WLTC* methodology. Proposed by Japan (Reviewed by UK, JRC and Mr. Steven) DHC group under GRPE/WLTP informal group

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1 WLTP-DHC--3e WLTC* methodology Proposed by Japan (Reviewed by UK, JRC and Mr. Steven) DHC group under GRPE/WLTP informal group 11~ January 11 Palais des Nations, Geneva (*) WLTC : Worldwide harmonized Light duty driving Test Cycle 1

2 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of High cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High

3 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of high cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High 3

1. Purpose WLTP-DHC--3e Develop the world wide harmonized light duty test cycle, which will represent typical driving conditions around the world Define the methodology to develop

4 1. Purpose WLTP-DHC--3e Develop the world wide harmonized light duty test cycle, which will represent typical driving conditions around the world Define the methodology to develop the WLTC drive cycle The WLTC drive cycle will be developed based on combination of collected in-use data and suitable weighting factors. China, EU, India, Japan, South Korea, USA

5 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of high cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High 5

6 .1. Overall process Task of DHC Group Work Classification of Influencing Parameters WLTP-DHC--3e Task of DTP Group Work PM/PN Collections of In-use driving data Collections of statistics on LD vehicles use ICE-Lab. process Determine weighting factor E-Lab. process Gearshift analysis Gearshift prescription Development of Reference Database Re-categorization into L/M/H Development of initial WLTC Validation tests 1 PCs / LDCVs Urban / Rural / Motorway Peak / Off peak / Weekend Low / Middle / High Cold / Hot ratio Engine On -> Vehicle take-off time etc Additional pollutant Reference fuel Modification Short trip & gearshift points input from DTP subgroup Confirmation tests Validation tests Round robin tests Modification Short trip & gearshift points WLTC (*) Remark DHC : Development of worldwide Harmonized light duty driving Cycle DTP : Development of Test Procedure WLTC : Worldwide harmonized Light duty driving Test Cycle

7 Basic concept WLTP-DHC--3e Common test cycle is developed based on collected in-use data and weighting factor. Weighting factor matrix and In-use driving data collection Road Category Weighting factor Region A Region B Region C I WF A1 WF B1 WF C1 II WF A WF B WF C III WF A3 WF B3 WF C3 Road Category I II III In-use driving behaviors Region A Region B Region C Develop unified speed-acceleration distribution Acc. (km/h/s) combine the short trips Compare the short trip combination and the unified distribution chi-squared based analysis Other parameter comparison Acc. (km/h/s) Acc. (km/h/s) Common test cycle 7

8 .3. Data collection matrix WLTP-DHC--3e The following matrix is requirement for each in-use data collection CP, with consistency between weighting factors and collected data. Sub categorization is acceptable with consistency between weighting factors and collected data. Urban Rural Motorway Weekday Offpeak Onpeak Onpeak Week -end Weekday Offpeak Onpeak Week -end Weekday Offpeak Week -end LD Commercial Vehicle (LDCV) Passenger Car (PC) (*) In case of lack of statistical information, annual driving distance in red box can be acceptable for data analysis.

9 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of high cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High 9

10 3.1. Data processing In-use Driving Data Processing WLTP-DHC--3e Raw Data Filtering & Thinning (if necessary) Data conversion Convert into L/M/H Calculate the compensated WF (refer to Appendix) Gear shift analysis Divide into idling and short trip portions idling database Idling Duration Distribution Idling Average Duration short trip (ST) database Speed-Acceleration (Positive & Negative) Distribution ST Duration Distribution ST Average Speed Distribution ST Average Duration Others (refer to 3.5.) (*) Definition of short trip (ST) idling-1 ST-1 idling- ST- Up shift Down shift In-use data in each road type and in each region is processed separately. Raw data shall be shared within the DHC group. 1

11 3..1. L/M/H method WLTP-DHC--3e 1. Considering the threshold vehicle speed Consider threshold based on each countries traffic condition and driving characteristic Find the threshold that shows similar Speed- Acceleration distribution of each countries. Calculate the compensated WF Using Drive condition WF and total driving duration 3. Convert in-use data(u/r/m => L/M/H). Analyze speed-acceleration distribution and driving characteristics (L/M/H) 5. Generate the driving cycle in each phase 11

