Refinement and Investigation of Instruments for Emission Screening of Passenger Cars

Abstract: A Portable Emissions Measurement System (PEMS) is widely used for analysing the emissions of a vehicle. However, the PEMS is quite cumbersome and time-consuming to use for vehicle testing. This thesis investigates the possibilities of a Smart Emissions Measurement System (SEMS) and how it correlates to the more advanced PEMS. The second factor is of a shortened drive cycle, and how it is compared to the legislated drive cycle. The main hypothesis of this thesis was that a shortened drive cycle with the SEMS equipment should be able to predict the outcome of a full Real Driving Emissions (RDE) test with PEMS equipment with a statistical significance that is large enough to prove the SEMS to be a useful tool. The experiment was performed with a PEMS in parallel with a SEMS on both a shortened and a legislated drive cycle. The study concludes that the SEMS is showing promising results as to how well an RDE test can be predicted, and it would be a useful resource to increase testing on vehicles, both on a shortened and a legislated route. However, as the emissions of light-duty vehicles get smaller, they also get harder to measure with accuracy. This will always be a problem for the SEMS equipment, and even more on a shortened route. As a future application for light-duty vehicles, this might not be the perfect system due to many inaccuracies, but there are many other applications where SEMS could be useful with enough precision, such as heavier and older vehicles.