Abstract
Passive dynamic walking requiring little exertion is one way of realizing efficient bipedal locomotion. In this case, forces should be converted only to shape ideas for the bottom leg, which naturally alternates the vibration of the roll and yaw axes. To achieve our objectives, in this study we focus on a spinning top, and the change in the direction of movement about the rotation axis was defined as irregular motion. It was shown that this method of realizing motion axis conversion occurred during rotation. An initial angular velocity is generated on the center axis of the solid body's curved surface, and changed the motion into a backspin. First, it was confirmed that we can accurately describe a half ellipsoid as a twisted solid curved surface on its center axis. Next we changed the contact point. By adjusting the angular momentum, we also showed the method of momentum vector conversion through friction. We extracted the constraint condition, and a translational direction element of the angular momentum vector was synthesized. Finally, we showed a method for converting the irregular motion into translational motion, so that the irregular motion can realize a twist angle and an ellipsoid shape.
