STEP/AP203一致性测试软件的实现

STEP一致性测试保证实施过程中产品数据的一致性和完整性。文章通过对STEP一致性测试方法的研究,结合STEP/AP203一致性测试软件的实现,讨论了测试系统的结构、测试过程和内容,重点分析了对交换结构的规则与约束的检查,最后介绍了软件系统开发过程中的相关技术问题。     

ICCC上STEP part 203前后处理器的设计与实现

STEP(the STandard for the Exchange of Product model data)标准是一个服务于CAD/CAM领域的覆盖产品整个生命周期的形式化的产品数据交换标准,其应用协议的研究开发与实现具有广泛的应用价值.本文主要介绍了STEP标准应用协议配置控制设计STEP part 203的前后处理器的设计与实现,包括应用协议的EXPRESS描述编译、几何拓扑映射、面片合成、中性文件交换、在SUN SPARCworkstation上的处理器实现和零件输入输出测试等内容.     

基于STEP/AP209的有限元后处理技术研究

STEP是关于产品生命周期中数据表达和交换的国际标准。SDAI是STEP采用的标准数据存取接口,是针对不同的数据存贮技术而提供的统一的数据存取接口标准。文章通过SDAI标准数据存取接口,来实现有限元分析本体程序和后处理系统之间的数据交换,在此基础上实现了STEP/AP209格式文件的读入,并对有限元后处理技术进行了研究。     

面向开放环境的集成化STEP工具集GS—STEP的设计与实现

GS－STEP是一个面向开放环境的STEP信息集成工具集,为适应开放式CIMS环境对信息集成的柔性需求,采用了系统独立性、协议无关性和层次化、模块化的开发策略。这些策略使GS－STEP能够方便地应用于各种CAx系统,也使其各功能部件可作为独立的软件包或开发平台分别实现商品化,从而体现“即插即用”思想与可扩充性原则。该软件作为信息集成平台已成功地应用于CIMS集成环境GS－ICCC。文中从开发策略、系统结构、数据流和功能组织等角度阐述了GS－STEP的设计与实现。     

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GHModeIing4.O的STEP中性文件前后处理器的实现．文中详细地讨论了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效据交换中的作用．     

基于STEP的特征模型及重构算法

随着CAX技术的发展,特征技术得到越来越多的重视,特征技术的使用,大幅度提高了产品的设计、制造、集成等过程的效率。目前,基于特征的CAD、CAM系统是市场的主流,CAPP是完全基于特征的应用系统。但是在STEP的众多应用协议中,涉及机械设计、制造、管理的应用协议有很多,但是这些应用协议基本上没有提供对特征的支持。AP224是较早支持特征的STEP应用协议,主     

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数据核的有限元后处理技术的研究

文章在现有的有限元本体程序和产品数据交换国际标准STEP的基础上,提出一种通用的有限元数据交换模型。以集成资源STEP/AR104为基础构建一个能满足有限元后处理需要的数据核,来实现有限元分析本体程序和后处理系统之间的数据交换,并用OpenGL对其数据进行可视化。利用STEP中性文件机制,可以实现后处理系统与多个有限元分析本体程序之间的连接。     

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。     

AUTOSAR标准一致性测试研究

分析AUTOSAR一致性测试过程,采用eclipse、TTthree、μTTman等工具,基于TTCN-3测试系统架构,实现AUTOSAR一致性测试。针对简单信号灯系统,研究测试系统中测试套、编解码器和适配器的功能及相关实现方法,并验证采用TTCN-3进行AUTOSAR一致性测试的可行性。     

基于CORBA标准的STEP数据库的实现研究

为解决企业间跨异构平台的产品数据共享问题,采用面向对象的设计方法将ＣＯＲＢＡ标准与ＳＴＥＢＰ标准有机地结合起来,实现了基于ＳＴＥＡＰ２０３全局数据模型的集成虚拟企业产品数据存储系统－ＳＴＥ数据库。     

Architecture and implementation of a shop-floor programming system for STEP-compliant CNC

STEP-NC (formalized as ISO 14649 and ISO 10303 AP238) is a new interface (or language) standard for the CAD-CAM-CNC chain, currently under establishment by ISO TC184 SC1 and SC4. Upon completion, it will replace ISO 6983, so called M & G codes used for CNC since 1950s. As the new language is being established, a new CNC controller called STEP-CNC (STEP-compliant CNC), capable of carrying out various intelligent tasks using the new language as an input, receives worldwide attention. Shop-floor programming (SFP) system is a computer-assisted part programming system interfaced with STEP-CNC. Its primary function is to generate part program in ISO 14649 (or STEP AP238) to machine the part geometry given by STEP AP203 or AP224 file. In this paper, we first present an architecture for the SFP system, followed by implementation technology including: (1) STEP physical file interpretation, (2) feature recognition, (3) process planning, (4) part program generation, and (5) verification. The developed methodology was implemented in a prototype called PosSFP, and tested with Korea STEP-NC system.     

