福特NVH培训1

VehicleNVHAwareness1.2IntroductiontoNVH11.2IntroductiontoNVHNVH介绍BenBachrach/JimSwayzeVehicleNVHAwareness1.2IntroductiontoNVH2Outline概要Introduction介绍Vibration/AcousticsFundamentals振动/声学的基本原理。HumanresponsetoVibrationandNoise人类对振动和噪声的反应。SoundQualityEngineering噪声品质工程。StandardNVHApproach标准的NVH方式。NVHTrade-offswithOtherAttributesNVH和其他属性的协调。VehicleNVHAwareness1.2IntroductiontoNVH3WhatisNVH?NVH是什么呢？Anaudibleortactiledisturbancewhichaffectscustomers.一种听得到的、看得到的，能影响消费者的因素。-Noise,Vibration,Harshness噪声，振动，不舒适性●Feel感觉●Hear听觉●See视觉VehicleNVHAwareness1.2IntroductiontoNVH4SystemEngineeringApproach系统工程方法★NVHisavehiclelevelattributeNVH是整车的性能。★Inputdefinedbyoperatingconditions.输入决定于操作环境。★Outputsdefinedbycustomersandregulatoryrequirements。输出决定于消费者和规定的要求。★Systempartitioning系统划分-Manageableelements-可以管理的-Non-unique-普遍的Inputs输入Process处理Outputs输出VehicleNVHAwareness1.2IntroductiontoNVH5SystemPartitionbysource通过来源来划分系统RoadNVH道路NVHWindNVH风的NVHPowertrainNVH动力系NVH-Climatecontrolsystem控制系统-Wipers擦拭系统-Seatmotors固定的发动机-Switches开关Vehiclecomponents车辆的构成VehicleNVHAwareness1.2IntroductiontoNVH6Physics物理学TransferbetweenPotentialandkineticenergy势能和动能的转换。Idealelements理想的原理-Mass-storeskineticenergy质量-储存动能-stiffness-storespotentialenergy刚性-储存势能-Damping-dissipatesenergy阻尼-衰减能量Waves波-Pressurewavesinfluid(air,oil)在流体中的压力波(空气,油)-stresswavesinsolids在固体中的压力波Spring弹性Mass质量Damper阻尼器VehicleNVHAwareness1.2IntroductiontoNVH7TimeandFrequencyDomains时域和频域TimeDomain时域Amplitude振幅FrequencyComponents频率组成FrequencyDomain频域Amplitude振幅Amplitude振幅VehicleNVHAwareness1.2IntroductiontoNVH8FrequencyAnalysis频率分析Oscillatingmotioncanbedescribedasasumofsinusoidalmotions(FourierSeries)振荡运动能被描述为一个正弦曲线的运动（傅里叶级数）Eachsinewaveisdefineby:每个正弦波都被下列方面详细说明：-Amplitude振幅-Frequency频率-Phase相位At0TVehicleNVHAwareness1.2IntroductiontoNVH9WhyUseFrequency为什么利用频率Theresponseofmechanicalsystemsmosteasilyunderstoodandanalysisinfrequencydomain原因是其容易被理解Humanresponsetonoiseandvibrationstronglyinfluencedbyfrequency人类是通过频率来表示噪声和震动的强度的。NVHproblemsusuallyoccuratspecificfrequencyranged-allowseasierclassificationanddiagnosis.NVH问题通常出现特定的范围--比较容易分类和诊断。VehicleNVHAwareness1.2IntroductiontoNVH10FrequencyRanges频率范围Vibration振动-wholebody整个车身●Vehiclesdynamics0.1-20Hz车辆动态为0.1-20赫兹●Shake10-30Hz颤抖时为10-30赫兹●Fingers10-40Hz-visual可视的●2-20HzVehicleNVHAwareness1.2IntroductiontoNVH11FrequencyRanges频率范围Sound噪声-Structureborne结构噪声●20-50Hz-Airborne空气传播澡声●250-5000HzVehicleNVHAwareness1.2IntroductiontoNVH12Spectrum频谱Amplitudevs.Frequency振幅和频率AlternativefrequencyResolutions频率分类方案●NarrowBans-1Hz狭窄部分-1赫兹●Octaves-fc=16,31.5,63,125,250,500,1000,2000●1/3Octaves-f1=21/3fc,f2=22/3fc,f3=2fcVehicleNVHAwareness1.2IntroductiontoNVH13OtherTerms其它条件criticalBands关键的频段-frequencybandsbasedonresponseofhumanear频段基于人类耳朵的反映。