Intake pipe pressure prediction method and fuel injection control method for internal combustion engine

摘要

PROBLEM TO BE SOLVED: To provide a method of predicting a minimum value of the pressure inside an intake pipe of an internal combustion engine. SOLUTION: A number of crank angle positions of the internal combustion engine 1 are determined as sampling positions, and at least one sampling position among the plural sampling positions, which delays from the crank angle position when each intake process is started and advances from the crank angle position where the pressure inside the intake pipe is the minimum value in each intake process, is determined as a prediction sampling position. The value made by multiplying the difference Pn between the pressure Pn inside the intake pipe sampled at the prediction sampling position and the pressure inside the intake pipe detected at the sampling position just before the prediction sampling position and a prescribed coefficient kn is calculated as the expression that the predicted variation quantity knPn of the pressure inside the intake pipe, and the value calculated by subtracting the predicted variation quantity from the pressure Pn inside the intake pipe sampled at the prediction sampling position is to be the predicted value of the pressure inside the intake pipe.