| 摘要 |
A spark ignition internal combustion engine includes: a compression ratio changing mechanism by which a volume of a combustion chamber varies; a cylinder internal pressure sensor that acquires a pressure signal of a pressure vibration inside a cylinder; and an abnormal combustion detector including a filter that passes the pressure signal, of a set frequency band among the pressure signal, and detecting an occurrence of abnormal combustion based on the pressure signal having passed through the filter. The abnormal combustion detector sets a frequency band of the filter based on a crank angle section in which abnormal combustion occurs and on a mechanical compression ratio. |
