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The evaluation of the sound quality of door-slamming has become one of the important issues in vehicle noise, vibration and harshness (NVH) analysis. For the sound quality evaluation of door-slamming, a new sound metric, named as sound metric based on critical band wavelet decomposition (SMCBWD), is developed. In the new sound metric, the sound signals of door-slamming are sampled and the signal component of the door-slamming sound which has the great influence on the quality of door-slamming is extracted by using the leaky integration method. The extracted signal component is then decomposed by wavelets based on the critical bands and the coefficients of wavelet decomposition are calculated. Based on the energy of the frequency weighted wavelet decomposition coefficients, the new sound metric, SMCBWD, is calculated. In order to verify the effectiveness of SMCBWD, the correlation coefficients between the new sound metric and the subjective sound quality performance value of door-slamming, as well as between the traditional sound metrics (loudness, sharpness) and the subjective sound quality performance value of door-slamming have been calculated, respectively. The results show that the new sound metric developed in this paper has the higher correlations with the subjective sound quality performance value when compared with the traditional sound metric of loudness and sharpness. Thus, SMCBWD can be used to evaluate the sound quality of door-slamming more accurately. 相似文献
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Development of a new sound metric for impact sound in a passenger car using the wavelet transform 总被引:1,自引:0,他引:1
Vehicles can experience impacts due to harsh road conditions. Contact with an uneven road surface causes vehicles to vibrate,
which generates a loud impact sound. The attenuation of such noise is important because car passengers may complain about
the impact noise. However, perfect removal of impact noise is not possible because most of it is caused by external conditions.
More research is needed on the objective attributes of impact noise; however, the problem of impact noise is not a simple
matter because impact noise is transient in nature and reaches a high level instantaneously. In this paper, a new objective
attribute of impact noise is designed using the wavelet transform, which is appropriate for analyzing nonstationary signals,
such as an impact signal. The usefulness of the new objective attribute, which is a sound metric, is examined by comparing
the mean subjective ratings for real impact noise in passenger cars. The new sound metric has better correlation with the
mean subjective rating than currently existing sound metrics. 相似文献
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针对某车车内噪声偏大的问题,对整车声学包进行了材料与声学性能方面的优化,并对优化后的零部件声学性能进行了对比测试,同时通过对整车车内声压级和语言清晰度进行了对比测试,测试结果表明,声压级降低了2dB(A)左右,语言清晰度提升了大约10%,达到了车内降噪的目的,提升了客户满意度。 相似文献
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《JSAE Review》1998,19(3):243-249
Reducing engine noise is one of the most important issues in lowering vehicle exterior noise. An engine under-cover is one effective measure for reducing engine noise. However, the size of the under-cover is limited by the need to ensure sufficient engine cooling performance. To solve this problem, a new sound insulation panel with ventilation holes was developed and applied to the engine under-cover. The panel accomplishes sound insulation by controlling the acoustic anti-resonance of sound waves transmitted through the ventilation holes. This paper describes guidelines for applying the panel to the engine under-cover from the viewpoints of acoustics and fluid dynamics. 相似文献
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为了减少道路行人与车辆碰撞,智能辅助驾驶系统采用行人检测与预警方式提醒驾驶人,从而降低人车碰撞风险.但在驾驶人意识模糊时,这种方式存在一定的不可靠性.以行人检测和碰撞风险预警为基础,基于车辆动力学模型提出一种智能车辆制动控制系统.在该系统中,通过视频传感器和图像的方向梯度直方图(HOG)特征,结合SVM识别算法,在大量图像样本量的前提下对行人进行目标识别与跟踪;运用碰撞风险识别与预警算法对最危险目标碰撞态势进行实时判断;采用车辆动力学模型开发的车速分级控制器实现车辆速度的自适应控制,实现不同风险状态下的车速智能控制.实车实验结果表明,基于该方法开发的系统能够快速并精准地检测行人,动态情况下行人识别准确率达到89%;基于风险预警判断进行车辆安全平稳的紧急制动,实现危险碰撞态势下的辅助操作,从而降低车辆与行人之间的碰撞概率. 相似文献
