Method for detecting knocking in internal combustion engine

摘要

A method for detecting knocking in internal combustion engine, wherein a plurality of constants K is stored corresponding to a plurality of ranges of engine speed. A reference value is calculated from a means value of an output signal of a knock sensor, from the constant K corresponding to an engine speed and from a predetermined offset value, through a calculation of multiplying the mean value by the constant K and adding the offset value to the result of the multiplication. Then an output signal, newly provided from the knock sensor after the calculation of the mean value, is compared with the reference value so as to decide that knocking occurs in the engine when the newly given output signal of the knock sensor exceeds the reference value. Therefore, the reference value can be suitably determined corresponding to the engine speed so that a detectable lower limit of knocking intensity is kept to be substantially constant.