Working document

RDE-LDV boundary conditions – Draft 1

JRC, 31 July 2012

1. Objective

This working document providesan overview of parameters that are relevant for defining the boundary conditions of the RDE-LDV test procedure. The document thereby sets the stage for defining in the next stepthe actual values and value ranges of the boundary conditions.Stakeholders are asked to provide comments and suggestions on the parameters listed below until 5 September 2012 (Email to: and ).

2. Definition

Boundary conditions are defined here as parameters or elements used for characterizing the permissible environmental and driving conditions under the RDE-LDV test procedure. The boundary conditions of this procedure shall reflect as far as possible the range of operating conditions of light-duty vehicles in the European Union.

3. Boundary conditions - constituting elements

3.1Environmental conditions

(i)Ambienttemperature, humidity, and altitude

-Principle data source:

  • TNO (2006): Evaluation of the suitability to European conditions of the WNTE control zone concept as set out in the OCE GTR. TNO Report 06.OR.PT.047/HJD
  • UNECE Regulation 83 – Revision 4 – Appendix 6 (Requirements for vehicles that use a reagent for the exhaust after-treatment system)
  • EU regulation for heavy-duty engines (Regulation 582/2011, Annex II)

3.2Driving conditions

(i)Definition of Low, Medium, and High Speed driving, including maximum speeds for each category

(ii)Shares of Low, Medium and High Speed driving

  • Average EU values in %
  • Ranges shall be developed
  • Principle data source: European part of the WLTP database

(iii)Average speeds of Low, Medium and High Speed driving

  • Average EU values in km/h, calculated excluding idling
  • Principle data source: European part of the WLTP database

(iv)Idling percentages for Low, Medium and High Speed driving

  • Definition of idling (e.g., vehicle speed <5 km/h)
  • Analysis of idling and non-idling values separately and/or definition of maximum permissible idling shares in %
  • Principle data source: European part of the WLTP database

(iv)Driving dynamics (vehicle accelerations)

  • 1. Analysis by short trips: RPA[1] versus speed
  • 2. Instantaneous accelerations
  • Principle data source: European part of the WLTP database

(v)Road grade

  • Distribution of average road grades of European roads (averaging distance to be determined)
  • Principle data source: GIS(?)

3.3Procedure design elements

Procedure design elements were initially part of the boundary conditions table; they will be addressed later during the development of the RDE-LDV procedure.

  • Total test duration (RCG, PEMS)
  • Number of speed phases (RCG, PEMS trip composition)
  • Rules for excluding trips, parts of trips, or individual data points for which driving pattern are outside the predefined boundary conditions (RCG, PEMS)
  • Decision on the analysis of idling and non-idling phases; weighing
  • The potential application of dynamic correction factors for emissions based onparameters of driving dynamics that are strongly correlated with NOx emissions (e.g., RPA of the entire trip, some sub-trip or a moving window) instead of applying strict global boundary conditions (i.e. the measured emissions are corrected according to the underlying driving dynamics before comparing them to regulatory emission limits)
  • Total number of short trips (RCG)
  • Initial source of short trips (RCG)
  • Number of short trips in the data base (RCG)
  • Gear shifting strategy (RCG)
  • Others

3.4Elements not applicable in this context

Data evaluation method; Family building; Day time/traffic volume

1

[1] Different definitions will be used