Patent ID: 6947829
Filing Date: 2005-09-20
Classification: G01L

Abstract:
1. An apparatus for detecting occurrence of knocking of an engine from a signal sensed by a knocking sensor attached to the engine, comprising: a plurality of filters extracting, from the signal sensed by the knocking sensor, a plurality of signal components whose frequency bands differ from each other; and a knocking determination unit determining whether or not there is the occurrence of knocking on a basis of results outputted from the plurality of filters, wherein the plurality of filters include a first type of filter of which pass band is set to a first specific frequency band including a first specific frequency of the signal from knocking sensor, the first specific frequency indicating the occurrence of knocking, and a second type of filter of which pass band is set to a second specific frequency band other than the first specific frequency band, wherein both of the first and second types of filters have filtering characteristics, an inclination of the filtering characteristic of the second type of filter at a cut-off frequency thereof being steeper than an inclination of the filtering characteristic of the first type of filter at a cut-off frequency thereof.