Marked
out for success
The Vehicle Identi cation Number (VIN)
is a car’s unique ngerprint. Usually
applied to the vehicle body after
painting, but before other components have
been installed on the assembly line, the VIN
serves many purposes throughout the life of
a car. Firstly, VINs helps mechanics identify
the right parts and procedures to use in
service and repair activities, and allow
insurers and law enforcement agencies to
identify vehicles that have been stolen, or
illicitly put back on the road after a serious
accident.
The mark, which today is an
internationally agreed standard combination
of 17 numbers and letters, must be
accurate and clear enough to remain legible
PART MARKING & TRACEABILITY ID FOR COMPONENTS
for the life of the vehicle. VIN marks must
also be applied rapidly, typically in cycle
times of just a few seconds. These demands
have encouraged carmakers to nd
automated approaches to vehicle marking.
Production engineers at Jaguar Land
Rover (JLR), for example, recently wondered
if laser marking technology might provide a
better solution to existing scribe marking
processes and subsequently approached
marking and veri cation specialist Pryor
Marking Technology (https://is.gd/tetoxa).
After looking at the requirements, it
quickly became clear to the Pryor team that
conventional laser marking technologies
would not be up to the task. JLR’s
speci cation required marks with a depth of
JLR laser-marked VIN on a
white painted chassis
0.3 mm to ensure the VIN was tamperresistant
and would remain readable
throughout the life of the vehicle. After much
research and experimentation, Pryor
developed a high power laser system that
could be adapted to give a consistent mark
at the right depth, in short cycle times.
The next challenge was integrating the
technology into production, which required
Pryor to apply a host of other smart
technologies. Laser marking is a non-contact
process, so by mounting the marking head
on a robot arm, a system could be created
that would seamlessly adjust to suit the
requirements of different models, with no
need to switch tooling between vehicles, or
build new hardware when future models
were introduced. However, without a physical
connection to the vehicle, ensuring that
marks were applied in exactly the right
place, proved dif cult. A difference in
position of just a few millimetres between
one body and the next could lead to a
misplaced, or unreadable, mark.
To overcome the alignment issue, Pryor
used its expertise in machine vision to
develop a novel solution. A camera,
mounted on the robot next to the marking
head, could be used to locate de ning
features on the vehicle’s body. Combined
with a laser displacement sensor that
measured the distance of the panel from the
marking head, the vision system could be
used to de ne the precise site of the
marking location in 3D space, allowing the
robot arm to adjust the position of the
Steed Webzell examines the
speed, quality and versatility
of the latest laser marking
solutions, as selected by two
notable companies in the car
industry
Gibson Technology is using a
Datalogic Ulyxe laser marking
system on its engine parts
www.machinery.co.uk @MachineryTweets September 2019 77
/tetoxa)
/www.machinery.co.uk