Cobots Learn to Guide People
by Mark Frauenfelder

Robots traditionally have provided extra muscle under the command of a human operator. Now they're helping to guide human muscle. Researchers at Northwestern University in Illinois have announced the invention of the motorless "cobot," a collaborative robot that reverses this human/robot relationship. "Cobots simply can't move on their own at all," says cobot co-inventor J. Edward Colgate. They are designed to work with people, as they perform a task.

Co-inventor Michael Peshkin explains that a cobot/human team could be used to install instrument panels into the cabs of trucks being built on an assembly line. Without guidance, it can be very difficult for a worker to lift the heavy panel and fit it through the opening of the truck door, because there's usually very little clearance between the panel and the door opening. A specially designed cobot could be made, says Peshkin, that provides a "virtual surface," like an invisible funnel, that allows the worker to slide the instrument panel into the truck without banging it against the side of the door. "Workers can maneuver the instrument panel down the middle of the funnel if they wish, but more likely they will prefer to push it up against a virtual surface and just slide it along into the cab."

The virtual surfaces are created by orienting rolling wheels against real surfaces, or by limiting them to a mathematically defined geometry, that matches the shape of the desired surface. The inventors of the cobots are currently using rollerblade wheels. "A few rollerblade wheels can change the direction of motion of a 200-pound skater in a fraction of a second," says Colgate. "That's exactly what a cobot does - it redirects motion by steering."

In addition to industrial applications, the inventors say that cobots will be useful wherever a task can be facilitated by providing a virtual guiding surface, such as in computer-assisted surgery.