A routing table approach for minimum time traffic control of multiple AGV systems

A two-staged scheme, in which the path determination stage is divided from the overall motion planning process and performed offline, has been widely adopted for the motion planning of mobile robots. However, relatively little attention has been given to the application of the two-staged scheme to multiple automated guided vehicle systems (MAGVS). In this paper, a systematic two-staged scheme is presented to obtain collision-free minimum-time motions of AGVs along loopless paths. The overall structure of the controller is divided into two tandem modules of an offline routing table generator (RTG) and an online traffic controller (OTC). Real-time computation is guaranteed in that time-consuming graph searching process is executed offline, and OTC looks for the minimum time motion among the k candidate paths. The traffic control scheme proposed is suitable for practical application in centralized MAGVS with zone blocking technique