Calculation of default road load based on vehicle 5.2. 5.2. f0, N default parameters f1, N/(km/h) * (calc.) f2, N/(km/h)² Measurement of road load within labs by wind 6. 6.7.3. f0, N tunnel and a dynamometer f1, N/(km/h) wind f2, N/(km/h)² tunnel - with a flat belt dynamometer - - with stabilised speeds or with deceleration - - - with warm-up by driving or warm-up by dragging the vehicle - with a roller chassis dynamometer plus correction function - - with stabilised speeds or with deceleration - - - with warm-up by driving or warm-up by dragging the vehicle * This coefficient is set to zero for this method. 402. The characteristic differences between these methods are shown in Table 12. Table 12 Characteristic differences between the road determination methods Method Coast down Torque meter RL matrix family Default RL Wind tunnel passenger vehicles passenger large vans for small passenger vehicles Focus/scope vehicles, above 3 tons series wheel hub motor max. laden mass velocities and wheel torque at (extrapolate nothing is air drag and drivetrain Measured times during coast constant speeds measured RL) measured plus RR losses value down + well known + shorter test + balanced +cheapest + reproducible and Positive and + simple track compromise method weather independent negative measurement + measures "real" between test + no test + accuracy attributes equipment road load effort and effort + suitable for secret - long test track - weather accuracy - worst case designs needed dependent - slightly worse road load - expensive equipment - weather - complex process road load dependent (safety margin) - inaccurate
default (calc.) Calculation of default road load based on vehicle parameters 5.2. 5.2. f0, N f1, N/(km/h) * f2, N/(km/h)² wind tunnel Measurement of road load within labs by wind tunnel and a dynamometer 6. 6.7.3. f0, N f1, N/(km/h) f2, N/(km/h)² - with a flat belt dynamometer - - with stabilised speeds or with deceleration - - - with warm-up by driving or warm-up by dragging the vehicle - with a roller chassis dynamometer plus correction function - - with stabilised speeds or with deceleration - - - with warm-up by driving or warm-up by dragging the vehicle * This coefficient is set to zero for this method. 402. The characteristic differences between these methods are shown in Table 12. Table 12 Characteristic differences between the road determination methods Method Coast down Torque meter RL matrix family Default RL Wind tunnel Focus/scope passenger vehicles passenger vehicles, wheel hub motor large vans above 3 tons max. laden mass for small series passenger vehicles Measured value velocities and times during coast down wheel torque at constant speeds (extrapolate measured RL) nothing is measured air drag and drivetrain plus RR losses Positive and negative attributes + well known + simple measurement equipment - long test track needed - weather dependent - inaccurate + shorter test track + measures "real" road load - weather dependent - complex process + balanced compromise between test effort and accuracy - slightly worse road load (safety margin) +cheapest method + no test effort - worst case road load + reproducible and weather independent + accuracy + suitable for secret designs - expensive equipment
ECE-TRANS-180a15am2app1e.docx