| 摘要 |
The invention relates to an arrangement for monitoring the performance loss of an oxygen probe arranged forward of a catalytic converter. The oxygen probe supplies an actual voltage U-ACT for a lambda controller for an internal combustion engine and the arrangement includes: a computation unit for computing the time-dependent mean value |U-ACT-U-DES | of the actual voltage U-ACT from a desired voltage U-DES; and, an evaluation unit for determining the performance loss of the oxygen probe on the basis of the time-dependent mean value. A simple method sequence which can be carried out with the above arrangement includes the step of deeming the probe to have an impermissibly high performance loss when the above-mentioned mean value drops below a threshold value. However, the quotient is preferably formed between the above-mentioned mean value and the mean value |FR-ACT-FR-DES| and the probe is deemed to have too great a performance loss when this quotient drops below a threshold value. The variable |FR-ACT-FR-DES| is the amount of the deviation of the output signal FR-ACT of the lambda controller from a desired value FR-DES. In this procedure, a very good signal/noise ratio is obtained which permits an especially reliable evaluation of the performance loss of the probe.
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