| 摘要 |
PURPOSE:To improve judgment precision and perform knock control with little melfunction by judging the presence of knock occurrence with two kinds of average values widened in difference when a knock occurs. CONSTITUTION:A BPF 102 passing only a knock signal among the outputs of a knock sensor 101 is provided, a hold circuit 103 detecting and holding the peak of the knock signal is provided, and its output is inputted to an ignition control computer 105 via an A/D converter 104. The present A/D converted value VPi is compared with the previous average value LK1i-1, and the first average value LK1i is updated in the increase/decrease direction according to the compared result. VPi and K.LKli (K is a preset value) are compared, and the second average value LK2i is updated in the increase/decrease direction according to the compared result. The ignition spark advance value is determined so as to shrink the difference between the first and second average values. |
