Patent ID: 7400939

Claim:
A robot apparatus comprising: movable means; center-of-gravity horizontal position trajectory determining means for solving a motion equation with a boundary condition regarding a center-of-gravity horizontal position trajectory of the robot apparatus so that the moment around a horizontal axis at a point within a support polygon defined by a plurality of portions of the movable means contacting a floor is zero or approximately equal to zero, and so that at least the position and speed of the center of gravity of the robot apparatus in a next control period are connected to the position and speed of the center of gravity of the robot apparatus in a current control period when the movable means is in contact with the floor; center-of-gravity vertical position trajectory determining means for solving a motion equation with a boundary condition regarding a center-of-gravity vertical position trajectory of the robot apparatus so that vertical translational force acting upon the robot apparatus other than gravity is equal to or approximately equal to zero, and so that the vertical position and speed of the center of gravity of the robot apparatus in the next control period are connected to the vertical position and speed of the center of gravity of the robot apparatus in the current control period when the movable means is not in contact with the floor; and motion state determining means for determining a motion state of the robot apparatus in the next control period so that the moment around the center of gravity of the robot apparatus is equal to or approximately equal to zero, and so that the position of the center of gravity determined by the center-of-gravity horizontal position trajectory determining means and the center-of-gravity vertical position trajectory determining means is satisfied when the movable means is not in contact with the floor.