TYRE NOISE MEASUREMENTS USING THE PASS BY AND CPX TRAILER METHOD, PROPOSAL TO ALTER THE TESTING SURFACE

摘要

Tyre noise measurements with the "Pass By" and the "Close ProXimity trailer" methods are heavily dependent on the texture of the surface, they have been performed on. ISO 10844 is trying to implement all the necessary parameters in order to obtain a reference testing surface, but even though this standard is very detailed, most tyre noise measuring projects, keep their reservations concerning the validity of the data, due to the testing surface characteristics. Furthermore it has been proven that testing surfaces are aging, time and traffic dependent, thus affecting the measured results. Directive 2001/43/EC of the European parliament is focusing on the Pass_By noise measuring procedure, taking into account the surface type and surface condition to extract the noise data of each tested tyre. In order to make more valid tyre noise measurements in the future and be able to compare the radiated sound of different tyres, one has to eliminate the varying acoustic behaviour of the testing surface. This paper introduces such a new "standard" testing surface, able to be easily manufactured worldwide and able to produce comparable results per tyre. The scope is to provide a non aging reference surface on which comparable tyre noise data can be acquired, so they can be safely stated on the "tyre noise label" of each new tyre. By using this proposed reference surface, the noise behaviour of the tyre's tread design can be studied, not taking into account the varying surface interaction.