Rapid coordinate transformation between a robot and a laser tracker

Aiming at transformation between robot coordinate and laser tracker coordinate, a new method combining single axis rotation and tooldata of the robot is proposed. A target ball is fixed at the end of the robot and its center point coordinate is measured by a laser tracker in real-time. The circular locus generated from the robot single axis rotation is spatial circle fitted; the unit normal vector is obtained and the rotation matrix is calculated. Then the coordinate offset between original target ball center and the default tool point of the robot is used to calculate the translation vector. Experiment results show that the measured RMS errors for X, Y and Z coordinates after transformation are 0.216 mm, 0.111 mm and 0.157 mm, respectively.