Name: implementation of portable emissions measurement systems (pems) for the real-driving emissions (rde) regulation in europe
Uploaded: 2016-12-04T14:00:00
Duration: 9 min 34 s
Description: Watch this Scientific Journal Video about Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe at JoVE.com

The authors would like to thank Sensors Inc. for providing a PEMS for conducting an inter-laboratory exercise.

<ol>
	<li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Regulation No 83 on uniform provisions concerning the approval of vehicles with regard to the emission of pollutants according to engine fuel requirements, Addendum 82: Regulation No 83, Revision 4. , (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+No.+715/2007+of+the+European+Parliament+and+of+the+Council+of+20+June+2007on+type-approval+of+motor+vehicles+with+respect+to+emissions+from+light+passenger+and+commercial+vehicles+(Euro+5+and+Euro+6)+and+on+access+to+vehicle+repair+and+maintenance+information,+European+Commission+(EC).">Regulation No. 715/2007 of the European Parliament and of the Council of 20 June 2007on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, European Commission (EC).</a> Official J. European Union. L 171, 1-16 (2007).</li><li>Tietge, U., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> From laboratory to road: a 2015 update of official and "real-world" fuel consumption and CO2 values for passenger cars in Europe. ICCT white paper. , (2015).</li><li>Weiss, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On-road+emissions+of+light-duty+vehicles+in+Europe.">On-road emissions of light-duty vehicles in Europe.</a> Environ. Sci. Technol. 45, 8575-8581 (2011).</li><li>. Determination of PEMS measurement allowances for gaseous emissions regulated under the heavy-duty diesel engine in-use testing program. Revised Final report Available from: <a target="_blank" href="https://www.regulations.gov/document?D=EPA-HQ-OAR-2004-0072-0085">https://www.regulations.gov/document?D=EPA-HQ-OAR-2004-0072-0085</a> (2008)</li><li>Vlachos, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-use+emissions+testing+with+Portable+Emissions+Measurement+Systems+(PEMS)+in+the+current+and+future+European+vehicle+emissions+legislation:+Overview,+underlying+principles+and+expected+benefits.">In-use emissions testing with Portable Emissions Measurement Systems (PEMS) in the current and future European vehicle emissions legislation: Overview, underlying principles and expected benefits.</a> SAE Int. J. Commer. Veh. 7 (1), 199-215 (2014).</li><li>Vlachos, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluating+vehicles+real-driving+emissions+performance:+a+challenge+for+the+emissions+control+legislation.">Evaluating vehicles real-driving emissions performance: a challenge for the emissions control legislation.</a> VDI Research Reports. , (2015).</li><li>Hausberger, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experiences+with+current+RDE+legislation.">Experiences with current RDE legislation.</a> , (2015).</li><li>Demuynck, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Euro+6+Vehicles'+RDE-PEMS+Data+Analysis+with+EMROAD+and+CLEAR.">Euro 6 Vehicles' RDE-PEMS Data Analysis with EMROAD and CLEAR.</a> , (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commission+Regulation+2016/427.+Amending+Regulation+(EC)+No+692/2008+as+regards+emissions+from+light+passenger+and+commercial+vehicles+(Euro+6)).+Annex+IIIA+of+the+Commission+Regulation+(EC)+No.