Control of hoof rolling in an articulated leg

An articulated leg with a hoof is studied in the context of a planar one-legged running machine, the monopod. The monopod runs forward, backward, and in place at relatively low speed. One task for controlling this design is to keep the hoof from rolling. Rolling may be caused by hip torque from the body attitude control and the inertial loading from the acceleration of the monopod during the stance phase. It is shown that coordinating the hip torque with the downward force at the hoof does not control hoof rolling due to excessive pitch disturbance. The method of limiting the inertial loading successfully prevents rolling of the hoof