Integrated fuel catalyst monitor
AssigneeFord Global Technologies, LLC
InventorsPankaj Kumar, Imad Hassan Makki, Brent Edward Sealy, Michael Casedy
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Abstract
A method is provided for monitoring an emission control device coupled to an engine. In one example approach, the method comprises, following a deceleration fuel shut-off (DFSO) duration, indicating degradation of an emission device based on an amount of rich products required to cause a sensor to become richer than a first threshold, the indicating carried out when DFSO duration is greater than a second threshold. The method also comprises an integration which is based on inlet air-fuel ratio, the integration starting only after a pre-catalyst sensor reaches stoichiometry.
Claims20
A method for an engine, comprising:
- following a deceleration fuel shut-off (DFSO) duration,
- indicating degradation of an emission device based on an amount of rich products required to cause a sensor to become richer than a first threshold, the indicating carried out when DFSO duration is greater than a second threshold, an integration based on inlet air-fuel ratio starting only after the inlet air-fuel ratio reaches stoichiometry.
A method for an engine, comprising:
- computing a total fuel mass injected following a deceleration fuel shut-off (DFSO) event, the computing including an integration based on an air mass flow and an air-fuel ratio from a first time corresponding to when a first exhaust gas sensor indicates stoichiometry until a second time when a second exhaust gas sensor undergoes a switch;
- and
- indicating degradation of a catalyst based on the total fuel mass.
A system, comprising:
- an engine coupled to an exhaust system including an emission control device;
- a first exhaust gas sensor positioned in the exhaust system upstream of the emission control device;
- a second exhaust gas sensor coupled downstream of a volume of catalyst material of the emission control device;
- a controller with computer-readable instructions stored in non-transitory memory for:
- initiating a deceleration fuel shut-off (DFSO) based on an engine operating condition;
- following the DFSO, initiating fueling in response to a driver tip-in;
- following the driver tip-in, estimating a total amount of fuel mass delivered from when the first exhaust gas sensor attains stoichiometry to a switch of the second exhaust gas sensor;
- applying the estimated total amount of fuel mass to a support vector machine to generate a classification output;
- and
- indicating catalyst degradation based on the classification output.
Dependencies are inferred from the claim text.