【作者】 陈磊；

【导师】 叶修梓；

【作者基本信息】 浙江大学 ， 计算机科学与技术， 2008， 博士

【摘要】 随着复杂产品多学科分布式协同设计和管理需求的增长,企业内部和不同企业之间的设计资源重用和设计协作成为现代产品设计发展的趋势。但是,不同设计系统在设计资源知识表示和数据存储上的异构性是阻碍产品设计重用的一个关键问题。论文围绕异构三维CAD模型的产品知识表示和重用问题展开研究,主要工作包括;(1)提出基于本体的产品数据分层表示机制对于异构CAD模型设计重用,产品数据的统一表示是首先要解决的问题。已有产品数据模型缺乏对建模特征、参数、约束和造型历史等CAD高层设计语义的支持,设计人员很难利用现有资源实现产品的变型设计。论文在异构CAD模型基础上提出了产品数据的分层表示机制,并采用本体技术解决了CAD模型的高级设计语义特征、管理数据特征等不同知识的统一表示问题。与已有类似研究比较,我们提出的产品数据模型不但具有良好的可扩展性,而且能有效支持异构CAD系统间各种设计资源的表示和重用。(2)在产品数据分层表示机制的基础上,提出异构三维CAD模型的语义转换方法针对产品数据分层表示机制下的异构三维CAD模型语义层数据转换问题,提出通过语义等价和语义模拟在应用本体和产品数据统一表示本体之间建立映射关系,实现了异构CAD系统间产品模型的语义转换。本文提出的语义转换方法不但保留了原始的建模特征和造型历史,而且支持产品数据的实时转换。(3)面向产品数据分层表示机制提出基于语义知识表示的多层次检索技术对于统一知识表示下的异构CAD模型,如何从已有产品模型中快速查询设计所需的资源,是设计重用要解决的另一关键问题。针对已有实例和语义检索方法难以适用于产品数据分层表示机制下的产品模型检索问题,论文提出集成形状特征和设计知识的多层次语义检索技术。本技术通过形状特征的自动提取捕捉了设计意图,然后通过语义标注在三维产品形状特征和应用特征之间建立映射关系,实现了实例化和语义化两种不同检索方法的统一建模,能够兼顾多种检索需要。(4)提出产品数据分层表示机制下的CAD/PDM集成技术PDM已经成为产品数据存储和管理的重要平台。论文提出在产品数据分层表示下,采用本体实现三维CAD/PDM系统语义集成,解决统一知识表示下的数据存储和管理问题,支持异构系统间对产品知识的共享、重用和交流等。最后,在上述理论框架体系下,通过数字化系统SolidWorks、Inventor、TeamcenterEngeering提供的二次开发接口,实现支持产品设计重用的原型系统。更多还原

【Abstract】 With the increasingly need from multi-disciplinary and distributed collaborative design and data management, reusing and collaboration of design resources within and between companies becomes a trend in concurrent product design. The heterogeneousness of knowledge representation and data storage formats of design resources between different design systems makes it very difficult in product design reuse. This paper probes into product knowledge representation and reuse of heterogeneous CAD models, with its main researches being as follows:(1) An ontology-based hierarchical expression mechanism for product data is proposed.Regarding to design reuse of heterogeneous CAD models, the problem of a uniform representation for product data must be solved urgently. Existing product data models lacked high-level CAD semantics such as modeling features, parameters, constraints, modeling history and etc. This deficiency poses a difficulty for the designers in undertaking product variant design from existing available design resources. In this thesis, a hierarchical representation mechanism for product data based on the CAD feature models is proposed. By adopting the ontology technology, the uniform representation of different knowledge (such as high design semantic features and management data features) of CAD feature models is realized. In comparison with other similar researches, our proposed product data model has an advantage of good expansibility and can support representation and reuse of all kinds of design resources between heterogeneous CAD systems.(2) A method for semantic exchange of heterogeneous 3D CAD feature models is presented based on the hierarchical representation mechanism for product model data.Based on the hierarchical representation mechanism for product model data from heterogeneous 3D CAD features, a method for exchange of product semantics between heterogeneous CAD systems is presented. Using semantic equivalence and simulation, mappings between legacy ontology and uniform representation ontology of product model data are built. The semantic exchange method not only retains its original modeling features and history, but also supports real-time exchange of product model data.(3) A multi-layer retrieval technology based on the semantic knowledge representation is presented under the hierarchical representation mechanism for product model data.Towards the uniform knowledge presentation of heterogeneous CAD models, how to search useful design resources from product models quickly is another key to design reuse. Existing case-based methods and semantics-based methods are hard to be applied to hierarchical representation mechanism for product model retrieval. To solve this problem, this paper proposes a multi-layer semantic retrieval technology integrating form features and design knowledge. The retrieval technology captures design intent using form features that are automatically extracted. By using semantic annotations, the mappings between form features and application features are built, and the uniform modeling of case-based methods and semantic-based methods is realized. So it could meet all kinds of retrieval requirements.(4) A CAD/PDM integration technology is proposed based on the hierarchical representation mechanism for product data.PDM has become an important platform for product data storage and management. Based on the hierarchical representation mechanism, the CAD/PDM semantic integration technology is proposed. The technology can not only resolve problems of data storage and management of the uniform knowledge representation, but also support product knowledge sharing, reuse and communication among heterogeneous systems. Finally, based on above theory framework architecture and application programming interfaces of digital systems, a prototype system for product design reuse is implemented.更多还原