2014/3/10
WLTP-06-16e
Study on
Applicability of Driving Index
(defined in SAE J2951)
to WLTC
Japan Automobile Research Institute
1
2014/3/10
< Background >
It is quite reasonable to have tolerance for each set point under the
emission/fuel consumption test procedure from the view points of
testing practicability. On the other hands, the tolerance have a
possibility to create test result variations. These variations may cause
inappropriate information to customer and/or unfair competitions.
WLTP has been trying to narrow the tolerance and to stringent the test
procedure, however, it still has a room for data variations.
European commission has been reviewing all possible flexibilities in the
WLTP gtr and their studies are under going with support of TNO and
TUG.
Japan focus on driving tracability as one of the most significant factors
since new test cycle profile has changed to micro-transient mode from
trapezium mode.
Japan Automobile Research Institute
2
2014/3/10
< Overall Test Plan >
 Test vehicles：
 Vehicle A：1.3L, Gasoline, CVT, have few difficulty to follow the trace
 Vehicle B：0.66L, Gasoline, CVT, have difficulty to follow the trace
 study how to treat WOT driving portions
 Vehicle C：2.0L, Gasoline, 6MT
 study how to treat gear shift portions
 Trace technique ： Normal (keep the target trace as much as possible),
Smoothing, Rough, Rough-2 (see below)
 # of Tests ：
Vehicle
Rough-2
Normal-1
Smooth
Rough-1
Cold
1
1
1
-
Hot
2
2
1
1
condition
60
60
Target speed
Vehicle speed [Smooth]
High limit
higher than target
40
30
20
10
Rough
Low limit
50
Vehicle speed (km/h)
Vehicle speed (km/h)
50
Target speed
Vehicle speed [Rough-1]
Smoothing
Low limit
(Slightly)
High limit
lower than target
40
30
20
10
Rough pedal operation
Smooth acceleration
0
0
0
20
Japan Automobile Research Institute
40
Time (s)
60
80
100
0
20
40
Time (s)
60
80
100
2014/3/10
< Conclusion >
 It was observed that drive trace indexes are able to detect the
unexpected driving technique (smooth or rough) and to eliminate the
inappropriate cycle trace by applying the appropriate criteria. (ASCR
and RMSSE are possible candidate indexes, on the other hands, ER,
DR and EER have weakness due to offset of positive and negative
side)
 It was observed that special treatment during wide-open-throttle
operation is necessary.
 More study on how to treat gear shift events is required.
 It was observed that negative side (smooth driving) drive trace index
has slight correlation with FC value, on the other hands, positive side
(rough driving) has no correlation with FC value.
Japan Automobile Research Institute
4
2014/3/10
< Request to all CPs >
 Evaluate the drive trace index (provide calculation tool, if necessary).
 Speed sampling rate : 10Hz (  need to modify gtr description).
< Next Actions >
 Provide specific procedure for WOT operation and gear shift events.
 Propose driving index criteria for test validity.
 Collaborate “normalization procedure” with TUG.
Japan Automobile Research Institute
5
Driving Indexes defined in SAE J2951
2014/3/10
 Engine force
•
FENG = [F0 + F1*V + F2*V2 + 1.015 * ETW * a]+
 Engine work increment
•
Wi = FENGi * di
 Cycle energy (CE)
•
CE = ΣWi = Σ[(F0 + F1*Vi + F2*Vi2 + 1.015 * ETW * ai) * di]+
 Energy rating (ER)
•
ER = (CED - CET) / CET*100
 Distance rating (DR)
•
DR = (DD - DT) / DT*100
 Energy economy rating (EER)
•
•
EER = [1 – (DR / 100 +1) / (ER / 100 +1)] * 100
Combined ER and DR
 Absolute speed change rating (ASCR)
•
•
•
ASCR = (ASCD - ASCT) / ASCT * 100
ASC = ⊿t*Σ|ai|
Integrate the acceleration (= speed fluctuation)
 Root mean squared speed error (RMSSE)
•
•
RMSSE = √(Σ(VDi - VTi)2) / N)
Integrate the difference between target speed and actual speed
Japan Automobile Research Institute
6
2014/3/10
Test results-1 (Vehicle A)

