Ah, spring has sprung. The weather’s warm, the trees are starting to bud, and robots are frolicking about — including ATRIAS, a two-legged bot developed by researchers at Oregon State University.


When we last saw ATRIAS, it was getting pelted in a rather one-sided game of dodgeball. The robot, whose name stands for “assume this robot is a sphere,” is considered the most efficient human-sized bipedal robot owing to its unique bird-like leg-structure and lightweight components. Its developers at OSU say it represents the future of two-legged running robots.


For the latest field test, ATRIAS was taken outdoors to see how it would fare on uneven terrain full of lumps and bumps. The bot was tethered to a safety harness on a supporting frame, but the rig did not aid in walking or supply any energy; it was simply there as a safety mechanism to catch ATRIAS if it fell. The program has been supported by an original $4.7 million, four-year grant from the Pentagon’s advanced research wing, DARPA.

ATRIAS did well during the test, though sensor glitches caused it to slip a couple of times. It moved smoothly and efficiently, maintaining balance even as balls were tossed at it. Uneven terrain did not pose a problem as it walked at just above three miles per hour.

“It already appears that ATRIAS is three times more energy-efficient than any other human-sized bipedal robots,” noted Christian Hubicki, an OSU postdoctoral scholar, in a statement “And this was the first time we’ve been able to show its abilities outside, in a far more challenging environment than anything in a laboratory. This is part of a continuous march toward running robots that are going to be useful and practical in the real world.”

Aside from its lightweight design, ATRIAS has six electric motors that are powered by a lithium polymer battery, which is substantially smaller than power packs typically used on other robots.


Looking ahead, the researchers are hoping to see the technology applied to assistive devices, including prosthetic limbs and exo-skeletons. The military would like to use it for dangerous situations and disaster response.