零件语义关系几何模型及其基因编码

为完整描述零件信息,通过分析零件的静态特征构成,定义拉伸和旋转等6种特征操作算子;研究特征间的动态语义关系,得出“和约束特征”和“并约束特征”两种合理性约束特征;将两者有机结合,实现静态特征间的动态语义连接,建立基于特征造型技术的零件语义关系几何模型（Part Semantic Relationship Geometry Model,PSRGM）．根据模型树的动态生成过程以及特征编码结构,完成特征基因编码,实现零件特征序列的DNA编码．以曲轴为例,说明该方法的应用．     

CAPP系统中零件信息模型自动获取技术研究

零件信息模型对 CAPP系统的可靠性和质量具有决定性作用 .针对当前的零件信息模型获取手段主要以手工或半自动为主 ,效率低下这一问题 ,对零件信息模型自动获取问题进行了研究 .给出了零件信息模型形式化表述 ,并提出自动获取零件信息模型框架及其关键技术 .最后 ,给出一个具体应用实例 .     

一种零件特征描述和信息模型建立方法

给出了一种零件特征描述和信息模型建立方法。首先对具体零件特征进行分析,在此基础上,针对性的给出零件特征描述方法,然后根据模型信息结构,给出模型的总体结构。该方法简单方便、实用性强。     

实数与二进制编码GA种群多样性统一数学模型

针对GA早熟收敛问题研究中存在的种群多样性定义缺乏统一性和普适性问题,基于GA基因层次种群多样性的本质,建立了实数和二进制编码的GA层次多样性的统一数学模型。首先,将实数编码GA的种群矩阵等效变换成与二进制编码GA种群矩阵相同的形式。其次,定义了类随机变量的概念及其特性指标:数学期望、偏离度以及方差;在此基础上建立了适于两种编码的种群多样性的统一模型,并给出了该模型的进化矩阵和图形化两种表示方法。对GA测试函数的仿真分析表明,该模型可以有效地体现和分析GA进化过程中种群多样性的变化趋势以及各基因位的收敛过程和收敛结果。最后,指出了进一步的分析思路和方向。     

CAPP系统中零售信息模型自动获取技术研究

零件信息模型对CAPP系统的可靠性和质量具有决定性的作用。针对当前的零件信息模型获取手段主要以手工或半自动为主，效率低下这一问题，对零件信息模型自动获取问题进行了研究，给出了零售信息模型形式化表述，并提出了自动获取零件信息模型框架及其关键技术，最后，给出一个具体应用实例。     

MC环境下基于加工特征的零件工时定额研究

工时定额是大规模定制生产模式下企业确定产品交货期和提高顾客满意度的重要参考依据。为更好地支持大规模定制生产的企业工时定额的制定,提出一种大规模定制环境下基于加工特征的零件工时定额的制定方法。在此方法中,运用面向对象方法将零件组内的加工特征进行分类、编码,建立加工特征信息模型,以便于零件加工特征的检索;采用神经网络技术,结合MATLAB软件针对编码系统中每一个最底层的加工特征建立对应的工时模型;根据零件加工特征的编码检索各个加工特征的工时模型,估算每个加工特征的加工工时,从而得到整个零件的工时定额。通过与传统的工时定额方法对比,验证了该方法的准确性和快速性。     

基于数据库ADO技术的动态零件族的研究与建立

为了有效地管理和利用标准化设计资源,真正意义上实现数据共享,对零件族的层次结构和事物特性表进行了分析,提出了一种基于数据库ADO技术的动态零件族的信息建模方法。它是一种零件族表达与信息模型无关、信息容量大且实用性强的零件族信息模型的建模方法,能有效地解决零件信息来源不同的问题。运用VC 的MFC AppWizard和数据库ADO等知识,给出了零件族的建立过程,实现了对零件族进行添加、修改和删除等动态信息维护。这为零件库信息模型更高层次的实现提供了基础。     

基于数据库ADO技术的动态零件族的研究与建立

为了有效地管理和利用标准化设计资源,真正意义上实现数据共享,对零件族的层次结构和事物特性表进行了分析,提出了一种基于数据库ADO技术的动态零件族的信息建模方法.它是一种零件族表达与信息模型无关、信息容量大且实用性强的零件族信息模型的建模方法,能有效地解决零件信息来源不同的问题.运用VC 的MFC AppWizaed和数据库ADO等知识,给出了零件族的建立过程,实现了对零件族进行添加、修改和删除等动态信息维护.这为零件库信息模型更高层次的实现提供了基础.     

多层次多方位的信息描述

零件信息描述对CAPP的成败起着决定性的作用。该文通过对零件信息描述的深入研究,提出了基于特征名形面名的多层次多方位的零件信息描述方法,及特征命名规则、面命名规则。这种方法通过对零件模型上的特征及其所依附的面的命名,详细清楚地描述了零件模型上各特征之间的层次结构、位置关系和方位。建立了面向对象的特征信息描述模型,清晰完整地表达了整个零件模型的信息。     

用AutoLisp实现特征造型

特征可以携带并传输大量的几何信息和非几何信息，在实现CAD／CAPP／CAM一体化技术中具有特殊意义。本文在讨论特征表达和特征建模的基础上，探讨了加工特征库的建立和特征实例化过程在AutoCAD环境中的具体实现方法，分析了程序设计的几个难点，最后给出零件的特征模型输出结果。     

Multiple-view feature modelling for integral product development

To allow a designer to focus on the information that is relevant for a particular product development phase, is an important aspect of integral product development. Unlike current modelling systems, multiple-view feature modelling can adequately support this, by providing an own view on a product for each phase. Each view contains a feature model of the product specific for the corresponding phase. An approach to multiple-view feature modelling is presented that supports conceptual design, assembly design, part detail design and part manufacturing planning. It does not only provide views with form features to model single parts, as previous approaches to multiple-view feature modelling did, but also a view with conceptual features, to model the product configuration with functional components and interfaces between these components, and a view with assembly features, to model the connections between components. The general concept of this multiple-view feature modelling approach, the functionality of the four views, and the way the views are kept consistent, are described.     

