Compensation of SCARA Robot Positioning Error using Stereo Camera

摘要

SCARA robots are used in the assembly tasks because of its excellent characteristics. The repeatability of the assembly robot is about 0.02mm in average but the absolute positioning accuracy is not so good. The lack of absolute positioning ability causes the obstruction of the effective off line teaching by CAD. To improve the absolute positioning accuracy, machine vision system especially stereo camera system is useful. In this study, the 3D error model of the SCARA type robot is proposed and calibration method of the error parameters using stereo CCD camera measurement is presented. The positioning accuracy is improved up to 0.12mm in the root mean square and less than 0.20mm in maximum value.