Energy rating [ER]
Normal-1
Normal-2
Smooth-1

Smooth-2
Rough-1
Rough-2
Distance rating [DR]
Normal-1
10.0
2.0
8.0
1.5
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
rough
2.0
0.0
-2.0
smooth
-4.0
WLTC CL3-2 Hot
Normal-2
rough
-1.0
WLTC CL3-2 Cold
Smooth-1
Smooth-2
Rough-2
6.0
4.0
rough
2.0
0.0
-2.0
smooth
-4.0
-6.0
-8.0
Normal-2
Smooth-1
LMHxH
LMH
ExHIGH
HIGH
Smooth-2
Rough-1
Rough-2
60
obvious difference
50
40
30
20
rough
10
0
smooth
WLTC CL3-2 Hot
Japan Automobile Research Institute
WLTC CL3-2 Cold
WLTC CL3-2 Hot
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
-10
LOW
-10.0
WLTC CL3-2 Cold
Absolute speed change rating [ASCR]
Normal-1
8.0
MID
LOW
LMHxH
LMH
ExHIGH
WLTC CL3-2 Hot

Rough-1
HIGH
LOW
LMHxH
LMH
ExHIGH
HIGH
-0.5
-2.0
10.0
Energy Economy Rating [EER]
0.0
Energy economy rating [EER]
Normal-1
smooth
0.5
-1.5
Absolute speed change rating [ASCR]

MID
LOW
LMHxH
HIGH
MID
LOW
-10.0
LMH
depends on number of
opportunity to acceleration
-8.0
1.0
MID
-6.0
Distance rating [DR]
4.0
ExHIGH
Energy rating [ER]
6.0
WLTC CL3-2 Cold
7
2014/3/10
Test results (Vehicle A)
Root mean squared speed error
[RMSSE]
WLTC CL3-2 Cold
WLTC CL3-2 Hot
LMHxH
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
0.0
Rough-2
LMH
0.2
ExHIGH
0.4
Rough-1
HIGH
0.6
MID
0.8
Smooth-2
LOW
1.0
LMHxH
1.2
Smooth-1
LMH
1.4
Normal-2
ExHIGH
RMSSE becomes higher value when
Smoothing/Rough driving
WLTC CL3-2 Hot
Normal-1
Rough-2
HIGH
Rough-1
MID
Smooth-2
LOW
1.6
Smooth-1
Impact on fuel economy
worse
Root Mean squared Error [RMSSE]
1.8
Normal-2
better
Normal-1
2.0

Rate of change of fuel economy (%)

WLTC CL3-2 Cold
 ER, DR, EER，ASCR and RMSSE became closer to zero when the
vehicle follow the target speed (Normal driving).
 In case of a smoothing or rough driving, those index values became
higher or lower value. This indicates that there is a possibility to detect
the inappropriate driving.
Japan Automobile Research Institute
8
2014/3/10
Driving indexes and fuel economy impact (vehicle A)
●LOW hot ▲MID hot ■HIGH hot ◆ExHIGH hot ●LMH hot ▲LMHxH hot ○LOW cold
△MID cold □HIGH cold ◇ExHIGH cold ●LMH cold ▲LMHxH cold

Energy rating [ER]

Distance rating [DR]

-4
-2
0
2
Energy rating [ER]
4
6
8
-2.0
-1.0
0.0
Distance rating [DR]
1.0
Absolute speed change
rating [ASCR]

worse
-6
-4
-2
0
2
4
Energy Economy Rating [EER]
6
8
0
5
10
15
Absolute speed change rating [ASCR]
Japan Automobile Research Institute
20
25
worse
better
Rate of change of fuel economy (%)
worse
-5
Root mean squared speed
error [RMSSE]
Possible criteria
better
Rate of change of fuel economy (%)
Possible criteria
-10
-8
linear relationship
linear relationship

