多准则模糊关联的机械产品关键元动作识别

Key meta-action identification for mechanical product with multi-criteria fuzzy association

关键零件作为复杂机械产品的核心,对实现产品功能具有重要作用。然而,产品中零件数目庞大且具有耦合关系,导致识别关键零件十分困难。为实现产品关键单元的识别,从元动作出发,提出了一种面向复杂机械产品的多准则模糊关联综合评价的关键元动作识别方法。首先,利用“功能—运动—动作(fuction-montion-action,FMA)”的分解方法将复杂机械产品分解至最小运动单元——元动作;其次,基于不同元动作之间的运动和结构关系建立三角模糊评价矩阵,将证据理论与模糊关系结合,提出了模糊证据理论算法,实现了元动作之间不同关联信息的融合,解决了元动作之间信息模糊或缺失的问题,并在此基础上利用三角模糊数可能度关系的指标权重确定方法实现对元动作重要度的排序;最后,以国产某型号数控加工中心的转台为例,验证了该方法的合理性与有效性。研究表明:FMA分解方法从运动角度出发,可以简化整机的分解过程,有效表征产品零件的运动关系;从元动作的结构和运动关系分析元动作之间的相关性可以更好地研究元动作之间的耦合性;将证据理论带入模糊关系中进行不同元动作之间的关联信息融合,可以解决信息模糊问题。通过对元动作重要度的排序识别关键元动作,为后续对元动作单元的研究奠定了基础。

As the core of complex mechanical product, key parts play an important role in realizing product functions. However, it is very difficult to identify key parts because of the large number of parts and their coupling relationship. In order to realize the identification of key units of product, a method of key meta-action identification for complex mechanical product based on multi-criteria fuzzy association comprehensive evaluation was proposed from the perspective of meta-action.Firstly, the complex mechanical product was decomposed into the smallest motion unit-meta-action, by using the decomposition method of fuction-montion-action(FMA);secondly, a triangular fuzzy evaluation matrix was established based on the motion and structure relationship between different metaactions. Combining evidence theory and fuzzy relationship, a fuzzy evidence theory algorithm was proposed to achieve the fusion of different associated information between meta-actions, solve the problem of information ambiguity or missing between meta-actions. On this basis, the ranking of the importance of meta-actions was realized by using the method of determining the index weight of the possible degree relationship of triangular fuzzy numbers;finally, taking the turntable of a domestic NC(numerical control)machining center as an example, the rationality and effectiveness of the method were verified. The research showed that FMA decomposition method could simplify the decomposition process of the whole machine from the perspective of motion, and effectively characterize the motion relationship of product parts;the coupling between meta-actions could be better studied by analyzing the association between meta-actions from the structure and motion relationship of meta-actions;the problem of information fuzziness could be solved by introducing evidence theory into fuzzy relations to fuse the related information between different meta-actions. By sorting the importance of meta-actions, key meta-actions were identified, which laid a foundation for the subsequent research on meta-action units.