Patent ID: 7677083

Claim:
A knocking determination device for an internal combustion engine, comprising: a crank angle detecting unit that detects a crank angle of said internal combustion engine; a waveform detecting unit that detects a vibration waveform of said internal combustion engine between predetermined crank angles; a storage unit that stores in advance a predetermined attenuation factor of a vibration waveform that corresponds to knocking, wherein the predetermined attenuation factor is a single value that corresponds to attenuation over time of the vibration waveform that corresponds to knocking, beginning after an angle that corresponds to a peak value of the vibration waveform that corresponds to knocking; and a determining unit that determines whether knocking occurred in said internal combustion engine or not based on a result of comparison between said detected vibration waveform and a waveform derived from said stored attenuation factor, wherein said determining unit normalizes said detected vibration waveform based on a value that corresponds to a peak of a magnitude of vibration of said detected vibration waveform, calculates a deviation in the magnitude of vibration of said detected vibration waveform by matching a peak timing of said normalized detected vibration waveform with a peak timing of said waveform derived from said stored attenuation factor, calculates a coefficient of correlation that relates to said deviation between said normalized detected vibration waveform and said waveform derived from said stored attenuation factor based on said calculated deviation, and determines whether knocking occurred in said internal combustion engine or not based on said calculated coefficient of correlation.