The University of Birmingham doctoral researcher discusses how piezoelectric transducers can be used to measure interlayer tire strain.
What is the background to your presentation, ‘Tire strain measurement system using piezoelectric elements’, at Tire Technology Expo 2017?
Further to the advances in monitoring of tire pressure and temperature, tire strain is the next parameter to be monitored in an intelligent tire system. Strain sensors can provide sufficient information to enable drivers to improve driving performance and reduce tire rolling resistance. Tire strain monitoring could also be used to improve vehicle safety as any critical strain values can be communicated to the driver as the tire is in movement. Piezoelectric strain sensors – which are used in this research – can provide dynamic strain measurement that is compatible with the viscoelastic tire strain behavior.
Why is this important for the industry?
In an intelligent tire system the tires must be able to adapt to the road and the driving conditions. Tire strain monitoring is crucial in order to sense the road conditions and tire behavior. Monitoring tire strain can also provide important data for tire manufacturers to develop tire designs and reinforcement structures. Road surface conditions can be also monitored and maintained or improved. It’s also important for self-driving cars in which this technology can provide sufficient information to the main car’s computer to change the driving mode.
What are the challenges in using piezoelectric transducers to measure interlayer tire strain?
The main challenges are how to store the swarming and rapid strain data and transmission and analysis. To establish a feasible monitoring strategy, tire strain sampling rate needs to be at least 10kHz at 30mph in order to gather sufficient strain data across the contact patch. In addition, it is necessary to test a range of tire models to accumulate tire strain behavior patterns within a range of driving and load conditions. Strain data collected from vehicles should be compared with strain pattern data obtained by tire and vehicle manufacturers to establish the best driving behavior. Also, attaching the tire strain sensor to the inner tire surface is still a challenge where tire strain is relatively huge.
How could this be taken a step further?
This research can be developed using more compact and robust electronics that can collect, process and transmit tire strain data. We also intend to carry out more on-road tests to monitor tire strain behavior over a range of driving and load conditions rather than using a tire test rig only.
Ammar Kubba, a doctoral researcher at the University of Birmingham in the UK, will present on Day 1 of the Tire Technology Expo Conference in the Scientific & Technical Conference at 10.15am.