Drone-Based Relay Technology For Passive RFID Inventory Management And Warehousing

In an era of mega-warehouses and distribution centres (think Amazon, Walmart, Target, Tesco, NASA, Boeing, Airbus), keeping track of millions of assets, products, parts and components, and taking stock of inventory, can be a consuming job, even with the help of RFID.

One of the biggest challenges for these expansive operations is the short read-range of passive (battery-free) RFID – which tend to be the tag of choice as they are one of the most cost-effective auto-ID solutions for high-volume applications. This range is reduced even more if the RFID tag is buried beneath or behind something, or in a radio frequency blind spot. As a result, inventory management processes can still require warehouse staff to move around with wearable, hand-held or forklift mounted readers.

Due to these challenges, efforts have been made to look for alternative solutions such as vision-based systems, however, these also have their limitations and many require line-of-sight. Recently however, researchers at MIT have come up with a novel way to circumvent these issues with a system called RFly. RFly is a drone-based relay technology for passive RFID systems – for which it has been purpose-built – whereby the drone acts as a ‘relay’ between the tags and the reader.

How RFly Works

The concept itself is fairly simple, although the algorithms behind it are not [ if you are interested in this aspect you can read about it here ].

In short, when an RFID reader transmits a query, the relay on the drone picks it up and forwards it to an RFID, and then forwards the RFID’s reply back to the reader, so that as the drone flies, it scans the entire warehouse, extending the range of already deployed infrastructure and eliminating blind spots.

It also means that drone technology can be integrated utilising existing RFID warehousing and inventory management systems, further extending return on investment.

MIT are hopeful that this methodology could transform asset inventory management by solving a number of important safety and technical issues, whilst keeping total cost of ownership low.

RFly Improves Accuracy, Read-Range, ROI, And Safety

MIT’s experiment with RFly has demonstrated decent results.

Firstly it resulted in significantly extended read ranges. MIT were able to demonstrate 100% read rate of passive RFID’s up to and over 50 meters away in non-line-of-sight environments. This represented a 10X gain in read range compared to scenarios where a relay methodology was lacking.

Secondly RFly also improved RFID tag localisation accuracy in that the system was able to locate passive RFID tags within an accuracy of 19cm.

Thirdly, RFly also allows operators use smaller and safer drones than previously possible.

Whilst there are RFID drones on the market which can solve the challenges associated with passive RFID, typically they require cumbersome RFID readers to be attached to the body of the drone. This means that the drone has to be large enough to support the size and weight of the additional payload, making them hazardous should they crash into a person.

However, since relay hardware is typically smaller, more compact drones can be used which don’t pose as much of a safety risk, and which also have the added benefit of being able to fly into confined and hard to reach spaces.

It will be interesting to follow the development of this prototype – one that combines the agility of drones with the auto-ID capabilities of passive RFID – and see how well it performs in real-world environments. The initial MIT experiment operated with just a single drone relay but in the future it might be advantageous to extend the system’s capability to ‘swarms’ of drones.

In the meantime, if you would like to learn more about RFID-based systems for managing asset inventory and warehousing operations, please reach out to us on +61 (0)2 9998 9000 or sales@relegen.com. Leverage our proprietary enterprise asset intelligence platform, unique item-level serialisation technology, and extensive Defence and industry experience for your business application today.