2.0
better
Rate of change of fuel economy (%)
worse
Rate of change of fuel economy (%)
-6
better
worse
better
Rate of change of fuel economy (%)
Possible criteria
Energy economy rating
[EER] Possible criteria
0.0
0.5
1.0
Root Mean squared Error [RMSSE]
1.5
9
2014/3/10
Summary (Vehicle A)
Normal-1
Smooth-1
Rough-1
• Smooth driving: Negative value
ER
• Rough driving: Positive value
10
• Index value varies depend on each phase
5
F.E.
change rate
ER
DR(×5)
0
-5
DR
• Smooth driving: Positive value
-10
• Rough driving: Negative value
RMSSE(×5)
EER
• Difficult to detect inappropriate driving technique
EER
LMHxH cold
• Smooth driving: Negative value
ASCR
• Rough driving: Positive value
Normal-1
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
• Almost same characteristics as ER
• a significant difference according to driving techniques
ER
• linear relationship to fuel economy impact (only smooth driving)
10
ASCR
5
F.E.
change rate
0
DR(×5)
• Smooth driving: Negative value
• Rough driving: Positive value
-5
• a significant difference according to driving techniques
-10
RMSSE
RMSSE(×5)
EER
• Smooth driving: Positive value
• Rough driving: Positive value
LMHxH hot
ASCR
Japan Automobile Research Institute
• a significant difference according to driving techniques
10
2014/3/10
Consideration of special treatment during wide-open-throttle
• During acceleration events, vehicle B could NOT follow the target speed
with wide open throttle (WOT) operation.
• Need to consider how to treat in case of WOT operation.
• Special treatment: treat as same speed as target speed during WOT
operation. (index value will be over-evaluated when excluding all WOT
portions from calculation)
unable to follow despite of WOT operation
通常-1
140
通常-2
加減速少-1
加減速少-2
加減速多-1
加減速多-2
250
基準車速 km/h
車速(前後輪平均)
km/h
200
Duration for WOT (s)
100
80
60
40
100
50
1550
Japan Automobile Research Institute
1600
Time (s)
1650
1700
1750
1800
WLTC CL3-2 Hot
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
LOW
1500
HIGH
0
20
0
1450
150
MID
Vehicle speed (km/h)
Accelerator pedal angle (%)
120
WLTC CL3-2 Cold
11
2014/3/10
Test results（Vehicle B）

Energy rating [ER]

Energy rating [ER] with special treatment
Normal-1
Normal-1
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
10.0
Energy rating [ER] (w/o WOT)
6.0
Smooth-2
Rough-1
Rough-2
4.0
2.0
0.0
-2.0
-4.0
-6.0
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
-8.0
-8.0
WLTC CL3-2 Hot

Normal-1
Smooth-1
Smooth-2

Rough-1
Rough-2
1.5
1.5
Distance rating [DR] (w/o WOT)
2.0
1.0
0.5
0.0
-0.5
-1.0
-1.5
Normal-2
Smooth-1
Smooth-2
LMHxH
LMH
ExHIGH
HIGH
Rough-1
Rough-2
1.0
0.5
0.0
-0.5
-1.0
-1.5
WLTC CL3-2 Hot
Japan Automobile Research Institute
WLTC CL3-2 Cold
WLTC CL3-2 Hot
WLTC CL3-2 Cold
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
-2.0
LOW
-2.0
WLTC CL3-2 Cold
Distance rating [DR] with special treatment
Normal-1
2.0
MID
LOW
LMHxH
LMH
ExHIGH
WLTC CL3-2 Hot
WLTC CL3-2 Cold
Distance rating [DR]
Normal-2
HIGH
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
-10.0
MID
-10.0
LOW
Energy rating [ER]
Smooth-1
8.0
8.0
Distance rating [DR]
Normal-2
10.0
12
2014/3/10
Test results （Vehicle B）
Energy economy rating [EER]
Rough-2
20
15
10
5
0
-5
-10
Japan Automobile Research Institute
WLTC CL3-2 Cold
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
-15
Normal-2
Smooth-1
Smooth-2
LMHxH
LMH
ExHIGH
Rough-1
Rough-2
30
not change so much
25
20
15
10
5
0
-5
-10
-15
WLTC CL3-2 Hot
WLTC CL3-2 Cold
LMHxH
25
Normal-1
35
LMH
Rough-2
ExHIGH
Rough-1
ASCR with special treatment
LOW
Smooth-2

