3D Quasi-passive Walking of Biped Robot with Flat Feet - Gait Comparison between Passive Walking and Quasi-passive Walking -

Currently, many bipedal robots have been proposed to realize the high energy efficiency walking. The control input isn’t required for the passive dynamic walking. Generally, a foot of passive dynamic walking robot is an arc foot. In this paper, it is intended to establish a control method and control mechanism to achieve the energy efficient and the stable gait. Therefore, we developed 3D quasi-passive walker with flat feet driven by an antagonistic pneumatic artificial muscle. An antagonistic mechanism is constituted by a pair of McKibben muscle. And, an antagonistic pneumatic system is used as joint actuators of linkage mechanisms which control the torque, joint stiffness and position simultaneously. This paper shows that the 3D quasi-passive walking in the level ground can realize by the swinging (simple) input of the frontal direction, and the stride of the robot is proportional to lateral-plane input. Finally, the gait of the bipedal robot is analyzed by COP (Center of Pressure) and ROS (Roll-Over Shapes).