0
Research Papers

Oxygen Concentration Dynamic Model and Observer-Based Estimation Through a Diesel Engine Aftertreatment System

[+] Author and Article Information
Pingen Chen

 Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210chen.2554@osu.edu

Junmin Wang1

 Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210wang.1381@osu.edu

1

Corresponding author.

J. Dyn. Sys., Meas., Control 134(3), 031008 (Mar 27, 2012) (10 pages) doi:10.1115/1.4005508 History: Received April 19, 2011; Revised December 19, 2011; Published March 27, 2012; Online March 27, 2012

Due to the chemical reactions occurring inside the diesel oxidation catalysts (DOCs) and diesel particulate filters (DPFs) that are commonly equipped on diesel engines, the exhaust gas oxygen concentrations considerably vary through the aftertreatment systems. Oxygen concentration in exhaust gas is important for the performance of catalysts such as the NOx conversion efficiencies of the selective catalytic reduction systems and lean NOx traps. Moreover, in the presence of a low-pressure loop exhaust gas recirculation, the exhaust gas oxygen concentration after DPF also influences the in-cylinder combustion. From system control, estimation, and analysis viewpoints, it is thus imperative to have a control-oriented model to describe the oxygen concentration dynamics across the DOC and DPF. In this paper, a physics-based, lumped-parameter, control-oriented DOC–DPF oxygen concentration dynamic model was developed with a multi-objective optimization method and validated with the experimental data obtained on a medium-duty diesel engine equipped with a full suite of aftertreatment systems. Experimental results show that the model can well capture the oxygen dynamics across the diesel engine aftertreatment systems. As an application of the experimentally validated model, an observer was designed to estimate the DOC-out and DPF-out oxygen concentrations in real time. Experimental results show that the estimated states from the proposed observer can converge to the measured signals fastly and accurately.

Copyright © 2012 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Diesel engine and aftertreatment system setup

Grahic Jump Location
Figure 2

The schematic diagram of a diesel engine and its aftertreatment system

Grahic Jump Location
Figure 4

DPF CSTR model schematic diagram

Grahic Jump Location
Figure 5

Oxygen measurements from tests 2, 3, and 4

Grahic Jump Location
Figure 6

Engine speed and pedal profiles of test 2

Grahic Jump Location
Figure 7

DOC-out oxygen concentrations from model and test (engine speed: 750 to 2400 rpm)

Grahic Jump Location
Figure 8

DOC-out oxygen concentrations from model and test (engine speed: 2600 to 2900 rpm)

Grahic Jump Location
Figure 9

DOC-out oxygen concentrations from model and test (engine speed: 650 to 2600 rpm)

Grahic Jump Location
Figure 12

DPF-out oxygen concentrations from model and test (engine speed: 2600 to 2900 rpm)

Grahic Jump Location
Figure 13

Comparison of DOC-out oxygen measurement, model prediction, and estimation

Grahic Jump Location
Figure 14

Zoom-in estimation of high DOC-out oxygen concentration in the first 5 s

Grahic Jump Location
Figure 15

Zoom-in estimation of low DOC-out oxygen concentration from 200 s to 280 s

Grahic Jump Location
Figure 16

Comparison of DPF-out oxygen measurement, model prediction, and estimation

Grahic Jump Location
Figure 17

Zoom-in estimation of high DPF-out oxygen concentration in the first 5 s

Grahic Jump Location
Figure 18

Zoom-in estimation of low DPF-out oxygen concentration from 200 s to 280 s

Grahic Jump Location
Figure 10

DOC-out NO concentrations from model and test (engine speed: 750 to 2400 rpm)

Grahic Jump Location
Figure 11

DPF-out oxygen concentrations from model and test (engine speed: 750 to 2400 rpm)

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In