数值仿真生成的汽车后空调气动噪声预测及评价

为解决需要项目开发后期样车完成后才能进行整车空调气动噪声性能测试及评价的滞后性问题,针对某SUV整车后空调高档范围工作产生的气动噪声,提出了一种基于空调整车计算流体动力学和FW-H声类比方程的气动噪声仿真计算分析和神经网络的主观评价预测方法。首先采用计算流体动力学和FW-H声类比相结合的方法仿真计算和验证后空调高档运行时车内产生的气动噪声特性;然后将仿真得到的时域气动噪声样本转化成声频格式,并开发GUI程序界面进行噪声样本主观评价和客观参数计算;最后建立基于遗传算法优化的主客观映射神经网络预测模型以实现车内后空调气动噪声性能的预测评价。仿真计算及预测评价结果表明：该方法计算的气动噪声仿真误差在10%以内,主观预测误差在0.5分以内,可有效指导汽车空调气动噪声性能的前瞻性预测开发。     

混合动力车型燃油箱晃荡声的时变响度评价方法与降噪应用

随着市场对汽车舒适性要求的提高,燃油箱油液晃动噪声问题越来越被重视。尤其是对于混合动力乘用车型,由于缺少发动机怠速噪声的掩蔽效应,更容易引起市场用户对燃油箱晃荡声的抱怨。本文以某搭载BSG混合动力SUV(Sports Utility Vehicle)车型的燃油箱晃荡声问题为案例,系统性地进行了整车测试分析与路径排查工作,通过对比分析声压级与响度指标方法的差异,说明了采用时变响度声品质指标能够更准确地反映出车内人耳对晃荡声的主观评价感受。本文主要通过“结构声”传递路径的优化,降低了油箱晃动激励到车内的传递,显著改善了车内的油液晃荡声问题,这为提升燃油系统NVH性能集成开发的能力,有着较重要的工程参考价值。     

采用响应面回归的汽车多属性声品质预测方法*

单一主观评价分数无法准确描述人耳对声品质的多属性偏好特征。该文在多属性声品质试验数据的基础上,以愉悦度、平顺度和驾驶乐趣的主观评价分数为因变量,通过相关分析筛选出响度、尖锐度和A计权声压级3个主要自变量,引入响应面回归方法,分别建立因变量与自变量之间的预测模型,通过与多元线性模型和BP神经网络模型对比验证了精度。最后,建立多属性主观评价分数之间的量化映射模型。该研究可为多属性汽车声品质的优化控制提供参考。     

基于非度量多维尺度分析的噪声声品质主观评价研究

以等响处理后双耳记录的车内噪声为例,针对非度量多维尺度分析(NMDS)是否适用于研究一致性较强的噪声声品质主观评价这一疑问进行研究。研究发现,按照评价者之间正负相关性分类处理的方法,对于运用NMDS揭示了一致性较强的复杂车内噪声声品质潜在的主观感知结构起着重要作用。采用该方法可以揭示出:车内噪声的偏好性可以作为主观感知相似性主要子维度的表示;评价者分类处理之后,两类评价者对于车内噪声的偏好性均可采用一个维度表示,并可直接采用成对比较法的直接排序法获得;一类评价者的偏好性与低沉度成正比,而另一类评价者与低沉度成反比。     

语音清晰度和平均混响时间在车内声学中的应用

乘用车的车内声学性能直接影响人的主观感受,但仅靠主观评价来判定是不够的;必须通过引入有力的客观参量来刻画车内听觉的舒适度效果。而如何来设计车内噪声试验方案来诊断和改善声学水平则成了一个重要的环节。在乘用车车内噪声品质的开发过程中,综合应用语音清晰度和平均混响时间两个指标对车内吸声性能进行了对比分析。通过对实车主观评价和客观测试,讨论了语音清晰度、车内平均混响时间、吸声系数和声压衰减斜率的概念及相互关系,从而确定了高速道路行驶工况下的语音清晰度主要取决于车内吸声材料的性能。提出了将车内相关部位进行材料吸声改进作为改善语音清晰度的主要措施之一。     

空调压缩机噪声测试及其声品质客观参量分析*

针对空调压缩机辐射声场的不同场点噪声声品质的差异,采用心理学声品质参量即响度、尖锐度、总感觉噪度,对压缩机辐射声场的不同场点噪声进行声品质客观参量分析,研究压缩机场点噪声声品质客观参量值变化规律。通过特征响度研究各场点噪声响度在频域的分布,并得出压缩机各场点噪声特征响度峰值所在噪声频带。实验结果表明,对于处在压缩机不同方向上的场点,其噪声声品质客观参量值存在明显差异,但其噪声特征响度峰值却处在相同的噪声频带。研究工作为压缩机全方向降噪提供参考依据也为研究压缩机的噪声声品质探索了一种新思路。     

