A multi-pheromone stigmergic distributed robot coordination strategy for fast surveillance task execution in unknown environments

A bio-inspired coordination strategy is improved aiming at reducing the time needed to mobile multiagent systems accomplish surveillance tasks. The original strategy is based on a modified version of the basic ant system algorithm. Only repulsive pheromone are considered in that version. The new strategy version uses other two kinds of pheromone, as well. Now the agents are able to mark strategic locations for reducing the path length. At the beginning the agents try any trajectory to accomplish the surveillance task. After many trials the agents choose preferably the paths that reduce the total length (time) needed to complete the surveillance task. Comparisons between the original and the extended coordination strategies are presented. Results show that the extended strategy achieves the best performance, that is, the surveillance tasks are accomplished in a period of time shorter than that needed by the original one in view of the scenarios examined.