FEV offers a unique simulation-based virtual test bed to perform a significant part of up to 30 percent of Engine Control Unit (ECU) calibration on virtual and Hardware in the Loop (HiL) test beds, without the need for an engine test bed. It allows the demanding requirements associated with new transient cycles (Worldwide harmonized Light vehicles Test Procedures (WLTP)) and environmental cycles (Real Driving Emissions (RDE) linked to new temperature and altitude conditions) to be met.

Up until now, calibration of the ECU by simulating the engine and its environment has encountered major technical problems:

• With 0D/1D physical or numerical simulation, it is possible to simulate the impact of the engine design on pollutant emissions and fuel consumption and thus define the most suitable concept to achieve the desired performance. However, the level of accuracy is low and not sufficient for ECU calibration.

• On the other hand, design of experiments (DOE) enables reliable statistical models to be created with a limited and reasonable amount of experimental data. As a result, a global DOE enables the modeling and prediction of pollutant emissions and fuel consumption on the whole engine map, taking into consideration specific steady-state operating points, as well as the air path and injection parameters. Accuracy for these operating points (5% to 10% on NOx) is at the requested level for calibration tasks. However, the development of more dynamic cycles with Euro 6/7, such as WLTP and RDE, reveals the limits of this method: Since the acceleration phases are much more present than on the previous NEDC cycle, air loop control errors are becoming more significant. These air loop differences can result in a loss of accuracy in the prediction of pollutant emissions of up to 25% of NOx emissions per cycle.

A powerful combination of technologies

To overcome these challenges, FEV offers an innovative and simple solution based on FEV products, in combination with well-known third-party products: xCAL™ * DOE model for combustion and pollutant emissions and Gamma Technologies GT-SUITE or SIEMENS Amesim for physical modeling of the air path, all together coupled and integrated into MORPHEE integration and automation platforms, to optimize CPU performances, easily set-up automated procedures and even connect a real ECU (HiL). This innovative virtual test bed solution achieves good accuracy levels (5 to 10% on NOx) thanks to the excellent behaviour of the complete air path, thus making it an efficient and reliable virtual calibration platform.

With these virtual test beds, engine settings are tested using simulations and results for emissions and fuel consumption can be quickly and easily obtained on RDE and WLTC cycles for a wide range of applications.

* xCAL™ is a FEV Product.

Benefits

• Decrease of the share of physical tests in an engine development: engine test beds, chassis dyno and vehicle, in standard and non-standard conditions (temperature, altitude…)
• Shorter development time, due to a model based collaborative framework: the simulation, control, calibration and testing teams share the same models, dashboards and variable configuration
• Due to the unique performance of FEV systems, the accuracy of the models remains the same from the MiL step to the validation at the test bed