Can drones find missing items? Every year, companies lose billions of dollars due to misplaced items and faulty inventory records in their warehouses. Consider that the smallest Walmart warehouse is larger than 17 football fields, making it impossible to keep track of all items in the warehouse.

To overcome this challenge, RFly, a drone-based wireless system that was designed can scan and locate items in warehouses. The system leverages cheap, battery-free RFID (Radio Frequency Identifier) stickers, which are attached to every item in the warehouse similar to barcodes. These RFIDs power up and respond with a unique identifier when commanded by a wireless device called a reader. To scan a warehouse, a drone operator dispatches a small, inexpensive, and safe drone which flies throughout a warehouse, cataloging and localizing all the RFIDs in a warehouse.

The key innovation in designing RFly is a new relay that enables cataloging and locating battery-free RFIDs over a wide area. Specifically, due to their battery-free nature, RFIDs are extremely limited by their communication range. RFly’s relay can seamlessly integrate with an existing RFID infrastructure and extend the coverage area of every reader by 100x. Moreover, RFly’s location-finding algorithm collects wireless responses from every RFID along its flight path, then combines these responses to pinpoint the RFID’s location, achieving an accuracy of around a foot. These capabilities enable RFly to scan for objects over a wide area and pinpoint their location to the actual shelf they are placed on.