Foot placement method to change velocity of running biped robot

In this paper, a method for a biped robot to run with a velocity change by selecting its foot landing position appropriately is proposed. The zero moment point (ZMP) is used as the criteria to identify the stability of the biped robot. The ZMP is estimated by the position of the center of mass (COM) and the acceleration of the robot. This means that by setting an appropriate ZMP for the robot, the acceleration of the robot can be controlled. In this paper, ZMP is not only used for stability criteria, but also used to change the velocity in running. The ZMP is designed to reach the desired velocity of the robot, and the trajectory to change the running velocity is generated made the assumption that the ZMP is the foot landing position. By using the method, the biped robot can run stably while changing its velocity. The performance of the proposed method was verified by computer simulations.