Article discussing automated visual inspection

1. Testing and Evaluation
Improve Product Quality
for Manufacturers
Whether to protect luxury brands or
human life, automated testing is
essential to ensuring product quality.
By Alex Anderson, Contributing Editor
hen you manufacture aircraft engine parts, product quality is more than
just a competitive differentiator—it can be a matter of life and death.
Having a real-time testing system that automatically measures product Testing is critical
quality parameters and then turns that data into a direct feedback loop According to Mike Lochaas, a marketing
that influences production systems can be a tremendous asset. manager with industrial platform provider
AV&R Vision & Robotics makes industrial automation systems for large original equipment Advantech, Milpitas, Calif., measuring, testing
manufacturer (OEM) jet engine companies, including systems designed to help the OEM cli- and assessing your process is a critical part of
ent ensure substandard parts don’t make it off the shop floor and into the OEM’s engines. One any quality control system. In fact, carrying out
these activities provides an important underly-
of the Montreal, Canada-based company’s breaks each edge, and creates a radius on spe- ing foundation that influences not only the
principle offerings is a part finishing and cific edges as per the drawing specifications. quality and consistency of your products, but
inspection system which uses a six-axis robot The part is displayed to an NI 1722 Smart the efficiency of your production process, your
[from what company?] and smart camera Camera for inspection to look for surface maintenance schedules and your product
system from Austin, Texas-based National defects such as nicks, dents, scratches, and genealogy programs. Every system that needs
Instruments (NI) to examine turbine airfoils tooling marks on the critical surfaces. The production data to function relies on some
following the deburring process. defects are classified according to their shape kind of feedback loop and most of them have
“In the past, operators inspected and using particle analysis tools in the NI Vision some bearing on product quality.
deburred different complex and high-preci- Development Module. After inspection, Jan Pingle, a product manager with Mil-
sion turbine airfoils using deburring tools to properly deburred parts are moved to the next waukee-based Rockwell Automation sug-
finish the parts and then manually inspected production stage while those that fail inspec- gests there are two primary ways to inform a
the airfoils to ensure the parts were within tion are removed. The feedback mechanism is product quality feedback loop with the data it
specified tolerance,” explains Michael Mul- integrated into the workstation and thus has needs to influence operations. You can either
doon, business solutions engineer, AV&R an immediate impact on production. run in-process data collection with automated
Vision & Robotics. “We developed a cell AV&R developed the unit’s human devices, or you have to go out of process and
that can automatically perform these two machine interface (HMI) system with take samples that are then tested in a lab.
processes, ensuring every part leaves the cell NI’s LabView, which allows the operator “The typical in-process approach involves
with the desired quality.” to quickly understand the status of the a standard historian,” says Pingle, adding that
After loading the part into the cell, a robot system, the part under inspection, and the a historian collects data about your manufac-
presents it to a deburring station that removes statistics of each part—including its serial turing process and then makes it accessible
all of the burrs from the root of each airfoil, number—as it is processed. and understandable to plant floor operators so
34 Automation World l July 2011

2. ON THE WEB
Quality Control Read this application
Quality Control was being done visually
story on how a major nutraceutical
manufacturer addressed labeling errors.
by assembly-line workers, which was
Visit http://bit.ly/persp_002 time consuming and inefficient. We
they know what decisions to make to ensure needed to reduce our reject rate to improve our
the smooth running of the operation and the
consistent production of quality goods. “That’s
QC process and reduce this cost.”
the whole idea behind a historian. You mea- provide improved visibility into production specific colored lens for each unique batch.
sure what happens in real time. Then you load operations, improved overall equipment Once the correct color is achieved, plastic
it into an HMI and people can use that to efficiency and—ultimately—improved is molded to create the required shape. The
identify problems and make changes.” quality, it selected FlexNet from Long lenses are then treated with various finishes,
The Milan, Italy-headquartered Luxottica Beach, Calif.-based Apriso Corp. subjected to more than 20 quality control
Group is another case in point supporting “Quality Control (QC) was being done examinations, and packaged for shipment
the broad impact appropriately collected and visually by assembly-line workers, which to an assembly plant.
utilized product quality data can have on was time consuming and inefficient,” says Automating and standardizing critical pro-
the business. Luxottica designs, manufac- Andrea Gallina, plant manager at Luxot- cesses—such determining lens color, shape
tures and distributes fashion, luxury, sport tica’s Lauriano, Italy facility which produces and finish, which is now a fully automated
and performance eyewear. The company’s 70,000 lenses each day and manages more process—has had a tremendous impact on
house and license brands include Ray-Ban, than 350 distinct designs. “We needed to Luxottica’s profitability, says Gallina; in the
Oakley, Bvlgari, Burberry, Chanel, Dolce & reduce our reject rate to improve our QC past, production and waste volumes were esti-
Gabbana, Donna Karan, Polo Ralph Lau- process and reduce this cost.” mated. “Not only do we now have complete
ren and Versace. Unlike AV&R’s aerospace visibility and control over every stage of pro-
clients, lives are not at stake if a sub-par Getting it right duction, but we can also see details about our
product escapes from the production line, A pair of Oakleys, which can cost as much operations for any given phase or time frame,”
but the damage such an event could have on as $400, can be highly customized, with he says. “We can monitor, trend and ana-
a company that differentiates itself with the plastic lenses offered in a dozen colors. Get- lyze specific areas or machines for continuous
highest quality eyewear on the market (and ting the difference between “Iridium Ice” improvement and best-practice enforcement.”
pricing to match) would be significant. and “Persimmon” right starts when the raw Key performance indicators (KPIs) such
When Luxottica went looking for a new materials are mixed with a precise combina- as waste are monitored and reported by
manufacturing control system that would tion of pigmented ingredients to produce a machine and operator, identifying trouble
July 2011 l Automation World 35

