Abstract
NOx emissions abatement is one of the main challenges for diesel engine manufacturers, as far as the new pollutant emissions laws pretend further reductions with respect to the previous ones. The problem of the current automotive emission models is that they are open-loop suffering from drift problems; emission production measurement is not an standard in current production vehicles as far as emission sensors have reliability, cost and dynamic response limitations. This paper makes use of a ZrO2-based NOx sensor output and a simple NOx model development that in combination with Kalman filtering techniques allow to obtain a reliable fast NOx estimate that can be used for control, diagnosing or calibration purposes.
Keywords: combustion engine; NOx model; ZrO2 sensor; Kalman filter; engine control.