Design of active biped walker based on passive dynamic walking model with torso

Abstract

We investigated an active biped walker based on a passive dynamic walking model with a torso which can walk down a shallow slope without any actuation. The active biped walker was composed of a torso, hips, and two legs, without ankles and knees. The motion of the walker was constrained to the sagittal plane. The passive walking model used bisecting hip mechanism in order to hold the torso. We used the passive walking model with the torso to determine the physical parameter values of the active biped walker. The physical parameters, leg center of gravity and leg moment of inertia, were determined so that the walking speed in the passive walking model was maximized. The simulations demonstrated that the walking speed of the active biped walker increased, and the energy efficiency of walking was improved. Thus, we confirmed that the design based on the passive walking model with the torso enabled the active biped walker to improve the walking performance.