12 3... Consideration of threshold speed - 1 WLTP-DHC--3e <Method1> Based on similarity of speed-acceleration distribution The threshold of Low/Middle Vmax L/M = / 5 / / 7? and Ratio V< > % etc. The threshold of Middle/High Vmax M/H = / 9 / 1/ 11? and Ratio V<9 > 5% etc. Low (Vmax ) Low (Vmax 5) Low (Vmax ) Low (Vmax 7) χ :.39 χ ave :.37E-3 χ :.1 χ ave : 1.75E-3 χ :.9 χ ave : χ :.95 χ ave :.5E-3 Japan km/h Japan 5km/h Japan 7km/h Japan km/h Low(Vmax<km/h, ~km/h %) Japan WMTC Japan χ :.5 χ ave : 3.39E-3 χ : 1.55 χ ave :.59E-3 χ :. χ ave : χ : 3.9 χ ave :.1E-3 EU km/h EU 5km/h EU 7km/h EU km/h EU WMTC EU χ :.9 χ ave : 5.1E-3 χ : 1. χ ave :.3E-3 χ : 1. χ ave : χ : 1.9 χ ave :.59E-3 Korea km/h Korea 5km/h Korea 7km/h Korea km/h Korea WMTC Korea Σχ : 1.91 Sum: 1.E- Σχ :.9 Sum: 1.E- Σχ :.79 Sum: Σχ : 5.73 Sum: 1.5E- Average km/h Average 5km/h Average Average km/h 7km/h Average WMTC Average

13 3..3. Consideration of threshold speed - WLTP-DHC--3e <Method> Based on parameter value Road type Speed rage Average speed km/h JPN EU KOR Max- Min Relative positive acceleration m/s JPN EU KOR Max- Min Idling ratio JPN EU KOR Max- Min JPN EU KOR Max- Min JPN EU KOR Max- Min Urban % Average short trip duration s Average idling duration s Urban Low Rural Rural Middle Motorway Motorway High < < < Select the candidate threshold speed based on least discrepancy in each characteristic. 13

14 3... Consideration of threshold speed - 3 WLTP-DHC--3e <Method3> Based on maximum speed distribution Japan Total Frequency (%) Japan Urban Japan Rural Japan Motorw ay 5 /? / 9? Maximum speed (km/h) EU Total Frequency (%) Maximum speed (km/h) Korea Total Frequency (%) Frequency (%) 1 EU Urban EU Rural EU Motorw ay 5 / 11? Maximum speed (km/h) Frequency (%) 1 / 9? Maximum speed (km/h) Korea Urban Korea Rural Korea Motorw ay Frequency (%) Maximum speed (km/h) Maximum speed (km/h) After completion of all data acquisition, final threshold speed will be determined by taking into account of three methods. 1

15 3..5. Data conversion WLTP-DHC--3e Convert the each short trip data including the previous idling portion into new categories (Low/Middle/High) from original (Urban/Rural/Motorway) categories with the compensated WF (w ) criteria : maximum vehicle speed, speed frequency etc. Image Urban Rural Motorway Low Middle High The segments that composed of ST and IDLE move into L/M/H categories with the compensated WF. (*) Calculation formula of the compensated WF are shown in Appendix. 15

16 Develop the speed-acceleration distribution WLTP-DHC--3e Develop the speed-acceleration distribution in each region Japan EU Korea US India China Low Middle Average:.1 km/h Idling ratio 1. % Average: 3. km/h Idling ratio 1. % Average: 9. km/h Idling ratio 3.1 % Average: 13. km/h Idling ratio 39.1 % Average: 37.9 km/h Idling ratio 9. % Average: 75.7 km/h Idling ratio.3 % EU Low EU Middle EU High Japan Low Japan Middle Average: 11.7 km/h Idling ratio 3. % Average: 31.1 km/h Idling ratio 1.3 % Average: 59.1 km/h Idling ratio. % Korea Low Korea High Korea Middle High Japan High <Example>

