Patent ID: 7769523

Claim:
A method of estimating an air-intake amount of an internal combustion engine, comprising: detecting a value of a fluid energy amount in an interior of an air-intake passage of the engine at a first point and a value of the fluid energy amount in the interior of the air-intake passage at a second point that is apart in time from the first point in a period during which an intake valve is closed from a compression stroke to an exhaust stroke in one cycle of the internal combustion engine, by a detecting device that is disposed in the air-intake passage of the internal combustion engine to detect the fluid energy amount; and calculating a predicted air-intake amount in an intake stroke of the engine by a calculation using the values of the fluid energy amounts at the first and second points with reference to an air-intake amount calculation map showing a correlation between the values of the fluid energy amounts at the first and second points and the predicted air-intake amount in the intake stroke in which the fuel is injected, the air-intake amount calculation map being pre-created by finding the values of the fluid energy amounts in the air-intake passage at the first and second points and the air-intake amount, for plural running states of the internal combustion engine.