Hand-Eye Calibration Method for Manipulator and RGB-D Camera Using 3D-Printed Ball

Traditional hand-eye calibration methods are practically inappropriate for RGB-D cameras, because that the RGB optical center and the depth optical center are not in the same location, and the depth-image is of poor measuring accuracy, low resolution, and no RGB or texture information. A hand-eye calibration method for robotic manipulator and RGB-D cameras using a simple low-cost 3D-printed ball as the calibration object is proposed. Only 3D position measurements of the calibration object are used, which avoids the inconvenience and inaccuracy of orientation measurements. A closed-form solution and an iterative optimal solution are formulated. Results of 100 simulations suggest that the calibration accuracy depends on the measuring accuracy of the RGB-D camera itself, the closed-form solution does not need time alignment between the manipulator and the RGB-D camera, and the calibration accuracy of the iterative optimal solution improves a little bit, while the maximum and variance errors are very stable. Finally, 7-DOF KUKA ⅡWA robot and the Kinect sensor are used to perform hand-eye calibration experiments, and the results are consistent with the simulations. In conclusion, the proposed method is simple and reliable, and can realize the quickly-deployable hand-eye calibration for robotic manipulator and RGB-D cameras.