大尺寸工业视觉测量系统  

Industrial vision measuring system for large dimension work-pieces

作　　者：刘建伟[1] 梁晋[1] 梁新合[1] 曹巨明[2] 张德海[1] 

机构地区：[1]西安交通大学机械工程学院,陕西西安710049 [2]西安交通大学电子与信息工程学院,陕西西安710049

出　　处：《光学精密工程》2010年第1期126-134,共9页Optics and Precision Engineering

基　　金：国家863高技术研究发展计划资助项目(No.2007AA04Z124);江苏省科技支撑计划资助项目(No.BE2008058)

摘　　要：针对工业制造领域中大型工件很难进行全尺寸测量的问题,提出并实现了一种基于立体视觉技术的便携式工业测量系统。对该系统所采用的特征识别、相机定向、立体匹配、三维重建、多视点云配准等关键算法进行了研究。提出了改进的CANNY边缘亚像素检测算法,使用先验规则去除误识别的标志点,多次拟合定位标志点中心,对标志点环带多次采样取中值求取编码点的ID。根据ID号找出不同照片中的同名编码点,顺次对照片进行相对定向和绝对定向。然后,根据多幅图像的多极线几何约束,实现非编码点的匹配,消除误匹配。采用前方交会法重建标志点的三维坐标,利用光束平差对计算出的结果和内外部参数做迭代修正。最后,设计了双目结构光扫描系统,提出了一种改进的双目像机标定算法,描述了利用全局和局部标志点的子图同构实现多视点云配准的新算法。实验结果表明,该系统可在生产现场对大型工件进行快速测量,整体测量精度达到0.112mm/3m,可以满足工业现场大尺寸测量对精度和效率的要求。In order to realize the rapid measurement for large dimension work-pieces in industrial fields,a new measuring system based on a stereo vision was proposed and implemented.The key algorithms used in the system,such as feature recognition,camera orientation,stereo matching,object coordinate 3D reconstruction and multi-view point cloud registration,were studied.Firstly,an improved ＇CANNY＇ edge detecting method was presented to achieve the sub-pixel localization,and the experiential knowledge was used to eliminate miss-recognized reference points.By fitting point centers of the position,the ring of the reference points was sampled in multi-time to obtain a median and to constructed its ID.Then,the homonymous coded points in each photo pair were searched according to their unique IDs,and the relative orientation and absolute orientation were carried out.Secondly,the multi-image epipolar constraint method was utilized to implement the un-coded point matching and to remove the mismatching.Furthermore,the 3D coordinates of all reference points were calculated by the spatial intersection,and the interior and exterior parameters,image and object coordinates are corrected by the bundle adjustment synchronously.Finally,a binocular structure-light scanner was constructed to acquire the surface detail information of the work-pieces.An improved camera calibration approach was introduced and its calibration accuracy was compared with those of traditional methods.The multi-view point cloud global registration algorithm was also discussed in detail.Experiment results indicate that the new measuring system is suitable for the large work-piece measurement with an accuracy of 0.112 mm/3 m,and it can satisfy the precision and efficiency demands of the large dimension measurement.

关 键 词：立体视觉 标志点识别 立体匹配 三维重建 点云配准 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置]