基于STEP的产品数据表示和交换的研究

本文介绍了ＳＴＥＰ标准的概念和原理，基于ＳＴＥＰ标准对各种计算机辅助系统进行集成的策略，以及ＳＴＥＰ模型描述语言ＥＸＰＲＥＳＳ的编译器的实现和ＧＨＭｏｄｅｌｉｎｇ４．０的ＳＴＥＰ中性文件前后处理器的实现，语言轩讨论了ＳＴＥＰ标准的实现原理、ＥＸＰＲＥＳＳ编译器的作用、ＳＤＡＩ数据字典结构、ＳＴＥＰ中性文件的前后处理过程和应用协议在产品数据交换中的应用。     

A STEP-BASED CAD/CAPP INTEGRATION

ＡＳＴＥＰ－ＢＡＳＥＤＣＡＤＩＣＡＰＰＩＮＴＥＧＲＡＴＩＯＮＺｈｅｎｇＬｉａｎｙｕ；ＤｕＰｅｉＡＳＴＥＰ－ＢＡＳＥＤＣＡＤＩＣＡＰＰＩＮＴＥＧＲＡＴＩＯＮ￥ＺｈｅｎｇＬｉａｎｙｕ；ＤｕＰｅｉＡｂｓｔｒａｃｔＴｈｅｉｎｆｏｒｍａｔｉｏｎｉｎｔｅｇｒａｔ...     

GHCAD：一个产品模型为基础的CAD／CAM集成系统

ＳＴＥＰ是关于产品数据表达和交换的国际标准，如何将ＳＴＥＰ的方法和规范应用于系统开发是解决计算机集成制造系统（ＣＩＭＳ）开发的关键问题之一。集成化ＣＡＤ／ＣＡＭ系统是ＣＩＭＳ的核心，实现将ＣＡＤ的工程设计功能和ＣＡＭ的制造功能的结合。本文介绍一个产品模型为基础的ＣＡＤ／ＣＡＭ集成系统－ＧＨＣＡＤ。系统采用ＳＴＥＰ的数据交换、建模思想，以产品模型为核心，通过ＳＴＥＰ的标准数据接口ＳＤＡＩ实现了系统的集成。     

STEP标准的分类与现状

ＳＴＥＰ标准是一个用于计算机可解释的产品数据表达与交换的重要国际标准。在工业界，ＳＴＥＰ标准正受到越来越多的重视。本文试图从构成与分类方面给ＳＴＥＰ标准及其在我国国家标准中的引用民政部一个较全面的介绍，以期对有关科技人员了解ＳＡＴＥＰ、和民帮助。     

利用PDES／STEP实现CAD／CAM信息集成

本文介绍了新一代基于产品数据的数据交换标准ＰＤＥＳ／ＳＴＥＰ的结构和特点，并提出了将基于特征的造型系统所建立的产品信息模型运用ＰＤＥＳ／ＳＴＥＰ来表示，从而实现ＣＡＤ／ＣＡＭ信息集成系统中数据交换和共享的方法。     

基于STEP标准的应用系统接口的开发

ＳＴＥＰ标准是一套关于产品的整个生命周期内的产品数据的表达与交换的国际标准，本文首先介绍了国外最新的ＳＴＥＰ标准的应用动态和ＳＴＥＰ软件工具Ｃａｓｅｌｉｂ，然后从ＳＴＥＰ标准的中性机制谈到如何利用ＳＴＥＰ工具开发ＳＴＥＰ标准应用系统。     

基于STEP的曲线曲面造型技术

ＳＴＥＰ做为新一代的产品数据交换标准，正在被越多越多的ＣＩＭＳ系统所青睐，本文介绍了ＳＴＥＰ的特点，特别是对ＳＴＥＰ中作为曲线面造型系统设计基础的几何与拓扑集成资源做了较深入的解剖和分析，并在此基础上提出了一个基于ＳＴＥＰ的曲线曲面造型系统ＡＤＤＳＳ。     

