基于心理声学与声强法的汽车怠速异常噪声源识别

针对一样车开发阶段怠速工况出现的怠速车内异常噪声(简称异响),基于心理声学的分析方法对此异响进行声品质的客观量评价,定量地反映了正常噪声与异常噪声的主观感受差别;运用频谱分析技术初步确定怠速异响噪声的主要频谱范围在200~400 Hz;对异常噪声在200~400 Hz进行衰减滤波并进行声学回放与听觉比较,进一步验证了怠速异响的频率范围;采用声强测试得出发动机舱内声场分布,快速准确地确定了发动机正时轮系是引起怠速异响的主要来源,通过控制发动机悬置动刚度能够有效消除怠速异响。

Idle Abnormal Interior Noise Source Identification Based on Psychoacoustic Analysis and Sound Intensity Measurement

For an idle interior abnormal noise during vehicle prototype phase, sound quality evaluation was implemented based on psychoacoustic analysis approach, which indicated the subjective difference between normal noise and abnormal noise in quantitative objectively to some extent. The main idle abnormal noise source spectrum range was initially identified from 200Hz to 400Hz using spectral analysis method. The acquisition abnormal noise data were filtered in range of 200Hz to 400Hz, and the filtered noise playback was compared with normal noise, which further verified the idle abnormal noise frequency range previously described. The engine compartment sound field distribution was obtained using sound intensity measurement. The analysis results rapidly and accurately showed that the engine timing pulley system was the main source which caused idle abnormal noise. The idle abnormal noise can be effectively eliminated by controlling engine mount dynamic stiffness.