【作者】 张伟；

【导师】 陈蔚芳； 薛建彬；

【作者基本信息】 南京航空航天大学 ， 机械电子工程， 2006， 硕士

【摘要】 随着CAD、CAPP以及CAM在制造业中的广泛运用,在这三个系统之间实现信息的集成和共享,已经成为一个迫切需要解决的问题。解决这个问题的关键就是建立一个能在系统间共享信息的产品模型。面向特征的建模技术以及产品数据交换标准STEP的出现为建立这样一种模型提供了一种可行的方法。本文首先介绍了当前现有的产品数据模型,包括线框、曲面、实体和特征模型,及相关的产品数据交换标准,包括IGES、PDES、PDDI和STEP,分析了它们各自的特点和不足之处。针对现有数据模型在材料、公差以及工艺信息等方面的缺失,研究了在基于STEP的面向特征的产品数据模型中集成这些信息的方法,建立了一些常见特征,如孔类、平面、外圆、平面槽及旋转槽、圆周阵列、矩形阵列等特征的信息模型,并用EXPRESS语言来表达,该模型不仅包含几何拓扑信息,而且增加了公差、工艺路线、装夹定位、加工方法、及材料等信息。最后在Visual C++的平台上开发了一个能扩充Pro/E生成的STEP中性文件的数据集成系统,通过该系统能生成一个扩展的STEP产品数据模型,并能方便地生成一个可行的工艺规程,从而实现CAD/CAPP的无缝集成。更多还原

【Abstract】 With the wide use of CAD CAPP and CAM systems in manufacturing industry, it becomes a problem to be solved imminently to integrate and share the information among the three systems. To solve the problem, there are two main tasks: one is to create a product model, another is to define a product data exchange standard. The product model should contain the information that needed during the integration of CAD CAPP and CAM, and the product data exchange standard ensure the information share among CAD CAPP and CAM systems. The combination of the feature based technology and the new product data exchange standard, so called STEP, provides a feasible method to create such a model.First, the author introduces some present product data models including wire frame model, surface model, solid model, and feature model, and some related product data exchange standards including IGES, PDDI, PDES, and STEP. The characteristics and shortages of the product data models and the product data exchange standards are analyzed in general. Aiming at the shortage of material information, tolerance information, technical information, and so on in the model, the author conducted a research on a STEP based and feature oriented method to integrate the information in the model. The models for several common features were created. They are hole feature, planar face feature, outer-round feature, planar pocket feature, revolved groove feature, circular pattern feature, and rectangular pattern feature. The paper also uses STEP standard to express information of some familiar features just as hole feature, planar face feature and so on. These models are all expressed in EXPRESS language. These models consist of geometric information, tolerance information, process routing information, fixture and jig, tooling method, and material information. At last, the author developed a proto type system, which can extend the Pro/E generated neural STEP file through adding the additional information such as tolerance, process routing, and so on. The extended STEP model can automatically generate a feasible process plan to realize the seamless integration of CAD/CAPP.更多还原