COMBUSTION NOISE SUPPRESSION CONTROL APPARATUS FOR INTERNAL COMBUSTION ENGINE

Data on an in-cylinder pressure (CP) resulting from pilot injection are extracted based on in-cylinder pressure data (Dcp) (S12), and are subjected to Fourier transform to be thereby converted into data indicating a relationship between a frequency and a sound pressure level (S14). Subsequently, the converted data are subjected to bandpass filter processes for a plurality of frequencies respectively (S16). When the sound level at each of the frequencies exceeds a threshold (Th1, Th2, Th3...) provided for each of the frequencies, an amount of excess over the threshold is calculated (S18). Then, a combustion noise correction amount (”Qpcs) is calculated based on the amount of excess (S22).