Abstract
Since most of traditional biped walkers based on Passive Dynamic Walking (PDW) have arc feet and locked ankle joint, they cannot realize multimodal locomotion except walking (e.g. keeping standing posture, running). In this paper, we consider how we can substitute the flat feet with the arc feet. We hypothesize that the arc feet correspond to a circular Roll Over Shape (ROS), which is a shape of trajectory of center of pressure in human walking. We found that this circular ROS was generated by ankle joint driven by flexible muscles antagonistically. Measuring ROS with various tensions of muscles and equilibrium positions of ankle joint, we investigate the relationship between ROS and walking behavior.
