Geometric Reasoning for Extraction of Manufacturing Features in Iso-Oriented Polyhedrons
Geometric Reasoning for Extraction of Manufacturing Features in Iso-Oriented Polyhedrons
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DOI：
10.1109/34.334388
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发表时间：
1994-11
期刊：
影响因子：
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通讯作者：
Sanjeev N. Trika;R. Kashyap
中科院分区：
文献类型：
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作者：
Sanjeev N. Trika;R. Kashyap
本文研究了从等方位（无斜面）多面体的边界描述中提取加工特征的方法。我们证明，制造我们的特征提取器提出的功能的结果正是在所需的部分，在这方面，该方法是健全和完整的。我们的方法使用面之间的邻接信息来获得特征。这使零件中孤立特征的确定变得简单明了。然而，由于某些面之间的邻接信息丢失，特征的交互造成了困难。我们得到这个丢失的信息，考虑面，当扩展相交其他面形成凹边。导出的面邻接称为虚拟链接。通过增加虚拟链接到物体的腔图，得到物体的特征图，并在该图中对原始图进行子图匹配，得到特征假设。特征假设被认为是有效的，如果对应于它的体积不与所讨论的部分共享;因此，我们通过检查特征体积和部分的正则化交集来验证特征假设。因此，特征验证采用构造性立体几何方法。在Smalltalk-80环境下实现了一个原型系统。>
This paper investigates the extraction of machining features from boundary descriptions of iso-oriented (having no inclined faces) polyhedrons. We prove that manufacturing the features proposed by our feature extractor results exactly in the desired part-in this respect, the approach is both sound and complete. Our method uses the adjacency information between faces to derive the features. This keeps the determination of isolated features in a part straightforward. However, interaction of features creates difficulties since the adjacency information between some faces is lost. We derive this lost information by considering faces that when extended intersect other faces to form concave edges. The derived face adjacencies are termed virtual links. Augmenting the virtual links to the cavity graph of the object leads to its feature graph, and subgraph matching of primitive graphs in this graph results in feature hypotheses. A feature hypothesis is considered valid if the volume corresponding to it is not shared with the part in question; therefore, we verify the feature hypotheses by checking the regularized intersection of the feature volume and the part. Thus, feature verification employs a constructive solid geometry approach. We have implemented a prototype of the system in the Smalltalk-80 environment. >