WLTP-DHC-05-05e rev1
WLTC* Construction
Proposed by Japan
GRPE/WLTP-IG/ DHC subgroup
14 October 2010
Rev1. 17 October 2010
*) WLTC : Worldwide harmonized Light-duty driving Test Cycle
1
WLTP-DHC-05-05e rev1
Table of Contents
Contents
1. Cycle Construction
2. Cold/Hot Start Weighting
3. Gear Shift Points
2
1. Cycle Construction
WLTP-DHC-05-05e rev1
1. Cycle Construction
1.1. Current Test Cycle in EU, US and Japan
1.2. Requirement on Test Cycle
1.3. Case Study of Cycle Construction
3
WLTP-DHC-05-05e rev1
1.1. Current Cycle Construction
Cold start
US
1372 s
10 min.soak
Urban / Rural
Hot
Motorway
Aggressive
mode
AC test
Hot start
Hot start
Hot start
505 s
600 s
765 s
600 s
Cold start
1180 s
EU
JAPAN
Cold start and
Hot start
(independent test
with preconditioning)
NA
NA
NA
NA
1204 s
According to WLTP-DHC-05-04, Urban/Rural/Motorway phase will be
converted to Low/Middle/High phase respectively.
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WLTP-DHC-05-05e rev1
1.2. Requirement on Test Cycle
Representativeness
 Driving characteristic
 Cold start (e.g. 6 or 12 hours soak)
 Hot start
intermediate soak (e.g. 10 min. soak)
warm up (e.g. 15 min. drive @ 60kph)
 Performance
Emission
Fuel consumption/GHG
Flexibility
Unique test procedure
HEV
Regeneration system
EV range
Unique Vehicle
City commuter
Low power vehicle
Target Area
Test effectiveness
Equipment restriction
Chassis dynamometer
Bag analysis duration
Minimum sample volume
Test flexibility
Human respect
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WLTP-DHC-05-05e rev1
1.3.1. Case Study of Cycle Construction
B. Based on statistical data (≒WHDC)
A. 1:1:1 (≒WMTC)
L
M
H
L
M
H
TConst
TConst
TConst
TL
TM
TH
TimeRatio k 
( = 1:1:1 )
k = L,M,H
Tk
W k
TL  TM  TH
C. Compromised way (≒LA4+HW)
L
M
TL
TM
TL+TM=1200~1372
TL:TM=WL:WM
H
TH=600~765
Ref. WLTP-DHC-03-02
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WLTP-DHC-05-05e rev1
1.3.2. Repeat Drive Cycle – A When take into account of Ki
determination of regeneration system
and/or EV range measurement, repeated
cycle procedure is one of key elements of
cycle construction.
TConst
WF :
a
L
M
L
“a” times
A. 1:1:1 (≒WMTC)
L
A1. Repeat “x” times of each mode
M
TConst
b
H
“b” times
“c” times
H
TConst
c
A2. Repeat each mode independently,
then combine.
L
L
M
H
L
L
M
M
H
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WLTP-DHC-05-05e rev1
1.3.3. Repeat Drive Cycle – B -
B. Based on statistical data (≒WHDC)
B1. Repeat complete cycle
WF :
L
M
H
TL
TM
TH
1
1
1
TimeRatio k 
k = L,M,H
L
M
H
L
M
H
Tk
W k
TL  TM  TH
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WLTP-DHC-05-05e rev1
1.3.3. Repeat Drive Cycle – C -
C. Compromised way (≒LA4+HW)
WF :
C. Repeat combined L/M mode and H mode
independently
L
M
H
TL
TM
TH
1
1
a
L
M
M
+
b
TL+TM=XXX~1372
TH=XXX~765
TL:TM=WL:WM
L
H
H
9
2. Cold/Hot Start Weighting
WLTP-DHC-05-05e rev1
2. Cold/Hot Start Weighting
2.1. How to obtain real-world emissions ?
