Because the tires on your car are its point of contact with the road, they can provide useful safety information like how fast you’re driving and whether the road is slippery. A new research project at Virginia Tech will make accessing, and using, that information much easier — which could make driving much safer.
Researchers at Virginia Tech, Penn State University, and 12 industry partners are collaborating on a $1.2 million National Science Foundation-funded project to integrate sensors into car tires.
The ceramic sensors will gather information about road conditions and the health of the tire, and transmit that information wirelessly to the car’s control systems. The team will develop new manufacturing techniques for direct sensor integration into the tires.
Saied Taheri, an associate professor of mechanical engineering in Virginia Tech’s College of Engineering and the director of the Center for Tire Research (CenTiRe), will be the lead investigator.
For several years, Taheri has been working on gathering data from tires using an attached sensor; the new project will expand on that research by incorporating multiple piezoelectric sensors into each tire through direct deposition techniques. With many more data points available per revolution, researchers can extract systematic information.
“That gives us a much broader way of looking at those interactions between the tire and the road,” Taheri explained. “All of these parameters that we’ve been assessing with one sensor, we will be able to assess much more accurately.”
Piezoelectric sensors convert physical inputs, like changes in pressure, temperature, and acceleration, to electrical signals. In a tire, those signals could convey information about the friction between the tire and the road, the car’s acceleration, and the tire’s air pressure and structural integrity.
If this data could be transmitted wirelessly to the car’s computer, the car’s existing control systems could automatically adapt to maximize safety.
“There are many control systems in the car, and this can be integrated into all of them to adjust them accordingly — if you’re on rough terrain, if you’re on snow, if you’re hydroplaning,” Taheri explained.
For example, adaptive cruise control, which adjusts the car’s speed to maintain a safe distance from other vehicles, could incorporate road-condition data into algorithms calculating how quickly or slowly it could safely modulate speed. Anti-lock brakes and active suspension systems use the data similarly.
The Broadband Wireless Access and Applications Center is collaborating on the project to develop the wireless technology; the Center for Energy Harvesting Materials and Systems is also involved, to come up with a way to use the tire’s own motion to power the sensors and transmission systems.
Because there are no methods currently available for integrating piezoelectric sensors into tires during the manufacturing and curing process, the team will use additive manufacturing — also known as 3-D printing — to print the electronic components onto finished tires.
The biggest challenge, Taheri said, is that the shape of a tire doesn’t lend itself well to 3-D printing. So the team will start by printing and testing the sensors on flat tire segments, and then move on to the small inflatable tires on the lab’s robotic vehicles.
Once the sensors, wireless systems, and data-processing algorithms have been tested using these miniature vehicles, the tire companies involved in the project, including co-principal investigator Bridgestone, will conduct tests on full-size tires. The project is scheduled to run for two years.
The team is also investigating printing piezoelectric sensors on the car’s seatbelts, where they could measure the driver’s vital signs and movements, potentially detecting a distracted or ill driver before he causes an accident.
“The goal is to be able to contribute to the safety of transportation,” Taheri said.
The safety benefits would extend beyond the sensor-enabled vehicle itself: the wireless systems transmitting data from the car’s tires to its computer could share data with other vehicles (V2V) and with the broader communications infrastructure (V2I), allowing additional users to access this information and dramatically increasing the potential impact.
Shashank Priya, a professor of mechanical engineering and the Faculty Director of Sustainable Energy at the Institute for Critical Technology and Applied Science, assembled the project team.
“The interdisciplinary team comprises three National Science Foundation Industry/University Cooperative Research Centers and one Engineering Research Center,” Priya said. “They bring together the right expertise and background to address a comprehensive set of technical barriers and make a fundamental breakthrough in developing intelligent tire systems.”
The tire project is designed with an eye towards the rapidly developing phenomenon of “Intelligent Transportation,” which will help people use transportation networks more safely and efficiently.
Over the last few years, advances in electronics, data processing, and communications systems have brought intelligent transportation much closer to reality. So, Taheri said, “we’re looking ahead.” Tires, it turns out, can be an important piece of that puzzle.
“When most people look at a tire, they just think ‘black doughnut’ — but there’s so much you can do,” he said.