面向制造基于特征的零件定义模型的研究及其应用

零件信息的描述是建立适用ＣＥ／ＤＦＭ设计系统必须解决的问题,用于ＤＦＭ的 同于常规的ＣＡＤ／ＣＡＰＰ系统的零件模型。     

基于本体的零件描述模型研究

针对CAPP应用系统中零件信息的表达和组织问题，提出了基于本体的零件描述模型以及该模型的3层体系架构，并对该架构中的零件特征描述模型及其结构进行了介绍，最后通过案例验证零件信息的本体描述是合理且有效的方式。     

An approach to identify design and manufacturing features from a data exchanged part model

Due to the large variety of CAD systems in the market, data exchange between different CAD systems is indispensable. Currently, data exchange standards such as STEP and IGES, etc. provide a unique approach for interfacing among different CAD platforms. Once the feature-based CAD model created in one CAD system is input into another via data exchange standards, many of the original features and the feature-related information may not exist any longer. The identification of the design features and their further decomposition into machining features for the downstream activities from a data exchanged part model is a bottleneck in integrated product and process design and development. In this paper, the feature panorama is succinctly articulated from the viewpoint of product design and manufacturing. To facilitate feature identification and extraction, a multiple-level feature taxonomy and hierarchy is proposed based on the characteristics of part geometry and topology entities. The relationships between the features and their geometric entities are established. A litany of algorithms for the identification of design and machining features are proposed. Besides, how to recognize the intersecting features or compound features based on the featureless chunks of geometry entities is critical and the issue is addressed in the paper. A multi-level compound feature representation and recognition approach are presented. Finally, case studies are used to illustrate the validity of the approach and algorithms proposed for the identification of the features from CAD part models in neutral format.     

数据基因：数据的进化过程管理模型

同生物一样，数据也具有进化过程。本文参照生物进化论的观点，给出一种数据进化过程管理模型——数据基因模型。在数据基因模型中，数据进化过程中产生的信息称为数据的遗传信息，它们被保存在数据基因中。通过数据基因的遗传和变异来记录数据的特征及与其它数据的关系。该模型可用于企业信息处理、审计事务处理等对数据来源、去向需要清楚了解的应用中。本文给出了数据基因模型的基本概念、性质，并给出了模型的一个实例。     

3D clipping algorithm for feature mapping across domains

This paper describes an algorithm based on 3D clipping for mapping feature models across domains. The problem is motivated by the need to identify feature models corresponding to different domains. Feature mapping (also referred to as feature conversion) involves obtaining a feature model in one domain given a feature model in another. This is in contrast to feature extraction which works from the boundary representation of the part. Most techniques for feature mapping have focused on obtaining negative feature models only. We propose an algorithm that can convert a feature model with mixed features (both positive and negative) to a feature model containing either only positive or only negative features.The input to the algorithm is a feature model in one domain. The algorithm for mapping this model to another feature model is based on classification of faces of features in the model and 3D clipping. 3D clipping refers to the splitting of a solid by a surface. The feature mapping process involves three major steps. In the first step, faces forming the features in the input model are classified with respect to one another. The spatial arrangement of faces is used next to derive the dependency relationship amongst features in the input model and a Feature Relationship Graph (FRG) is constructed. In the second step, using the FRG, features are clustered and interactions between features (if any) are resolved. In the final step, the 3D clipping algorithm is used to determine the volumes corresponding to the features in the target domain. These volumes are then classified to identify the features for obtaining the feature model in the target domain. Multiple feature sets (where possible) can be obtained by varying the sequence of faces used for clipping. Results of implementation are presented.     

基于特征精化的产生式编程方法研究

针对当前产生式编程方法不能有效地应用于复杂软件系统（如信息系统）的开发，不能在分析和设计的层次上复用软件等问题，本文提出了一种基于特征精化的产生式编程方法，基本思想是首先使用特征模型（Feature Model）描述领域内的概念和特征，然后使用特征精化的方法将特征精化为基本特征，用基本特征和之间的关系说明特征是如何实现的，最后将基本特征映射为组件，根据系统的特征模型组装组件，构建整个软件系统。基于特征精化的产生式编程方法是建立在特征和组件的基础上的，适用于信息系统类软件的开发。     

Part design using manufacturing features

This paper presents a methodology by which manufacturability data is used to drive the design process. The system allows a designer to determine the features to be considered. He provides the basic geometric parameters for each feature and passes them to the modeling system for instantiations. Tolerances and surface finish allow the system to derive manufacturing implications used by the designer to review the design. The physical parameters, in addition to the processing information, lead to an integrated model which may be used by both the designer and the manufacturing personnel. This procedure may be invoked at any level of the design process and contribute to a final manufacturable design. The philosophy employed in the development of this work is to define manufacturing features as instances of generic ones with specific properties and processing methods. The design features obtain their geometric superclasses from a commercially available package of solid primitives thus allowing for the part to be graphically displayed.