2.2. Average Emission per Trip
2.3. Cold Start Trip Ratio
2.4. Calculation of Cold Weighting Factor
2.5. Summary
2.6. Required Data
10
2.1. How to obtain real-world emissions ?
WLTP-DHC-05-05e rev1
◆Requirements
Emission that should
be evaluated
＝
Average emission
per trip
◆Detail of average emission per trip
Emission under
cold condition
Emission during cold start trip
Emission under
hot condition
Average emission
per trip
Emission during hot start trip
Emission under
hot condition
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WLTP-DHC-05-05e rev1
2.2. Average Emission per Trip and Cold Weighting Factor
Total Emission Etotal (g/km) formula is as
following.
Cold start trip
Cold start
emission
under cold
condition
0 km
Hot start trip
Cold start
emission under
hot condition
EC
EH
Dcycle
(g/km)
(g/km)
×Rcold +
Dtrip
×(1 - Rcold)
Hot start emission
0 km
EH
(g/km)
=
EHT
(g/km)
Dtrip
ECT
(g/km)
(*) ECT = (EC * Dcycle + EH * (Dtrip – Dcycle))/ Dtrip
Etotal = ECT * Rcold + EHT * (1 – Rcold)
= (Dcycle*Rcold/Dtrip) * EC + (1-Dcycle* Rcold/Dtrip) * EH
= WFC * EC + (1 - WFC) * EH
WFC = Dcycle * Rcold / Dtrip
WFc: Cold start weighting
Rcold: Cold start trip ratio
Dtrip: Average one trip distance (km)
Dcycle: Cycle distance (km)
ECT: Cold start trip emission (g/km)
EHT: Hot start trip emission (g/km)
EC: Cold start emission (g/km)
EH: Hot start emission (g/km)
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WLTP-DHC-05-05e rev1
2.3. Cold Start Trip Ratio
Generate the cold start trip ratio by multiplying the
soak time distribution and the coolant temperature
drop ratio as the emission increase ratio
◆Frequency of soak time
Frequency
Cold start trip ratio Rcold :
Fsoak(i)
Soak time
Coolant temp. drop ratio
Coolant temp.
◆Cold start factor
R cold  Fsoak (i)  Fcold (i)
Where,
Rcold: Cold start trip ratio (= Average cold
start emission increment ratio)
Fcold(i)
Fsoak: Frequency of soak time
Ambient temp.
i
Soak time
Fcold: Cold start factor (Coolant temp. drop
ratio )
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WLTP-DHC-05-05e rev1
2.4.1. Calculation Sample
★Low/Mid. cold + Low/Mid hot + High hot
Cold Start Trip
Low/Mid. Cold
WF
Low/Mid. Hot
WLM
High Hot
WH
Dtrip
Distance (km)
Dtrip * WLM
Dc,LM
Emission
(g/km)
Mass (g)
Dtrip * WLM – Dc,LM
Dtrip * WH
ECT
EC,LM
EH,LM
EH,H
MCT
Dc,LM * EC,LM
(DT * WLM – Dc,LM) * EH,LM
(Dtrip * WH) * EH,H
◆Emission during cold start trip ECT (g/km)
ECT = MC,T / Dtrip
= (Dc,LM * EC,LM + (Dtrip * WLM – Dc,LM) * EH,LM + (Dtrip * WH) * EH,H) / Dtrip
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WLTP-DHC-05-05e rev1
2.4.2 Calculation Sample
★Low/Mid. cold + Low/Mid hot + High hot (conti.)
Hot start trip
◆Emission during hot start trip EHT (g/km)
Dtrip * WLM
Dtrip * WH
Low/Mid. Hot
High Hot
EHT = WLM * EH,LM + WH * EH,H
◆Total emission Etotal (g/km)
EH,LM
(g/km)
EH,H
(g/km)
Etotal = ECT * Rcold + EHT * (1 – Rcold)
