Abstract
This paper describes the development of a new sole mechanism for a biped robot to rough terrain locomotion. The developed sole mechanism of the biped robot has the structure of three-toes. The developed sole mechanism can level the bottom of the biped robot by the three-toes on the rough terrain. To stabilize the sole of the biped robot on the level, frictional locking and unlocking mechanisms are used for the developed sole mechanism. The basic effectiveness of the developed sole mechanism is shown in simulation and experiment.