| 摘要 |
PURPOSE:To control knocking with high detecting accuracy by inputting knocking signals to the whole A/D terminals used at a scanning function time, and using a scanning result data as a frequency analysis data. CONSTITUTION:In order to detect knocking, knocking signals 401 are passed through an analog filter 402, and a frequency component equal to or higher than 20kHz is cut, and signals containing only a frequency component lower than 20 kHz are inputted to an amplifier 403. The amplified signals are inputted simultaneously to four A/D converting input terminals of a microcomputer 404, and are converted from analog signals to digital signals. By using the microcomputer 404 by which converting times become constant at a scanning function time of an A/D converter 405, sensor signal sampling is carried out in a scanning mode of an A/D converting terminal. Thereby, knocking detecting accuracy can be increased, so that an ignition timing can be set optimum. |
