Abstract: Selective Compliance Assembly Robot Arm (SCARA) runs fast with high repeated positioning precision in the horizontal plane.So adopts the method of modal analysis and topology optimization,in order optimizing the mechanical structure and reducing the weight of the SCARA robot.First,the SCARA robot arm was created with Solidworks software,then transmitted into finite element analysis software ANSYS Workbench for static analysis and modal analysis—as a result of the analysis,the first six order natural frequencies and vibration modes were obtained.Thirdly,to come up with the optimization direction of removing the arm’s material,the topology optimization method was used,and in the help with this method,the optimal structure of the arm was redesigned and the modal parameters of the optimized structure were calculated.Finally,by comparing the results from modal parameters before and after optimization, proved the fact that the optimized structure do well in reducing the arm’s weight and improving the arm’s mechanical properties.

Key words: arm, modal analysis, SCARA robot, topology optimizat