Passive-Dynamic Models of Human Gait

Abstract

Human motion is controlled by the neuro-muscular system. But bipedal walking, an example of a basic human motion, might be largely understood as a passive mechanical process [3]. For example, Tad McGeer demonstrated, by both computer simulation and physical model construction (both of which we have repeated), that a somewhat anthropomorphic legged mechanism with four moving links can exhibit stable, human-like walking on a range of shallow slopes with no actuation and no control (energy lost in friction and collisions is recovered from gravity) [1]. So far, our studies focus on two 2D models: a kneed walker, and a simpler `pointfoot' model. These are linkages made of rigid bars that are connected with hinges. Unlike control-based models, where the controller tries to force a motion on the system, the models' gait cycles (exact sequences of repeated steps) are inherent products of the model parameters.