Abstract:

The batched complex blanks with same structure and certain deviations in geometry often needed to be reconstructed. The repeated process wasted a lot of labors and extended the production cycle. An efficient reconstruction method was proposed based on the structural template and the reverse design table. Firstly, the feature of the blank's structure was analyzed. A template representing the structure features, as well as a reverse design table based on open knowledge representation, was established. Secondly, the elements in the template and the steps in the design table were utilized to segment the cloud points automatically. Thirdly, different types of surface were reversely reconstructed and post processed orderly. The experimental results validate the method's high efficiency.

Key words: CAD/CAM, batched complex blank, segmentation of point cloud, reverse modeling

摘要：

工程实践中常常需要对结构上相同、几何上彼此有一定偏差的批量复杂结构毛坯逐件进行CAD模型逆向重建，这样重复的操作会浪费大量的人力,制约生产周期。针对此类问题，提出了一种基于结构特征模板和逆向设计表的快速逆向建模方法。该方法首先根据毛坯结构的特点制定结构特征模板、创建基于开放式知识表示的逆向设计表，然后通过读取模板中的元素和设计表中的操作步骤信息自动地依次进行点云测量数据的自动分割、不同曲面类型的逆向重建、各重建曲面特征之间后处理等操作。在算法和理论研究的基础上开发了相关程序，实例验证表明，该方法达到了快速逆向建模的目的。

关键词: CAD/CAM, 批量结构毛坯, 点云分块, 逆向建模