Calibration of a Six-Axis Robot for GNSS Antenna Phase Center Estimation

Abstract

We show that the scatter of the coordinates of the tool of an uncalibrated KUKA model AGILUS KR 6 R900 sixx lies between 0.5 and 0.7 mm if the same point is approached several times with different tool orientations. To use the robot for global navigation satellite system (GNSS) antenna calibration, the standard deviation of the coordinates must lie below 0.1 mm. We developed a calibration procedure based on the optical microtriangulation system QDaedalus and a kinematic model of the robot. The proposed calibration is easy to carry out and highly automatic. Several measurement campaigns including a validation demonstrated that the calibration reduces the standard deviation of the coordinates to below 0.1 mm, making the robot suitable for use in GNSS antenna calibrations.