A legged robot is provided whose trunk link is not prone to wobble in the
front-back direction during walking. The legged robot is equipped with a
trunk link and a pair of legs. Each leg has a pitch joint capable of
rotating the connected links in a plane that intersects with a line
extending in a lateral direction of the robot. Rotation centers of the
pitch joints are located above a center of gravity of the trunk link. The
legged robot walks mainly by swinging the legs backward and forward
around such rotation centers. Hence, the trunk link wobbles mainly in the
front-back direction around the rotation centers as the robot walks.
Because the center of gravity of the trunk link is located below the
rotation centers, the gravitational force acting on the trunk link acts
in a direction to suppress swinging of the trunk link during walking. Due
to this, the trunk link of the legged robot is not prone to wobble in the
front-back direction during walking.