Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:1714:p13
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 1714 (pt 13/15)
Character Range: 723518–726545

a different value for deceleration phases (nmin_drive_down).
                  Samples which have acceleration values ≥ -0.1389 m/s² shall belong to the acceleration/constant speed phases. This phase specification shall only be used for the determination of the initial gear according to paragraph 3.5. of this annex and shall not be applied to the requirements specified in paragraph 4. of this annex.
                  In addition, for an initial period of time (tstart_phase), the manufacturer may specify higher values (nmin_drive_start or nmin_drive_up_start and nmin_drive_down_start) for the values nmin_drive or nmin_drive_up and nmin_drive_down for ngear > 2 than specified above.
                  The initial time period shall be specified by the manufacturer but shall not exceed the low speed phase of the cycle and shall end in a stop phase so that there is no change of nmin_drive within a short trip.
                  All individually chosen nmin_drive values shall be equal to or higher than nmin_drive_set but shall not exceed (2 × nmin_drive_set).
                  All individually chosen nmin_drive values and tstart_phase shall be recorded.
                  Only nmin_drive_set shall be used as the lower limit for the full load power curve according to paragraph 2(h) above.
                  (l) , test mass of the vehicle, kg.
              3. Calculations of required power, engine speeds, available power, and possible gear to be used
              3.1. Calculation of required power
              For each second j of the cycle trace, the power required to overcome driving resistance and to accelerate shall be calculated using the following equation:
           where:
                     Prequired,j  is the required power at second j, kW;
                     aj is the vehicle acceleration at second j, m/s², and is calculated as follows:
                     ;
              j = tstart to tend – 1,
                     tstart is the time at which the applicable test cycle starts (see paragraph 3 of Annex B1 of this Regulation), s;
                     tend is the time at which the applicable test cycle ends (see paragraph 3 of Annex B1 of this Regulation), s;
              The acceleration value at second tend (second 1611 for class 1 cycle and second 1800 for class 2 and 3 cycles) may be set to 0 in order to avoid empty cells.
                     kr is a factor taking the inertial resistances of the drivetrain during acceleration into account and is set to 1.03.
              3.2. Determination of engine speeds
              For any vj < 1.0 km/h, it shall be assumed that the vehicle is standing still and the engine speed shall be set to nidle.The gear lever shall be placed in neutral with the clutch engaged except 1 second before beginning an acceleration from standstill where first gear shall be selected with the clutch disengaged.
              For each vj ≥ 1.0 km/h of the cycle trace and each gear i, i = 1 to ng the engine speed, ni,j , shall be calculated using