Self-stable Bounding with a Flexible Torso

Various robotic quadrupeds have been introduced to investigate the realization of dynamically-stable running behaviors. The majority of these platforms involve rigid, nondeformable torsos, a feature that distinguishes them from their counterparts in the animal world, which owe much of their remarkable locomotion abilities to their flexible bodies. Only a few quadrupedal robots employ torso flexibility. An early example is the planar quadruped with articulated torso introduced in the MIT’s Leg Lab, [1]. Contemporary robots with flexible torso include Canid [2] and the MIT Cheetah quadruped [3]. However, only limited information on how torso bending movements affect locomotion is available in the context of these platforms.