LDV Real Driving Emissions: - Assessment of MAW evaluation method: Sensitivity study - RDE Task Force Meeting, 28th November 2013, Brussels Theodoros Vlachos, Martin Weiss, Pierre Bonnel - European Commission DG - Joint Research Centre (JRC) - IET - Institute for Energy and Transport

Objectives Proposal of an analysis for data evaluation EMROAD v5.7 V002 NOx Emissions: Statistical Analysis (Weighted Emissions) W_NOT==0 Main results obtained: weighted emissions calculated on the basis of indicators compared to the average calculated on total trips for vehicle 2 EMROAD v5.7

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Conclusions

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Conclusions

Assessment criteria (1/1) ROBUSTNESS: Ability to evaluate testing conditions (trip) Data coverage Ability to assess RDE performance Ability to assess RDE performance under specific testing conditions Robustness against uncertainties of data acquisition and data evaluation Technological neutrality PRACTICABILITY: PEMS testing effort Availability and accuracy/reliability of input parameters Simplicity of calculation steps Possibility for independent RDE testing Flexibility to be adapted to future emissions legislation

Outline Assessment Criteria Proposed analysis per assessment criterion Results Conclusions

Robustness Analysis (1/2) Analysis and results required from the different tools: Assessment Criterion Analysis ROBUSTNESS A. Ability to evaluate testing conditions (trip) Generic trip characteristics (all methods) B. Data coverage Results from indicators (method specific or not) C. Ability to assess RDE performance Total emissions [g/km] with and without data exclusion for all tests: I. Taking into account all driving conditions (normal, severe, soft) II. For normal driving only D. Ability to assess RDE performance under specific testing conditions For normal driving only (for all tests): I. Average emissions [g/km] for U/R/M, separately, with and without data exclusion II. Distance weighted emissions [g/km] with and without data exclusion

Robustness Analysis (2/2) Analysis and results required from the different tools: Assessment Criterion Analysis ROBUSTNESS E. Robustness against uncertainties of data acquisition and data evaluation Case studies Data uncertainties: Sensitivity studies Robustness of data evaluation 1: Performance of the RDE method for specific testing situations Roundtrip clockwise and counterclockwise driving Aggressive versus soft or normal driving style Aggressive driving during part of a test Robustness of data evaluation 2: Sensitivity of the RDE method to their design parameters F. Technology neutrality Description of the principles envisaged to adapt the methods to hybrid powertrains and alternative fuels (Discussion) Implications in terms of testing (Parameters and quality required) (Possibly) case studies with results (as for criteria A, B, C, D)

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Robustness against uncertainties of data evaluation Conclusions We provide a series of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Robustness against uncertainties of data evaluation Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Testing Conditions MAW were categorized in 3 different testing conditions: Normal driving (MAW within Normal Driving Upper & Lower Bounds); Severe driving (MAW within Severe & Normal Driving Upper Bounds); Soft driving (MAW within Severe & Normal Driving Lower Bounds). Several Driving – Upper Bound Vehicle CO2 Characteristic Curve corrected for on-road Sever Testing Conditions Normal Driving – Upper Bound Normal Testing Conditions Normal Driving – Lower Bound Soft Testing Conditions Several Driving – Lower Bound Vehicle CO2 Characteristic Curve vs. Vehicle Speed (EMROAD v5.7) A tolerance of 25% respect vehicle CO2 characteristic curve was used for defining “Normal driving region” Categorization of the severity is based on MAW CO2 [g/km] with respect to vehicle CO2 characteristic curve. EMROAD v5.7

Vehicle Speed Binning MAW were categorized in 3 different vehicle speed bins: Urban driving (U) (0≤ Veh.SpeedMAW [km/h] >45); Rural driving (R)(45≤ Veh.SpeedMAW [km/h] ≥80); Motorway driving (M) (80≤ Veh.SpeedMAW [km/h]). Urban Rural Motorway Sever Testing Conditions Vehicle CO2 Characteristic Curve corrected for on-road Normal Testing Conditions Soft Testing Conditions Vehicle CO2 Characteristic Curve vs. Veh. Speed (EMROAD v5.7) EMROAD v5.7

Indicator for trip validation Validation based on trip portion within Normal Driving Conditions. A “sufficient number (share)” of MAW is needed for all vehicle speed bins: U+R+M. Sufficient Number (Share) of MAW: percentage of MAW within Urban, Rural and Motorway bins respect to total number of Normal MAW. A target of 10% of MAW was adopted as “sufficient number (share)” of windows. SEVERITY CATEGORY ALL DRIVING NORMAL DRIVING Urban Rural Motorway All MAW # 1319 1785 2609 5713 1618 1870 4807 MAWdriving conditions [%] 23.08 31.24 45.67 100 27.44 33.66 38.90 This metric defines the contribution of U/R/M in Normal driving testing. 1319 5713 =23.08 1870 4807 =38.90

