Self-Organising in Multi-agent Coordination and Control Using Stigmergy

Abstract

In order to cope with today’s dynamic environment, the described manufacturing control system is designed as a self-organising multi-agent system. The design of this novel system implements the PROSA reference architecture [1]. Coordination among agents is done indirectly through a pheromone-based dissipative field as is done by social insects in coordinating their behaviour. In this case, our agents act as social insects interpreting the pheromones put by the others in the environment. This control system is built from the basic elements of any manufacturing controller, namely products, resources and orders. However, the overall control system is constructed not only from those basic elements but also employing the appropriate interaction patterns among the agents who represent them. For coordination purposes, the agents send out a kind of mobile agents – artificial ants – to lay down information on the environment. In our case, where fulfilling the manufacturing orders is the main concern, there are at least 3 types of ant in this system: (1) feasibility ants – to propagate information concerning the feasible finishing routes; (2) exploring ants – to explore the feasible routes; and (3) intention ants – to propagate the route preferences. The overall mechanism enables the system to exhibit a self-organising behaviour.