In recent years, vision-aided robots have been showing up on packaging lines with increasing frequency. As our new century began, relatively few robots were employed in packaging when compared to other industries, with the majority of these found in palletizing/depalletizing. A strenuous and repetitive task involving stationary targets, this application has proved comparatively easy to justify for many packagers, and the number of palletizing applications has increased, at a relatively modest rate, over the course of the decade.

By mid-decade, though, this picture began to change, as robots in increasing numbers started moving up the line and into product pick-and-place operations. This trend has continued despite the recession. Though orders for new robots declined by 30 percent in the first three quarters of 2009, sales to the packaging industry remained relatively healthy (precise figures at this point are hard to come by) with continued growth predicted for 2010.

Why this counter-cyclic movement? The explanation can begin with two words: vision and flexibility. Vision has typically been an essential component of high-speed pick-and-place operations. It has also been expensive and difficult to apply, with the complexities of vision technology multiplied by the complexities of integrating vision systems with robots, given their different coordinate and control systems.

Dick Motley, account manager, North American Distribution, for Fanuc Robotics America Inc., Rochester Hills, Mich., puts a personal and dramatic face on these application engineering difficulties when he recalls, “Prior to coming to Fanuc, I’ve been in meetings on the results of other projects and have seen the vision supplier and the robot supplier literally point fingers at each other.”

That began to change dramatically in late 2006 when Fanuc released its first robotic system with pre-engineered, built-in vision capability. With a plug-in port for the camera on the processor board, and vision software for conveyor tracking, error proofing and other vision functions embedded in the controller, applications could be brought on line faster and cheaper. It was objected in some quarters that these integrated vision systems weren’t suitable for the more complex, high-end applications. Most vision-guided robotic applications in packaging, however, aren’t particularly high-end.

 “Integrating the camera into the robotic controller has proved to be a tremendous advantage for Fanuc and for its customers,” says Steven Prehn, senior product manager of the Material Handling Group at Fanuc Robotics. “Automatically tying the vision into the robotic frame space allowed us to leapfrog the market.”

“After the introduction of that concept,” notes Motley, “our vision sales effectively tripled.”

Meanwhile, competitors were likewise adding to the mix. Adept Technology, Pleasanton, Calif., has been integrating vision with robotics for more than 20 years, and further augmented its line with a release of packaging-specific software. Other robot companies joined in, providing users with additional variety in terms of capability and price, and spurring development efforts within the robot community.

Underlying change

Though the integration of vision with the robotic controller may prove to have been a game changer, the growth of vision-guided or vision-aided robotic applications in packaging stems from more than just this single innovation. Picking an arbitrary but manageable time frame—the last 10 years—it’s clear that both robot and vision companies have been stepping up their games in terms of capabilities, reliability and ease of use.

Compare the specs in robot company literature now with the numbers from a decade ago and you’ll notice that today’s robots are, overall, faster and capable of attaining greater levels of precision and repeatability than their predecessors. The drives tend to be faster and more accurate, and the motors and motion controllers have been improved. Though accurate Mean Time Between Failure information can be difficult to obtain, anecdotal evidence is emphatic on this point: Most of today’s robots are highly reliable, low-maintenance machines.

As for vision, that powerful genie that has often been difficult to extract from its bottle, increases in computing power have allowed the use of more powerful software algorithms to enable the systems to cope with greater degrees of variation in lighting, the Achilles heel of many vision applications in the past. In addition, the development of smaller, cheaper cameras and vision sensors has opened the door for numerous applications that could not be justified in the past.

A focus on these positive changes should not, however, obscure the difficulties that remain. John G. Schwan, spokesman for robotics integrator QComp Technologies Inc., of Greenville, Wis., says that vision systems, despite their many benefits, “are still costly and not compatible in some applications requiring a higher degree of inspection ...