= (DC,LM * Rcold / Dtrip) * EC,L + (WLM – DC,LM * Rcold / Dtrip) * EH,L + WH * EH,H
= WFLM,C * EC,LM + WFLM,H * EH,LM + WFH,H * EH,H
◆Cold/Hot weighting factor
WFLM,C = Dc,LM * Rcold / Dtrip
WFLM,H = WLM – Dc,LM * Rcold / Dtrip
WFH,H = WH
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WLTP-DHC-05-05e rev1
2.5. Summary
◆Calculation process
 Calculate cold start trip ratio
Generate the cold start ratio by multiplying the soak time
distribution and the coolant temperature drop ratio
 Calculate cold start WF
Generate the cold start WF based on average one trip distance
cold start trip ratio and test cycle distance
◆Required information/data
 Investigate the following two items based on actual vehicle usage
 Distribution of soak time
 Driving distance per trip
 Investigate the following based on engine bench test
 Coolant temperature drop ratio
 Other factors
 Test cycle distance
 The ratio of traffic volume in each phase (L/M/H)
In Japan, these figures
are obtained based on
survey and traffic senses.
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WLTP-DHC-05-05e rev1
2.6. Required Data -1
◆Distribution of soak time
Frequency (%)
Frequency
Soak time
0
Passenger Car
Light duty
commercial vehicle
(hour)
(%)
(%)
0.25 – 0.5
0 – 0.25
10.0
10.0
0.5– 0.75
0.25 – 0.5
11.0
11.0
0.5– 0.75
7.0
7.0
0.75 – 1.0
12.0
12.0
1.0 – 2.0
10.0
10.0
2.0 – 3.0
5.0
5.0
3.0 – 4.0
3.0
3.0
4.0 – 5.0
2.0
2.0
5.0 – 6.0
3.0
3.0
6.0 – 9.0
6.0
6.0
9.0 – 12.0
18.0
18.0
12.0 – 24.0
5.0
5.0
24.0 -48.0
3.0
3.0
48.0 -
4.0
4.0
Total
100.0
100.0
2
4
6
8
10
12
14
16
18
20
0 – 0.25
0.75 – 1.0
Soak time (hr)
1.0 – 2.0
2.0 – 3.0
3.0 – 4.0
4.0 – 5.0
5.0 – 6.0
6.0 – 9.0
9.0 – 12.0
12.0 – 24.0
24.0 -48.0
48.0 -
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WLTP-DHC-05-05e rev1
2.6. Required Data -2
◆Cold start factor
Passenger car
Light duty commercial
vehicle
Soak time
Cold start
factor
Coolant
temp.
Cold start
factor
(hour)
(℃)
(-)
(℃)
(-)
0
110
0
0 – 0.25
73
0.41
0.25 – 0.5
47
0.70
0.5– 0.75
40
0.78
0.75 – 1.0
36
0.82
1.0 – 2.0
29
0.90
2.0 – 3.0
25
0.95
3.0 – 4.0
22
0.98
4.0 – 5.0
20
1.0
5.0 – 6.0
20
1.0
6.0 – 9.0
20
1.0
9.0 – 12.0
20
1.0
12.0 – 24.0
20
1.0
24.0 -48.0
20
1.0
48.0 -
20
1.0
120
100
Coolant temp. (℃)
Coolant
temp.
80
60
40
20
0
0
2
4
6
8
10
12
Time (hr)
18
3. Gear Shift Points
WLTP-DHC-05-05e rev1
3. Gear Shift Points
3.1. Analysis Method
3.2. How to define the gear position ?
3.3. Definition of Shift Change
3.4. Factor Analysis / Frequency Distribution
3.5. Regression Analysis
3.6. Analysis Sample (JC08)
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WLTP-DHC-05-05e rev1
3.1. Analysis Method
 Developed gear shift points based on in-use survey to
represent the real driving behavior.
In-use data collection
ex. 2nd Gear Analysis
Factor analysis
Frequency distribution
2nd：Frequency
15%
10%
5%
0%
Regression Analysis
Develop Shift point equation
0
10
20
30
Speed (km/h)
40
G(x)=a*V+b*A+・・・・
80
Validation
Speed (km/h)
60


