不同速度的各类型机动车噪声频率特性

通过采集不同速度的各类型机动车噪声数据，对噪声的频谱和不同频段的能量比率进行分析和比较，得到不同速度下的各类型机动车噪声的频率特性。结果表明，大部分机动车噪声能量主要集中在400 Hz到2.5 kHz之间，其中小型车噪声能量以1 kHz到2.5 kHz的频段为主，大型车噪声能量主要在400 Hz到2.5 kHz均匀分布，中型车噪声能量分布特征介乎两者之间，而公交车噪声能量则以10 Hz到315 Hz的低频段为主；随着速度的增加，中、小型车噪声能量分布频段更为集中，大型车噪声频率分布与速度关系不明显，公交车低频段噪声能量比率有所提高。

Frequency Characteristics of Noises of Various Types of Vehicles in Different Speeds

This paper describes an investigation about the frequency characteristics of the various types of vehicles in different speed. The noise samples were recorded to analyze the spectrum and the energy ratio of different frequency bands. The results showed that most of the vehicle noise energy was mainly located between 400Hz and 2.5kHz. The noise energy distribution of small cars was almost from 1kHz to 2.5kHz, the noise energy of large cars was evenly distributed from 400Hz to 2.5kHz and the noise energy distribution of middle cars was in between. Most of buses noise energy was located in low-frequency band from 10Hz to 315Hz. As the speed increased, the energy distribution of small cars and middle cars was more concentrated, the noise frequency of large cars has no significant relationship with speed and the ratio of bus noise energy in low-frequency band was increased.