MTS SWIFT 40 Sensor - Manual (Page 83)

Test Track Vehicle
SWIFT 40 Sensors Installing the Transducer 83
Choosing a Zero
method
Preferred method—Zero Algorithm 4 is the preferred method for configuring
the calibration file for spinning applications:
ZeroAlgorithm=4
AngleMode=0
This zero method samples all eight input bridges at two positions. After the data
is taken, all eight input channels are analyzed for signal offsets, and bridge zeroes
and angle zeroes are set in the TI.
Alternate methods—Zero Algorithm 1 and 3 are alternate methods for
configuring the calibration file:
ZeroAlgorithm=1
AngleMode=0
Zero Algorithm 1 samples all eight input bridges on every encoder tick, for one
complete revolution. After the data is taken, all eight input channels are analyzed
for signal offsets, and bridge zeroes are set in the TI. The angle offset is then
recorded in a separate step.
ZeroAlgorithm=3
AngleMode=0
Zero Algorithm 3 may be more convenient for some test setups. However, you
must take care when using it, because it is susceptible to two types of errors:
• Noise spikes from power. These can be minimized by following the
grounding suggestions illustrated earlier in this chapter.
• Extraneous loads. Be very careful to rotate the wheel only by touching the
inner hub of the transducer or by engaging the axle (for some vehicles, this
means putting the vehicle in Park) and rotating the opposite wheel.
Because the SWIFT sensor measures loads applied to the outer edge of the
transducer, you should never touch the outer edge while you are spinning
the wheel. The rotation speed should be smooth, in order to avoid applying
inertial braking moments to the transducer.