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1、摘 要硕士学位论文焊接失稳变形光学非接触三维检测的研究Research on Three-dimensional Optical Discontiguous Measuring Technology for Thin-Sheet Metal Buckling Distortion due to Weld摘 要在轮船、汽车、航空航天等领域越来越多的应用高强度薄壁金属，因其具有减轻结构重量，提升动力，节省能源等优点。但是由于薄壁金属焊接结构的特点，在焊接过程中容易产生失稳变形，即薄壁结构在焊接残余压应力的作用下在刚性较小的结构，纵向压应力超过临界失稳应力造成局部失稳而引起的波浪形变形。这将严重影响
2、焊接构件的质量，给产品带来安全隐患。而传统测量手段的不足无法准确测量焊接过程中的位移变形和应变，因此无法准确掌握焊接变形规律。针对这类问题的研究无疑会对制造行业和相关学科研究具有重要的理论意义和工程应用价值。对光学非接触方法中的一些关键技术问题进行了研究，开发出三种完整的测量焊接失稳变形的检测手段，能够针对焊接变形进行表面关键点静态检测，表面轮廓全局静态检测，表面全场动态应变变形检测。主要研究工作的内容和所获成果有：（1） 提出一种焊接失稳变形关键点比对测量手段。对基于工业近景摄影测量系统的静态变形系统进行了理论研究，改进搜索匹配算法提出了深度搜素算法，能够使得标志点的粘贴不再限制于变形量，能
3、够针对薄板表面关键点进行变形测量。使用静态变形系统进行焊接失稳变形测量实验。（2） 提出一种焊接变形三维轮廓点云比对测量手段。对三维光学面扫描技术和点云融合进行理论研究，提出基于约束搜索球的点云与CAD模型比对算法，能够将焊接变形前后薄板表面的点云经过数据处理进行比对分析，从而得到失稳变形量。使用三维光学面扫描和点云比对软件进行焊接失稳变形测量实验。（3） 提出一种焊接失稳变形全场动态应变测量手段。对基于图像相关法和双目立体视觉技术的三维数字散斑动态应变测量系统进行研究，提出基于种子点的散斑图像匹配算法，提高图像匹配精度。使用三维数字散斑系统对焊接失稳变形进行300mm200mm和64mm48
4、mm两个幅面的测量实验。关 键 词：焊接失稳变形；光学非接触；静态变形；点云比对；数字散斑论文类型：应用研究IABSTRACTTitle: Research on Three-dimensional Optical Discontiguous Measurement Technology for Thin-Sheet Metal Buckling Distortion due to WeldSpeciality:Mechanical EngineeringABSTRACTWith the development of ship, automobile, aerospace and other
5、equipment manufacturing industry, thin-sheet metal are widely for the sake of low weight, energy saving and power improving. Because of the distructure characteristics, thin-sheet metal occur the buckling distortion, that will seriously damage the quality of the weld components. The traditonal conta
6、ct measurement cannot satisfy the accurate measurement of the buckling distortion, so the distortion discipline cannot be grasped correctly. It is valueble to study this kind of problem for manufacturing industry and interrelated subjects both in theory and in application meaning.The key technology
7、of optical discontiguous is studied, and 3 methods for the measurement of welding buckling distortion are developed, including the key points static measurement, the full-field static measurement and the full-field dynamic measurement. The main contents and achievements are listed as follows:1.A sch
8、eme for welding buckling distortion by key points compare measurement method is proposed. Study on the theory of static deformation measureent system which is based on the Close-Range Photogrammetry. A scheme for Depth Search Algorithm to make the space between uncoded points have no relatetionship
9、with the distortions and can be applied to the measurement of the key points on the surface of sheet metal. Measure the welding buckling distortion with XJTUSD.2.Propose a welding buckling distortion measurement method by the comparison of three-dimensional point-clouds. Study on the theory of three
10、-dimensional optical scanning and the point-clouds syncretic, propose a novel inspection method based on searching sphere to acquire the distortion by the compare of the point-clouds and the CAD model. Measure the welding buckling distortion with the XJTUOM and XJTUOM INSPECTOR3.Propose a full-field
11、 dynamic welding buckling distortion measurement method based on the digital image correlation and binocular stereovision. Measure the welding buckling distortion the with the XJTUDIC under the 300mm200mm and 64mm48mm measurement area.KEY WORDS: Buckling Distortion; Optical Discontiguous Measurement
12、; Full-field Dynamic Strain Measurement; Key Points Static Measurement; Point-clouds and CAD model ComparisonTYPE OF THESIS: Applied ResearchIII目 录绪论目 录1 绪论11.1 引言11.2 焊接失稳变形光学非接触检测21.2.1 研究背景21.2.2 国内外发展现状31.3 课题来源与研究意义41.3.1 课题来源41.3.2 研究意义41.4 主要研究内容和技术路线51.4.1 研究内容51.4.2 技术路线52 焊接失稳变形关键点变形比对测量技术
13、研究72.1 引言72.2 静态变形测量技术72.2.1 相对定向72.2.2 空间后方交会82.2.3 空间前方交会82.2.4 光束平差92.2.5 坐标配准102.2.6 相同变形点匹配122.2.7 静态变形测量系统实验方案122.3 深度搜索算法142.4 实验验证162.4.1 实验参数162.4.2 实验设备172.4.3 实验过程182.4.4 实验结果212.5 本章小结233 焊接变形三维轮廓点云比对研究243.1 引言243.2 三维光学面扫描技术243.3 基于约束搜索球的点云与CAD模型比对分析方法253.4 实验验证273.4.1 实验参数273.4.2 实验设备2
14、73.4.3 实验过程283.4.4 实验结果303.5 本章小结334 焊接变形全场动态应变测量研究344.1 引言344.2 数字图像相关法344.3 双目立体视觉364.4 立体匹配364.5 种子点匹配算法384.6 实验设备394.7 400mm300mm幅面实验验证404.7.1 实验参数404.7.2 实验过程404.7.3 实验结果424.8 64mm48mm幅面实验验证464.8.1 实验参数464.8.2 实验过程474.8.3 实验结果484.9 测量方法综合比较514.10 本章小结525 结论与展望535.1 结论535.2 展望53致 谢55参考文献56声明61CO
15、NTENTS绪论CONTENTS1 Preface11.1 Foreword11.2 Discontiguous Optical Measurement on Sheet Metal Welding Buckling Distortion21.2.1 Research Background21.2.2 Research Development at Home and Abroad31.3 Subject Source and Research Significance41.3.1 Subject Source41.3.2 Research Significance41.4 Research Content and Technology Route51.4.1 Research Content51.4.2 Technology Route52 Key Points Comparison Method on Sheet Metal Welding Buckling Distortion72.1 Foreword72.2 Static Deformati
