Frontal posture control of jumping biped robot using stiffness bias control

This paper introduces a method of posture control for jumping robot on the frontal plane. Human beings can perform the dynamic motion (e.g. running, jumping) by taking an advantage of muscle elasticity. Biped robots with this feature, therefore, have been studied, recently. Especially among them, many robots implemented pneumatic artificial muscles to adopt this feature. These robots have achieved the jumping motion or running motion. Although, a stable dynamic motion has not been achieved yet. Therefore, a control for the stable motion is desired. In the jumping motion, many researches have verified the stabilization on the sagittal plane. Nevertheless, these robots have fallen down after some jumps. One reason is that they cannot deal with the disturbance on the frontal plane. In this paper, a frontal posture control of a jumping biped robot is proposed. This control makes difference between the stiffness of both legs depending on an inclination and an angular velocity of the robot. To verify the effectiveness of the proposed method, we propose a model using this method. Then, this model is examined by a jumping simulation with various disturbances. The results show that this model with the proposed method improves the robustness against the large disturbance.