17 3.3.. Analyze driving characteristics WLTP-DHC--3e To confirm the representativeness of the unified cycle, the following distributions and parameters will be analyzed. Distribution ST speed-acceleration distribution ST duration distribution ST average speed distribution ST maximum speed distribution ST length distribution ST cruise speed distribution ST speed * acceleration distribution Idling duration distribution Vehicle speed (km/h) V-A distribution Max. acceleration Speed distribution Max. speed Ave. speed Short trip duration Idling duration Parameter Average speed (km/h) Maximum Maximum Acceleration (km/h/s or m/s ) Maximum Deceleration (km/h/s or m/s ) Relative Positive Acceleration (m/s ) Average short trip duration (s) Average idling duration (s) Number of idling per kilometer (#/km) Number of idling per second (#/s) Time accelerating (%) Time decelerating (%) Time cruising (%) Time stop (%) 17

18 Develop the unified speed-acceleration distribution WLTP-DHC--3e Develop the unified speed-acceleration distribution ex.: speed-acceleration distribution in Low phase Region A Low speed-acceleration distribution in region A Region B Low speed-acceleration distribution in region B RW Low,A WF Low in region A RW Low,B WF Low in region B Unified Distribution Unified speed-acceleration distribution in Low phase RW = Regional Weight Unified distributions for the following parameters will be generated. Short trip duration distribution, Short trip average speed distribution, Idling duration distribution, others 1

19 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of high cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High 19

20 .1.1. Determination of the number of idle and short trip WLTP-DHC--3e Determine the test cycle duration < ex. WMTC: x 3phases, WHDC: 1, LA#:1371, NEDC: 11, JC: (sec) > Low cycle Middle cycle High cycle Time (T L ) Time (T M ) Time (T H ) Determine the number of idle and short trip in each phase Calculate the number in each phase (Low, Middle, High) number of short trip (N ST, i ) = drive cycle duration in each phase (T i ) - average idling duration average short trip duration + average idling duration number of idle (N I, i ) = number of short trip (N ST, i ) + 1 <example> T L = sec, average low short trip duration = sec, average low idling duration = sec, number of short trip (N ST,L ) = ( ) / ( + ) = 7.5 => 7 number of idling (N I,L ) = =

21 .1.. Determination of the idle and short trip duration WLTP-DHC--3e Determine the N I, i units of idling duration in each phase Generate the cumulative frequency graph based on idling data base Divide into N I, i equally in Y axis Select the average duration in each class N I, i units of idling duration ( ID 1, ID,.., ID NI, i ) in each phase are decided Cumulative frequency 1% N ID 1 ID ID N IDLE duration Determine the N ST, i units of short trip duration in each phase Generate the cumulative frequency graph based on short trip data base Divide into N i, ST equally in Y axis Select a average duration in each class respectively. if necessary, adjust the duration to match the target cycle duration Pick the candidate short trips which duration are STD 1, STD,.., STD NST, i Cumulative frequency 1% N STD 1 STD STD N ST duration 1

22 .1.3. Determination of the idle and short trip duration WLTP-DHC--3e Select the ST which duration is adjusted by the following formula (T n ) to match the target cycle duration. Compensate duration T N = STD N / ΣSTD i * T short Same adjustment for idle duration will be taken, if necessary. T 1 T T 3 T N T short STD 1 STD STD 3 STD N ID 1 ID ID 3 ID ID N+1 Cumulative frequency 1% N STD 1 STD STD N ST duration +T N T target (*) T N = STD N / ΣSTD i * T short

23 .1. Determination of the short trip combination WLTP-DHC--3e Determine the short trip combination in each phase Generate the speed-acceleration distribution in each combination from candidate short trips Compare with the unified distribution Select the short trip combination with the least χ value Check other distributions and parameters (refer to Appendix 1) Unified speed - acceleration distribution Acc. (km/h/s) Candidate short trips STD 1 STD STD N N STD1 N STD N STDN Generate the speed - acceleration distribution in each combination Comparison based on chi-squared analysis Acc. (km/h/s) Number of combinations = (N STD1 )*(N STD )* *(N STDN ) Acc. (km/h/s) the least χ value Acc. (km/h/s) 3

