Simulating the operational control of free ranging AGVs

Most transport systems using automated guided vehicles (AGVs) are centrally controlled and use fixed, pre-defined routes. Incidents cannot be handled as part of the common routine. Instead of using fixed path layouts, new trajectory planners for AGVs are developed that utilize the complete available space. To accommodate the increased flexibility, new operational controllers must be able to adapt to small deviations and incidents. In this paper an operational controller is presented that aims to satisfy two conflicting goals. First, the controller directs an AGV along a preplanned trajectory with high accuracy. Second, the controller will avoid conflicts with static and dynamic obstacles. These conflicts are caused by small deviations between planned and realized paths, as well as by incidents like equipment failure. A simulation model is built to study the performance of this controller. The quality is compared to a PI-controller without collision avoidance characteristics.