Environmental Protection by Robots

Mobile robots are increasingly applied in critical domains such as environmental protection, where precise coordination is essential to avoid collision and ensure effective area coverage. In luminous robot models, coordination is typically achieved through visual cues, as robots lack memory, communication, or global knowledge of group size. The fully-synchronous model provides an opportunity to exploit predictability in robot behavior to develop efficient protection algorithms. Although several approaches address robot movement coordination, few achieve optimality with minimal light usage while ensuring non-overlapping trajectories in unknown-sized teams. This study proposes an algorithm that ensures all robots reach the environment’s boundary without overlapping and without prior knowledge of total robot count (n), using only two lights (black and gold) in a fully-synchronous setting. The algorithm successfully guides robots from arbitrary starting positions to non-overlapping positions along the environment’s circumference in O(n)O(n)O(n) rounds. Robots transition their light from black to gold upon reaching their final destination, providing a visible indicator of task completion. Unlike prior methods that assume robot chirality or require more complex communication or sensing capabilities, this solution is optimal in light usage and functions without coordinate agreement or global information. The results offer a practical and efficient strategy for autonomous swarm deployment in scenarios demanding high coordination with minimal resource use. Future work may adapt this approach to asynchronous modes or non-luminous robot models to broaden its applicability.