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Feature Modeling Based on Topological and Geometrical Constraints for Realizing Designer's Intent

基于拓扑和几何约束的特征建模以实现设计者的意图

基本信息

批准号：
11650159
负责人：
HIGASHI Masatake
金额：
$ 1.98万
依托单位：
Toyota Technological Institute
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

Nowadays, CAD systems with parametric modeling functions are realized. However, efficient product development is not performed because designer's intent which was expressed as constraints and manufacturing information in the engineering drawings is not represented directly in a product model but as a history of commands and dimension values of shapes. Hence our object of this research is to develop functions such as symbolical representation of designer's intent using topological and geometrical constraints along with attribute information, efficient parametric design according to designer's direct indication, and representation and modeling of multiple views for design, manufacture and analysis. To achieve this objective, we have carried out the following research.1. We have developed algorithms which deduce topological constraints considering that geometrical elements with ambiguities caused by numerical calculation are degenerate, obtain consistent constraints according to transitio … More n rules among degenerate states, and make topology of the output solid from the constraints.2. We have introduced a method which describes topological constraints in a feature model from a type of feature and faces of a product where the feature is attached, and which represents geometrical constraints from designer's indication concerning allocation and sizes of the feature. When a parameter is changed, we modify the product shape detecting topological changes. Here, we obtain consistency between a feature model and a geometric model, modifying a feature type and over or under constraints of dimensions.3. We have represented a compound feature using a similar structure as a basic feature in a product model, and enabled users to access a library of compound features on the network by representing them in a XML file. We have also studied algorithms for retrieving resemblant features and protecting the library from registering the same feature type.4. We have developed a method which selects a design parameter and determines its value automatically to change of a product shape according to manufacturing requests (manufacturing constraint). We pick up dimensional parameters which affect the manufacturing constraint using the dependency graph in the geometrical constraint, and select the parameter which has the least influence on the designer's intent according to the attribute information. Then, we obtain the value solving an equation or equations generated from the face data table against the variable of the parameter. Less

目前，具有参数化建模功能的CAD系统已经实现。然而，不能进行有效的产品开发，因为在工程图中被表达为约束和制造信息的设计者的意图没有直接表示在产品模型中，而是表示为命令和形状的尺寸值的历史。因此，本研究的目的是开发功能，如使用拓扑和几何约束沿着与属性信息的符号表示设计师的意图，有效的参数化设计，根据设计师的直接指示，和表示和建模的多个视图的设计，制造和分析。为了实现这一目标，我们进行了以下研究：1.本文提出了一种算法，该算法考虑到由数值计算引起的具有二义性的几何元素是退化的，推导出拓扑约束，并根据变换得到一致的约束， ...更多信息 n规则，并根据约束条件生成输出实体的拓扑结构.我们已经介绍了一种方法，它描述了拓扑约束的特征模型中的一种类型的功能和一个产品的特点是附加的面，并表示几何约束设计师的指示有关的分配和尺寸的功能。当一个参数改变时，我们修改产品的形状检测拓扑变化。在这里，我们获得了特征模型和几何模型之间的一致性，修改了特征类型和尺寸约束.我们已经表示了一个复合功能，使用类似的结构作为产品模型中的基本功能，并使用户能够访问网络上的复合功能库，通过将它们表示在XML文件中。我们还研究了检索相似特征和保护库不注册相同特征类型的算法。我们开发了一种方法，选择一个设计参数，并确定其值自动改变产品的形状，根据制造要求（制造约束）。利用几何约束中的依赖图提取影响制造约束的尺寸参数，并根据属性信息选择对设计意图影响最小的尺寸参数。然后，我们针对参数的变量求解从面部数据表生成的一个或多个方程来获得值。少