WLTC CL3-2 Cold
LMHxH
Smooth-1
30
LOW
LOW
LMHxH
ExHIGH
HIGH
LMH
WLTC CL3-2 Hot
35
WLTC CL3-2 Hot
-8.0
-10.0
LMH
Normal-2
-6.0
WLTC CL3-2 Cold
Absolute speed change rating [ASCR]
Normal-1
-4.0
ExHIGH

MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
WLTC CL3-2 Hot
-2.0
HIGH
-8.0
0.0
HIGH
-6.0
Rough-2
2.0
MID
-4.0
Rough-1
decrease
4.0
MID
-2.0
6.0
LOW
0.0
Smooth-2
8.0
LMHxH
2.0
Smooth-1
LMH
4.0
Normal-2
ExHIGH
6.0
Absolute speed change rating [ASCR] (w/o WOT)
Energy Economy Rating [EER]
8.0
-10.0
Absolute speed change rating [ASCR]
Normal-1
10.0
HIGH
Rough-1
HIGH
Smooth-2
MID
Smooth-1
10.0
[EER] with special treatment
MID
Normal-2
Energy Economy Rating [EER] (w/o WOT)
Normal-1

LOW

13
2014/3/10
Test results (Vehicle B）
0.8
0.6
0.4
0.2
WLTC CL3-2 Hot

LMHxH
LMH
ExHIGH
HIGH
WLTC CL3-2 Cold
1.8
1.6
Special treatment is necessary
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
WLTC CL3-2 Hot
WLTC CL3-2 Cold
Impact on fuel economy
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
WLTC CL3-2 Hot
Japan Automobile Research Institute
WLTC CL3-2 Cold
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
worse
better
Rate of channge of fuel economy (%)
Normal-1
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
0.0
Rough-2
LMHxH
1.0
Rough-1
LMH
1.2
Smooth-2
ExHIGH
1.4
Smooth-1
HIGH
1.6
Normal-2
MID
1.8
Normal-1
2.0
LOW
Rough-2
LMHxH
Rough-1
LMH
Smooth-2
ExHIGH
Smooth-1
HIGH
Normal-2
RMSSE with special treatment
MID
Root Mean squared Error [RMSSE]
Normal-1
2.0

LOW
Root mean squared speed error [RMSSE]
Root Mean squared Error [RMSSE] (w/o WOT)

14
Driving indexes(with special treatment) and fuel economy impact (vehicle B)
2014/3/10
●LOW hot ▲MID hot ■HIGH hot ◆ExHIGH hot ●LMH hot ▲LMHxH hot ○LOW cold
△MID cold □HIGH cold ◇ExHIGH cold ●LMH cold ▲LMHxH cold
-4
-2
0
2
4
6
Energy rating [ER] (w/o WOT)

8
10
-1.0
0.0
1.0
Distance rating [DR] (w/o WOT)
Absolute speed change rating
[ASCR] with special treatment

25
-4
-2
0
2
4
6
8
Energy Economy Rating [EER] (w/o WOT)
10
linear relationship
Root mean squared speed error
[RMSSE] with special treatment
worse
better
Rate of change of fuel economy (%)
Japan Automobile Research Institute
-6
Possible criteria
worse
Rate of change of fuel economy (%)
better
-5
0
5
10
15
20
Absolute speed change rating [ASCR] (w/o WOT)
2.0
Energy economy rating
[EER] with special treatment
worse
worse
-2.0
Possible criteria
-10

better
-6
Distance rating [DR]
with special treatment
better
Rate of change of fuel economy (%)

Rate of change of fuel economy (%)
Energy rating [ER] with
special treatment
worse
better
Rate of change of fuel economy (%)

