SOLO: Single-Operator Multi-Robot Platform for Outdoor Field Deployment

Abstract

In applications such as post-disaster search and rescue, unmanned ground vehicles are increasingly deployed in fleets supervised by human operators, who intervene when vehicles deviate from their planned tasks. As fleet size grows, human cognitive capacity limits the number of vehicles a single person can supervise. Autonomy addresses this limitation by reducing how often each vehicle requires operator intervention. However, autonomous multi-agent systems have largely been validated only in simulation, where sensing, actuation, and communication are ideal. These systems degrade under the variability of real-world deployment, and the resulting change in operator intervention is rarely measured. To address this gap, we present an unscripted multi-agent testbed with a web-based operator interface, designed for outdoor field environments. Three robots share a single line-of-sight radio channel with 1200 m range, navigate autonomously using GPS, and close on visually detected objects. A single operator can intervene through three layers: mode override, teleoperation, and waypoint reassignment. We validated the testbed across 12 outdoor field trials totaling 6 hours, verifying that all three robots can operate concurrently at full range under one operator. This testbed provides a basis for future study of how operator attention scales with fleet size.