| 1. |
- Bühlmann, Erik, et al.
(författare)
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An in-depth look at the tire rubber hardness influence on tire/road noise measurements
- 2018
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Ingår i: INTER-NOISE 2018 - 47th International Congress and Exposition on Noise Control Engineering. - : Institute of Noise Control Engineering.
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Konferensbidrag (refereegranskat)abstract
- When assessing the acoustic quality of a road pavement with the close-proximity (CPX) or the on-board sound intensity (OBSI) method, the rubber hardness of the reference tire substantially affects the measurement. Practical experience shows that measurement tires can get significantly harder within a single measurement season. This is why one would like to normalize measurements to a reference rubber hardness. The recently published technical specification defining the reference tires for CPX measurements (ISO/TS 11819-3), therefore, includes a new correction for tire rubber hardness. Early experiences with this new correction procedure raised questions about its accuracy. This paper takes an in-depth look on the influence of tire rubber hardness on CPX measurements for both reference tires P1 and H1. It analyses existing and new data and summarizes the research from several scientific contributions on this topic. It provides evidence that the effect of rubber hardness is tire specific and that separate correction factors for the P1 and the H1 tires lead to accuracy gains and improved repeatability and reproducibility of the method. The study concludes by proposing a revised tire-specific approach for the tire rubber hardness correction of CPX measurement results.
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| 2. |
- Bühlmann, Erik, et al.
(författare)
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Speed dependency of temperature effects on road traffic noise
- 2015
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Ingår i: INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering.
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Konferensbidrag (refereegranskat)abstract
- Recently, a new literature review on the influence of temperature on tire/road noise became available, based on a compilation of large amounts of data from empirical research. This review showed that the effect of temperature is roughly double of that previously assumed and taken account of in international standards. This makes temperature one of the main sources of error in measurement results. Furthermore, it suggested that an additional refinement of the correction approach may be required to improve the accuracy of measurements. As a first attempt for this refinement, this article focuses on the speed dependency of temperature effects.Some past work has detected an influence of speed on the temperature effect, but did not succeed in quantifying this influence or in describing the exact pattern of speed dependency. This work aims to fill this gap byinvestigating speed dependency of temperature effects on tire/road noiseestimating the temperature influence on noise generation mechanisms together with their change with speed, andevaluating the speed influence on overall road traffic noise by including a propulsion noise component while using a new European traffic noise emission model.The article concludes by proposing a method to deal with speed dependency of temperature effects on both, CPX (or OBSI) and SPB measurements, with the ultimate goal of increasing the accuracy of measurement results.
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| 3. |
- Bühlmann, Erik, et al.
(författare)
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Temperature influence on tire/road noise measurements : Recently collected data and discussion of various issues related to standard testing procedures
- 2021
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Ingår i: Proceedings of INTER-NOISE 2021. - : The Institute of Noise Control Engineering of the USA, Inc.. - 9781732598652
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Konferensbidrag (refereegranskat)abstract
- Air, road, and tire temperatures substantially affect tire/road noise emission. For measuring purposes, one would like to normalize measurements to a reference temperature by means of a reliable correction procedure. Current studies show that temperature effects remain an important source of uncertainty in tire/road noise measurements and tire testing, even after applying the correction terms provided in the various standards. This seems to be the case for the measurement methods used in OBSI, CPX, SPB, and various regulations or directives based on ECE R117. This paper examines a new dataset consisting of 7.5 million temperature measurements aimed at contributing to a better understanding of temperature effects and the ways they relate to air, road, and tire temperatures. It is assumed that tire temperatures are the most relevant for noise corrections; therefore, special studies are made for how tire temperatures relate to air and road (test surface) temperatures. A profound analysis is provided on how these relationships vary over different day times, seasons, and climatic regions. Based on this analysis, the authors provide suggestions for improvement of temperature normalization in current tire/road noise and tire testing standards. Special considerations are devoted to measurements on test tracks having ISO 10844 reference surfaces.
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| 4. |
- Sandberg, Ulf, et al.
(författare)
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Improving the CPX method by specifying reference tyres and including corrections for rubber hardness and temperature
- 2016
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Ingår i: Proceedings of the INTER-NOISE 2016 - 45th International Congress and Exposition on Noise Control Engineering. ; , s. 4913-4923
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Konferensbidrag (refereegranskat)abstract
- Recently completed work in the EU project ROSANNE and in working group ISO/TC43/SC1/WG33 has allowed substantial improvements to measurements made by the Close-Proximity (CPX) method, intended for measurement of noise properties of road surfaces. The paper summarizes the experimental work and describes the conclusions and implementation in ISO/FDIS 11819-2 (the CPX method) and in the supporting ISO (draft) Technical Specifications 11819-3 about Reference Tyres and 13471-1 about Temperature Corrections.In the Reference Tyre specification, two reference tyres are defined, of which one is the 16'' SRTT specified in ASTM 2493-14 and the other is a commercial light truck tyre. Both tyres have been tested with respect to correlations with SPB (pass-by) measurements and found to represent car and truck tyres, respectively, in this particular application. To account for reasonable ageing and minor production differences, a correction for rubber hardness is specified, in order to normalize measurement results to tyres having reference hardness. The Temperature Correction specification includes temperature coefficients that are used for normalizing noise levels to an air reference temperature of 20 degrees C. The coefficients relate to driving speed by a simple equation which is different for three categories of road surfaces, which are specified in the document.
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| 5. |
- Schlatter, Felix, et al.
(författare)
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Project STEER : Improving the EU Tyre Noise Label
- 2022
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Konferensbidrag (refereegranskat)abstract
- Tyre/road noise is the dominant component of overall vehicle noise at medium and high speeds and for cars even at relatively low speeds. Consequently, road traffic noise can be reduced with the proliferation of quieter tyres. One way to achieve this is to give the tyre noise label greater attention among tyre and transportation consumers. Hence, the STEER project has evaluated the relevance and performance of the noise part of the European tyre label, looking at how it works in practice, analysing its uncertainties and suggesting how it can be improved. Its main finding is that the uncertainties in the measurement of noise level for the label are too high to be acceptable. This paper focuses on the solutions offered by STEER for an improved tyre label. With four main improvements, the overall uncertainty of the current procedure can be halved. A few possible future strategies to increase the market share of quieter tyres have been analysed and their effects quantified. If the tyre noise label is improved and the market share of quieter tyres can be increased, as project STEER proposes, area-wide reductions of up to 3 dB in road traffic noise emissions compared to the present situation are possible.
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