Just how fast is a fast UHF RFID reader?

The latest generation of RFID readers have the capability to read in excess of 300 tags per second, but what does this mean for real life applications? In order to find out, the RFID team at HARTING joined forces with the Ignition Racing Team (IRT) of the Osnabrück University of Applied Sciences.

The need for speed

As part of the Formula Student project, the IRT develop and build their own racing cars with some very impressive performance characteristics; 1400 Nm of torque accelerates the race cars from nought to around 75mph on a 75m track. Using these cars, we ran a series of tests to determine the maximum speed a vehicle can be reliably detected using an RFID reader.

The setup for the HARTING RFID test was very simple. An RFID reader and antenna were built alongside the track and each car was equipped with an RFID transponder. In order to obtain fair results, only standard products were used and the results were evaluated in real time using the HARTING Ha-VIS middleware. The results were also written to a file in exactly the same setup as would be implemented in a real-life application.

As a warmup exercise, an electric race car was driven past the RFID antenna at 50mph. All systems functioned successfully and the car was detected and logged. In the second pass, the car was driven at close to 75mph and again was successfully detected. At this point, we had to change to a more traditional combustion engine vehicle as the electric car had maxed out. Again, we achieved successful detection, this time at 100mph.

As a final test we decided to push the RFID technology to its limits. Utilising a German roadster, the RFID equipment was tested at a startling 125mph! Even at this rapid pace, the vehicle was quickly and reliably detected. Success!

Practical applications

As well as being great fun to test, there are real practical applications for this high-speed RFID technology. For example, take the maintenance, repair and operations (MRO) for trains. Removing a train from service can be costly, so implementing RFID as part of life cycle monitoring can vastly improve reliability and dramatically shorten service times.

RFID also allows for the easy implementation of preventive maintenance, meaning faults or potential issues can quickly be diagnosed. This is where high speed reading plays a huge role; as the train passes predictive maintenance points, cycles can be monitored and any potential issues located quickly, right down to individual component level.

In addition to its speed of reading, RFID also has many other advantages over the traditional barcode reader. For example, with a barcode you need to ensure that it is completely visible and you must have direct line of sight of the code. If the barcode is damaged, the chances of getting a good read are extremely low. You also need to be within a short read distance and directly in front of the barcode to allow the 2D scanner to accurately decipher the code.

In contrast, with an RFID handheld scanner you do not need a direct line of sight. It is possible to get a good reading even if light conditions are not optimal or if the transponder is obscured (as long as it is not enclosed in metal). With an RFID transponder, you can also be further away from the item being read and you have the ability to read multiple transponders simultaneously.

Independent tests have verified the capabilities of RFID, with potential time savings of up to 94% being achieved when it comes to bulk reading.