面向并行工程的集成产品信息建模技术研究

针对并行工程的需求提出广义特征概念，基于广义特征和参考ＳＴＥＰ标准，建立了面向并行 集成产品信息模型，借助所建立的集成产品信息模型实现ＣＡＤ／ＣＡＰＰ／ＣＡＭ的信息集成，从而为实现产品并行开发过程的信息集成和功有集成打下了良好的基础。     

在汽车铸锻模中的应用

近年来，汽车市场竞争日趋激烈，人们对汽车的性能、内在质量、外观造型不断地提出更高的要求，从而加速了汽车的更新换代。为了适应当前技术革命迅速发展的形势，增强产品的开发能力，进一步提高企业的技术水平，完善我厂的模具CAD／CAM系统，我厂在成功应用EUCLID软件的基础上，引进了第三代CAD／CAM软件Pro／ENGINEER．14（Pro／E）。Pro／E作为我厂模具CAD／CAM的主要支撑软件之一，经过一段时间应用，已开始在模具开发中发挥效益。实践证明，该软件确实为性能卓越的模具CAD／CAM软件。1．Pro／E建模Pro／E是以参数…     

基于广义Choquet模糊积分的语言特征对象近似识别/分类

语言特征存在于许多实际应用中，如模糊数知识系统、语义检索、模糊人脸识别等．为解决这类具有语言特征(模糊数)对象的识别／分类问题，提出了基于广义Choquet模糊积分的分类方法与模型．该方法不仅可以解决数值特征对象识别／分类问题．同时为具有模糊数特征的对象识别／分类问题提供了手段，从而扩大了原有分类模型的适用领域．模糊人脸识别模拟实验证明，在语言特征环境下．该分类模型有效地实现了语言模糊对象的近似辨识．     

面向印刷机械行业分享成功经验Pro／ENGINEER软件面向印刷机械行业应用研讨会成功召开

2005年4月26日下午，在风景秀丽的北京昌平静之湖度假酒店，PTC公司亚太区最佳合作伙伴——北京艾克斯特公司与来自印刷机械行业的Pro／E用户相聚一堂，召开“Pro／E软件面向印刷机械行业应用研讨会”。     

面向异构CAD平台的工程辅助绘图系统的研制

工程图是进行工业生产和技术交流的重要文档,而在三维CAD系统中制作标准化的工程图比较烦琐．通过分析UG和Pro／E等系统工程图模块功能的不足,充分考虑不同平台二次开发的差异,借鉴成熟的软件体系和先进的开发工具,提出了一个通用的面向异构CAD平台的工程辅助绘图软件框架;并详细讨论了物理模块部署、逻辑对象构造和实例维护、工程随动约束管理以及产品装配模型访问等关键技术;研究开发了实用系统并在企业中得到应用．     

基于Pro/E的离心蜗壳三维模型设计

分析了目前离心泵蜗壳在三维模型设计中存在的问题，采用Pro／E零件模块和曲面造型模块的三维造型功能和实体转换特征，提出了一种离心泵蜗壳实体模型构造和研究的新方法，为离心蜗壳的三维模型设计与生成准确的工程图之间提供了一种新思路。生成的Pro／E参数化图形直观、简洁、形象，便于修改设计和对产品进行系列化设计。为采用有限元分析方法和流体动力学分析方法进一步研究离心泵蜗壳提供了实体模型。     

Pro/E环境下快速生成符合国标工程图的方法

提出了对Pro／E系统参数和模板进行修改的方法和步骤，在Pro／E环境下快速、方便地生成符合中国国标的二维工程图。所述方法免去了在三维CAD软件和二维CAD软件之间转换工程图的麻烦，又能充分利用Pro／E全尺寸相关的特点，提高了设计效率，是一个可行的二维工程图国标化解决方案。     

