"I call shotgun!": An evaluation of mixed-initiative control for novice users of a search and rescue robot

The quality of human-robot interaction trails other advances in robotics and may prove to be a limiting factor when deploying remote, mobile robots for critical applications. One reason is that most autonomous robot behaviors are not robust and often degrade in unstructured environments. Another reason is that the design of human-robot interaction (HRI) and interfaces fails to follow basic usability principles or be informed by basic concepts of human-computer interaction. To address both these challenges, we have used a development cycle of iterative usability testing and redesign to hone both our interface and the robot behaviors that support it. The present paper presents results from a wide swathe of over 100 novices who used the resulting system to accomplish a real-world search and detection task. The current interface proved to be highly usable by novices, regardless of age or gender. The study demonstrates the utility of effective robot autonomy and examines the benefits of mixed-initiative control. In particular, the study compares the performance achieved when the robot takes initiative to support human driving versus the case where the human takes initiative to support autonomous robot driving. Results indicate that performance is better when the robot is in the driver's seat. Optimal performance was achieved when the operator focuses on the search and rescue task and provides only intermittent direction to the robot.