立体标靶辅助多节点三维形貌测量与恢复技术  

Multi-node 3D shape measurement and restoration technology assisted by stereoscopic target

作　　者：王晨 丁宇航 孟召宗 肖艳军[1] 高楠[1] 张宗华[1] WANG Chen;DING Yuhang;MENG Zhaozong;XIAO Yanjun;GAO Nan;ZHANG Zonghua(School of Mechanical Engineering,Hebei University of Technology,Tianjin 300401,China)

机构地区：[1]河北工业大学机械工程学院,天津300401

出　　处：《河北工业大学学报》2023年第5期7-13,38,共8页Journal of Hebei University of Technology

基　　金：重大科学仪器设备开发重点专项(2017YFF0106404);国家自然科学基金(51675160);河北省应用基础研究计划重点基础研究项目(15961701D)。

摘　　要：传统的单节点条纹投影三维测量系统由于相机的视场限制,只能恢复目标有限区域的三维形貌。针对此问题,研究了基于立体标靶的标定技术,并研制了多节点三维测量系统,有效解决物体自身遮挡以及视角有限的问题。多节点测量系统进行实物测量时,各测量节点可恢复不同角度的三维形貌。利用迭代最近点(Iterative Closest Point,ICP)算法对各节点数据进行拼接可获得同一个坐标系中的完整形貌,需要将不同节点间形貌数据的空间关系作为迭代初值,因而对系统内部参数以及各节点间外部参数的标定是测量的必要环节。传统的平面标定板很难同时满足不同视角相机的成像需求,因而本文构建由2个平面组成的立体标靶进行标定,其上均匀分布规格已知的标识点,平面连接处用图案标识,以区分左右面。立体标靶实现了多节点同时标定,改善了视角受限的问题,同时改进了ICP算法以提高选择对应点的容错率。实验结果表明,采用本文所提出的技术,最大测量误差为0.053 mm,可实现被测物多视角的准确测量。The traditional single node fringe projection three-dimensional measurement system can only restore the three-dimensional shape of the limited area of the target due to its limitation of view.To solve this problem,the calibration technology based on stereo target is studied.And a multi-node 3D shape measurement system is developed in this paper to,effectively solve the problem of object self-occlusion and the limitation of view.Each node of the measurement system can restore the 3D shape from different directions.The complete shape in one coordinate system can be obtained by splicing data of each node by using iterative nearest point(ICP)algorithm,and the spatial relationship of data points between different nodes needs to be taken as the iterative initial value,so the calibration of internal parameters of the system and external parameters between nodes is a necessary part of measurement.The traditional plane calibration board is difficult to meet the imaging requirements of cameras with different directions at the same time.Therefore,in this paper a stereoscopic target is set up for calibration,which is composed of two planes,and the identification points with known specifications are uniformly distributed on it.The plane connection is marked with a pattern to distinguish between the left and right sides.The stereoscopic target can solve the problem of view limitation and realize multi-node calibration simultaneously.In addition,the ICP algorithm is modified to improve the fault tolerance rate of selecting corresponding points.The experimental results show that the accurate measurement from multiple directions of the object can be realized by using the technology proposed in this paper,with the maximum measurement error of 0.053 mm.

关 键 词：测试计量仪器 立体标靶 条纹投影 三维测量 数据拼接 

分 类 号：TH741[机械工程—光学工程]