Mechanical impedance characteristics of robots for coexistence with humans

This paper examines the appropriate virtual impedance values of robots coexisting with humans from the view point of human emotions. The values are investigated experimentally using rating scale method which is generally used for evaluating various stimulus subjectively. In the experiments, 11 subjects add force or impact to the robot and evaluate its reaction by the rating scale method. The evaluations are done on 48 combinations of virtual mass, viscous coefficient, stiffness. As the results, the emotions being flexible, pleasant, and human-like are explained by linear regression model of the impedance values and the emotion being reassuring are classified into 4 groups from the view point of contact force and response speed.