Inspection planning control of laser guided measurement robot

Laser tracking system (LTS) is a portable 3D large size coordinate measuring machines (CMM), it measures 3D coordinates with laser beam by following a spherically mounted retro-reflector (SMR) with the advantages of broad range, high speed and high accuracy. However, the current inspecting task of LTS is performed manually to move SMR along the different position on the surface of a given part and measured with the trial-and-error approach. In order to perform LTS more efficiently and automatically, this paper has developed a laser guided measurement robot (LGMR) based on a new theory ldquolaser beam moving and SMR trackingrdquo instead of the traditional method ldquoSMR moving and laser beam trackingrdquo. A systematic control algorithm of generating optimal inspection planning based on CAD-directed model is proposed for LGMR to inspect free-form surfaces. The control algorithm not only generates the movement orientation, position and optimal distance for LGMR, but also a consistent and efficient inspection process that can avoid the unnecessary trials in manual operations and reduce inaccuracy and inconsistency due to different operators. The experiment result has demonstrated that the inspection planning control algorithm can be integrated to the LGMR and generated automated scanning process under automaticity and accuracy constraints.