SET Ltd is engaged in developing a
system to a network rail.
For this project, each ActiWheel
system incorporates an optoNCDT
1420 laser triangulation sensor. “A
critical part of the ActiWheel system
is to understand the lateral position
of the wheel relative to the rail. Then
we can control the wheel and avoid
the ange making contact with the
rail head,” explains Cooney. “We’re
really using the sensors to con rm
that our complex controllers are
actually working correctly.”
The optoNCDT 1420 laser
triangulation sensor with integral
controller is designed for high
precision, high speed, dynamic
displacement, distance and position
measurement applications. The
measuring rate is adjustable up
to 4kHz. A range of different
output signals enable easy
integration of the sensor
into plant or machine
control systems. As well
as analogue voltage and
current outputs, a digital
RS422 interface provides
distance information from
the sensor. All optoNCDT
1420 sensors operate using a
web interface for fast sensor set
up and con guration. Additional
features of the optoNCDT 1420
include video signal display, signal
peak selection and freely adjustable
signal averaging, which enables
optimisation of the measurement
task. A region of interest
(ROI) function allows
background signal noise
to be ltered out.
SET engineers built
of the ActiWheel system
is to understand the
lateral position of the wheel
relative to the rail. Then we
can control the wheel and
avoid the ange making
a special frame that
lies beneath the wheel
axle on the train. The
optoNCDT 1420 sensors
are mounted at a distance
of 400mm from the rail head,
just in front of the ange radius,
pointing directly at the rail head.
Measurement data from the sensors
is output to the ActiWheel control
system via 4-20mA.
“A critical part
contact with the
rail head”
RHOABRUSHST C AONNDD RITEIOLINASBLE IN
“We initially approached Micro-
Epsilon for a suitable sensor
and were very impressed with
the application engineer who
demonstrated the optoNCDT 1420
sensor to us. The sensor met all
our technical requirements in
terms of its exibility, resolution
and robustness. We are measuring
down to 0.1mm accuracy and
lateral movement can be up to
a maximum of 20mm,” states
Cooney.
“The sensors have performed
very well in the demonstrator
project and on other projects where
we’ve tested the ActiWheel system.
They are reliable even in the harsh
environment underneath a train,
where dust, dirt and moisture are
present. They operate reliably
whether it’s a cold, wet, rainy
day or a bright sunny day. In the
demonstrator project, we didn’t
even have to clean the sensors
after a couple of thousand miles of
testing.
“If we need to use the sensors for
other applications, we can calibrate
them ourselves and optimise their
performance accordingly. We’ve
also been impressed by the ltering
function, which lters out noise from
dirt, dust, grease and pieces of bent
metal on the rail head, which means
we can trust the measurement
data.” !
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