A new RFID reader from U.K.-based technology company PervasID is offering bidirectional detection of moving tagged items with what the company claims is more than 99 percent accuracy. The Flow Ranger is designed not only to read tags in highly dense environments, such as one containing a pallet loaded with tagged goods, but also to identify the “flow” of those tagged items as they move through portals or past the reader. The product was commercially released at the recent RFID Journal Virtually LIVE! 2020 conference and exhibition.
The system can interrogate up to 400 tags per second, according to Sabesan Sithamparanathan, PervasID’s founder and CEO, and is designed to help companies better identify the direction in which goods, assets or individuals are moving. The technology can also filter out stray reads that have challenged stores, hospitals, warehouses and other RFID technology users in the past.
PervasID’s Flow Ranger
The Flow Ranger is designed to reduce body shielding so that the system can be used reliably at stores for shrink reduction. To eliminate cross or stray reads, as well as to accurately detect direction, the device uses a patented technique that Sithamparanathan calls “virtual RF boundaries.” The system reduces the number of cross-reads by enabling users to set up a read-area boundary within which tags will be read. These virtual RF boundaries enable the bidirectional detection to determine which way a tag is moving and then share that information.
Algorithms in the reader accomplish the directional data capture. As a tag moves from one side of the virtual boundary to the other, its signal can indicate its location and direction. This direction-of-travel algorithm, Sithamparanathan says, can accomplish the direction detection with any standard UHF RFID antenna. “This is the result of a breakthrough innovation for us,” he states.
PervasID was founded by University of Cambridge researchers, and its technology is based on a distributed antenna system (DAS) that transmits RF signals across wide beams that fill a zone in order to detect very precise locations. Conventional UHF RFID portals used at a store’s entrance and exit, or in a warehouse portal, can provide reasonable read accuracy in less tag-dense applications, Sithamparanathan explains, though they do not offer accurate directional data, he notes. “Our innovations focus on achieving near-100 percent accuracy,” he states, “whether the tag is static or moving.”
Traditionally, conventional readers have required multiple antennas to identify a tag’s directional movement. For instance, several sets of antennas might be installed—one inside a doorway and another outside. The order in which the antennas capture the tag ID indicate its direction. However, Sithamparanathan notes, such a setup has limited effectiveness. The conventional way of tracking direction with multiple antennas provides only 80 percent direction accuracy, he estimates, whereas “Flow Ranger will get accuracy to near-100 percent.”
Additionally, Sithamparanathan says, many stores and other companies have been challenged by the problem of how to capture stray reads from tags in the surrounding area. If goods are displayed or stocked near an entrance or are carried near a doorway, the system can capture tag reads of items not actually leaving the premises. Similarly, at warehouses, where multiple dock doors are used for loading and unloading goods, readers capture stray reads at times, so the system might not accurately identify which products move through which doors.
According to Sithamparanathan, near-100 percent directional accuracy is important to many companies; he cites distribution centers as an example. Such companies have indicated a desire to see precisely what is passing through their dock doors in real time. If they can capture that data with fewer staff members in the loading area, he explains, that not only makes the process more efficient, but also reduces contact between workers—which is vital during the COVID-19 pandemic. “There’s a huge interest to see and automate as much as they can with minimum staff onsite,” he states.
Sabesan Sithamparanathan
On the other hand, Sithamparanathan notes, stores are interested in seeing what is really leaving their building. Conventional electronic article surveillance (EAS) systems do not enable managers to view what has exited the premises. As such, stores are interested in replacing conventional EAS gates so they can know which item is being removed and automatically update their inventory data. However, he adds, “Until now, the reason they haven’t installed [RFID gates] is the cross-read problem.” The new readers offer reliable reads even through the human body, he says, making it difficult for individuals to block a tag’s signal as they leave a store.
Several companies are trialling the Flow Ranger readers for industrial and healthcare applications, Sithamparanathan reports. Industrial sites are tracking tools, supplies or assets moving into or out of an assembly area, or from one station to another. “In that way,” he says, “you can understand the flow of each item.” Hospitals, for instance, are interested in monitoring the movements of high-value medical equipment and PPE equipment. Several NHS Trust hospitals in the United Kingdom are using PervasID’s overhead Space Ranger reader in strategic locations for real-time inventory monitoring systems.
Some of these hospitals are piloting the Flow Ranger to provide additional views into the movement of goods. For example, a Space Ranger in a storage area can capture real-time data regarding which goods and supplies are located in storage. Medical devices removed from storage can then be tracked via the Flow Ranger at key portals around the hospital, where exact location information is less important, but general flow data can identify where items move during patient care.
At least one bank is testing the Flow Ranger to manage the flow of staff members throughout an office building, and the system could provide data for contact tracing as well. Trials began during the past two months, Sithamparanathan says. Since then, he adds, “Feedback is that it performs with 99-plus percent accuracy.” Several businesses have indicated that they plan to expand to permanent deployments.
“I think this will truly transform automatic inventory and asset management in all these sectors,” Sithamparanathan says, whether the reader is used in retail, logistics, healthcare or industrial settings, or in another vertical market. “Up to now, they were very limited by conventional reader performance.” In most cases, companies already using UHF RFID portals that wish to upgrade to the Flow Ranger can replace their existing readers, though the antennas can remain. “All they need is our reader and our API to integrate with their software. It’s a very straightforward, plug-and-play system.”