Based on Models and Vehicle and Tyre Measurements

Tyres make the only contact between vehicle and road, influencing vehicle dynamics significantly with their specific characteristics. Braking performance is a key requirement that must be tested and ensured during the tyre development process. This is generally accomplished by conducting braking manoeuvres with the target vehicle, yet this instead investigates the tyre as part of an overall system and not the tyre’s properties themselves. To gain a deeper understanding of the tyre characteristics responsible for braking performance, it is necessary to utilise a method that provides quantifiable characteristic values while considering relevant external influences.

The tyre characteristics are investigated using two different measurement methods and divided into steady-state and dynamic values in the project. Concerning steady-state tyre behaviour, force-slip curves measured by a skid trailer and a test vehicle are particularly important. Dynamic tyre behaviour during braking manoeuvres is investigated by means of accelerometers fixed to the inner liner of the tyres. Specifically, the shape of the contact patch and the transition from adhesion to sliding, which the accelerometers can detect, are identified as relevant characteristics and correlations to the steady-state properties are analysed.

Figure 1: Tyre sensor measurement-setup

The MF tyre model, the tyre brush model, and the LuGre tyre model are utilised for these investigations. External influencing factors have to be considered for the derivation of steady-state and dynamic characteristic values. These include tyre temperature, velocity level, road surface, ABS control system, brake system, and the interaction between vehicle and tyre. Applying this method in the tyre development process may allow for an integrated evaluation of tyres' braking performance.

References

Degenhart, Fabian, Johannes Edelmann, and Manfred Plöchl. "Application of tire sensors for an integrated approach to evaluate longitudinal tire characteristics for braking performance., opens an external URL in a new window" Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 235, no. 2-3 (2021): 627-638.

Researcher

• Fabian Degenhart

Project Partner

• Porsche AG