Abstract: As the most complex and abstract link in the whole fixture design,the planning of fixture layout scheme directly affects the machining quality,production efficiency and manufacturing cost of workpieces.Based on the previous research of analytic hierarchy process and positioning certainty based workpiece positioning scheme planning algorithm,a clamping scheme design method based on Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) and Multi-objective Evolutionary Algorithm Based on Decomposition (MOEA/D) was further established.By establishing a hierarchical model for selecting clamping surfaces,a TOPSIS method for calculating the closeness of candidate clamping surfaces was proposed.Considering the dual factors of workpiece stability and clamping deformation,a multi-objective optimization model of clamping layout satisfying both clamping stage and machining stage was established.Based on the positive decomposition of multi-objective function by Tchebycheff method,the MOEA/D solution method of multi-objective optimization model of clamping scheme was constructed.The clamping layout schemes were designed to bore a hole at the irregular workpiece by using the established method.Comparison of the design results with the existing fixture structure scheme showed that they were completely consistent with each other.The clamping scheme planning algorithm based on TOPSIS and MOEA/D was easy to program.It could not only reasonably plan the clamping scheme for any workpiece,but also provide theoretical support for the development of computer-aided fixture design system.

Key words: technique for order preference by similarity to an ideal solution , fixturing layout, clamping surface, multi-objective evolutionary algorithm based on decomposition, fixturing stability

摘要： 作为整个夹具设计中最为复杂和抽象的环节,装夹布局方案的规划直接影响着工件的加工质量、生产效率和制造成本。为此,在前期关于基于层次分析法与定位确定性的工件定位方案规划算法的研究基础上,进一步建立了一种基于逼近理想解排序法(TOPSIS)和基于分解的多目标进化算法(MOEA/D)的夹紧方案设计方法。首先,通过建立选择夹紧表面的层次结构模型,提出了计算候选夹紧表面贴近度的TOPSIS方法。其次,考虑到工件稳定性和装夹变形的双重因素,建立了同时满足夹紧阶段和加工阶段的装夹布局多目标优化模型,在利用切比雪夫方法对多目标函数进行正对性分解的基础上,构建了夹紧方案多目标优化模型的MOEA/D求解方法。最后,利用建立的方法设计出非规则零件钻孔用的装夹布局方案,并与现有夹具结构方案进行对比和分析,结果表明设计方案与现有方案完全吻合。基于TOPSIS和MOEA/D的夹紧方案规划算法易于编程实现,既能为任意工件合理地规划出夹紧方案,也能为计算机辅助夹具设计系统的开发提供理论支持。

关键词: 基于逼近理想解排序法, 装夹布局, 夹紧表面, 基于分解的多目标进化算法, 装夹稳定性