介观尺度零件变视场结构光显微立体视觉测量方法研究

发布时间：2018-04-13 22:27

本文选题：介观尺度 + 结构光显微立体视觉　；参考：《上海交通大学》2015年博士论文

【摘要】：微系统技术的发展对尺寸范围在0.1mm~10mm的介观尺度零件的有效测试提出了日益迫切的需求。介观尺度零件由于其尺寸小、易集成、能耗低、成本低等优点,在国防工业、航空航天、微电子、生物医学等多个领域都有广泛的应用及前景。目前在工业生产中广泛采用的微型测试技术主要是用于检测二维和准三维的微型零件,无法直接用于有效检测具有复杂形面的介观尺度零件。现有介观尺度零件的测试水平和测试装备与介观尺度复杂形面零件测试需求之间的矛盾逐渐凸现,成为制约微系统技术快速发展的瓶颈。本论文针对介观尺度零件个体尺寸差异较大的特点,提出了基于大倍率变焦双远心投影镜头与远心立体视觉相结合的结构光显微立体视觉测量方法。首先,针对现有投影光学系统在介观尺度存在的变焦能力有限、非物方远心等问题,研究了适用于介观尺度的大倍率变焦物像双远心投影系统的设计方法。近轴设计方面,现有的设计方法主要停留在小倍率变焦设计,而且当放大倍率经过m=-1时存在奇值。对此,首先针对三镜组结构的双远心变焦镜头进行了近轴设计,对系统特性进行了详细的分析,并且对三镜组结构的双远心变焦系统作了详细的分类。针对三镜组结构系统在物像共轭的情况下较难实现大倍率变焦的情况,提出了四镜组结构的物像共轭双远心变焦系统的近轴设计方法。将四镜组结构双远心变焦系统分为6类。对于每一类结构,都给出了其详细的数学模型和近轴设计方法。像差设计方面,对现有的像差设计方法作了改进,将全部三阶像差都引入到设计模型之中。提出了像差变化的概念,包括中心拉格朗日变化,中心物像共轭变化,以及中心光阑变化,并推导了相应的像差变化公式。提出了薄透镜模型设计方法,厚透镜模型设计方法,以及混合模型设计方法。基于以上研究成果,完成了双远心变焦镜头的设计。公差分析以后,设计加工了镜组机械结构部分,最终对镜组进行了装调检测。最后,针对基于远心镜头的结构光双目立体视觉展开研究。首先给出了远心镜头成像的数学模型。在远心镜头标定方面,改进了基于二维靶标的标定算法,并且提出了基于三维靶标的标定算法以及远心立体视觉图像矫正算法,包括畸变图像矫正算法以及行对齐矫正算法。对尺寸范围为0.5mm至5mm的零件进行了三维测量,获取了被测物体大密度的三维点云数据。在此基础上进行了精度验证,实验发现其可以达到微米的测量精度,表明本文方案适用于介观尺度零件的三维测量。
[Abstract]:The development of microsystem technology has put forward an increasingly urgent need for the effective measurement of mesoscopic parts in 0.1mm~10mm.Due to its advantages of small size, easy integration, low energy consumption and low cost, mesoscopic parts have been widely used in many fields such as national defense industry, aerospace, microelectronics, biomedicine and so on.At present, the micro-test technology widely used in industrial production is mainly used to detect two-dimensional and quasi-three-dimensional micro-parts, which can not be directly used to effectively detect mesoscale parts with complex surface.The testing level of mesoscopic parts and the contradiction between the testing equipment and the testing requirements of mesoscopic complex shape surface parts have gradually emerged, which has become the bottleneck restricting the rapid development of microsystem technology.In this paper, aiming at the large difference in individual size of mesoscopic parts, a new method of structural light microscopy stereo vision measurement based on large magnification zoom double telecentric projection lens and telecentric stereo vision is proposed.Firstly, aiming at the problems such as the limited zoom ability of the existing projective optical system at mesoscopic scale and the non-metacentric projection system, the design method of the bitelecentric projection system with large magnification for mesoscopic scale is studied.In the near axis design, the existing design methods mainly stay in the small magnification zoom design, and there is an odd value when the magnifying ratio passes through mg-1.In this paper, the paraxial design of the double telecentric zoom lens with the three-mirror structure is carried out, and the characteristics of the system are analyzed in detail, and the double-telecentric zoom system with the three-mirror structure is classified in detail.In order to solve the problem that it is difficult to realize large magnification zoom in the case of image conjugation, a design method of the image conjugate double telecentric zoom system with four-mirror structure is presented in this paper.The double telecentric zoom system with four-mirror structure is divided into six categories.For each kind of structure, its detailed mathematical model and paraxial design method are given.In the aspect of aberration design, the existing aberration design methods are improved and all third-order aberrations are introduced into the design model.The concept of aberration variation is proposed, including the central Lagrange variation, the conjugate change of the central object image and the variation of the central aperture, and the corresponding aberration variation formula is derived.The thin lens model design method, thick lens model design method and hybrid model design method are proposed.Based on the above research results, the design of double telecentric zoom lens is completed.After tolerance analysis, the mechanical structure of mirror group is designed and machined.Finally, the structure light binocular stereo vision based on telecentric lens is studied.First, the mathematical model of telecentric lens imaging is given.In the aspect of telecentric lens calibration, the calibration algorithm based on two-dimensional target is improved, and the calibration algorithm based on three-dimensional target and the correction algorithm of remote stereo vision image are proposed, including distortion image correction algorithm and line alignment correction algorithm.The 3D point cloud data of the measured objects with large density are obtained by measuring the parts with the size range from 0.5mm to 5mm.On the basis of this, the accuracy is verified, and the experimental results show that the proposed scheme can achieve the measurement accuracy of micron, which indicates that the proposed scheme is suitable for the three-dimensional measurement of mesoscopic parts.
【学位授予单位】：上海交通大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TG806;TP391.41

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