+692/2008+(2016).+Verifying+Real+Driving+Emissions.">Commission Regulation 2016/427. Amending Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6)). Annex IIIA of the Commission Regulation (EC) No. 692/2008 (2016). Verifying Real Driving Emissions.</a> Official J. European Union. L 82, 1-97 (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commission+Regulation+2016/646.+Amending+Regulation+(EC)+No+692/2008+as+regards+emissions+from+light+passenger+and+commercial+vehicles+(Euro+6).+Annex+IIIA+of+the+Commission+Regulation+(EC)+No.+692/2008+(2016).+Verifying+Real+Driving+Emissions.">Commission Regulation 2016/646. Amending Regulation (EC) No 692/2008 as regards emissions from light passenger and commercial vehicles (Euro 6). Annex IIIA of the Commission Regulation (EC) No. 692/2008 (2016). Verifying Real Driving Emissions.</a> Official J. European Union. L 109, 1-22 (2016).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commission+Regulation+(EC)+No.+692/2008+of+18+July+2008+implementing+and+amending+Regulation+(EC)+No+715/2007+of+the+European+Parliament+and+of+the+Council+on+type-approval+of+motor+vehicles+with+respect+to+emissions+from+light+passenger+and+commercial+vehicles+(Euro+5+and+Euro+6)+and+on+access+to+vehicle+repair+and+maintenance+information,+European+Commission+(EC).">Commission Regulation (EC) No. 692/2008 of 18 July 2008 implementing and amending Regulation (EC) No 715/2007 of the European Parliament and of the Council on type-approval of motor vehicles with respect to emissions from light passenger and commercial vehicles (Euro 5 and Euro 6) and on access to vehicle repair and maintenance information, European Commission (EC).</a> Official J. European Union. L 199, 1-135 (2008).</li><li>. On-road determination of average Dutch driving behaviour for vehicle emissions. TNO Report 2016 R 10188 Available from: <a target="_blank" href="https://www.researchgate.net/publication/303809697_On-road_determination_of_average_Dutch_driving_behaviour_for_vehicle_emissions">https://www.researchgate.net/publication/303809697_On-road_determination_of_average_Dutch_driving_behaviour_for_vehicle_emissions</a> (2016)</li><li>Bosteels, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real+Driving+Emissions+and+Test+Cycle+Data+from+4+Modern+European+Vehicles.">Real Driving Emissions and Test Cycle Data from 4 Modern European Vehicles.</a> , (2014).</li><li>Vlachos, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Euro+6+Real-Driving+Emissions+(RDE)+procedure+for+light-duty+vehicles:+Effectiveness+and+practical+aspects.">The Euro 6 Real-Driving Emissions (RDE) procedure for light-duty vehicles: Effectiveness and practical aspects.</a> , (2016).</li><li>Giechaskiel, B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vehicle+emission+factors+of+solid+nanoparticles+in+the+laboratory+and+on+the+road+using+Portable+Emission+Measurement+Systems+(PEMS).">Vehicle emission factors of solid nanoparticles in the laboratory and on the road using Portable Emission Measurement Systems (PEMS).</a> Front. Environ. Sci. 3 (82), (2015).</li><li>. Preliminary uncertainty assessment. Presentation given to the European Commission, RDE Task Force on Uncertainty Evaluation Available from: <a target="_blank" href="https://circabc.europa.eu/sd/a/a4c8455f-de18-4f3a-9571-9410827c4f87/2015_10_01_Error_analysis_JRC.pdf">https://circabc.europa.eu/sd/a/a4c8455f-de18-4f3a-9571-9410827c4f87/2015_10_01_Error_analysis_JRC.pdf</a> (2015)</li></ol>

