Making robots mimic the human hand

Written by New York Times | Updated: Mar 31 2013, 08:14am hrs
The goal of the programme, now in its third phase, is to develop robots and prosthetic devices for wide use

John Markoff

As part of a national research project to develop low-cost artificial hands, the Pentagon has released a video of a robot that can change a tire almost. In the video, the two-armed robot uses a tool to remove a tire from a car. Were almost on the stage where we can put the the nuts back onto the bolts, said Gill Pratt, a program manager at the Pentagons Defense Advanced Research Projects Agency, or Darpa.

The goal of the programme, now in its third phase, is to develop robots and prosthetic devices for wide use. Until now, high cost as well as limits on dexterity and machine vision have been major obstacles to advanced robotic systems. Robotic hands that mimic the capabilities of the human hand have cost $10,000 or more, and computer vision systems have worked only in highly structured environments on a very limited set of objects.

But it is becoming feasible to make hands that will cost less than $3,000 in quantities of 1,000. Two teams from iRobot, a robot maker in Bedford, and the governments Sandia National Laboratories in New Mexico are working on the hand project; they employ a variety of widely available technologies, like cellphone cameras and sensors, to help lower costs. Were definitely watching their progress, said Rodney Brooks, founder of Rethink Robotics, a Boston-based maker of low-cost manufacturing robot systems. The Darpa research has been vital in keeping the United States in the forefront of robotic technology, he said. He likened the current work to Darpa projects in the 1980s and 1990s that led to the robotic navigation technologies crucial to the development of self-driving automobiles.

One of the hands under development comes with three fingers and the other comes with four, and they are able to do a variety of delicate operations. In one Darpa video, a robot hand picks up chopsticks and then a piece of sushi, Pratt said. The various hands are still a work in progress, he noted. The tire-changing video was made when we were using the old hands and not the new hands, and they did not quite have the dexterity to thread the nut onto the bolt in a way that it doesnt cross the thread.

Darpa also set out tasks that it hopes to accomplish during the next phase. One example is to design a robot arm and hand that can search for an improvised explosive device, or IED, by touch. The challenge would be to programme a hand that could open the zipper on a gym bag and then go through the bag and recognise objects by touch. The agency is also financing research groups in two other categories. It has selected the National Robotics Engineering Center at Carnegie Mellon University, NASAs Jet Propulsion Laboratory and the University of Southern California to continue development of high-level software for the next generation of robot arms. Until recently, the agency asked software developers to develop robotic programs for generic individual motions, like moving forward or backward; now it has set out to simply have the robots perform a specific task. You could say things like pick up the bottle, unlock the door, tasks like that, Pratt said. The agency began with six teams and held a bake-off in which it chose three teams to continue in the last phase of the project. In the software project, Darpa supplied each team with a standard hand that it then programmed.

The grasping tasks were done so well that we believe that for the kinds of objects we had them pick up ranging from a ball to a rock to tools like hammers we dont need to do further work in grasping, Pratt said. Manipulating grasped objects was a more challenging task, he said, and one on which the teams would continue to do research. The programme is financed for 18 more months. Darpa is also continuing to finance the development of low-cost arms at Barrett Technologies, a robotics research firm in Cambridge; Sandia; iRobot; and SRI International, a research organisation in Menlo Park, California.

The agency is also planning to create a joint project to transfer some of the low-cost technology advances it has made in the project into a related effort to develop prosthetic limbs for wounded soldiers. Johns Hopkins University has received funds to develop a neural interface a direct link from a robot arm to the human brain and DEKA Research, an independent development laboratory headed by Dean Kamen in Manchester, NH, has developed a separate wearable arm now being considered for approval by the Food and Drug Administration. That robotic arm is close to commercialization, said Geoffrey Liang, acting deputy director of Darpas Defense Sciences Office.