**5. Conclusions**

This study proposed a novel autonomous role assignment method using the response threshold model through local interactions in swarm robotic systems. In this study, to study the proposed method's robustness in a dynamic environment, we applied the proposed method to ant foraging problems, where the amount and distribution of feeds fluctuate in an environment. The conventional response threshold model, which mimics autonomous role assignment mechanisms of ants, uses the worker ratio in an ant colony as external stimuli. Conversely, the proposed method uses contact stimuli with foraging agents as external stimuli. Our simulations confirmed that, with the proposed method, agents can maintain an appropriate worker ratio and can effectively collect feeds in a dynamic environment compared with the conventional method. In addition, through the analysis of autonomous role assignment processes of ants, we revealed the mechanisms by which agents can specialise as a worker or a non-worker appropriately according to the external environment fluctuations through the frequency of contact stimuli with foraging agents. In future work, we will apply other mechanisms of cooperative behaviours of ants and bees, which are social insects, to swarm robotics systems. In addition, we will create a rescue robot team composed of many autonomous drones.
