Estimation of Uncertainty in Three Dimensional Coordinate Measurement by Comparison with Calibrated Points

This paper details a method of estimating the uncertainty of dimensional measurement for a three dimensional coordinate measurement machine. An experimental procedure was developed to compare three dimensional coordinate measurements with calibrated reference points. The reference standard used to calibrate these reference points was a fringe counting interferometer with a multilateration like technique employed to establish three dimensional coordinates. This is an extension of the established technique of comparing measured lengths with calibrated lengths. Specifically a distributed coordinate measurement device was tested which consisted of a network of Rotary-Laser Automatic Theodolites (R-LATs), this system is known commercially as indoor GPS (iGPS). The method was found to be practical and was used to estimate that the uncertainty of measurement for the basic iGPS system is approximately 1 mm at a 95% confidence level.

Authors

J E Muelaner, Z Wang, O Martin, J Jamshidi, P G Maropoulos

Department of Mechanical Engineering, The University of Bath, Bath, UK

Published in

Measurement Science and Technology, 2010

Accepted for Publication on 16/12/09

Volume and page number information

21 () 025106

Notes

Results given in this paper were obtained using the original Workspace software
and a typical 4 transmitter setup. Further testing has shown that uncertainty may
be reduced by using newer software versions, and more complicated configurations
with more hardware.

DOI

10.1088/0957-0233/21/2/025106

Download

Official URL:

http://www.iop.org/EJ/abstract/0957-0233/21/2/025106/

References

1. Flack D 2001 Measurement Good Practice Guide No. 42: Q2
   CMM Verification (National Physical Laboratory)
2. Muelaner J E, Wang Z, Jamshidi J, Maropoulos P G,
   Mileham A R, Hughes E B and Forbes A B 2008
   Uncertainty of angle measurement for a rotary-laser
   automatic theodolite (R-LAT) Proc. Inst. Mech. Eng. B
   223 217–29
3. Hedges T M, Takagi H, Pratt T and Sobel M J 2003 Position Q3
   measurement system and method using cone math
   calibration US Patent 6535282
4. Triggs B, Mclauchlan P, Hartley R and Fitzgibbon A 1999
   Bundle adjustment—a modern synthesis. Vision
   algorithms: theory and practice International Workshop on
   Vision Algorithms (Corfu, Greece)
5. BSI 2002 Geometrical product specifications Q4
   (GPS)—acceptance and reverification tests for coordinate
   measuring machines (CMM)—part 2: CMMs used for
   measuring size BS EN ISO (10360-22002)
6. ASME 2006 Performance evaluation of laser-based spherical
   coordinate measurement systems (B89.4.192006)
7. Lau K, Hocken R and Haight W 1985 Automatic laser
   tracking interferometer system for robot metrology Proc.
   CIRP—Precision Engineering Conference (Interlaken,
   Switzerland) pp 100–2
8. Richard S and Kendall B 2006 Chirped coherent laser radar
   system and method
9. VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik
   2002 Optical 3D measuring systems—imaging systems
   with point-by-point probing VDI/VDE 2634 part 2
10. Anchini R, Di Leo G, Liguori C, Paolillo A, Pietrosanto A
    and Strazzullo G 2007 Metrological verification of 3D
    scanners: a preliminary approach SPIE –Int. Soc.Opt. Eng.
    (Bellingham WA, WA , United States, San Jose, CA, United
    States) p 649108, 98227–0010
11. Schwenke H, Franke M, Hannaford J and Kunzmann H 2005
    Error mapping of CMMs and machine tools by a single
    tracking interferometer CIRP Ann. –Manuf. Technol.
    54 475–8
12. BSI. 1995 General Metrology—part 3: Guide to the
    Expression of Uncertainty in Measurement (GUM) (PD
    6461–31995)
13. Estler W T, Edmundson K L, Peggs G N and Parker D H 2002
    Large-scale metrology—an update CIRP Ann. – Manuf.
    Technol. 51 587–609
14. Calkins J M 2002 Quantifying coordinate uncertainty fields in
    coupled spatial measurement systems mechanical
    engineering Virginia Polytechnic Institute and State
    University, Blacksburg p 226