The views expressed here are those of the authors and may not be regarded as the official position of the European Commission.
Mention of trade names or commercial products does not constitute endorsement or recommendation by the authors or the European Commission.

In this paper, the RDE procedure was described. Several points deserve special attention and will be discussed in more detail here.
For type approval purposes, it is obligatory to determine the exhaust gas flow using equipment such as an EFM functioning without any connection to the ECU of the vehicle. Regarding vehicle preparation, the connection between the EFM and the tailpipe is important. The materials should be temperature- and exhaust gas composition-resistant. Although this is not so critical for NOx, it will be significant for particle number sampling, where desorption of deposited material can lead to artificially high emissions. In addition, points that can accumulate condensates should be avoided. The condensates formed during accelerations can enter into the measurement systems and damage or block them. The sampling points of the analyzers are connected downstream of the EFM in order to ensure that the whole flow passes through the EFM. In case this is not possible and they are connected upstream of the EFM, a correction for the extracted flow has to be made. The analyzers should be connected downstream of the EFM, without any modifications to the length of the sampling lines. If this is not possible, the residence time in the extra tubing has to be taken into account in the software in order to ensure correct emission calculations. The analyzers can be installed inside or outside of the vehicle, as long as safety requirements are met. Moreover, the calibration of the analyzers requires attention. It has to be done within the expected range of emissions of the vehicle. Otherwise, the requirement of 90% coverage of 99% of the measurements of the valid parts of the emissions test might not be fulfilled.
The trip verification and the calculation of the emissions are typically conducted by the PEMS software. For normal driving, all conditions can be easily met17. For example, based on our measurements, a normally driven trip is well within the dynamic boundary limits (Figure 4). However, aggressive driving can be within the pass zone, especially during the urban or motorway portions. On the other hand, data in Dutch cities show that normal driving can also exceed these limits18. In the future, experience over time, tests conducted closer to the boundary conditions, and evaluation methods that show differences of &#62;50% will assess the applicability of the procedure11,19.
A source of uncertainty originates from the determination of road loads for the measurement of CO2 emissions with the WLTC; these measurements are used to evaluate the normality of driving conditions with the RDE data evaluation. Ideally, the chosen road loads resemble those of the unloaded vehicle tested with the PEMS on the road. The flexibilities granted in by the WLTP (e.g., to determine the road load based on conservative generic parameters or the vehicle with the highest test mass within a family) may cause substantial deviations in the CO2 emissions determined by the WLTC and measured later on the road. In consequence, the methods may yield a biased evaluation of the actual driving severity. The WLTP provisions for setting the road load may potentially need to be specified for RDE purposes.
It should be noted that, in comparison to the European heavy-duty in service conformity regulation, there are some differences (e.g., drift correction is allowed, OBD connection is necessary in order to calculate emissions in g/kWhr) due to the different type approval procedure for the heavy-duty vehicles (engines)6. The differences are out of the scope of this paper. With the US in-use-compliance regulation, there are more differences in the evaluation method.
Worldwide, RDE marks the first regulatory on-road test for light-duty vehicles. The RDE provisions defined in Regulation 2016/427 mark the first relevant instance for the type approval of light-duty vehicles in Europe, where RDE complements the standard vehicle testing under controlled conditions in the laboratory. The RDE test procedure allows for testing, and thus controlling, vehicle pollutant emissions under a wide range of operating conditions and in a more robust and comprehensive manner than the currently-applied laboratory testing with a predefined driving cycle.
Nevertheless, RDE is also subject to limitations. First, modal emission measurements on the road over long time periods entails the risk of analyzer drift (e.g., due to variability in ambient temperature). On-road emission measurements are thus subject to larger uncertainty margins (estimated at a maximum of 20-30% at the applicable emissions limit for NOx)21 than emission measurements in the laboratory, even if PEMS analyzers fulfill similar requirements regarding accuracy and precision as laboratory analyzers. Second, the handling of PEMS equipment requires training; conducting emission tests on the road is not yet plug-and-play, and it requires an expert. As on-road testing with PEMS is still rather novel, training that allows auto makers and technical services to acquire and share best practices is needed. The present article is an attempt to disseminate knowledge on the handling of PEMS and the testing of vehicle emissions on the road. Larger-scale experience with the RDE provisions, as can be obtained by inter-laboratory exercises or through benchmarking against existing international legislation, is still missing. As RDE constitutes the first on-road test procedure for light-duty vehicles worldwide, the European Commission foresees an annual review of conformity factors and a more comprehensive review of the entire RDE procedure in the midterm.
There are two major areas for future application. First, RDE may be adopted by other countries. China, India, Japan, and South Korea are interested in adopting RDE, or elements thereof, for regulatory purposes. As such, the procedure described here may become the blueprint for regulatory on-road emissions testing of light-duty vehicles around the world. Second, RDE presents a good practice guide for any independent emission test performed by research institutions and technical services. The provisions help ensure accurate and robust on-road emission measurements.

