Abstract: In order to improve the efficiency and reliability of industrial robots,the topology optimization design of a certain type of industrial robot′s large arm was conducted. The fuzzy satisfaction variable weight coefficient method combined with the membership function was used to assign the weights coefficient for the multi-objective topology optimization of the large arm,which can remove the human factor in the traditional multi-objective topology optimization. A finite element model of the large arm was established and its correctness was verified by strain measurement experiments and acceleration measurement experiments,dynamics simulation of industrial robots was conducted by Adams software to obtain the force on the big arm under three working conditions,and the single-objective topology optimization design of static stiffness under three working conditions and the first three inherent frequency was performed,then the fuzzy multi-objective topology optimization structure of the large arm was obtained. Based on optimization results the large arm was reconstructed,the stress of the traditional optimized arm increases instead of decreasing under working condition 2,and the magnitude of other sub-objective optimization is not as good as that of the fuzzy multi-objective topology optimization. The large arm optimized with fuzzy multi-objective topology reduces the weight by 12.2 % compared with the original arm,while the stiffness under the three working conditions and the first and the third order natural frequency are all improved to different degrees,proving the optimization method′s effectiveness.

Key words: fuzzy theory, industrial robots, large arm, multi-objective, topology optimization