Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


GARCIA_ANDREW_MICHAEL_MS.pdf (4.29 MB)

ETD Abstract Container

Abstract Header

Feed-Forward Air-Fuel Ratio Control during Transient Operation of an Alternative Fueled Engine

Garcia, Andrew Michael
http://rave.ohiolink.edu/etdc/view?acc_num=osu1366034780

Abstract Details

2013, Master of Science, Ohio State University, Mechanical Engineering.
With the increasing government regulations for higher vehicle fuel economy and lower tailpipe emissions, today’s automotive engineers are pushed to develop advanced vehicles. Further, due to the high prices of oil, the consumer market is demanding for more fuel efficient vehicles. To adapt to the increasing demands, automotive manufacturers have been investing in the research of advanced vehicle technologies. The work described in this thesis details the development of a methodology to improve the feed-forward air-fuel ratio control during transient operation of an alternative fueled engine. Due to transport delays between the induction of the air-fuel mixture into the cylinder and the reading of the combustion exhaust gases from the oxygen sensor, conventional feedback control cannot be accurately used in transient operation. Since the engine used in this thesis is port-fuel injected, the fuel injection is made a discrete amount of time before the intake valve opening. This gives the fuel time to vaporize in the intake runner before being inducted. Therefore, in order to achieve stoichiometric combustion, the amount of inducted air will have to be determined a discrete amount of time into the future. This work outlines the development of a control algorithm that improves the transient air-fuel ratio control by predicting the intake manifold air pressure forward in time. Using model-based calibration techniques and engine dynamometer data, an intake manifold model was created. Coupling this model with a Forward Euler approximation, a predictive intake manifold pressure algorithm was developed. Adaptive models were implemented into the control algorithm to account for day-to-day variations in engine operation as well as calibration errors in the intake manifold model. The algorithm was verified in software validation with a mean value engine model and hardware validation in the engine dynamometer test cell. With the implementation of the predictive control algorithm, there was a vast improvement in air-fuel ratio control performance over the engine’s previous control strategy. Oxygen sensor results showed a significant reduction in deviations from stoichiometric combustion, allowing the three-way catalyst to operate in its most efficient range. The research detailed in this thesis shows the effectiveness of using a model-based approach to air-fuel ratio control and the importance of adaptive algorithms for day-to-day changes in engine operation.
Shawn Midlam-Mohler, Dr. (Advisor)
Giorgio Rizzoni, Dr. (Committee Member)
149 p.
Automotive Engineering; Mechanical Engineering
air-fuel ratio control; tailpipe emissions reduction; feed-forward air-fuel ratio control; model-based calibration; intake manifold modeling; Forward Euler approximation

Recommended Citations

Citations

  • Garcia, A. M. (2013). Feed-Forward Air-Fuel Ratio Control during Transient Operation of an Alternative Fueled Engine [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366034780

    APA Style (7th edition)

  • Garcia, Andrew. Feed-Forward Air-Fuel Ratio Control during Transient Operation of an Alternative Fueled Engine. 2013. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1366034780.

    MLA Style (8th edition)

  • Garcia, Andrew. "Feed-Forward Air-Fuel Ratio Control during Transient Operation of an Alternative Fueled Engine." Master's thesis, Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366034780

    Chicago Manual of Style (17th edition)

osu1366034780
2,459
© 2013, all rights reserved.
This open access ETD is published by The Ohio State University and OhioLINK.