Yigal Ringart asked 3 years ago What would the maximum position accuracy of parcels moving on a conveyor at a speed of 1 meter (3.3 feet) per second be, using RFID tags to track each item? Is such an application feasible? If so, what type of tags would be required?
—Yigal
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Yigal,
Typically, a company would install a portal reader at key points along a conveyor and then use passive UHF RFID tags to track parcels moving along the belt. Knowing the location of the specific reader that just read a given tag on a particular parcel would tell you the item's location. If, for some reason, you needed to know the precise location of a parcel moving down a conveyor, you would have to use an active ultra-wideband (UWB) real-time location system.
UWB is a form of active RFID that overcomes multipath issues to locate a tag to within 10 centimeters (3.9 inches), or potentially less with more reader antennas. The issue with using UWB for this application is that the tags are fairly expensive since they utilize a battery to broadcast a signal. If a tag cost, say, $25 and you had millions of parcels to track, then the cost would be prohibitive.
There are overhead passive UHF RFID readers that can determine tags' locations. However, I do not believe such systems would give you accurate location readings for tagged objects moving at a speed of 1 meter per second.
Mark Roberti
Founder and Editor
RFID Journal
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