Research of human-robot handshakes under variable stiffness conditions

In this study, we made the assumption that the feeling of a firm handshake is related to the stiffness of the elbow joint and we performed handshake experiments under variable stiffness conditions to verify the assumption. EMG signals were recorded to be used as an evaluation. Then human-robot handshake experiments were performed utilizing a handshake manipulator proposed in the previous research. The joint of the manipulator was driven by antagonized artificial muscles, which are considered to be soft actuators designed to mimic the movement of real human muscles. The muscle activations of the subject were compared when the subject shook hand with the experimenter and the manipulator. And it has been demonstrated that even though the subject was not aware of the experiment conditions, the muscle activations are higher in the firm handshake condition in both human-human handshake and humanrobot handshake experiments, which indicated that firmness of handshakes are related to the stiffness of the joint and the EMG signals can used as an evaluation method.