Zones formation algorithm in tandem AGV systems:a comparative study

Abstract

In tandem automated guided vehicle (AGV) systems, the shop floor is divided into a group of non-overlapping zones, where each zone is served by a single dedicated AGV. In this paper, a partitioning algorithm for designing tandem AGV systems is proposed. The proposed algorithm serves a number of objectives; minimizing the total handling cost, minimizing the maximum workload in the system and minimizing the number of between-zones trips. The algorithm is equipped with parameters to enable the user to select one of these objectives or a combination of them to optimize. It starts by generating candidate zones with a search technique that takes into consideration the chosen objective. Each candidate zone is then checked for integrity and feasibility to ensure that zones are non-overlapping and can bear their imposed workloads. A 0–1 integer programming model is used to select the zones for the final configuration according to the chosen objective function. The performance of the proposed algorithm is evaluated by comparison with other algorithms from literature in solving a group of benchmark problems. The results of the comparison showed that the proposed algorithm outperformed the other algorithms when considering the shortest time to travel first (STTF) empty vehicle dispatching policy.