Vehicles are tested in controlled laboratory conditions to determine their official emission values and fuel consumption (e.g., United Nations Economic Commission for Europe (UNECE) Regulation 83)1. For light-duty vehicles, Regulation 715/20072 defines the Euro 5 and 6 emission limits, to which vehicles in categories M1, M2 (passenger cars), N1, and N2 (vehicles for the carriage of goods) must comply. Compliance is verified by the so-called &#34;Type I&#34; test that measures tailpipe emissions after a cold start during a standardized test in the laboratory1. Although laboratory testing ensures reproducibility and comparability of results, it covers only a small range of the ambient, driving, and engine operating conditions that typically occur on the road. As a matter of fact, official laboratory test results reflect less and less the actual fuel consumption experienced by drivers on the road3. In addition, on-road vehicle emissions, specifically the NOX emissions of diesel cars, are also higher than the type-approval values4-5. Regulation 715/20072 contains provisions to ensure that the emission limits are respected under normal vehicle operation and use. Various new regulatory components are in the pipeline in order to reduce observed discrepancies, such as the World Harmonized Light-Duty Procedure (WLTP), mainly for CO2 and fuel consumption, and the Real-Driving Emissions (RDE) test procedure, mainly for pollutants.
Admittedly, the most important component of the new regulatory package for conventional pollutants is that compliance with the emission limits needs to be demonstrated over real-world vehicle operation following the RDE procedure. The new procedure will complement the measurement of emissions on the chassis dynamometers, so that a thorough control of regulated pollutants is achieved both in the laboratory and on the road. The RDE is based upon on-road emissions testing with the Portable Emissions Measurement Systems (PEMS). PEMS are not new, especially for heavy-duty vehicle testing. The United States Environmental Protection Agency (US-EPA) has added to the laboratory certification tests additional emissions requirements with the Not-To-Exceed (NTE) concept based on vehicle testing with PEMS. In Europe, PEMS-based In-Service Conformity (ISC) provisions for the EURO VI standards are applicable for EURO V engines6,7. PEMS measure emissions in the engine exhaust with a measurement performance (e.g., linearity, accuracy) that is comparable to that of laboratory-grade equipment8. The newest generation of PEMS weigh 30 kg, are compact, and can be easily installed in small passenger cars, thus having a minor impact on the vehicle.
To cope with the real-world variability of testing conditions, specific testing and data evaluation procedures must be implemented. Testing may occur under a wide range of altitude, temperature, and driving conditions. However, requirements concerning (i) trip composition (e.g., roughly equal shares of urban, rural, and motorway driving) and (ii) driving dynamics (e.g., the permissible range of accelerations) aim to ensure that vehicles are tested in a fair, representative, and reliable manner. Still, due to a number of factors (e.g., traffic, driver, and wind), any on-road test remains, to some extent, random and non-reproducible. Thus, the main challenge was the development of a data evaluation method that assesses ex post the normality of test conditions to enable a reliable assessment of vehicle emissions. To this end, two methods were adopted within the RDE: the moving averaging windows (MAW) and the power binning method. The MAW method divides the test into sub-sections (windows) and uses the distance-specific average 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 through a comparison with a standardized wheel-power frequency distribution. Both methods include criteria to ensure that a realized test covers the range of driving dynamicity permitted by the RDE test procedure9-10. The two methods typically give results within 10%; however, differences on the order of 50% have been reported11,12. An in-depth assessment of the two data evaluation methods is still missing. The European Commission acknowledges this shortcoming in Recital 14 of the RDE Regulation13,14 and foresees a review of these two methods in the near future with the objective of retaining them or developing a unified method for the evaluation of gaseous pollutants and particle number emissions.
