Walking pattern generation method with feedforward and feedback control for humanoid robots

This paper proposes a new walking pattern generation method for humanoid robots. This paper uses the linear inverted pendulum model (LIPM) which is composed of zero moment point (ZMP) and center of mass (CoM). Based on LIPM, the proposed method consists of feedforward control and feedback control for walking pattern generation of humanoid robots. The linear quadratic regulator(LQR) as a feedback controller tracks the desired ZMP according to footprints of humanoid robots and makes poles of LIPM stable. The feedback controller, pole-zero cancelation by series approximation (PZCSA) plays a role of reducing the inherent property of LIPM and approximating the transfer function of the overall system including LIPM and controllers to be unity. The usefulness of the proposed method is verified by simulations such as arbitrary time intervals of support phases, arbitrary desired ZMP position and sudden changed desired ZMP position. And the validity of the proposed method is confirmed by the experiment of a humanoid robot using a joystick.