Locomotion

Bipedal Robot

A bipedal robot is a legged robot that walks on two legs, trading the static stability of quadrupeds for a human-compatible form factor and footprint. Control has progressed from zero-moment-point walking in machines like ASIMO, through hybrid-dynamics approaches on platforms such as Cassie, to reinforcement-learned controllers now standard on humanoids from Digit to current commercial platforms. The dynamics are underactuated during single support, making balance a continuous active process.

Why it matters for physical AI

The humanoid industry's central bet is that two-legged, human-shaped robots can inhabit unmodified human spaces, so bipedal robustness on stairs, clutter, and slips directly gates commercial viability.