数控代码解释器模块化结构的研究与实现

为了提升数控系统的效率和功能,提出模块化的解释器结构模型.该模型将整个解释器分为词法分析模块,语法分析模块和解释执行模块3个模块.在词法分析模块中,提出利用EBNF(Extended Backus-Naur Form)对标准数控代码规则进行形式化描述的方法,并采用自顶向下的递归下降分析构建词法分析程序.通过将词法分析得到的数据存入设计好的加工信息存储结构,实现了数控指令的形式化表达.加工命令转化模块将加工数据转化成相应的数控指令送入系统底层模块.详细阐述了各模块的构建方法,并开发了一个简单的解释器原型系统,验证了所提方法的有效性,为高性能数控代码解释器的实现提供了技术支持.     

产品模型数据交换标准STEP研究

在设计和制造中,许多系统过去常常要处理技术产品数据.每个系统有它自己的数据格式,所以相同的信息必然在多个系统中多次存储,这会导致了信息的冗余和错误.STEP是一个广泛使用的ISO标准(ISO 10303),描述了表示和交换数字产品信息的方式.研究了STEP的标准体系结构,并研究不同应用对象的STEP和STEP未来的发展趋势.     

基于J2EE开源框架的业务组件代码生成器设计

根据J2EE体系结构特点,提出基于模板技术的代码自动生成模型,实现由业务模型描述文件到业务组件的自动生成。从分析J2EE结构入手,确定生成的目标代码,讨论基于模板技术的代码生成器原理和模型,设计模板文件,定义业务模型描述文件的规格,实现了代码生成器。介绍了应用代码生成器的开发模式。     

网络化制造中基于STEP-NC的编程方法

STEP-NC是由欧美提出的新的数控接口标准，目的是取代旧的数控标准ISO6983。本文首先分析了STEP-NC的两种应用标准：ISO14649（ARM）和STEPAP238（AIM），并且分析了Part21和Part28的应用领域及Part21文件格式和其中的信息产生方法。然後介绍了ST-Developer环境下ROSEC＋＋颠库编程接口及其应用程序的早、晚编联方式，并且以此为基础设计了整个程序的编程流程，重点介绍了工艺规划设计。最后给出了在C＋＋编程环境下利用ROSE库函数写入形成STEP AP238文件的方法。     

基于STEP标准的产品功能信息建模

分析了集成信息CAD系统中要解决的产品模型信息描述问题。基于STEP标准和IDEF产品建模方法,提出了基于功能层的产品信息建模和产品信息模型的三层结构：功能层、零部件层和构造层。以工程中业已标准化的滚动轴承为对象建立了基于STEP标准的产品功能信息EXPRESS描述模型,为集成信息CAD系统的信息集成中性环境的建立提供了基础。     

基于编程语言结构的通用配置代码生成方法

设计一种可以生成不同编程语言配置代码的通用生成装置。提出一种基于编程语言结构的用户描述规范,用户使用简单的语法编写一个按照该规范描述目标代码数据结构的模块即可生成相应的可配置代码,并能生成多种编程语言的可配置代码文件。该装置可以方便地移植到各种开发语言环境的软件或硬件系统中,减少软件或硬件代码配置工作的开发工作量和开发时间。     

基于混合自动机的J2ME代码自动生成技术

在概述混合自动机理论的基础上,给出了它的一种基于xml语言的形式描述,并利用这种描述规范提出了一种基于混合自动机的模型驱动的开发方式,结合一个具体的应用实例进行开发,给出了根据模型描述文件生成可以编译运行的J2ME代码的原理以及关键步骤,以及需要注意的问题。     

基于XML的STEP-NC程序解释器的设计与实现

通过分析STEP-NC数据模型及程序结构,指出ISO10303 Part21物理文件格式数控程序不适合在网络上传输的缺点.因而在对现有数控系统进行基于STEP-NC的改造时,采用XML作为STEP-NC数控程序的文件格式,并提出面向网络化制造STEP-NC数控系统的基本框架,阐述了各组成模块的功能.同时从教据存储结构、解析XML、信息提取方法三个方面重点介绍基于XML的STEP-NC程序解释器的设计.最后采用JAVA语言实现了该解释器的功能,并通过STEP.NC标准草案里的一个实例验证该设计的正确性.     

集成于CAD系统的数控线切割自动编程系统

本文以具体例子说明了从CAD系统的零件描述中自动生成数控线切割程序系统的设计方法。读系统从提取CAD数据转换文件中的信息开始,自动识别零件的内外轮廓,确定切割方向和走刀路线,最终生成通用的数控程序,并利用后处理程序转换成特定数控加工程序。     

ARM数控系统高速处理串口数据的研究

数控实际加工先采用CAD/CAM软件画图,根据图形生成G代码,然后将G代码传送给数控系统来进行实际加工,实际一个工件生成的G代码相对ARM所拥有的存储资源而言很大,为了解决G代码传输速度与ARM数控系统代码处理速度不匹配问题.利用ARM的串口传送G代码,实现了ARM数控系统代码高速处理的同时,串口数据正确高速传送.经研究与实验,这种方法简单易行,在保证数据准确的前提下,提高了数据传输速度,提高了数控系统的加工效率.     

