A detailed Mean Value Model of the exhaust system of an automotive Diesel engine 2008-28-0027
Theoretical models are useful tools in the design of engine control systems, with applications that range from the design of engine layout, the definition of optimised management systems, to hardware-in-the-loop testing (HiL) and to model-based control strategies.
To define theoretical models for control-oriented applications, an original library has been built up at the University of Parma for the simulation of the intake and exhaust systems of automotive turbocharged engines. Starting from this library, a Mean Value Model (MVM) of a Diesel engine, with variable-geometry turbocharger (VGT), EGR and throttle valve, has been developed for a small automotive application.
In the paper the matching of the engine model with a detailed model of the exhaust system (developed by Magneti Marelli Powertrain) is presented. After treatment devices (pre-cat, main-cat and particulate filter) are described through black- and grey-box models, taking account of thermal transients and of soot accumulation/regeneration of the filter. A specific calibration procedure allowed to fit the model to a real automotive application (a Diesel engine with VGT and EGR). Simulations proved to run faster than “real time”, and calculated results in several engine transients are reported in the paper, showing a good agreement with the typical behaviour of the system.