EU6d – Analysis of Boundary Conditions and Evaluation of the Impact on Emissions using the Example of the Advanced Diesel Powertrain

Authors

Dr.-Ing. A. Kufferath, Dipl.-Ing. D. Naber, Dr.-Ing. M. Krüger,
Robert Bosch GmbH, Stuttgart; Ao. Univ.-Prof. Dr. S. Hausberger, Dipl.-Ing. S. Lipp, Graz University of Technology; Dipl.-Ing. H. Steven, HS Data Analysis and Consultancy, Heinsberg

Year

2019

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 811

Summary

EU6d, the first stage of the regulatory package, has become effective in Europe in September 2017; under this regulation, limits on nitrogen-oxide and particulate emissions of new car types have to be met under the regulation’s real driving and ambient conditions. The second stage will enter into effect on 1 January 2020. The leeway provided by EU6d regarding the design of the test run and the boundary conditions that may prevail during the test run require a robust solution to be established for the emissions produced by the powertrain under all relevant operating conditions. The boundary conditions for test runs compliant with EU6d are defined by 29 parameters and were established on the basis of a comprehensive collection of real-driving data and statistical considerations. The aim of the regulation was to represent at least 95% of the driving conditions encountered in Europe including the resulting emissions. Driving conditions rendering a test invalid often represent conditions which are rarely encountered during driving or are derived from the aim of the regulation of combining as many driving states as possible in single measurement runs. The procedure that was followed to define the boundary conditions is described below.
Analyses based upon the Robert Bosch GmbH test vehicle show how NO_x emissions can be further reduced in a robust manner even under demanding driving and ambient conditions. In this context, the optimum interaction between the combustion engine and the exhaust-gas after-treatment system plays an essential role. The results obtained will also reveal to what extent the driving conditions and the resulting emissions are covered by the regulation. Finally, this paper will confirm that the existing definition of the boundary conditions and emission limits of EU6d represent a true reflection of driving conditions. Hence EU6d will contribute to a significant improvement of air quality in European cities.