To realize a robot that clears requirements of slow motion and structure less prone to break for the robot to enter human living environment and further the ability to avoid an obstruction and to safely stop even if colliding with the obstruction.

Spherical wheel are mounted to the robot to allow slow omnidirectional motion. Even if colliding with an obstruction, it is safe because a wheel body merely turns inside a wheel shell, and a proceeding direction can be easily changed. Some reflecting functions are incorporated to allow joint work with a plurality of wheels operable independently of one another, and one wheel for giving a command is created to allow the efficient operation of the spherical wheel robot.