Prediction of Close-Proximity Tire-Road Noise from Tire Cavity Noise measurements using a statistical approach

Abstract

Noise due to the contact between the tire and the road is taking more and more importance in the development of cars, tires, and road coverings. This noise influences the comfort perception of the driver and the living quality of the surrounding people and has to be taken into account during the tire development. A recent study from the Danish Ministry of Infrastructure and Environment estimated that a reduction of the Tire-Road Noise of 6 dB(A) between 2009 and 2020 could save 11 billion euros yearly by reducing the number of annoyed peopled by 13 million and the number of sleep disturbed people by 6 million.Nowadays, several methods are used to quantify the noise of a rolling tire. All of them are, however, cost- and time-expensive, lack mobility, and are dependent on the surrounding weather and operating conditions. With a self-developed measurement system, it is now possible to predict the emitted Tire-Road Noise by measuring the noise inside the tire cavity.In this study, reproducible measurements were realized on a tire test bench, where the Tire Cavity Noise and the exterior Tire-Road Noise were simultaneously recorded. The influence of many parameters, such as the driving speed, tire load, inflation pressure, and tire cavity air temperature, on the cavity noise were studied. In the end, a correlation between the Tire Cavity Noise and the exterior Tire-Road Noise was found with a prediction quality of 1.4 dB(A).This study is a first step towards reducing the time and the costs needed for standard acoustic measurements for tire homologation or for assessing the acoustic quality of different road surfaces. Our measurement method is namely not influenced by the surrounding buildings and can be used without any interference in the flowing traffic. The costs for the needed hardware are also negligible compared to the conventional exterior noise measurement systems. However, the transferability of the results on the tire test rig to field measurements still has to be checked and will be done in a future study.