Analyses of Humanoid Visual Lifting Biped-walking and Spontaneous Arms’ Swinging by Dynamical Coupling

Biped locomotion created by a controller based on Zero-Moment Point [ZMP] known as reliable control method looks different from human’s walking on the view point that ZMP-based walking does not include falling state. However, the walking control that does not depend on ZMP is vulnerable to turnover. Therefore, keeping the walking of dynamical motion stable is inevitable issue for realization of human-like naturalwalking—we call the humans’ walking that includes toe off states as “natural.” In this paper, walking model including slipping, bumping, surface-contacting and point-contacting of foot is discussed. Then, we propose a ”Visual-Lifting Control” method to enhance standing robustness and prevent the robot from falling down without utilizing ZMP, i.e., whosewalking involve falling down states. Simulation results indicate that this strategy helps stabilize bipedal walking even though ZMP is not kept inside convex hull of supporting area. Moreover, we point out that arms begin to swing spontaneously by dynamical coupling among body links without input torques concerning the arms’ joints.