Abstract: Aiming at the selective assembly problem for mechanical product with multi-objective assembly function,a method based on strong-weak Pareto and genetic algorithm was proposed.An unified selective assembly information model oriented to 3D space was established based on the analysis of mechanical product's assembly characteristics,with which a comprehensive optimization model taking the assembly precision and assembly yield into consideration was constructed.A coding method taking tolerance item as unit was used and a comprehensive evaluation rule describing important relationship between assembly functions by concepts of strong-weak Pareto and crowed degree based on weighting coefficient was put forward.By considering the order of measured data from different tolerance items,a multi-objective genetic algorithm under the rule of comprehensive evaluation was used to achieve the high efficiency and best match solution in the process of selective assembly.A prototype system was developed and an example was tested to verify the feasibility of proposed approach.

Key words: assembly precision, selective assembly, strong-weak Pareto, comprehensive evaluation, multi-objective evolution algorithm

摘要： 针对机械产品多质量要求下的选配问题,提出一种基于强弱Pareto和遗传算法的多质量要求下的选择装配方法。对选配问题进行分析,构建了一种面向三维空间多质量要求下的统一选配信息模型,在此基础上考虑装配精度和装配成功率,进而建立了多质量要求下的选配综合优化模型。采用一种以公差项为单元的编码方式,并通过给出质量要求权重系数,提出以强弱Pareto和密集度描述带有主次关系的多目标综合评价规则,在考虑关联约束排序的基础上,利用遗传算法进行多目标的选择装配,实现了带有主次关系的多质量要求下产品的选配优化。设计并开发了原型系统,通过实例验证了该方法的可行性。

关键词: 装配精度, 选择装配, 强弱Pareto, 综合评价, 多目标进化算法