Experiences with the new ISO 10844:2011 specification of test tracks for measuring noise emitted by road vehicles and their tires

摘要

International standard ISO 10844 is applicable to test tracks used for evaluating vehiclernexterior (pass-by) noise. The objective of the standard is to provide a high degree ofrnreproducibility between different test tracks. Toward that objective, the standard specifiesrnproperties of the test track to (a) ensure that noise propagation is not significantly affectedrnby the surface, and (b) minimize the variability of tire-pavement noise generation. Thernmost recent version of ISO 10844 was published in 2011. There are significant changes inrnthe methods of measuring the pavement’s acoustic absorption and texture properties, asrncompared to the 1994 version of the standard. Acoustic absorption affects noisernpropagation over the surface, and the standard now requires the two-microphonernimpedance tube method measured in situ. Pavement texture affects tire-pavement noiserngeneration, and the standard now specifies laser-based profiling methods. This paperrndiscusses the authors’ experiences with testing according to the most recent version of thernstandard. Advantages and benefits of the new test methods are described, as well asrnpractical techniques to help ensure valid measurements. In addition, this paper exploresrnthe possibility of supplementing the ISO 10844 measurements with standard tire-pavementrnnoise testing using the On-Board Sound Intensity (OBSI) method. This additional testrnprovides a direct measure of the tire-pavement noise response, which can be compared tornthe pavement texture being used as an indirect indicator of this response. The OBSIrnmethod also allows for a measure of the variability of tire-pavement noise along the lengthrnof the test track (spatial variability). The results of both tire-pavement noise and texturernmeasurements from various test tracks are presented in order to demonstrate whatrncorrelations can be made, including the means to improve the characterization of thernspatial variability.