基于特征设计的CAD系统

介绍基于Ｐｒｏ／ＥｎｇｉｎｅｅｒＣＡＤ系统，借助于Ｐｒｏ／Ｄｅｖｅｌｏｐ开展工具二次开发的基于特征设计的ＣＡＤ系统，该系统操作简单方便设计效率高，可方便地对特征增加附加信息，为后续过程提供了丰富的信息，便于ＣＡＤ与后续过程的信息集成和功能集成，提出广义特征概念，为基于广义特征建立产品集约信息模型打下了良好的基础。     

产品集成建模及其关键技术

本文首先阐明了产品集成建模的概念和内容，提出了一种面向CIM的、基于特征的、以产品为核心的对象建模策略；给出一个特征分类、特征表示及特征对象模型；讨论了规范化、具体化的概念及实现方法。     

并行CAD/CAM集成策略与系统构架

本文提出并行协同设计环境下CAD／CAM的集成策略；产品模型基于特征表示，设计模型与制造模型有机并存且相互关联，制造模型从产品中识别出来；设计了并行CAD／CAM集成系统构架。并对该构架中各个组成部分的功能进行了介绍。     

基于特征模型的软件产品线可变性建模方法

特征建模是软件产品线开发中的一项关键活动,对特征可变性和特征依赖的建模是特征模型中最重要的组成部分。阐述了特征模型的元模型,着重讨论了特征可变性建模过程,详细分析了特征可变性、特征之间关系、特征依赖类型的识别方法和使用特征依赖矩阵的表示方法。在此基础上,还通过一个库房监视系统应用软件的产品线可变性建模实例验证了该方法的有效性。     

文本分类中CTM模型的优化和可视化应用研究

如何从海量文本中自动提取相关信息已成为巨大的技术挑战,文本分类作为解决该问题的重要方法已引起广大关注,而其中文本表示是影响分类效果的关键因素。为此采用相关主题模型进行文本表示,以保证信息完整同时表现主题相关性;基于该模型,对主题数目和特征提取实施了优化处理,综合复杂度和对数似然函数来确定最优主题数目,引入基于互信息的主成分分析算法进行最优特征提取,降低数据维度和特征冗余,使用R语言进行可视化实验分析。     

Feature-based ontological framework for semantic interoperability in product development

An essential requirement in integrating tasks in product development is to have a seamless exchange of product information through the entire product lifecycle. A key challenge in the integration is the exchange of shape semantics in terms of understandable labels and representations. A unified taxonomy is proposed to represent, classify, and extract shape features. This taxonomy is built using the Domain-Independent Form Feature (DIFF) model as the representation of features. All the shape features in a product model are classified under three main classes, namely, volumetric features, deformation features and free-form surface features. Shape feature ontology is developed using the unified taxonomy, which brings the shape features under a single reasoning framework. One-to-many reasoning framework is presented for mapping semantically equivalent information (label and representation) of the feature to be exchanged to target applications, and the reconstruction of the shape model automatically in that target application. An algorithm has been developed to extract the semantics of shape features and construct the model in the target application. The algorithm developed has been tested for shape models taken from literature and test cases are selected based on variations of topology and geometry. Results of exchanging product information are presented and discussed. Finally, the limitations of the proposed method for exchanging product information are explained.     

并行工程下产品协调模型的研究

建立和维护产品全生命周期中各种应用活动之间动态的信息关联,是实现产品数据集成、保证各应用领域协调活动的关键,为此,提出了基于产品设计过程的产品协调模型,该模型将原用于基于历史的几个何特征建模的特征编码作为建立和维护产品几何信息及其它应用信息间关联的纽带,为了屏蔽特征编码机制的私有属性,建立了比特征编码机制更高层的协议－数据协调协议,该协议为在产品几何信息与非几何应用信息之间建立和维护动态的、协调一     