40


C
20



0
0









C





200


C


C
C






100



300


400
500
C

600
700
Time (s)
20
3.2. How to define the gear position ?
WLTP-DHC-05-05e rev1
 In case of manual gear shift, the formula for
calculating vehicle speed would be the following
if the clutch was engaged.
where,
2r  Ne
V
i t  if
V: Vehicle speed (km/h)
Ne: Engine speed (1/min)
r: radius of tire
it: Gear ratio
if: final reduction ratio
 Consequently, gear position can be defined by
calculating gear ratio during driving
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WLTP-DHC-05-05e rev1
3.3. Definition of Shift Change
Vehicle speed (km/h)
 Shift up_1: Clutch release point for up-shifting
 Shift up_2: Clutch engage point after putting in higher gear
 Shift down_1: Clutch release point for down-shifting or neutral
80
Vehicle speed
Shift up 1_Clutch off
70
Shift up 2_Clutch on
Shift down 1_Clutch off
Engine speed
Shift up 1_Clutch off
Shift up 2_Clutch on
Shift down 1_Clutch off
Gear position
Shift up 2_Clutch on
Shift up 1_Clutch off
Shift down 1_Clutch off
60
50
40
30
20
10
0
Engine speed (1/min)
4000
3000
2000
1000
0
Gear position (-)
6
5
4
3
2
1
0
0
10
20
30
40
Time (s)
50
60
70
80
90
22
3.4. Factor Analysis / Frequency Distribution
WLTP-DHC-05-05e rev1
 Calculate the vehicle speed in each gear position
(both up-shift and down-shift), then generate
various frequency distribution by each vehicle
category and analyze the factors that effect shift
operation.
 Vehicle speed frequency distribution
（0 ≤ V ≤ 100 km/h，1km/h step）
 Vehicle acceleration frequency distribution
（-10 ≤ a ≤ 10 km/h/s, 1km/h/s step）
 Engine speed frequency distribution
（600 ≤ r ≤ 6000 rpm, 100rpm step）
 Standardized engine speed frequency distribution
（0 ≤ r ≤ 100 %, 10 % step）
23
3.5.1. Regression Analysis
WLTP-DHC-05-05e rev1
 Develop the shift point equation by Stepwise selection method
Dependent variable
Explanatory variable
Remark
Vehicle speed (km/h)
Engine speed (1/min)
Normalized engine speed (%)
Acceleration (km/h/s)
Vehicle category
1: M1, 2: N1, 3: N2,,,
Fuel type
1: Petrol, 2: Diesel, 3: LPG,,,
No. of gear
Curb weight (kg)
Gear position
Maximum pay load (kg)
Gross vehicle weight (kg)
Displacement (cc)
Maximum power (kW)
Maximum torque (Nm)
Power to mass ratio (kW/t)
Torque to mass ratio (Nm/t)
Normalized vehicle weight
Wn = Curb weight / GVW
Drive train coefficient (DTC)
Refer slide 3.5.2
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WLTP-DHC-05-05e rev1
3.5.2. Drive Train Coefficient （DTC）
y = DTC * G(x)
Drive Train
if
im
Engine
Transmission
Final reduction
Differential
gear
Gear
r
Tire
2r
V 1000