Indicator for trip validation Validation based on trip portion within Normal Driving Conditions. A “sufficient number (share)” of MAW is needed for all vehicle speed bins: U+R+M. Sufficient Number (Share) of MAW: percentage of MAW within Urban, Rural and Motorway bins respect to total number of Normal MAW. Weight factor of 0.33 was used for Urban, Rural and Motorway vehicle speed bins. A target of 10% of MAW was adopted as “sufficient number (share)” of windows. V002 NOx Emissions: Statistical Analysis (Weighted Emissions) W_NOT==0 EMROAD v5.7

Data Coverage (V002) (1/1) Vehicle CO2 Characteristic Curve and MAW Share vs. Vehicle Speed: Vehicle CO2 Characteristic Curve vs. Veh. Speed Share of Normal MAW Besides n-WLTC, SCM and R#3 routes do not show a sufficient number of MAW during motorway => NOT VALID trips (see next slides) => to be COMPLEMENTED EMROAD v5.7

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Routes Comparison Driving style Comparison (same Route) Robustness against uncertainties of data evaluation Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Routes Comparison Driving style Comparison (same Route) Robustness against uncertainties of data evaluation Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Routes Comparison (V002) (1/1) Weighted NOx emissions vs. Routes: Share of Normal MAW V002 NOx Emissions: Statistical Analysis (Weighted Emissions) W_NOT==0 No valid routes: n-WLTC, SCM, R#3. Tests should/could be complemented. Open issues: driving routes design (e.g. vehicle speed dynamics, U/R/M shares….) EMROAD v5.7

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Routes Comparison Driving style Comparison (same Route) Robustness against uncertainties of data evaluation Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Driving Style Comp. (V002) (1/1) Vehicle CO2 Char. Curve, MAW Shares and weighted emissions vs. Vehicle Speed: Share of Normal MAW NOx Emissions: Statistical Analysis (Weighted Emissions) W_NOT==0 Routes characteristics (see previous slides) and vehicle dynamics could have a significant impact on emissions. Vehicle CO2 Characteristic Curve vs. Veh. Speed Significant changes in both MAW distribution across vehicle CO2 char. curve and NOx weighted emissions. EMROAD v5.7

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Robustness against uncertainties of data evaluation Repeatability Check Sensitivity on data exclusion Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Robustness against uncertainties of data evaluation Repeatability Check Sensitivity on data exclusion Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Repeatability Check (V002) (1/1) Vehicle CO2 Char. Curve vs. Veh. Speed: NOx Emissions: Statistical Analysis (Weighted Emissions) W_NOT==0 Share of Normal MAW A maximum deviation among results obtained by tests on the same vehicle, route and driving style should be taken into account. Vehicle CO2 Characteristic Curve vs. Veh. Speed A variation of 15% among trips was observed as far as NOx emissions is concerned. A variation of 17% among trips was observed as far as MAW is concerned. EMROAD v5.7

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Data coverage Ability to assess RDE performance Robustness against uncertainties of data evaluation Repeatability Check Sensitivity on data exclusion Conclusions We provide a sereis of presentations with the totality of the results for the three vehicles, but for sake of brevity I will focus on soe of these

Data Exclusion (V001) (1/1) Vehicle CO2 Char. Curve vs. Veh. Speed: NOx Emissions: Statistical Analysis (Weighted Emissions) W_NOT==0 The application of exclusion criteria should be applied carefully. A detailed definition of how should be applied is needed (periodic regeneration effects, cold start, idling…) Vehicle CO2 Characteristic Curve vs. Veh. Speed Specific emissions can detect differences on emission levels. CO2 specific emissions seem to be less sensitive. Idling exclusion could be significant in case of MAW results. EMROAD v5.7

Outline Assessment Criteria Summary of analysis to be conducted per criterion Results Conclusions

Conclusions Assessment Criterion Analysis Effects ROBUSTNESS B. Data coverage Indicators adoption Validate/invalidate trips Complementing invalidate trips B and C. Ability to assess RDE performance Total emissions [g/km], average emissions for U/R/M, distance weighted emissions with and without data exclusion for all tests. Route design Vehicle dynamics E. Robustness against uncertainties of data acquisition and data evaluation Case studies (repeatability check) Definition of a tollerance for repeatability check. Driving style effects Vehicle dynamics should be taken into acount.

For further information, please contact: Theodoros Vlachos – EC JRC – theodoros.vlachos@jrc.ec.europa.eu Pierre Bonnel – EC JRC – pierre.bonnel@jrc.ec.europa.eu

LDV Real Driving Emissions: - Assessment of MAW evaluation method: Sensitivity study - RDE Task Force Meeting, 28th November 2013, Brussels Theodoros Vlachos, Martin Weiss, Pierre Bonnel - European Commission DG - Joint Research Centre (JRC) - IET - Institute for Energy and Transport