Abstract
In this paper, we discuss the possibility and properties of passive bipedal walking on a slippery downhill. First, we develop 4-DOF equations of motion and collision for the passive biped robot that contacts with the ground incorporating sliding friction. We reproduce the sliding frictional force acting on the contact point as the Coulomb friction. Second, we show that a stable walking gait can be generated with suitable initial condition and physical parameters through numerical simulations. Furthermore, we discuss the validity of the instantaneous stance-leg exchange through analysis of the collision dynamics.
