A simple method to estimate the impedance of the human hand for physical human-robot interaction

In this paper, A simple method for estimating the impedance of a human hand is proposed. In a physical human-robot interaction situation, safety is a very important issue because humans are in contact with robots. Since robots become unstable when they contact a stiff external environment or when there is a difference between human motion intention and robot motion, knowing the dynamics of a human hand plays an important role in improving stability and control performance in physical human-robot interaction. The proposed simple method is to drop an object on the human hand and measuring external force and the movement distance of the hand to estimate the impedance parameter. The proposed method can estimate the impedance of the human hand easily and simply than the conventional methods using the robot arm or the dedicated equipment. The validity of the proposed method is verified by comparing simulation results with estimated impedance and actual experimental results.