Machine Vision: Easier to Implement, Easier to Use
Software platforms are making vision systems more efficient and user-friendly.
by Erik Swain, Senior Editor
The machine vision system market continues to grow at a rapid pace. For the pharmaceutical packaging sector, that once might have been attributed mainly to regulatory pressures, but now the chief factor cited is technological innovation.
Perhaps the biggest factor is the shift from hardware-based proprietary systems to software-based systems that can be run on a personal computer (PC). This has enabled anyone familiar with a PC and Microsoft Windows to understand how to operate such a system and has helped bring costs down.
Focus Automation Systems' Pharmavision inspects the entire label surface.
"The PC has helped to standardize nonvision functions like user interface and data collection and put them in a standard, more maintainable format," says George Blackwell, president of the Automated Imaging Association (AIA) and product marketing manager for Allen-Bradley (Milwaukee). "If a pharmaceutical packaging machine builder has a standard interface on a machine, it can be used for a machine vision function."
That sort of convenience contributed to another year of double-digit growth in the North American vision system market in 1997, according to a study released in May by the AIA. The pharmaceutical market for general-purpose machine vision grew about 37.5% last year, Blackwell says.
The pharmaceutical and medical device industry is the fourth-largest user of vision systems, accounting for $22.8 million in revenues and 1076 units sold last year, according to the study. The market is expected to grow about 15% per year in pharmaceuticals and 21% per year in medical devices for the next five years.
The regulatory climate has helped spur this growth, and should continue to do so. "Starting about three years ago, regulatory issues became the primary driving force" behind the move toward machine vision, says Grayton Latam, sales manager, Longford Equipment International Ltd. (Toronto). That's when FDA sent out signals it was going to require "100/200" inspection on all pharmaceutical labels, to cut down on recalls resulting from mislabeling. That is, 100% inspection by machine, or 100% manual inspection by two people. Such a requirement would favor machine vision, but the industry is still waiting for the rule to come down.
Increased ease-of-use has been very important in machine vision's proliferation in the pharmaceutical industry, which had not embraced the technology until recently. Power has also improved, according to Nello Zuech, president, Vision Systems International (Yardley, PA).
The software technology "fits the corporate infrastructure. [Most companies] have the support mechanisms in place for the computer technology, but not for hardware-based machine vision platforms," explains Dave DeJean, vice president of product marketing, Systech (Cranbury, NJ). "If you reduce the amount of hardware you have to use, the cost of ownership goes down."
And, he says, such a vision system can be networked with a company's other systems, enabling them not only to reject product but also to log information about each rejection, which can be used for future purposes.
Another advantage of digitization is that it can be more precise, says Michael Valverde, director of communications, DVT Corp. (Norcross, GA). "What if you want to pick out one set of eight, rather than reject an entire footprint," he asks. "That kind of logic setup is not easy on a lot of systems, but on [systems like] ours it is. We can reject the one bad cell and reduce scrap. There is a lot of on-the-fly capability for logic that wasn't there before."
More than 75,000 bottles can be inspected per day by the Allen-Bradley CVIM2.
No matter how powerful the PC or programmable logic controller (PLC) is, a vision system is only as good as its cameras and lighting. So innovations have come in those fields as well.
Eastman Kodak's Motion Analysis Systems Div. (San Diego) has a camera system that doesn't just take pictures of the product, but "is a diagnostic tool for any assembly line, particularly a packaging line," says Wendy Telford, manager of marketing communications. "It's recording continuously. If the machine vision cameras catch a problem, they can send a signal to high-speed cameras to look at this one problem area."
A common software platform also means many installation difficulties are reduced or eliminated. "It's getting easier and easier" to implement vision systems, says Chuck Bourn, director of customer support, PPT Vision Inc. (Eden Prairie, MN). "But it should not be taken lightly. It needs attention by the end-user, especially in the area of training."
You also "must be a good engineer who understands tricks of lighting," says Mac Hashemian, director of operations at Xyntec Inc. (Yardley, PA). "If you can't get a good image, it doesn't matter how good your processing power is."
And, Hashemian says, an end-user must figure out what the future needs of the system will be. "As your manufacturing and inspection needs change, you want to ensure that the core technology is expandable in a modular fashion," he says.
Stand-Alone Machines Still StrongNot every pharmaceutical packager wants, or can afford, a sophisticated network system. There are still those who only need individual machines to serve their vision concerns, so new innovations and developments are occurring there, too.
Global Vision Inc. (Montreal, Quebec, Canada) has developed a web comparator that "allows you to view a web and inspect it at the same time," says Renee Symonds, marketing and sales manager. "A lot of people have web viewing systems, but up to now, you were not able to inspect the web as you were going to press. You can compare electronic images together, which reduces paper and eliminates printer error."
The Unispect system from Steinmetz Machine inspects completely finished products.
Steinmetz Machine Inc. (Stamford, CT) has introduced Unispect, which is "one piece of machinery that goes at the end of the line," explains John Michelotti, vice president. "You take all the bottles and inspect them after you're done. Unless you have total control of the product, you can never be sure you're rejecting the correct one. Labelers don't have control of the bottle, and you don't know where every bottle is." The machine, which includes the Systech vision system, can also be the platform from which to run line control.
Genesis Machinery Products Inc. (Exton, PA) this year debuted a vial-capping system that uses machine vision. The system reads a 2-D code that has been printed onto a component (vial, cap, or seal) of a just-sealed container and then verifies that the code is correct. "With our machine, the sealed vial is still under complete control of the capper," says Gene Fuchs, vice president. "Vials not properly coded are ejected."
APPLICATIONS EXPAND ALONG WITH MARKET
As the popularity of vision systems has broadened in the pharmaceutical industry, so have their applications. "We see it in several areas," says Ron Strauss, president of Focus Automation Systems Inc. (Waterloo, Ontario, Canada). "Pharmaceutical companies want to inspect labels just before they go on the bottle and [also] make sure they have the right label on the right bottle. Suppliers of labels can do a final inspection off-line before shipping, or go to the printing machine and find problems in process, which reduces errors and scrap. Any time you find errors [further] back in the process, it usually pays for itself very quickly." He says Focus Automation's Pharmavision system, which uses a golden template to provide a perfect model for a label and inspect 100% of the label surface, helps in this regard.
Other uses initiated in recent years include inspecting tablets for correct shape, color, and coating; making sure blisters contain complete pills and are sealed properly; and ensuring accurate fill levels. I-300 and Tegra systems from Key Technology Inc. (Walla Walla, WA) can perform those kinds of inspections, says Richard Hebel, the company's vice president, corporate marketing.
In addition, "there has been a convergence of what used to be separate technologies in a vision system," says Noel Coletti, vice president of marketing for RVSI Acuity Imaging (Nashua, NH). "There are 2-D symbologies for label identification. Sometimes vision-based image processing is required. Not only can component parts be inspected using vision, but they can be identified down to the individual lot number. That's relatively new."
VISION FOR THE FUTURE
Most in the industry expect that machine vision systems will continue to evolve, operating at faster speeds at higher resolution, expanding logic capabilities, and coming down in cost. Some also foresee an increase in the use of "smart cameras," which contain embedded application-specific algorithms.
And with more and more companies looking to replace manual visual inspection with automatic inspection, machine vision systems are certain to become an indispensable part of nearly every packaging line.