Analyzing the “knack” of human piggyback motion based on simultaneous measurement of tactile and movement data as a basis for humanoid control

To help with care work and rescue operations, it is necessary for humanoid robots to have the ability to transport humans steadily and gently. In this research we consider "piggyback" motions for transporting humans. Most people can perform this motion, allowing us to measure and analyze piggyback motions of human subjects using tactile sensing and whole body movements to design whole body contact control. One interesting result of this investigation is that frictional forces are skillfully controlled by the carrier. In the first experiment, we study a "knack" that allows the carrier to reposition the rider. In the second experiment we verify the effectiveness of the knack in achieving the repositioning result. We also studied the principle of the repositioning motion, and found that it is similar in many ways to a jumping motion. Then we confirmed the validity of our modeling assumptions using a dynamical simulator.