Abstract
In this paper, we show that ankle elasticity of biped robots improves energy-efficiency of walking. One of major issues in studies of humanoid robots is the realization of energy-efficient walking. To realize biped robots achieving energy-efficient walking, researchers have studied flat-footed biped robots with mechanical impedance at each ankle from a viewpoint of biomechanics. Although they achieved energy-efficient robotic walking using the ankle elasticity, they have not clearly shown that the effects of the ankle elasticity improve the walking performance yet. To analyze the effects of the ankle elasticity, we first show an equivalence between walking of flat-footed biped robots with ankle impedance and that of arc-footed biped robots using Extended-Roll-Over-Shape (EROS). We then discuss effects of the ankle elasticity from the viewpoint of this equivalence.
