Swinging mass for energy-efficient quadrupedal locomotion

Abstract

Quadrupedal animal, such as dogs, typically have soft but heavy abdomens, whose swinging motion significantly contribute to the energy efficiency of their entire locomotion. This study examines the effect of a swinging mass on quadrupedal locomotion by simulating the soft abdomen of its biological counterparts. A quadruped robot is designed with a swinging mass beneath its trunk. Its pitching motion was evaluated by a mechanical model. The experiment results demonstrate that the swinging mass effectively reduces the pitching motion, thereby improving the energy efficiency of the robot. Although the swinging mass does not always guarantee the energy efficiency of locomotion, the spring stiffness that supports the mass can be obtained for energy-efficient locomotion.