| 摘要 |
The invention is directed to a method for detecting combustion misfires in an internal combustion engine having a crankshaft and a transducer wheel coupled to the crankshaft and a sensor. The combustion misfires are detected on the basis of a time-dependent trace of the rotational movement of the transducer wheel and the transducer wheel has predetermined segments which pass the sensor. In the method, a sensor is utilized to detect segment times in which the segments pass the sensor so that the sensor produces a sensor signal representing the segment times. The sensor signal is applied as an input signal to first and second lowpass filters mutually connected in parallel thereby obtaining first and second output signals which react with different speeds to changes in the input signal. The difference between the first and second output signals is formed and a measure is, in turn, formed for the changes of the difference. The measure is compared to a threshold value and a movement of the measure above the threshold value is evaluated as a misfire. |
