Engine control advantageously using humidity
AssigneeFord Global Technologies, LLC
InventorMichael J. Cullen
Life of this patent
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Abstract
A system and method for utilizing a humidity sensor with an internal combustion engine of a vehicle is described. Specifically, information from the humidity sensor is used to adjust a desired air-fuel ratio to reduce engine misfire while improving vehicle fuel economy. Further, such information is also used to adjust timing and/or lift of the valve in the engine cylinder. Finally, diagnostic routines are also described.
Claims9
A method for adjusting engine operation of a vehicle, the method comprising:
- determining a parameter indicative of ambient humidity outside of the vehicle;
- determining a desired lean air-fuel ratio based at least on an engine operating condition;
- calculating an air-fuel ratio adjustment based on said parameter to reduce said desired lean air-fuel ratio toward stoichiometry;
- and
- limiting said adjustment of said desired lean air-fuel ratio based on said humidity parameter to approximately a stoichiometric air-fuel ratio.
A computer storage medium having instructions encoded therein for controlling an engine of a powertrain in a vehicle on the road, said medium comprising:
- code for determining a parameter indicative of ambient humidity outside of the vehicle;
- code for determining a desired lean air-fuel ratio based at least on an engine operating condition;
- code for calculating an air-fuel ratio adjustment based on said parameter to reduce said desired lean air-fuel ratio toward stoichiometry;
- and
- code for limiting said adjustment of said desired lean air-fuel ratio based on said humidity parameter to substantially a stoichiometric air-fuel ratio.
Dependencies are inferred from the claim text.