Evaluation of AGV routing strategies using hierarchical simulation

To analyze the operation of an arbitrary AGV system under selected vehicle routing strategies, we present a simulation model that can handle multiple system layouts, a varying number of AGVs, and a varying number of pedestrians moving around the system. We introduce a dynamic vehicle routing strategy based on hierarchical simulation that operates as follows: at the time of each routing decision for an AGV in the main simulation, subsimulations are spawned for each of a varying number of alternative routes; and the performance observed in these subsimulations is then used to make the routing decision in the main simulation. A case study illustrates the advantages of this strategy