In a posture control system of a mobile robot, when unexpected external
force acts, it is configured to control to stabilize the posture of the
robot driving the arm link such that, in response to a first external
force that is a component in a predetermined direction of the unexpected
external force, a second external force acts on the arm link in a
direction orthogonal to the predetermined direction. With this, when the
mobile robot is controlled to work that is likely to receive a reaction
force from the object, even if the posture becomes unstable or the robot
receives the unexpected reaction force acting from the object, it becomes
possible to preserve the dynamic balance and to maintain a stable
posture.
