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

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