STEP信息集成软件工具的设计和实现

ＳＴＥＰ是国际标准化组织ＩＳＯ正在组织开发的应用于计算机集成制造系统（ＣＩＭＳ）信息集成的产品数据表达与交换标准，ＳＴＥＰ不仅是一种规范，更是一种信息集成技术，本文以ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统集成为背景，提出了ＳＴＥＰ信息集成支持工具ＥｘＴｒａ的设计和实现技术，该软件工具已成功且有效地应用于ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统集成中。     

升技“雪精灵”ST6E主板

时至盛夏,升技电脑更为玩家考虑,推出采用乳白色ＰＣＢ板的ＳＴ６Ｅ主板,给炎炎夏日带来丝丝清凉。升技“雪精灵”ＳＴ６Ｅ采用Ｉｎｔｅｌ ８１５Ｅ Ｂ－Ｓｔｅｐ（ＩＣＨ２）芯片组,整合ＩＮＴＥＬ ３Ｄ图片加速功能。不仅全面支持现有的ＩＮＴＥＬ ＦＣ—ＰＧＡ架构的ＰⅢ或Ｃｅｌｅｏｎ（赛扬）ＣＰＵ,更可支持未来Ｉｎｔｅｌ推出的ＦＣ－ＰＧＡ２架构的ＣＰＵ,做到全面兼容！ 升技 ＳＴ６Ｅ主板支持ＡＩＭＭ（ＡＧＰ Ｉｎ—ｌｉｎｅ Ｍｅｍ－ ｏｒｙ Ｍｏｄｕｌｅ）, ３根ＤＩＭＭ插槽最高可支持 ５１２ＭＢ的ＳＤＲＡＭ,并集成…     

基于STEP的曲线曲面造型技术

ＳＴＥＰ做为新一代的产品数据交换标准，正在被越来越多的ＣＩＭＳ系统所青睐，本文介绍了ＳＴＥＰ的特点，特别是对ＳＴＥＰ中做为曲线曲面造型系统设计基础的几何与拓扑集成资源作了较深入的解剖和分析，并在此基础上提出了一个基于ＳＴＥＰ的曲线曲面造型系统ＡＤＤＳＳ。     

在CIMS中支持STEP应用协议的研究与实现

讨论了ＳＴＥＰ中性文件和数据库两种数据交换技术,给出了从ＧＳ－ＣＣＣ的全局产品数据结构到ＳＴＥＰＰａｒｔ２０３结构模型映射。     

Pro/E和UG之间三维模型数据交换方法

为了实现CAD系统（Pro/E）和CAM系统（UG）之间三维实体模型数据交换,以卫星零部件为对象,根据系统之间数据交换的机制,在分别研究了IGES标准和STEP标准的基础上,基于这2种标准进行了数据交换实验比较,提出了基于STEP标准实现Pro/E和UG之间实体模型数据交换的方法.     

基于STEP标准的统一BOM模型研究

在产品生命周期中,BOM贯穿了设计、工艺、制造、计划、采购、销售、财务等几乎所有职能部门,各部门按照本部门的需要定制了各种BOM。在BOM的定制过程中往往没有统一的设计和管理规范,无法保证各BOM之间数据的一致性,这种现象严重影响了企业产品设计、生产和管理等过程的集成和效率,增加了产品生产成本、延长了产品开发周期,所以研究基于STEP标准的统一BOM模型对制造业信息化的进程具有十分重要的意义。文中首先剖析了企业中存在的多视图BOM,阐述了BOM多视图的演变过程,在此基础上提出了统一BOM模型,并基于STEP标准构建了统一BOM模型。实践证明,文中提出的基于STEP标准的统一BOM模型可以较好地解决多视图BOM的模型不统一问题。     

A database system of mechanical components based on geometric and topological similarity. Part I: representation

