Posture control using foot toe and sole for biped walking robot "Ken"

Abstract

No paper has been published on the active use of the foot toe of the biped walking robots, combined with the normal biped walking by soles. In other words, the sole Of supporting leg is usually assumed to be completely contacted to the floor. To maintain this condition, the robot walking has restrictions such as the maximum walking speed limitation. If the toe contact mode to the floor exists partially through the walking cycle, a variety of walking can be realized. In this paper, a new control method for biped robots, in which the contact of the sole to the floor partially becomes a point contact, is proposed. By this method, the ZMP (the zero moment point) is not necessary to be always inside the support sole, therefore the motion of the body has not to be limited to the quiet motion. As a result, the fast walking and abundant motions of biped robots can be realized by the proposed method When the toe contact is achieved after the ZMP moves from the heel to the too, the robot falls forward In the proposed method, the robot tracks desired trajectories while it is falling forward Simulation results show that the COM (the center of mass) and the heel position of the swing-leg can track the desired circle paths, and heel joint angles con be controlled to the desired angles while a biped walking robot follows a forward filling. The proposed method was verified by the experiment with 6 joints+1 toe DOF biped robot "Ken".