Impedance Characteristics of Robots Considering Human Emotions

Abstract

It is expected that in the future, robots will play important roles in coexisting with humans. Whenever humans come into contact with these robots unexpectedly, the robots must not only be safe for the humans but also be able to adjust their physical softness parameters, which will help humans remain calm and which will be favorable for human emotions. Therefore, it is desirable for robots to control their impedance characteristics in such cases. From these points of view, desirable values of the impedance parameters of robots are investigated in this work by a rating scale method. In the experiment, 11 subjects come into physical contact with an impedance-controlled robot and evaluate this contact subjectively. The evaluations are performed on 48 combinations of virtual mass, viscosity coefficient, and stiffness. In terms of the results, the emotions felt by the subjects with regard to the robots being soft, pleasant, and human-like are explained by a linear regression model of the impedance values, and the emotions of being reassuring are classified into four groups.