im  if Ne 60
2πr / (im * if)
r
im
if
V
Ne
： running distance
per engine speed
(m)
： tire radius
(m)
： gear ratio
： final reduction gear ratio
： vehicle speed
（km/h）
： engine speed
（rpm）
Running distance
an engine revlution (m)
Power Train
0.8
Vechile A
Vehicle B
0.6
Vehicle C
0.4
0.2
0
0
1
2
3
4
5
Gear Position G(x)
DTC : Drive Train Coefficient
25
WLTP-DHC-05-05e rev1
3.6.1. Analysis Sample (JC08) - shift up speed
Vehicle A
Vehicle D
Vehicle F
Vehicle H
Vehicle J
Vehicle B
Vehicle E
Vehicle G
Vehicle I
Vehicle K
Vehicle C
10%
5%
0%
0
10
20
Speed (km/h)
3rd：Frequency
15%
10%
5%
8%
6%
4%
2%
0%
0%
30
0
10
20
30
Speed (km/h)
0
20
40
Speed (km/h)
60
40
60
80 100
Speed (km/h)
120
40
8%
5%
6%
6%
4%
4%
2%
6th：Frequency
8%
5th：Frequency
4th：Frequency
10%
15%
2nd：Frequency
1st：Frequency
20%
4%
2%
0%
0%
10
30
50
70
Speed (km/h)
90
10
30 50 70 90 110
Speed (km/h)
3%
2%
1%
0%
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WLTP-DHC-05-05e rev1
3.6.2. Analysis Sample (JC08) - downshift speed
Vehicle A
Vehicle D
Vehicle F
Vehicle H
Vehicle J
Vehicle B
Vehicle E
Vehicle G
Vehicle I
Vehicle K
Vehicle C
10
20
30
Speed (km/h)
40
5%
4%
3%
2%
1%
0%
2%
1%
Speed (km/h)
120
120
100
80
60
0%
40
80
20
20
40
60
Speed (km/h)
0
0
60
100
2%
20
40
Speed (km/h)
80
4%
0
3%
6th：Frequency
5th：Frequency
4th：Frequency
6%
0%
0%
0
6%
8%
5%
60
0%
30
10%
40
10
20
Speed (km/h)
10%
15%
20
0
20%
0
20%
3rd：Frequency
40%
0%
20%
30%
2nd：Frequency
1st：Frequency
60%
Speed (km/h)
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WLTP-DHC-05-05e rev1
3.6.3. Analysis Sample (JC08) - Explanatory variable of shift up
R2
Explanatory variable
1
2
3
4
0.752
Speed
0.815
Speed
Acceleration
0.844
Speed
Acceleration
Normalized
vehicle weight
0.847
Speed
Acceleration
Normalized
vehicle weight
DTC
0.851
Speed
Acceleration
Normalized
vehicle weight
DTC
0.851
Speed
Acceleration
Normalized
vehicle weight
DTC
0.852
Speed
Acceleration
Normalized
vehicle weight
DTC
5
6
7
Normalized
vehicle weight
@ running order
Normalized
Engine Speed @
vehicle weight
Max. torque
@ running order
Normalized
Engine Speed @ Engine speed @
vehicle weight
Max. torque
Max. power
@ running order
After completion of all data acquisition, the explanatory variable will
be determined based on stepwise selection method.
28
WLTP-DHC-05-05e rev1
3.6.4. Analysis Sample (JC08) - Explanatory variable of downshift
R2
Explanatory variable
1
2
3
4
5
6
0.552
Speed
0.629
Speed
Engine speed
0.834
Speed
Engine speed
DTC
0.841
Speed
Engine speed
DTC
Acceleration
0.845
Speed
Engine speed
DTC
Acceleration
Maximum
torque
0.846
Speed
Engine speed
DTC
Acceleration
Maximum
torque
Normalized
vehicle weight
0.848
Speed
Engine speed
DTC
Acceleration
Maximum
torque
Normalized
vehicle weight
7
Engine
capacity
After completion of all data acquisition, the explanatory variable will
be determined based on stepwise selection method.
29
3.6.5. Analysis Sample (JC08) - Gearshift equation
WLTP-DHC-05-05e rev1
 Shift up
G( x)up  2.96  0.0576  V  0.139  A  1.81  Wn  3.36  DTC
 Shift down
G ( x) down  5.12  0.0924  V  0.043  A  0.00129  E  25.9  DTC
G(x)
V
A
Wn
E
DTC
:Gearshift equation
:Speed in km/h
:Acceleration in km/h/s
:Normalized vehicle weight (Curb weight / GVW)
:Engine speed in rpm
:Drive train coefficient
After completion of all data acquisition, the gearshift
equation for WLTC will be developed.
30
WLTP-DHC-05-05e rev1
3.6.6. Analysis Sample (JC08) – Final Shift Points
0.18
 Vehicle Categorization
Drive train coefficient
 Passenger Car
 Light Duty
Commercial Vehicle
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.4
0.5
0.7
0.8
Nomalized vehicle weight Wn
0.9
1.0
Average of LDCV
Average of PC
Wn=0.58, DTC=0.09
Wn=0.80, DTC=0.11
◆for Passenger cars
◆for Light duty commercial vehicles
100
100
90
90
80
80
⑥
⑥
70
70
⑤
60
④
50
⑤
⑤
④
④
④
④
④
Speed (km/h)
Speed (km/h)
0.6
④
40
③
③
③
30
②
②
20
C
②
③
③
③
②
②
C
②
C
②
②
C
②
C
C
①
0
①
100
①
200
①
300
①
400
500
①
②
②②
C
①
①
800
①
900
⑤
⑤
④
40
②
④
③
②
C
②
10
④
③
③
③
20
C
600
700
Time (s)
⑤
⑤
50
30
C
C
0
③③
③
C
10
③
③
60
C
C
③
②
④
④
④
③
C
②
③
②
③
②
②
C
②
③
③
③
③
C
C
②
② C ②
C
C
C
①
1000
①
0
①
1100
1200
1300
0
①
100
①
200
①
300
①
400
500
①
①
600
700
Time (s)
①
800
①
900
①
1000
①
1100
1200
1300
31