A movable robot includes a main body unit and at least three wheel units.
The wheel units are connected with the main body unit. The wheel units at
least partially project from the main body unit. The wheel units have
contact portions for contact with a floor surface. Rotation drive devices
operate for rotating the wheel units independently of each other. The
main body unit is moved along the floor surface as the wheel units are
rotated by the rotation drive devices. Lines projected onto the floor
surface and originating from axes of rotation of the wheel units are
spaced at substantially equal angular intervals.