MTS SWIFT 30 Sensor - Manual (Page 85)

Test Track Vehicle
SWIFT 30 Sensors Installing the Transducer 85
Setting up the SWIFT Sensor for Data Collection
To ensure accurate data collection, complete this setup procedure daily before
you begin testing.
The accuracy of the data that you collect depends on the ability of the SWIFT
electronics to “zero out” the forces and angles present in an initial, unloaded
state. During the Zero process, the TI box reads the transducer bridge values and
compensates for any offsets so that the bridge output is 0 at 0.0 V. It also reads
the current angle and compensates for any offset from the Z axis facing up.
You can ensure the success of the Zero procedure by taking these simple
precautions:
Do not introduce extraneous forces or excessive accelerations into the
wheel while rotating it during the Zero process.
Any forces applied to the wheel, tire, rim, spider, or outer portion of the
transducer will cause a Bridge Zero error.
Make sure to apply only a gentle force at a steady rate to the inner hub while
rotating it.
Do not touch or bump the wheel while the transducer is zeroing.
Touching or bumping the wheel will add loads to the transducer, resulting in
an erroneous zero reading.
Avoid all contact with the wheel while the transducer is zeroing. If you suspect that
the zero process is incorrect, begin again
Considerations for
rotating a tire
When using a zero method that collects zero data while the sensor is rotating (i.e.,
algorithm 1 or 3), you must be careful to minimize the forces that are induced in
the transducer’s bridges.
When using one of these zero methods, never rotate the tire directly, or by
grabbing the outer diameter of the transducer. This will introduce forces into the
transducer bridges that will result in a bad zero process and unreliable data.
• Rotate the tire at an even rate to avoid accelerations on the transducer.
• For positive-lock differentials, turn the other tire on the axle to cause the
desired rotation in the transducer you are zeroing.
• If you must touch the transducer to rotate the tire, carefully rotate the tire by
touching only the inner diameter of the transducer.
CAUTION
CAUTION