Error Correction for the Tracking Mirror

Laser guiding measurement robot (LGMR) technology is based on the measurement method "laser beam moving, spherical mounted retro-reflector (SMR) tracking", which uses CAD model to adjust the position and attitude signals of measuring laser beam by controlling the tracking mirror of laser tracker. The beam guides the robot with SMR to the required position to complete the measurement of the objects together with a laser tracker. The tracking mirror mechanism is a very important part in the system. Effects of tracking mirror mechanism geometric errors on measured coordinates and Spherical Mounted Retro-reflector (SMR) alignment errors on sensor reading are investigated. Through error analysis of the proposed model, it is claimed that gimbals axis misalignments and tracking mirror center offset are the key contributor to measuring errors of laser tracker. Intensive experimental studies are conducted to check validity of theoretical results. The results show the measuring accuracy of laser tracker can be increased by 5 times using this model for correction.