1. Comparing EMROAD and the ACEA RDE Evaluation Tool
Pierre Bonnel
Martin Weiss
Joint Research Centre (JRC)
IES - Institute for Energy and Transport
Ispra – Italy

2. Introduction
Purpose of both tools: Characterizing on-road emission measurements
Principle problem: On-road emission tests cover longer distances than the NEDC
Suitable approaches to characterize on-road emissions:
- averaging the entire test
- averaging sub-sections (e.g., averaging windows)
Need to develop:
- algorithms to determine length and sequence of sub-sections
- methods to characterize average emissions

3. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool

4. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Time

5. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Time

6. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Time

7. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Δt = 1s
Time

8. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2 …
Δt = 1s
Time

9. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2 …
Δt = 1s
Time

10. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2 …
Δt = 1s
Time

11. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Cum. CO2 …
Δt = 1s
Time
Time

12. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Cum. CO2 …
Δt = 1s
Δt = 1s …
Time
Time

13. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Cum. CO2 …
Δt = 1s
Δt = 1s …
Time
Time

14. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Cum. CO2 …
Δt = 1s
Δt = 1s …
Time
Time

15. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Cum. CO2 …
Δt = 1s
Δt = 1s …
Time
Time

16. Methodology Different approaches to calculate averaging windows
EMROAD ACEA-RDE Evaluation Tool
Cum. CO2
Cum. CO2 …
Δt = 1s
Δt = 1s …
Time
Time
EMROAD may exclude some cold-start emissions
ACEA-RDE Evaluation Tool includes all emission measurements
Number of windows may differ slightly among the two tools
Differences in percentiles can be expected to be negligible

17. Methodology Characterizing averaging window emissions
Approach taken from the heavy-duty vehicle regulation 582/2011
Limits are defined as brake-specific emissions
- Both parameters provide an indication about the deviation of in-use
emissions from applicable emission limits

18. Methodology
Light-duty vehicles – distance-specific emissions limit:

19. Methodology
DR vs. CF:
- Substituting mass of emissions by the product of distance-specific emissions and window distance

20. Comparison of results
Recent PEMS tests of an Euro 6 vehicle (155g CO2/km)
1 test on each Route 1-3: rural-motorway, rural-urban, rural-uphill/downhill
EMROAD
ACEA Tool
Test
NOX in g/km
Milano_
0.134
Varese_
0.095
SCM_
0.276
Test
No. of windows
EMROAD
ACEA Tool
Deviation in %
Milano_
6917
6913
-0.1
Varese_
5427
5414
-0.2
SCM_
5531
5524

21. Comparison of results
Averaging window NOX emissions

22. Comparison of results
Averaging window NOX emissions

23. Comparison of results
Averaging window NOX emissions – Comparison Deviation Ratio
 DR
EMROAD
ACEA Tool
Deviation EMROAD-ACEA Tool in %
Deviation EMROAD-
ACEA in %
90% percentile
100% percentile
90%
percentile
100%
Milano_
2.55
4.18
-0.1
0.1
Varese_
2.43
2.42
2.90
2.89
0.0
0.5
SCM_
6.39
9.56
9.55
Averaging window NOX emissions – Comparison Conformity Factor
 CF
EMROAD
ACEA Tool
Deviation EMROAD-ACEA Tool in %
Deviation EMROAD-
ACEA Tool in %
90% percentile
100% percentile
90%
percentile
100%
Milano_
2.57
2.58
2.98
2.99
-0.5
-0.2
Varese_
1.97
2.09
2.10
-0.3
-0.6
SCM_
5.26
5.28
5.41
5.43
-0.4

24. Conclusions Both tools yield similar but not identical results
Deviations are negligible in the context of the RDE-LDV working group
ACEA RDE Evaluation Tool allows easy installation and straight forward use but is limited to the analysis of NOX emissions
EMROAD is more complex and requires training prior to use
Both tools are fit for use in the RDE-LDV working group
Methodological choices on the algorithm for determining the averaging windows and the characterization of average emissions should be discussed within the RDE-LDV working group

25. Thank you! Joint Research Centre (JRC)
IET - Institute for Energy and Transport
Ispra – Italy
Pierre Bonnel
Martin Weiss