Calibration of Robot Manipulator and Hand-eye Using RGB Camera

This paper proposes a robot manipulator and hand–eye kinematic calibration method using an RGB camera attached to an end effector. For in-hand configuration, sensing objects with the camera allows for simultaneous kinematic calibration of the manipulator and hand–eye calibration, which is more effective than performing them separately. Thus, the camera measures the chessboard’s 2D corners at different robot arm postures. These corners are reprojected to all images, and a calibration is performed with a bundle adjustment method by reducing 2D reprojection errors. Additionally, the chessboard is placed at multiple positions so that the manipulator can have any posture without limitation. The transformation between chessboard positions is included in the optimization process. This method is validated through exploratory experiments, with results compared to a laser tracker, demonstrating its effectiveness.