Passivity-based balance control for a biped robot

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.