**Abstract**

This study proposes a novel autonomous role assignment method for swarm robotic systems using the response threshold model based on local interactions in a dynamic environment. Ants are social insects with high and low pheromone sensitivity. The pheromone sensitivity of ants is related to autonomous role assignment. The response threshold model was proposed to describe the pheromone sensitivity of ants. The conventional response threshold model assumes that an ant knows the number of workers in an ant colony. However, it is difficult for an ant to contact all workers because its functions are very limited. Therefore, our proposed method adopts a response threshold model based on contact stimuli with foraging ants instead of the worker ratio in an ant colony. In this study, to evaluate the proposed method's robustness in dynamic environments, we apply it to ant foraging problems in environments with varying amounts and distributions of feeds.

**Keywords:** swarm robotics, autonomous role assignment, local interaction, ant foraging, response threshold model
