Adaptive Air Fuel Ratio Optimisation of a Lean Burn SI Engine 961156
An adaptive air fuel ratio (AFR) control system has been implemented on a modern high performance fuel injected four cylinder engine. A pressure transducer in the combustion chamber is used to measure the indicated mean effective pressure (IMEP) for efficiency and cyclic variability feedback. The controller tunes the relative AFR, λ, in the range λ = 1 to λ = 1.5, to maximise the thermal efficiency in real time. The system adaptively accounts for changes in operating conditions such as ambient temperatures and user demands. The IMEP feedback allows the closed loop control system to update every few revolutions with short tune in times in the order of seconds. Open and closed loop test results are presented, demonstrating the incremental efficiency gains over fixed or mapped AFR control. The system continually adjusts the fuelling for maximum efficiency given its constraints and provides a basis for optimisation of future lean burn technologies.
Citation: Dingli, R., Watson, H., Palaniswami, M., and Glasson, N., "Adaptive Air Fuel Ratio Optimisation of a Lean Burn SI Engine," SAE Technical Paper 961156, 1996, https://doi.org/10.4271/961156. Download Citation
Author(s):
Robert J. Dingli, Harry C. Watson, Marimuthu Palaniswami, Neil Glasson
Affiliated:
University of Melbourne
Pages: 10
Event:
International Fuels & Lubricants Meeting & Exposition
ISSN:
0148-7191
e-ISSN:
2688-3627
Also in:
Combustion and Emissions in SI Engines-SP-1177
Related Topics:
Lean burn engines
Air / fuel ratio
Combustion chambers
Control systems
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