声品质主观评价的分组成对比较法研究

声品质主观评价实验中,大样本量的成对比较法评价实验由于评价时间随样本量的平方增长而变得难以实现,为此提出了可有效减少评价工作量并使得实验易于实现的分组成对比较法。将总体评价样本分成具有相互联系的n个样本组分别进行主观评价,通过各组间的关联样本将各组的评价结果进行反演构建,得到总体样本的评价结果,进而分析其声品质特征。以车内噪声为例,介绍了分组成对比较法的实现方法,并与传统成对比较法以及语义细分法实验结果进行了对比分析,两者结果获得较好的一致性,证明了分组成对比较主观评价实验方法的有效性。     

地铁沿线建筑内噪声多维度感受影响机制

随着城市铁路系统的快速发展,铁路沿线建筑内人群对地铁运行产生噪声的抱怨逐渐增多,为控制室内地铁噪声对人群所产生的负面影响,有必要对地铁噪声产生的多维度负面情绪进行评估。采集了79名受试者对建筑内地铁噪声的多维度负面感受(压抑感,不舒适度和不满意度),基于偏最小二乘法分析了主客观影响因素对多维度负面感受的作用机制,并比较了多维度负面感受在反映地铁噪声影响上的差异。结果表明,多维度负面感受主要取决于主观响度和声学参数,活动干扰度、地铁噪声的敏感度、厌烦度和适应性的影响明显更弱;3个多维度负面感受中,相比于压抑感,不舒适度和不满意度受主观响度的影响轻微更显著,在相同的主观响度感受下,不满意度等级最高。 该文可以为地铁沿线建筑物内噪声负面感受的评价和改善提供参考。     

高速列车噪声与速度关系变化分析

随着高速列车运行速度的提升,高速列车内部噪声过高的问题日益突出,识别高速列车在高速运行时主要噪声来源对减振降噪非常重要。本文针对我国高速列车CRH380B型车,在多工况的实车运行状态下进行噪声振动测试研究,并利用速度指数拟合进行计算。得到了我国CRH380B型高速列车不同的噪声随速度指数变化的规律和车内车外的过渡速度区。该结果能够对高速列车噪声来源识别提供参考,为高速列车的车厢内部低噪声设计提供依据。     

高速列车车内压力波动模糊控制研究

高速列车在通过隧道或两车交会时,列车表面会产生很大的气压波动,此压力波动通过车体缝隙和换气风机、风道传入车内,引起车内空气压力较大波动,造成乘客耳鸣、耳痛等症状,影响乘坐舒适性;为了抑制高速列车车内压力波动,根据某型高速列车换气风机特性曲线与车体等效泄露关系,建立了换气风机频率可变的车内外空气压力传递数学模型;采用模糊控制策略,以车内压力、车内压力变化率为控制输入,对高速列车换气系统中的新风风机、废排风机运行频率进行调节;仿真结果表明:该控制方式能够提高现有换气系统对车内空气压力波动的抑制能力,提高乘坐舒适性。      

使用者的社会因素对地下商业街主观响度和声舒适度影响的调查研究

前人研究表明主观响度和声舒适度由实际环境中的众多因素决定,而不是仅受声压级的影响。本文在对地下商业街声场和声源特性进行调查与分析的基础上,针对使用者的社会因素对主观响度和声舒适度的影响,在哈尔滨的几个典型地下商业街进行了大量问卷调查,并运用相关统计方法对结果进行了分析。研究表明,收入和职业与主观响度存在相关性,相关系数在0.1～0.4之间,学历、收入和职业与主观声舒适度亦存在相关性,相关系数在0.1～0.6之间。虽然性别对主观响度和主观声舒适度无显著性影响,但是女性对这两者的主观感觉评分范围比男性宽。年龄段与主观响度和声舒适度的相关性不显著,但是不同地下商业街有的年龄段对主观响度和声舒适度的感受有区别。职业对于主观声舒适度的影响的本质是源于收入和学历对于主观声舒适度的作用,并且收入对于主观声舒适度的影响要大于学历的影响。这些结果可以增加对地下商业街声景的了解,并且为建立地下商业街声景预测模型提供了基础。     

Reliability improvement of a sound quality index for a vehicle HVAC system using a regression and neural network model

