LEARNING METHOD OF LEARNING VALUE FOR JUDGING KNOCK OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To improve learning accuracy by detecting whether a knocking signal is fluctuated or not at the time of learning of a signal level in which a knock signal is not superposed in ion current, solving fluctuation by lagging a phase of an ignition timing when fluctuation is detected, and learning the signal level in a condition in which the knock signal is nearly stabilized. SOLUTION: In the case where a learning value for judging knock is leant, in an electronic control device 6, an A/D converting value of a knock signal from ion current detected by an ion current measuring circuit 25 is set as a signal level NIONKNK. A coefficient is multiplied by a learning value memorized in a learning zone, and it is judged where the knock signal is a signal level which is not superposed or not. In the case where a learning condition is not setup, it is judged whether the knock signal is fluctuated or not. In the case where fluctuation is generated, a phase of an ignition timing is lagged, ignition phase lag control is repeated until the fluctuation of the knock signal is below a prescribed fluctuating ratio. After that, a back ground level is learnt, and a phase is advanced to an ignition timing of a normal operating condition.