| 摘要 |
PURPOSE:To simplify the structure by obtaining the vibration level of each specified block and its average value on the basis of a knock signal, forming the knock discriminating threshold on the basis of the obtained average value, and performing knock discrimination according to the compared result between the vibration level and the threshold. CONSTITUTION:The output signal A of a knock sensor 1 fitted at an internal combustion engine is inputted into an interface circuit 20 formed of a peak circuit 26, and a peak level VP as the vibration level of each specified block to a cylinder reference position is formed on the basis of the signal A. This peak level VP is inputted into an ECU 40 to be subjected to averaging process so as to form a first average value VA1, as well as this value VA1, is subjected to averaging process every specified period so as to form a second average value VA2. The threshold VTH is formed by an arithmetic part 43 on the basis of the second average value VA2, compared (44) to the peak level VP, and a knock discrimination signal VK is outputted in the case of VP>VTH to form a lag angle control angle thetaR from a lag angle reflecting-processing part 45. |
