| 摘要 |
PURPOSE:To enable detection with high accuracy all the time regardless of a driving state of an engine or secular change by detecting a frequency indicating the maximum level value and by using this detected frequency as a plurality of central frequencies in sampling of a frequency component of a knocking detection signal. CONSTITUTION:A knocking signals detected by a knock sensor is amplified by a front end amplifier 30 and its frequency characteristic is changed by an equalizer 31 and amplified by a variable amplifier 33. Also, processing by an AD converter 34 is executed, and at a point of time T0 when the number of AD converted data reaches, for example, 2<n>, frequency analysis is carried out by, for example, a high-speed Fourier transform 35. Also, spectral components S1 to Sk corresponding to (k) (k>1) frequencies of f1 to fk are acquired as data C, and this is made as a tone color characteristic corresponding to knocking. And weighted amounts W1 to Wk are multiplied by a processing 36 for the spectral components S1 to Sk so as to acquire a knocking signal strength I. Then, the signal strength I is compared with a standard strength I0 by a comparative processing 37, and generation of knocking is judged. |
