大学 ， 机械工程， 2020， 硕士

【摘要】 合拢管在船舶管路系统中应用广泛,合拢管测量工程周期长、精度控制差等特点,使得合拢管法兰相对位姿测量成为相关船企希望研究解决的关键性问题。传统合拢管法兰相对位姿测量方法为现场取型法,该方法测量精度低、测量随意性大且存在安全隐患。少数先进船厂采用的基于拉绳传感器的新型接触式测量方法,也因无法适应现场复杂的测量环境而难以广泛应用。本文应用线激光测量与辅助靶标跟踪技术,提出的船舶合拢管法兰相对位姿柔性测量方法,可同时解决以上问题。手持式测量仪中的线激光传感器测量法兰孔孔心坐标,利用测量仪-辅助靶标手眼标定结果和单目相机跟踪的辅助靶标姿态进行两次坐标转换,使测量数据统一在跟踪相机坐标系中,并进一步处理获得法兰相对位姿数据。研究了基于单目视觉的辅助靶标位姿跟踪问题,设计了基于射影不变量进行解码的多面分布式辅助靶标,结合基于轮廓提取的中心定位方法,实现了多角度拍摄不完整标志点情况下的辅助靶标位姿跟踪。分析了法兰线激光图像中各类噪声,从测量姿态优化、自适应阈值算法等方面减小噪声影响,利用改进的灰度重心法和随机抽样一致原理提取了光刀中心数据,提出了基于平面特征点的空间圆拟合方法,提高了孔心定位精度。设计并完成了法兰相对位姿测量实验,结果表明,该方法法兰中心距测量误差0.93mm,法兰平面法向量夹角测量误差0.20°,测量数据满足合拢管设计精度需求。更多还原

【Abstract】 Inserting pipe is widely used in ship piping systems.The characteristics of long construction period and poor precision control of inserting pipe measurement result in measurement of relative pose of inserting pipe flange becoming a key issue that related ship companies hope to solve.Traditionally,the relative pose between flanges of the ship inserting pipe is measured by on-site sampling method,which has low precision,large randomness and hidden safety risks.A new type of contact measurement method based on pull rope sensors adopted by a few advanced shipyards is also difficult to be widely applied because of its inadaptability to the complex measurement environment on site.This paper applies line laser measurement and auxiliary target tracking technology,and proposes a flexible measurement method for the relative pose between flanges of the ship inserting pipe,which can simultaneously solve the problems above.The line laser sensor in the hand-held measuring instrument measures the coordinates of the hole center of the flange hole,and uses the sensor-target Hand-Eye calibration result and the auxiliary target pose tracked by the monocular camera to perform two coordinate transformations,so that the measurement data is unified in the tracking camera coordinate system,and further processed to obtain flange relative pose data.The pose tracking problem of the auxiliary target based on monocular vision is studied.A multifaceted auxiliary target based on projective invariant decoding is designed.Combined with the center positioning method based on contour extraction,the pose tracking of auxiliary target is achieved,where the marks are multi-angle shot and incomplete.Various types of noise in the flange line laser image are analyzed,and the influence of noise is reduced from much aspects such as measurement attitude optimization and adaptive threshold algorithm.The improved center positioning method and the principle of random sampling are used to extract the center data of the light streaks.The method of 3D circle fitting by plane points improves the accuracy of hole center positioning.The relative pose measurement experiment of the flange is designed and completed whose results show that the error of flange center distance measurement is 0.93 mm and the flange plane normal vector angle measurement error is 0.20°,which meets the design accuracy requirements of the inserting pipe.更多还原