The Defense Advanced Research Projects Agency (or DARPA) wants robots that can walk like human beings and do other human activities, such as climbing ladders, using tools, and completing other day-to-day activities. But that requires a bit of stability. Now, one team has taken us a step closer to that dream by creating the SRI DURUS robot. SRI is one of the teams funded by DARPA that is tasked with creating robots that are ultimately 20 times more efficient walkers (as compared to their predecessor)s. Recent work shows that DURUS has almost reached its goal of being 20 times better than ATLAS, another bipedal robot.

The DURUS robot can walk more than a mile in man's shoes. A pair of size 13, Adidas sneakers, to be specific. Engineers at the Georgia Institute of Technology have tackled what they describe as a deceptively difficult challenge: develop a battery-powered robot that mimics the subtle complexity of the human footstep. Aaron Ames, an associate professor of automation and mechatronics, said their feat represents a stride in robotic efficiency and mobility and could allow for robots to function more seamlessly in environments meant for humans. "What drives me a lot is the cool factor, to be honest, but that's my professor hat," Ames said.

"Our robot is able to take much longer, faster steps than its flat-footed counterparts because it's replicating human locomotion," said director Georgia Tech's lab and engineering professor Aaron Ames. He explained that the new behavior makes strides towards the eventual goal of having DURUS walk outdoors. DURUS has springs between its ankles and feet that act like elastic tendons in humans. The springs allow the robot to store mechanical energy from the heel strike to be used when the toe pushes off the ground. As you might expect, this makes the system very efficient with a 1.4 cost of transport, a common measure of robotic locomotion.

In the middle of the DRC Finals last year, SRI's DURUS robot slowly and steadily spent over two and a half hours walking 2 kilometers on a single battery charge. This was a Big Deal: DARPA had recognized from the beginning that the original version of ATLAS was horrendously impractical (at least in terms of locomotion), so they funded two different teams, one from SRI and one from Sandia, to design a humanoid robot that could walk 20x more efficiently. SRI's DURUS came very, very close to this goal, achieving a cost of transport of just 1.5 through an innovative combination of hardware, software, and especially gait control. The guy whose job it is to play with this robot is Professor Aaron Ames, who spent much of the last year moving his Advanced Mechanical Bipedal Experimental Robotics Lab from Texas A&M to Georgia Tech, which is why we haven't heard anything exciting about DURUS since the DRC. It sounds like they just got everything up and running a few months ago, and they're now ready to share an impressive new behavior: DURUS can now walk just like a human, while wearing normal (and stylish) human shoes. You may remember that back at the DRC Finals, we asked Ames what he was hoping to do next with DURUS.