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A Fast Physical NOx Model Implemented on an Embedded System

Wilhelmsson, Carl LU ; Tunestål, Per LU ; Widd, Anders LU and Johansson, Rolf LU (2009) 2009 IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling In [Host publication title missing]
Abstract
This paper offers a two-zone, physical, NOx model with low computational cost, implemented in C on an embedded system. The model is able to compute NOx-emission formation with high time resolution during an engine cycle. To do this the model takes cylinder pressure and injected fuel amount as inputs and produces NO concentration as output. The model as such is not new, nevertheless the physical background of the model as well as the equations upon which the model is based had to be briefly described to facilitate the understanding of the subsequent work. The main part of the paper is devoted to the process of developing an algorithm implementing the described model, techniques used and issues encountered are described. The resulting... (More)
This paper offers a two-zone, physical, NOx model with low computational cost, implemented in C on an embedded system. The model is able to compute NOx-emission formation with high time resolution during an engine cycle. To do this the model takes cylinder pressure and injected fuel amount as inputs and produces NO concentration as output. The model as such is not new, nevertheless the physical background of the model as well as the equations upon which the model is based had to be briefly described to facilitate the understanding of the subsequent work. The main part of the paper is devoted to the process of developing an algorithm implementing the described model, techniques used and issues encountered are described. The resulting algorithm was implemented in C and tested on an embedded ARM processor. For the sake of implementation, parts of the algorithm had to be pre-computed and stored in tables, allowing significant acceleration of the computations. Since the model is non-linear, exponentially spaced tables had to be developed in order to successfully tabulate the parts needed without consuming too much memory. Much of the methods presented are also applicable in a variety other applications when it is desirable to implement fast versions of complex algorithms and models. The outcome regarding computation speed and memory needed is discussed. The final result is a low-cost NOx model, which is able to compute several orders of magnitude faster than NOx models known so far, implemented in C on an embedded system. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Nitrogen Oxides, Emissions, Air pollution, Algorithms, Physical model, Mathematical model, FPGA, Field Programmable Gate Arrays, Embedded Systems, Micro-controllers, NO, NOx, Engine, Diesel Engine, Internal Combustion Engine.
in
[Host publication title missing]
pages
9 pages
publisher
IFAC
conference name
2009 IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling
external identifiers
  • scopus:80051541639
language
English
LU publication?
yes
id
e9644cf8-fee4-4773-8a0b-8c82e7a2ae19 (old id 1514704)
date added to LUP
2010-01-07 11:14:28
date last changed
2017-03-26 04:36:32
@inproceedings{e9644cf8-fee4-4773-8a0b-8c82e7a2ae19,
  abstract     = {This paper offers a two-zone, physical, NOx model with low computational cost, implemented in C on an embedded system. The model is able to compute NOx-emission formation with high time resolution during an engine cycle. To do this the model takes cylinder pressure and injected fuel amount as inputs and produces NO concentration as output. The model as such is not new, nevertheless the physical background of the model as well as the equations upon which the model is based had to be briefly described to facilitate the understanding of the subsequent work. The main part of the paper is devoted to the process of developing an algorithm implementing the described model, techniques used and issues encountered are described. The resulting algorithm was implemented in C and tested on an embedded ARM processor. For the sake of implementation, parts of the algorithm had to be pre-computed and stored in tables, allowing significant acceleration of the computations. Since the model is non-linear, exponentially spaced tables had to be developed in order to successfully tabulate the parts needed without consuming too much memory. Much of the methods presented are also applicable in a variety other applications when it is desirable to implement fast versions of complex algorithms and models. The outcome regarding computation speed and memory needed is discussed. The final result is a low-cost NOx model, which is able to compute several orders of magnitude faster than NOx models known so far, implemented in C on an embedded system.},
  author       = {Wilhelmsson, Carl and Tunestål, Per and Widd, Anders and Johansson, Rolf},
  booktitle    = {[Host publication title missing]},
  keyword      = {Nitrogen Oxides,Emissions,Air pollution,Algorithms,Physical model,Mathematical model,FPGA,Field Programmable Gate Arrays,Embedded Systems,Micro-controllers,NO,NOx,Engine,Diesel Engine,Internal Combustion Engine.},
  language     = {eng},
  pages        = {9},
  publisher    = {IFAC},
  title        = {A Fast Physical NOx Model Implemented on an Embedded System},
  year         = {2009},
}