Method and device for examining an exhaust gas sensor
AssigneeContinental Automotive GmbH
InventorsMuammer Kilinc, Tim Walde
Life of this patent
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Abstract
A first voltage (V1) is detected between an auxiliary pump electrode and a reference electrode of an exhaust gas sensor, and a target diagnosis value (SDIAG) is determined as a function of the detected first voltage (V1). A measured current (Im) is detected between a measurement electrode and a second main pump electrode of the exhaust gas sensor, said measured current being set up as the pump current by regulating a second voltage between the measurement electrode and the reference electrode to a pre-defined voltage. An actual diagnosis value (IDIAG) is determined as a function of the detected measured current (Im). An error (ERR) of the exhaust gas sensor is recognized depending on the target diagnosis value (SDIAG) and the actual diagnosis value (IDIAG).
Claims11
A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising:
- sensing a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode;
- determining a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and adding a predefined shift value to the resulting value, wherein the predefined shift value is determined as a function of a calibration of the exhaust gas sensor;
- sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage, and determining an actual diagnostic value as a function of the sensed measuring current;
- and
- detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.
A device for testing an exhaust gas sensor,
- the exhaust gas sensor having
- a first chamber,
- a second chamber,
- a first diffusion barrier separating the first and second chambers, and
- a second diffusion barrier forming a gas inlet of the first chamber,
- the first chamber having a first main pump electrode and the second chamber has a measuring electrode and an auxiliary pump electrode, and
- a second main electrode and a reference electrode being disposed outside of the first and second chambers,
- the device being configured to:
- sense a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode and
- determine a set point diagnostic value as a function of the sensed first voltage multiplied by a predefined factor and the resulting value being added to a predefined shift value, wherein the predefined shift value is determined as a function of a calibration of the exhaust gas sensor,
- sense a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage, and
- determine an actual diagnostic value as a function of the sensed measuring current, and detect a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.
A method for testing an exhaust gas sensor having a first chamber, a second chamber, a first diffusion barrier separating the first and second chambers, and a second diffusion barrier forming a gas inlet of the first chamber, the first chamber having first main pump electrode, the second chamber having a measuring electrode and an auxiliary pump electrode, and a second main pump electrode and a reference electrode being disposed outside of the first and second chambers, said method comprising:
- sensing a first voltage as a predefined voltage between the auxiliary pump electrode and the reference electrode;
- determining a set point diagnostic value based at least in part on a first current between the measuring electrode and the second main pump electrode at the first voltage;
- sensing a measuring current between the measuring electrode and the second main pump electrode, the measuring current being set as a pump current by adjusting a second voltage between the measuring electrode and the reference electrode to the predefined voltage;
- determining an actual diagnostic value as a function of the sensed measuring current;
- and
- detecting a fault in the exhaust gas sensor as a function of the set point diagnostic value and the actual diagnostic value.
Dependencies are inferred from the claim text.