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.     

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.     

STEP一到性测试系统的开发

STEP AP 203（ISO10303－203－1994）是表达3D机械产品设计阶段的产品数据的国际标准,它提供了一种独立于任何特定系统的信息通信的中性机制,然而,如果不对应用系统进行确定其是否与标准相一致的测试,则产品数据交换的目标就不能完全达到,文中在给出STEP一致性测试的系统方法的基础上,通过已开发的STEP AP 203一致性测试系统,来说明如何实现STEP一致性测试。     

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。     

Dimensional metrology interoperability and standardization in manufacturing systems

Dimensional metrology is an important part of any manufacturing system. It consists of distinct components and requires a large, diverse, and interconnected knowledge base. How to pass information seamlessly with minimal cost and minimal data loss between different components of a dimensional metrology system is a major issue that concerns software and hardware vendors, standards developers, and customers. This paper focuses on the four main elements of a dimensional metrology system: product definition, measurement process plan definition, measurement process execution, and analysis and reporting of quality data. The activities and software modules that are involved in these elements are discussed. Key issues that cause interoperability problems are identified. These issues are discussed as they relate to the current situation in dimensional metrology standards development. The STEP (ISO 10303) standards are the product of an international effort to achieve interoperability for manufacturing systems. Extending STEP is an appropriate way to solve the interoperability problem within dimensional metrology systems. Further development of STEP standards is proposed so that Geometric Dimensioning and Tolerancing (GD&T) information already available in STEP can be linked with manufacturing feature information, measurement technology, and measurement results. The proposed STEP data model is an attempt to provide a standard that will support automatic measurement process plan generation for in-process on-machine measurement. Some case studies are under way to test the model.     

Design of a STEP compliant system for turning operations

The changing economic climate has made global manufacturing a growing necessity over the last decade, forcing companies from East and West to collaborate beyond geographic boundaries in the design, manufacture and assembly of products. The ISO 10303 and ISO 14649 Standards (STEP and STEP-NC) have been developed to introduce interoperability into manufacturing enterprises so as to meet the challenges of responding to production on demand. This paper describes and illustrates a STEP compliant CAD/CAPP/CAM System for the manufacture of rotational parts on CNC turning centers. The information models to support the proposed system together with the data models defined in the ISO 14649 standard used to create the NC programs are also described. A structured view of a STEP compliant CAD/CAPP/CAM system framework supporting the next generation of intelligent CNC controllers for turn/mill component manufacture is provided. Finally a proposed computational environment for a STEP-NC compliant system for turning operations (SCSTO) is described. SCSTO is the experimental aspect of the research and is supported by information models that and have been constructed using a structured methodology and object-oriented methods. SCSTO was developed to generate a Part 21 file based on machining features to support the interactive generation of process plans utilizing feature extraction. A case study component has been developed to prove the concept of using the milling and turning parts of ISO 14649 to provide a turn-mill CAD/CAPP/CAM environment.     

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.     

基于STEP的产品质量信息建模与共享技术

计算机集成制造(CIM)技术研究的难点之一是信息的集成。从技术发展看,CIM信息的集成两个层次,其一是(:IM系统中各“孤岛”之间信息的自动转换,其二是基于并行工程思想的信息共。由于历史原因,CAD、CAPP、IQS、CAM系统各自独立发     

Striving for a total integration of CAD, CAPP, CAM and CNC

Over the last 50 years, conventional programming of the numerical controlled (NC) machine tools has been based on a data model stipulated by ISO 6983, or otherwise known as G-codes. It was designed to sequentially pass instructions to the controls of machine tools with little, if any, intelligence. It has been realized that this standard has led to serious impediments for the fulfilment of total CAD/CAM integration. The forthcoming ISO 14649 defines a new interface for exchange of information between CAD/CAM systems and NC machine tools. ISO 14649 is strictly harmonized with ISO 10303 (STEP), hence the name STEP-NC meaning an extended STEP for numerical control. There has been substantial amount of research being carried out concerning STEP-NC, in particular EU and USA; its benefits and potentials are revealing and appealing. The manufacturing industry may have to embrace itself with a revolutionary change even more dramatic than that of introduction of numerical control about half a century ago.     

基于STEP装配特征的BOM信息提取和多视图映射

为了解决企业信息集成过程中CAD文件物料清单提取问题,提出一种基于STEP装配特征辨识的物料清单信息提取方法,该方法以STEP作为中间数据格式,采用统一建模语言建立实体类映射模型,利用模型的装配特征辨识实体的装配关系,实现异构数据物料清单统一提取。同时,在XMLwebServices框架的网络服务平台上,利用扩展样式表语言转换自动映射机制,有效实现物料清单多视图转换过程集成规范化。在此基础上建立了基于STEP产品物料清单信息管理系统,并给出了该系统在工程机械制造企业产品数据管理中的应用实例。