| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To accurately determine fuel properties of fuel in use for an engine. <P>SOLUTION: A total heat production in a combustion zone ranging from a combustion start to a combustion termination is calculated based on cylinder inner pressure detected by a cylinder inner pressure sensor 30. A combustion period is calculated based on the total heat production, and an integration value of the combustion period in a predetermined period is compared with a predetermined determining value to thereby determining the fuel properties of fuel in use. At this time, ignition timing fixing control for fixing ignition timing or suppressing variation in ignition timing is performed from the cranking start of an engine 11 (for example, switching on of a starter) till completion of determination of fuel properties. Thereby, in condition where variation in combustion condition due to variation in ignition timing causing erroneous determination of fuel properties is almost eliminated, fuel properties are accurately determined based on the combustion period, and fuel properties determining accuracy can be improved. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
