ATI Technologies 9105-IFPS-1, Manual

Page: 20 / 71

Manual, F/T Sensor, Data Acquisition (DAQ) Systems
Document #9620-05-DAQ.indd-20
Pinnacle Park • 1031 Goodworth Drive • Apex, NC 27539 • Tel: 919.772.0115 • Fax: 919.772.8259 •
www.ati-ia.com
• Email:
info@ati-ia.com
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3.3 Load Calculation
Calculations must be performed to derive the loads sensed at the transducer. The transducer reports the
loads as composite values that require conversion to values corresponding to the six Cartesian axes. ATI
supplies software to perform these calculations. Both the software and the transducer’s calibration values
can be accessed from the media that accompanies the transducer.
Figure 3.4 shows the calculation required
to convert strain gage data into force and torque data. This method can be used in Matlab, or through other
software that enables manual matrix calculations.
NOTICE:
The CD included with the DAQ system contains extensive help files on its software
that will benefit both the beginner and advanced user. The CD even includes a spreadsheet to
help advanced users with calculations, see the Advanced Techniques section of the help file for
more information.
Figure 3.4—FT Matrix Calculations
ST G0
ST G1
ST G2
ST G3
ST G4
ST G5
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

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bias0
bias1
bias2
bias3
bias4
bias5
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bST G0
bST G1
bST G2
bST G3
bST G4
bST G5
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FxG0
FyG0
FzG0
Tx G0
Ty G0
TzG0
FxG1
FyG1
FzG1
Tx G1
TzG1
TzG1
FxG2
FyG2
FzG2
Tx G2
Ty G2
TzG2
FxG3
FyG3
FzG3
Tx G3
Ty G3
TzG3
FxG4
FyG4
FzG4
Tx G4
Ty G4
TzG4
FxG5
FyG5
FzG5
Tx G5
Ty G5
TzG5
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Runtime Matrix
Bias Vector for
Offset Correction
Operations marked RED are to be performed
for each measurement sample.
Operations marked BLUE are to be performed
only once at the beginning of a measurement.
Transducer
ATI Amplifier
(if included)
Customer’s
Data Acquisition
System
6 gage output
voltages data
Transducer
Calibration
File
Open Excel sheet on the website at
http://www.ati-ia.com/Products/ft/
software/daq_software.aspx
, called
“DAQ F/T Manual Calculations”
Working
calibration matrix
Determine Offset
Correction Voltage
bias0
bias1
bias2
bias3
bias4
bias5
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Note: Temperature compensation
is usually not required. Only older
models may need software
temperature compensation.
Calibration Matrix
Strain
Gage
Data
Force and
Torque Data
(Fx Fy Fz Tx Ty Tz)
bST G0
bST G1
bST G2
bST G3
bST G4
bST G5
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Load in the FTxxxxx.cal file and copy the working matrix
from the spreadsheet to the blue square area.
3.3.1 Strain Gage Data
Strain gage data represents amplified voltages from the transducers that are converted to digital
data by the Data Acquisition system. Use the demo program to monitor the strain gage data during
installation, this can be use to avoid saturation errors which can damage the transducer.