Tuesday, August 30, 2011

The Eyes Have It: Machine Vision and the Art of Pick & Place

A recent article written by FANUC Robotics about delta-style robots points out, “In an ideal world, parts line up and fit perfectly; however, in the real world work pieces often require a wiggle or visual adjustment.”[i] In pick-and-place applications, this is especially challenging. Hard automation requires relatively precise positioning in order for the system correctly pick and place objects. An offset of even a few millimeters can potentially cause a missed pick or a botched place. In high speed packaging machinery, this will cause a system stop. One solution to avoid this down time requires a pair of eyes and deft handling to quickly and correctly pick and place. Enter the vision-capable delta style robot. The combination a FANUC M-1iA delta-style vision-enabled 6-axis robot with a flexible conveyor system creates a highly reliable and fast pick-and-place system that requires very little floor space.
In picking applications, machine vision systems continuously take a snap shot of the product moving on the conveyor, which is often backlit to increase the machine vision’s accuracy. As the article explains, “When a product is identified by the camera, its location is combined with the current position of the conveyor belt. As the product enters a robot work area the robot is able to accurately move to the product and either pick it or work on it while matching the current conveyor speed.”[ii] This allows even oddly shaped objects to be accurately picked and precisely placed at high speeds. Space-hogging expensive bowl feeders can often be replaced with this type of system. ESS has successfully tested these robotic flexible feeding systems for picking and placing droppers, caps, plugs, wands, filter elements, cosmetic pans, ball bearings and more.
Assembly applications are also taking advantage of vision-enabled robotic systems. A six-axis M-1iA robot offers increased flexibility, allowing parts to be fed from the sides of the work zone, increasing the usable work space.[iii] The use of machine vision and flexible conveyors to handle the assembly components further reduces the floor space required for the system, allowing a wide variety of manual assembly processes to be automated. Manufacturers in a range of industries are beginning to embrace machine vision; in fact, ESS has conceptualized and/or manufactured assembly systems for medical devices, diagnostic test kits, filter assembly, cosmetic compact assembly, cap and wand sub-assemblies, and requests for proposals for these types of systems are on the rise. It’s easy to see how machines with vision offer a clear solution in pick-and-place processes.

[i] Bruce, David. “How to Automate More Assembly Applications—The Delta Robot Advantage.” Assembly Magazine 18 May 2011. 18 August 2011. <http://www.assemblymag.com/Articles/Howto/BNP_GUID_9-5-2006_A_10000000000001050346>
[ii] Ibid.
[iii] FANUC Robotics America, Inc. M-1iA Genkotsu (fist) Robot. Rochester Hills, MI: FANUC Robotics America, Inc., 07/2009. Print.