A real-time model for the simulation of steady and transient behaviour of automotive engines.

In hybrid applications issues related to control and management of thermal engines usually play an important role in the improvement of the vehicle performance and in the reduction of fuel consumption and pollutant emissions. In the design of management strategies the use of theoretical models can be very useful, as widely documented in the open literature. With reference to “real-time” simulation (typical of control-oriented applications) “grey-box” Mean Value Model (MVM) or faster “black-box” models are usually preferred to describe system behaviour. An original simulation library has been developed by the authors in Simulink® environment for the simulation of last-generation automotive engine. Engine components and sub- systems are described through specific blocks that can be assembled to build up a whole engine model. In the paper a theoretical Mean Value Model (MVM) developed with the library for the simulation of a small automotive Diesel engine, with variable-geometry turbocharger (VGT), low- and high-pressure EGR and throttle valve, is described. The model was fitted on automotive Diesel engines allowing for “real-time” simulations. Calculated results are compared in the paper with experimental data measured on a test bench, showing a good agreement.