ESTIMATING REAL WORLD EMISSIONS FROM PASSENGER CARS - USE AND LIMITATIONS OF INSTANTANEOUS EMISSION DATA

In recent years, many measurements of emissions on chassis-dynamometers have already incorporated the online measurement of emission concentrations at the exhaust as standard, alongside the usual average values. These data collected with a high time resolution (e.g. 1 second) can be combined with the likewise modal-recorded operating condition of the vehicle (engine load) and serve as a basis for methods of calculating emission. Compared to the widely used characterisation of a driving pattern by its average speed only, the explicit dependence of the emission behaviour on the engine load allows the level of dynamics of each driving situation individually to be taken into account. A reliable emission data set gives the possibility of calculating emissions for different real world driving conditions. For many applications, it is thereby no longer necessary to early out costly and time-consuming chassis-dynamometer tests. Generation of emission data sets takes place on chassis-dynamometers using different driving patterns. Systematic investigations should show the requirements necessary for generation of instantaneous emission matrices, and how important a reliable consideration of driving kinematics is in estimating emissions for real world driving accurately.