| 摘要 |
PURPOSE:To detect certainly a knocking regardless of a valve down noise, etc. of intake and exhaust valve, by setting the most suitable deciding level at every crank angle according to an engine state. CONSTITUTION:An AD conversion circuit 40 is controlled by a timing signal (e) from an AD conversion timing circuit 42, and a signal (d) obtained by passing an output of a knocking sensor 10 through a BPF 12 become a Vadj by AD conversion of each peak value thereof. At a timing circuit 52, a gate signal K for turning a gate 54 ON only between a knock deciding section and a top dead center signal (l) of each cylinder are prepared from an output signal (j) of a reference crank angle sensor 30. A weighting adder 44 performs an assembly adding by data Dij from an RAM 46 and an AD converted value Vadj of (j)th counted from a start timing of the knocking deciding section, and said value is stored in the same place of the RAM 46. The decided level Lij of an output of a deciding level arithmetic circuit 48 and the value Vadj are compared by a comparator 50 to decide the knocking. |
