Evaluating the Real-Driving Emissions of Light-Duty Vehicles: A Challenge for the European Emissions Legislation

Authors

Dr. T. G. Vlachos, Dr. P. Bonnel, Dr. M. Weiss, European Commission, Joint Research Centre (JRC) - Institute for Energy and Transport, Ispra

Year

2015

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 783

Summary

To strengthen the European emissions legislation, the European Commission has established a Real-Driving Emissions (RDE) test procedure for complementing the current “Type I” type-approval test of light-duty vehicles. Key to the effectiveness of the RDE test procedure is a robust evaluation of on-road operating conditions and pollutant emissions as measured with Portable Emissions Measurement Systems (PEMS). We provide a detailed description of the two data evaluation methods that are implemented in the RDE procedure. The moving averaging windows method divides the test into sub-sections (windows) and uses the distance-specific average of carbon dioxide (CO2) emissions of each window to assess the normality of operating conditions. The power binning method categorizes the instantaneous on-road emissions into power bins based on the corresponding power at the wheels. The normality of the resulting power distribution is established by comparison with a standardized wheel power frequency distribution. Both methods include criteria to ensure that a realized test covers the dynamic boundary conditions set by the RDE test procedure. Based on data obtained from Euro 6 vehicles driven with various driving styles, we discuss the ability of the methods to normalize operating conditions and calculate the RDE emissions result. We conclude by presenting an outlook on future extensions of the RDE test procedure and the two data evaluation methods.