Internal combustion engine knock determination device and knock determination method

A knock determination method for an internal combustion engine, comprising the steps of:

• detecting vibration intensity of said internal combustion engine in an interval of predetermined crank angles;
• detecting a waveform of vibration of said internal combustion engine based on the vibration intensity of said internal combustion engine;
• calculating a first value corresponding to the vibration intensity of said internal combustion engine;
• calculating, based on a result of comparison between said detected waveform and a predetermined waveform model as a reference waveform of vibration in said internal combustion engine, a second value corresponding to a difference between said detected waveform and said waveform model;
• determining, whether or not knock has occurred in said internal combustion engine based on a result of comparison between said first value and a predetermined first determination value, and based on a result of comparison between said second value and a predetermined second determination value;
• correcting said first determination value if the number of first values not lower than said first determination value is not smaller than a first number, among the first values calculated in a plurality of predetermined number of continuous ignition cycles;
• and
• correcting said first determination value if the number of first values not lower than said first determination value is not smaller than a second number, among the first values calculated in a plurality of ignition cycles in which said second value satisfies a predetermined condition.

A knock determination device for an internal combustion engine, comprising:

• means for detecting vibration intensity of said internal combustion engine in an interval of predetermined crank angles;
• means for detecting a waveform of vibration of said internal combustion engine based on the vibration intensity of said internal combustion engine;
• means for calculating a first value corresponding to the vibration intensity of said internal combustion engine;
• means for calculating, based on a result of comparison between said detected waveform and a predetermined waveform model as a reference waveform of vibration in said internal combustion engine, a second value corresponding to a difference between said detected waveform and said waveform model;
• means for determining whether or not knock has occurred in said internal combustion engine based on a result of comparison between said first value and a predetermined first determination value, and based on a result of comparison between said second value and a predetermined second determination value;
• first correcting means for correcting said first determination value if the number of first values not lower than said first determination value is not smaller than a first number, among the first values calculated in a plurality of predetermined number of continuous ignition cycles;
• and
• second correcting means for correcting said first determination value if the number of first values not lower than said first determination value is not smaller than a second number, among the first values calculated in a plurality of ignition cycles in which said second value satisfies a predetermined condition.