Hybrid supervisory-based architecture for robust control of Bi-directional AGVs

Automated Guided Vehicles (AGVs) are among the most popular automated transportation systems in flexible manufacturing systems (FMSs). Bi-directional AGVs are particularly efficient; nevertheless, their control is complex as they require effective routing procedures to avoid many undesired situations such as head-on con-flicts and deadlocks. This strongly limits their use in production and storage facilities, especially due to the lack of easy-to-implement control procedures. This paper proposes a new zone-control architecture of bi-directional AGVs based on two stages. Any route-computation method can be used in the first stage to minimise some performance criterion. The paper focuses on the second stage where the problem is formalised based on su-pervisory control theory (SCT) in order to secure AGVs paths. This hybrid architecture provides state-space reduction compared to similar SCT-based methods as demonstrated in the simulation study. It also ensures robust deadlocks-prevention in presence of disturbances in case AGVs are scheduled to avoid them.