利用用户定义特征实现基于约束设计

提出了基于约束的用户定义特征（User Defined Feature,UDF)定义与比实例化的通用机制及基于约束的特征库管理，并应用于国产CAD／CAM软件金银花（Lonicera)系统，以航空发动机转子为例，建立了转子特征库，对系统功能进行了验证。该项工作既为详细设计阶段考虑装约束和制造约束提供了方便，提高了设计效率，也为将用户定义特征与产品功能相联系、以支持计算机辅助概念设计打下了基础。

A Constraint Based CAD System Using User Defined Features

A constraint based generic mechanism is proposed for defining and instancing user defined features, which are managed by constraint based library functions to realize feature based design paradigm. This mechanism not only speeds up the design process and facilitates the representation of assembly constraints and manufacturing constraints in and among user defined features in detail design phase, but also lays foundation to binding user defined features with function elements of product, thus supporting computer aided conceptual design and establishing integrated product model based on user defined features. The mechanism is realized on Lonicera, a self\|developed CAD/CAM integrated system and a case study of aeroengine rotor design is illustrated.