Deliberate Delays During Robot-to-Human Handovers Improve Compliance With Gaze Communication

As assistive robots become popular in factories and homes, there is greater need for natural, multi-channel communication during collaborative manipulation tasks. Non-verbal communication such as eye gaze can provide information without overloading more taxing channels like speech. However, certain collaborative tasks may draw attention away from these subtle communication modalities. For instance, robot-to-human handovers are primarily manual tasks, and human attention is therefore drawn to robot hands rather than to robot faces during handovers. In this paper, we show that a simple manipulation of a robot's handover behavior can significantly increase both awareness of the robot's eye gaze and compliance with that gaze. When eye gaze communication occurs during the robot's release of an object, delaying object release until the gaze is finished draws attention back to the robot's head, which increases conscious perception of the robot's communication. Furthermore, the handover delay increases peoples' compliance with the robot's communication over a non-delayed handover, even when compliance results in counterintuitive behavior.