Unter der Leitung der Working Party 29 beauftragte die UN ECE Group of Experts on Pollution and Energy (GRPE) die ad-hoc Arbeitsgruppe WMTC mit der Entwicklung eines "Worldwide Harmonised Motorcycle Emissions Test ProCedure". Das Ziel dieses Forschungsprogramms ist es, einen weltweit harmonisierten Pruefzyklus fuer die Messung der Schadstoffemissionen motorisierter Zweiraeder zu entwickeln, der den Fahrzyklus und den dazugehoerigen Schaltalgorithmus fuer die Pruefstandmessungen und die Beschreibung der Einstellungen der Pruefstaende abdeckt. Mit dem Vorhaben sollte darueber hinaus aber noch das Ziel verfolgt werden, einen Vorschlag fuer die Erfassung von off-cycle Emissionen zu erarbeiten. Der Begriff "off-cycle Emissionen" umfasst diejenigen Emissionen eines Motorrades, die im realen Betrieb bei Fahrzustaenden auftreten, die durch den Pruefzyklus nicht erfasst werden. Um eine geeignete Loesung fuer die Erfassung von off-cycle Emissionen zu finden wurden die im Rahmen der WMTC Arbeiten zur Verfuegung stehenden in-use Daten zum Fahrverhalten von Motorraedern noch einmal auf ihre Varianzen hin ausgewertet. Wichtig im Zusammenhang mit der Bewertung von off-cycle Emission provisions ist ausserdem die Diskussion und Festlegung von Grenzwerten fuer den off-cycle Bereich. Bei Fahrzeugen, die mit einem 2-Wege-Katalysator mit Lambdasondenregelung ausgeruestet sind, bietet die Erfassung der Lambdasondenspannung ein ergaenzendes Hilfsmittel, um die Funktion der Regelung des Katalysators zu ueberpruefen. Sie sollte nicht nur im off-cycle Bereich sondern ebenfalls im normalen WMTC angewendet werden. Bericht zum Forschungsprojekt 89.106/2001 (ITRD-Nummer D707343) der Bundesanstalt fuer Strassenwesen. Titel in Englisch: Investigations into motorcycle exhaust emissions carried out as part of WMTC activities. English abstract : Under the direction of Working Party 29, the UN ECE Group of Experts on Pollution and Energy (GRPE) commissioned the WMTC ad-hoc working group to develop a "World-wide Harmonised Motorcycle Emissions Test ProCedure". The aim of this research programme is to develop a world-wide harmonised series of tests for measuring harmful substances emitted by motorised two-wheelers; these tests should cover the driving cycle and the relevant transmission algorithm for the test facility measurements, and describe the settings of the test facilities. The validation of the emissions in part 2 of the validation programme was funded partly by the industrial sector (IMMA) and partly by the national governmental institutions in different countries. For Germany, the Federal Highway Research Institute (Bundesanstalt für Straßenwesen - BASt) conducted this research project, which included having validation tests carried out on 8 motorcycles at RWTÜV Fahrzeug GmbH in Essen. The results are documented in the first part of the report (the long version). Another aim of the project was to draw up a proposal for recording off-cycle emissions. The term "off-cycle emissions" is used to describe the emissions from a motorcycle which occur during real operation in driving circumstances which are not covered by the series of tests. In this regard, off-cycle emissions constitute a fundamental problem, even with a representative series of measurements. For example, emissions which occur as a result of free revving and rapid acceleration are not covered in the WMTC. To find a suitable solution for recording off-cycle emissions, the in-use data on motorcycle driving performance which were available during the WMTC work were evaluated once more to assess the variances which existed and to consequently determine the engine speeds and vehicle accelerations which should be taken into account for off-cycle emissions. Three different methods for recording off-cycle emissions were investigated, WMTC with increased transmission speeds, the Load Response Test and stationary speed/engine speed combinations. The following overall conclusion can be drawn from the off-cycle emission results: Stationary engine speeds are unsuitable for determining off-cycle emissions. Applying the "increased transmission speeds" approach to the WMTC speed sequence is a step in the right direction, but it does not take into account the more rapid accelerations which occur as a result of "sporty" driving. The load response test is a suitable approach for testing off-cycle emissions. However, to use it in practice binding transmission speeds must be laid down and provisions made to reduce the danger of tyre slip and consequently improve repeatability. The constant driving phases should be used to record emission behaviour at higher engine speeds than the normal WMTC transmission speeds. It was also not possible in this project to conclusively clarify how the results should be evaluated. The start and finish speeds should be randomised to make cycle bypass measures more difficult. Discussing and laying down off-cycle limit values are important issues regarding the evaluation of off-cycle emission provisions. For vehicles which are equipped with a 3-way catalytic converter with lambda sensor control, the recording of the lambda sensor voltage offers additional assistance in testing the control of the catalytic converter. It should be used in the normal WMTC as well as for off-cycle tests. (Author/publisher) The English abstract is also available at: http://www.bast.de/htdocs/veroeffentlichung/kurzfass/f45.htm.
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