文本分类中一种混合型特征降维方法

提出一种基于特征选择和特征抽取的混合型文本特征降维方法,分析基于选择和抽取的特征降维方法各自的特点,借助特征项的类别分布差异信息对特征集进行初步选择。使用一种新的基于PCA的特征抽取方法对剩余特征集进行二次抽取,在最大限度减少信息损失的前提下实现了文本特征的有效降维。对文本的分类实验结果表明,该特征降维方法具有良好的分类效果。     

Viewer-centered geometric feature recognition

Computer aided design (CAD) and computer aided manufacturing (CAM) systems are now indispensable tools for all stages of product development. The flexibility and ease of use of these systems has dramatically increased productivity and quality of product while reducing lead times. These advances have been largely achieved by automating individual tasks. At present, these islands of automation are poorly linked. One reason for this is that current computer systems are unable to extract geometric and topological information automatically from solid models that is relevant to the down-stream application. In other words, feature information.The objective of the research reported in this paper was to develop a more generic methodology than heretofore, in order to find the generic protrusion and depression features of a CAD model. The approach taken is one relying on a more human type of analysis, one that is viewer-centered as opposed to the object-centered approach of most previous research in this area. The viewer-centered approach to feature recognition described is based on a novel geometric probing or tomographic methodology. A five-step algorithm is described and then applied to a number of components by way of illustration.     

语义特征造型中特征修改优先准则的研究

特征造型技术是新一代CAD系统的关键技术,是产品模型技术的核心。该文讨论了以细胞元模型为基础的语义特征造型技术。在语义特征造型中用特征依赖图（FDG）的数据模型来保存和维护设计中的各种特征信息及其之间的关系,在此基础上分析了依据特征依赖图中特征间的关系动态修改特征优先级的方法,确保了模型修改的有效性。最后给出了一个实例。     

Supporting feature model refinement with updatable view

In the research of software reuse, feature models have been widely adopted to capture, organize and reuse the requirements of a set of similar applications in a software domain. However, the construction, especially the refinement, of feature models is a labor-intensive process, and there lacks an effective way to aid domain engineers in refining feature models. In this paper, we propose a new approach to support interactive refinement of feature models based on the view updating technique. The basic idea of our approach is to first extract features and relationships of interest from a possibly large and complicated feature model, then organize them into a comprehensible view, and finally refine the feature model through modifications on the view. The main characteristics of this approach are twofold: a set of powerful rules (as the slicing criterion) to slice the feature model into a view automatically, and a novel use of a bidirectional transformation language to make the view updatable. We have successfully developed a tool, and a nontrivial case study shows the feasibility of this approach.     

Integrated manufacturing features and Design-for-manufacture guidelines for reducing product cost under CAD/CAM environment

The main contribution of the work is to develop an intelligent system for manufacturing features in the area of CAD/CAM. It brings the design and manufacturing phase together in design stage and provides an intelligent interface between design and manufacturing data by developing a library of features. The library is called manufacturing feature library which is linked with commercial CAD/CAM software package named Creo Elements/Pro by toolkit. Inside the library, manufacturing features are organised hierarchically. A systematic database system also have been developed and analysed for each feature consists of parameterised geometry, manufacturing information (including machine tool, cutting tools, cutting conditions, cutting fluids and recommended tolerances and surface finishing values, etc.), design limitations, functionality guidelines, and Design-for-manufacture guidelines. The approach has been applied in two case studies in which a rotational part (shaft) and a non-rotational part are designed through manufacturing features. Therefore, from manufacturing feature library a design can compose entirely in a bottom-up manner using manufacturable entities in the same way as they would be produced during the manufacturing phase. Upon insertion of a feature, the system ensures that no functionality or manufacturing guidelines are violated. The designers are warned if they attempt to include features that violate Design-for-manufacture and Design functionality guidelines. If a feature is modified, the system validates the feature by making sure that it remains consistent with its original functionality and Design-for-manufacture guidelines are re-applied. The system will be helped the process planner/manufacturing engineer by automatically creating work-piece data structure.