The reduction of vehicle interior noise has long been the main interest of noise and vibration harshness (NVH) engineers. A driver’s perception of vehicle noise is largely affected by psychoacoustic noise characteristics and SPL. Among the various types of vehicle interior noise, the sound of the heating, ventilation, and air conditioning (HVAC) systems is a source of distraction for drivers. HVAC noise is not as loud as the overall noise level; however, it affects a driver’s subjective perception and may lead to feelings of nervousness or annoyance. Therefore, vehicle engineers work not only to reduce noise, but also to improve sound quality. In this paper, HVAC noise samples were taken from many types of vehicles. Objective and subjective sound quality (SQ) evaluations were obtained, simple and multiple regression models were generated, and these were used with the Semantic Differential Method (SDM) to determine what characteristics trigger a “pleasant” response from listeners. The regression analysis produced diagnostic statistics and regression estimates. In addition, neural network (NN) models were created using three objective numerical inputs (loudness, sharpness, and roughness) of the SQ metrics and one subjective output (“pleasant”). The NN model was used primarily because human perceptions are very complex and often hard to estimate. The estimation models were compared via correlations between SQ output indices and hearing test results. Results demonstrated that the NN model is most highly correlated with SQ indices, which led to determination of suggested methods for SQ metrics prediction.     

卷积神经网络用于近红外光谱预测土壤含水率

近红外光谱分析技术在土壤含水率预测方面具有独特的优势，是一种便捷且有效的方法。卷积神经网络作为高性能的深度学习模型，能够从复杂光谱数据中自主提取有效特征结构进行学习，与传统的浅层学习模型相比具有更强的模型表达能力。将卷积神经网络用于近红外光谱预测土壤含水率，并提出了有效的卷积神经网络光谱回归建模方法，简化了光谱数据的预处理要求，且具有更高的光谱预测精度。首先对不同含水率下土壤样品的光谱反射率数据进行简单的预处理，通过主成分分析减少光谱数据量，并将处理后的光谱数据变换为二维光谱信息矩阵，以适应卷积神经网络特殊的学习结构。然后基于卷积神经网络算法，设置双层卷积和池化结构逐层提取光谱数据的内部特征信息，并采用局部连接和权值共享减少网络参数、提高泛化性能。通过试验优化网络结构和各项参数，最终获得针对土壤光谱数据的卷积神经网络土壤含水率预测模型，并与传统的BP，PLSR和LSSVM模型进行对比实验。结果表明在训练样本达到一定数量时，卷积神经网络的预测精度和回归拟合度均高于三种传统模型。在少量训练样本参与建模的情况下，模型预测表现高于BP神经网络，但略低于PLSR和LSSVM模型。随着参与训练样本量的增加，卷积神经网络的预测精度和回归拟合度也随之稳定提升，达到并显著优于传统模型水平。因此，卷积神经网络能够利用近红外光谱数据对土壤含水率做出有效预测，且在较多样本参与建模时取得更好效果。     

Sound quality of low-frequency and car engine noises after active noise control

The ability of active noise control (ANC) systems to achieve a more pleasant sound has been evaluated by means of sound quality analysis of a real multi-channel active noise controller. Recordings of real car engine noises had been carried out using a HeadacousticsTM binaural head simulator seated in a typical car seat, and these signals together with synthesized noise have been actively controlled in an enclosed room.The sound quality study has focused on the estimation of noise quality changes through the evaluation of the sense of comfort. Two methods have been developed: firstly, a predictive method based on psychoacoustic parameters (loudness, roughness, tonality and sharpness); and secondly, a subjective method using a jury test. Both results have been related to the spectral characteristics of the sounds before and after active control.It can be concluded from both analyses that ANC positively affects acoustic comfort. The engine noise mathematical comfort predictor is based on loudness and roughness (two psychoacoustic parameters directly influenced by ANC), and has satisfactorily predicted the improvements in the pleasantness of the sounds. As far as the subjective evaluation method is concerned, the jury test has showed that acoustic comfort is, in most cases, directly related to the sense of quietness. However, ANC has also been assessed negatively by the jury in the cases that it was unable to reduce the loudness, perhaps because of the low amplitudes of the original sounds.Finally, from what has been shown, it can be said that the subjective improvements strongly depends on the attenuation level achieved by the ANC system operation, as well as the spectral characteristics of the sounds before and after control.     

基于深度神经网络的镜片佩戴舒适度研究

为了客观评价镜片佩戴舒适度,研究设计眼动实验,利用眼动仪采集并分析眼动数据,提出"眼睑间距变动百分比"作为镜片佩戴舒适度评价指标之一,再结合其他传统眼动指标,设计了一种基于深度神经网络的镜片佩戴舒适度评价模型。结果表明提出的眼睑间距变动百分比指标用于评价镜片佩戴舒适度具有良好的效果,最终构建的深度神经网络模型预测准确率较高,具有较好的泛化能力。研究突破了传统配镜过程主要依靠患者主观评价的限制,可以有效帮助视光医生和配镜师调整镜片设计方案。     

