Challenges with On Board Monitoring

The upcoming Euro 7 regulation includes a proposal for On Board Monitoring, or OBM, to continuously monitor vehicles for emissions conformance. OBM relies on feedback from sensors and models to identify high emitting vehicles, which poses many challenges. Sensors are not commercially available for all emissions constituents, and the accuracy of commercially available sensors is not capable enough for in use compliance determination. On board emissions models also do not currently have enough fidelity to determine in use compliance and implementation of models is complicated. The stack up of multi-component deterioration leading to an emissions exceedance is possible but also infeasible to detect using available sensors and models. The presentation will review what is being promulgated elsewhere in regard to using on-board sensors to directly measure pollutants such as CARB�s �REAL NOx Tracking� system. Meanwhile US EPA�s proposed �Health Monitors� seek to provide vehicle owners warning of impending failure. EPA�s SCR inducement seeks to lessen inducements by taking action only when emissions are verified to be out of control. The difficulties in servicing vehicles will be reviewed for system monitors which drove increased pinpointing requirements within CARB�s OBD regulations in direct opposition to the OBM concept. To conclude, more feasible alternatives to the OBM concept will be presented.