A particle filter for ammonia coverage ratio and input simultaneous estimations in Diesel-engine SCR system

PLoS One. 2018 Feb 6;13(2):e0192217. doi: 10.1371/journal.pone.0192217. eCollection 2018.


As NOx emissions legislation for Diesel-engines is becoming more stringent than ever before, an aftertreatment system has been widely used in many countries. Specifically, to reduce the NOx emissions, a selective catalytic reduction(SCR) system has become one of the most promising techniques for Diesel-engine vehicle applications. In the SCR system, input ammonia concentration and ammonia coverage ratio are regarded as essential states in the control-oriental model. Currently, an ammonia sensor placed before the SCR Can is a good strategy for the input ammonia concentration value. However, physical sensor would increase the SCR system cost and the ammonia coverage ratio information cannot be directly measured by physical sensor. Aiming to tackle this problem, an observer based on particle filter(PF) is investigated to estimate the input ammonia concentration and ammonia coverage ratio. Simulation results through the experimentally-validated full vehicle simulator cX-Emission show that the performance of observer based on PF is outstanding, and the estimation error is very small.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ammonia / analysis*
  • Catalysis
  • Gasoline / analysis*
  • Models, Theoretical
  • Oxidation-Reduction
  • Vehicle Emissions / analysis*


  • Gasoline
  • Vehicle Emissions
  • Ammonia

Grant support

This work is supported by National Natural Science Foundation of China, (http://www.nsfc.gov.cn), grant number: 51576011 to SCY. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.