| 摘要 |
PURPOSE:To detect the knocking accurately by extracting a specified frequency component from an electric signal corresponding to the vibration of an internal combustion engine, judging the knocking by the ratio of two consecutive sampled values at every specified time interval, thereby facilitating the determination of a threshold value. CONSTITUTION:The vibration of the internal combustion engine is converted into the electric signal by an electric signal converter part 1. The specified frequency component, whose variation becomes large at the knocking part within said electric signal, is extracted in a specified frequency extracting part 2. Sampling is performed in a sampling part 3 at every specified time interval. The ratio computation of the two consecutive sampled values from the sampling part 3 is performed in a ratio value computing part 4. The knocking is judged by a knocking detecting part 5 based on whether this ratio exceeds the thrshold value or not. In this constitution, the threshold value in the detecting part 5 is determined readily and positively regardless of the effect such as the signal level variation due to the causes other than the knocking. Therefore the accurate knocking detection can be performed. |
