A smooth COG-shifting biped that is omni-directional. Credit goes to Daniele Benedettelli and his book "Creating Cool MINDSTORMS NXT Robots."
About this creation
Each leg is driven by the motor in it's frame to obtain two movements: the ankle can bend, allowing the center of gravity (COG) to shift for steering, and the motor allows the leg to swing back and forth for stepping. The legs are synchronized so the robot walks straight when both motors rotate the same direction, and it turns in place when they rotate opposite each other.