3. spots on the line that can be addressed before Murray Goulburn’s facility near the village a solution that would help us maintain con-
they become significant issues. “Our pro- of Koroit uses four dryers to process skim milk sistent quality while increasing final product
duction processes are now done in a more and whole (full cream) milk into a variety of throughput.” Murray Goulburn opted for a
controlled environment, helping to reduce dairy-based powders. Each dryer consists of a solution from Rockwell Automation which
the likelihood of rejecting work in process,” steel chamber standing up to six stories high continually collects data from each dryer
explains Gallina. “QC is still done by the and 20 meters in diameter. The milk—which and utilizes predictive models to calculate
workers, but now those workers have fresh has already gone through an evaporation pro- optimum temperature setpoints for control-
eyes and vastly simplified jobs. Best of all, our cess—is sprayed through the top of the dryer ling and maintaining the desired moisture
QC is now cross-referenced with production as a fine mist. Swirling air, which can reach level during production.
and scrap reports, ensuring 100 percent accu- up to 220 degrees C, removes the remain- Specifically, the system uses sensors to pro-
racy of products leaving the plant.” ing moisture leaving a small particle of milk vide in-line, inferential quality measurements
The impact of embracing this type of QC powder about the size of a dust particle. As the and facilitates real-time and frequent control
program has been felt beyond the wall of the droplets fall, the air cools to about 65 degrees feedback. Several factors that affect drying
Lauriano facility. With the increased reli- C. The powder accumulates on a static fluid efficiency are tracked and managed, includ-
ability of product quality coming in the door, bed and then exits onto a series of vibrat- ing variations in the milk solids concentrate
assembly plants have been able to eliminate ing fluid beds. Powder from the fluid beds is as well as incoming air and humidity. Rather
their own QC inspections and reduce over- sifted in a funnel-shaped hopper from which than requiring an operator to manually check
all time to market. “(Today), we can clearly it is conveyed to the packaging area. Approxi- the drying process every few minutes, the sys-
Those extra tonnes of powdered milk out the door made the
investment in the solution well worth it. Our reduction in energy
costs has also contributed to the ROI by five to 10 percent.”
see and manage our production and quality mately 13 kilograms of whole milk powder or tem automatically collects data inputs every
processes in real-time, which have resulted in 9 kilograms of skim milk powder can be made 15 seconds, resulting in a significant reduc-
improved productivity and greater manufac- from 100 liters of whole milk. tion of moisture content variation. Once
turing excellence. We estimate our produc- According to Geoff Rome, an auto- every hour, a physical sample of the powder is
tion volume has doubled with higher quality mation and utilities engineer for Murray analysed with an infrared spectrophotometer
and less waste,” Gallina boasted. Goulburn, one of the crucial variables that to confirm the model. The results are sent to
Quality issues in the food industry which affects the quality of the powder is its the modeling system where adjustments are
affects consumer health are different from, yet moisture content. Depending on its end automatically made if necessary.
quite similar to, the world of sport and fashion, use, the powder should contain between
although perhaps not quite as dramatically as approximately 3 to 6 percent moisture. The Impact beyond goals
you would see with a defective aircraft engine. key to achieving the right moisture level Like Muldoon and Gallina, Rome credits his
is to control the temperatures of the air new system with making a impact that goes
Watching milk dry entering the tower, the static fluid bed, and beyond the product quality issues initially
The Murray Goulburn Co-operative is the vibrating fluid beds. targeted. Lower moisture variability means
Australia’s largest milk processor and one of In the past, Murray Goulburn operators the average moisture target can be increased
the country’s largest exporters of processed took hourly moisture samples and manu- without compromising product quality. This
foods, turning 35 percent of the nation’s ally changed the temperature setpoints to translates to higher yields produced from the
milk supply into products. control throughput and moisture content. same milk solids, increased dryer capacity
Powdered milk is a core ingredient in a However, the hourly interval was too long, and reduced energy usage.
wide variety of staple foods—from chocolate especially given the importance of the mois- The new system made it possible to reduce
to bread to baby food—but there is more ture balance in the powder. Tests showed moisture variability levels in each dryer by an
to powdered milk production than merely the moisture would often vary by as much average of 52 percent—exceeding Murray
letting the liquid content evaporate. The pro- as 0.3 percent, which not only had a nega- Goulburn’s 35 percent goal and resulting in
cess has to be precisely managed to maintain tive impact on product quality, but caused the production of an extra tonne of powdered
product quality parameters such as color, fla- equipment problems such as blocked dryers. milk product per day across its four dryers.
vor, solubility and nutrition. In 2009 Murray When these would shut down, the result “Those extra tonnes of powdered milk out the
Goulburn installed a system to automatically was wasted resources and reduced yields. door made the investment in the solution well
monitor and control the most critical and “We knew we needed an automated sys- worth it,” Rome said. “Our reduction in energy
delicate part in the manufacture of powdered tem to reduce the moisture variability of the costs has also contributed to the ROI [return
milk—the final drying stage. powder,” said Rome. “Our goal was to find on investment] of five to 10 percent.”
36 Automation World l July 2011