基于组件的开放式CAD系统模型

在回顾CAD系统的几类系统模型并分析其优缺点的基础上，立足于CAD系统的开放性、集成性和效率，运用基于组件的软件工程技术，提出了CAD系统组件模型，并详细地分析了模型中各组件的功能和组件间的通讯.系统模型具有两级总线结构，较之以往的模型，其开放性大大提高，便于实现结构灵活、开放性强的实用系统.同时，组件也为软件复用建立了良好的基础.     

基于组件的分布式产品数据管理系统设计与实现

提出了基于组件技术实现分布式产品数据管理系统的方法，在简要介绍了当前组件技术标准的基础上，研究了基于组件技术的软件开发的原则和方法，最后给出了一个开发实例。     

面向企业级构件建模的移动Agent迁移组件技术研究及应用

在移动Agent迁移中引入EJB企业级组件对象的动态迁移,在基于移动Agent迁移基本原理、EJB组件标准的基础上,提出了一个通用的基于移动Agent的EJB对象迁移组件模型,采用面向企业级构件建模方法,给出了整个迁移组件模型的划分和功能说明,最后举了一个迁移组件模型的应用系统实例.     

基于组件动态多维模型的组件库架构

基于组件的软件开发是一种用来提高复用水平的最有前途的软件工程技术．而基于组件开发的最重要的问题之一就是如何能最有效的建立、维护和使用组件库．本文从不同的视角来反映组件的整体特征，每个视角称为一个“维”．又从静态和动态两个方面来阐述组件库的各个维，如描述维、部署维、案例维、测试维、需求维、创建和维护维、应用维、度量维等，提出了组件库的元模型．在此基础上又给出了基于组件动态多维模型的组件库的实现架构．     

分布式对象技术——CORBA和EJB组件模型的研究

本文主要介绍了CORBA和EJB两种组件模型的特点，以及两种基于组件模型标准的Web应用体系结构的比较，最后提出了新一代的组件模型SOAP。     

J2EE框架下组件检索方法研究

分析了传统的基于刻面的组件检索方法在组件功能和组件具体规范方面处理的不足,然在传统方法的基础上提出了一种改进的组件检索方法,提供了相应的组件检索描述模型,其主要特征是将组件功能用具体接口来描述,同时将J2EE平台组件规范融入到组件检索描述模型中,用试验结果比较了这两种算法.     

虚拟原型多体动力学约束模型研究

并行工程角度出发的机械虚拟原型是集成了产品的设计、分析，不断迭代、优化的过程，模型的协调一致性是保证设计过程完整的关键，如产品模型在CAD模型与机械多体动力学模型中的一致性表达。在这种观点下，该文提出在建立基于组件的机械系统虚拟原型时，从CAD中抽取多体动力学模型构件的物理属性，研究了国产三维实体设计软件CAXA环境下，基于多刚体系统动力学笛卡尔方法，从CAD模型映射多刚体动力学分析模型语义的实现方案。分析了多刚体系统动力学模型语义下，多体动力学约束模型坐标基变换关系的抽取。实验结果表明，从CAD中抽取多体动力学模型的物理属性的方案是可行的。可以用于建立基于组件的多体系统虚拟原型的分析模型，实现自主开发设计、分析集成的机械虚拟原型。     

基于组件结构的软件二次开发接口的设计与实现

提供二次开发手段是许多像CAD系统等应用软件的必要功能，文章提出了利用组件技术实现应用软件二次开发的接口模型。该模型结构层次清晰，各模块接口规范，易于扩充，并结合实际开发的应用系统，详细地分析了该模型中各组成部件的结构、功能和实现方法。     

基于COM的CAD软件二次开发平台的构建

组件对象模型(COM)是微软公司的重要技术之一。在介绍COM的基础上，讨论了CAD软件对二次开发支持的重要性和意义，阐述了利用COM技术进行构建CAD软件二次开发平台的一般过程，最后以已构建的捷惠CAD软件二次开发平台为例，简要地说明了利用此平台创建的用户程序的实际运行情况。     

利用组件技术开发三维标准件库

针对国内大多数三维标准件库存在的CAD／CAM平台依附性强的缺陷，以COM技术为基础，采用Windows DNA结构，将不同平台标准件库中的重复部分提取出来，以核心组件群的方式表示，并在这个组件群的基础上提出一个面向多个三维造型平台的标准件库系统的解决方案。     

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.     

