Division 8.2.1 Downscaling procedure for Class 1 vehicles

Figure A1/14 shows a downscaled medium speed phase of the Class 1 WLTC as an example.

For the Class 1 cycle, the downscaling period is the time period between second 651 and second 906. Within this time period, the acceleration for the original cycle shall be calculated using the following equation:

a_{{orig}_{i}} = \frac{v_{i + 1} - v_{i}}{3,6}

where:

v_i

is the vehicle speed, km/h;

is the time between second 651 and second 906.

The downscaling shall be applied first in the time period between second 651 and second 848. The downscaled speed trace shall be subsequently calculated using the following equation:

v_{{dsc}_{i + 1}} = v_{{dsc}_{i}} + a_{{orig}_{i}} \times (1 - f_{dsc}) \times 3,6

with i = 651 to 847.

For i = 651, $v_{{dsc}_{i}} = v_{{orig}_{i}}$

In order to meet the original vehicle speed at second 907, a correction factor for the deceleration shall be calculated using the following equation:

f_{corr_dec} = \frac{v_{dsc_848} - 36,7}{v_{orig_848} - 36,7}

where 36,7 km/h is the original vehicle speed at second 907.

The downscaled vehicle speed between second 849 and second 906 shall be subsequently calculated using the following equation:

v_{{dsc}_{i}} = v_{{dsc}_{i - 1}} + a_{{orig}_{i - 1}} \times f_{corr_dec} \times 3,6

for i = 849 to 906.