| 摘要 |
PURPOSE:To eliminate effect of such as unevenness of a knock sensor or a transient condition of an engine without the necessity of excessive adaptive manhours when knocking of the engine is detected by extracting a specific frequency of a signal detected by the knock sensor with the use of a digital filter means. CONSTITUTION:After A-D conversion of a signal from a knock sensor 8 by an A-D converter 14 at every predetermined time, several knocking frequency components are digitally processed by a digital signal processor 13, and after completion of a frequency analysis period set at every ignition cycle, the presence of knocking is determined. Then, after the determination of the knocking, data taken into a digital filter are initialized, and then a digital filter process is carried out in a frequency analysis period of the next ignition cycle. |
