Abstract: Based on the research on STEP and its standard file format, through the text segmentation and parse and the research on the “non-perfect tree typed” structure used in the .stp/.step file, this paper proposes a new STEP 3D instance oriented structured query method on STEP instance data exchanging. Firstly, this paper categories the structured operation granularity, then defines the structured query operation and the rules that each operation should follow, and well realizes this method in lab environment. Through this method proposed, authors look forward to great improvement in 3D data reusing, storage, dynamically exchanging, retrieval and other future development in PDM (product data management), its application in CSCD (computer supported cooperative design) can also improve the consistency, concurrency in heterogeneous CSCD system.

Key words: STEP, STEP instance data, structured query, data exchanging

摘要： 在对三维实体描述STEP标准实例数据格式研究的基础上，以STEP中性文件文本分割和解析为基础，针对STEP标准文件的“不严格树形结构”，实现了一种面向STEP标准三维造型实例数据的结构化查询方法。对STEP标准文件的操作粒度进行划分，面向不同的操作粒度，给出了相关操作规则定义，并在实验环境中得到了较好的实现效果。该方法对解决不依赖具体三维实体设计软件的实例数据的存储、管理、检索、重用及面向STEP中性文件的产品数据管理（product data management，PDM）具有较高的基础性前研意义，对改进异构设计环境下产品数据的同步和协同设计（computer supported cooperative design，CSCD）具有较高的实现意义。

关键词: STEP, STEP实例数据, 结构化查询, 数据交换