Collision-Induced "Priority Rule" Governs Efficiency of Pheromone-Communicating Swarm Robots

The recruiting system in foraging ant colonies is a typical example of swarm intelligence. The system is underpinned by the use of volatile pheromones which form a trail connecting from nest to food. We have incorporated this property into the behavior of the swarm of real robots. Because the trail is narrow, avoiding overcrowding on the trail, as well as in the environment, is a critical issue in maintaining efficiency of the swarm behavior. In this paper, we studied how “priority rule,” a behavioral rule under which a robot is given priority over the other robot in collision, affect the group-foraging performance of pheromonemediated swarm robots. Using real robot experiments, we found that the alteration in the priority rules can have substantial effects on the group-foraging performance. Our results highlight the importance of implementing “fine-tuning”algorithms to improve the performance of complex swarm systems.