Until now, two RDE packages have been adopted by the Technical Committee on Motor Vehicles (TCMV) of the EU Member States and became law after their publication in the Official Journal of the European Union13-15. The first RDE package covered the boundary conditions, the actual test procedure, the PEMS specifications, and the data evaluation methods (MAW and/or power binning), but not emission limits (the package was voted on by the TCMV on the 18th of May 2015). The second RDE package added the not-to-exceed (NTE) emission limits applicable to RDE testing. In addition, complementary boundary conditions were introduced to check the excess or absence of driving dynamics. The emissions of each valid individual RDE test must be below the respective NTE emission limit, referred to in the regulation as conformity factors. Currently, only NOx emissions are covered. Binding conformity factors will be introduced in two steps: a factor 2.1 of the Euro 6 NOx limit (80 mg/km) will be applicable from 2017-2019 for new type approvals and all new car registrations. The conformity factor will subsequently be lowered to 1.5 in 2020-2021. The final Euro 6 conformity factor of 1.5 provides an allowance of 0.5 (i.e., 50%) for the additional measurement uncertainty of PEMS compared to laboratory equipment and the test-to-test emissions variability within the possible ranges of testing conditions (e.g., temperature, dynamics, and altitude). Regarding CO, although binding conformity factors are currently not discussed, on-road CO emissions have to be measured and recorded to obtain type approval. The second package was voted on by the TCMV on the 28th of October 2015.
The kick-off meeting of two additional packages was held on the 25th of January 2016. The third RDE package will address particle number PEMS testing, cold start emissions, and the testing of hybrid vehicles. Measuring particle number emissions on-board vehicles is challenging, as no verified technique has yet been established. New concepts and approaches were developed in the period between 2013 and 2014, including electrical detection of aerosol in real-time combined with constant flow sampling16. This package is to be voted on in the second half of 2016. The fourth RDE package will deal with the definition of requirements for in-service conformity and market surveillance testing. Completion of this package is foreseen by early 2017. The RDE Regulations 2016/42713 and 2016/64614 are currently integrated together with the Worldwide Harmonized Light-duty Vehicles Test Procedure (WLTP) into a larger EU type approval regulation that will supplement Regulation 715/20072.
The objective of this paper is to present the experimental procedures required by the newly-adopted RDE regulation. The RDE test procedure defines the boundaries of permissible test conditions, the protocol for testing vehicles, the requirements for instruments, and the evaluation methods to be applied for analyzing vehicle operation and the related pollutant emissions (Table 1). The procedure can be summarized in six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. If any of the requirements in any of these six steps is not met, the test is considered failed. For a more detailed description of the RDE test procedure, the reader can refer to the regulation itself13-14.
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Annex IIIA of EC Regulation 692/2008</td>
		</tr>
		<tr>
			<td>1. Introduction, definitions and abbreviations</td>
		</tr>
		<tr>
			<td>2. General requirements on conformity factors</td>
		</tr>
		<tr>
			<td>3. RDE test to be performed</td>
		</tr>
		<tr>
			<td>4. General requirements</td>
		</tr>
		<tr>
			<td>5. Boundary conditions</td>
		</tr>
		<tr>
			<td>6. Trip requirements</td>
		</tr>
		<tr>
			<td>7. Operational requirements</td>
		</tr>
		<tr>
			<td>8. Lubricating oil, fuel and reagent</td>
		</tr>
		<tr>
			<td>9. Emissions and trip evaluation</td>
		</tr>
		<tr>
			<td>Appendices</td>
		</tr>
		<tr>
			<td>Appendix 1:Test procedure for vehicle emissions testing with a PEMS</td>
		</tr>
		<tr>
			<td>Appendix 2: Specifications and calibration of PEMS components and signals</td>
		</tr>
		<tr>
			<td>Appendix 3: Validation of PEMS and non-traceable exhaust mass flow rate</td>
		</tr>
		<tr>
			<td>Appendix 4: Determination of emissions</td>
		</tr>
		<tr>
			<td>Appendix 5: Verification of trip dynamic conditions with method 1 (Moving Averaging Window)</td>
		</tr>
		<tr>
			<td>Appendix 6: Verification of trip dynamic conditions with method 2 (Power Binning)</td>
		</tr>
		<tr>
			<td>Appendix 7: Selection of vehicles for PEMS testing at initial type approval</td>
		</tr>
		<tr>
			<td>Appendix 7a: Verification of overall trip dynamics</td>
		</tr>
		<tr>
			<td>Appendix 7b: Procedure to determine the cumulative positive elevation gain of a trip</td>
		</tr>
		<tr>
			<td>Appendix 8: Data exchange and reporting requirements</td>
		</tr>
		<tr>
			<td>Appendix 9: Manufacturer&#39;s certificate of compliance</td>
		</tr>
	</tbody>
</table>
Table 1: Structure of the RDE regulation. The regulation is considered to be ANNEX IIIA of Commission Regulation 692/200810. All parts and appendices are described in Commission Regulation 2016/427 (the first package)8. Appendices 7a and 7b, as well as the conformity factors, are described in Commission Regulation 2016/646 (the second package)9.

