Patent ID: 7455047
Filing Date: 2008-11-25
Classification: F02D

Abstract:
1. A control unit for controlling an internal-combustion engine, the apparatus comprising: pressure detecting means, provided in a combustion chamber of the engine, for detecting pressure; estimating means for estimating a motoring pressure of the engine; means for detecting a combustion starting time when a difference between an internal pressure determined based on an output of the pressure detecting means and the pressure estimated by the estimation means exceeds a predetermined value, wherein, when the pressure detected based on the output of the pressure detecting means reaches a maximum after the combustion starting time has been detected, the crank angle at this time point is determined to correspond to the maximum internal pressure that is generated by combustion; means for calculating a capacity of the combustion chamber of the engine; means for determining intake air volume; and means for determining a temperature of the intake air, wherein the estimating means estimates a motoring pressure based on a state equation using the capacity of the combustion chamber, the intake air volume and the temperature of the intake air.