How Should a Robot React Before People's Touch?: Modeling a Pre-Touch Reaction Distance for a Robot's Face

This study addresses the pre touch reaction distance effects in human-robot touch interaction with an android named ERICA that has a feminine, human-like appearance. Past studies on human-robot interaction, which enabled social robots to react to being touched by developing several sensing systems and designing reaction behaviors, focused on after-touch situations, i.e., before-touch situations received less attention. In this study, we conducted a data collection to investigate the minimum comfortable distance to another's touch by observing a data set of human-human touch interactions, modeled its distance relationships, and implemented a model with our robot. We experimentally investigated the effectiveness of the modeled minimum comfortable distance to being touched with participants. Our experiment results showed that they highly evaluated a robot that reacts to being touched based on the modeled minimum comfortable distance.