<table border="0" cellpadding="0" cellspacing="0" width="776">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">PEMS analyzer</td>
			<td style="width:103px;">Sensors Inc.</td>
			<td style="width:163px;">SEMTECH ECOSTAR</td>
			<td style="width:264px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">PEMS analyzer</td>
			<td style="width:103px;">AVL</td>
			<td style="width:163px;">MOVE</td>
			<td>Figure 2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">PEMS analyzer</td>
			<td style="width:103px;">Horiba</td>
			<td style="width:163px;">OBS</td>
			<td>Figure 2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">PEMS analyzer</td>
			<td style="width:103px;">MAHA</td>
			<td style="width:163px;">PEMS-GAS</td>
			<td>Figure 2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Exhaust Flow meter</td>
			<td style="width:103px;">Sensors Inc.</td>
			<td style="width:163px;">SEMTECH EFM-HS</td>
			<td>EFM-HS specifications of Table 4</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">GPS</td>
			<td style="width:103px;">Garmin</td>
			<td style="width:163px;">Drive 50</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Weather station</td>
			<td style="width:103px;">Waisala</td>
			<td style="width:163px;">AWS310</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Zero gas</td>
			<td style="width:103px;">Air Liquide</td>
			<td style="width:163px;">AL089</td>
			<td>Alphagaz 1 (N2)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Span gas</td>
			<td style="width:103px;">Air Liquide</td>
			<td style="width:163px;">SM190022710IT</td>
			<td>1800 ppm NO in N2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Span gas</td>
			<td style="width:103px;">Air Liquide</td>
			<td style="width:163px;">SM190022710IT</td>
			<td>13% CO2 in N2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;">Batteries</td>
			<td style="width:103px;">Discover</td>
			<td style="width:163px;">EV12A-A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:247px;"></td>
			<td style="width:103px;"></td>
			<td style="width:163px;"></td>
			<td></td>
		</tr>
		<tr height="43">
			<td colspan="4" height="43" style="height:43px;width:776px;">Mention of trade names or commercial products does not constitute endorsement or recommendation by the authors or the European Commission</td>
		</tr>
	</tbody>
</table>

