Travel Time Estimation and Deadlock-free Routing of an AGV System

Concurrent operation of multiple automated guided vehicles (AGVs) in a limited space such as a container terminal results in a high probability of occurrences of collisions, deadlocks, and livelocks; all these occurrences decrease the productivity of the AGVs. Therefore, it is important to assign a route to each AGV in a manner that prevents these occurrences. Moreover, the accelerated motion of an AGV makes routing more difficult. In this paper, we propose a method of avoiding collisions, deadlocks, and livelocks using an occupancy area reservation (OAR) table. We also propose a method to estimate the travel time of an AGV with accelerated motion in order to select the most efficient AGV route. The experimental results indicate that our proposed method is effective in increasing the productivity of AGVs when they are operated in a limited space such as a container terminal.