Easy to Engineer Machine Vision

DVT's Legend 510 Combines Price and Performance


The machine builders and system integrators we recently spoke with make it sound like installing a vision system is becoming a simpler task. Simple and inexpensive, too.

The Legend 510 from vision system developer DVT costs $2,000, not a bad price for those times when your customer demands that you supply an inspection system with your machine.

 A DVT Legend 544 vision system is mounted in the  die to monitor bending of a surgical needle to an accuracy of 0.05°.

Legend Series 500 SmartImage machine vision systems range from the low-cost 510 to the 544c, a $9,995 system that does full-color inspections with 1280 x 1024 resolution. In between, the 542c inspects parts at speeds to 9,000 parts/min., the 544 detects microscopic flaws, and the 530 has an Ethernet connection.

Applications for machine vision cover a wide spectrum. We spoke to five companies that use DVT's vision systems: three are doing parts inspections, one is bending tiny parts, and one is moving an airplane fuselage into position.

"We take measurements from eight cameras to drive a 14-axis servo system to align large sections of an aircraft fuselage," says Roger Richardson, president of Delta Sigma, a system integrator in Acworth, Ga. "Our measurement and positioning accuracy is better than 0.001 in."

At the other size extreme, Dave Duemler, CEO and technical director of Demco Automation, a machine builder in Quakertown, Pa., says he's monitoring the bend of a needle used in eye surgery (photo). "Due to the small size and right-angle mounting of the camera, we were able to install the system right in our bending die," says Duemler. "This gives us real-time feedback of the bend while the part is still being held in the tooling. We are bending the needle to a 0.125° angle with 0.05° accuracy."

DMC, a system integrator in Chicago, installed a system inspecting chewing gum on a packaging line built in Italy. "Each blister in each pack of gum needed to be filled with a properly shaped pellet," explains Leon Grossman, senior controls engineer at DMC. "As each pack passes under the camera, a PLC triggers an inspection and each piece of gum is inspected for presence and appropriate dimensions. Packets are routed according to good, bad, or empty."

"We use a Legend 520 to verify the presence of splines broached into a hub," says Eric Girdham, controls engineer at Michigan Rebuild & Automation, Litchfield, Mich. "The camera not only detects the presence of the splines, but can actually count the teeth. This allows the camera to detect a part that has been double broached."

Matthew Quinn used a DVT camera to replace a competitor's unit that couldn't meet his customer's specs. Quinn is a partner in Epic Vision Solutions, St. Louis, a company that specializes in providing vision systems. "We built a system to do 360° inspection of halogen light bulbs. The application used 140 inspection tools and 50 scripts in three different cameras, all integrated with a Dell PC. Each inspection had to take only 850 msec."

Quinn says the project took nine months to develop, then the vision system couldn't pass the customer's acceptance test because it was too slow. His company reengineered the project using DVT Legend 540 cameras, and completed the project in half the time.

DVT helped. "We had to create a few features not found in the original DVT Frameworks software," says Quinn. "DVT R&D helped, and then instituted the features into their software."

Girdman also likes DVT's support. "Their flexibility, free software, support, and ease of use give them an advantage," he says.

Grossman agrees. He says getting their system running was easy. "The real challenge was integrating the camera system with a PLC program that had comments written in Italian," he notes. "The built-in scripting functions of the Legend allowed the camera to emulate I/O patterns. This eliminated the need for extensive PLC changes."

Richardson and Duemler also agree that vision is easy. "We went to a training course," says Richardson, "and we were making measurements two days after the camera got here."

"Our system was extremely easy to get running," adds Duemler. "DVT's policy of not charging for software and training made the transition from our shop floor to the customer very easy. Our customer was up to speed on the system prior to the machine leaving our facility."

For more information, call 770/814-7920, browse to http://www.dvtsensors.com.

Free Subscriptions

Control Design Digital Edition

Access the entire print issue on-line and be notified each month via e-mail when your new issue is ready for you. Subscribe Today.

controldesign.com E-Newsletters

Biweekly updates delivering feature articles, headlines with direct links to the top news stories that are critical to staying up to date on the industry — company news, product announcements, technical issues and more. Subscribe Today.