现代产品几何技术规范(GPS)的数字化理论基础

DIGITIZED THEORETICAL FOUNDATION OF NEW GENERATION GEOMETRICAL PRODUCT SPECIFICATION AND VERIFICATION (GPS)

现代产品几何技术规范 (generationgeometricalproductspecificationandverification ,GPS)是ISO TC2 13针对产品的设计与制造而规定的一系列宏观和微观的几何技术规范 ,它包括产品的规范过程、生产过程、认证 (检验 )过程以及不确定度的评定和控制。表面模型是ISO TC2 13GPS语言中新提出概念 ,它是实现GPS系统阶段功能的操作基础和系统关联基础 ,表面模型需要由相应的“要素”和“特征”予以定义和描述。ISO TC2 13GPS将工件 要素分为七种恒定类 ,所有的理想要素都属于七种恒定类中的一种 ,且可由其位置要素和本质特征进行定义与描述 ;位置特征则定义了要素之间的关系。第二代GPS系统通过表面模型、恒定类、恒定度、特征等概念的引入和互补应用 ,实现了几何要素从定义、描述、规范到实际检验评定过程中数字化控制功能的飞跃 ,比较有效地解决了产品在“功能描述、规范设计、检验评定”过程中数学表达统一规范的难题。

New generation geometrical product specification and verification(GPS)is a series of macro and micro geometrical specification regarding the design and manufacture, which was developed by the International Standards Organization Technical Committee 213.It includes specification process, production process, verification process and the evaluation and control of uncertainty. Surface model is the new concept in ISO/TC213 GPS, It is the operation basis and system related basis in realizing GPS stage function. Surface model need be defined and described by “feature' and “characteristics'.ISO/TC213 GPS divides workpieces/features into seven kinds of invariance class, all ideal features belong to one of the seven invariance classes and can be defined by its situation features and its intrinsic characteristics, situation features and intrinsic characteristics. The situation characteristics define the relative situation between two situation features. So, new generation GPS system, through introduction and application in such concepts as surface model, invariance class, invariance degree, characteristic,etc. The digitized control function of the feature's definition, description, specification and verification was realized, and the problem of unified mathematics expression in the course of “function description, specification and verification' was resolved more effectively.