Dual track and segmented single track bidirectional loop guidepath layout for AGV systems

In this study, we develop integer programming models for simultaneous design of the guidepath track and location of the pickup and dropoff stations for automated guided vehicle systems. Two alternative bidirectional topologies are compared: a dual track loop, and a single track loop partitioned into non-overlapping segments, each served by a single vehicle. We show that the empty vehicle trips have a significant impact on the quality of design in both topologies. More importantly, we identify the difference between empty flow node balancing for a dual track loop with the empty flow edge balancing on a single track loop subject to segmentation. Our work presents an economic decision making model for the trade-off analysis between the costs associated with the additional shop floor space of a dual track loop and the increased vehicle fleet size of a segmented single track loop.