ELECTRO-MECHANICAL MODEL AND ITS APPLICATION TO BIPED-ROBOT STABILITY WITH FORCE SENSORS

This paper presents an electro-mechanical model for robot-balancing simulation based on the equivalent-circuit concept for electrical, mechanical, and coupled electro-mechanical domains. Its application to the effect of heel and toe forces at the robot feet on the bipedrobot-standing stability on inclined surfaces is demonstrated. We performed robot simulations to analyze the robot-standing stability on the basis of the interaction between the robot feet and the ground surface. We also performed standing-stability experiments to verify these simulations by embedding force sensors under the robot's feet at heels and toes. The effect of an inclined surface on heel and toe forces as a function of the inclination angle is also studied. The robot stability is maintained by introducing a feet-force feedback in the robot controller in such a way that the ground projection of the centre of mass (COM) is restricted to stay in-between ankle joint and foot edge. Our conducted experiments verify the ability of the proposed force-sensing system for biped-robot stabilization on inclined surfaces, thus confirming that the reported work introduces a practical technique to solve robot stability with heel- and toe-force sensors attached to the robot feet. The developed simulation tool thus enables an improved design and the optimization of the biped robot.