RFID Reading Drone Tested in Asia Warehouses

SATO and AeroLion have completed a proof-of-concept for an RFID reading drone that captures tag reads at warehouses in Thailand and Singapore, for goods stacked up to 10 meters in height.
Published: January 3, 2020

Drone company AeroLion Technologies has launched a proof-of-concept with automatic-identification solutions firm SATO to provide a passive UHF RFID inventory-tracking solution that can take to the air. The system consists of a high-powered RFID reader and antenna mounted on a compact drone that can fly through a warehouse, capturing inventory counts. The two companies developed the solution with the support of the Yamato Group Research Institute.

Traditional UHF RFID tag reading requires a handheld or vehicle-mounted reader to travel through the aisles of a warehouse, capturing RFID reads from the ground level. That process requires personnel to be on the warehouse floor, which costs a company extra labor hours and increases traffic in the warehouse.

Left: the RFID inventory-tracking drone, jointly designed by AeroLion Technologies and SATO; right: the drone, with an RFID reader, flies along high shelves to read RFID-tagged goods on pallets.

Goods are often stacked high enough that reading their tags can prove challenging for the top shelves. That means some RFID tags may not be captured, and that goods can be missed during inventory counts. In some cases, warehouse workers must climb a ladder to read the highest RFID tags or scan barcodes on the boxes or pallets. “Considering the safety of workers, we decided to utilize drones,” says Kazuhiro Chatani, SATO’s head of logistics business.

AeroLion and SATO have built a potential solution to these problems. They began testing the system with help from the Yamato Group Research Institute, an organization established in 2016 to solve social issues through logistics. AeroLion manufactures and sells drones that can accomplish barcode scans as part of its warehouse-management solution. “It is a result of years of research and development with industry partners,” says Wang Fei, AeroLion Technologies’ CEO.

The drones typically fly over barcoded products, scanning 2D or 1D barcodes, thereby saving time warehouse personnel would otherwise spend manually counting goods. However, if UHF RFID tags are attached to products, the capturing of data can be accomplished faster and without a line of site required between the drone and the tag. Although there are RFID-reading drones available on the market, they tend to be large in order to support the weight of an RFID reader, which means they are not nimble enough to be flown indoors.

The AeroLion-SATO solution aims to bring drone-based RFID reading indoors, the companies repot. The proof-of-concept took place at two warehouses, one located in Singapore and the other in Thailand. Both facilities provide logistics for home electronics products. SATO and AeroLion applied UHF RFID tags to cardboard boxes containing electronics. The boxes were stacked on pallets, two at each site, and each pallet had its own UHF RFID tag attached to it.

The goods were stacked on the racks already in use at the warehouses. In Singapore, the products were stacked at a height between 6 and 8 meters (19.7 and 26.2 feet), Chatani explains, while the tagged boxes were stacked at up to 10 meters (32.8 feet) high at the Thailand-based facility. SATO selected a small RFID reader from a partner that he says was suitable for the application based on its weight. AeroLion built a prototype drone with a load weight capacity of 1 kilogram (2.2 pounds), and the reader mounted on that drone weighs slightly less. The drone has a 70-centimeter (27.6-inch) footprint, Fei says, and is compact enough that workers could carry it with one hand.

For the proof-of-concept, the group chose to test RFID tag reading in a limited area at each warehouse. “To increase the reading accuracy,” Chatani says, “we set the drone to travel back and forth multiple times in each zone at different heights.” The drone began at a pre-set altitude at a lower level, then increased its height by 40 centimeters (15.7 inches) with each pass over the goods. The drone was tested twice—one test per day. AeroLion programmed the drone’s path at each location, and the device captured tag reads autonomously, while saving that data onboard so it could be downloaded at the end of the cycle count.

“We found the read rate varies depending on the product” packed in the boxes, Chatani says. The read rate was 100 percent with easy-to-read products, he reports, while other items that might include metals could be more difficult to read. “The read rates were not that different than you would get using a handheld reader.” The drone could accommodate any standard UHF RFID reader on the market if its weight was below 1 kilogram. “The drone itself is fully autonomous throughout the cycle counting operation,” Fei states.

The testing proceeded as planned and with few surprises, according to the two companies. Development work included adjusting the antenna’s size and orientation to gain the highest read accuracy. SATO calls the proof-of-concept a success and is now looking into further research and development before releasing the solution commercially. “We believe there is potential to expand to other types of warehouse environments to improve the safety of workers,” Chantani says.