面向概念设计的扩展功能建模方法

Extended Product Function Modeling for Conceptual Design

在功能描述方法分析的基础上,提出一种对功能进行扩展建模的方法。建立扩展功能基模型及其基于本体的描述策略;提出表征功能之间关联的扩展功能关联模型,包括功能的逻辑关系模型、语义关系模型以及组合关系模型;提出建立扩展功能结构聚合单元的构想,这种聚合单元是一个不考虑具体的结构形式,而抽取出功能上的本质特征,集功能与概念原理结构特征于一体的强连接结构集合,这种聚合单元形式的引入,避免功构映射过程中功能关联图出现组合爆炸,同时也避免了在概念设计阶段使用常规机构而过早地限制住产品结构形式的缺陷。在此基础上,从功能单元可解性的判定、功能空间的正向扩展规则及逆向扩展规则三个方面给出功能推理的基本策略。通过实例描述扩展功能建模方法的应用以及引入扩展功能模型的有效性。

After systematic analysis of function description methods, an extended function modeling strategy for product conceptual design is proposed. The extended functional basis model as well as its ontology representation strategy is given. The function-connecting model including the logic relationship model, the semantic relationship model and the composition relationship model is established. The idea of introducing extended function structure units into conceptual design stage is proposed. The proposed function structure units are strongly connected parts aggregations, which are obtained by extracting the essential characteristics of parts regardless of their concrete structures. The combinatorial explosion of function-connecting graph in the process of function-structure mapping can be avoided by using those units, as well, those defects which are caused by restricting the product structure too early by the use of conventional structure during conceptual design process can be eliminated. The basic principles for function reasoning are proposed, in which three aspects are involved, they are principles for the solvability of functional unit, positive and reverse rules for functional space expansion. A design example is used to demonstrate the successful and effective application of the proposed function representation method in the conceptual design stage.