Automotive Engine Modelling for Real-Time Control Using an Object-Oriented Simulation Library

Theoretical simulation models are useful tools in the design of engine management systems, allowing to reduce resources invested in the product development. Their applications range from optimisation of control systems to hardware-in-the-loop testing (HIL) and to model-based control and diagnostic strategies. Even if several control-oriented models are proposed in the open literature for spark ignited engines only in the last years a similar attention has been devoted to automotive Diesels, which on the other hand are becoming more and more widely used due to their low specific fuel consumption (and to their low CO2 specific emissions). The paper describes a control-oriented theoretical tool developed in MatLabâ/SimuLinkâ for the simulation of a turbocharged direct injection (DI) Diesel engine, with common rail (CR) injection system and exhaust gas recirculation (EGR). Starting from a previous steady-state Mean Value Engine Model (MVEM) proposed by the author, a specific SimuLinkâ library was built up to describe components and subsystems: defined blocks can be easily assembled together in a modular structure to reproduce the whole engine layout. Quasi-steady flow and filling-and-emptying techniques are used, while combustion process is described following a single-zone approach. In the paper the library is presented, together with an application to a typical automotive CR Diesel engine.