RDE Methodology Development for Motorcycle Emissions Assessment

The transfer of conditions and regulations for RDE testing from passenger cars to motorcycles is a non-trivial undertaking. Motorcycles exhibit significant differences in construction and usage compared to cars, necessitating a distinct set of requirements for equipment and methodology. Currently available PEMS are hindered by their relatively large size and weight due to the embedded measurement technology and external power supply. The weight of, at least 50kg, poses a substantial additional load, leading to a deviation and, on average, higher load collective of the engine during RDE measurement rides.
Beyond these structural parameters, the actual propulsion system and subsequent exhaust system introduce another challenge when employing PEMS on motorcycles. An unfavorable combination of the ratio of engine displacement to the volume of the exhaust system and long or unequal ignition intervals leads to pulsations, which has a considerable impact on the differential pressure-based measurement method in the EFM.
To tackle these challenges, this paper presents the verification of a lightweight off-the-shelf PEMS and an EFM tailored for motorcycles. The verification process of the PEMS is conducted on a state-of-the-art two-wheeler chassis dyno, addressing different L-category subclasses (A1 - A3). This verification ensures the reliability and accuracy of the developed methodology across a range of motorcycle types and engine configurations.
Furthermore, the paper provides a detailed RDE measurement example, showcasing the practical application of the developed methodology in real-world scenarios. The mounting platform for motorcycles is described, considering the diverse design configurations and exhaust layouts encountered in various motorcycle categories. Additionally, the integration of complementary devices, such as OBD loggers, enhances the capabilities of the PEMS for comprehensive emissions monitoring during RDE tests.
The RDE example illustrates the use of the lightweight PEMS in capturing emissions data from a motorcycle under diverse operating conditions, validating its utility for regulatory compliance and environmental impact assessment.
In conclusion, this paper contributes to the advancement of RDE methodology for motorcycles by addressing the unique challenges posed by their diverse engine configurations and usage patterns. The development of the methodology including the verification process establishes a robust framework for real-drive emissions testing of LVs.