| 摘要 |
<P>PROBLEM TO BE SOLVED: To further improve accuracy of determining a combustion state by reference to an ion current. <P>SOLUTION: When determining a combustion state in a cylinder of the internal combustion engine by using a circuit which detects an ion current I flowing in electrodes of an ignition plug 13 by applying a bias voltage V due to charge Q stored in a capacitor 141 to the electrode, the ion current I is measured repetitively and a charge amount Q' flowing out from the capacitor 141 or a capacitor voltage V is calculated from the time series of the measured values. A resistance value R between the electrodes of the ignition plug 13 is determined on the basis of the charge amount Q' or the capacitor voltage V. The combustion resistance R indicates the combustion state in the cylinder. <P>COPYRIGHT: (C)2013,JPO&INPIT |
