Gaze-Cues of Humans and Robots on Pedestrian Ways

Delivery robots and personal cargo robots are increasingly sharing space with incidentally co-present persons (InCoPs) on pedestrian ways facing the challenge of socially adequate and safe navigation. Humans are able to effortlessly negotiate this shared space by signalling their skirting intentions via non-verbal gaze cues. In two online-experiments we investigated whether this phenomenon of gaze cuing can be transferred to human–robot interaction. In the first study, participants (n = 92) watched short videos in which either a human, a humanoid robot or a non-humanoid delivery robot moved towards the camera. In each video, the counterpart looked either straight towards the camera or did an eye movement to the right or left. The results showed that when the counterpart gaze cued to their left, also participants skirted more often to the left from their perspective, thereby walking past each other and avoiding collision. Since the participants were recruited in a right-hand driving country we replicated the study in left-hand driving countries (n = 176). Results showed that participants skirted more often to the right when the counterpart gaze cued to the right, and to the left in case of eye movements to the left, expanding our previous result. In both studies, skirting behavior did not differ regarding the type of counterpart. Hence, gaze cues increase the chance to trigger complementary skirting behavior in InCoPs independently of the robot morphology. Equipping robots with eyes can help to indicate moving direction by gaze cues and thereby improve interactions between humans and robots on pedestrian ways.