MTS SWIFT 20 Ultra Sensor - Manual (Page 19)

Construction
SWIFT 20 Sensors Hardware Overview 19
Hub adapter
The hub adapter attaches to the inner diameter of the transducer, allowing you to
place it at the original position of the spindle face of the vehicle. The hub adapter
enables you to maintain the original position of the tire on the vehicle while the
transducer is attached to the vehicle (the tire will not protrude from the vehicle).
Components Set Up for Test Track
Slip ring bracket
The slip ring bracket is used to attach the slip ring to the transducer. It has
internal wiring that provides excitation power to the strain gage bridges and
brings signals out from the transducer to the slip ring.
Encoder
An encoder measures the angular position of the transducer. The SWIFT sensor
uses an optical encoder that counts off “ticks” to measure the angular position as
the wheel rotates. In applications using a slip ring, the integral encoder measures
2048 (512 plus quadrature) points per revolution (ppr) with a resolution of 0.18
degrees and an accuracy of 0.18 degrees.
Slip ring
The slip ring allows you to output the transducer bridge signals and angular
position to the TI. A transducer data cable attaches from the slip ring to the back
panel of the TI. The slip ring is not typically used for non-spinning applications.
Anti-rotate device
The anti-rotate device is attached to the stator portion of the slip ring and the
vehicle’s suspension (or other non-rotating point). It is able to move up and down
with the vehicle. Its primary function is to provide a fixed reference point for the
optical encoder. Its secondary function is to prevent the cable from rotating with
the wheel and becoming tangled or breaking.
The anti-rotate device is mainly used for road data collection. Although it can
also be used for short periods of time on a road simulator. MTS does not
recommend this use. Due to the extreme fatigue loading characteristics of
durability testing on road simulators, we suggest that you either remove the slip
ring assembly before installing the vehicle on a road simulator, or use it only for
iteration passes, then promptly remove it.
Telemetry Model Slip Ring Model
Slip
Ring
Slip Ring
Bracket
Transducer
Interface
Cable Bracket
Anti-rotate Device
(Bend to fit vehicle)
Transducer
Customer-supplied
Attachment Bracket
Wheel Rim
Customer-supplied
Rim Adapter Flange
Attach to
vehicle
suspension
Wheel Rim
Transducer
Anti-rotate
Device
Hub
Adapter
Hub
Adapter
Brake Rotor
Telemetry Bearing
with Hub Electronics
Transducer
Interface
Cable
S20-49