Method of checking the performance of catalysts in internal-combustion engines
AssigneesDr. Ing. h.c.F. Porsche Aktiengesellschaft, Audi AG, Bayerische Motoren Werke Aktiengesellschaft, Volkswagen Aktiengesellschaft, DaimlerChrysler AG
InventorsPaul Kueper, Stefan Peter, Jens Mueller
Life of this patent
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Abstract
A process is suggested for checking the catalyst performance in internal-combustion engines, in which by means of detected operating parameters of the internal-combustion engine similar operating conditions are determined. It is suggested to compute from a defined number of measured exhaust gas values during a similar operating condition a statistically backed average exhaust gas value and compare it with a permissible exhaust gas value stored for this operating condition, so that a defective catalyst is recognized in the event of a deviation of the actually determined exhaust gas value from the permissible exhaust gas value.
Claims19
A method of checking the operation of a catalyst arranged in an exhaust gas pipe of an internal-combustion engine, a sensor being arranged behind the catalyst and detecting exhaust gas values, the method comprising the acts of:
- determining similar operating conditions of the internal-combustion engine via detected operating parameters;
- forming a statistically backed total average exhaust gas value from a defined number of exhaust gas values during a particular similar operating condition;
- comparing said statistically backed total average exhaust gas value with a maximally permissible exhaust gas value stored in a memory for the particular similar operating condition;
- recognizing the catalyst is defective when the statistically backed total average exhaust gas value exceeds the permissible exhaust gas value;
- checking a result of the comparison of the statistically backed total average exhaust gas value with the permissible exhaust gas value stored in the memory via a second sensor arranged in front of the catalyst and via an analysis of a conversion rate with respect to plausibility of the statistically backed total average exhaust gas value.
Dependencies are inferred from the claim text.