Patent ID: 7533559

Claim:
An engine knocking detection apparatus coupled to receive a sensor signal from a knocking sensor that detects vibration of an internal combustion engine, the apparatus comprising: bandpass filter means for filtering said sensor signal to select a knocking frequency component that has a local maximum vibration amplitude whose frequency varies with crank angle and is within a frequency range that is specific to occurrence of knocking in said internal combustion engine, and knocking judgment means coupled to receive a filtered signal produced from said bandpass filter means, for judging whether or not engine knocking is occurring, based on said filtered signal; wherein said engine knocking detection apparatus comprises filter control means for successively adjusting a passband of said bandpass filter means during one combustion stroke interval of said interval combustion engine to track frequency changes that occur in said knocking frequency component as a function of only the absolute crank angle during said one combustion stroke interval of said internal combustion engine.