-approximatelyequal1/3Octave近似于等于1/3倍频程。Harmonics–Integermultiplesoffundamentalfrequency(1stHarmonic)inasignal3rdHarmonicfrequency=3×fundamental和声学—在一个信号里第3个和声的频率是基本频率的3倍。Orders–multiplesofarotationalspeedfiringfrequencyofa6cylinderengineisthirdorder.阶—六缸发动机的角速度频率是第3阶VehicleNVHAwareness1.2IntroductiontoNVH14WaterfallPlotsandOrderAnalysisVehicleNVHAwareness1.2IntroductiontoNVH15EngineeringMeasuresofVibration衡量振动的方法Acceleration加速度Velocity速度Displacement位移VehicleNVHAwareness1.2IntroductiontoNVH16WeightingSchemes权衡方案Vibrationdoesvalue振动值ISOexposurelimits国标的允许限度Constantvelocity等速度周转率VehicleNVHAwareness1.2IntroductiontoNVH17EngineeringMeasureofSound噪声的衡量方法Soundpressure噪声的压力Soundintensity噪声的强度Soundpower噪声的能量VehicleNVHAwareness1.2IntroductiontoNVH18DecibelScale分贝L[dB]=20*LOG10(A/Aref)Forsoundpressurelevel噪声的压力标准Aref=20×10-6PaEffectofaddingtwosignals,LAandLBtogiveLC加入两个信号LA和LB对LC的影响。LALBLC100010010080100.810090102.4100100106100110112.4100120120.8VehicleNVHAwareness1.2IntroductiontoNVH19WeightingSchemes权衡方案dBA,dBB调整分贝，检波器反偏压。Phons,sones,speechintelligibility,roughness音响的强度单位，宋，语音可识度，不调和。Filtersappliedtosoundsignals滤清器应用到音信号。Toprovidemetricsthatcorrelatewithhumanperceptions提出了与人类相关的音律学。-frequencydependence频率相依性-masking屏蔽VehicleNVHAwareness1.2IntroductiontoNVH20SPLWeightingSPL权衡VehicleNVHAwareness1.2IntroductiontoNVH21SPLWeightingSPL权衡VehicleNVHAwareness1.2IntroductiontoNVH22SoundQualityEngineering音质工程DefineNVHquality定义NVH音质Customersurveys消费者调查Evaluationtrips评估过程Listeningclinics临床测试-Pairedcomparison对比对照-semanticdifference差异Vibrationsimulators振动模拟训练装置Warrantydate授权日期VehicleNVHAwareness1.2IntroductiontoNVH23StandardNVHApproach标准NVH方式Source/path/receiver来源/路径/接受装置Forces力量Structuralresponses结构的响应Modalanalysis模式分析NVHtreatmentsNVH诊治VehicleNVHAwareness1.2IntroductiontoNVH24Source/Path/Receiver来源/路径/接受装置Source-causesdisturbance来源-干扰因素Path-mayisolateoramplifydisturbance路径-隔离或者增强干扰Receiver-respondstodisturbance接受-干扰响应NVHstrategyNVH策略Source来源times×PathSensitivity路径敏感=Response响音VehicleNVHAwareness1.2IntroductiontoNVH25Sources来源Repetitiveevents反复事件-Rotatingequipment旋转器材●Powertrain/wheel/tires动力系/轮子/轮胎Randomevents随机事件-Road/windnoise道路/风的噪声Impacts冲击-Discreteroadevents不连续的道路事件-Transmissionshifts变速箱换档VehicleNVH