Until just recently, warehouse operations at the Kappa Smith Stone and Knight (SSK) paper warehouse in Birmingham, UK were completely manual. The facility has the capacity to store 5,000 rolls with a combined roll weight of 11,000 tons. Once the rolls, which weigh up to 8,000 pounds each, arrived in the warehouse, all movement was by lift truck.

SSK wanted to automate its warehouse operations to improve safety, reduce operating costs, increase throughput and improve inventory accuracy. The company installed an automatic guided vehicle (AGV) system that consists of six vehicles, bar code identification, optical sensors, and a warehouse management system. The AGVs feature a special clamp device designed to securely grip paper rolls and rotate them 90 degrees.

Immediately, SSK realized an increase in throughput. Together, the six AGVs process up to 36 rolls per hour. Typically only 24 rolls per hour were processed before automation of the warehouse. The vehicles replace twelve manual operators, reducing labor costs.

Just as important, the AGVs improve safety because they operate in a controlled and predictable manner. They travel at a safe speed of 200 feet per minute and are programmed to slow when sensing a person or obstruction on its guidepath. If the obstruction is not moved, the vehicle stops automatically. Further enhancing employee safety, operating AGVs use audible signals and flashing lights to warn personnel of an oncoming vehicle.

The backbone of the system is a computer control program that controls and monitors vehicle movement.

It facilitates vehicle communication, traffic management/path routing, move command generation, graphical user interfaces and links to other plant controls systems.

The controller is interfaced with the warehouse management system (WMS) and uploads movement files to inform the WMS where and when all loads are moved throughout the warehouse. Bar code scanning of individual rolls by the AGV at each pick and drop guarantees the integrity of roll identity through the load movement process, from the warehouse entrance to the storage locations and out to the shipping/staging area. This eliminates the need for time-consuming manual inventory counts that were previously conducted to correct for damaged rolls, mislabeled items, and other mistakes.

The hardware and software that define and control navigation allow the vehicles to be very flexible in response to changes in the system. Laser navigation was chosen for this application because of flexibility and also because it would not interrupt current shipping processes. The system is expected to provide a positive return on investment before SSK's two-year requirement.