LDV Real Driving Emissions: - Evaluation of PEMS results based on the Moving Averaging Window and a CO2 Severity Indicator - Update on the concept - Next Steps - Data evaluation Tool (EMROAD) - Brussels 11th of April 2013 Pierre Bonnel - European Commission DG - Joint Research Centre (JRC) - IET - Institute for Energy and Transport
Evaluation principles Description of the concept Data evaluation tool Next steps
Data evaluation principles Segmenting the data, representing different conditions of the emissions control system Averaging emissions data Defining normal driving using a composite indicator (Distance-specific CO2) Calculating the sensitivity of the emissions for different driving conditions (currently speed based, tentative to show the sensitivity of the emissions control performance with respect to vehicle speed)
Overview of evaluation steps Step 1. Mark cold start and DPF regeneration Step 2. On the remaining data(*): Moving averaging window (MAW) Using a reference quantity Multiples or dividers of the vehicle CO2 [kg] on the WLTP used as baseline. Metrics in the windows g/km as baseline. Step 3. Binning of MAW results Speed bins (Low, Medium, High, Extra High) Vehicle CO2 characteristic curve defining normal, severe, soft and extreme driving Maximum idling percentage in the windows (baseline 10%) (*) Excluding the data marked at step 1
Marking cold start & DPF Regen 160.00 2.00 140.00 Resulting data for MAW analysis 1.50 120.00 1.00 100.00 0.50 80.00 60.00 Cold Start DPF Regen 0.00-0.50-1.00 Vehicle Speed [km/h] MAW ANALYSIS YES [1] / NO [0] DPF REGEN YES / NO COLD START YES / NO 40.00-1.50 20.00-2.00 0.00-2.50 0 1000 2000 3000 4000 5000 6000 7000 8000
Example: MAW NOx vs. MAW CO2 300 VEH_SPEED MAW_AVG_SPEED MAW_CO2 VEH_SPEED MAW_NOx 250 200 150 100 50 0 0 1000 2000 3000 4000 5000 6000 7000 8000 9000 Time [s]
Vehicle CO2 characteristic curve The vehicle CO2 characteristic curve is used to define normal driving Current concept: Vehicle-specific curve (CO2 [g/km]) versus (Average Speed [km/h]) Tolerances around the curve define, at a given average speed: Normal driving (CO2 Curve - T1 <= MAW CO2 <= CO2 Curve + T1) Severe driving (CO2 Curve + T1 < MAW CO2 <= CO2 Curve + T2) Soft driving (CO2 Curve T2 <= MAW CO2 < CO2 Curve T1) Extreme driving (MAW CO2 > CO2 Curve + T2) or MAW CO2 < CO2 Curve - T2) PRELIMINARY - FOR INFORMATION ONLY - MARCH 2013
MAW CO2 Emissions [g/km] Vehicle CO2 characteristic curve Example: Option 3 Composite Curve Tolerance 1 = 25% - Tolerance 2 = 50% 350 300 250 200 150 100 MAW_CO2 T_CURVE T_CURVE_L1 T_CURVE_H1 WHTC_CO2 T_CURVE_L2 T_CURVE_H2 50 0 0 20 40 60 80 100 120 140 160 MAW Average Speed [km/h]
Vehicle CO2 Characteristic curve & Tolerances Normal driving: around the curve (+/- TOLERANCE 1) Severe driving: above the curve (between TOLERANCE 1 and TOLERANCE 2) Soft driving: below the curve (between TOLERANCE 1 and TOLERANCE 2) Extreme driving... All the rest
Buidling the vehicle CO2 characteristic curve Current concept: curve fitting, using the vehicle CO2 emissions on the phases of the type approval cycle (WLTP) Other concepts?
Vehicle CO2 characteristic curve Example: Option 3 Composite Curve Tolerance 1 = 25% - Tolerance 2 = 50% - 2 Test Sites, 3 routes each T_CURVE_L1 T_CURVE_H1 WHTC_CO2 T_CURVE_L2 T_CURVE_H2 SITE 1 - ROUTE 3 SITE 1 - ROUTE 1 SITE 1 - ROUTE 2 SITE 2 - ROUTE 1 SITE 2 - ROUTE 2 SITE 2 - ROUTE 3 MAW CO2 Emissions [g/km] T_CURVE 0 20 40 60 80 100 MAW Average Speed [km/h] 120 140 160 180
Next steps Verification of the CO2 indicator: to which operating conditions correspond the high CO2 values? This shall be documented from the different tests currently conducted on the different vehicles. Method settings Sensitivity studies to be conducted to determine the appropriate combination for the: Level of averaging Curve design Tolerances Requirements for the route composition A priori, per time of distance share A posteriori (realized), through the number of windows in the bins (e.g normal, low speed)
DATA EVALUATION TOOL - EMROAD
Status & How to get help Current version as BETA, first non-beta release within end of April 2013 Always check for latest version on CIRCABC Try to use the software on your own, using the available instructions (Users guide and release notes, also available from CIRCABC) In case of bugs or crash, please provide a short report by email or - better - provide JRC with the EMROAD template and the corresponding raw (PEMS) data file. Should you have short questions on the calculation principles/algorithm, send them by e-mail to JRC.
Evaluation Tool: EMROAD - Interface PRELIMINARY - FOR INFORMATION ONLY - MARCH 2013
Quick Start Installation of EMROAD as Excell Add-In (Refer to users guide or release notes) and from the EMROAD menu Select the PEMS file Input the Calculation Settings paying attention to: The type of instrument file The presence of parameters required for the exclusions (Coolant temperature, DPF regeneration) and/or the calculations The MAW reference quantity The vehicle CO2 characteristic curve and the tolerances Run One-step Calculation RDE results reported in the RDE PASS-FAIL worksheet
In the tool... Concept: Curve fitting WLTP values: Mathematical options 1, 2 and 3: The curve is build using the vehicle CO2 values [g/km] over the WLTP phases. Option 1: Polynomial fit Order 3 Option 2: Composite, i.e. Polynomial fit Order 3 and constant ranges in the Extra Low Speed and Extra High Speed speed ranges Option 3: Composite, i.e. Polynomial fit Order 3 and linear tangent in the Extra Low Speed and Extra High Speed speed ranges Other concepts: Option 4: Custom curve (Input of CO2 [g/km] vs. Speed [km/h]) curve
Curve concept: WHTC CO2 fitting Input: CO2 values in [g/km] over the Low, Medium, High and Extra High speed phases Average speeds in [km/h] of the Low, Medium, High and Extra High speed phases (Fixed values Resp. 19, 40, 57, 92) Average speed range (currently 10 to 140 km/h) Current options Option 1: Polynomial fit Order 3 Option 2: Polynomial fit Order 3 / Constant CO2 below 19 and above 92 km/h, equal respectively to the low and extra high speed CO2 values in g/km Option 3: Polynomial fit Order 3 / Linear tangent to the curve below 19 and above 92 km/h
Many thanks for your attention!!! For further information, please contact: Pierre Bonnel EC JRC pierre.bonnel@jrc.ec.europa.eu