Push Recovery Through Walking Phase Modification for Bipedal Locomotion

Abstract

Push recovery capability is an important aspect that a biped must have to be able to safely maneuver in a real dynamic environment. In this thesis, a generalized push recovery scheme to handle pushes from any direction that may occur at any walking phase is developed. Using the concept of walking phase modification and depending on the severity of the push, a series of intuitive and systematic push recovery decision choices is presented. The result is a biped that could adapt according to the magnitude of disturbance to determine the best course of action. Numerous push recovery experiments at different walking phases and push directions have been tested using a 12 DoF realistic biped model in Webots dynamic simulation. Afterwards, the performance evaluation and insights from our work are presented. Based on the performance analysis during our experiments, an additional controller is introduced to further improve the overall scheme. The versatility and potential of the overall scheme is also shown through a demonstration of the biped balancing on an accelerating and decelerating cart.