Calculation of air charge amount in internal combustion engine

• US 7,151,994 B2
• Filed: 01/13/2004
• Issued: 12/19/2006
• Est. Priority Date: 02/05/2003
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Fuwa, Naohide
• Primary Examiner(s): KWON, JOHN
• Application Number:
  US10/544,125
• Publication Number:
  US 20060037596A1
• Time in Patent Office: 1,071 Days
• Field of Search: 701/103, 701/104, 701/114, 701/115, 123681-684, 123/690, 123/478, 123/480, 123/90.11, 123/90.15, 731/182
• US Class Current: 701/114
• CPC Class Codes: F02D 2200/0402 the parameter being determined by using a model of the engine intake or its components
• CPC Class Codes: F02D 2200/0406 Intake manifold pressure
• CPC Class Codes: F02D 2200/0408 Estimation of intake manifold pressure
• CPC Class Codes: F02D 41/18 by measuring intake air flow
• CPC Class Codes: F02D 41/2451 characterised by what is learned or calibrated
• CPC Class Codes: F02D 41/32 of the low pressure type F02D41/3082 takes precedence

Abstract

Calculation models (22, 24) for an in-cylinder air charge amount determine an estimated intake air pressure (Pe) based on an intake air flow rate (Ms), and then determine an air charge amount (Mc) from the estimated intake air pressure (Pe). A correction execution module (26) corrects, while a vehicle is traveling, the calculation model based on the relationship between the estimated intake air pressure (Pe) and a measured intake air pressure (Ps).

Claims

1. A control device for an internal combustion engine installed in a vehicle, comprising:

a flow rate sensor for measuring fresh air flow rate in an intake air passage connected to a combustion chamber of the internal combustion engine;

a pressure sensor for measuring pressure within the intake air passage;

an air charge amount calculation module, comprised of an intake piping model, an intake valve model and a correction execution module for calculating air charge amount to the combustion chamber according to a calculation model that includes as parameters measurement by the flow rate sensor and pressure within the intake air passage; and

the correction execution module for correcting the calculation model based on measurement by the flow rate sensor and measurement by the pressure sensor,

wherein the calculation model is a model wherein the intake piping model estimates pressure within the intake air passage based on an output signal of the flow rate sensor, and the intake valve model utilizes the estimated pressure to calculate air charge amount to the combustion chamber, and

the correction execution module executes correction of the intake valve model by a difference between the estimated pressure and pressure measured by the pressure sensor.

2. A control device according to claim 1, wherein

the internal combustion engine comprises a variable valve mechanism enabling modification of flow passage resistance at a location of an intake valve by means of changing a working angle of the intake valve, and

relationships of pressure within the intake air passage to the air charge amount in the computation model are established with reference to operating conditions specified in terms of a plurality of operating parameters that include the working angle of the intake valve.

3. A control device according to claim 2, wherein

the correction execution module, by means of executing correction of the calculation model, compensates for error concerning relationship between size of the working angle of the intake valve and flow passage resistance at the intake valve location.

4. A control device according to claim 1, further comprising:

a fuel feed controller for controlling a feed amount of fuel flowing into the combustion chamber; and

an air-fuel ratio sensor disposed on an exhaust passage connected to the combustion chamber,

wherein the correction execution module is able to correct the flow rate sensor according to a measured air-fuel ratio so that the measured air-fuel ratio measured by the air-fuel ratio sensor, the fuel feed amount established by the fuel feed controller, and the air charge amount determined based on the output signal of the flow rate sensor are consistent with one another, and correction of the calculation model is executed after correction of the flow rate sensor.

5. A control device according to claim 1, wherein

the correction execution module executes the correction during a period in which revolution and load of the internal combustion engine are substantially constant.

6. A method for calculating air charge amount in an internal combustion engine installed in a vehicle, comprising:

(a) providing a flow rate sensor for measuring fresh air flow rate in an intake air passage connected to a combustion chamber of the internal combustion engine, and a pressure sensor for measuring pressure within the intake air passage;

(b) calculating air charge amount to the combustion chamber according to a calculation model that includes as parameters measurement by the flow rate sensor and pressure within the intake air passage; and

(c) correcting the calculation model based on measurement by the flow rate sensor and measurement by the pressure sensor,

wherein the calculation model is a model that estimates pressure within the intake air passage based on an output signal of the flow rate sensor as input into an intake piping model, and utilizes the estimated pressure as input into an intake valve model to calculate air charge amount to the combustion chamber, and

the step (c) includes a step of executing correction of the intake valve model by a difference between the estimated pressure and pressure measured by the pressure sensor coincide.

7. A method according to claim 6 wherein

the internal combustion engine comprises a variable valve mechanism enabling modification of flow passage resistance at a location of an intake valve by means of changing a working angle of the intake valve, and

relationships of pressure within the intake air passage to the air charge amount in the computation model are established with reference to operating conditions specified in terms of a plurality of operating parameters that include the working angle of the intake valve.

8. A method according to claim 7 wherein

the step (c) includes compensating for error concerning relationship between size of the working angle of the intake valve and flow passage resistance at the intake valve location, by means of executing correction of the calculation model.

9. A method according to claim 6 wherein

the internal combustion engine further comprises:

a fuel feed controller for controlling a feed amount of fuel flowing into the combustion chamber; and

an air-fuel ratio sensor disposed on an exhaust passage connected to the combustion chamber,

wherein the step (c) includes the steps of;

correcting the flow rate sensor according to a measured air-fuel ratio so that the measured air-fuel ratio measured by the air-fuel ratio sensor, the fuel feed amount established by the fuel feed controller, and the air charge amount determined based on the output signal of the flow rate sensor are consistent with one another; and

executing correction of the calculation model after correction of the flow rate sensor.

10. A method according to claim 6 wherein

the correction in the step (c) is executed during a period in which revolution and load of the internal combustion engine are substantially constant.

11. A control device for an internal combustion engine installed in a vehicle, comprising:

a first sensor for measuring a parameter which is usable to estimate pressure within an intake air passage;

a second sensor for measuring pressure within the intake air passage; and

a correction execution module for correcting air charge amount to the combustion chamber, calculated by an intake valve model, based on pressure estimated by an intake piping model from the parameter measured by the first sensor and pressure measured by the second sensor.

12. A control device for an internal combustion engine installed in a vehicle, comprising:

a first sensor for measuring a parameter which is usable to estimate pressure within an intake air passage;

a second sensor for measuring pressure within the intake air passage; and

a correction execution module for correcting air charge amount to the combustion chamber, calculated by an intake valve model, based on the parameter measured by the first sensor and pressure measured by the second sensor,

wherein the correction execution module executes the correction of the air charge amount to the combustion chamber after executing correction of the first sensor.