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  1. General
  2. Extraction of parameters from measurements according to Annex 3
     
    1.                         The procedure set out in this Annex requires the performance of type approval tests in accordance with Annex 3.              
       

If the tests according to Annex 7 are carried out in the course of type approval, all tests either for Annex 3 or for Annex 7 shall be carried out on the same test track or same indoor facility and under similar environmental conditions.

 

If Annex 7 tests are carried out when type approval has already been granted, e.g. during tests for conformity of production or for in-use compliance, the tests in motion specified in Annex 3 may be carried out with the same mode, gear(s)/gear ratio(s), gear weighting factor k and partial power factor k P as determined during the type approval process, provided these information are available from the type approval test for the applicable vehicle variant of the family.              
 

2.2.                            Determination of reference data from Annex 3
 

2.2.1.                       The necessary reference data to establish the sound estimation model are taken from the pass-by and – if applicable – from the cruise-by test of one gear of the Annex 3 type approval test.              
 

2.2.1.1.                 In the case the test has been carried out with two gear ratios, the reported parameters for gear i shall be selected. In the case the test has been carried out in a single gear, the reported parameters for this single gear shall be selected.              
 

2.2.1.2.                 The Parameters taken from Annex 3 tests are in all cases the arithmetic average of the four valid runs as determined by the measurements in Annex 3. Engine speed is not requested for Annex 3. However, for the purpose of Annex 7 it needs to be measured.

The parameters to be reported from the acceleration test are:

-             The sound pressure level L WOT,REP which is the higher value of the measured sound pressure levels of the left and right side of the vehicle, rounded to the first decimal.

-             The vehicle speed v BB,WOT,REP when the rear of the vehicle passes line BB’, rounded to the first decimal

-             The engine speed n BB,WOT,REP when the rear of the vehicle passes line BB’, rounded to a 10 min -1 .


The parameters to be reported from the constant speed test are:

-             The sound pressure level L CRS,REP which is the higher value of the measured sound pressure levels of the left and right side of the vehicle, rounded to the first decimal.

-             The reference vehicle speed is 50 km/h, unless the vehicle was tested in Annex 3 at a different vehicle speed. In this case use the reported vehicle speed v BB,CRS , rounded to the first decimal.

-             The engine speed n BB,CRS,REP when the rear of the vehicle passes line BB’, rounded to a 10 min -1 .              
 

2.3.                            Selection of parameter coefficients
The necessary coefficients are dependent on the vehicle design and listed in table 1 in the Appendix to this.              
 

2.4.                            Calculate the Reference Tyre/Rolling Sound Level L REF,TR

 

 

2.5.                            Calculate the Reference Power Train Mechanics Sound Level L REF,PT

 

 

2.6.                            Calculate the Reference Dynamic Sound Level L REF,DYN

 

 

2.7.                            Determine the Vehicle Dynamic Delta Sound Level ∆L DYN


If the arithmetic sound level difference between the reported acceleration sound level L WOT,REP and the reported constant speed sound level L CRS,REP is at least 1.1 dB or higher, the vehicle dynamic delta sound level ∆L DYN is  calculated by              

 

 

with

 


 

 

 

If the arithmetic sound level difference between the reported acceleration sound level L WOT,REP and the reported constant speed sound level L CRS,REP is less than 1,1 dB, the vehicle dynamic delta sound level ∆L DYN is  set to 10 dB(A).              

 

 

2.8.                            For a better understanding on the procedure, guidance is provided by the flowchart 2 of Appendix 2 to Annex 7.              
 

2.9.                            Having established the sound estimation model for a given vehicle based on its particular pass-by test results according to Annex 3 of this Regulation; proceed to the single point evaluation for each test runs performed according to paragraphs 2.4 and 2.5 of Annex 7.              

  1. Calculation of the expectation sound level L EXP,TEST
    1.                         For each single test run performed for the purpose of Annex 7, an expectation sound level L EXP,TEST shall be calculated.              

The flowchart in the Appendix to Annex 7 provides guidance through the necessary calculation steps provided by the following paragraphs.              

