Designing Social Cues for Collaborative Robots: The Role of Gaze and Breathing in Human-Robot Collaboration

In this paper, we investigate how collaborative robots, or cobots, typically composed of a robotic arm and a gripper carrying out manipulation tasks alongside human coworkers, can be enhanced with HRI capabilities by applying ideas and principles from character animation. To this end, we modified the appearance and behaviors of a cobot, with minimal impact on its functionality and performance, and studied the extent to which these modifications improved its communication with and perceptions by human collaborators. Specifically, we aimed to improve the Appeal of the robot by manipulating its physical appearance, posture, and gaze, creating an animal-like character with a head-on-neck morphology; to utilize Arcs by generating smooth trajectories for the robot arm; and to increase the lifelikeness of the robot through Secondary Action by adding breathing motions to the robot. In two user studies, we investigated the effects of these cues on collaborator perceptions of the robot. Findings from our first study showed breathing to have a positive effect on most measures of robot perception and reveal nuanced interactions among the other factors. Data from our second study showed that, using gaze cues alone, a robot arm can improve metrics such as likeability and perceived sociability.