0.0
0.5
1.0
Root Mean squared Error [RMSSE] (w/o WOT)
1.5
15
Driving indexes(without special treatment) and fuel economy impact (vehicle B) 2014/3/10
●LOW hot ▲MID hot ■HIGH hot ◆ExHIGH hot ●LMH hot ▲LMHxH hot ○LOW cold
△MID cold □HIGH cold ◇ExHIGH cold ●LMH cold ▲LMHxH cold
0
2
4
Energy rating [ER]
8
10
-10
0.0
Distance rating [DR]
0
5
10
15
Absolute speed change rating [ASCR]
Japan Automobile Research Institute
1.0

20
25
2.0
Energy economy rating
[EER]
worse
Rate of change of fuel economy (%)
-1.0
Absolute speed change
rating [ASCR]
-5

worse
-2.0
worse
better
Rate of change of fuel economy (%)

6
-6
-4
-2
0
2
4
6
Energy Economy Rating [EER]
8
10
Root mean squared speed
error [RMSSE]
Need special
treatment
worse
-2
Rate of change of fuel economy (%)
-4
better
-6
Distance rating [DR]
better
Rate of change of fuel economy (%)

better
Energy rating [ER]
worse
better
Rate of change of fuel economy (%)

0.0
0.5
1.0
Root Mean squared Error [RMSSE]
1.5
16
2014/3/10
Summary (Vehicle B)
Normal-1
Smooth-1
Rough-1
Normal-1
with special
treatment
ER
10
DR(×5)
0
-10
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
EER
w/o WOT
Normal-1
Normal-2
with special
treatment
ER
10
5
0
RMSSE(×5)
w/o WOT
LMHxH cold
ASCR
DR(×5)
F.E.
change rate
Smooth-1
0
-10
Japan Automobile Research Institute
RMSSE(×5)
w/o WOT
LMHxH hot
Rough-2
ASCR
• ASCR is able to detect the
smooth and/or rough driving.
RMSSE
5
-10
ASCR
Rough-1
ER
w/o WOT
10
-5
EER
Smooth-2
• could not detect
inappropriate driving
technique, due to offset
positive and negative side.
• ASCR won’t change much
when special treatment was
applied.
ASCR
w/o WOT
-5
RMSSE(×5)
DR(×5)
w/o WOT
0
-10
Normal-1
LMHxH hot
F.E.
change rate
-5
EER
F.E.
change rate
ER, DR, EER
ER
w/o WOT
10
-5
RMSSE(×5)
LMHxH cold
Rough-1
5
5
F.E.
change rate
Smooth-1
DR(×5)
w/o WOT
• RMSSE need special
treatment to detect the
smooth and/or rough driving.
EER
w/o WOT
ASCR
w/o WOT
17
2014/3/10
Test results (Vehicle C）
• During gear shift events, no tolerance is required.
• Treat as same speed as target speed during gear shift events±1sec.
gearshifting±1sec
通常-1
Vsched_l [km/h]
Gear shift [-]
Gear ±1s
120
9
100
8
7
40
6
30
5
4
20
Gear position
通常-2
加減速少-1
加減速少-2
加減速多-1
加減速多-2
80
60
40
20
3
15
20
Japan Automobile Research Institute
25
30
Time (s)
35
40
45
50
LMHxH
LMH
HIGH
MID
LOW
LMHxH
LMH
WLTC CL3-2 Hot
ExHIGH
0
10
ExHIGH
0
HIGH
1
0
MID
2
10
LOW
Vehicle speed (km/h)
50
10
Duration for gearshift (s)
60
WLTC CL3-2 Cold
18
2014/3/10
Test results (Vehicle C）
Rough-2
8.0
8.0
6.0
6.0
2.0
0.0
-2.0
-4.0
-6.0
Normal-1
WLTC CL3-2 Hot
Smooth-1
Smooth-2

