Passivity-based balance control for a biped robot

Abstract

This paper proposes a balance control method for a biped based on passivity. In this method, we design a controller to stabilize the position of the center of mass (COM), the orientation of the upper body and the motion of the swing leg using the kinematic model of a biped. The proposed method is not hindered by complexity of the computation because the proposed controller executes no contact force planning, and uses only a compact feedback for implementation. It is also robust to errors caused by the environment or internal motion. We prove the stability of the system according to the Lyapunov's direct method. Selected simulations are executed to validate the effectiveness and robustness of the proposed controller.