A Real-Time Model for the Simulation of Transient Behaviour of Automotive Diesel Engines 2006-01-3007
In automotive applications problems related to control and diagnostics play an important role in the improvement of engine performance and in the reduction of fuel consumption and pollutant emissions. In this field theoretical models proved to be very useful, with applications that range from the definition of optimised management systems, to hardware-in-the-loop testing (HIL) and to model-based control strategies. However, control-oriented applications has to cope with the increasing complexity of actual automotive engines.
In order to define “real-time” theoretical models for these applications, an original library has been developed by the authors for the simulation of complex systems [9,10,11], as intake and exhaust systems of automotive Diesel engines. “Quasi-Steady Flow” models and “Filling-and-Emptying” techniques were used for engine components and sub-systems. The library was then used to build up a theoretical Mean Value Model (MVM) of a small automotive Diesel engine with variable-geometry turbocharger (VGT), EGR and throttle valve.
After a specific calibration on a production Diesel, the model was used for the simulation of engine behaviour allowing for very short calculation time (lower than real-time). Theoretical results were then compared with experimental data measured on a test bench for model validation. The good agreement observed in steady operating conditions was pointed out in . In the present paper the validation is extended to transient operating conditions. Simulation results are compared with experimental data from on-road tests, highlighting the capabilities of the model to describe engine transient behaviour under the combined effects of VGT and EGR.