implementation of portable emissions measurement systems (pems) for the real-driving emissions (rde) regulation in europe

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. However, on the road, ambient and driving conditions can vary over a wide range, sometimes causing emissions to be higher than those measured in the laboratory. For this reason, the European Commission has developed a complementary Real-Driving Emissions (RDE) test procedure using the Portable Emissions Measurement Systems (PEMS) to verify gaseous pollutant and particle number emissions during a wide range of normal operating conditions on the road. This paper presents the newly-adopted RDE test procedure, differentiating six steps: 1) vehicle selection, 2) vehicle preparation, 3) trip design, 4) trip execution, 5) trip verification, and 6) calculation of emissions. Of these steps, vehicle preparation and trip execution are described in greater detail. Examples of trip verification and the calculations of emissions are given.

An example of the function of the RDE requirements will be given.
Select and prepare the vehicle and design and conduct the trip: This was not a type approval test but an application of the RDE procedures. Thus, the selected vehicle, a Euro 5B light-duty turbocharged gasoline direct injection vehicle (1.2-L engine displacement), was already available in the JRC laboratory. An RDE-compliant trip was selected (Figure 3). After installation and preparation of the PEMS, the trip was conducted.
<img alt="Figure 3" src="/files/ftp_upload/54753/54753fig3.jpg" /> 
Figure 3: Trip design. A trip that includes urban (&#8804;60 km/hr), rural, and motorway (&#62;90 km/hr) parts in equal shares is shown. The design is based on the speed limits of the chosen roads. <a href="http://cloudflare.jove.com/files/ftp_upload/54753/54753fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
Verify the trip: The trip was verified by checking (i) the boundary and operation conditions and (ii) the normality of driving. The boundary and operation conditions and the trip requirements were fulfilled (Table 5). The ambient temperature and the maximum altitude were both within the moderate limits of 0-30 &#176;C and &#8804;700 m, respectively. The trip consisted of urban driving followed by rural and motorway driving. It lasted 96 min and covered a distance of at least 16 km for each of the U/R/M portions. The distance shares were within 29-44% for the urban part and 23-43% for the rural and motorway parts. The trip showed stop periods, defined as periods with a vehicle speed of less than 1 km/hr, in the prescribed range of 6-30% of the urban operation duration. As far as the vehicle speed profiles are concerned, the test showed a motorway operation that properly covered (i) the range between 90 and 110 km/hr and (ii) speeds above 100 km/hr for at least 5 min. The maximum vehicle speed was well below the threshold of 145 km/hr, while the average speed of the urban driving part of the trip, including stops, was within the permissible range of 15-40 km/hr. The cumulative positive elevation gain over the entire trip was below the limit of 1,200 m per 100 km. The altitude difference between the start and end points was &#60;100 m. The relative positive acceleration and the 95th percentiles of the speed multiplied by the positive acceleration were within the limits (see Figure 4). Experimental data with more aggressive driving using the same car, as well as other tests reported in the literature, are shown for comparison17,18.
<img alt="Figure 4" src="/files/ftp_upload/54753/54753fig4.jpg" /> 
Figure 4: Indices to check the excess or absence of driving dynamics. (a) 95th percentile of the product of instantaneous speed and positive acceleration during urban, rural, and motorway driving. (b) Relative positive acceleration during urban, rural, and motorway driving. The open squares are the experimental results. The open triangles are results with aggressive driving in the same car. The asterisks are aggressive trips in German cities. The continuous line shows the permitted limits. The pass or fail areas are also shown. <a href="http://cloudflare.jove.com/files/ftp_upload/54753/54753fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Conditions</td>
			<td>Units</td>
			<td>Limits</td>
			<td>Trip</td>
			<td>Urban</td>
			<td>Rural</td>
			<td>Motorway</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td>Speed</td>
			<td>[km/hr]</td>
			<td></td>
			<td></td>
			<td>&#8804;60</td>
			<td>60&#60;v &#8804;90</td>
			<td>v&#62;90</td>
			<td></td>
		</tr>
		<tr>
			<td>Payload</td>
			<td>[%]</td>
			<td>90</td>
			<td>75</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Ambient temperature</td>
