1. under GRPE/WLTP informal group
Development of World-wide Light-duty Test Cycle ~ Introduction of the WLTC 1st ver.~
Prepared by Japan
DHC group
under GRPE/WLTP informal group
6-7 July 2011
Stockholm, Sweden

2. In-use data collection Regional weighting In-use driving data analysis
Table of contents
Purpose
In-use data collection
Regional weighting
In-use driving data analysis
Development of WLTC 1st version
WLTP driving cycle 1st version

3. 1. Purpose
Develop the world wide harmonized light duty test cycle (WLTC) which will represent typical driving conditions around the world.
The WLTC are developed based on combination of collected in-use data and suitable weighting factors.
Data collection CP’s: EU, India, Japan, Korea, USA (and China)

4. 2. Overview of In-use data collection

5. 3.1. Regional weighting
Regional weighting when developing the unified driving characteristic is set based on Traffic volume ratio 5

6. 3.2. Internal weighting for Europe and US
Internal WF for European counties was set based on Traffic statistics (TREMOVE) and in-use driving data (vehicle speed and amount of in-use data).
Internal WF for US data was set based on US and Mr. Steven’s advice.
[Internal WF for Europe]
[Internal WF for US]

7. 4.1. driving characteristics
[Average speed]
[RPA]
disregard
disregard
[Average ST duration]
[Average IDLE duration]
disregard
disregard

8. 4.2. Unified speed acceleration distribution
[Low phase]
[Middle phase]
[High phase]
[Extra-high phase]

9. 4.3. Speed frequency distribution
[Low phase]
[Middle phase]
[High phase]
[Extra-high phase]

10. 4.4. Frequency distribution on Short trip duration
[Low phase]
[Middle phase]
[High phase]
[Extra-high phase]

11. 4.5. Frequency distribution on Idling duration
[Low phase]
[Middle phase]
[High phase]
[Extra-high phase]

12. 5.1. Determination of test cycle duration
The total test cycle duration is set at 1800 s, same as WHDC and WMTC
The test cycle duration in each phase is determined based on traffic volume ratio between L/M/H/ExH phases(*)
Low: 589 s, Mid.: 433 s, High: 455 s, Ex-High: 323 s
[Traffic volume in million vehicle-hour]
(*) Traffic volume ratio between L/M/H/ExH phases is obtained by using compensated WF and amount (duration) of data when converted from U/R/M to L/M/H/ExH

13. 5.2. Determination of No. of Short trip and Idling section
The No. of short trip and idling section in each phase are determined by using the following equation
drive cycle duration in each phase (Ti) - average idling duration
average short trip duration ＋ average idling duration
number of short trip (NST, i) =
number of idling section (NI, i) = number of short trip (NST, i) + 1
[No. of ST/IDLE section]

14. 5.3.1. Determination of Short trip duration in each phase
Cycle duration for middle phase is determined based on Idling ratio
[Low]
[Middle]
88±1s
249±1s 54
380±6s 35 19
[High]
Cycle duration for high phase is determined based on Idling ratio
[Extra-high]
Cycle duration for Extra-high phase is determined based on Idling ratio
Actual ST: 317±4 s
Combined cycle: 317 s
Actual ST: 428±6s
Combined cycle: 428 s

15. 5.3.2. Determination of Idling duration in each phase
[Low]
[Middle] 8 1 3 7
46±6 s 28 86 18
[High]
[Extra-high] 1 2
25±6 s
5±4 s

16. 5.3.3. Selection of each ST duration
it is necessary to reduce number of combinations
ST selection criteria
ST within average ±1σ in each ST duration
Average vehicle speed
Acceleration duration ratio
Deceleration duration ratio
Smaller chi-squared value is higher priority
The number of candidate STs in each ST duration
Longest ST has big influence on chi-square value => Not reduce
Shorter ST => reduce candidate STs to make total number of combinations approximately 108~9 . X1 X2 X3 X4
X5 sec.
Y sec.
N * X1/Y units
・・・
N * X4/Y
N * X5/Y units
N units

17. 5.4. The characteristics of first ST and Idling of a day
Order of Idling sections
Average Idling duration of first Idling of a day is 28 s.
Select 28 s
The final Idling duration would be more than 5 s because of stable sampling.
Select 8 s
Order of Short trips
Average speed of first short trip of a day is approx. 30 km/h. => ST of 245 s
ST of lowest speed and IDLE of longest duration are connected in order to reflect traffic jam
the order of short trips is set based on random
[The characteristics of first ST and Idling of a day by Mr. Steven]

18. 6.1. WLTP driving cycle 1st version
Vave: 28.6km/h
TID1: 28 s

19. 6.2. Characteristics of WLTC 1st version
Parameter
Cycle duration
Driving distance
Average speed
Max. speed
Max. acceleration
Max. Deceleration
driving mode (*)
Acceleration ratio
Deceleration ratio
Cruise ratio
Idling ratio
s (h) km
km/h
km/h/s %
Unified characteristics Worldwide
Low -
19.8
60.0
27.5
25.4
22.7
24.5
Middle
38.4
80.0
31.4
28.8
12.2
High
58.0
110.0
31.3
27.2
35.5
6.0
Extra-high
86.8
194.7
25.7
23.4
48.9
2.0
Unified
45.9
29.1
26.0
32.1
12.8
WLTC 1st
589
2.98
18.2
50.9
5.3
-5.3
26.1
27.8
19.7
26.3
433
5.01
41.6
72.5
5.4
-7.4
37.0
24.2
11.1
455
7.01
55.5
97.4
6.5
-7.7
29.0
35.2
7.0
323
8.06
89.8
125.5
6.4
-4.1
28.5
42.1
2.2
WLTC-unified
1800
23.06
46.1
29.9
27.1
29.6
13.4
(*) The definitions for the driving modes are given by WMTC analysis (refer to Appendix)

20. 6.3. Speed acceleration distribution of WLTC 1st version

21. 6.3. Speed acceleration distribution of WLTC 1st version

22. Appendix. Definition of driving modes
Source: TRANS-WP29-GRPE e.pdf, page.18,