基于ICT的复杂铸件曲面重构及检测

发布时间：2018-03-27 22:21

本文选题：工业CT　切入点：逆向工程　出处：《哈尔滨理工大学》2017年硕士论文

【摘要】：工业CT(Computerized Tomography)扫描作为一种先进的测量技术,它能够在不损伤零件的情况下以二维断层图像的形式清晰、准确、直观地展示出待测物内外部轮廓形状,这是三坐标测量、激光扫描、逐层切削照相等无法比拟的。本文首先对逆向工程从概念、原理、国内外研究现状、数据的采集技术几个方面作了一个总结性概述,并在此基础上系统地分析了 ICT断层数据预处理、曲面重构、重构模型质量检测等所涉及的关键技术,具体的研究内容如下:1.对铸件的材料、形状进行了详细分析了,结合蔡司1500型工业CT的特性确定了曲面重构的技术路线和工业CT的工作参数,经过扫描生成了代表铸件特性的volume体数据模型,并以STL文件输出。2.将STL格式文件导入Geomagic studio,对导入的数据进行精简、降噪、多边形的修补以及参数化曲面生成一个能够表示零件内外轮廓表面的NURBS曲面,最后将NURBS曲面导入UG中构建了一个可以用于仿制和再设计的实体化模型。3.为了验证重构模型的准确性,将重构曲面模型和原始的扫描模型导入Qualify进行误差分析,通过3D分析、二维截面分析模块分析了重构模型的整体误差和典型截面的误差。结果表明重构模型的整体和典型截面的误差都在合理的范围内。4.铸件在浇铸的过程中易出现夹杂、气孔等缺陷,这些缺陷的存在将直接影响到工件的使用,因此需要对铸件ICT断层数据的典型截面中的气孔的大小、位置以及孔隙率等指数进行分析。结果表明铸件中的孔在合理的范围内,这说明这次铸件的铸造过程是合格的。
[Abstract]:Industrial CT(Computerized Tomography scanning, as an advanced measurement technology, can display the inner and outer contour of the object in a clear, accurate and intuitive form without damaging the parts. This is a three-dimensional measurement, laser scanning. In this paper, the concept, principle, research status at home and abroad, data acquisition technology of reverse engineering are summarized. On this basis, the key technologies of ICT fault data preprocessing, surface reconstruction and reconstruction model quality testing are systematically analyzed. The specific research contents are as follows: 1. The material and shape of castings are analyzed in detail. Combined with the characteristics of Zeiss 1500 industrial CT, the technical route of surface reconstruction and the working parameters of industrial CT are determined. The volume volume data model representing casting characteristics is generated by scanning. The STL format file is imported into Geomagic Studio to simplify, reduce noise, repair polygon and parameterized surface to generate a NURBS surface which can represent the inner and outer surface of the part. In order to verify the accuracy of the reconstruction model, the reconstructed surface model and the original scanning model are imported into Qualify for error analysis. The whole error of the reconstructed model and the error of the typical section are analyzed in the two-dimensional section analysis module. The results show that the errors of the whole and the typical section of the reconstructed model are within a reasonable range of .4.The castings are prone to inclusions in the casting process. The existence of these defects will directly affect the use of the workpiece, so the size of the pore in the typical section of the ICT fault data of the casting is required. The results show that the hole in the casting is within a reasonable range, which indicates that the casting process is qualified.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG247

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