Technical Papers & Journals

Multiple Laser Tracker Synchronization for Vibration Analysis

Volume 13, Issue 2

Jana Barker, Charles Wilson, Horst Friedsam

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.

Experimental Evaluation of Leica T-Mac Angular Accuracy

Volume 13, Issue 2

Zheng Wang, Patrick Keogh

The Tracker Machine (T-Mac) control sensor from Leica (Hexagon Manufacturing Intelligence, North Kingstown, RI) is a unique, dynamic, large-volume six degree of freedom (6DOF) metrology system widely used for scanning, probing, and calibration, as well as real-time control of machine tools and robots. It is a hybrid metrology system utilizing both laser tracking and active photogrammetry, where the laser tracker system provides the 3DOF position and the photogrammetry system provides 3DOF orientation. Although there exist international standards for evaluating the accuracy of laser trackers, there appears to be a lack of literature on the assessment of angular accuracy of this type of instrument. This article presents an experimental method of evaluating the T-Mac angular accuracy throughout its measurement range using a precision rotary table. The article describes the setup of the experiment and measurement comparisons at different ranges and orientations of the T-Mac.

CMSC 2018 Presentation - Automated Navy Radar Array Survey with Laser Trackers

Wilvin Crawford, Steve Seiler, Scott Sandwith

Abstract ...

CMSC 2018 Presentation - Technical and Procedural Challenges in the Development of ASTM E3125-17 Documentary Standard

The Dimensional Metrology Group (DMG) at National Institute of Standards & Technology (NIST), along with various other organizations were involved in the development of the ASTM E3125-17 documentary standard for 3D imaging systems.  The ASTM E57...

CMSC 2018 Presentation - Automated Transport and Photogrammetry System (ATAPS)

Photogrammetry is often not utilized for certain measurements because of the time required to target the holes and features that must be captured to complete the measurements.   This paper presents a new process created by Geodetic Systems...

CMSC 2018 Presentation - CMM Automation and Optimization using Model Based Definition

CMM programming is currently a tedious, time consuming, and error prone process which requires the active involvement of a highly skilled quality engineer. The GD&T product requirements need to be manually transcribed into the CMM programming software...

CMSC 2018 Presentation - Automated Laser Rail for ADM Calibration

Paul Nichola

ChallengeExisting processes for calibrating ADM laser trackers involves time consuming practices, manual redundancies and large footprints that inhibit an efficient process for sending laser trackers back into the field where they can be utilized by the...

CMSC 2018 Presentation - Experimental Uncertainty Analysis for Nondestructive Testing of the CSX Wilbur Bridge Using Electronic Distance Measurements to Measure 3-D Coordinates of Cardinal Points

A 154 page report by Moreu and LaFave in 2012 explains unique problems railroad bridge engineers must contend with. The gross weight of cars went from 200,000 pounds to 263,000 pounds in the 1970s, and to 286,000 pounds in 1991. The ratio of live to dead...

CMSC 2018 Presentation - A NEW EXTREME SPORT - METHODS FOR CHARACTERIZING CMM PERFORMANCE

The Dimensional Metrology Group at the National Institute of Standards and Technology (NIST) has developed its suite of ultra-high accuracy Moore M48 coordinate measuring machines (CMM) into the premier 3-axis CMM capability in the world for gauges and...

CMSC 2018 Presentation - Long Duration Photogrammetric Monitoring of Turbine Deformation at High Temporal Frequency

As a non-contact 3D measurement technology, photogrammetry has long been applied in deformation monitoring. Applications have ranged from the measurement of deformation of large-scale engineering structures such as bridges, buildings and dam walls, to...