车用柴油机辐射噪声已成为环境污染噪声的重要组成部分,开展车用柴油机噪声品质的预测与评估研究具有重要的理论与实际意义。以Q型车用柴油机为例,研究其在变负荷及转速工况下表面辐射噪声品质情况,为进一步提高整机声品质,开展柴油机结构声学设计奠定了理论基础。研究国内外车用柴油机客观评价特征,选取物理声学特征峭度、冲击量特性以及心理声学特征响度、尖锐度、粗糙度和波动强度参量来描述辐射噪声的客观特征;针对柴油机噪声特点,采用分类对偶比较法开展以专业听审人群为目标的综合满意度评价研究;应用多层感知器神经网络算法建立起该车用柴油机声品质预测模型。研究表明,车用柴油机噪声品质预测模型能够准确地反映客观评价参量与主观满意度之间的非线性映射关系。
Diesel engine noise has become an important component of the environmental noises,the research on establishment and evaluation of diesel engine noise is of importance in theory and practice.The Q diesel engine is taken as a sample;the sound quality of the radiated noise varied with loads/speeds is studied so as to improve the radiated noise quality and establish the theoretical foundation for the structure acoustical design.On the basis of studying the objective evaluation of diesel engine radiated noise at home and abroad,the physical acoustics parameters kurtosis,impulsiveness characters and psychoacoustics parameters consisting of loudness,sharpness,roughness and fluctuation strength are chosen to describe the objective characteristics of the diesel engine noise;Considering the characteristics of the diesel engine noise,the experienced listeners and the classified-paired comparison are applied in the subjective evaluation;the prediction model of noise quality is established by the multilayer perceptron neural networks.The prediction model for diesel engine noise quality can reflect the non-linear relationship between objective characteristics and subjection evaluation results accurately.