A survey on 3D CAD model quality assurance and testing tools

A new taxonomy of issues related to CAD model quality is presented, which distinguishes between explicit and procedural models. For each type of model, morphologic, syntactic, and semantic errors are characterized. The taxonomy was validated successfully when used to classify quality testing tools, which are aimed at detecting and repairing data errors that may affect the simplification, interoperability, and reusability of CAD models.The study shows that low semantic level errors that hamper simplification are reasonably covered in explicit representations, although many CAD quality testers are still unaffordable for Small and Medium Enterprises, both in terms of cost and training time. Interoperability has been reasonably solved by standards like STEP AP 203 and AP214, but model reusability is not feasible in explicit representations.Procedural representations are promising, as interactive modeling editors automatically prevent most morphologic errors derived from unsuitable modeling strategies. Interoperability problems between procedural representations are expected to decrease dramatically with STEP AP242. Higher semantic aspects of quality such as assurance of design intent, however, are hardly supported by current CAD quality testers.     

Conformance checking of PMI representation in CAD model STEP data exchange files

Recommended practices supplement data exchange standards by providing common implementation guidance associated with specific requirements. ISO 10303 (STEP) product data exchange files that conform to recommended practices ensure interoperability between computer-aided design (CAD) systems and with downstream applications such as manufacturing and inspection. Correct implementation of product and manufacturing information (PMI)–annotations associated with a CAD model’s edges and faces such as geometric tolerances, dimensional tolerances, and datum features–in CAD authoring systems and translators is essential for interoperability. This paper discusses an approach implemented in a software tool for checking the conformance of STEP files to the recommended practice for PMI representation.     

基于工艺特征识别技术的数控自动编程方法研究

研究从基于STEPAP203标准的中性文件中提取零件工艺特征以及根据工艺特征建立加工工艺的方法。分析了STEPAP203文件及其数据结构,运用VB.NET语言进行词法分析,根据电极工艺特征的特点,研究出了从STEP文件中提取并识别简单工艺特征的方法。根据零件的不同加工方法,利用PowerMILL的"宏指令"功能保存电极的优秀编程资源,建立了可重用的加工工艺数据库,最后建立加工工艺与工艺特征之间的映射关系。所采用的工艺特征识别方法能够识别常用的模具电极工艺特征,与可重用的加工工艺结合能够实现特征识别系统与CAM系统的无缝连接。     

Mapping 2D midship drawings into a 3D ship hull model based on STEP AP218

Standard for the exchange of product model data (STEP) AP218 has a standard schema to represent the structural model of a midship section. While its schema facilitate the exchange of ship structural models among heterogeneous systems, most shipyards and classification societies exchange information using 2D paper drawings. We propose a feature parameter input method to generate a 3D STEP model of a ship structure from 2D drawings. We have analyzed the ship structure information contained in 2D drawings and have defined a data model to express the contents of the drawing. We also developed a GUI for the feature parameter input. To translate 2D information extracted from the drawing into a STEP AP218 model, we have developed a shape generation library and have generated the 3D ship model through this library. The generated 3D STEP model of a ship structure can be used to exchange information between design departments in a shipyard as well as between classification societies and shipyards.     

Standardized data exchange of CAD models with design intent

Modern CAD systems generate feature-based product shape models with parameterization and constraints. Until recently, standards for CAD data exchange among different CAD systems were restricted to the exchange of pure shape information. These standards ignored the construction history, parameters, constraints, features and other elements of ‘design intent’ present in the model to be transferred. This paper suggests an implementational foundation for CAD data exchange with the preservation of design intent, based on the use of newly published parts of the International Standard ISO 10303 (STEP). Case studies are presented which employ a hypothetical STEP application protocol (AP) using Parts 55, 108 and 111 of ISO 10303. A prototype translator based on this AP has been implemented and tested. The paper reports on the experience gained in ‘intelligent’ data exchange.