DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Next-Cycle Optimal Fuel Control for Cycle-to-Cycle Variability Reduction in EGR-Diluted Combustion

Abstract

Dilute combustion using exhaust gas recirculation (EGR) is a cost-effective method for increasing engine efficiency. At high EGR levels, however, its efficiency benefits diminish as cycle-to-cycle variability (CCV) intensifies. Here, cycle-to-cycle fuel control was used to reduce CCV by injecting additional fuel in operating conditions with sporadic misfires and partial burns. An optimal control policy was proposed that utilizes 1) a physics-based model that tracks in-cylinder gas composition and 2) a one-step-ahead prediction of the combustion efficiency based on a kernel density estimator. The optimal solution, however, presents a tradeoff between the reduction in combustion CCV and the increase in fuel injection quantity required to stabilize the charge. Such a tradeoff can be adjusted by a single parameter embedded in the cost function. Simulation results indicated that combustion CCV can be reduced by as much as 65% by using at most 1% additional fuel. Although the control design presented here does not include fuel trim to maintain λ=1 for three-way catalyst compatibility, it is envisioned that this approach would be implemented alongside such an external controller, and the theoretical contribution presented here provides a first insight into the feasibility of CCV control using fuel injection.

Authors:
ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1]; ORCiD logo [1];  [1]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1756233
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
IEEE Control Systems Letters
Additional Journal Information:
Journal Volume: 0; Journal Issue: 0; Journal ID: ISSN 2475-1456
Publisher:
IEEE
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; automotive control; energy systems; grey-box modeling; stochastic optimal control

Citation Formats

Maldonado Puente, Bryan, Kaul, Brian, Schuman, Catherine, Young, Steven, and Mitchell, Parker. Next-Cycle Optimal Fuel Control for Cycle-to-Cycle Variability Reduction in EGR-Diluted Combustion. United States: N. p., 2020. Web. doi:10.1109/lcsys.2020.3046433.
Maldonado Puente, Bryan, Kaul, Brian, Schuman, Catherine, Young, Steven, & Mitchell, Parker. Next-Cycle Optimal Fuel Control for Cycle-to-Cycle Variability Reduction in EGR-Diluted Combustion. United States. https://doi.org/10.1109/lcsys.2020.3046433
Maldonado Puente, Bryan, Kaul, Brian, Schuman, Catherine, Young, Steven, and Mitchell, Parker. Tue . "Next-Cycle Optimal Fuel Control for Cycle-to-Cycle Variability Reduction in EGR-Diluted Combustion". United States. https://doi.org/10.1109/lcsys.2020.3046433. https://www.osti.gov/servlets/purl/1756233.
@article{osti_1756233,
title = {Next-Cycle Optimal Fuel Control for Cycle-to-Cycle Variability Reduction in EGR-Diluted Combustion},
author = {Maldonado Puente, Bryan and Kaul, Brian and Schuman, Catherine and Young, Steven and Mitchell, Parker},
abstractNote = {Dilute combustion using exhaust gas recirculation (EGR) is a cost-effective method for increasing engine efficiency. At high EGR levels, however, its efficiency benefits diminish as cycle-to-cycle variability (CCV) intensifies. Here, cycle-to-cycle fuel control was used to reduce CCV by injecting additional fuel in operating conditions with sporadic misfires and partial burns. An optimal control policy was proposed that utilizes 1) a physics-based model that tracks in-cylinder gas composition and 2) a one-step-ahead prediction of the combustion efficiency based on a kernel density estimator. The optimal solution, however, presents a tradeoff between the reduction in combustion CCV and the increase in fuel injection quantity required to stabilize the charge. Such a tradeoff can be adjusted by a single parameter embedded in the cost function. Simulation results indicated that combustion CCV can be reduced by as much as 65% by using at most 1% additional fuel. Although the control design presented here does not include fuel trim to maintain λ=1 for three-way catalyst compatibility, it is envisioned that this approach would be implemented alongside such an external controller, and the theoretical contribution presented here provides a first insight into the feasibility of CCV control using fuel injection.},
doi = {10.1109/lcsys.2020.3046433},
journal = {IEEE Control Systems Letters},
number = 0,
volume = 0,
place = {United States},
year = {Tue Dec 22 00:00:00 EST 2020},
month = {Tue Dec 22 00:00:00 EST 2020}
}