一元化特征建模技术研究

特征建模是实现ＣＡＤ／ＣＡＭ以及并行工程中信息集成的键。一元化征建模技术融特征设计和特征识别两者一体，设计阶段的初始设计特征进入应用领域后，经过特征识别器表成领域专用特征。     

基于STEP的CAD/CAPP/CAM集成系统的研究

CAD／CAM／CAPP系统集成的关键是CAD、CAM、CA：PP系统间数据的交换和共享。STEP作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。文章介绍了基于STEP的两种主要的集成方式：基于中性文件的集成方式和基于共享数据库的集成方式,最后分析了系统集成技术的发展趋势。     

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3D CAD模型的设计结构矩阵自动化生成系统

设计结构矩阵DSM已成为许多研究和实践领域中复杂系统建模和分析的工具。但是,DSM的构建却面临很大的困难,因为每个产品的分解和结构关系可以有不同的解释,因此不能以标准模式构建。这使得DSM的快速生成难以实现,从而延长了产品设计周期。介绍了一种基于CAD模型的DSM自动生成系统。首先,使用SolidWorks API提取SolidWorks平台中CAD模型的结构特征树中的顶层部件的Mates特征信息,并将其按特定顺序排列并存储在数据库中。其次,分析组装的部件之间的几何关系,以确定各种配合的类型对部件之间的连接关系的影响程度,并建立了相应的分析和比较规则。最后,使用Visual Basic成功完成了DSM自动生成系统的设计。同时,本文以一些CAD模型为例,验证了所开发系统的可行性和可靠性。     

基于智能线模型管道CAD系统中的管线特征智能定位研究与开发

作为一种构件而被引入管道CAD系统的智能线,在这里扩展成为描述管线的模型.为提高管道CAD系统的特征定位效率,提出了平剖图的3种模式并介绍了若干基于智能线模型的启发式算法,已使得管线特征自动定位在局部范围内成为可能.     

Extended 3D annotations as a new mechanism to explicitly communicate geometric design intent and increase CAD model reusability

A successful implementation of the Model-Based Enterprise concept (MBE) requires maximizing the potential benefits of annotated 3D models. The foundations of the MBE model are established by digital product definition data practices, which are currently regulated by standards such as ASME Y14.41-2003 and ISO 16792:2006. At the center of the MBE concept is the notion of CAD model reusability, which relies on the idea that 3D CAD models can be reused both throughout the entire product lifecycle and as a starting point for future development of new products. In this context, a critical aspect of CAD model reuse is the proper identification and understanding of the geometric design intent that is usually expressed implicitly within the CAD model.In this work, we present a method to communicate geometric design intent explicitly by overloading and extending the scope of the current annotation instruments available in the MBE approach. We propose a new broader type of model annotation that we call “extended annotation”, where design information is represented both internally within the 3D model and externally, on a separate repository. This structure naturally demands additional mechanisms to support the interaction of users with the information. In order to manage the information stored in these extended annotations effectively, we implemented an annotation manager that automatically synchronizes the dual representation of the annotations. To reduce the visual clutter in the 3D model, the software provides powerful filtering, editing, and visualization capabilities, giving users complete control of the information stored in the model. Finally, a study was conducted with 60 participants to evaluate the performance of the proposed model and the usability of the annotation manager. Results show a statistically significant benefit of using the extended annotation system, suggesting the use of this model as a valuable approach to improve design intent communication.     

A STEP-compliant process planning system for CNC turning operations

Over the last 50 years, there have been many significant enhancements in computer aided systems which have influenced the CNC technology. One area that can be considered as a bottleneck to these CNC enhancements, and in particular to interoperability in CNC manufacturing is G&M part programming (ISO 6983). To overcome this bottleneck, the new standard ISO 14649, known as STEP-NC, is being developed to provide detailed information on component design, process planning and machining strategies to manufacture parts for the next generation of intelligent CNCs. This standard forms the basis of a new paradigm shift in the CNC domain to support digital modelling of CNC manufacturing resources. The research in this paper aims to identify major issues and develop new software tools to demonstrate the feasibility of interoperable CNC manufacturing based on STEP-NC. Besides the literature review on recent research and development on STEP-NC, this paper proposes a Process Planning System (PPS) with surface roughness chosen as the process planning objective. PPS consists of five modules: program reader, process planner, STEP-NC CAD viewer, STEP-NC CAM viewer and program writer. The reader is responsible for interpreting the geometry and the manufacturing data from a STEP-NC text file into a stored data list. The process planner uses this data list and enables users to evaluate surface roughness based on a mathematical model. Through the STEP-NC CAD viewer, the part geometry can be shown and via the STEP-NC CAM viewer the toolpath can be verified. Finally, the writer converts the stored STEP-NC data of the system into an updated STEP-NC file. An example case study component is used to demonstrate the PPS and show the interfacing of the STEP-NC data.     

基于软件总线的遗留CAD系统再开发

探讨从遗留的CAD系统中获得有效信息、组件的方法和过程,结合当前CAD领域的新发展,提出一种新的基于软件总线体系结构的CAD系统模型,并分析了组成该模型的各组件的功能特性。该系统具有较好的开放性与集成性,使处于异地的设计人员能协同工作。文中也给出了该体系结构在博士CAD系统中的应用实例。     

基于Inventor的三维参数化部件库系统的开发方法

介绍了基于AutodeskInventor的部件库的体系结构和实现方法。把部件库系统分为零件库和部件库两层结构,通过部件模型确定组成部件的组成零件及其装配关系,通过数据表和程序确定零件的规格。此方法解决了常用三维CAD软件不直接支持装配件参数驱动的问题,使得基于三维CAD软件创建部件库系统成为可能。文中所述部件库系统是使用VC++对Inventor进行二次开发而得到的。同时,该方法也适用于其他常用三维CAD软件。