| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent erroneous determination of knocking caused by noise superimposed on an output signal of a knocking sensor. <P>SOLUTION: In the knocking detection device, the output signal of the knocking sensor 28 is subjected to A/D conversion by an A/D conversion part 41 and acquired within a predetermined knocking determination zone, data of frequency, time, and vibration strength are concurrently extracted from the output signal of the knocking sensor 28 by a time-frequency analysis part 42, and temporal change patterns of vibration strength of a plurality of frequency regions are extracted. After calculating an edge directionθn and edge strength Vn by an edge extracting process, a correlation value CRR indicating correlation between the temporal change patterns of vibration strength of the plurality of frequency regions and a reference model indicating characteristics of knocking is calculated by a crosscorrelation/knocking determining part 43. The correlation value CRR is compared with a decision threshold, and if the correlation value CRR is larger than the decision threshold, it is determined that there is knocking, and if the correlation value CRR is the same or less than the decision threshold, it is determined that there is no knocking. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
