| 摘要 |
PURPOSE:To detect the knocking coping with the kind of engine and the secular change by A/D-converting the signal of a knock sensor, storing the signal as the data train in time sequence, obtaining a plurality of frequency components through the addition and subtraction calculation of the data train, detecting the relation of magnitude from a threshold value for each component and combining the relation of magnitude of each component. CONSTITUTION:A cylinder internal pressure sensor or knock sensor detects the pressure variation accompanied with the combustion in a combustion chamber or the vibration in the generation of knocking, and the signal having a sufficient amplitude through amplification can be A/D-converted. A means for region restriction can eliminate the influence of the repetitive frequency in the frequency analysis. A/D conversion is carried out at each certain time interval, and the data train is stored, and the input signal can be analyzed in time sequence. Knocking can be detected by analyzing the frequency only for a specific frequency by analyzing the data train. The method for frequency analysis can be carried out at high speed by using only addition and subtraction calculation. |
