PURPOSE: To make a correcting width always within a defined range even if there is the dispersion or variation with time of an engine, etc., by correctingly controlling ignition timing with the learned value of a correction quantity calculated from a crank angle position of the maximum cylinder inner pressure as the reference.
CONSTITUTION: In a control unit 11, ignition timing is controlled based on a fundamental ignition timing calculated from an engine operating condition and a correcting quantity calculated in accordance with the peak crank angle position in which a cylinder inner pressure detected by a cylinder inner pressure sensor 10 is the maximum. By learning this correcting quantity, the fundamental ignition timing is corrected with the learned value as the reference. Hence, even if there is the dispersion or variation with time, etc., of an engine 1, etc., the difference between the fundamental ignition timing and a required ignition timing can be reduced, thereby, enabling an MBT control to be performed with high responsiveness.
UCHIDA MASAAKI
KAWAMURA YOSHIHISA
