基于DAG表示与产生式的IGES装配体数据交换算法

摘要

The Initial Graphics Exchange Specification (IGES) is one of the most widely used neutral file standards. The related researches have mainly focused on the translation of single parts, however, few of them dealt with the IGES form for assemblies, which appear frequently in design. In this paper, we first summarize the IGES-file form of assemblies in most popular CAD software and then propose an IGES data exchange algorithm for assemblies based on Directed Acyclic Graph (DAG) Representation and Production Rules. This method standardizes the process of analysis of IGES forms, which enhances its commonality and extensibility. Moreover, the correctness of the method can be formally verified. With this method, we implement the pre-processor and post-processor for the multi-file IGES representation for assemblies. The experiments conducted in our geometry modeling system TiGems 7.0 show that the algorithm is fast and robust.%初始图形交换规范( IGES)是目前应用最为广泛的中性文件格式标准之一,但是相关的研究主要集中在单零件的格式转换上面,对设计中经常用到的装配体的IGES格式研究较少.该文总结了常用CAD软件中装配体导出的IGES文件存储格式,提出并实现了一种基于图表示与产生式规则的IGES装配体数据交换算法,将IGES格式的解析过程标准化,使其具有通用性和可扩展性,并且正确性可以进行形式化验证.应用该方法,该文具体实现了多文件格式的装配体IGES前置和后置处理器.在几何造型系统TiGems7.0中进行的实验结果表明该算法具有较快的速度,也具有较好的鲁棒性.