On-Board Monitoring to meet upcoming EU-7 emission standards – Squaring the circle between effectiveness and robust realization

Abstract

The upcoming European emission standards for light as well as heavy-duty road vehicles in the 2025/26 timeframe will include a remote monitoring mandate as a key element of the regulation to ensure continuous ultra-low real world emission behavior. Real-time data regarding tailpipe emission performance for multiple pollutant species will be recorded and compared with the legal limits, summarized under heading On-Board Monitoring (OBM) for defined pollutant species. In addition, engine and exhaust gas aftertreatment operating conditions are required to be collected via an electronic control unit to complete the monitoring status and analysis in the necessary post-processing routines. The EU legal authorities within the rule making sections are on track to define an EU-wide standard that extends the responsibility of the OEMs from emission compliance in pre-defined operating profiles to full in-use emission behavior that is essentially independent from boundaries such as environmental and operating conditions.As the emission-related certification process for EU-7/-VII applications is entirely based on PEMS-measurements in all kinds of real-world driving cycles, the intended OBM aspect is also entirely related to PEMS-based emission criteria, marginally reduced by physical constraints like realizing reliable operating conditions for installed sensors, like e.g., warm-up, linearization or dew point protection [1].Under the anticipated Euro 7/VII standards, vehicle emissions are considered as being generated by a single, holistic system, with tailpipe emissions generally understood to be below the limit, regardless of what technology package the powertrain contains. With a multitude of factors determining the actual emissions behavior of the application as well as the measuring accuracy, meeting the intended continuous emissions monitoring represents even in comparison to the strict, ultra-low emission limits, the dominating challenge in meeting the upcoming EU-7 applications. This is due to the extreme complexity of the requirement and the very sensitive trade-off between the adherence to the formulated legal OBM limits and the realization of undesired and unnecessary consequences of the monitoring system, impacting the robust all-day usability of the vehicle over the complete service.Facing these extreme challenges, the paper in hand aims to provide a clear starting point resp. an aligned base for solution finding and delivers already some initial thoughts for solution finding and initial descriptions of the mandatory steps forward for realization and implementation.