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GB/T 40578-2021 PDF in English


GB/T 40578-2021 (GB/T40578-2021, GBT 40578-2021, GBT40578-2021)
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GB/T 40578-2021: PDF in English (GBT 40578-2021)

GB/T 40578-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 43.040
CCS T 34
Measurement methods for noise emitted by light-duty
vehicles in multiple driving mode conditions
(ECE Regulation No.51, Revision 3, 2016, Uniform provisions
concerning the approval of motor vehicles having at least four wheels
with regard to their sound emissions, NEQ)
ISSUED ON: OCTOBER 11, 2021
IMPLEMENTED ON: MAY 01, 2022
Issued by: State Administration for Market Regulation;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative references ... 5 
3 Terms and definitions ... 6 
4 Measurement instruments ... 7 
5 Measurement conditions ... 8 
6 Noise test ... 10 
Annex A (informative) Recording sheet for noise measurement emitted by light-
duty vehicles in multiple driving mode conditions ... 14 
Bibliography ... 17 
Measurement methods for noise emitted by light-duty
vehicles in multiple driving mode conditions
1 Scope
This Standard specifies measuring instruments, measurement conditions, test
requirements for measurement methods for noise emitted by light-duty vehicles
in multiple driving mode conditions.
This Standard is applicable to measurement of noise emitted by M1 category,
M2 category and N1 category vehicles with the maximum design total mass not
exceeding 3500kg in multiple driving mode conditions.
2 Normative references
The following referenced documents are indispensable for the application of
this document. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any
amendments) applies.
GB/T 3730.2, Road vehicle. Masses. Vocabulary and codes
GB/T 3785.1, Electroacoustics - Sound level meters - Part 1: Specifications
GB/T 6326, Tyre terms and definitions
GB/T 12534, Motor vehicles. General rules of road test method
GB/T 15089, Classification of power-driven vehicles and trailers
GB/T 15173, Electroacoustics - Sound calibrators
GB/T 19596, Terminology of electric vehicles
GB/T 38146.1, China automotive test cycle - Part 1: Light-duty vehicles
GB/T 40625-2021, Indoor measurement methods for noise emitted by
accelerating motor vehicles
ISO 10844, Acoustics - Specification of test tracks for measuring noise
emitted by road vehicles and their tyres
3 Terms and definitions
For the purposes of this document, the terms and definitions defined in GB/T
3730.2, GB/T 6326, GB/T 15089, GB/T 19596, GB/T 38146 as well as the
followings apply.
3.1 test mass of vehicle; mt
the mass that the curb weight of the whole vehicle plus the weight of 75kg
3.2 total power of vehicle; Pn
the total power of the power source directly involved in the driving of the vehicle
NOTE: The maximum net power of an automobile engine measured according to GB/T
17692, in kilowatts (kW). In electric vehicles, the total power of pure electric vehicles refers
to the sum of the peak power of all drive motors measured according to GB/T 18488.2. The
total power of a hybrid electric vehicle refers to the sum of the maximum net power of the
engine measured according to GB/T 17692 and the peak power of the drive motor
measured according to GB/T 18488.2. The total power of fuel cell vehicles refers to the
peak power of the drive motor measured according to GB/T 24554, in kilowatts (kW).
3.3 power to mass ratio index; PMR
the ratio of the total power of the vehicle to the test mass of the vehicle
PMR = (Pn/mt) × 1000
NOTE: The unit of power to mass ratio index is expressed in kilowatts per ton (kW/t).
3.4 reference point
the positioning point used to represent the vehicle's position when the test
vehicle performs noise measurement
NOTE 1: For a test vehicle with a front engine (drive motor), the reference point is the
foremost point of the test vehicle. For a test vehicle with a mid-mounted engine (drive
motor), the reference point is the center point of the test vehicle in the front and rear
direction. For a test vehicle with a rear engine (drive motor), the reference point is the last
end point of the test vehicle.
NOTE 2: For electric test vehicles, consider the position of the main drive motor, and
determine the reference point position of the test vehicle according to the above rules. If
there are multiple drive motors with equal power, the position of the frontmost drive motor
shall prevail.
3.5 test acceleration; atest
the average change in vehicle speed during the acceleration noise test using
the specified gear
3.6 number of gears; X
the total number of forward gears of the test vehicle that can lock the
transmission ratio (including the transmission ratio obtained by the auxiliary
transmission or the multi-speed drive axle)
3.7 exhaust system modes
the mode that, through automatic or manual selection by the driver, it changes
the direction of airflow and/or the muffling structure in the exhaust system to
produce different noise reduction effects
4 Measurement instruments
4.1 Acoustic measuring instrument
The sound level meter or other equivalent measuring system used for
measurement shall meet the requirements of the level 1 sound level meter
specified in GB/T 3785.1 (if applicable, windshield shall also be included). When
measuring, the "F" time weighting characteristics and "A" frequency weighting
characteristics of the sound level meter shall be used. When the sound level
meter or measuring system used can automatically sample and measure the
"A" weighted sound level, the reading interval shall not exceed 30ms.
