Abstract
Achieving energy-efficient dynamic walking has become one of the main subjects of research in the area of robotic biped locomotion. It has been clarified that approaches based on passive-dynamic walkers accomplish it. In general, however, passive dynamic walking is realized by only the legs and the effect of an upper body has not been clarified. Based on the observations, this paper deeply investigates what effects an upper body had on the performances and stability of dynamic biped locomotion. We first consider adding an upper body, which is introduced as a simple 1-link torso, by means of a bisecting hip mechanism so as not to destroy natural dynamics of the biped model. In the second, we analyze the robot's driving mechanism and apply underactuated virtual passive dynamic walking as a method for generating efficient dynamic gait. We confirm that highly efficient dynamic walking is realized with a specific resistance of 0.01, and investigate the effects of physical parameters of the upper body through numerical simulations.
