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Object-oriented or component-based modeling greatly facilitates model development for large and complex multi-domain physical systems. It uses predefined and reusable component models. Connections between component models represent actual physical connections. Non-physical connections are not needed. Therefore, the model is much easier to be understood and used by general model users. The purpose of this paper is to demonstrate that object-oriented modeling is very suitable for mean-value engine models. Models for throttle, intake manifold, EGR valve and cylinder are developed separately and assemble together through connections. The component models are built from first principles in thermodynamics. Bidirectional flows are allowed at all ports for every component. The intake manifold uses mass, temperature and EGR mass fraction as state variables. Simulation results of a typical engine are included.

General Motors recently demonstrated two driveable test vehicles powered by a Homogeneous Charge Compression Ignition (HCCI) engine. HCCI combustion has the potential of a significant fuel economy benefit with reduced after-treatment cost. However, the biggest challenge of realizing HCCI in vehicle applications is controlling the combustion process. Without a direct trigger mechanism for HCCI's flameless combustion, the in-cylinder mixture composition and temperature must be tightly controlled in order to achieve robust HCCI combustion. The control architecture and strategy that was implemented in the demo vehicles is presented in this paper. Both demo vehicles, one with automatic transmission and the other one with manual transmission, are powered by a 2.2-liter HCCI engine that features a central direct-injection system, variable valve lift on both intake and exhaust valves, dual electric camshaft phasers and individual cylinder pressure transducers.