| 摘要 |
PROBLEM TO BE SOLVED: To further improve the accuracy of knocking determination referring to an ion current.SOLUTION: An ion current signal measured via a circuit for detecting an ion current is divided into two parts at reference timing. The ratio of the integrated quantity A of the ion current signal from a point of time after ignition to the reference timing to the integrated quantity B of the ion current signal from the reference timing to the end of an expansion stroke is obtained. The presence/no presence of knocking is determined based on a value obtained by multiplying the ratio by the ion current signal. The ratio is increased when the possibility of the generation of knocking is high while the ratio is decreased when the possibility is low. By multiplying the ratio by the ion current signal, the signal attributable to the knocking can be emphasized irrespective of the superposition of any noise or false knock signal on the ion current signal. |
