基于案例推理的夹具设计案例表示与检索

发布时间：2019-04-25 13:19

【摘要】：夹具具有夹持工件并精确定位的重要作用。由于夹具设计关联因素诸多,过程复杂,设计方案很大程度依赖于设计者经验,最近发展的基于案例推理的夹具设计方法可一定程度上缓解对个人经验的依赖性,但此类设计方法大多仅以工件的几何形状为案例表示和检索依据,影响推理系统的检索效率及准确度,其有效性和实用性也因此减弱。鉴于此,建立了一种夹具设计案例特征表示的新型检索机制,该模型不仅包含工件几何形状,还包含工件材料、加工工艺和其他功能要求等因素,采用统一建模语言(Unified modeling language,UML)面向对象的表示方式实现特征信息存储的结构化和模块化,采用几何形状和位置拓扑关系并行检索的算法,该算法主要通过搜索节点对应约束的最大相似连通子图以确定零件的几何特征相似度,并给出其他影响因素相关的相似度公式。具体实例说明该新型检索模型的有效性和实用性。
[Abstract]:The fixture has the important function of clamping the workpiece and locating the workpiece accurately. Because there are many correlative factors and complicated process in fixture design, the design scheme depends on the experience of designer to a great extent, the recently developed case-based reasoning method of fixture design can alleviate the dependence on personal experience to a certain extent. However, most of these design methods are based on the geometric shape of the workpiece, which affects the retrieval efficiency and accuracy of the reasoning system, so the effectiveness and practicability of the design method are weakened. In view of this, a new retrieval mechanism for feature representation of fixture design case is established. The model includes not only the geometric shape of workpiece, but also the factors of workpiece material, machining technology and other functional requirements. The unified modeling language (Unified modeling language,) is adopted. UML (object-oriented representation) realizes the structure and modularization of feature information storage, and adopts the parallel retrieval algorithm of geometry shape and position topology relation. The algorithm mainly searches the maximum similarity connected subgraph of the corresponding constraints of nodes to determine the geometric feature similarity of parts, and gives the similarity formulas related to other influencing factors. An example is given to illustrate the effectiveness and practicability of the new retrieval model.
【作者单位】：东南大学机械工程学院;
【基金】：国家自然科学基金(51105075,51405080) 中国博士后科学基金(2014M561546)资助项目
【分类号】：TG75

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