Patent ID: 7643932

Claim:
A knocking state determination device in an internal combustion engine, comprising: a detector for detecting a plurality of intensity values relating to an intensity of vibration caused in said internal combustion engine; a calculator for calculating a knock determination level by calculating a standard deviation value and a median of at least a part of said plurality of intensity values, and adding a product of a predetermined coefficient and said standard deviation to said median; a remover for repeatedly removing maximum values from intensity values used for calculating said knock determination level such that a deviation between a maximum value of intensity values used for calculating said knock determination level and said knock determination level becomes smaller than a predetermined deviation when the deviation between the maximum value of the intensity values used for calculating said knock determination level and said knock determination level is larger than said predetermined deviation, whereby reducing the intensity values used for calculating said knock determination level; and a determiner for determining a knocking occurrence state based on an intensity value larger than at least one value of the maximum value of the intensity values used for calculating said knock determination level and said knock determination level.