Visual Lifting Approach for Bipedal Walking with Slippage

Abstract

Biped locomotion generated by control methods based on Zero-Moment Point (ZMP) has been achieved and its efficacy for stable walking, where ZMP-based walking does not include the falling state, has been verified extensively. The walking control that does not depend on ZMP – we call it dynamical walking – can be used in walking that utilizes kicks by toes, which looks natural but is vulnerable to turnover. Therefore, keeping the walking of dynamical motion stable is indispensable to the realization of human-like natural walking – the authors perceive the human walking, which includes toe off states, as natural walking. Our research group has developed a walking model, which includes slipping, impact, surface-contacting and line-contacting of foot. This model was derived from the Newton-Euler (NE) method. The “Visual Lifting Approach” (VLA) strategy inspired from human walking motion utilizing visual perception, was used in order to enhance robust walking and prevent the robot from falling, without utilizing ZMP. The VLA consists of walking gate generation visual lifting feedback and feedforward. In this study, simulation results confirmed that bipedal walking dynamics, which include a slipping state between foot and floor, converge to a stable walking limit cycle.