Robot takes power walking to a new level

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: developing 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. "There's a lot of really important applications."

Researchers have long been fixated on the idea of humanoid robots - those that imitate the appearance, movement, speech and even thought processes of human beings. They are the subject of countless sci-fi films (often to cataclysmic end) and, in the real world, many consider them to be the holy grail of modern robotics.

Oddly, research suggests bipedalism is a rather ineffective means of locomotion. Robots that stand upright and walk on two legs generally have less stable footing than their wheeled or multi-legged counterparts - much the way you're more likely to trip and fall while walking than your dog. And robots should ultimately be more perfect than their human creators, right?

That's true, Ames said, but robots also have to exist in a world designed by and built for humans. If robots are to be sent into a burning building to rescue us, for example, they have to climb stairs and navigate narrow hallways. That's harder to do on wheels or many legs, Ames said.

A majority of two-legged robots lumber forward on flat feet, a motion that is not only clunky but inefficient. Until last week, DURUS did the same.

The human stride is decidedly more elegant. The hip sways, the knee bends, and the foot lands gently on the ground. More technically, the heel touches down first, and the human rolls forward onto the ball of the foot before pushing off with the toes to repeat the motion again.

Such grace is very difficult to replicate technologically, Ames said.

"In terms of equations, these things are insane. If you were to write them down, we would have thousands of pages of equations that underline this basic motion of the robot," he said.

The DURUS robot isn't the first to walk like a man. Other universities and companies have achieved that goal, primarily with robots tethered to some sort of external power supply. But the robot developed at Georgia Tech's Advanced Mechanical Bipedal Experimental Robotics Lab, which has been building bipedal robots since 2008, is more efficient than those that came before it. DURUS is also the first to be mounted with battery packs that allow it to walk unplugged for up to 5 hours, meaning it can be transported more easily and deployed in more varied environments.

Of course, DURUS is not without stumbling blocks. The robot cannot stand up when it falls down, for example. Humans, at least for now, still have that functional superiority.

"The ultimate goal is to get robots out in the wild, in disaster scenarios, in space exploration. That will involve robots picking themselves back up," Ames concedes, "but those are simpler problems than this one."