During an automated wheel, tire, and
wheel/tire verification process, a global
manufacturer of automobiles and trucks
was experiencing unacceptably high levels
of false fails. In addition to using a vision
system that could not account for variations
in depth of field or textures on the metal surfaces of the wheel, the system’s wheel training routine rarely worked and the proprietary implementation of the training routine
code meant that operators could not amend
the code.
Rather than employ this proprietary
system, LEONI Vision Solutions Group
determined that by employing a combination dome light and brick light configuration and multiple smart cameras for some
of the inspection nodes, the correct wheels,
tires, and resulting assemblies could be verified. This was accomplished by groups of
Cognex In-Sight 5000-series cameras that
could be trained by system operators, not
just the systems integrator.
Moving targets
Although automotive pro-
duction lines may only
produce one type of car at
a time, fitted wheels and
tires will change depend-
ing on the options package required. Each
car has four standard tires and a spare wheel
and if both types pass down the same con-
veyor, automated machine vision systems
must inspect both, regardless of where each
tire resides on the conveyor. To accomplish
all the required inspections
for the volume of cars pro-
duced across the large expanse
of the production plant, the
automotive OEM required
nine inspection stations in
total. Four of these stations
were used to identify the inner diameter and
tread of the tire to confirm the tire model
number. Since the metal wheels were of dif-
ferent color, depending on the car type for
which they were designed, a further three
inspection stations were used to identify the
color of each wheel.
Due to the distance between the ini-
tial wheel and tire verification stations and
the final assembly verification station –
and the chance that a wheel or tire might
be removed or added between initial and
final verification – it was necessary to per-
James Reed, LEONI
Vision Solutions (Lake
Orion, MI, USA; www.
leonivisionsolutions.com)
On production lines where products may vary in size, shape,
texture and placement, adaptable vision systems are required.
James Reed
Smart cameras target automotive
inspection
