运动复合机构创新设计的商空间模型及计算机化方法

The highest tasks of theory of mechanism are to reveal combination principles of mechanical structure, and provide basic theories and efficient approaches for mechanical design and product innovation. To the question that some computer-based conceptual design approaches, such as function-based synthesis and motion-based synthesis, can not guarantee new innovative conceptual design results to be generated, and that the kinematic relations and time and/or spatial compatibilities among different kinematic behaviours have not been well regarded, based on the hierarchical model and the theory of field synthesis of the quotient space theory, a creative design model for kinematic composite mechanisms is set up mathematically. The top-to-down diverging rules for generating the new functional working principles are constructed with the aid of attribute functions and structure functions in the function layer. Considering the basic mechanism of multifunctional attributes, and taking the time and spatial sequences among kinematic behaviours of basic mechanisms as constraints, the down-to-top kinematic behaviour clustering rules of basic mechanisms are written down based on theory of field synthesis of the quotient space. Through the rules-based divergent innovation processes both in the function layer and in the structure layer, the mechanism schemes with coordinating kinematic behaviours each other, and simpler structures, and without time and space interferences are dug out. Then, with the set of behaviour fragments to describe the functional requirements of plane multi-linkages, and with revolute pairs to replace all kinds of kinematic pairs in the mechanism scheme, the functional synthesis approach for the plane mechanisms with multi-DoF and multi-linkages is given based on the function synthesis approach. This study has a great theoretical merit in automatical creative design of combined mechanisms, and in functional synthesis of plane multi-linkages.

机构学最高任务是揭示机械的结构组成原理，为现代机械的设计、发明提供系统的基础理论与实用方法。针对现有计算机化功能综合法和运动综合法不能有效支持机构方案创新，没有考虑各运动行为之间的时间、空间协调性等问题，基于商空间分层递阶与合成理论，将创成法嵌入到功能综合法之中，建立运动复合机构创新设计商空间模型。以商属性和商结构构造自顶向下的功能作用原理创成规则；考虑基本机构的多功能属性，将基本机构的连接、时序等关系作为约束，构造自底向上的基本机构运动行为聚类规则。通过功能层和结构层基于规则的发散，创成充分发挥基本机构多功能行为潜能、运动行为有机协同的机构巧妙组合方案。在此基础上，采用行为片段集描述平面多杆机构综合的功能需求，基于嵌入创成法的功能综合法，解决平面复杂连杆机构综合难题。该研究对于促进组合机构创新设计理论与平面连杆机构综合理论的发展，促进包装机械等产业的升级换代，具有重要的理论价值和应用价值

针对现有计算机化功能综合法不能有效支持机构方案创新，没有考虑各运动行为之间的时间、空间协调性等问题，本课题基于商空间分层递阶与合成理论，将创成法嵌入到功能综合法之中，建立运动复合机构创新设计商空间模型，取得的主要研究进展为：将FBS 模型中的功能-结构直接匹配过程，用两个自底向上的功能重组与结构聚类重构过程替代，形成不依赖于人类专家匹配推理知识的功能-结构匹配模型，在充分拓展功能层创新空间的基础上，通过结构层创新，进一步提高创成方案的新颖性。基于该模型，能够获得功能层优化、时间与空间连续有序的功能-结构匹配方案，用少量机构巧妙组合满足复杂设计功能需求，得到创新性显著优于人类专家的设计方案。受实用机构知识库构建工作量巨大，以及三维匹配技术瓶颈的制约，实用机构创新设计自动化平台没有如期完成，需要继续构建。