A friction based “twirl” for biped robots

This paper presents preliminary results on generating turning motion of a humanoid robot by slipping the feet on the ground. We start by presenting the fact that such slip motion is used by humans based on actual human motion capture data, and show how this is necessary for sophisticated human-like motion. To generate the slip motion, we predict the amount of slip using the hypothesis that the turning motion is caused by the effect of minimizing the power generated by floor friction. Verification is conducted through both simulation and experiment with the humanoid robot HRP-2. A ldquotwirlrdquo utilizing both feet slip is successfully demonstrated.