MTS SWIFT 50 GLP Sensor Heavy Trucks - Manual (Page 22)

SWIFT 50 GLP Sensors 22
Coordinate System
Hardware Overview
Coordinate System
In the transducer, independent strain gage bridges measure forces and moments
about three orthogonal axes. The signals are amplified to reduce the signal-to-
noise ratio. An encoder signal indicates angular position, which is used to
convert raw force and moment data from the rotating transducer to a vehicle-
based coordinate system. The force and moment and encoder information is sent
to the transducer interface (TI).
The TI performs cross talk compensation and converts the rotating force and
moment data to a vehicle coordinate system. The result is six forces and moments
that are measured at the spindle: Fx, Fy, Fz, Mx, My, and Mz. A seventh
(angular) output is available for tire uniformity information, angular position, or
to determine wheel speed (depending on the data acquisition configuration).
The coordinate system shown below was originally loaded into the TI settings by
MTS. It uses the right-hand rule.
Fx
Fy
Fz
Mz
Mx
My
Transducer
Interface
Output signals
±10 Volts
Angular
Position
Bridge
Outputs
S50-010
+Fz
+Mz
+Fx
+Fy
S50-009
Forces Acting on Rim-side of Transducer
Hub Adapter
Mounting Side
Rim Flange
Mounting Side
+Mx
+My