A system for estimating a posture angular velocity of a predetermined
part, such as a body 3, of a robot by using motion state amounts of the
robot, including a desired motion of a desired gait, a detected value of
a joint displacement, and a desired value of a joint displacement of a
robot 1 having a gyro sensor (angular velocity sensor) mounted on the
body 3 or the like in a case where no slippage is taking place between
the robot and a floor, e.g., a state wherein the robot is not in a
motion. A drift correction value of the angular velocity sensor is
determined on the basis of a difference between the estimated value of
the posture angular velocity and a detected posture angular velocity
value by the angular velocity sensor, and the detected posture angular
velocity value corrected by the drift correction value is integrated to
determine an estimated value of the posture angle of the predetermined
part.
