Frequently Asked Questions

How do AGVs avoid running into each other while operating on the same path?

AGV traffic separation is generally performed two different ways:

• Central Traffic Controller — This method employs a centralized computer to control the movement of the AGVs in the system. Each AGV communicates with the central controller, which in turn keeps track of the AGV locations. When two AGVs get close to each other along the path or at intersections, the central controller instructs one AGV to wait until the other passes.
• Decentralized Traffic Control — Each AGV performs its own traffic control without the need of a central traffic control computer. As the AGVs catch up with each other along the path or cross each other's path at intersections, they communicate with each other to coordinate their movements. This is via direct AGV to AGV communication.

Systems that do not require a centralized controller have greater redundancy because a central controller failure would otherwise stop all vehicle movement. However, with AGVs that have onboard traffic control intelligence, a failure only affects that AGV — not the whole fleet.

All traffic control schemes are based on maintaining either variable or fixed spacing between vehicles. In the case of fixed spacing methods, the AGVs are separated by specific distances or zones created along the path. Variable spacing methods allow dynamic changes in vehicle spacing to occur. Typically, variable spacing methods bunch vehicles closer together and can result in greater system throughput. Some AGV systems utilize a combination of variable and fixed vehicle separation in the same system.