Powertrain digital twinning for real-world emissions compliance

The scheduled introduction of EU7 emissions regulations has increased the depth of field for real-world emissions compliance. Whilst EU6 emissions legislation provided clear boundaries by which vehicle and powertrain Original Equipment Manufacturers (OEMs) could develop and calibrate against, the more stringent emissions limits and wider real-world driving test fields of EU7 are more difficult to ensure compliance with. In-house and in-field physical testing to assess emissions compliance of a vehicle and powertrain will not be enough to ensure emissions produced during real-world driving are below the legislative limits. It is likely therefore that OEMs will need to adopt some aspect of virtual engineering to supplement physical testing. In this respect, the HORIBA Intelligent Lab virtual engineering toolset has been created and deployed to produce empirical digital twins of a modern light-duty electrified gasoline Internal Combustion Engine (ICE) and a commercial vehicle diesel ICE. The former was created with the specimen tested on an engine dynamometer with the latter ICE tested using chassis dynamometer methodologies. Both powertrains were exercised across their entire operational ranges with the subsequent performance and emissionsmeasurements used to create corresponding transient empirical response models. The validated transient empiricalmodels for the electrified ICE were then coupled with data extracted from virtual driving scenarios adopting a light-duty Sports Utility Vehicle (SUV); predictions of performance and emissions attributes for these scenarios were subsequently made. The diesel transient empirical models were coupled with data extracted fromvirtual driving scenarios utilising a commercial goods vehicle; again, predictions of performance and emissions attributes for these scenarios were subsequently made. By creating an empirical digital twin of a powertrain using engine or chassis dynamometer testing methodologies, the predictions made can be used to rapidly identify unfavourable powertrain operating conditions or problematic driving scenarios before product launch.