24 .1.5. Sample of the ST combination WLTP-DHC--3e (s) No. of STD Duration STD1 1sec STD 15sec STD3 1sec STD sec STD5 3sec STD sec 1 N Combinations Selected Short Trips speed-acceleration distribution Speed (km/h) 1 Acc. (km/h/s) 1 Acc. (km/h/s) Speed (km/h) 1 N-N-N-N-N-N This analysis will be done for each phase. 1 Acc. (km/h/s) Speed (km/h) 1

25 .1.. Selection of each ST duration WLTP-DHC--3e 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 potential STs in each ST duration Longer ST has more potential STs since it has bigger influence on chi-square value. Total number of combinations is less than 1 7~. Approximately 3 days on Xeon X59 (Quad core, 3.GHz) X 1 X X 3 X X 5 sec. Y sec N * X /Y N * X 5 /Y units N units 5

26 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of high cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High

27 ..1. Process of high-speed cycle development WLTP-DHC--3e 1. Determine the high-speed cycle duration (e.g. sec.). Determine the ST duration based on average ST duration and idling duration ratio of in-use data, the divide the ST into XX segments 5 segments and 1 cruise More than 5 segments and cruise Others <consider phases (High-1 / High-) cycle profile, if necessary > 3. Extract the driving data which meet each part s configuration from in-use STs.. Select the least chi-squared extracted driving data in each part, then combine the these data to develop the High-speed cycle. (note) if the complete in-use ST is less chi-squared value than combined High-speed cycle, this specific ST can be used for Highspeed cycle. 7

28 ... (Example) Divide into 5 parts of High-speed cyclewltp-dhc--3e Generate speed range and duration Divide into 3 speed range based on dividing frequency distribution Example: ~75 km/h, 75~9 km/h, 9 km/h~ Decide target duration in each range, then divide into two portions (take-off and slow-down) Example of ~75km/h: 3% => 17 sec => take-off part 1 sec,slow-down 1 sec % 3% 1% = sec. Japan High 3% 31% Speed range Idling ~75, 75~ 75~9, 9~75 9~ Frequency (%) Target duration Divide part Total 1 Adjust sec. ~ 75 km/h, 1 sec 75 ~ 9 km/h, 9 sec 9 ~ 9 km/h, 1 sec 9 ~ 75 km/h, 9 sec 75 ~ km/h, 1 sec (slow-down ) (take-off 1) (take-off ) (Cruise) (slow-down 1)

29 ..3. Extraction of driving data WLTP-DHC--3e Extract the driving data which meet each part s definition* from in-use ST. Sample definition <Take-off 1 part> speed range : ~ 75 km/h (with±.5km/h), duration : 1sec. Veh. speed 1 s ~75 km/h Veh. speed 1 s ~75 km/h Veh. speed Time Time Time ~75 75~9 9~9 75~ 9

30 ... Connection conditions WLTP-DHC--3e Connection conditions: Tolerance of the vehicle speed at connection point is ±.5 km/h example: 75 ±.5 km/h The vehicle speed at connection point is adjusted to average of connected two points. The vehicle speed of the end of first segment: 7.km/h The vehicle speed of the start of second segment: 75. km/h The vehicle speed of connected point will be 75. km/h Avoid the uncharacteristic connection OK: Acc. => Acc. or Cruise or Dec. => Dec. or Cruise Not OK: Acc. => Dec. or Dec. => Acc. End point Start point Acc. => OK Acc. Cruise => OK Dec. => NG 1st segment nd segment 3

31 ..5. Method to develop High-speed cycle WLTP-DHC--3e Candidate driving data (take-off1) (take-off) (Cruise) (slow-down1) (slow-down) combined Reference database High 9< Least chi-squared distribution Seek the combination cycle with least chi-square value compared with unified cycle 31

32 Table of contents WLTP-DHC--3e 1. Purpose. Outline of Test cycle development.1. Overall process.. Basic concept.3. Data collection matrix 3. Data processing 3.1. Data processing 3.. Data conversion (U/R/M to L/M/H*) 3.3. Develop the unified distributions and characteristics. Test cycle development.1. Process of Low/Middle cycle development.. Process of high cycle development Appendix. Compensated weighting factor (*) U/R/M: Urban/Rural/Motorway, L/M/H: Low/Middle/High 3

