Proxemic Discomfort in Shared Spaces: The Role of Mobile Robot Behavior and Pedestrian State

As mobile robots become more common in shared public spaces, understanding how their movements affect pedestrian comfort has become a key challenge in human–robot interaction. Although prior research has investigated the effects of robot lateral distance and speed, findings have been inconsistent, with little attention paid to how these factors interact with pedestrians’ mobility states (e.g., walking vs. stopping). To address this gap, we conducted a virtual reality experiment where participants experienced 30 scenarios combining five lateral distances, three robot velocities, and two pedestrian states. Discomfort was measured using standardized questionnaires and real-time button presses. Results showed that discomfort increased at closer distances and higher speeds, with these effects amplified when pedestrians were walking. Discomfort was minimized when robots-maintained distances over 120 cm and moved slower than typical walking speed. This study offers new insights into how robot proxemics and pedestrian mobility jointly shape discomfort, informing proximity-aware navigation design.