Laser Tracker Test Facility at SLAC
Georg Gassner
Robert Ruland, SLAC
February, 2008
Introduction
Rotary Table Calibration
Laser Tracker Investigation
ADM Tests
Conclusion
February, 2008
IWAA08
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Introduction
Particle Physics experiments at
SLAC require high accuracy
positioning, e. g. 100 µm over a
distance of 140 m or 25 µm in a
7 x 10 x 3 meter room
Realization -> Laser Tracker
Measurements
Rotary calibration table (Kugler
GmbH) providing an accuracy of
better than 0.2 arcsec
Interferometer bench
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Rotary Table
Renishaw Signum RESM angle encoder system
1 arcsec graduation accuracy
0.01 arcsec resolution
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Calibration of the rotary table (1)
Rosette technique
calibrate precision
polygon prisms
sum of the angles
measured must result
in 360 degrees
Moeller-Wedel
electronic
autocollimator
(0.1arcsec accuracy,
0.05arcsec
reproducibility)
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Calibration of the rotary table (2)
Derived Technique
set the fixture with the
mirrors in a way that
mirror ‘a’ is in line with
autocollimator ‘a’
rotate the table
together with the
fixture until mirror ‘b’ is
in line with
autocollimator ‘b’
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Calibration of the rotary table (3)
Absolute value of an
angle between two
positions of the
rotary table can be
determined with
±0.2 arcsec std.
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Laser Tracker Horizontal Angle
Measurement System Investigation
Test Setup
mirror as a target for
laser tracker
parallelism of the
two rotation axes
axial displacement
of the rotation axes
Mirror
Faro Laser
Tracker
Rotary
table
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Comparison SMR vs. SMM
Test of Mirror
(SMM) and
Retroreflector
(SMR)
Only small
deviations can be
found
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Calibration Results
Two calibration runs with
Faro Laser Tracker Xi
February, 2008
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Two calibration runs with
Faro Laser Tracker Xi V2
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
ADM Calibration on Interferometer
Bench
Calibration of the scale factor of the ADM in the
field.
Tests of the general performance and tests to
detect malfunctions in the laboratory.
Carriage
•
Horizontal Bench
Laser Tracker
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Interferomete
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Calibration Results
Calibration run with
Faro Laser Tracker Xi
February, 2008
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Calibration runs with
Faro Laser Tracker Xi V2
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
Conclusion
Rotary table - absolute angle accuracy < 0.2
arcsec
Rotary table to test any horizontal angle
measurement instrument
Faro laser trackers angle measurement system
deviations stable and correctible
With corrections, angle accuracies of 1 arcsec are
possible.
Test of the ADM showed its usability as a
replacement for the interferometer mode
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu
End of Presentation
February, 2008
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G. Gassner, R. Ruland
gassner@slac.stanford.edu