A study on in-cycle control of NOx using injection strategy with a fast cylinder pressure based emission model as feedback

Kenan Muric*, Ola Stenlaas, Per Tunestal, Bengt Johansson

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

16 Scopus citations


The emission control in heavy-duty vehicles today is based on predefined injection strategies and after-treatment systems such as SCR (selective catalytic reduction) and DPF (diesel particulate filter). State-of-the-art engine control is presently based on cycle-to-cycle resolution. The introduction of the crank angle resolved pressure measurement, from a piezo-based pressure sensor, enables the possibility to control the fuel injection based on combustion feedback while the combustion is occurring. In this paper a study is presented on the possibility to control NOx (nitrogen oxides) formation with a crank angle resolved NOx estimator as feedback. The estimator and the injection control are implemented on an FPGA (Field-Programmable Gate Array) to manage the inherent time constraints. The FPGA is integrated with the rest of the engine control system for injection control and measurement. Studies of injection strategies show that one of the feasible approaches, using a solenoid injector to control NOx, is a split-main injection based strategy. Results suggest that it is hard to control the NOx in a satisfactory manner. Really low injection pressures and long injection durations had to be applied to achieve control of the NO x formation. This also implies inherently high smoke emissions. The strategy allows NOx reduction but measurement and emission estimation results indicate that the delay between fuel injection and the maximum NO x concentration is too long. The NOx target value defined could never be satisfied using the feedback-based split-main injection strategy. Prediction-based feedback will be necessary to improve the control.

Original languageEnglish (US)
JournalSAE Technical Papers
StatePublished - 2013
EventSAE/KSAE 2013 International Powertrains, Fuels and Lubricants Meeting, FFL 2013 - Seoul, Korea, Republic of
Duration: Oct 21 2013Oct 23 2013

ASJC Scopus subject areas

  • Automotive Engineering
  • Safety, Risk, Reliability and Quality
  • Pollution
  • Industrial and Manufacturing Engineering


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