Collaborative robots lend a helping hand

Joe’s struggling to package a truckload of parts before noon. Mary can’t keep up on the painting line. Jimmy’s in trouble with the boss because he can’t make quota. These are just a few of the challenges faced by workers on the manufacturing floor, problems that, in many cases, can be solved with collaborative robots.

More affectionately known as “cobots,” collaborative robots are opening new possibilities in manufacturing. In this brave new world, cobots and humans work side by side in a common space not segregated by fences or walls. Need to hand deburr a few hundred parts, or insert bushings into thousands of assemblies? Grab a cobot, show it what to do and go back to whatever intelligent task you were doing.

Cobots are perfectly happy getting stuck with the short end of the manufacturing stick and won’t complain about doing the dirty, dull and dangerous tasks we humans grumble about.

Courtesy of Rethink Robotics

Baxter from Rethink Robotics works side-by-side with humans.

But what are cobots, and how are they different from the robotic arms that load material in CNC machine tools and weld car chassis? The complete, mind-numbing details are available in the robotics safety specification ANSI/RIA R15.06-2012, jointly published by the American National Standards Institute and the Robotic Industries Association. Briefly put, the spec describes collaborative operations as ones where the robot monitors its surroundings and slows down or stops in the presence of a human, where force and power are limited in a work space shared by humans and robots, or where the robot is manually guided by a human.

Bob Doyle, director of communications for RIA, pointed out several additional differentiators between cobots and their stronger, faster and more accurate counterparts. The first is safety. Interfere with an assembly line drone as it bolts wheels onto an F-150 and you might be headed to the emergency room. Granted, safety barriers make this an unlikely situation, but unless using sharp or very heavy objects are part of its duties, injury such as this could never happen around a collaborative robot.

Cobots are also much easier to set up and program than their less human-friendly cousins. “Traditional robotic systems may take months of working with an integrator to implement,” Doyle said. “With a collaborative robot, you can often take it out of the box and have it working the way you want within half a day.”

Sweeping Up

Another factor is cost. Where many industrial robots run upwards of $100,000 after they’re tooled up and integrated with a machine tool or assembly line, cobots start at around $20,000 and don’t require a team of skilled technicians to hook them up. One of these is Baxter by Rethink Robotics Inc., Boston.

Courtesy of Yaskawa Motoman

This SDA dual-arm cobot is from Yaskawa Motoman.

Baxter is an example of a new breed of robots, ones that don’t have to be bolted to the floor or situated in a specific place to operate. These mechanical designated hitters utilize force-sensing technology and embedded vision to recognize objects and react in ways not possible with other industrial robots.

Cobots fill a need that the traditional robotics industry has ignored, according to Jim Lawton, chief marketing officer for Rethink. The long-held paradigm of specific types of automation for specific tasks—for example, welding, applying paint or performing a particular assembly operation—has led to a rigid, expensive automation platform. Worse, in places where robots would fall down on the job, production volumes don’t warrant investment in robotics, or the environment is too flexible for a robot’s set way, a human is plopped in to fill the gaps.

Courtesy of Universal Robots USA

Trelleborg Sealing Solutions in Denmark went from having no robots to having 42 UR robots in 2 years. The robots at Trelleborg enable one worker to manage a cell with eight CNC machines in operation.

According to Lawton, this sort of inflexible technology leads to using automation in places where it doesn’t make sense, creating barriers to innovation and continuous improvement. And while robot manufacturers have worked diligently to bring their wares out of the cage, he said this is not enough. “When we talk about collaborative, it means far more than removing the cage. It means robots that can work side by side with people, performing tasks companies have thus far been unable to automate in that environment.”

These include routine chores, such as counting parts or stuffing boxes, and dangerous tasks where a human might be injured or suffer repetitive motion injuries. In either case, Lawton explained, manufacturers need smart, capable robots that can bridge the gap between traditional, high-volume automation and an imperfect-yet-intelligent human labor force.

‘Owning’ the Robot

Baxter’s not alone. Edward Mullen, national sales manager for Universal Robots USA Inc., East Setauket, N.Y., said his UR-5 and UR-10 robot arms are for companies that either can’t afford or don’t want to rely on external integrators for their robotic needs.

“We’ve designed them so production workers can take ownership of the robot,” Mullen said. “They can set it up to do one thing today, but then reallocate the robot to do something completely different tomorrow.”

Like most collaborative robots, Universal’s URbot utilizes force-limiting technology, which enables it to recognize a collision and stop quickly enough to avoid impact. It performs this feat via smart joints which, if robots were humans, would be its wrists, elbows and shoulders.

Courtesy of Yaskawa Motoman

Yaskawa Motoman says its Functional Safety Unit makes Motoman robots safe for collaborative environments where people interact with the robot during production.

Each smart joint contains a servomotor and electronics that allow it to model anticipated payload, trajectory and power requirements, and differentiate between the force required to do its job and that which occurs when running into a human or another unexpected obstruction.