You don't have to worry about robots rising up against humanity anytime soon -- the bipedal ones, at least. When they aren't constantly falling down, two-legged robots are running down their power supplies due to inefficient gaits and wasted motion. During a recent DARPA competition, teams from Sandia National Labs and SRI International squared off to see whose robot could walk the furthest. SRI's robot, dubbed the "DURUS," won out by walking 2.05 kilometers in just over two and a half hours while using just 350 watts of power. For those of us who aren't electrical engineers, that's a really impressive feat. In fact, the DURUS uses up to 30 times less power than the ATLAS robot employed in the DARPA challenge.
In standardized terms, the DURUS offers a cost of transport -- how the rate of energy efficient in moving from point A to point B -- of 1.5. It's magnitudes higher than a human's cost of transport of .2 or the DARPA cheetah-bot's .5 rating but it's a massive improvement over the ATLAS whose cost of transport is around 20. SRI researchers accomplished this impressive feat by systematically improving every mechanical component's energy efficiency -- from the motors and actuators to the wiring itself. They even improved the robot's gait to make it more fluid like a human's, rather wobbling back and forth like a wind-up Godzilla toy. With some minor tuning, the SRI team hopes to get the DURUS' cost of transport under 1, which could give it a range of up to 10km using its existing 2.2 kWh lithium-polymer battery.