基于事例推理是解决面向装配的设计和装配工艺规划问题的有效方法,装配体检索是应用此方法的关键步骤.为此提出一种基于子图同构与事例匹配的装配体局部结构相似性分析方法.该方法将装配体零件间的装配关系用属性邻接图来表示,通过对装配体中联结关系的定性分类及装配体属性邻接图预处理规则的定义,利用Ullmann算法匹配出相似的装配体图(子图)结构,并给出了装配体局部结构相似度计算公式.最后通过实例验证了文中方法的有效性.
Case based reasoning is an effective method to solve design for assembly and assembly planning problems, while assemblies retrieval and indexing is a primary step to its application. A method of local matching of assembly models is proposed, which is based on subgraph isomorphism and case matching. An attributed adjacency graph is constructed to represent assembly models. The connection relations of assemblies are formally expressed and categorized . The pretreatment rules of the attributed adjacency graph of assemblies are defined. Then, the similar structures of assembly graph(subgraph) are matched by using Ullmann algorithm. And similarity calculation formulae of local matching of assemblies are given. Finally, an example is illustrated to verify the validity of the proposed approach.