Optimization of Comprehensive Stiffness Performance Index for Industrial Robot in Milling Process

Abstract

Low stiffness of serial robot is the main factor limiting its application in milling task. In order to improve the stiffness characteristics of the robot, the stiffness model is established based on the kinematics model and Jacobian matrix. Then, for the milling task, the milling process is analyzed and the cutting force model is introduced. Based on that, the stiffness model of the robot is further analyzed and the stiffness performance index is proposed. Condition number is introduced to measure the dexterity of the robot for avoiding the singular posture during the milling process. A comprehensive stiffness performance optimization model was established, and the posture of the robot in milling process is optimized. Finally, the posture with optimal stiffness are obtained.