Estimation device for cylinder intake air amount in an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9228519-B2
Application number	US-201313850747-A
Country	US
Kind code	B2
Filing date	Mar 26, 2013
Priority date	Oct 25, 2012
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

An estimation device for a cylinder intake air amount in an internal combustion engine can estimate a cylinder intake air amount to a sufficient accuracy for suitable engine control, in either of steady state operation and transient operation with a small number of adaptation constants and a small amount of calculation load, without requiring a huge memory capacity. The relation between an opening degree and an effective opening area of a throttle valve has been learned, while calculating the cylinder intake air amount in an S/D method from a volumetric efficiency correction factor map adapted by valve timing at the time of steady state operation, and in a period from a transient change until an exhaust manifold temperature is converged, an intake air amount is calculated based on the relation thus learned. The cylinder intake air amount is calculated based on a physical model of an intake system response delay.

First claim

What is claimed is:

1. An estimation device for a cylinder intake air amount in an internal combustion engine, which serves for estimating a cylinder intake air amount sucked into a cylinder in the internal combustion engine which is connected to an intake pipe at a location downstream of a throttle valve, said estimation device comprising:
a variety of kinds of sensors that detect operating states of said internal combustion engine related to a variety of kinds of actuators; and
a physical model that models a response delay of an intake system until the air having passed through said throttle valve comes into said cylinder, by using detected values of said variety of kinds of sensors as input information;
wherein said variety of kinds of actuators include a throttle opening degree control unit that regulates an amount of air passing through said throttle valve by controlling a throttle opening degree of said throttle valve thereby to change an effective opening area thereof;
wherein said variety of kinds of sensors include:
an atmospheric air temperature sensor that detects an atmospheric air temperature at an atmospheric air side of said throttle valve;
an atmospheric air pressure sensor that detects an atmospheric air pressure at the atmospheric air side of said throttle valve; and
an intake manifold pressure sensor which detects a pressure in the intake pipe at a downstream side of said throttle valve as an intake manifold pressure;
wherein said physical model includes:
a volumetric efficiency corresponding value calculation unit that calculates a volumetric efficiency corresponding value which is an index indicating said cylinder intake air amount;
a throttle opening degree learning unit that calculates a learning corrected target throttle opening degree for achieving a target amount of intake air by learning a relation between said throttle opening degree and said effective opening area; and
a cylinder intake air amount calculation unit that calculates said actual cylinder intake air amount;
wherein at the time of steady state operation, the estimation of said actual cylinder intake air amount by said cylinder intake air amount calculation unit is carried out by using said intake manifold pressure and said volumetric efficiency corresponding value, and at the same time, opening degree learning by said throttle opening degree learning unit is carried out based on said actual cylinder intake air amount, whereas at the time of steady state operation, after the opening degree learning by said throttle opening degree learning unit is stopped, an amount of intake air having passed through the throttle valve is estimated by applying the actual effective opening area calculated from said throttle opening degree and a result of said opening degree learning, said intake manifold pressure, said atmospheric air pressure and said atmospheric air temperature to a flow rate calculation expression of a throttle type flow meter, and at the same time, the calculation of said actual cylinder intake air amount by said cylinder intake air amount calculation unit is carried out based on said amount of intake air.

2. The estimation device for a cylinder intake air amount in an internal combustion engine, as set forth in claim 1 ,
wherein said throttle opening degree learning unit is provided with:
a target intake air amount calculation unit that calculates said target amount of intake air based on an operating state of said internal combustion engine;
a target effective opening area calculation unit that calculates a target effective opening area which is regulated by said throttle opening degree control unit, by applying said target amount of intake air, said intake manifold pressure, said atmospheric air pressure and said atmospheric air temperature to the flow rate calculation expression of the throttle type flow meter;
a learning effective opening area calculation unit that calculates a learning effective opening area of said throttle opening degree control unit, by applying said actual cylinder intake air amount for carrying out control of said internal combustion engine, said intake manifold pressure, said atmospheric air pressure and said atmospheric air temperature to the flow rate calculation expression of said throttle type flow meter; and
a throttle opening degree learning value calculation unit that calculates a throttle opening degree learning value for calculating said learning corrected target throttle opening degree, by learning the relation between said throttle opening degree and said effective opening area in such a manner that said learning effective opening area is made to coincide with said target effective opening area.

3. The estimation device for a cylinder intake air amount in an internal combustion engine, as set forth in claim 2 ,
wherein said throttle opening degree learning value calculation unit is provided with:
a throttle opening degree learning basic value calculation unit that calculates a throttle opening degree learning basic value for making said learning effective opening area and said target effective opening area coincident with each other;
a real-time learning value calculation unit that calculates a real-time learning value from said throttle opening degree learning basic value;
a long time learning value calculation unit that calculates a long time learning value from said throttle opening degree learning basic value;
a long time learning value storage unit that stores said long time learning value; and
an adder that calculates said throttle opening degree learning value by adding said long time learning value, which has been stored in said long time learning value storage unit, and said real-time learning value θR to each other.

4. The estimation device for a cylinder intake air amount in an internal combustion engine, as set forth in claim 3 ,
wherein said throttle opening degree learning value calculation unit is provided with a long time learning value monotonically increasing processing unit for ensuring a monotonically increasing state of said long time learning value.

5. The estimation device for a cylinder intake air amount in an internal combustion engine, as set forth in claim 1 ,
wherein said physical model includes:
a first physical model that estimates said cylinder intake air amount based on the amount of intake air having passed through said throttle valve; and
a second physical model that is composed of an inverse model that is an inverse of said first physical model, and estimates the amount of intake air having passed through said throttle valve based on said cylinder intake air amount;
wherein at the time of said steady state operation, said physical model estimates a first amount of intake air having passed through said throttle valve by using said actual cylinder intake air amount and said second physical model, carries out said opening degree learning based on said first amount of intake air, and at the same time, estimates again said actual cylinder intake air amount by using said first amount of intake air and said first physical model; and
wherein at the time of said transient operation, said physical model estimates a second amount of intake air having passed through said throttle valve, by applying said actual effective opening area, said intake manifold pressure, said atmospheric air pressure and said atmospheric air temperature to said flow rate calculation expression, and at the same time, estimates said actual cylinder intake air amount by using the second amount of intake air and said first physical model.

6. The estimation device for a cylinder intake air amount in an internal combustion engine, as set forth in claim 5 ,
wherein said first physical model includes an intake manifold density calculation unit tha

Assignees

• Hagari Hideki
• Mitsubishi Electric Corp

Inventors

• Hagari Hideki

Classifications

• F02D41/2451

  characterised by what is learned or calibrated · CPC title

• F02D2200/0404

  Throttle position · CPC title

• F02D2200/0414

  Air temperature · CPC title

• F02D41/182 Primary

  for the control of a fuel injection device · CPC title

• F02D11/106

  Detection of demand or actuation · CPC title