But despite getting a lot out of using the robot, Evans cannot yet be left alone with PR2. “The first time that he wanted to scratch his nose, we were scared,” admits Cousins. Engineers need to be on hand at all times, he says, because of the robot’s rudimentary awareness and Evans’s vulnerability if something went wrong. “There’s a lot more work to do there to get it to a point where he could do things like scratch or shave on his own,” he says.

Making the robot safe enough to be left alone with Evans will require it to respond to commands more intelligently, and to cope with unexpected problems—such as a person getting in its way.

Some of these refinements are already in development. Willow Garage engineers, and a researcher from Rensselaer Polytechnic Institute, recently developed software that enables the robot to figure out for itself how to best grasp an object (see video).
                                     
Despite the challenges, Willow Garage’s state-of-the-art hardware shows the potential of robots as helpers for disabled people, says Rajiv Dubey, a professor in the Rehabilitation Robotics group at the University of South Florida. His research group is working on a robotic arm that attaches to a wheelchair and has experimented with allowing completely paralyzed people to operate robots using brain-computer interfaces.

Fortunately, robots don’t need to have human-level intelligence to help people like Evans. “You don’t need everything to be autonomous,” says Dubey. “You have a human in the loop, and you can combine that person’s cognitive abilities with the robot’s computational ones.”

In the future, this could mean that the person in charge of a robot will help it by indicating exactly where it should stand, or how to grip something. Other times, the robot will help—for instance, by preventing liquid from being spilled when the person takes direct control of the robot’s arm in order to sip from a cup.