4.2 Acoustic measuring instrument calibration
Before and after the measurement, it shall use a level 1 sound calibrator that is
in accordance with GB/T 15173 to calibrate. Without making any further
adjustments, if the difference between the last calibration reading and the
previous calibration reading exceeds 0.5dB(A), the measurement result after
the previous calibration is judged to be invalid.
4.3 Other measuring instruments
The measuring instrument shall include the following equipment. The accuracy
shall meet the following requirements:
a) Rotational speed measuring instrument, ±2%;
b) Vehicle speed measuring instrument, ±0.5%;
c) Thermometer, ±1°C;
d) Anemometer, ±1.0m/s;
6 Noise test
6.1 General requirements
During the measurement, the test vehicle is close to the CC' line (longitudinal
centerline), and the engine speed nmax (if applicable) shall not exceed 80% of
the rated speed.
For test vehicles with different driving modes (such as sports mode, economy
mode and adaptive mode, and so on), the driving mode can be selected. The
drive system of the test vehicle shall adopt the driving mode commonly used in
normal road driving.
For a test vehicle equipped with a multi-mode exhaust system that can be
manually selected, all exhaust system modes shall be tested as specified in 6.2.
6.2 Test items
6.2.1 Accelerated noise test
6.2.1.1 Speed conditions and acceleration range
According to the requirements of GB/T 38146.1, the speed (vPP') from the
reference point to line PP' shall be: 30km/h±1km/h, 50km/h±1km/h,
70km/h±2km/h.
The test acceleration aest shall meet the following requirements:
a) When vPP'=30km/h±1km/h, 0.5m/s2≤atest≤3.5m/s2;
b) When vPP'=50km/h±1km/h, 0.5m/s2≤atest≤3.0m/s2;
c) When vPP'=70km/h±2km/h, 0.3m/s2≤atest≤2.5m/s2.
6.2.1.2 Gear selection
6.2.1.2.1 Test vehicle that can lock the transmission ratio
The gear shall meet the following requirements:
a) When vPP'=30km/h±1km/h, the gear shall be (1+X/2)/2+1. If it is not an
integer, it shall be rounded down;
b) When vPP'=50km/h±1km/h, the gear shall be 1+X/2. If it is not an integer,
it shall be rounded down;
c) When vPP'=70km/h±2km/h, the gear shall be (X/2+X)/2+1. If it is not an
integer, it shall be rounded down.
b) For M1 vehicles with PMR≥90kW/t, two additional measurements are
allowed on the basis of a). The measured test acceleration difference shall
not be greater than 0.3m/s2. The difference between the average
acceleration of this test and the average of a) shall be greater than 0.5m/s2;
c) When the test vehicle enters line AA' or the previous pre-acceleration
position point, quickly depress the accelerator pedal to a suitable position
and keep it stable. Release the pedal until the end of the test vehicle
passes line BB'. Record vAA', vPP' and vBB' and perform test acceleration
calculation;
d) Record the maximum sound pressure level of the test vehicle each time it
passes through the measurement area. The difference between the two
maximum sound pressure levels on the same side shall not be greater
than 2dB(A). Take arithmetic average of the two maximum sound pressure
levels on each side. Take the larger of the averages on both sides as the
final result.
6.2.2 Constant speed noise test
6.2.2.1 Vehicle speed conditions
According to the requirements of GB/T 38146.1, M1 category: 80km/h±2km/h,
110km/h±2km/h; N1 category and M2 category (maximum design total mass
≤3500kg): 80km/h±2km/h, 90km/h±2km/h.
NOTE: Multi-purpose vans with PMR< 90kW/t and meeting GB/T 36881-2018, 3.1 can also
refer to the speed conditions of N1 and M2 (maximum design total mass ≤3500kg).
6.2.2.2 Gear selection
The test vehicle that can lock the transmission ratio shall be in the highest gear
that can drive stably.
For test vehicles that cannot lock the transmission ratio, the gear selector shall
be placed in the fully automatic control position.
6.2.2.3 Test methods
The constant noise test is carried out in accordance with the following rules:
a) Separately perform two measurements under each vehicle speed
condition specified in 6.2.2.1. The test vehicle shall maintain a constant
speed from entering line AA' to passing line BB' at the rear end. Record
vAA', vPP' and vBB';
b) Record the maximum sound pressure level of the test vehicle each time it
passes through the measurement area. The difference between the two
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.