This biped robot uses mechanics instead of a computer brain to stay upright

Bipeds keep getting better. Instead of slow, heavy, and terrain-sensitive humanoids like ASIMO, researchers are building lightweight and agile bird-like robots, such as Cassie. The better the designs are mechanically, the less power and smarts are required to keep the robot upright. This is a virtuous cycle that's an encouraging sign that some of these biped research projects might actually be useful someday.
The Institute for Human and Machine Cognition in Florida just unveiled its Planar Ellip