Design optimization of industrial robot arm to minimize redundant weight

Abstract

In industrial robots, projected torque increases depending on the extending reach length and payload. This requires selection of powerful motors particularly on the second axis. Since arm rigidity becomes more important as the expected positioning precision increases, less flexible materials are used. Therefore, during operation conditions, 70% of motor’s energy is used for redundant weight. In this study, analyses conducted on five different robotic arms belong to different brands. Arm’s payload distribution in terms of region and amount is examined, alternative designs are analysed and compared with each other. Geometry and materials are changed in alternative designs. In this way, redundant weight is minimized (without increasing the share amount) at the same positioning precision. Results of this study demonstrated a 10% decrease in inert payloads. Keywords: Robot arm optimization, Industrial robot, Finite element method (FEM)