基于混合神经网络和注意力机制的混沌时间序列预测

为提高混沌时间序列的预测精度,提出一种基于混合神经网络和注意力机制的预测模型(Att-CNNLSTM),首先对混沌时间序列进行相空间重构和数据归一化,然后利用卷积神经网络(CNN)对时间序列的重构相空间进行空间特征提取,再将CNN提取的特征和原时间序列组合,用长短期记忆网络(LSTM)根据空间特征提取时间特征,最后通过注意力机制捕获时间序列的关键时空特征,给出最终预测结果.将该模型对Logistic,Lorenz和太阳黑子混沌时间序列进行预测实验,并与未引入注意力机制的CNN-LSTM模型、单一的CNN和LSTM网络模型、以及传统的机器学习算法最小二乘支持向量机(LSSVM)的预测性能进行比较.实验结果显示本文提出的预测模型预测误差低于其他模型,预测精度更高.     

Sound quality evaluation of the booming sensation for passenger cars

Automotive booming noise due to powertrain occurs when pure or narrow band tones related to the firing frequency of engine and its harmonics excite the passenger cavity, which entails a prominent increase of sound intensity. The booming sensation has been considered as very important to the acoustic comfort of passengers. In this study, a sound quality index which can objectively evaluate the booming sensation was derived. Because of the tonal nature of powertrain booming noise, subjective pitch was employed to find only aurally relevant tonal components which influence booming sensation as well as loudness. Using the empirical data and the frequency difference limen for just-noticeable change of booming sensation obtained from the listening test, an existing pitch extraction algorithm could be modified. The modified pitch model was applied to the interior noises of accelerating passenger cars together with a loudness analysis for representing the objective features of booming feeling. Subjective tests using the magnitude estimation method were conducted to evaluate the degree of booming sensation. Finally, booming strength was proposed for quantifying the booming sensation, which was validated by subjective results. The correlation coefficient between the derived booming strength and the degree of booming sensation obtained by the subjective test was 0.926.     

大型综合医院室外声景观评价影响因素分析 ——以长沙市中心医院为例*

本文通过定点实测结合问卷调查的方式,对长沙市中心医院室外声景观进行调查评价并通过主成分分析法、多因素方差法等对评价结果进行分析,探究影响评价声景观评价结果的因素。结果表明：(1)调查时间、调查地点的声音类型、受访者身份、室外停留时间和来往目的等因素会对声景观评价结果产生影响,而受访者的年龄、性别、职业等社会因素则不会产生影响；(2)声景观整体满意度一般,医院员工和病患较其他人员、工作日较休息日的改进意愿更加强烈,语义词调查结果整体偏向贬义负值,病患和建筑出入口区域的评价结果更偏向主观消极感强烈的词汇；(3)主观响度评价结果为机械声＞社会活动声＞自然声,舒适度和好感度与之相反。受访身份对主观响度评价结果影响不大,但会对舒适度和好感度的评价结果产生影响,病患对警铃声和医疗设备声的好感度和舒适度明显更低；(4)医院停留时间、室外停留时间和目的等行为因素与声景观评价结果呈现较强的相关性。     

Acoustic comfort in large dining spaces

This study carried out a questionnaire field investigation in two typical large dining spaces. The results suggest that the acoustic comfort of diners has an influence on the comfort evaluation of the overall dining environment, and background noise is an important factor affecting the acoustic comfort evaluation of diners. The role of various individual sound sources in background noise has been investigated, considering general background music, speech sound, activity sound, and mechanical noise, and it has been revealed that background music, other diners’ speech sound and tableware’s impact sound has a dominant impact on the acoustic comfort evaluation of diners. Compared with the existence of background music in background noise, diners’ acoustic comfort evaluation is higher than that without background music. The loudness, articulation, noise level and preference degree of various individual sound sources are factors which affect diners’ acoustic comfort evaluation on sound sources. In terms of demographic and social factors, gender and the frequency of dining out have a significant impact on diners’ acoustic comfort evaluation.     

Sound quality evaluation of vehicle suspension shock absorber rattling noise based on the Wigner–Ville distribution

In this paper, a new sound metric–Sound Metric based on the Wigner–Ville distribution (SMWVD) – was developed to investigate the relationship between subjective evaluations and vehicle suspension shock absorber rattling noise, which substantially affects passengers’ psychological and physiological perceptions. A complete vehicle road test was conducted to measure the interior shock absorber noises, which were subjectively evaluated by 20 jurors. Conventional psychoacoustic indices, i.e. loudness, sharpness, roughness and fluctuation strength, were used to calculate the correlation coefficients between the objective and subjective evaluations, and then, the results were compared with the performance of the SMWVD. The results show that conventional sound metrics have poor relationships with the subjective ratings, while the SMWVD displayed a high correlation of >0.9 between the objective evaluation and the subjective evaluation. These results indicate that the SMWVD can be used to estimate the rattling noise index of a suspension shock absorber without jury evaluation.