Ornithoid Gait Generation Based on Parametric Excitation

Abstract

We have applied a parametric excitation method to a kneed biped robot with semicircular feet and have shown that the robot can walk sustainably with only knee torque. A swing-leg of the kneed biped robot has similar mechanism to an acrobot, and many acrobots are controlled in inverse direction like ornithoid walking. These suggest that inverse bending of a knee restores more mechanical energy than forward bending, and hence, the ornithoid walking can be more efficient. In this paper, we first compare the forward bending with the inverse bending for a double pendulum, and show by numerical simulation that the mechanical energy of the inverse bending increases more than that of the forward bending like human walking. We then propose a parametric excitation based ornithoid gait for a kneed biped robot, and show sustainably walking by numerical simulation. Finally, we compare parametric excitation based ornithoid gait with parametric excitation based human gait, and we show that ornithoid gait is more efficeint.