Patent ID: 7478624

Claim:
An ignition timing control device of an internal combustion engine, comprising: a first detector that detects intensity values in a plurality of ignition cycles, said intensity values relating to an intensity of vibration caused in said internal combustion engine in a predetermined first crank angle interval; a second detector that detects waveforms of vibration in said plurality of ignition cycles, said waveforms of vibration being caused in said internal combustion engine in a predetermined second crank angle interval; a storage portion that stores a model waveform of vibration of said internal combustion engine; a calculator portion that calculates a value relating to a deviation between said detected waveform and said stored model waveform based on a result of comparing said detected waveform with said stored model waveform; and a controller that controls ignition timing of said internal combustion engine based on an intensity value that is selected from said plurality of intensity values, that satisfies a predetermined first condition, and that is detected in an ignition cycle in which the value relating to the deviation between said detected waveform and said stored model waveform satisfies a predetermined second condition.