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AssigneeRobert Bosch GmbH
InventorsKersten Wehmeier, Michael Pfeil, Siyun Chu, Albrecht Clement
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A method for the dynamic monitoring of a first lambda probe arranged in an exhaust-gas duct of an internal combustion engine upstream of an exhaust-gas purification system. A period of an output signal of the first lambda probe is determined in a controller of the internal combustion engine, and a lambda regulating signal is determined from an output signal of a second lambda probe connected downstream of the exhaust-gas purification system. A first threshold value for a lengthening of the period of the output signal of the first lambda probe is predefined, in that a characteristic signal (46) is derived from the lambda regulating signal, in that a second threshold value for an inadmissible deviation of the characteristic signal (46) is predefined, and in that an inadmissible asymmetric delay of the first lambda probe is inferred if the lengthening of the period exceeds the first threshold value and the characteristic signal (46) deviates from the second threshold value outside predetermined limits.
A method for the dynamic monitoring of a first lambda probe arranged in an exhaust-gas duct of an internal combustion engine upstream of an exhaust-gas purification system, a period of an output signal of the first lambda probe is determined in a controller of the internal combustion engine, and a lambda regulating signal is determined from an output signal of a second lambda probe connected downstream of the exhaust-gas purification system, characterized in that a first threshold value for a lengthening of the period of the output signal of the first lambda probe is predefined, in that a characteristic signal (46) is derived from the lambda regulating signal, in that a second threshold value for an inadmissible deviation of the characteristic signal (46) is predefined, and in that an inadmissible asymmetric delay of the first lambda probe is inferred if the lengthening of the period exceeds the first threshold value and the characteristic signal (46) deviates from the second threshold value outside predetermined limits.
Device for the dynamic monitoring of a first lambda probe arranged in an exhaust-gas duct of an internal combustion engine upstream of an exhaust-gas purification system, a controller of the internal combustion engine configured to determine a period of an output signal of the first lambda probe, and a second lambda probe connected downstream of the exhaust-gas purification system for determining a lambda regulating signal, characterized in that the controller of the internal combustion engine determines an inadmissible asymmetrical delay of the first lambda probe exists based on a comparison of the period of the output signal of the first lambda probe with a threshold value and a comparison of a characteristic signal (46) determined from the lambda regulating signal with predefined threshold values.
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