Knocking determination device and knocking control device

A knocking determination device comprising:

• a detection unit configured to detect a vibration generated in an internal combustion engine during a predetermined period in each combustion cycle of the internal combustion engine;
• a knocking determination unit configured to perform a knocking determination of a presence or absence of a knock based on a vibration waveform in a predetermined frequency band component of the vibration detected, the predetermined frequency band component being a vibration equal to or more than a predetermined lower limit frequency and equal to or less than a predetermined upper limit frequency;
• an end determination unit configured to determine an end of an individual waveform that is a waveform of each predetermined series of vibrations included in the vibration waveform, and recognize a boundary between the individual waveforms;
• and
• a feature extraction unit configured to perform an extraction work that extracts a feature of the individual waveform based on recognizing the boundary, wherein
• the end determination unit determines that one of the individual waveforms ends on condition that a vibration intensity in the waveform exceeds a predetermined first threshold value, falls below the first threshold value, and then the vibration intensity falling below the first threshold value continues for equal to or greater than a predetermined end determination time, the predetermined end determination time is a time having a length equal to or more than a reciprocal of the lower limit frequency and twice or less the reciprocal of the lower limit frequency, and
• the knocking determination unit determines whether the feature of the individual waveform matches with a feature of a knocking waveform, and determines that the knock exists on condition determining that the feature of the individual waveform matches with the feature of the knocking waveform.