Nudging or Waiting?: Automatically Synthesized Robot Strategies for Evacuating Noncompliant Users in an Emergency Situation

Robots have the potential to assist in emergency evacuation tasks, but it is not clear how robots should behave to evacuate people who are not fully compliant, perhaps due to panic or other priorities in an emergency. In this paper, we compare two robot strategies: an actively nudging robot that initiates evacuation and pulls toward the exit and a passively waiting robot that stays around users and waits for instruction. Both strategies were automatically synthesized from a description of the desired behavior. We conduct a within participant study ( = 20) in a simulated environment to compare the evacuation effectiveness between the two robot strategies. Our results indicate an advantage of the nudging robot for effective evacuation when being exposed to the evacuation scenario for the first time. The waiting robot results in lower efficiency, higher mental load, and more physical conflicts. However, participants like the waiting robots equally or slightly more when they repeat the evacuation scenario and are more familiar with the situation. Our qualitative analysis of the participants' feedback suggests several design implications for future emergency evacuation robots.