			<td>[&#176;C]</td>
			<td>-7&#8230;+35</td>
			<td>19</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok (moderate)</td>
		</tr>
		<tr>
			<td>Max. altitude</td>
			<td>[m]</td>
			<td>&#8804;1,300</td>
			<td>302</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok (moderate)</td>
		</tr>
		<tr>
			<td>Start/End altitude difference</td>
			<td>[m]</td>
			<td>&#60;100</td>
			<td>40</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Cumulative positive elevation gain</td>
			<td>[m/100 km]</td>
			<td>&#60;1,200</td>
			<td>636</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Relative Positive Acceleration</td>
			<td>[m/sec2]</td>
			<td>Figure 4</td>
			<td></td>
			<td>0.215</td>
			<td>0.134</td>
			<td>0.100</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>speed x positive acceleration</td>
			<td>[m2/sec3]</td>
			<td>Figure 4</td>
			<td></td>
			<td>15.5</td>
			<td>22.7</td>
			<td>21.4</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Trip duration</td>
			<td>[sec]</td>
			<td>90-120</td>
			<td>96</td>
			<td></td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Distance covered</td>
			<td>[km]</td>
			<td>&#62;16</td>
			<td></td>
			<td>29</td>
			<td>27</td>
			<td>23</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Share</td>
			<td>[%]</td>
			<td>23(29)-43</td>
			<td></td>
			<td>36.7</td>
			<td>34.2</td>
			<td>29.1</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Stop time (of Urban duration)</td>
			<td>[%]</td>
			<td>&#160;6-30</td>
			<td></td>
			<td>28.8</td>
			<td></td>
			<td></td>
			<td>ok</td>
		</tr>
		<tr>
			<td>v&#62;100 km/hr</td>
			<td>[min]</td>
			<td>&#8805;5</td>
			<td></td>
			<td></td>
			<td></td>
			<td>9.7</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>v&#62;145 km/hr (of Motorway time)</td>
			<td>[%]</td>
			<td>&#60;3</td>
			<td></td>
			<td></td>
			<td></td>
			<td>0</td>
			<td>ok</td>
		</tr>
		<tr>
			<td>Average speed (Urban part)</td>
			<td>[km/hr]</td>
			<td>15-40</td>
			<td></td>
			<td>28</td>
			<td>75</td>
			<td>114</td>
			<td>ok</td>
		</tr>
	</tbody>
</table>
Table 5: Summary of trip evaluation. The boundary conditions; the test requirements; and the results obtained before and/or during the trip for the urban, rural, and motorway portions, respectively, are listed.
The normality of driving was conducted with the MAW evaluation method, excluding cold start and idling and weighing the NOx emissions with CO2 emission deviations greater than 25% of the type approval cycle according to the MAW method (see Appendix 5)8. The free EMROAD software was used.
Calculate the RDE emissions: The analysis of the results was also conducted with the EMROAD software. The results can be seen in Figure 5. The urban NOx emissions were at the same level as or lower than the respective WLTC phases emissions (0.02 g/km). The rural and motorway emissions were &#62;0.05 g/km higher than the respective WLTC phases. On average, the on-road emissions were 0.056 g/km, which is lower than the NTE limit (for this case, 0.06 mg/km x 2.1 conformity factor). Thus, this specific vehicle would pass the RDE test (even though the RDE procedure is not applicable to Euro 5 vehicles). More examples can be found elsewhere17-18.
<img alt="Figure 5" src="/files/ftp_upload/54753/54753fig5.jpg" /> 
Figure 5: MAW NOx emissions of the road trip as a function of the MAW speed. The blue squares show the average NOx emissions of each moving averaging window as a function of the respective window-average vehicle speed. Solid diamonds depict the mean on-road NOx emissions of all windows representing urban, rural, and motorway driving. White circles depict the laboratory NOx emissions over the four phases of the WLTP. <a href="http://cloudflare.jove.com/files/ftp_upload/54753/54753fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>

Watch this Scientific Journal Video about Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe at JoVE.com

Implementation of Portable Emissions Measurement Systems PEMS for the Real-driving Emissions RDE Regulation in Europe

The European Commission has developed a Real-Driving Emissions (RDE) test procedure to verify pollutant emissions during real-world vehicle operation using the Portable Emissions Measurement Systems (PEMS). This paper presents the experimental procedures required by the newly-adopted RDE test.

Implementation of Portable Emissions Measurement Systems (PEMS) for the Real-driving Emissions (RDE) Regulation in Europe

Vehicles are tested in controlled and relatively narrow laboratory conditions to determine their official emission values and reference fuel consumption. ...

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