Patent ID: 7669582

Claim:
A knocking state determination device in an internal combustion engine, comprising: a first detecting portion for detecting a waveform of vibration caused in said internal combustion engine at a predetermined interval for a crank angle; a memory portion for previously storing a waveform of vibration of said internal combustion engine; a second detecting portion for detecting magnitude values relating to magnitude of vibration caused in said internal combustion engine in a plurality of ignition cycles; an extracting portion for extracting a magnitude value satisfying a predetermined condition among said plurality of magnitude values based on a result of comparing said detected waveform with said stored waveform; a determining portion for determining a knocking occurrence state based on said magnitude value extracted; a knock magnitude calculating portion for calculating a knock magnitude relating to a magnitude of vibration caused by knocking, based on the result of comparing said stored waveform and the detected waveform and a magnitude of vibration caused in said internal combustion engine at said predetermined interval for the crank angle; a knocking determining portion for determining whether knocking has occurred in said internal combustion engine for each ignition cycle based on a result of comparing said knock magnitude and a predetermined determination value; and a correcting portion for correcting said predetermined determination value based on a determination result by said determining portion.