基于设计特征模型的加工特征映射技术

为了实现数控编程过程中能够自动确定加工区域,对基于特征设计系统构建产品模型的方法、产品信息模型、信息模型间的关联关系、飞机结构件加工特征定义分类、设计特征与加工特征间的内在关系进行了深入的研究,提出了基于设计特征模型映射加工特征的方法.该方法通过遍历特征设计树,判断特征间的关系,查询特征组成面信息,从而构建出特征属性邻接图,进而采用基于图匹配的特征识别方法得到加工特征,并提取加工特征信息.该方法压缩了图匹配空间,大大提高了特征识别的速度,应用此方法实现了飞机壁板类零件的特征识别.

Techniques of machining feature mapping from design-by-feature model

To pick up the machined area automatically in numerical control programming,a new methodology for recognizing machining features from a design feature model was presented based on the study about the product modeling method in the design-by-feature systems,product information models(geometric and topological information model,feature relationship model which usually named feature specification tree),the relationships between these two information models,the machining feature class definition in aircraft structure parts,interacting relationships between design features and machining features.By touring the feature specification tree,judging the features' relationships and querying the feature's surfaces,the feature mapping method from a design-by-feature model constructed the feature attribute adjacency graph(FAAG) and recognized the machining features by matching boundary patterns in the local feature area,then extracted the machined information such as the machined area,the avoided area,the tool approach direction.It can be used to recognize the aircraft wainscots parts.