Bio-inspired walking for humanoid robots using feet with human-like compliance and neuromuscular control

The human foot plays a key role in human walking providing, among others, body support and propulsion, stability of the movement and impact absorption. These fundamental functionalities are accomplished by an extraordinarily rich bio-mechanical design. Nonetheless, humanoid robots follow different approaches to walk, hence, they generally implement rigid feet. In this study, we target the gap existing between the human foot and traditional humanoid-robot feet. More specifically, we evaluate the resulting advantages and draw-backs by implementing on a humanoid robot some of the properties and functionalities embedded in the human foot. To this end, we extract the physical characteristics of a prosthetic foot to develop a human-like foot model. This foot model is systematically tested in simulation in human-like walking tasks on flat ground and on uneven terrain. The movement of the limbs is generated by a muscle-reflex controller based on a simplified model of the human limbs. The gait features and the walking stability are evaluated for the human-like foot and compared with the results produced using rigid feet.