3.2.                            Necessary input data for the sound model, taken from the pass-by measurement according to paragraph 2.5.2. of Annex 7

3.2.1.                       For the calculation of the expectation sound level the parameters listed for an ASEP test run has to be reported:

  • The sound pressure level L TEST , taken as the higher maximum pass-by sound pressure level for left or right side of the vehicle, rounded to the first decimal
  • The vehicle speed v BB’,TEST when the rear of the vehicle passes line BB’, rounded to the first decimal
  • The engine speed n BB’,TEST when the rear of the vehicle passes line BB’, rounded to 10 min-1. See as well 3.2.2. below
  • The acceleration a TEST determined for measurements under acceleration, either between line PP’ and line BB’, rounded to the second decimal, according to the provisions of paragraph 2.5.3.1. of Annex 7.
    • The gear ratio i TEST , expressed in km/h per 1000 min -1 and calculated by the formula below, rounded to the second decimal              

 

3.2.2.                       Virtual engine speed for vehicles without internal combustion engine

When testing vehicles without an internal combustion engine for direct forward propulsion, an engine speed will not be available. In such cases the engine speed is simulated on the basis of the measured vehicle speed v BB’,TEST by using a virtual uniform gear ratio of [20] km/h per 1000 min -1 .

 

3.3.                            Calculation of expected tyre rolling sound component L TR,EXP

The expected tyre rolling sound component L TR,EXP is calculated dependent on the achieved vehicle speed v BB,TEST during the test.

For vehicles speeds up to and inclusive 50 km/h, L TR,EXP is calculated by

with

 

For vehicle speeds v BB,TEST exceeding 50 km/h, L TR,EXP is calculated by

with

 

3.4.                            Calculation of expected power train mechanics sound component L PT,EXP

The expected power train base mechanic sound component L PT,EXP is calculated dependent on the achieved engine speed n BB,TEST during the test.

For engine speeds up to and inclusive n BB,CRS,REP , L PT,EXP is calculated by


 

with

 

For vehicle speeds v BB,TEST exceeding 50 km/h, L TR,EXP is calculated by


 

with


 

3.5.                            Calculation of expected base dynamic sound component L DYN,EXP

The expected base dynamic sound component L DYN,EXP is calculated dependent on the achieved engine speed n BB,TEST during the test.

For engine speeds up to and inclusive n BB,WOT,REP , L PT,EXP is calculated by


 

with

 

For vehicle speeds v BB,TEST exceeding 50 km/h, L TR,EXP is calculated by


 

with



 

3.6.                            Calculation of expected dynamic delta sound component L DYN,EXP

3.6.1.                       Determination of the maximum reference acceleration a MAX,REF

3.6.1.1.                 The reference acceleration a MAX,REF is the maximum acceleration performance determined in a low gear following the recommendations below:              

A pass-by test shall be performed in a gear ratio and at a vehicle entry speed such, that the vehicle engine speed n BB’ is between the n MAX,TORQUE and S.

n MAX,TORQUE is the engine speed, where the vehicle develops its maximum torque. If the maximum torque is reached at several engine speeds, the highest engine speed should be taken as n MAX,TORQUE .

This operation condition is determined by the vehicle manufacturer in agreement with the authority present during the test. For efficiency, this operation condition may be taken as one operation condition, provided the boundary conditions according paragraph 2.3. are met.              

The acceleration a MAX,REF is calculated according to the formula of paragraph 3.1.2.1.2.2. of Annex 3 between line PP’ and BB’. 

3.6.2.                       Calculation of the load portion LOAD TEST achieved during the test run

The load portion as fractal of the maximum load is calculated based on the achieved acceleration a TEST , relative to the reference acceleration a MAX,i with the formula below
 

with
 

3.6.3.                       Performance related calculations

3.6.3.1.                 Calculation of the performance va TEST

The performance achieved during the test is calculated from the achieved acceleration expressed in m/s² and the vehicle speed expressed in km/h by              


 

3.6.3.2.                 Calculation of the dynamic performance component ∆L DYN,va

The dynamic performance component of the vehicle dynamic sound is calculated as based on the achieved per va TEST relative to a reference performance.

If the achieved performance does not exceed the reference performance va REF according to the parameter coefficient table 1 , the dynamic performance component ∆L DYN,va is equal zero.

If the achieved performance exceeds the reference performance, the dynamic performance component ∆L DYN,va is calculated by              
 

with β = [16]

 

3.6.3.3.                 Aggregation of dynamic sound components

The final dynamic delta sound component L DYN,EXP dynamic is calculated by

with

 

3.7.                            Calculation of the expectation sound level L TEST,EXP

The calculation results of the paragraphs 3.3. to 3.6. are used to calculate the expectation sound level for an individual to be compared with the measured maximum sound pressure level, by the following formula              


 

3.8.                            Proceed with the compliance assessment according to paragraph 3 of Annex 7