| 摘要 |
An output of a knock sensor is A/D converted in a specified knock determination range. In a time-frequency analysis part, data of frequency, time, and vibration intensity are extracted at the same time from the knock sensor output signal and the time-varying patterns of vibration intensities in multiple frequency ranges are extracted. An edge direction and an edge intensity are computed by an edge extraction processing. A correlation value expressing a correlation between time-varying patterns of vibration intensities in multiple frequency ranges and a reference model expressing the feature of knock is computed in a mutual correlation/knock determination part. The correlation value is compared with a determination threshold. When the correlation value is larger than the determination threshold, it is determined that knock is caused. When the correlation value is not larger than the determination threshold, it is determined that knock is not caused. |
