Air System and Diesel Combustion Modeling for Hardware in the Loop Applications

The development of engine control unit (ECU) systems for series production requires an important validation phase. In order to reduce the number of time consuming and expensive vehicle tests, the ECU is validated using hardware in the loop (HIL) test bench. The HIL simulates the engine behavior in real-time simulations to generate consistent sensor values for all engine operating points, e.g., starting phase, transient behavior, static behavior, etc. Mean value engine models (MVEM) are able to run in real time and are appropriate for HIL test systems. In this paper we present a full MVEM taking into account all engine components: air system (air filter, turbocharger, charge air cooler, throttle valve, intake and exhaust manifolds, EGR valve, and turbine), oxidation catalyst (OxiCat), and diesel particulate filter (DPF). Additionally, combustion models have been developed to simulate the influence of the injection strategies (pre, main, post, and late injections) on the exhaust temperature and the unburned hydrocarbon emission (HC). These are taken into consideration in the exothermal reactions models inside OxiCat and DPF. The results show that the model prediction in term of pressure and temperature are in good agreement with the original equipment manufacturer (OEM) project data. The after treatment temperature evolutions in the OxiCat and DPF are well reproduced by the proposed model.