Impact of Path Width and Pedestrian Density on Human-Robot Interaction: A Study in Outdoor and Retail Environments

This paper explores how path width and pedestrian density affect human-robot interaction in outdoor and retail environments. A mobile robot, equipped with a depth camera and 2D LIDAR sensor is operated on pavements of varying path widths and in retail areas with different pedestrian densities in Gera-Lusan, Germany. Unobtrusive field measures ensured the collection of raw interaction data, which was analyzed by grouping it based on path width and comparing it across different environment conditions. The findings highlight the complexity of human-robot proximity and show that path width can not be the only factor defining the spatial relationships in robot-human interaction. Parameters such as pedestrian density, environment of operation (outdoor and retail) and predefined rules for entry and exit in retail spaces affect the spatial relationship dramatically. Unconsidered factors such as age, gender, personal experiences, weather, robot speed, time of day, and weekday vs. weekend effects may further shape interactions. By challenging simplified assumptions, this study emphasizes the need for a more nuanced approach to design robots for real-world environments.