A mobile robot has a mobile mechanism, a swing mechanism and a control
unit. The mobile mechanism is of a coaxial two-wheeled type and controls
a forward thrust using inverted pendulum control. The swing mechanism
actively swings an upper body laterally with respect to the mobile
mechanism. A centrifugal force and a gravitational force act on a center
of gravity of the mobile robot. A swing attitude is controlled such that
a location of intersection of an extension of a composite vector of the
forces acting on the center of gravity of the mobile robot and a ground
plane of wheels is kept between left and right wheels.