摘要 |
A combustion state detection apparatus includes an ion detection device that detects ions generated in a combustion chamber, an end detection device that detects ion signal end timing after spark timing obtained from the ion detection device, and a combustion diagnosis device that sets comparative timing to be compared with the end timing to determine abnormal combustion when the end timing is advanced from the comparative timing. The diagnosis device sets a smoothed value smoothed using various ion signal end timing values to set a ratio of the smoothed value and the spark timing and sets the comparative timing by making the ratio variable at predetermined timing with respect to the smoothed value. Hence, abnormal combustion in the internal combustion engine can be detected without causing a change in detection accuracy even with a change in calibration or environment and matching man hours for abnormal combustion detection can be reduced. |