Abstract: For alleviating the error-prone and inefficient process of reentering tolerance analysis specification manually and enabling the tolerance analysis system to understand semantics from upstream product design information,an approach interpreting Geometric Dimension & Tolerance (GD&T) semantic information for tolerance analysis was proposed.The GD&T information that needed to be interpreted was categorized,and the neutral-file-based EXPRESS models were developed.The Web Ontology Language (OWL 2) was used to map those EXPRESS models to corresponding ontologies which laid the reasoning foundation;then rules for automatically inferring the tolerance analysis specification were defined and encoded through SWRL.A plug-in for interpreting GD&T semantic information was developed in a CAD system to extract and import interpreted GD&T semantics into neutral files,and protégé was used to model ontology and rules which infered variation for tolerance analysis.A case study of tolerance analysis for an assembly model was also given to demonstrate the proposed method.

Key words: model based definition, tolerance analysis, geometric dimension and tolerance, semantics, ontology modeling, product development

摘要： 为了改善公差分析规范的手工翻译出错率高和效率低的现状,并帮助公差分析系统理解来自上游的产品设计模型的语义信息,提出一种面向公差分析的几何尺寸和公差(GD&T)语义信息翻译方法。对需要翻译的GD&T语义信息进行分类,并建立适用于中性文件的EXPRESS模型;使用本体建模语言将得到的EXPRESS模型映射为对应的本体,为后续的推理提供基础;使用语义网规则语言对从本体中提取公差分析规范的规则进行定义和编码,实现语义信息的自动推理功能;在计算机辅助设计系统上开发了GD&T语义信息翻译插件,自动提取得到的GD&T数据并加入中性文件中,使用Protégé进行本体和规则建模,最终推理出公差分析所需规范。同时使用一个装配模型验证了所提出方法的有效性。

关键词: 基于模型的定义, 公差分析, 几何尺寸和公差, 语义, 本体建模, 产品开发