A database of mechanical components is an important issue for some manufacturing activities such as cost estimation, process planning, and design by case-based reasoning. In this paper, we give the representation scheme of the CAD model in such a database. Components are represented using attributed graphs in which the nodes correspond to the surfaces of the component and the links correspond to the edges of the component. The graph is based on the standard for the exchange of product information (STEP) physical file of the component. STEP file should be unique for a single component regardless of the underlying CAD system. The process of creating the graph of a component constitutes two sub-tasks: (i) importing the CAD model from the CAD system in STEP format and (ii) transforming the STEP data into attributed graph-based representation. The graph and its attributes describe the topology of the component completely together with some geometric data that are not dependent on any coordinate system such as surface type and curve type. These geometric data are helpful in the retrieval and matching processes in the database.     

并行工程中产品信息集成研究

如何解决产品设计的信息集成问题一直是并行工程研究的一个重要课题。文章从信息集成的需求出发,定义了产品数据和产品信息模型,分析了基于STEP国际标准和特征建模技术的信息集成的方式。然后提出了一种并行工程信息集成的方式,在传统的CAD软件的基础上,参考STEP国际标准增加了产品的特征建模,通过STEP中性文件实现了并行工程中的产品信息集成。该系统在航天某型号部件XXX的设计和制造中得到了应用。     

A step toward STEP-compatible engineering data management: the data models of product structure and engineering changes

In an iterative design process, there is a large amount of engineering data to be processed. Well-managed engineering data can ensure the competitiveness of companies in the competitive market. It has been recognized that a product data model is the basis for establishing engineering database. To fully support the complete product data representation in its life cycle, an international product data representation and exchange standard, STEP, is applied to model the representation of a product. In this paper, the architecture of an engineering data management (EDM) system is described, which consists of an integrated product database. There are six STEP-compatible data models constructed to demonstrate the integratibility of EDM system using common data modeling format. These data models are product definition, product structure, shape representation, engineering change, approval, and production scheduling. These data models are defined according to the integrated resources of STEP/ISO 10303 (Parts 41-44), which support a complete product information representation and a standard data format. Thus, application systems, such as CAD/CAM and MRP systems, can interact with the EDM system by accessing the database based on the STEP data exchange standard.     

Active database support for STEP/EXPRESS models

The ISO STEP specifications aim to provide an effective means through which product information can be shared and exchanged between applications and enterprises. EXPRESS is a modelling language within the STEP specifications, which is used to describe product data. An EXPRESS model can be implemented on a database repository, queried upon and manipulated. However, EXPRESS models capture only the static aspects of a system. In this paper, proposed extensions to the EXPRESS language are made in order to model the dynamic behaviour of products and processes. A translator is implemented to transform such models to an active database, which has been developed on an object-oriented database, ObjectStore. The active component of the system is based on CLIPS, an expert system. Throughout the paper, a case based on a workflow process is used to demonstrate how a model can be mapped onto an active database.     

XML-based data processing in network supported collaborative design

In the course of network supported collaborative design, the data processing plays a very vital role. Much effort has been spent in this area, and many kinds of approaches have been proposed. Based on the correlative materials, this paper presents extensible markup language(XML)based strategy for several important problems of data processing in network supported collaborative design, such as the representation of standard for the exchange of product model data(STEP)with XML in the product information expression and the management of XML documents using relational database. The paper gives a detailed exposition on how to clarify the mapping between XML structure and the relationship database structure and how XML-QL queries can be translated into structured query language(SQL) queries. Finally, the structure of data processing system based on XML is presented.     

EXPRESS与SQL语言自动转换的实现

数据库交换方式是STEP实现产品数据交换的主要方式。通过将EXPRESS语言翻译成SQL语言,可以实现产品数据模型到关系数据库系统的转换。该文采用面向对象语言的编译方法实现了两种语言间的自动转换,从而克服了手工转换的繁琐、易出错的缺点,提高了应用效率。