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Setting up the swift sensor for data collection, Setting up the swift sensor for data collection 74 – MTS SWIFT 10 MC Sensor User Manual

Page 74

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SWIFT 10 MC Sensors

74

Road and Track Vehicles

Installing the Transducer

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. The TI box
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 touch or bump the wheel while the transducer is zeroing (after you
have pressed the Zero button).

Touching or bumping the wheel will add loads to the transducer, resulting in
an erroneous zero reading.

After pressing the Zero button, avoid all contact with the wheel until the
transducer zeroing at the current angle is complete. If you suspect that the zero
process is incorrect, begin again.

This zero method samples all active bridges at four 90° intervals (that is, at 0°,
90°, 180°, and 270°). After the data is taken, all mapped input channels are
analyzed for signal offsets, and the X and Z input channels are analyzed to
determine the angular zero point.

The following procedure assumes:

The transducers have been properly installed on the vehicle and the TI boxes
have been connected to the transducers and a power source. See “

Road and

Track Vehicles

” beginning on

page 59

The calibration file for each transducer has been edited, as required, for the
angle mode and polarity, and the calibration files have been downloaded to
the TI boxes. See

“Edit the Calibration File”

on page 53.

Zero the TI

When you zero the TI, you want the vehicle to be level and the transducer to be

as close to plumb as practical. Determine the level position before you raise the

vehicle.

1. Raise the vehicle with a lift or with jacks until each wheel is off the road

surface.

Perform the remainder of this procedure completely for one transducer/TI
box combination at a time.

2. Rotate the tire one full revolution so that the encoder can find the zero index

mark.

CAUTION