Balance recovery analysis with constraints of feet-ground for biped robot

Abstract

A biped robot should be able to keep balance under unexpected disturbance, and can take up to four strategies, i.e. ankle, hip, step and reach & grasp strategies to recover balance. In this paper, the relationship between feet-ground constraints, namely the gravity constraints, the friction constraints and the Center of Pressure ( CoP ) constraints, and balance recovery strategy are analyzed. The satisfaction of these constraints imposed bounds on the control torque is investigated. Finally, the friction coefficient and foot length/height ratio affect the joint torques to balance recovery, which can provide theoretical guidance for robot mechanism design.