Rough-1
Rough-2
1.5
1.5
Distance rating [DR] (w/o GS)
2.0
1.0
0.5
0.0
-0.5
-1.0
-1.5
Normal-2
Smooth-1
Smooth-2
Rough-1
LMHxH
Rough-2
1.0
0.5
0.0
-0.5
-1.0
-1.5
WLTC CL3-2 Hot
Japan Automobile Research Institute
WLTC CL3-2 Cold
WLTC CL3-2 Hot
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
-2.0
LOW
-2.0
WLTC CL3-2 Cold
Distance rating [DR] with special treatment
Normal-1
2.0
LMH
LOW
WLTC CL3-2 Cold
Distance rating [DR]
Normal-2
become worse!!
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
-10.0
MID
-10.0
LOW
-8.0

Rough-2
4.0
-8.0
WLTC CL3-2 Hot
Rough-1
ExHIGH
-4.0
Smooth-2
HIGH
0.0
-2.0
Smooth-1
MID
2.0
Normal-2
LOW
4.0
-6.0
Distance rating [DR]
Normal-1
10.0
LMHxH
Rough-1
LMH
Smooth-2
10.0
ExHIGH
Smooth-1
Energy rating [ER] with special treatment
HIGH
Normal-2

Energy rating [ER] (w/o GS)
Energy rating [ER]
Normal-1
Energy rating [ER]
MID

WLTC CL3-2 Cold
19
2014/3/10
Test results (Vehicle C）
Energy economy rating [EER]
Rough-2
40
30
20
10
0
-10
Japan Automobile Research Institute
WLTC CL3-2 Cold
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
-20
Normal-2
Smooth-1
Smooth-2
LMHxH
LMH
ExHIGH
Rough-1
Rough-2
60
become worse!!
50
40
30
20
10
0
-10
-20
WLTC CL3-2 Hot
WLTC CL3-2 Cold
LMHxH
50
Normal-1
70
LMH
Rough-2
ASCR with special treatment
ExHIGH
Rough-1
HIGH
LOW
LMHxH
LMH
ExHIGH
HIGH
Smooth-2

WLTC CL3-2 Cold
HIGH
Smooth-1
60
LOW
-10.0
WLTC CL3-2 Hot
70
WLTC CL3-2 Hot
-8.0
LOW
Normal-2
become worse!!
-6.0
WLTC CL3-2 Cold
Absolute speed change rating [ASCR]
Normal-1
-4.0
LMHxH

0.0
-2.0
LMH
WLTC CL3-2 Hot
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
-10.0
2.0
MID
-6.0
Rough-2
4.0
MID
-4.0
Rough-1
6.0
LOW
0.0
-2.0
Smooth-2
8.0
LMHxH
2.0
Smooth-1
LMH
4.0
Normal-2
ExHIGH
Energy Economy Rating [EER] (w/o GS)
6.0
Absolute speed change rating [ASCR] (w/o GS)
Energy Economy Rating [EER]
8.0
-8.0
Absolute speed change rating [ASCR]
Normal-1
10.0
ExHIGH
Rough-1
HIGH
Smooth-2
HIGH
Smooth-1
MID
Normal-2
10.0
[EER] with special treatment
MID
Normal-1

LOW

20
2014/3/10
Test results (Vehicle C）
0.8
0.6
0.4
0.2
WLTC CL3-2 Hot

LMHxH
LMH
ExHIGH
HIGH
WLTC CL3-2 Cold
1.8
1.6
1.4
1.2
1.0
0.8
0.6
変化小さい
0.4
0.2
0.0
WLTC CL3-2 Hot
WLTC CL3-2 Cold
Impact on fuel consumption
Normal-1
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
worse
 To treat as same speed as
target speed during gear shift
events is not effective.
 More study for gear shift
events is necessary.
WLTC CL3-2 Hot
Japan Automobile Research Institute
WLTC CL3-2 Cold
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
better
Rate of channge of fuel economy (%)
MID
LOW
LMHxH
LMH
ExHIGH
HIGH
MID
LOW
0.0
Rough-2
LMHxH
1.0
Rough-1
LMH
1.2
Smooth-2
ExHIGH
1.4
Smooth-1
HIGH
1.6
Normal-2
MID
1.8
Normal-1
2.0
LOW
Rough-2
LMHxH
Rough-1
LMH
Smooth-2
ExHIGH
Smooth-1
HIGH
Normal-2
RMSSE with special treatment
MID
Root Mean squared Error [RMSSE]
Normal-1
2.0

