Multiple Laser Tracker Synchronization for Vibration Analysis

Publication Details

Abstract

Measuring the mechanical coupling and rigidity of a large apparatus presents unique challenges for 3D metrology. In this case, the motion of well-separated points attached to a rotor blade must be rapidly and repeatedly measured, and the resulting data synchronized. This article describes the methodology and results for the mechanical coupling test of the magnetic field mapping system (FMS) for the Muon-to-Electron Conversion Experiment (Mu2e) at Fermi National Accelerator Laboratory (Fermilab). Three laser trackers (two Radians and one T3, all from Automated Precision Inc. of Rockville, MD) simultaneously measured the position of three cylindrical corner-cube reflectors mounted on the FMS, both as the system was in motion and after coming to rest. The laser trackers took measurements at 83 Hz for the T3 and 100 Hz for the Radians, with fine spatial resolution, resulting in more than 20,000 points measured per instrument in the observation cycle. The laser tracker hardware and available software were unable to synchronize the three independent data streams directly during the measurement process. Therefore, a custom software program was developed to perform this synchronization of the data sequences during post-processing using features of the targets’ motion common to all three fiducial locations.