The Control System

The control system is an essential part of the automated guided vehicle system, with the main task being to control the AGVs’ traffic flow.

Outline of WMS control system

 

The system manages transport orders, which involves:

  • order queueing
  • assignment of each order to a suitable AGV
  • monitoring of order progress
  • maintaining constantly updated order status

The control system further manages AGV traffic:

  • route selection
  • prevention of blocking
  • resolution of potential deadlocks (traffic jams)

Several transport orders can be given simultaneously to the control system and are placed in the work queue. The work queue is emptied primarily in first-in, first-out (FIFO) order; however, different priority can be given to orders, depending on, for instance, the load station or the production situation. The WMS can reschedule specific orders and also reassign the drop-off location of a current or scheduled transport task.

The control system keeps the free AGVs waiting for a transport assignment from their home positions situated in strategic locations in the facility's layout. These AGV home positions can be anywhere in the layout but should be close to the main source stations of material flow, to minimise delay. Also, the home position is normally used for AGV battery charging.