Local and random searches for dispatch and conflict-free routing problem of capacitated AGV systems

• The dispatch and conflict-free routing problem for capacitated AGV systems (DCFRPC) is proposed.
• An integer program of the DCFRPC are presented.
• Random and local search methods are proposed.
• The methods are empirically evaluated though computational experiments.

Automated guided vehicles (AGVs) are an unmanned transport system used for the horizontal movement of materials. The dispatching and routing problem (DRP) for AGV systems involves making dispatching and routing decisions. The DRP is an important and fundamental problem in the scheduling of AGV systems, and number of studies have been conducted. However, for the application to real AGV systems, we have to consider additional constraints such as collision avoidance, the capacity of the system components, the ease of changing routes, and robustness against disturbance. This paper studies the dispatch and conflict-free routing problem of capacitated AGV systems (DCFRPC). In the DCFRPC, finite capacity for each vehicle and machine buffer is imposed, and task dispatching and conflict-free routing must be achieved. This paper formulates the DCFRPC as an integer program, and then, local/random search methods are proposed. This paper also empirically evaluates the proposed methods through computational experiments.