Control Oriented NOx and Soot Models for Diesel Engines

The further improvement of Diesel engine control and diagnosis requires information on the dynamical soot and NOx formation. Investigations of the air and exhaust path show that process and sensor dynamics play an important role for emission modelling. The simplified combustion process and the emission formation is modelled as a stationary batch process. The air path states and the location of mass fraction burned 50% introduce external dynamics to the stationary model structure. It is shown that the main dynamic influences in emission formation come from the air path states at the engine intake. Additional dynamics result from the gas propagation in the exhaust system and the emission sensors. The presented emission models overcome the measurement dynamics leading to relatively fast dynamic models.