An ant system with two colonies and its application to Traveling Salesman Problem

An ant system with two colonies is proposed for the combinatorial optimization problems. The proposed method is inspired by the knowledge that there are many colonies of ants in the natural world and organized with two colonies of ants. At first, ants perform solution search procedure by cooperating with each others in the same colony until no better solution is found after a certain time period. Then, communication between the two colonies is performed to build new pheromone distributions for each colony, and ants start their search procedure again in each separate colony, based on the new pheromone distribution. The proposed algorithm is tested by simulating the Traveling Salesman Problem (TSP). Simulation results show that the proposed method performs better than the traditional ACO.