基于本体的产品知识表达和检索技术研究

针对产品知识的表达、重用、共享和交流等问题，整合三维模型内容与产品设计领域的知识，提出了一个由元数据层、本体层和应用层3层构成的分层产品知识管理框架.元数据层自动从产品模型数据交换标准(standard for the exchange of product model data，STEP)文件中提取数据，并提供对产品数据的精确导航.基于产品分层模型的本体层以一种通用的形式化方式表达了丰富的产品数据.应用层的检索机制，结合形状特征的自动提取和语义注释商法，在产品特征和本体概念间形成映射，弥合了基于实例方法和基于语义方法之间的鸿沟.原型系统的开发和实验结果证明了框架的有效性和可行性.

Ontology-based product knowledge representation and retrieval

A hierarchical framework for product knowledge management was presented to represent,reuse,share and exchange product knowledge.Integrating the contents in 3D models and product design knowledge,the framework is divided into three levels: metadata layer,ontology layer and application layer.Data in the metadata layer is automatically extracted from standard for the exchange of product model data(STEP) files.The metadata layer is used to precisely navigate for product data.Based on a layered product model,the ontology layer is constructed to represent product data in a general and uniform way.By mapping between form-features extracted from 3D models and ontology concepts,a new retrieval mechanism on the application layer bridgeds the gap between semantic-based approaches and case-based approaches.A prototype system was implemented to demonstrate the feasibility and effectivity of the advanced methodology.