| 摘要 |
PURPOSE:To improve control accuracy by setting a knocking control amount corresponding to detection sensitivity decided on the basis of an output distribution width of a knocking sensor so that an accurate generating condition of knocking is decided to cope with the dispension in the detection sensitivity. CONSTITUTION:A control unit 17 decides a number of knocking pulses from a knocking detecting circuit 25 being based on a detection signal from a knocking sensor 4 corresponding to a knocking decision level. And when the knocking is generated, the generation of knocking is suppressed by delaying the ignition timing, while a knocking correction value is set so as to gradually advance the ignition timing when no knocking is generated. Further, the output amplitude value of the knocking sensor 4 is input into each cylinder as much as a predetermined number of times to obtain the means value and its distribution width. And when the distribution width is less than a predetermined value, and further the mean value is less than the mean value of respective cylinders, it is decided that the knocking detection sensitivity of that cylinder is in a deteriorated condition, and control is carried out to stop the knocking control for the cylinder. In this way, false decision in a condition of bad detection sensitivity can be prevented. |
