Omnidirectional Push Recovery of Biped Robot based on CoM Velocity

Abstract

This paper proposes a new biped robot push recovery model to make the robot can resist external force while walking. In order to generate the trajectory, the biped robot is simplied as a particle called center of mass (CoM) and a few additional assumptions are used to generate the CoM trajectory.First, the external force is an impulse which means only the velocity of CoM is changed after pushing but the position of the CoM is not changed. Second, the collision of foot and ground is perfect which means there is no energy loss existing during walking. The second assumption is only used in generation of CoM trajectory and other methods are used to compensate for energy loss problem. This balance control strategy does not need large amount of advanced sensor data to estimate robot walking condition but only needs velocity sensor and desired CoM trajectory. At last, simulation was conducted to verify this push recovery method.