MTS WIFT Mini Transducer Interface - Manual (Page 24)

SWIFT ® Mini TI 24
Transducer Interface
Hardware Overview
Transducer Interface
The TI performs cross talk compensation, transforms the loads from a rotating to
a non-rotating coordinate system, and produces an analog output signal suitable
for most data recorders.
Cross talk
compensation
Cross talk occurs when a force is applied to one axis, but a non-real force is
measured on another axis. The SWIFT sensor design has very low inherent cross
talk. The TI compensates for cross talk by subtracting cross talk values measured
during calibration.
Signal conditioning
The TI is specifically designed to be used for both spinning and non-spinning
applications. The TI performs signal conditioning and communications
functions. The output from the TI is a high-level signal suitable for input into a
multichannel data recorder or an MTS Automated Site Controller (ASC).
The TI transforms eight inputs (amplified bridge signals) into three forces and
three moments by the following process:
• Applying a zero offset and scaling the signals
• Using a geometric matrix to transform the signals into three forces and three
moments in the transducer reference frame
• Using a cross-coupling matrix calculation to scale and sum the individual
signals into each output
• Using an offset matrix to shift the coordinate system along the y-axis
• In spinning applications, using a rotational transformation to put the forces
and moments into a stationary reference frame
or
Angular Velocity
signal (+/- 10 V)