| NSF Org: |
CMMI Division of Civil, Mechanical, and Manufacturing Innovation |
| Recipient: |
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| Initial Amendment Date: | September 19, 2012 |
| Latest Amendment Date: | August 8, 2017 |
| Award Number: | 1235461 |
| Award Instrument: | Standard Grant |
| Program Manager: |
Irina Dolinskaya
idolinsk@nsf.gov (703)292-7078 CMMI Division of Civil, Mechanical, and Manufacturing Innovation ENG Directorate for Engineering |
| Start Date: | October 1, 2012 |
| End Date: | September 30, 2018 (Estimated) |
| Total Intended Award Amount: | $199,999.00 |
| Total Awarded Amount to Date: | $199,999.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
4300 MARTIN LUTHER KING BLVD HOUSTON TX US 77204-3067 (713)743-5773 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
4800 Calhoun Rd Houston TX US 77204-4006 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | CONTROL SYSTEMS |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.041 |
ABSTRACT
The research objective of this award is to develop methods for the feedback control of the coupled engine and catalyst systems in automotive vehicles seeking to further reduce fuel consumption and harmful emissions. The engine and the exhaust catalyst sub-systems are highly interdependent based on coupled operational constraints and interconnected dynamics with conflicting objectives. The research will employ first-principles and phenomenological models of the engine and the catalyst to address the air and fuel mixture regulation that dictates fuel consumption and exhaust emissions from the after-treatment system. Challenges to overcome are the varying transport delays in the feedback loop, the varying sampling rates due to event-based sampling and the highly nonlinear and varying dynamic of the coupled engine/catalyst system. A linear parameter varying feedback control methodology that is appropriately modified to address the above challenges will be investigated to regulate the engine air/fuel mixture based on post-catalyst sensor measurements for varying engine speed and load conditions.
Is successful, the results of this research would lead to improvements in fuel economy and reduced harmful emissions from automotive vehicles. Proposed cooperation with the automotive industry will seek to transfer research results to technology that could impact future production vehicles. The proposed modeling and control methodology could benefit the other coupled complex systems, such as, material processing and energy conversion systems. The project has an educational goal of promoting inter-disciplinary teaching and research on electro-mechanical and chemical reaction systems and producing engineers that are diverse and pursue the benefit of society.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Future automotive internal combustion engines will have to achieve extremely demanding feedback control and diagnostics requirements to drastically minimize consumed fuel and keeping harmful emissions to practically zero. The automotive engine and exhaust aftertreatment systems are highly interdependent based on coupled operational constraints and interconnected dynamics with conflicting objectives. A main challenge in the precise regulation of the integrated engine and aftertreatment systems is the large and variable time-delay in the feedback loop due to the position of the exhaust gas oxygen sensor downstream the catalyst. To achieve the stated goal of integrated engine and catalyst control and diagnostics the project has accomplish discoveries on (i) the low-order first-principles modeling of the automotive exhaust three-way catalytic converter (TWC) and (ii) the systematic model-based internal combustion engine regulation subject to operating variability, variable sampling rate and large variable measurement time-delays. Low order TWC models have been developed and validated to assist in control design and to evaluate emissions. The first-principles dynamic modelling of the TWC was obtained formulating the exhaust reaction species and energy balances in the catalyst to determine dynamic characteristics of exhaust gases, temperature and oxygen storage/release and utilizing averaging for model approximation. The model has been validated via comparisons with a detailed diffusion/reaction catalyst model and with experimental data. Parameter varying feedback control laws have been developed to address the precise engine air/fuel ratio (AFR) regulation using a linear parameter varying (LPV) formulation that explicitly takes into account system uncertainty and varying input delays in the feedback loop. The method can handle fast delay changes resulting from rapid engine speed and exhaust mass air flow variations. Purge events that constitute a significant disturbance in the air-fuel ratio dynamics have been characterized in a linear parameter varying model representation of the evaporative system and compensated via a feedforward control strategy. The closed-loop validation of the engine/catalyst controller performance and robustness while meeting AFR tracking, TWC oxygen storage control and disturbance rejection requirements has been accomplished using simulation studies. The project has been conducted in partnership with automotive companies ensuring the relevance and practicality of the findings. The project has educated mechanical engineering and chemical engineering graduate students providing an interdisciplinary knowledge base and expertise promoting engineers that are diverse and seeking the benefit of society.
Last Modified: 12/20/2018
Modified by: Karolos M Grigoriadis
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