Designing Social Behaviours for Autonomous Mobile Robots: The Role of Movement and Light in Communicating Intent

When autonomous mobile robots (AMRs) share space with humans, establishing trust becomes essential for safe, seamless, and effective interaction. Clear communication of a robot's intent is key to building trust by reducing uncertainty and enabling intuitive interaction. This study explores how AMRs can effectively communicate their intentions through simple, intuitive modalities like movement and light, making their actions more predictable and fostering trust. We designed distinct movement cues combined with light patterns to communicate two key intents; yielding (backing off) and making way (prompting humans to move), tested across four different scenarios. To evaluate the clarity and effectiveness of these behaviours, we conducted an online video study analysing qualitative feedback from open-ended responses. Additionally, we collected quantitative data assessing participants' perceptions of the safety and trustworthiness of the robot. Our findings demonstrate a strong correlation between these perceptions and the robot's ability to display socially aware behaviours.