LOW
Root mean squared speed error [RMSSE]
Root Mean squared Error [RMSSE] (w/o GS)

21
Driving indexes(with special treatment) and fuel economy impact (vehicle C)
2014/3/10
●LOW hot ▲MID hot ■HIGH hot ◆ExHIGH hot ●LMH hot ▲LMHxH hot ○LOW cold
△MID cold □HIGH cold ◇ExHIGH cold ●LMH cold ▲LMHxH cold
0
2
4
6
Energy rating [ER] (w/o GS)
10
-10
-1.0
0.0
1.0
Distance rating [DR] (w/o GS)
Absolute speed change rating
[ASCR] with special treatment

0
10
20
Absolute speed change rating [ASCR] (w/o GS)
Japan Automobile Research Institute
2.0
worse
Energy economy rating
[EER] with special treatment
better
worse
-2.0
worse
better
Rate of change of fuel economy (%)

8

-5
0
5
Energy Economy Rating [EER] (w/o GS)
10
Root mean squared speed error
[RMSSE] with special treatment
worse
-2
Rate of change of fuel economy (%)
-4
better
-6
Distance rating [DR]
with special treatment
better
worse
Rate of change of fuel economy (%)

Rate of change of fuel economy (%)
Energy rating [ER] with
special treatment
better
Rate of change of fuel economy (%)

0.0
0.5
1.0
Root Mean squared Error [RMSSE] (w/o GS)
1.5
22
Driving indexes(without special treatment) and fuel economy impact (vehicle C)
2014/3/10
●LOW hot ▲MID hot ■HIGH hot ◆ExHIGH hot ●LMH hot ▲LMHxH hot ○LOW cold
△MID cold □HIGH cold ◇ExHIGH cold ●LMH cold ▲LMHxH cold
0
2
4
Energy rating [ER]
8
10
-1.0
-10
0.0
Distance rating [DR]
Absolute speed change
rating [ASCR]

Possible criteria
-5
0
5
10
15
Absolute speed change rating [ASCR]
Japan Automobile Research Institute
1.0
20
25
2.0
Energy economy rating
[EER]
worse
Rate of change of fuel economy (%)
worse
-2.0
worse
better
Rate of change of fuel economy (%)

6

-5
0
5
Energy Economy Rating [EER]
10
Root mean squared speed
error [RMSSE]
Possible criteria
worse
-2
Rate of change of fuel economy (%)
-4
better
-6
Distance rating [DR]
better
worse
Rate of change of fuel economy (%)

better
Energy rating [ER]
better
Rate of change of fuel economy (%)

0.0
0.5
1.0
Root Mean squared Error [RMSSE]
1.5
23
2014/3/10
Summary (Vehicle C)
Normal-1
Smooth-1
Rough-1
Normal-1
with special
treatment
ER
10
5
F.E.
change rate
DR(×5)
F.E.
change rate
-10
-10
RMSSE(×5)
w/o GS
EER
w/o GS
LMHxH cold
ASCR
ASCR
w/o GS
Normal-1
Normal-2
Smooth-1
Smooth-2
Rough-1
Rough-2
Normal-1
Normal-2
with special
treatment
ER
10
5
0
Smooth-1
DR(×5)
0
-10
-10
EER
Japan Automobile Research Institute
Rough-1
Rough-2
5
F.E.
change rate
-5
ASCR
Smooth-2
ER
w/o GS
10
-5
RMSSE(×5)
DR(×5)
w/o GS
0
-5
EER
LMHxH hot
ER
w/o GS
10
-5
RMSSE(×5)
F.E.
change rate
Rough-1
5
0
LMHxH cold
Smooth-1
RMSSE(×5)
w/o GS
It was observed that the
treatment (same as target
speed) doesn’t work for
gear shift events.
More effective treatment
during gear shift events is
necessary to adopt driving
index requirement.
DR(×5)
w/o GS
EER
w/o GS
LMHxH hot
ASCR
w/o GS
24