研究了三维工件模型的定位特征识别与分析,以及定位方案的自动推理算法。基于规则推理简化了模型,提取了候选定位特征面集,并构造了特征面的层次储存模型。结合综合评价规格化理论和标准离差法理论实现了基准选取影响因素重要性比较的定量化,并基于层次分析法实现了多层次定位基准的排序优化。通过层次分析法的总排序得到候选定位基准相对于最优定位基准目标的组合权向量,从而得到最优定位方案。实例验证说明,该算法是可行且符合实际装夹的。
The locating feature recognition,analyses of three-dimensional model of the workpiece and automatic reasoning algorithms to locating scheme were studied.Model was simplified and the candidate locating features set were extracted based on rule-based reasoning and a hierarchical storage model of feature faces was proposed.Comprehensive evaluation normalized theory and standard deviation method theory were combined to achieve the quantitative comparison of importance of selected factors.The sorting and optimization of the multi-level positioning reference was achieved based on AHP,so that the combination weight vector of the candidate locating reference related to the optimal locating reference and the optimal locating scheme could be got through total sort by AHP.Finally,an example was provided to prove that the method of proposed jig and fixture planning is feasible and realistic.