Goodyear and TNO enhance vehicle safety using tyre intelligence

The essential role of tyres in smart vehicle safety

Cars have evolved from vehicles that only monitor their own state to ones that observe their environment and enhance safety with intelligent support and automated features.

‘However, despite sensors and smart algorithms that help control the vehicle, the only contact with the road is still through four hand-sized pieces of rubber’, says Ron Wouters, System Engineer at TNO. Tyres are therefore an important part of vehicle safety as they contribute to steering and braking capability. Traction loss due to tyre wear, or poor road and weather conditions, can compromise safe operation of driving systems.

Wouters: ‘Tyres can have a big impact on vehicle behaviour and safety when properly maintained and operated. Variables like tyre type, size, degradation, and inflation influence handling and braking. Safety features are designed for a narrow operating window, making it even more important to anticipate to actual conditions. Tyres can provide valuable input to vehicle systems, allowing them to account for actual tyre, road, and weather conditions, and with that enhance safety.’

Using ABS as first test case

With their SightLine programme, Goodyear aims to explore innovative applications for intelligent tyres. TNO has a longstanding R&D relationship with Goodyear, jointly contributing to significant innovations in modern tyre technology. In 2021, this fruitful collaboration was revived with joint research on tyre intelligence. Ron Wouters noted, ‘This research requires both knowledge of tyres as well as application expertise, and at TNO we offer both. With Goodyear, we have a very open and transparent collaboration.’

To demonstrate the potential benefits of tyre intelligence for the effectiveness of safety systems in vehicles, Goodyear and TNO chose a relatively straightforward use-case: the Anti-lock Brake System (ABS). All modern vehicles are equipped with ABS, which maintains steering capability and shortens brake distance by preventing the wheels from locking under heavy braking conditions. In production vehicles, the ABS uses a fixed parameter set that was defined during development through extensive testing. Robustness is introduced by implementing adaptivity during system activation.

These parameters in combination with the adaptivity aim for optimal performance across different tyre types and conditions, including various road and weather conditions. Ron Wouters: ‘However, due to this strategy, the system cannot fully maximise braking capability. The objective of this research project was to achieve maximum performance while using tyre information that was determined by the intelligent tyres a-priori to the ABS brake interrupt.’

Promising test results

For this purpose, Goodyear and TNO have developed a demonstration vehicle to showcase an upgraded ABS controller that uses data from intelligent tyres. Ron Wouters noted, ‘These tyres provide both static details such as tyre type and factory characteristics and dynamic information like, temperature, wheel load, and actual characteristics. With this information the ABS controller minimises rotational wheel acceleration and maximises wheel slip to utilise the largest grip potential in all heavy braking circumstances.’

The Volkswagen Golf demo vehicle was put through an extensive and demanding test programme, including straight-line braking tests to a standstill on dry and wet asphalt with various tyre types, both new and worn. ‘First, we measured the original ABS performance with the reference tyre, then with the same tyre we tested the TNO ABS. We then repeated the test with three other tyres, new and worn. The experimental results show that intelligent tyres can significantly enhance ABS performance.’

‘The tuned controller partly compensates for the loss of traction due to tread wear or demanding road and weather conditions, resulting in significantly shorter stopping distances. The search space to find optimal parameters at the beginning of the ABS’ braking event is reduced, leading to improved brake performance.’

ABS is just the beginning

Apart from the significant safety benefits, TNO foresees an interesting economic advantage for the OEMs as well, because the intelligent tyre ABS reduces the need for extensive tuning and testing across various vehicle configurations. The results of the ABS research project were first presented to the world at CES in Las Vegas and more recently at ATZlive’s Chassis.tech plus in Munich, impressing an audience of automotive OEMs and Tier 1 suppliers.

‘While this project marks an important step for demonstrating tyre intelligence, it’s just a first step,’ Ron Wouters explains. ‘The principle of using data from intelligent tyres to improve the effectiveness of vehicle systems can also be applied to a whole range of ADAS and autonomous safety systems. A logical next step could be to research Autonomous Emergency Braking (AEB), optimising and predicting brake distances under various weather and tyre conditions, or Automated Emergency Steering (AES), which automatically steers to help avoid accidents when a potential collision is detected.’

Intelligent tyres crucial for CCAM

While proving to be very useful for today’s vehicle safety features, intelligent tyres may prove invaluable for tomorrow’s Cooperative, Connected, and Automated Mobility (CCAM), Ron Wouters explains. ‘In current traffic, drivers anticipate challenging conditions, knowing braking distances increase on slippery surfaces. Human drivers increase following distance while driving in rain, ice, or snow conditions and reduce speed in corners, considering road condition and vehicle load.’

‘Automated vehicles must also adapt their driving style to adjust to these changing conditions without human insights. Intelligent tyres can provide this accurate and real-time input for determining driving strategies based on actual conditions. The industry currently focuses mainly on system design, but we have to ensure that automated systems adapt to varying traffic situations, weather conditions, and tyre wear. Intelligent tyres will become a crucial ingredient for safe automated driving.’