Document ID: chunk:federal_register_of_legislation:F2024L00446:reg:16:p28
Version: federal_register_of_legislation:F2024L00446
Segment Type: reg
Provision Reference: reg 16 (pt 28/108)
Character Range: 962991–966415

of this annex until the tolerance is satisfied.
              8.1.4. Adjustment
              The chassis dynamometer setting load shall be adjusted according to the following equations:
            Therefore:
                      where:
                  Fdj is the initial chassis dynamometer setting load, N;
                   is the adjusted chassis dynamometer setting load, N;
                  Fj is the adjustment road load equal to , N;
                  Fsj is the simulated road load at reference speed vj, N;
                  Ftj is the target road load at reference speed vj, N;
                       are the new chassis dynamometer setting coefficients.
              8.1.5. At, Bt and Ct shall be used as the final values of f0, f1 and f2, and shall be used for the following purposes:
                  (a) Determination of downscaling, paragraph 8. of Annex B1;
                  (b) Determination of gearshift points, Annex B2;
                  (c) Interpolation of CO2 and fuel consumption, paragraph 3.2.3. of Annex B7;
                  (d) Calculation of results of electric and hybrid-electric vehicles, paragraph 4. of Annex B8.
              8.2. Chassis dynamometer load setting using the torque meter method
              This method is applicable when the running resistance is determined using the torque meter method described in paragraph 4.4. of this annex.
              In the case of a road load matrix family, this method shall be applied when the running resistance of the representative vehicle is determined using the torque meter method as specified in paragraph 4.4. of this annex. The target running resistance values are the values calculated using the method specified in paragraph 5.1. of this annex.
              8.2.1. Initial load setting
              For a chassis dynamometer of coefficient control, the chassis dynamometer power absorption unit shall be adjusted with the arbitrary initial coefficients,  , of the following equation:
           where:
            is the chassis dynamometer setting load, N;
            is the speed of the chassis dynamometer roller, km/h.
           The following coefficients are recommended for the initial load setting:
                  (a)
                  For single-axis chassis dynamometers, or

                  For dual-axis chassis dynamometers, where:
                  are the target running resistance coefficients; and
                  r' is the dynamic radius of the tyre on the chassis dynamometer obtained at 80 km/h, m, or
                  (b) Empirical values, such as those used for the setting for a similar type of vehicle.
              For a chassis dynamometer of polygonal control, adequate load values at each reference speed shall be set for the chassis dynamometer power absorption unit.
              8.2.2. Wheel torque measurement
              The torque measurement test on the chassis dynamometer shall be performed with the procedure defined in paragraph 4.4.2. of this annex. The torque meter(s) shall be identical to the one(s) used in the preceding road test.
              8.2.3. Verification
              8.2.3.1. The target running resistance (torque) curve shall be determined using the equation in paragraph 4.5.5.2.1. of this annex and may be written as follows:
              8.2.3.2. The simulated running resistance (torque) curve on the chassis dynamometer shall be calculated