Crank-Angle Resolved Real-Time Capable Engine and Vehicle Simulation - Fuel Consumption and Driving Performance

The present work introduces a fully integrated real-time (RT) capable engine and vehicle model. The gas path and drive line are described in the time domain of seconds whereas the reciprocating characteristics of an IC engine are reflected by a crank angle resolved cylinder model. The RT engine model is derived from a high fidelity 1D cycle simulation and gas exchange model to support an efficient and consistent transfer of model data like geometries, heat transfer or combustion. The workflow of model calibration and application is outlined and base ECU functionalities for boost pressure, EGR, smoke and idle speed control are applied for transient engine operation. Steady state results of the RT engine model are compared to experimental data and 1D high fidelity simulations for 19 different engine load points. In addition an NEDC (New European Drive Cycle) is simulated and results are evaluated with data from chassis dynamometer measurements. A full load acceleration is simulated with the RT engine model and compared to results of a simple map based engine model. The simulation results underline that the model correctly predicts steady-state engine behavior. Moreover, transient simulation results are consistent with the chassis dynamometer measurements and the simulation model responds sensitively and adequately to changed control values during drive cycle conditions. The model also fully captures the complex phenomena delaying torque build-up during full load acceleration. The integrated engine and vehicle approach simplifies the harmonization of engine and vehicle parameters to meet future requirements on driving performance, fuel consumption and emissions.