关联工艺引导的型腔类零件局部结构检索方法
Associated Machining Process-Guided Subpart Retrieval Approach of Parts with Pockets for Machining Process Reuse
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摘要: 针对已有的基于内容的三维CAD模型检索技术难以保证检索结果关联工艺的可重用性,需要设计人员进一步甄别其重用价值的问题,提出一种关联工艺引导的型腔类零件局部结构检索方法,以从基于制造特征的结构化工艺数据中查找关联工艺可重用的相似三维几何.首先建立特征关联工艺参数化驱动模型,从特征加工几何、加工精度、刀具几何角度揭示特征实例关联工艺的参数化驱动特性;然后以特征实例关联工艺为参考,建立基于中轴转换的特征相似性评价模型;最后提出基于子图同构的相似局部结构提取算法,并且计算相匹配局部结构之间的相似度.在CATIA平台下开发了原型系统,并验证了文中方法的有效性.Abstract: To deal with the issue of the reusability of the retrieval results difficult to be ensured by existing methods,which requires engineers to further determine their reuse value,an associated machining process-guided subpart retrieval approach for parts with pockets is proposed to search the similar 3D geometry with reusable associated machining process in structured machining process data.First,a parameter-driven model for the feature’s associated machining process is established to reveal the machining process parameter-driven characteristic of similar feature from the perspective of machining geometry,machining precision and cutter geometry.Then,a feature similarity assessment approach merging with the associated machining process of similar feature is presented using the pocket’s medial axis transform.Finally,the subpart extraction method based on sub-graph isomorphism is presented to calculate the similarity between matched features.A prototype system has been developed to verify the effectiveness of the proposed approach.