US 4,974,563 A · Apparatus for estimating intake air amount

Abstract

An engine controller comprising a means for estimating an amount of the air flowing into the cylinder of the engine. The estimation means calculates the intake air amount mc(k+1) in the following equation determined from the physical model describing the law of conservation of mass for the intake air: mc(k+1)=.alpha..multidot.Q/.omega.+.beta..multidot.mc(k) where .alpha. and .beta. are constants, mc(k) is the last estimated value, Q is the flux of the detected air, and is the engine speed. The estimation is executed synchronously with the intake stroke so as to control the fuel injection amount synchronously with the intake stroke. To further improve the accuracy of the fuel injection even when the running condition of the engine changes after the estimation of the intake air amount, the fuel should be injected asynchronously with the intake stroke. We also disclose the engine controller that controls the amount of such an asynchronous injection.

Claims10

Dependent claims

An apparatus for estimating an intake air amount in an intake pipe of an engine having at least one cylinder connected to a the intake pipe for conducting air into the cylinder and a surge supressor located in the intake pipe at a first point upstream of the cylinder, said estimating apparatus comprising:

means for detecting an amount (Q) of air flowing into the intake pipe from the atmosphere, the air-flow detecting means being located at a second point in the intake pipe upstream of the first point such that the surge suppressor is disposed between the cylinder and the air-flow detecting means;
means for detecting a rotation speed (.omega.) of the engine;
means for estimating an amount {mc(k+1)} of air conducted into the cylinder, using the following equation based on a physical model that takes the surge suppressor into account and that is based on the law of conservation of mass encompassing the air-flow amount (Q), the rotation speed (.omega.) and the intake air amount {mc(k)}:
mc(k+1)=.alpha..multidot.Q/.omega.+.beta..multidot.mc(k)
where .alpha. and .beta. are constants determined by the law of conservation of mass and mc(k) is a prior estimate of the amount of air entering the engine cylinder;
and
means for controlling at least one engine operating parameter based on the estimated intake air amount.

4 more elements

An apparatus for estimating an intake air amount in an intake pipe of an engine having at least one cylinder connected to a the intake pipe for conducting air into the cylinder and a surge suppressor located in the intake pipe at a first point upstream of the cylinder, said estimating apparatus comprising:

means for detecting an amount (Q) of air flowing into the intake pipe from the atmosphere, the air-flow detecting means being located at a second point in the intake pipe upstream of the first point such that the surge suppressor is disposed between the cylinder and the air-flow detecting means;
means for detecting a rotation speed (.omega.) of the engine;
means for estimating an amount {mc(k+1)} of air conducted into the cylinder, using the following equation based on a physical model that takes the surge suppressor into account and that is based on the law of conservation of mass encompassing the air-flow amount (Q), the rotation speed (.omega.) and the intake air amount {mc(k)}:
mc(k+1)=.alpha..multidot.Q/.omega.+.beta..multidot.mc(k)
where .alpha. and .beta. are constants determined by the law of conservation of mass and mc(k) is a prior estimate of the amount of air entering the engine cylinder;
and
means for calculating a fuel amount to be injected into the cylinder of the engine from the estimated amount of air drawn into the intake pipe.

4 more elements

Dependencies are inferred from the claim text.

Apparatus for estimating intake air amount

Life of this patent

Apparatus for estimating intake air amount

Life of this patent

Abstract

Claims10