Factory robots are usually caged off from humans on the assembly line lest the machines’ powerful steel arms deliver an accidental, bone-crunching right hook.
But now, gentler industrial robots, designed to work and play well with others, are coming out from behind their protective fences to work shoulder-to-shoulder with people. It's an advance made possible by sophisticated algorithms and improvements in sensing technologies like computer vision.
The key to these new robots is the ability to respond more flexibly, anticipating and adjusting to what humans want. That is in contrast to earlier generations of robots that often required extensive programming to change the smallest details of their routine, said Henrik Christensen, director of the robotics program at the Georgia Institute of Technology.
''Researchers in labs worldwide are building robots that can predict what you'll do next and be ready to give you the best possible assistance,” he said.
One of those researchers is Julie A. Shah, an assistant professor in the department of aeronautics and astronautics at the Massachusetts Institute of Technology. Ms. Shah once taught robots to do tasks the old way: by hitting a button that essentially told them “good,” ‘'bad,” or “neutral” as they did each part of a job. Now she has added a technique called cross-training, in which robots and humans exchange roles, learning a thing or two from each other in the process.
In a recent study, Ms. Shah and a student had human-robot teams perform a chore borrowed from the assembly line: The humans placed screws and the robots did the drilling. Then the teammates exchanged jobs and the robots observed the humans drill.
''The robot gathers information on how the person does the drilling,” adding that information to its algorithms, Ms. Shah said. “The robot isn't learning one optimal way to drill. Instead it is learning a teammate's preferences, and how to cooperate.”
When the cross-trained teams resumed their original roles, both robots and people did their jobs more efficiently, the study found. The time that the humans were idle while waiting for the robot to finish a task dropped 41 percent, and the time that humans and robots worked simultaneously increased 71 percent, when compared with teams working with robots trained the old way.
''This is a fascinating application of cross-training,” said Andrea Thomaz, an assistant professor of interactive computing at Georgia Tech. “By learning the human's role, the robot can better anticipate actions and be a better partner, even if in the end it will only do one role.”
The humans on the teams also improved their teamwork skills, said Illah R. Nourbakhsh, professor of robotics at Carnegie Mellon University and author of the book Robot Futures, published this month by MIT Press. “In the future, this idea of cross-training will turn out to be really important as robots start to work shoulder-to-shoulder with us,” he said. “We are not very good at adopting the point of view of a robot. This study showed that we can learn, though, with the right signals.”
OBJECTMr. Christensen of Georgia Tech said: “Robots of the future won't just be in manufacturing. Almost any area could have a robot that would help make our life easier,” whether “lifting patients in hospital beds or helping at home.
“But they have to be safe, and they have to have the kind of anticipation that Julie Shah is working on, because they have to be able to automatically figure out what we need help with,” he said.
Gentle, helpful robots aren't just being created in labs; they are also arriving in the marketplace. Since January, Rethink Robotics of Boston has been sending customers its two-armed robot called Baxter, which can work uncaged, moving among people.
''We are shipping robots every day and have a backlog of orders of about three months,” said Rodney Brooks, Rethink's founder, chairman, and chief technology officer.
Baxter, which costs $22,000, can lift objects from a conveyor belt. “You don't have to tell it the exact velocity,” Mr. Brooks said. “It sees objects and grabs them, matching its speed to the speed of the object.”
Baxter is used in manufacturing plants and shops of varying sizes. One example is the Rodon Group, a plastic injection molding company in Hatfield, Pa., where Baxter packs boxes on the factory floor.
Baxter's cameras inspect what is to be lifted, recognizing an object from many angles. In the coming year, Baxter will be able to grab objects not only from above, but also from the side, putting them into a milling machine, for example, and pressing the “go” button. It will also be able to connect with other machines, to synchronize tasks.
''Baxter is a great starting point for this new generation of robots,” said Mr. Christensen of Georgia Tech, who has no connection to Rethink Robotics’ work, “making the technology accessible to companies that before would have had to pay hundreds of thousands of dollars.”
''He's opening up a new market,” Mr. Christensen said of Baxter's work.
Baxter is not the only unfenced robot on the assembly line. A Danish company, Universal Robots, for example, sells a one-armed robot for $33,000 that can also be used without a cage.
Impressive as the new robots are, they soon will have even more advanced skills, said Stefan Schaal, a professor of computer science, neuroscience, and biomedical engineering at the University of Southern California and a director of the Max Planck Institute for Intelligent Systems in Germany. In the future, robots will be able to go onto the Internet and exchange information, leading to vast gains in what they can accomplish.
“It will take time before we get there,” Mr. Schaal said, “but it will happen.”