Confidex Drives Tire Tracking With Small RFID Tag

By Claire Swedberg

The company's TireTag is 67 percent smaller than standard RFID tags and offers a read range of up to 3 meters, enabling businesses to more easily build RFID into each tire in order to track its operation.

Smart industry and mobile technology company Confidex has released its new TireTag, which is designed to be smaller and more flexible than competing UHF RFID tags, the firm reports, and to offer a longer read range. According to Confidex, the product enables tire companies and fleet managers to uniquely identify tires, wherever they may be in their lifespan, via an RFID reader.

With a built-in omnidirectional antenna, the company reports, the tag provides a 3-meter (9.8-foot) read range and responds to interrogations from multiple directions so that operators can track tires via a handheld reader, whether in a warehouse or on a vehicle. The tag is designed to be built into a tire during the assembly process. That means it can withstand heat and pressure, as well as the bending that sometimes results during vulcanization, before the tire is sold for use on trucks or cars.

Confidex's TireTag enables tire companies and fleet managers to uniquely identify tires.

Jiangsu General Science Technology Co., located in China, has recently completed a pilot of the tag, while several tire companies currently have pilots under way or nearing completion. Confidex plans to demonstrate its new tag at RFID Journal LIVE! 2020, which will be held in Orlando, Fla., on Apr. 28-30.

The round passive UHF RFID TireTag MR6-P tag measures 40 millimeters (1.6 inches) in size—approximately 33 percent smaller than other comparable tags on the market, which typically measure about 60 millimeters (2. 4 inches), according to Confidex. Thanks to the omnidirectional antenna, it can be read from both radial and diagonal applications, says Will Deng, Confidex's CTO. That means the tag could be read via a reader passing a vehicle-mounted tire within a yard or a parking area, even if the vehicle is moving, and it could also work if tires were stacked in a warehouse. Additionally, the tag can be interrogated from a fixed reader antenna installed in the ground or under the surface of a yard or roadway.

RFID technology, whether in the tire industry or other sectors, is transitioning into item-level tracking, says Joe Hoerl, Confidex's VP for the Americas region. "We see a natural progression toward the need for serialized IDs of products," he explains, rather than containers of products. "The technology is better. Tags are smaller, cheaper and faster. So we are seeing a movement into serialization of the individual item."

With that in mind, tire manufacturers have increasingly been either piloting or launching RFID systems for tracking truck tires. Confidex has been in the tire-management space for more than a decade. In 2008, the company offered a product for the management of tire materials known as the Confidex Cruiser Tire Label (see At Nokian Tires, RFID Keeps Treads on Track). "We have spent several years engineering this latest tag design," Deng states.

The TireTag has been designed to overcome some existing challenges related to the embedding of RFID during the tire manufacturing process, Deng notes. The conditions to which the tags are exposed, as well as the materials in the tires and rim, can affect transmissions. The initial challenge comes with the placement of tags in a tire's sidewall while assembly takes place. Each tire undergoes vulcanization, he says, which leads to temperatures above 220 degrees Celsius (428 degrees Fahrenheit), as well as high pressure. Tire manufacturers have found that existing tire tags with 3D antenna structures could enable air bubbles to be trapped in the tag during this process, Deng adds.

"We tried many different types of antenna design," Deng says, which resulted in a 2D antenna structure with omnidirectional functionality. That structure prevented air bubbles from collecting around the antenna, while also making it more flexible so it could sustain the stretching and bending that can occur during manufacturing. The antenna is designed to withstand temperatures of up to 250 degrees Celsius (482 degrees Fahrenheit).

During vulcanization, Deng says, stretching requires that the antenna be flexible, and the materials in the tire's rubber and rim pose a challenge as well. That's especially true when tag position may shift. "Sometimes it's very hard for a manufacturer to control tag position," he states. That means the tag can end up being embedded close to the metal rim, which affects its performance, and the metal built into truck tire rubber can also limit performance. Because of these conditions, he says, tire tags could traditionally be read from a distance of about 20 to 30 centimeters (7.9 to 11.8 inches) at most.

The tire industry has been seeking strong RFID tag performance from a range of about 1 meter (3.3 feet), according to Deng. For instance, if tires are stacked in a warehouse, or if double tires are mounted on a vehicle, existing RFID tags will not offer a sufficient read range. The TireTag can transmit a signal to a distance of more than 2 meters with a handheld reader and up to 3 meters with a fixed model, which Deng says is up to three times' customers' expectations. The core feature that makes the tag smaller and high-performing, he explains, is in how the antenna impedance matches that of the tag chip. "We improved the impedance-matching design on our antenna," Deng states, enabling a longer range and more stable performance.

The company has also launched a testing method that occurs before tags are sent to the manufacturer, in order to ensure that they will operate properly once embedded in tires. The firm simulates the material of its tires and tests the tags in that environment before sending them to a customer. That, Deng says, ensures that they do not undergo the process of tag embedding but then fail to perform properly. "We designed very special test equipment to test the performance before [the tag ends up in] the tire," Deng says, adding that this can guarantee tags will perform well even after being embedded.

The omnidirectional functionality, Deng says, ensures that companies will not need to install multiple tags within each tire to be sure they can be read from any angle. Some companies have embedded multiple tags on each tire so that they can be read at any angle. "With our design, because of omnidirectional capability, that isn't necessary," he states.

A number of companies began piloting the TireTag in 2018, and these firms have taken their time to ensure that the tag continues to perform as each tire is used throughout the course of several years. For instance, one business installed the tag in approximately 300 tires, then proceeded to capture tag reads periodically as the tires were used in a real-world environment.

The value of tire tagging is multi-fold, Hoerl explains. Some of Confidex's customers are rental agents that rent tires to companies operating fleets of vehicles. With each tire tagged, these companies can read data about a given tire when providing it to a customer, as well as track its usage and condition, then receive the tire back, retread it, and continue to manage its use and condition through the tire's lifetime.

The data that can be collected from RFID tag reads is of value to users as well as the entire tire industry, Hoerl notes. For instance, operators can capture tag reads on vehicles during scheduled maintenance or inspection, as well as update information about usage and store that data in management software. That information provides a history not only of each tire's mileage and its condition over time, but also where on a particular vehicle that tire was mounted. Such historic details enable a better understanding of tire performance under specific conditions. If a company puts more pressure on tires by carrying heavier loads, for example, that data can provide insight regarding the best conditions for improving performance.

With such data, Deng reports, companies can better understand how a particular tire was used, along with when it may need to be replaced or retreaded, thereby preventing unnecessary replacements of tires that may still have more life in them. The tags are also useful for recalls, Hoerl says, to ensure that tires that should not be on the road are removed during maintenance or inspection.

When it comes to tire manufacturing, Deng says, some companies are embedding the RFID tags manually. Most manufacturers in China, for example, employ a manual assembly process for tires, so they can simply add the RFID-embedding task to their existing process. Others, such as some manufacturers in Korea, are automating the assembly process and are then adjusting their equipment to enable the addition of RFID tag embedding. Since the pilots began, he reports, the feedback has been positive. The tags are working, he says, with no reported failures.

The TireTag has an IP68 rating against liquids and dust, and is designed to provide resistance to common chemicals and ultraviolet exposure. The tag is compliant with the ISO 20909 and ISO 20910 standards.