Method for detecting flow-reducing changes in an exhaust-gas catalyst body
AssigneeDaimlerChrysler AG
InventorsPeter Hohner, Jörg Miroll, Hartung Wilstermann
Life of this patent
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Abstract
A method for detecting flow-reducing changes in an exhaust-gas catalyst body is provided. The method includes measuring the ion-current signal from an ion-current probe in an internal combustion engine and monitoring the signal to determine whether its signal strength for a particular operating cycle falls below a minimum strength which can be specified as a function of the engine operating state. The method also include providing warning information to the control system when such an event occurs. The method further includes a variety of embodiments used to determine whether the ion current signal falls below a minimum strength.
Claims13
A method for detecting flow-reducing changes in an exhaust-gas catalyst body of an exhaust-gas purification system during the operation of an associated internal combustion engine with at least one engine cylinder, said at least one engine cylinder having a plurality of operating conditions that produces exhaust gas that impinges upon the exhaust-gas catalyst body, said at least one engine cylinder includes an ion-current measuring probe associated therewith that produces an ion-current signal, said method comprising:
- identifying a minimum strength desired for said ion-current signal;
- monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with said at least one engine cylinder;
- comparing said strength of said ion-current signal to said minimum strength of said ion-current signal;
- and
- providing a warning indicating a flow-reducing change in said catalyst body when said strength of said ion-current falls below said minimum strength.
A method for detecting flow-reducing changes in an exhaust-gas catalyst body of an exhaust-gas purification system during the operation of an associated internal combustion engine with at least one engine cylinder, said at least one engine cylinder having a plurality of operating conditions that produces exhaust gas that impinges upon the exhaust-gas catalyst body, said at least one engine cylinder includes an ion-current measuring probe associated therewith that produces an ion-current signal, said method comprising:
- identifying a minimum integration value desired for said ion-current signal;
- monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with said at least one engine cylinder over an operating cycle of said at least one engine cylinder;
- integrating said ion-current signal over said operating cycle of said at least one engine cylinder to produce an integrated value;
- and
- comparing said integrated value to said minimum integration value;
- and
- providing a warning indicating a flow-reducing change in said catalyst body when said integrated value falls below said minimum integration value for at least one operating cycle.
A method for detecting flow-reducing changes in an exhaust-gas catalyst body of an exhaust-gas purification system during the operation of an associated internal combustion engine with at least one engine cylinder, said at least one engine cylinder having a plurality of operating conditions that produces exhaust gas that impinges upon the exhaust-gas catalyst body, said at least one engine cylinder includes an ion-current measuring probe associated therewith that produces an ion-current signal, said method comprising:
- identifying a evaluation range of a operating cycle of said at least one engine cylinder;
- identifying a minimum strength desired for said ion-current signal during said evaluation range;
- monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with said at least one engine cylinder;
- comparing said strength of said ion-current signal during said evaluation range to said minimum strength of said ion-current signal;
- and
- providing a warning indicating a flow-reducing change in said catalyst body when said strength of said ion-current falls below said minimum strength.
A method for detecting flow-reducing changes in an exhaust-gas catalyst body of an exhaust-gas purification system during the operation of an associated internal combustion engine with at least one engine cylinder, said at least one engine cylinder having a plurality of operating conditions that produces exhaust gas that impinges upon the exhaust-gas catalyst body, said at least one engine cylinder includes an ion-current measuring probe associated therewith that produces an ion-current signal, said method comprising:
- identifying a minimum peak-value amplitude value desired for said ion-current signal;
- monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with said at least one engine cylinder over an operating cycle of said at least one engine cylinder;
- identifying a peak-value amplitude of said ion-current signal over said operating cycle of said at least one engine cylinder;
- and
- comparing said peak-value amplitude to said minimum peak-value amplitude;
- and
- providing a warning indicating a flow-reducing change in said catalyst body when said peak-value amplitude falls below said minimum peak value amplitude for at least one operating cycle.
A method for detecting flow-reducing changes in an exhaust-gas catalyst body of an exhaust-gas purification system during the operation of an associated internal combustion engine having at least one engine cylinder associated with a first exhaust-gas catalyst body and at least one engine cylinder associated, each of said engine cylinders having a plurality of operating conditions that produces exhaust gas that impinges upon its associated exhaust-gas catalyst body, said at least one engine cylinder associated with said first exhaust-gas catalyst body includes an ion-current measuring probe associated therewith that produces an ion-current signal, said at least one engine cylinder associated with said second exhaust-gas catalyst body includes an ion-current measuring probe associated therewith that produces an ion-current signal said method comprising:
- monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with a first exhaust-gas catalyst body;
- monitoring said strength of said ion-current signal produced by said ion-current measuring probe associated with a second exhaust-gas catalyst body;
- and
- providing a warning indicating a flow-reducing change in one of said catalyst bodies when said strength of said ion-current associated with said first exhaust-gas catalyst body and said strength of said ion-current associated with said second exhaust-gas catalyst body differ by more than a predetermined amount.
Dependencies are inferred from the claim text.