Patent ID: 6360586
Filing Date: 2002-03-26
Classification: F02D,F02P,G01L,Y02T

Abstract:
A device for detecting the knocking of an internal combustion engine comprising:various sensors for detecting operation conditions of an internal combustion engine; an ionic current detecting means for detecting ionic current that flows through a spark plug during a combustion in said internal combustion engine; a filter means for picking up knock signals from said ionic current; a knocking level operation means for operating signals of a knocking level corresponding to a knocking state of said internal combustion engine based on said knock signals; an averaging means for operating an average knocking level by averaging said signals of the knocking level; an offset operation means for operating an offset value of said average knocking level depending on the operation conditions of said internal combustion engine; a background level operation means for operating a background level by adding up said average knocking level and said offset value together; and a knock judging means for judging the knocking state of said internal combustion engine by comparing said signals of the knocking level with said background level; wherein provision is further made of: a predetermined region judging means for judging said average knocking level that lies in a predetermined region; and an offset correction means for correcting said offset value depending on a result of judgement by said predetermined region judging means; wherein said predetermined region judging means judges said predetermined region when said average knocking level is in an increasing state or in a decreasing state compared to a reference region; and said offset correction means corrects said offset value toward a direction to cancel the increment or the decrement of said average knocking level depending on the result of judgement by said predetermined region judging means, and corrects said background level to an optimum value.