毕业论文-基于COMET系统的CAD建模与应用研究.doc

基于Comet系统的CAD建模与应用研究 Based On The COMET System And Application Of CAD Model摘 要 随着计算机图形学、计算机辅助几何设计和高性能计算等相关技术的发展，三维CAD技术己在制造业中被广泛使用，产品的三维CAD模型己成为现代产品开发、制造、改型和使用维护的基础和平台。因此，获取产品的三维CAD模型有着非常重要的意义。在没有产品以D模型和没有设计图纸或者设计图纸不完整的情况下，按照现有产品样件，利用各种数字化技术及以D技术重构其CAD模型的过程，被称为实物反求工程。 本文对曲线、曲面重构的基本理论进行了论述。介绍了曲线、曲面的数学模型，以及插入和逼近两种数据重构方法，并研究了曲面重构的具体方法过程。提出了由点云直接够建曲面和由特征曲线构建曲面的方法。研究和讨论了曲面光顺准则以及分析方法，如等曲率线法、反射线法、高亮度线法和等照度线法。 关键词：逆向工程 光学测量 COMETCAD 模型重构Abstract Along with the computer graphics, computer aided geometric design and high performance computing technology development, the d CAD technology in manufacturing, products are widely used in d CAD model has become a modern product development, manufacture, use and maintenance of the impellers based platforms. Therefore, the d CAD model for product has a very important significance. In no products to D model and no blueprints or design drawings under the condition of incomplete, according to the existing product sample, use all sorts of digital technology and the technical reconstruction in D CAD models, called the physical process of reverse engineering. This paper curve and surface reconstruction of basic theory are discussed in this paper. Introduces the mathematical model of the curves and surfaces, and insert and approximate two data reconstruction method, and the specific methods of surface reconstruction process. Put forward by point cloud is built by direct curved surface and curve surface construction. The research and discussion and analysis of surface standard methods, such as such curvature line method, rotating polygon.some basic method, high brightness line method and the method of illuminationetc. Keywords: Reverse Engineering Optical Measurement The COMET CAD Model Reconstruction 目 录 第一章 绪 论 1 1.1引言 1 1.2逆向工程的概念和应用 2 1.3数据获取 3 1.4测点数据预处理和曲面建模 3 第二章 基于COMET光学测量系统的数据获取 5 2.1测量方法的比较 5 2.2COMET IV测量系统原理 7 2.3COMET IV系统的测量方法 8 第三章 点云数据的处理 11 3.1引言 11 3.2多视点云的对齐与融合 12 3.3点云的多边形化 16 3.4点云数据的平滑 17 3.5点云数据精