Patent ID: 8909459
Filing Date: 2014-12-09
Classification: F02D,G01L

Abstract:
1. A knock control apparatus for an internal combustion engine, comprising: a sensor that outputs a signal corresponding to a combustion state of the internal combustion engine; a knock signal calculation portion that calculates, as a knock signal, a characteristic component of a knock using the output from the sensor at every spark timing; a knock signal normalization portion that normalizes the knock signal using a base statistic calculated on the basis of the knock signal; a knock determination threshold calculation portion that sets a knock determination threshold on the basis of the normalized knock signal; a knock determination portion that determines an occurrence of a knock in a case where the normalized knock signal exceeds the knock determination threshold set by the knock determination threshold calculation portion; and an operating state determination portion that determines an operating state of the internal combustion engine, wherein the knock signal normalization portion calculates, the knock signal normalization portion normalizes the knock signal using the calculated base statistic 3; and the base statistic 3 is calculated in reference to the base statistic 2 in a state in which the operating state determination portion determines that the internal combustion engine is not in an operating state such that accompanies a variance of the knock signal, and in a state in which the operating state determination portion determines that the internal combustion engine is in an operating state such that accompanies a variance of the knock signal, influences of the base statistic 1 are calculated more significantly into the base statistic 3 as a measure of the variance of the knock signal increases.