Document ID: chunk:federal_register_of_legislation:F2024L00089:reg:4:p1
Version: federal_register_of_legislation:F2024L00089
Segment Type: reg
Provision Reference: reg 4 (pt 1/3)
Character Range: 73035–76446

4

 For all other test methods the derived frequency spectrum shall directly be used for the further calculation.
              4.5.1. Data compilation and reported results

              The frequency intended to be shifted shall be used for the further calculation. The frequency of the lowest reported test speed rounded to the nearest integer is taken as the reference frequency fref.

              For the other vehicle speeds, the corresponding shifted frequencies fspeed rounded to the nearest integer shall be taken from the spectra analysis. Calculate del f, the frequency shift of the signal according to equation (1):

              del f = {[(fspeed - fref)/(vtest – vref)]/fref} · 100 equation (1)

               where

               fspeed is the frequency at a given speed value;

                   fref is the frequency at the reference speed of 5 km/h or the lowest reported speed;

                   vtest is the vehicle speed, actual or simulated, corresponding to the frequency fspeed;

                   vref is the vehicle speed, actual or simulated, corresponding to the frequency fref;

               The results shall be reported using the following table:

    Table 5
Report table, to be completed for each frequency analysed
                               Test Results at Target Speeds
5 km/h                         10                             15    20
(Reference)                    km/h                           km/h  km/h
Reported Speed                 km/h
Frequency, fspeed, Left Side   Hz
Frequency, fspeed, Right Side  Hz
Frequency Shift, Left Side     %                              n.a.
Frequency Shift, Right Side    %                              n.a.

Annex 3 – Appendix
  Figures and flowcharts

    Figures 1a and 1b
Measuring positions for vehicles in motion outdoor

1a. Forward  1b. Reverse

    Figures 2a and 2b
Measuring positions for vehicles in motion indoor and in standstill

2a. Forward  2b. Reverse

       Figure 3
Minimum space to be qualified as Semi-Anechoic chamber

    Figure 4
Background Noise Parameter

    Figure 5
Vehicle A-Weighted sound pressure level measurement correction criteria

    Figure 6
Background noise requirements for analysis in one-third-octave bands

    Figure 7a
Test procedures for measurement of frequency shift

    Figure 7b
       Test procedures for measurement of frequency shift, Method A

    Figure 7c
       Test procedures for measurement of frequency shift, Methods B, C, D, and E
 [1] As defined in the Consolidated Resolution on the Construction of Vehicles (R.E.3.), document ECE/TRANS/WP.29/78/Rev.6, para. 2 - www.unece.org/trans/main/wp29/wp29wgs/wp29gen/wp29resolutions.html
 [2] At this stage, only acoustic measures shall be developed in order to overcome the concern of reduced audible signals from electrified vehicles. After finalisation, the appropriate Working Party (GR) shall be assigned with the enhancement of the Regulation in order to develop alternative, non-acoustic measures, taking into account active safety systems such as, but not limited to, pedestrian detection systems. To provide for environmental protection, this Regulation specifies also maximum limits.
 [3]  See paragraph 5.1.1. for more detailed specifications on the application.
 [4]  The maximum overall sound pressure level of 75 dB(A) measured at a distance of 2 m is corresponding to the overall sound