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WAUKESHA, Wis. Now that International Paper
has worked out some of the kinks in the automated inventory tracking system installed in its Texarkana, Texas warehouse, it is offering help with RFID radio frequency identification to others.
At the RFID Conference June 17 near Waukesha, held by eInnovate
and UW E-Business Institute, International Paper analyst Mark Brown spoke about some of the challenges the company faced in taking RFID out of the lab and into a hot, dusty, dirty warehouse.
The basic idea is this: you put tags on products, boxes or whole pallets that will respond to radio signals by transmitting a unique product identification code. Sensors in the right places can track the flow of products through warehouses and stores without anyone manually scanning bar codes.
IP chose to mount the sensors not on the doors, as some do, but on the trucks that transport paper around the warehouse. Each truck identifies the rolls of paper it picks up, and then notifies the main computer of its movements through a separate warehouse-wide wireless network. Drivers can receive immediate notification if they put a roll down in the wrong place and give a reason for doing so for example, the right spot in the loading bay is occupied.
They drive the truck, they put it down, we know where it is, Brown said.
Some of the challenges the warehouse presented were uncontrolled temperatures, an existing wireless network that had to be moved to a different frequency because it interfered with the RFID sensors, and the wear, tear and shock of transport. With paper rolls weighing several tons, studies found that equipment on the back of one of the warehouse trucks could experience shocks 20 times the strength of gravity when the truck so much as drove over a crack in the floor. The truck-mounted sensors quickly evolved from exposed wires and computers that Brown said looked like a science project to small, rugged boxes.
The sensors, too, had to be protected from environmental hazards. Besides the temperatures in the Texas warehouse Brown said the tags were engineered to work in 145 degrees Fahrenheit tags placed on the outsides of the rolls, near the labels, were often destroyed by clamps when the rolls were picked up. The tags are now placed on the insides of the rolls, and the warehouse operators needed to get a license to exceed the normal limits for RF transmission power just so they could read the tags through 72 inches of paper.
The benefits include losing less paper because the system can track rolls that are set down in the wrong locations in real time and alert drivers and supervisors. And with the combination of motion trackers on the trucks and a grid of sensors laid in the concrete floor, the warehouse can track the location of specific rolls of paper to within 4.6 inches, Brown said.
Uses of RFID extend well beyond location tracking, however. A tag connected to a digital thermometer could indicate the temperature of a sensitive product such as food or medical supplies at each point in the supply chain, and packages that have exceeded their safe limits could be detected early. And since a complete RFID network would track the chain of custody who had possession of a package at any given time the proper entity would pay for the loss.
Brown said his teams development efforts have been deliberately vendor-neutral, so that they can work well with existing warehouse installations.
Theres no best tag out there, he said. You have to pick the best tag for each project.
Jason Stitt is a staff writer for the Wisconsin Technology Network and can be reached at email@example.com