Methods and systems for humidity detection via an exhaust gas sensor
AssigneeFord Global Technologies, LLC
InventorsGopichandra Surnilla, Richard E. Soltis, Timothy Schram, Timothy Joseph Clark, Evangelos Skoures
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Abstract
Various methods and system are described for determining ambient humidity via an exhaust gas sensor disposed in an exhaust system of an engine. In one example, a reference voltage of the sensor is modulated between a first and second voltage during non-fueling conditions of the engine. The ambient humidity is determined based on an average change in pumping current while the voltage is modulated.
Claims20
A method for an engine system, comprising:
- during engine non-fueling conditions, where at least one intake valve and one exhaust valve are operating and a duration since fuel shut off is less than a threshold duration:
- modulating a reference voltage of an exhaust gas sensor between a first reference voltage and a second reference voltage;
- generating an indication of ambient humidity based on an average change in pumping current of the sensor during the modulating;
- and
- during subsequent engine fueling conditions, adjusting an engine actuator based on the indication of ambient humidity.
A method for an exhaust gas sensor coupled in an exhaust passage of an engine, comprising:
- during engine non-fueling conditions, where at least one intake valve and one exhaust valve are operating:
- during a first condition when a duration since fuel shut off is less than a threshold duration:
- modulating a reference voltage between a first voltage and a second voltage;
- determining a first indication of ambient humidity based on an average change in pumping current during the modulating;
- and
- during a second condition when the duration since fuel shut off is greater than the threshold duration:
- increasing the reference voltage to a threshold voltage and not modulating the reference voltage;
- and
- determining a second indication of ambient humidity based on a change in pumping current upon increasing the reference voltage to the second voltage;
- and
- during subsequent engine fueling conditions, adjusting an engine actuator based on the ambient humidity.
A system, comprising:
- an engine with an exhaust system;
- an exhaust gas oxygen sensor disposed in the exhaust system;
- a control system in communication with the sensor, the control system including non-transitory instructions to:
- shut off engine fueling;
- and
- following shutting off engine fueling and before a threshold duration since fuel shut off, modulate a reference voltage of the sensor between a first voltage and a second voltage, and generate a first indication of ambient humidity based on a change in pumping current responsive to the modulation of the reference voltage;
- following shutting off engine fueling and after the threshold duration since fuel shut off, increase the reference voltage to the second voltage and not modulate the reference voltage, and generate a second indication of ambient humidity based on a change in pumping current responsive to the change in reference voltage;
- and, during subsequent engine fueling conditions, adjust one or more engine operating parameters based on the ambient humidity.
Dependencies are inferred from the claim text.