Determining color and blinking to support facial expression of a robot for conveying emotional intensity

In the field of HRI, to take advantage of people’s innate ability of communication, researchers have thus far concentrated on facial expression in facilitating human robot communication. However, for the robot to express emotional intensity, other modalities such as gestures, movement, sound, and color are also needed. This paper suggests that the intensity of emotion can be expressed with color and blinking, which are applicable on robots via LED. Although color and emotion have certain relations, it is difficult to implement the findings of previous research in this area due to a lack of quantitative data. In this paper, we determined RGB values of color and blinking period to effectively express intensities of six basic emotions based on quantitative data. Color and blinking are implemented on an avatar and the intensities of emotions are evaluated through surveys with the avatar. It was found that color and blinking helped the avatar express emotional intensity of surprise, happiness, disgust, and anger. For fear, and sadness, the color and blinking did not play a significant role.