Controller and footprint determining system of a legged mobile robot

With estimating the landing position and orientation of the foot (22) for landing at the landing operation of the robot (1) such as a bipedal mobile robot, the target footprints path of the robot (1). Based two estimated landing position and orientation and the target footprints path, so as to approach the robot actual footprint (1) (foot (column landing position and orientation of the 22)) to the target footprints, future target landing to determine the position and orientation. It determines a desired gait of the robot (1) using at least the determined target landing position and orientation, controls the operation of the robot (1) according to the desired gait. When determining the desired landing position and orientation are taken into consideration legs interference or the like and the robot (1) its mechanical constraints between the constraints existence permissible range of the target ZMP and the like.