【作者】 倪俊峰；

【导师】 李占利；

【作者基本信息】 西安科技大学 ， 计算机应用技术， 2003， 硕士

【摘要】 在反求工程技术中，物体的测量是反求工程的基础，现有的测量方法和技术很难高精度同时测量物体的内外轮廓。采用层去图象法测量技术可以同时测量零件的内外轮廓特征，得到零件的完整数据模型，精度也较高，而且还有助于缩短产品的设计和生产周期，降低生产成本。为了进一步提高测量精度，本文在对层去图象法反求测量系统中的若干关键技术作了深入研究。 本项目开发研制了一种专用封装材料来封装被测零件，封装材料根据不同的需要，可以配置出不同的颜色，使得与被测零件的图象颜色具有较明显差别，能够提取出精确的零件截面的边界轮廓，并且具有良好的粘合性能、机械性能和适当的韧性，操作也比较简单。 对采集断层图象的摄像系统进行了改良设计，保证了图象的稳定采集。采取了若干措施与方案，对整个测量系统的定位摄像，清除碎屑和图象的拼接等，都实行了自动化测量。并且对从数字图象到零件的层矢量数据整个过程当中涉及到的图象和数据处理算法进行了研究，做出了进一步的改进，并用软件实现了这些算法。 通过对图象中的象素点与空间中的一点之间的映射关系的分析，提出了一种基于网格插值的标定方法，该方法将复杂的非线性的问题转化为一个个小区域的线性问题，实现了图象平面的线性和复杂非线性变形问题的校正。此算法简单快速，能显著地提高了测量系统的精度。 本系统结构简单，设备安装方便，成本低，能够灵活、便利地测量零件内外轮廓特征，在工业快速成型制造领域有着广泛的应用前景。更多还原

【Abstract】 In the reverse engineering techniques, object’s measurement is its foundation. Existing measurement techniques can not obtain the shape data of both exterior and interior surfaces and regions of an object with higher accuracy. Cross-section Imaging Measurement simultaneously digitizes both exterior and interior surfaces of a part, a full data geometry model of a part can be constructed. The technique helps to shorten the design-to-manufacture time and reduce the cost of the product. In order to improve the accuracy further, the paper makes research on the several of critical techniques in the Rapid Reverse Engineering (RRE) system.A kind of special encasing material is developed and used to reinforce the part in the project, which can compound different color according to different requirement .It provides obvious gray scale contrast between the image of part and encasing material and it can obtain the accurate contour of a part’s cross section. This kind of material has good machinability, additives and proper toughness. The whole encasing process is simple and rapid.The paper improves the design of photography system of capturing cross-section image and guarantees the steady capturing of image. It adapts several of measures and projects, which carry out automatic measurement on orientation photography, eliminating crumb, image stitching of entire measure system. Moreover, the paper make research on the arithmetic disposal of image and data in the entire process from digital image to layer vector data of part, and improve it further and realize these arithmetic by soft.Through the analysis of mapping relation between pixel point and a point of space, the paper pose a demarcate method based on grid interpolation. This method transform complicate nonlinear problem to many little regional linear problems and realizeemendation on problems of linear and nonlinear deformation in image. The algorithm is simple and rapid and advance precision of measurement system obviously.The system is of simple configuration and of convenience equipment installation and low cost. It can measure both exterior and interior contour shape of a part conveniently and has abroad applying foreground.更多还原