3D Vision Based Calibration Approach for Robotic Laser Surfacing Applications

This paper introduces an integrated approach to calibration and optical measurement processing in the area of robotic 3D vision. The target robotic work-cell consists of a 6-axis industrial manipulator extended by a linear rail and a 2-axis positioner, a color 3D camera and a laser surfacing equipment as the process technology. We have developed a hybrid method for the detection of the calibration checkerboard based on sequential processing of the 2D color image and the 3D point cloud data. This method is further used for both the calibration of the 3D color camera as the robot’s tool and for the calibration of the two-axis servo positioner as the robot’s external coordinate frame. The resulting calibrations will be used for precise detection and positiong of the workpiece during the process of 3D scanning and successive laser surface modification. The resulting precision of the calibration techniques is verified by several experiments.