1. WLTP-DTP-LabProcICE-229
Vehicle warm up and dyno load setting
Common proposal
Y. Aoyama, Japan
M. Bergmann, Audi

2. Warm up on the road – current proposal
120 km/h for at least 20 min
T = 5 – 35 °C
The maximum time will depend on the chosen vehicle and the atmospheric conditions
Stability criteria given in gtr:
M. Bergmann, AUDI

3. Vehicle warm up on dyno – R83
T = 20 – 30 °C
R83, Annex4, Appendix 3: Bring the vehicle and dynamometer to operating temperature in a suitable manner.
Common practice: NEDC for warm up
M. Bergmann, AUDI

4. Vehicle warm up on dyno - OIT solution 1 and 2
120 km/h for at least 20 min
T = 23 °C, restiricted airflow not representative (no windtunnel)
Objective: Same vehicle conditions as during road load determination
Concern: vehicle is warmed up too much due to limited cooling fan capacity and bent surface of dyno rollers.
M. Bergmann, AUDI

5. Dyno load setting procedures – 2 possible methods
(…)
Fixed run method
Standard method
High repeatability
High stability
Duration dependent on the warm up procedure
High repeatability
Stability not relevant
1st setting
after first run
2nd setting – average of
2nd and 3rd coastdown
X runs for
dyno setting
2 runs within the limits
Fixed run method
Short method, fixed number of coastdowns
No check of the resulting values
Standard Method
Number of coastdowns unknown
Stability demonstrated after two consecutive runs within the limits (±10 N)
Vehicle is being cooled down if accelerated by dyno.
M. Bergmann, AUDI

6. Vehicle warm up on dyno - New proposal
Respective WLTC (cold start)
T = 23 °C
Objectives:
stable and repeatable coastdown times
Vehicle is in the same condition as during/at the end of the WLTC
M. Bergmann, AUDI

7. Validation of a alternative warm up procedure
Alternative warm up cycle
WLTC
within the limit ?
Valid dyno set values
Valid dyno set values
Yes
alternative warm up cycle is valid, within the specific family.
If the coastdown after a WLTC with the new dyno set values is within the limits of ± 10 N (standard coastdown method), the alternative warm up procedure is valid within the specific family.
M. Bergmann, AUDI

8. Proposal
On the road: 120km/h steady speed or 90% maximum speed of applicable WLTC until stabilized (at least 20min.)
On the dyno: WLTC as a warm up cycle
Warm up is representative for WLTP testing
120km/h on road  WLTC 5.3
90% max. speed of applicable WLTC  the applicable WLTC.
For consecutive dyno load setting (i.e. same vehicle, different target road load)  applicable WLTC ‚phase‘ which has max. speed. (High or Ex-High)
If the manufacturer develops an alternative warm up cycle/procedure, equivalency can be shown as follows:
Perform a warm up and dyno load setting with the alternative warm up cycle
Coast down the vehicle after a cold start WLTC. If the coastdown after WLTC with the new dyno set values is within the limits of ± 10 N, the alternative warm up procedure is deemed to be equivalent to a WLTC.
This alternative warm up cycle can be used within the specific family.
Dyno load setting procedure.
Accelerated by dyno.  Fixed run method.
Accelerated by vehicle  Fixed run method or Standard method.
Acceleration rate : v * a >= 6m2/s3
M. Bergmann, AUDI