Research on Calibration Method of Joint Reduction Ratio for Industrial Robot Considering Dynamic Factors

The increasing application of industrial robots in advanced manufacturing demands higher pose and trajectory accuracy. Motion parameter identification and calibration are effective methods to enhance operational precision. This study addresses the angle error in industrial robot joints by introducing a novel joint reduction ratio calibration strategy that incorporates dynamic factors. The research primarily investigates the impact of rotational inertia and speed on error patterns. Experimental methods were employed to examine the distribution of joint angle errors in the first and second joints, which are significantly influenced by the robot's posture, under varying rotational inertias and joint speeds. Further analysis from the perspectives of servo follow-up error and reducer structure elucidates the variation mechanism of the reduction ratio under different conditions. A joint transmission error compensation method based on variable reduction ratio is integrated into the motion controller. Results indicate that the proposed calibration strategy reduces the rotational angle errors of joints 1 and 2 to less than 0.01° and 0.02°, respectively, under different rotational inertias and speeds. This approach significantly improves compensated joint transmission errors, providing robust technical support for enhancing the highprecision control of industrial robots.