基于语义网络的方案设计过程表达与推理

从基于机械运动方案设计的表达方法必须能支持概念设计全过程的思想出发，提出计算机辅助概念设计系统必须能够表达设计方案、产生方案、产生多个方案和确定最优方案．根据方案表达方法应具备的基本功能要求，选用语义网络技术表达设计方案过程、工艺动作、机构及其相互间的关系，通过对设计方案中机构时间配合及其影响的表达和调整实现了方案设计运动循环图表达的计算机辅助化．利用基于语义网络表示的不确定性推理技术构造待求问题的语义网络片断，通过已有设计实例与设计要求的属性值与属性值、属性值与属性值域、属性值域与属性值域三者的匹配比较构造贴近度计算公式，并对工业平缝机中的挑线机构进行了机构选型．实例证明了击模型的正确、实用性．

Process Presentation and Reasoning of Scheme Design Based on Semantic Network Method

The presentation method of mechanical kinematic scheme should support the whole process of conceptual design. To meet the requirement, a computer aided conceptual design system must represent a scheme, generate a scheme, or scheme variants and evaluate the variants. Based on the demand of basic functions of scheme representation methods, a semantic network method is selected to represent process level, action level, mechanism level and the relationship among them. Computer aided motion cycle chart exploration can be realized by representation and adjustment of the mechanism time coordination and its effect on the design scheme. The uncertain reasoning technology based on semantic network is applied to construct a semantic network fragment. The closeness degree formula is determined by matching and comparison between value to value, value to range, range to range of the design cases and design requirements. It is applied in the mechanism types selection of needle driving mechanism of industrial sewing mechanism, and the application indicates it is correct, useful and advanced.