WLTP ROAD LOAD FAMILY
BMW, 31.10.2014Christoph Lueginger
PROPOSAL ON A FAMILY DEFINITION FOR ROAD LOAD DETERMINATION
WLTP-08-19e
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WLTP ROAD LOAD FAMILYINTRODUCTIONAgenda:
1. Validation testing, current status and program.
2. Current proposal.
Minutes of Geneva-meeting 06/2014:
WLTP Road Load Family, BMW, 31.10.2014
320i ed - AT 320d - AT 328i - AT 435i - AT5.0
7.0
9.0
11.0
13.0
15.0
17.0
19.0
cycle
energ
y W
LTP [M
J]
1.3
1.4
1.2
1.34.0 MJ
sedan
sedan
wagon convertible
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WLTP ROAD LOAD FAMILY VALIDATION TESTS
measurement program - road load family validation
1.4 MJ
1.3 MJ
1.3 MJ
WLTP Road Load Family, BMW, 31.10.2014
The difference between the vehicles is a first guess and will be determined precisely by component measurements (weight, aerodynamics, RR).
The measurements of the first two vehicles is in progress, finalization is planned for end of 2014, if the weather in Munich allows coast down testing, otherwise mid of 2015.
320i ed - ATRRAeromass
435i- ATRRAeromass
328i - ATRRAeromass
320d - ATRRAeromass
Starting from the CO2 family and dropping the engine related issues, the following definition results.
Proposal for definition of a "road load family":• Vehicles identical with respect to the following characteristics shall be
considered to be part of the same road load family:
• (a) Transmission type (e.g. manual, automatic, CVT) and transmission model (e.g. torque rating, number of gears, number of clutches, etc.);
• (b) n/v ratios (engine rotational speed divided by vehicle speed). This requirement shall be considered fulfilled if, for all transmission ratios concerned, the difference with respect to the transmission ratios of the most commonly installed transmission type is within: [25] per cent; can be much bigger than for the CO2-family, influence very small, criteria could even be deleted!?
• (c) Number of powered axles;
• (d) [RESERVED: family criteria for EVs]. Out of the EV criteria there might be also criteria to be taken into account for the road load family, especially if the electric machine is not decoupled!
• The range between the vehicle with the lowest energy demand over a full WLTC class 3 and the vehicle with the highest energy demand shall not exceed [5] MJ.
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WLTP ROAD LOAD FAMILYROAD LOAD FAMILY DEFINITION PROPOSAL
from WLTP-DTP-LabProcICE-172 - Comparison RLD flatbelt_VW.pdf
WLTP Road Load Family, BMW, 31.10.2014
1. Results of validation measurements.
2. Is there input or feedback from other participants?
3. Please give your feedback on first draft provided.
Members of TF:Contact Persons: Rob Cuelenaere (TNO), Christoph Lueginger (BMW)
Experts: Markus Bergmann (Audi), Norbert Ligterink (TNO), Toshihisa Yamaguchi (Japan), Annette Feucht (Audi), Nakhawa (India), Iddo Riemersma (T&E), Bill Coleman (VW), Caro Hosier (Ford), Laura Bigi (PSA), Bob Latu (Renault), Bertrand Mercier (PSA), Helge Schmidt (TÜV Nord), André Rijnders (RDW), Klaus Steininger, (EU Com), Beatrice Lopez (UTAC), Folko Rohde (VW), Kai Behlau (VW)
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WLTP ROAD LOAD FAMILYNEXT STEPS
WLTP Road Load Family, BMW, 31.10.2014
Backup
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WLTP ROAD LOAD FAMILYBACKUP
from WLTP-DTP-LabProcICE-172 - Comparison RLD flatbelt_VW.pdf
WLTP Road Load Family, BMW, 16.10.2014
• In the current GTR two coast downs are necessary for one CO2-family.
• Coast down testing is very time consuming and inflexible (weather, track capacity, …)
• Many parameters that must be equal within one CO2-family (for good reasons) have no other effect on the road load except for their effect on weight and aerodynamics which is accounted for in the interpolation.
• Example: The engine is decoupled during coast down, therefore neither the engine type nor the engine temperature is relevant for road load determination.
• A definition of a road load family, that is bigger than the CO2-family, is possible.
• A road load family avoids unnecessary workload without losing accuracy.
• Such a family has synergistic effects e.g. a family for the alternative warm-up procedure could also be this road load family.
If the concept of developing a road load family is agreed, the details should be worked out in a small subgroup.
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WLTP ROAD LOAD FAMILYSTATUS AND INTRODUCTION
WLTP Road Load Family Concept, BMW, 10.03.2014
from WLTP-DTP-LabProcICE-172 - Comparison RLD flatbelt_VW.pdf
• The engine has no influence on road load, as it is decoupled, apart from:
• Weight, aerodynamic (and rolling resistance) influences. They are covered by the calculation of the individual road load coefficients!
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WLTP ROAD LOAD FAMILYCLARIFICATION OF ROAD LOAD INFLUENCES
WLTP Road Load Family Concept, BMW, 10.03.2014
from WLTP-DTP-LabProcICE-172 - Comparison RLD flatbelt_VW.pdf
not relevantfor road
load
influences on road load
assessed by
masscombined approach
rolling resistancecombined approach
aerodynamicscombined approach
drivetrain type (2WD/4WD)
tbd inroad load family
drivetrain lossestbd inroad load family
gearbox type (MT, AT, …)
tbdroad load family
• 3.2.3.2.2.4. Calculation of road load for individual vehicles in the CO2 vehicle family
• 3.2.3.2.2.5. Calculation of cycle energy per phase
• 3.2.3.2.2.6. Calculation of the CO2 value for an individual vehicle by the CO2 interpolation method
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WLTP ROAD LOAD FAMILYCALCULATION OF ROAD LOAD INFLUENCES, ANNEX 7
WLTP Road Load Family Concept, BMW, 10.03.2014
from WLTP-DTP-LabProcICE-172 - Comparison RLD flatbelt_VW.pdf
Formulas forroad load family
Formulas forboth families
Formulas forCO2-family
4. RLD – Family 5 series AT Gasoline / Diesel
2. RLD – Family 3 series AT Gasoline / Diesel
1. RLD – Family 3 series MT Gasoline / Diesel
WLTP – FAMILY DEFINITIONSEXAMPLE WITH LIMITED PARAMETERS
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3. RLD – Family 5 series MT Gasoline / Diesel
1. ATCT Family,Diesel MT / AT
2. ATCT Family,Gasoline MT / AT
2. ATCT Family,Gasoline MT / AT
CA Family 3 series
MT Gasoline
CA Family 3 series
MT Diesel
CA Family 3 series
AT Diesel
CA Family 5 series
MT Gasoline
CA Family 5 series
MT Diesel
CA Family 5 series
ATDiesel
CA Family 5 series
AT Gasoline
CA Family 3 series
AT Gasoline
RLD: Road Load DeterminationATCT: Ambient Temperature Correction TestCA: Combined Approach