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为探究车辆右转过程中不同干预方式对驾驶人未规避行人行为的改善情况,设计听觉警示、触觉警示、形式惩罚、利益惩罚和道德惩罚5种干预方式,分为控制组、警示组和惩罚组,试验基于眼动仪和模拟驾驶仪展开。定义注视次数、注视点分布信息熵、平均注视时间、视线转移路径、区域关注概率和瞳孔面积6项指标表征驾驶人眼动特性,提取制动踏板深度比例、行车速度2项指标反映车辆运行状态。经方差分析确定各干预方式差异的显著性水平,从注视特性指标、扫视特性指标、瞳孔面积指标、驾驶人制动指标和机动车制动指标5个方面分析不同干预下驾驶人视觉及操纵响应特征,并收集被试反馈的追踪问卷。试验结果表明:不同干预方式对右转车辆未避让行人均有规范作用,各组干预效果由强到弱依次为利益惩罚、道德惩罚、形式惩罚、触觉警示和听觉警示。利益惩罚性主动干预效果优势显著,注视点分布信息熵最高为0.74,右侧平均注视次数为6次,平均注视时间增加至13.25 s,驾驶人对右侧注视概率增加至0.403,瞳孔面积明显增大,制动踏板深度比例维持在0.8,右转车速下降至20 km·h-1以下,谨慎驾驶程度和避让行人意识均有提升。一致性追踪问卷调查表明,结束试验时32%的驾驶人对利益惩罚印象深刻,驾驶人对其主观认可度高达83%,具有较强的推广性;该干预方式可帮助驾驶人规范驾驶行为,树立避让行人的安全驾驶意识。 相似文献
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本文中建立了GA-BP声品质预测模型,引入声品质贡献因子,以期通过传递路径分析更加直观地反映结构噪声传递路径对烦躁度的贡献情况和掩蔽效应对声品质的影响。采用两级优化方案,通过遗传算法确定与目标烦躁度值对应的目标传递函数,并进一步匹配悬置参数。结果表明,基于声品质贡献因子的发动机悬置优化方案可有效地改善车内声品质,降低结构路径对烦躁度的贡献量。 相似文献
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分析了电动汽车主要噪声源特性.举例介绍了数字化分析技术在电动汽车主要噪声源分析方面的应用研究,为分析电动汽车声品质特性提供了合理参考. 相似文献
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This study developed a methodology for evaluating the effectiveness of an integrated pedestrian protection system (IPPS) based on simulations. The proposed IPPS consists of active and passive vehicular systems for protecting pedestrians, including a pedestrian warning information system (PWIS), an active hood lift system (AHLS), and pedestrian airbag system (PAS). Two simulation methods were applied in the proposed methodology: a driving simulation and a finite element simulation. A driving simulator was used to obtain the change in collision speed, which is a key parameter for evaluating driving behavior when a PWIS is applied. In addition, a well-known simulator for finite element analysis, LSDYNA was used to simulate the impact of a pedestrian on a vehicle hood in a pedestrian-vehicle collision. The head injury criterion (HIC), which is an outcome of LS-DYNA simulations, is a major parameter for evaluating passive safety systems. The probability of pedestrian fatalities by collision speeds and HICs were estimated to quantify the safety benefits of an IPPS based on the statistical analyses. The results showed that an IPPS is capable of reducing pedestrian fatalities by approximately 90 % associated with jaywalking in the midblock and walking on the roadside. The findings of this study can be used to boost the development of various vehicular technologies for pedestrians. The results can be effectively used for policy making and deriving legislative requirements associated with advanced vehicular technologies for enhancing pedestrian safety. 相似文献
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驾驶室隔声漏声的声压法测量 总被引:1,自引:1,他引:1
为了控制车内噪声,研究驾驶室的隔声效果则是必不可少的环节。本文介绍一种简单可行的评价驾驶室隔声漏声的测量方法,并结合实际给出了声压法在驾驶室隔声漏声测量中的应用实例。在没有声学试验室的情况下,该试验方法不失为一项行之有效的方法。 相似文献
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《JSAE Review》1994,15(4):323-327
Conventionally, sound insulation materials have been applied to control interior noise above 500 Hz, and damping materials to control interior noise below 500 Hz. In this paper, the acoustical materials for vehicle panels, which consists of damping materials and sound insulation materials, are investigated by using a two-degrees-of-freedom system.The investigation shows that sound insulation materials can become effective to reducing interior noise below 500 Hz byducin their stiffness. This stiffness depends on not only the spring of the material itself but also on the pneumatic spring which is determined by air-flow resistance.This paper concludes with applications of techniquws to reduce interior noise below 500 Hz by improving sound insulation materials. 相似文献
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载货汽车车内噪声的控制 总被引:2,自引:0,他引:2
介绍了汽车车内噪声的评价指标和CA1091K2L2型汽车噪声控制的研究成果。车内噪声的控制,应首先考虑抑制发动机的辐射噪声。在驾驶室密封好的前题下,应对透声严重的驾驶室围板和底板采取隔声措施,使车内噪声降到最低程度,然后再考虑吸声材料的使用以及避免驾驶室空腔共振的措施。 相似文献
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