33 Compensated WF - 1 WLTP-DHC--3e The collected data duration urban T U road vehicle congestion on peak weekend on peak PC T U,PC off peak LCV T U,LCV off peak weekend on peak rural T R weekend on peak PC T R,PC off peak LCV T R,LCV off peak weekend on peak motorway T M weekend on peak PC T M,PC off peak LCV T M,LCV off peak weekend T U,PC,ON T U,PC,OFF T U,PC,E T U,LCV,ON T U,LCV,OFF T U,LCV,E T R,PC,ON T R,PC,OFF T R,PC,E T R,LCV,ON T R,LCV,OFF T R,LCV,E T M,PC,ON T M,PC,OFF T M,PC,E T M,LCV,ON T M,LCV,OFF T M,LCV,E Weighting factor matrix road vehicle congestion on peak PC w U,PC off peak urban w U weekend on peak LCV w U,LCV off peak weekend on peak PC w R,PC off peak rural w R weekend on peak LCV w R,LCV off peak weekend on peak PC w M,PC off peak motorway w M weekend on peak LCV w M,LCV off peak weekend sum 1 sum 1 sum 1 w U,PC,ON w U,PC,OFF w U,PC,E w U,LCV,ON w U,LCV,OFF w U,LCV,E w R,PC,ON w R,PC,OFF w R,PC,E w R,LCV,ON w R,LCV,OFF w R,LCV,E w M,PC,ON w M,PC,OFF w M,PC,E w M,LCV,ON w M,LCV,OFF w M,LCV,E It is expected that the collected data volume in each matrix doesn t match the weighting factor obtained based on vehicle statistical information. 33

34 Compensated WF - WLTP-DHC--3e Need to compensate the weighting factor of each matrix since the specific short trip is possible to move into different matrix. (1) Calculate the compensated weighting factor (w i ) urban w U rural w R motorway w M road vehicle congestion on peak w U,PC,ON ' weekend w U,PC,E ' on peak w U,LCV,ON ' PC w U,PC off peak w U,PC,OFF ' LCV w U,LCV off peak w U,LCV,OFF ' weekend w U,LCV,E ' on peak w R,PC,ON ' weekend w R,PC,E ' on peak w R,LCV,ON ' PC w R,PC off peak w R,PC,OFF ' LCV w R,LCV off peak w R,LCV,OFF ' weekend w R,LCV,E ' on peak w M,PC,ON ' weekend w M,PC,E ' on peak w M,LCV,ON ' PC w M,PC off peak w M,PC,OFF ' LCV w M,LCV off peak w M,LCV,OFF ' weekend w M,LCV,E ' sum 1 sum 1 sum 1 W W U,PC,ON = U,PC,ON A TU,PC,ON U,PC W W U,PC,OFF = U,PC,OFF A TU,PC,OFF U,PC W U,PC,E = where W U,PC,E T U,PC,E W U,PC,ON T U,PC,ON A U,PC A U,PC = W U,PC,ON + W U,PC,OFF + W U,PC,E + W U,PC,OFF T U,PC,OFF W U,PC,E T U,PC,E Same equation will be applied to others + 3

35 Compensated WF - 3 WLTP-DHC--3e The collected data was converted into new categories. New weighting factors(w L, w M, w H ) are calculated as follows. w w w L M H = = = i i i ( w ) L,i TL,i i ( w T ) + ( w T ) + ( w T ) L,i ( w ) M,i TM,i i ( w ) ( ) ( ) L,i TL,i + w M,i TM,i + w H,i TH,i i i ( w ) H,i TH,i i ( w T ) + ( w T ) + ( w T ) L,i L,i L,i i i M,i M,i M,i M,i i i H,i H,i H,i H,i This process will be done in each data collection CPs. 35

WLTP DHC subgroup. Draft methodology to develop WLTP drive cycle

WLTP DHC subgroup. Draft methodology to develop WLTP drive cycle WLTP DHC subgroup Date 30/10/09 Title Working paper number Draft methodology to develop WLTP drive cycle WLTP-DHC-02-05 1.0. Introduction This paper sets out the methodology that will be used to generate