The phrase “where the rubber meets the road” refers to the friction point when a situation gets serious. When it comes to track racing, the rubber (the tires) are the critical point of contact between the asphalt and the car itself. Tires make all the difference between a strong finish at the checkered flag and a horrific slide into the wall. And if they’re not working together, the whole system falls apart.
Knowing this intimately, Italian tire company Pirelli teamed up with juggernaut technology company Bosch to jointly develop and create a tire communication network. As such, Pirelli “Cyber Tire” contains a sensor that gathers and transmits data to the car, creating a connection that channels critical information. In essence, these sensors take a look at the temperature of the tires, tire pressure, the status of the road, and more, and advise the car’s controllers about adjustments that need to be made.
It’s as if each tire is an individual athlete, checking in with its sensors and chiming in with a “Put me in, coach”; or conversely, “We might need to take the intensity down a notch.”
Think way beyond tire pressure monitoring systems. This is the next level of information tires can collect, and the difference is akin to comparing a flip phone to a smartphone.
Tires that communicate more than just pounds per square inch
Pirelli began working on finding ways for its tires to “speak” directly to the car’s onboard computer nearly 25 years ago. However, it’s only in the last year that the company developed its partnership with Bosch. Collaborating with Bosch Engineering—which is well respected in the prestigious world of supercars like Ferrari, McLaren, and Aston Martin and also works closely with typical commuter car manufacturers—the tire manufacturer harnessed the power of the technology giant’s high-end controllers.
“The aim was to get information from the tire, as the tire is the only point of contact between the car and the ground and where all the forces are being transferred,” says Pierangelo Misani, Pirelli senior vice president and chief technology officer. “It’s a source of potential information that is extremely useful for safety and efficiency.”
Thanks to the evolution of batteries as they have become smaller and more mobile, putting a miniaturized power source inside a tire is not the challenge it once was. That’s key for this application, because any added mass inside a tire can generate imbalance. Imbalance can cause vibration, which affects comfort and safety. It’s important to have a system that is extremely light, Misani says, and still includes components like the accelerometers, chip set, pressure sensor, temperature sensor, and the battery. On top of that, this set of elements has to last for at least the life of the tire.
Operating in a potentially hostile ecosystem
There are plenty of sensors in a car, some protected from the elements and some deliberately exposed to water, wind, and drag force. But inside a tire, an entirely different ecosystem exists. After all, it’s inflated with air, which introduces a humid environment. Second, it rolls and changes shape, flattening with the weight of the vehicle.
When the sensor rolls around to the contact patch, or where the tire makes contact with the ground, it has to decelerate and then re-accelerate. That’s because of the difference in the diameter when the tire is rolling; the distance from the hub is smaller.
“We are speaking of enormous acceleration, plus the sensor inside the tire may go over bumps, a pothole, or even off-road,” Misani says. “So you understand the components have to be miniaturized and light, but they have to be also extremely resistant to the extreme conditions that the tire is posing to them.”
Sensors in tires aren’t new, but Pirelli’s new agreement with Bosch means that the data of the tire is now directly transferred into the controller in real time and used to control the car. What is totally new is that the sensors are actively contributing data to the controller to control the stability, braking, and traction of the car to create the best outcome for that moment, Misani explains. For instance, if the anti-lock braking system is active, the car’s computer system doesn’t know the tire speed or conditions of the road at that moment or whether the tire slippage is negative or positive. Without this integrated system, the ABS has to guess at the conditions and might not maximize the capabilities of the tires.
Pirelli aims to address hydroplaning, a dreaded road condition that happens when your tires can’t channel enough water away from the tread and vehicle control becomes a major issue.
“Hydroplaning means that the contact patch becomes shorter and shorter until it’s lifted,” Misani describes. “It’s like a boat that is lifting from the water, causing you to lose contact with the ground. The less contact with the ground, the less capability you have to accelerate, brake, or steer. With the sensor, we are able to detect if there is hydroplaning.”
Pirelli’s CTO also says another feature the company is working on is algorithms that can predict or to detect the effective wear rate of the tire and at which stage of its life the tire is.
Sharing the technology
While hypercar builder Pagani is the first to use the integrated sensors in its 850-horsepower Utopia Roadster, Pirelli has set its sights on a much broader application.
“In the Pagani Utopia Roadster, we are able to actively send the data from the sensor to the receiver that interacts with the controller system of the car and actively tells the ABS, stability control, and the traction control how to get the best response for that condition,” Misani says. “It was the first proof of concept that we can show to other OEMs to show that it works.”
Ultimately, Misani says Pirelli wants to share this technology with other manufacturers.
“This is the future. We are the first one to have it, but we don’t want to keep it only for ourselves,” he emphasizes. “It’s a way to improve safety and has to be available also to others.”
