Simulated Responses to Support Surface Disturbances in a Humanoid Biped Model With a Vestibular-Like Apparatus

In this paper, a model of a humanoid biped is developed. The dynamics are formulated to simulate responses to a sudden backwards translational disturbance of the support surface. The effect of joint stiffnesses, the role of vestibular and proprioceptive sensory apparatus in the maintenance of balance, and the involvement of the centers of mass and pressure are taken into consideration and shown in a number of simulations. Toward this end, a three-link sagittal biped with three muscle pairs at the ankle, knee, and hip, and two pairs of two-jointed muscles corresponding to quadriceps-hamstring and the gastrocnemius-antagonist group is subjected to computational experiments. Excursions of the center of gravity and the center of pressure are compared under different conditions. Comparisons to biological results are also discussed.