Humanoid running based on centroidal dynamics and heuristic foot placement

Abstract

Inspired by the motion of juggling a ball from one hand to the other, humanoid running motion actually can be treated as juggling its center of mass (CoM) from one leg to the other. In both cases, stance phase and flight phase are involved. During the stance phase, the CoM trajectories of humanoid running can be generated based on the juggling motion characteristics. During the flight phase, the CoM follows ballistic dynamics. However, the relative position of feet with respect to CoM can still be controlled for the subsequent landing. The feet positions can be calculated by a simple heuristic foot placement algorithm considering the current CoM state. Afterwards, the CoM and feet tracking tasks are accomplished by a torque controller based on the full dynamics of the robot with respect to kinematic and dynamic constraints. The feasibility of the proposed control method is fully addressed by different simulations.