Simulation and experimental studies on passive-dynamic walker that consists of two identical crossed frames

This paper proposes a novel spoke-like passive-dynamic walker that consists of two identical crossed frames whose center of mass is positioned on the central axis. The purpose of this study is to develop an easy test-bed for investigating the roles of double-support phase and swing-leg retraction in limit cycle walking. The crossed frame as a swing leg does not have inherent rotational dynamics, and it rotates only in the presence of viscous friction at the central axis. We first analyze the properties of this walker through mathematical modeling. Next, we numerically investigate the gait efficiency, and discuss the effect of inertia moment and mass distribution of the crossed frame. Finally, we briefly report our experimental results.