Model-based control system design in a urea-SCR aftertreatment system based on NH3 sensor feedback

  • M. DevarakondaEmail author
  • G. Parker
  • J. H. Johnson
  • V. Strots


This paper presents preliminary control system simulation results in a urea-selective catalytic reduction (SCR) aftertreatment system based on NH3 sensor feedback. A four-state control-oriented lumped parameter model is used to analyze the controllability and observability properties of the urea-SCR plant. A model-based estimator is designed via simulation and a control system is developed with design based on a sliding mode control framework. The control system based on NH3 sensor feedback is analyzed via simulation by comparing it to a control system developed based on NOx sensor feedback. Simulation results show that the NH3 sensor-based strategy performs very similarly in comparison to a NOx sensor-based strategy. The control system performance metrics for NOx index, urea index, urea usage, and NH3 slip suggest that the NOx sensor can be a potential alternative to a NOx sensor for urea-SCR control applications.

Key Words

Urea-SCR catalyst Model-based estimation Observer Control system design NH3 sensor Sliding mode control 


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Copyright information

© The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg 2009

Authors and Affiliations

  • M. Devarakonda
    • 1
    Email author
  • G. Parker
    • 1
  • J. H. Johnson
    • 1
  • V. Strots
    • 2
  1. 1.ME-EM DepartmentMichigan Technological UniversityHoughtonUSA
  2. 2.Advanced Aftertreatment TechnologiesNavistar IncMelrose ParkUSA

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