| 摘要 |
PROBLEM TO BE SOLVED: To detect vibration resulting from knocking by suppressing noise. SOLUTION: An engine ECU 200 comprises a band pass filter (1) 410, a band pass filter (2) 420, and a band pass filter (3) 430. The band pass filter (1) 410 extracts only the vibration of a first frequency band A from a vibration detected by a knock sensor. The band pass filter (2) 420 extracts only the vibration of a second frequency band B from the vibration detected by the knock sensor. The band pass filter (3) 430 extracts only the vibration of a third frequency band C from the vibration detected by the knock sensor. The band widths of the first frequency band A, the second frequency band B, and the third frequency band C are the same. The engine ECU 200 calculates the peak value of the intensity of vibration in the synthetic waveform of these frequency bands, and determines whether knocking occurs or not based on the peak value. COPYRIGHT: (C)2007,JPO&INPIT
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