Application of a systematic development methodology for post-EU6 engine calibration under RDE compliance

The recent European exhaust gas emission legislation has extended its homologation processes with real driving scenario tests on public roads utilizing Portable Emission Measurement Systems (PEMS). This shift from a synthetic test environment on a chassis dyno test bench towards the road as a complex, yet unpredictable, testing ground bears many challenges and significantly enlarges the calibration effort for vehicle manufactures. Methodical adaptations to existing development procedures are inevitable to allow early compliance with Real Driving Emission (RDE) legislation and to prevent over-engineering.In this paper, ISUZU Motors Germany and the Institute for Internal Combustion Engines and Powertrain Systems (VKM) of TU Darmstadt, present results from the process-application of a methodical development approach for post-EU6 engine calibration feasibility and robust RDE compliance.In view of increasing system complexity and high time and cost constrains, it is necessary to ensure functionalities and emission conformity at an early stage of the development cycle. This applies in particular to the emission behaviour of vehicle powertrains under RDE boundary conditions. For early identification and optimization of critical real-driving operating ranges, powertrain-specific Most-Relevant-Tests are developed and generated to be used for validation and calibration purposes at RDE-enabled test bench environments for engine-, powertrain- and vehicle applications. Individual Most-Relevant-Tests are applied in a development and calibration feasibility study and allow a process-evaluation regarding future post-EU6 legislation targets. The OEM calibration process is supplemented with a validation and confidence monitoring process enabling an assessment of the testing regarding RDE compliance. By this an objective definition of RDE development targets to reach conformity, especially with future emission limits, is achievable and RDE testing efficiency could be enhanced.