Synergistic 3D limit cycle walking of an anthropomorphic biped robot

Abstract

Human walking emerges from synergy of whole body dynamics: not only legs, but also a torso, arms, and a head are compliantly connected with each other by antagonistic muscles. Although change of activation of a muscle affects whole body motion, such synergy is supposed to play a great role for realizing stable walking. This paper investigates synergistic 3D limit cycle walking of an anthropomorphic biped robot whose joints are driven by artificial pneumatic muscles antagonistically. Since its walking emerges from the synergy, we cannot design the desired trajectory in a top-down manner, but can change an activation pattern of the muscles and figure out appropriate parameters for stable walking. We experimentally demonstrate that the biped walks stably with a simple limit cycle controller. This is the pioneering work for investigating synergistic stable walking of a whole body humanoid.