Acoustic response variability in automotive vehicles
Acoustic response variability in automotive vehicles
复制标题
DOI：
10.1016/j.jsv.2008.09.029
复制
发表时间：
2009-03-20
影响因子：
4.7
通讯作者：
Ferguson, N. S.
中科院分区：
文献类型：
--
作者：
Hills, E.;Mace, B. R.;Ferguson, N. S.
对大量汽车的音频响应的一系列测量结果进行了统计分析：一款小型掀背车，同时具有三门（411 辆）和五门（403 辆）衍生车型以及中型家庭五门汽车（316 辆）。这些套件包括各种规格的车辆、发动机、变速箱、内饰、车轮和轮胎。测试在半消声室中进行，并记录了温度和湿度。对每辆车进行了两次测试，并测量了车内噪音。首先，激励是由一组外部扬声器以声学方式引起的。在第二次测试中，主要是结构噪声是由车辆在粗辊上以稳定速度行驶引起的。对于两种类型的激励，可以看出温度的影响很小，表明制造变异性大于所进行的测试中温度引起的变异性。还观察到，不存在明显的外围车辆，即最多只有少数车辆在整个频谱上始终具有最低或最高的噪声水平。对于声学激励测试，测得的 1/3 倍频程降噪水平通常具有 5dB 左右的扩展，并且线性数据的归一化标准偏差通常为 0.1 或更高。关于线性数据的统计分布，对于较低的 1/3 倍频程频带，对数正态分布比高斯分布更适合，而在较高频率下则相反。对于整体线性水平的分布，高斯分布通常是最具代表性的。作为响应变异性的简单描述，这一系列的测量足以假设声学引起的机舱噪声最好由归一化标准偏差在 0.09 和 0.145 之间的高斯分布来描述。滚轮引起的噪声通常存在相当大的变异性，各个 1/3 倍频程水平通常变化 15dB 左右，归一化标准偏差在 0.2-0.35 范围内 或更多。这些水平受到轮辋和轮胎结构的强烈影响。对于名义上具有相同轮辋和轮胎的车辆，40-600 Hz 频率范围内 1/3 倍频程的归一化标准偏差约为 0.2。每个 1/3 倍频程频带中线性滚子引起的噪声水平的分布可以通过对数正态分布很好地描述，总体水平也是如此。作为响应变异性的简单描述，这一系列的测量足以假设滚轮引起的道路噪声最好由归一化标准偏差为 0.2 左右的对数正态分布来描述，但这可能会受到轮胎和轮辋类型的显着影响，尤其是在较低频率下。 (C) 2008 Elsevier Ltd. 保留所有权利。
A statistical analysis of a series of measurements of the audio-frequency response of a large set of automotive vehicles is presented: a small hatchback model with both a three-door (411 vehicles) and five-door (403 vehicles) derivative and a mid-sized family five-door car (316 vehicles). The sets included vehicles of various specifications, engines, gearboxes, interior trim, wheels and tyres. The tests were performed in a hemianechoic chamber with the temperature and humidity recorded. Two tests were performed on each vehicle and the interior cabin noise measured. In the first, the excitation was acoustically induced by sets of external loudspeakers. In the second test, predominantly structure-borne noise was induced by running the vehicle at a steady speed on a rough roller.For both types of excitation, it is seen that the effects of temperature are small, indicating that manufacturing variability is larger than that due to temperature for the tests conducted. It is also observed that there are no significant outlying vehicles, i.e. there are at most only a few vehicles that consistently have the lowest or highest noise levels over the whole spectrum. For the acoustically excited tests, measured 1/3-octave noise reduction levels typically have a spread of 5dB or so and the normalised standard deviation of the linear data is typically 0.1 or higher. Regarding the statistical distribution of the linear data, a lognormal distribution is a somewhat better fit than a Gaussian distribution for lower 1/3-octave bands, while the reverse is true at higher frequencies. For the distribution of the overall linear levels, a Gaussian distribution is generally the most representative. As a simple description of the response variability, it is sufficient for this series of measurements to assume that the acoustically induced airborne cabin noise is best described by a Gaussian distribution with a normalised standard deviation between 0.09 and 0.145.There is generally considerable variability in the roller-induced noise, with individual 1/3-octave levels varying by typically 15dB or so and with the normalised standard deviation being in the range 0.2-0.35 or more. These levels are strongly affected by wheel rim and tyre constructions. For vehicles with nominally identical wheel rims and tyres, the normalised standard deviation for 1/3-octave levels in the frequency range 40-600 Hz is 0.2 or so. The distribution of the linear roller-induced noise level in each 1/3-octave frequency band is well described by a lognormal distribution as is the overall level. As a simple description of the response variability, it is sufficient for this series of measurements to assume that the roller-induced road noise is best described by a lognormal distribution with a normalised standard deviation of 0.2 or so, but that this can be significantly affected by the tyre and rim type, especially at lower frequencies. (C) 2008 Elsevier Ltd. All rights reserved.