Jaguar Eyes Quality With In-Sight 1000C
Cognex In-Sight 1000C Vision System
A smile spreads across your
face as you pull your new X400 Jaguar into your driveway.
Your neighbor, peering at you enviously through the window
of his 1986 Chevrolet Cavalier, belies his chagrin with
a quick wave and thumbs up. As you toss your head back in
self-congratulatory jubilation, you notice something peculiar:
The grab handles are misaligned above the windows. What’s
more, the forest-green headliner strikes an ugly contrast
against the crème interior, and the passenger-side
visor is nonexistent.
Fortunately, new Jaguar owners will never have to experience this scenario; Cognex In-Sight 1000C vision systems are used throughout the Johnson Controls Automotive Speke plant in Merseyside, England, to prevent such problems.
The In-Sight 1000C ensures that headliners are assembled
in order, with the correct color, position and orientation
of parts. It’s no easy task; from the time the plant
receives a broadcast call from Jaguar until the finished
headliners roll off the line, there are scores of opportunities
for error. The trick is to assemble the headliners in the
same sequence as the cars they belong to, ensuring that
color schemes, fittings and various optional extras match
the customer’s order perfectly. The finished headliners
are then transported to the Jaguar line to be installed
in the correct car precisely as it arrives at the assembly
point.
Building headliners in sequence poses critical production
challenges, especially for substandard or outdated vision
systems. “The starting point for us was the need to
replace an old line, which relied on mechanically positioned
optical sensors to check the product,” recalls Nick
Bradburn, a manufacturing engineer at JCA. “These
optical sensors required lots of maintenance.” JCA
therefore sought to improve its delivery integrity and enhance
quality while keeping with its continuous improvement policy.
The headliner production process operates on a four-table
assembly line. After the first two tables manually add parts--such
as locator clips, visors, foam blocks and electrical items--to
the headliner, the third table begins its verification duties.
Above tables three and four and connected via Ethernet to
a vision area network, four Cognex In-Sight 1000C vision
sensors look down upon the headliners. The bar code label
on the headliner tells the inspection system which test
parameters to use, passing instructions to a master camera
in each network, which then passes the data to the other
three cameras over the Ethernet.
The vision sensors have a lot to look for in the 90 seconds
allotted to complete a headliner. “We only assemble
two types of headliners, but the task is complicated by
the multiple choices of colors and fittings available to
the customer,” says Bradburn. “When other variants
are included, such as international differences in the garage
door opener and SRX options frequencies, it means that hundreds
of headliner variants are possible.”
Each Cognex In-Sight 1000C camera is a full-featured CCD
camera with on-board processing capability that can undertake
its own set of inspection tasks separately from the central
controller. The 1000C is fitted with additional hardware
to assess the hue, saturation and intensity of its target,
confirming that the correct color parts are fitted. The
vision area network is also connected to a Web server that
transmits captured images to a central storage and archiving
facility.
With hundreds of variant combinations possible on each
headliner, programming the cameras would naturally present
a challenge. The Cognex application circumvents this issue
with a simple spreadsheet approach to configuration. “It’s
just a matter of specifying step-by-step what you want each
system to do,” says Bradburn. “For position
and orientation tests, you mark the area you want using
the relevant on-screen tool before configuring the parameters
needed to identify that shape or its content. The Cognex
approach makes this very easy.” After some experimentation,
Bradburn was able to configure the system to distinguish
colors, flagging erroneous items as mistakes. By continuously
refining the tests, the system becomes increasingly effective
over time.
Because each set of images is captured for analysis and
stored for future use, the production line now boasts 100
percent traceability. “If any quality concerns arise,
we can go back to the captured images of the headliner to
confirm a root cause,” notes Bradburn. “Similarly,
we can use the archive to double-check production issues.”
Cognex In-Sight 1000C Vision System
- Full library of color image processing and analysis
tools
- Rapid reset, progressive scan
- User-friendly spreadsheet configuration platform
www.cognex.com
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