DYNAMIC ROUTING STRATEGIES FOR AUTOMATED CONTAINER TERMINALS

Automated Guided Vehicles (AGVs) play a central role in automated container terminals. To achieve a high productivity of the terminal it is necessary to develop efficient routing methods. This paper studies dynamic routing methods for AGV systems. Dynamic AGV routing offers great advantages over the traditional static routing methods. It can add flexibility, reduce congestion and eliminates deadlock. In this research, a shortest path planning using time windows (SPPTW) concept is used to find the possible alternative routes for each AGV. The optimal route is selected based on the shortest travel time. Two alternatives are compared in this paper. In the first method presented, the entire route between origin and destination is determined before the AGV starts driving. On large, complex terminals, thus with a large number of nodes, this approach can lead to unacceptable long calculations. To reduce the computation time of the algorithm, a second method is proposed which adds a decision point in the middle of the entire route. The purpose of this decision point is to present a more dynamic situation, where AGVs are allowed to stop during route execution. The decision point can be configured as a parking location on the terminal, not blocking the other traffic, or as a recharging point in real terminal operation.