轿车NVH性能测试方法

TITLE: Vehicle NVH Test Procedure
轿车NVH性能测试方法
Vehicle Operation: (车辆操纵)
· Engine Idle (optional): In this condition, the engine would be idling in neutral and the microphones located inside of the vehicle would record the interior vehicle sound pressure level at different locations.
发动机怠速(可选项测试):
怠速条件下，变速器置于空档，传声器放在车内不同位置，测量
并记录不同位置的声压等级。

· 70 or 80 miles/H or other speed Cruise: In this condition, the vehicle is set to cruise at 70 or 80 miles per hour and the microphones located inside of the vehicle would record the interior vehicle sound pressure level at different locations.
车辆在时速70km或80km(或60~120kph)等6速度下:
匀速行驶中, 传声器放在车内不同位置，测量并记录不同位置的声压等级
o Operating Condition: 2 nd & 3 rd gear – Manual or
1 st /Low &
2 nd Gear – Auto
车辆操控条件：手动档稳定在2档或3档, 自动档稳定于一档
(低速)或2档
· Rough road (optional): In this test configuration, the vehicle runs over different asphalt textures to capture the road noise impact at the driver’s ear.
起伏路面/粗燥路条件(可选项测试)：
在此条件下，车辆在不同的质地的沥青路面上行驶，路面噪音对
车内噪音的影响需要被测量出来。

o Operating Condition: The operating condition could be set per OEM specification.
车辆操控条件：可按照OEM客户的测试标准执行 · Wide Open Throttle (WOT) Acceleration operation: In this condition, the vehicle operates at wide open
throttle. The engine tachometer in conjunction with the interior sound pressure level inside the vehicle should be recorded.
节气门全开加速(可选项测试)
车辆加速条件下, 连接发动机转速计，软件需记录车辆内部声压等级：
o Operating Condition: 2 nd & 3 rd gear – Manual or
1 st /Low &
2 nd Gear - Auto
车辆操控条件：手动档稳定在2档或3档, 自动档稳定于一档
(低速)或2档
Transducers: 传声器放置
A total of four to eight ICP microphones made by PC
B could
be placed inside of the vehicle at the following locations.
These microphones should be connected with the B&C cables to the end of the Prosig analyzer.
PCB/GRAS公司的四到八通道ICP传声器放置在以下位置，这些传声器必须通过B&C线缆和LMS声音分析仪连接.
Each channel of the analyzer should be set at 48 kHz. This would provide the sound pressure level information from 20Hz - 20 kHz. Later this information could provide an overall sound pressure level at any of the microphones listed above as a function of RPM(revolution per minute) or frequency. The time signal can be processed to narrow band frequency spectrum and later to 3rd octave band.
每个通道的频率需设定在24kHz，以便于能测量到在20Hz到2000Hz范围内的声压级信号。

之后，这些信号可以任何传声器在不同频率的RPM对总体声压级的贡献。

总体声压级信号可以被在更窄的频谱带甚至第三倍频带宽度内进行处理。

1. Driver’s ear outboard 驾驶员左耳
2. Passenger’s ear outboard副驾驶右耳
3. Rear seat upper, left outboard 后排座
位上左外侧
4. Rear seat upper, right outboard 后排座位
上右外侧
5. Engine tachometer 发动机转速计（需要连接）
Vehicle Preparation: 被测车辆准备
The test vehicle should be in a good operational condition and the fuel level and load condition should be identical from test to test. The following describes the steps for the vehicle test preparation:
被测车辆应处于正常的操作状态，燃油量级和道路状况在整个测试过程中应保持一致。

测试步骤描述如下：
1. First, place the microphones as listed above. A typical
microphone setup is provided in the following figure:
放置传声器在以上指定的位置。

典型的放置方位如图所示。

2. Connect all of the microphones and engine tachometer to
a LMS 16-channel analyzer.
连接所有的传声器和发动机转速计到噪声分析仪。

3. Calibrate all the microphones and record their
sensitivity in the analyzer.
校正传声器并在分析仪上记录每个传声器的灵敏度。

4. At this stage, the vehicle is ready to be tested with
the conditions described above.
在此阶段，车辆就处于准备就绪的被测状态。

5. Set the gain of the microphones according to the vehicle
Figure: The Microphone Location Configuration
传声器放置方位图
Vehicle Operation: 车辆操纵
This section describes how the vehicle should be driven.
车辆应按照以下方式操作行驶：
1. First the vehicle should be warmed and for every
condition, the data base file should be established in the analyzer.
首先，对于每种条件的测试，车辆应当被预热。

噪声分析仪这时也应当准备好数据库文件。

2. Be sure that the AC system is turned off during the
testing.
确定AC空调系统的整个测试过程中处于关闭状态。

3. There should not be any movement or disturbance inside
of the vehicle.
测试过程中，车内不能有任何的运动和干扰。

4. At each condition, the analyzer should be started and
collected at 10-30 second intervals. This should be repeated at least 3 to 5 times.
在每种测试条件下，分析仪每次开启采集信号应当有10到30秒间隔，并且需要3到5次重复采集。

Data Processing:数据处理
无论是怠速状态，行驶状态或加速度状态的数据采集，需要经过信号处理软件包进行处理。

声音信号可被转换为不同频域下的高分辨率信
号，最终转换到三分之一倍频程。

分析每次循环测试的平均值，找出不同循环之间的偏差以及不同操作的偏差。

本测试的目标是测量每个传声器位置处（驾驶员处或副驾驶处等）的在不同频率范围的总体声压等级。