Modeling of a Diesel Engine with VGT and EGR including Oxygen Mass Fraction

A mean value model of a diesel engine with VGT and EGR and that includes oxygen mass fraction is developed and validated. The intended model applications are system analysis, simulation, and development of model-based control systems. Model equations and tuning methods are described for each subsystem in the model. In order to decrease the amount of tuning parameters, flows and efficiencies are modeled using physical relationships and parametric models instead of look-up tables. The static models have mean relative errors that are equal to or lower than 6.1%. Static and dynamic validations of the entire model show that the mean relative errors are less than 12%. The validations also show that the proposed model captures the essential system properties, i.e. a non-minimum phase behavior in the transfer function EGR-valve to intake manifold pressure and a non-minimum phase behavior, an overshoot, and a sign reversal in the transfer function VGT to compressor mass flow.When citing this work, it is recommended that the citation is the improved and extended work, published in the peer-reviewed article Johan Wahlstr¨om and Lars Eriksson, Modeling diesel engines with a variable-geometry turbocharger and exhaust gas recirculation by optimization of model parameters for capturing non-linear system dynamics, Proceedings of the Institution of Mechanical Engineers, Part D, Journal of Automobile Engineering, Volume 225, Issue 7, July 2011, http://dx.doi.org/10.1177/0954407011398177.