System and method for combustion engines

• US 20040182377A1
• Filed: 02/10/2004
• Published: 09/23/2004
• Est. Priority Date: 02/10/2003
• Status: Active Grant

• Current Assignee: Volvo Car Corporation (AB Volvo)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Johnsson, Anders H.
• Granted Patent: US 6,845,761 B2
• Time in Patent Office: Days
• US Class Current: 123/679
• CPC Class Codes: F02D 19/0636 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 19/0649 Liquid fuels having different boiling temperatures, volatilities, densities, viscosities, cetane or octane numbers
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/047 Taking into account fuel evaporation or wall wetting; special correction after fuel cut-off F02D41/126
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

The invention relates to a method for improving combustion in a combustion chamber of a combustion engine. The method comprises the first step of receiving a measured air-to-fuel ratio value. Further, the method comprises the step of receiving at least one estimated air-to-fuel ratio value. The air-to-fuel ratio estimate is generated in dependence of a predetermined fuel deposit factor. Furthermore, the method comprises the step of establishing a fuel volatility value in dependence of said measured air-to-fuel ratio value and said air-to-fuel ratio estimate. Finally the method comprises the step of controlling combustion in dependence of said fuel volatility value.

Claims

1. A method for controlling combustion in a combustion chamber of a combustion engine, comprising:

receiving (s53 ) a measured air-to-fuel ratio value,

receiving (s55 ) at least one estimated air-to-fuel ratio value, said air-to-fuel ratio estimate being generated in dependence of a predetermined fuel deposit factor,

establishing a fuel volatility value in dependence of said measured air-to-fuel ratio value and said air-to-fuel ratio estimate, and

controlling combustion in dependence of said fuel volatility value.

2. A method according to claim 1, wherein said measured air-to-fuel ratio value is compared to said air-to-fuel ratio estimate and said fuel volatility value is generated in dependence of said comparison.

3. A method according to claim 1, wherein said fuel volatility value is generated in dependence of said measured air-to-fuel ratio value and a plurality of air-to-fuel ratio estimates.

4. A method according to claim 3, wherein said plurality of air-to-fuel ratio estimates are of mutually different values.

5. A method according to claims 1, wherein said at least one air-to-fuel ratio estimate is generated in dependence of a predetermined fuel deposit factor (X_i) and at least one detected engine parameter value (M_f, M_a).

6. A method according to claim 4, wherein said plurality of mutually different air-to-fuel ratio estimates are generated in dependence of the same detected engine parameter value (M_f, M_a) and mutually different predetermined fuel deposit factor (X_i).

7. A method according to claim 1, wherein said measured air-to-fuel ratio value is delivered by an air-to fuel ratio sensor (210, 11c) positioned to detect an actual air-to-fuel ratio in an exhaust manifold (225a).

8. A system for controlling combustion in a combustion chamber of a combustion engine, comprising:

first means (335) for receiving a measured air-to-fuel ratio value (λ

_meas),

second means (P1, P2 . . . PN) for receiving at least one air-to-fuel ratio estimate (λ

₁,λ

₂ . . . λ

_N), said air-to-fuel ratio estimate being generated in dependence of a predetermined fuel deposit factor,

third means (330, 700) for generating a fuel volatility value in dependence of said measured air-to-fuel ratio value and said air-to-fuel ratio estimate, and

fourth means (360) for controlling combustion in dependence of said fuel volatility value.

9. A system according to claim 8, wherein said third means (330, 700) is adapted to compare said measured air-to-fuel ratio value to said air-to-fuel ratio estimate and to generate said fuel volatility value in dependence of said comparison.

10. A system according to claim 8, wherein said fuel volatility value is generated in dependence of said measured air-to-fuel ratio value and a plurality of air-to-fuel ratio estimates (λ

₁,λ

₂ . . . λ

_N).

11. A system according to claim 8, wherein said plurality of air-to-fuel ratio estimates (λ

₁,λ

₂ . . . λ

_N) are of mutually different values.

12. A system according to claim 8, wherein said third means (330, 700) is adapted to generate at least one air-to-fuel ratio estimate (λ

₁,λ

₂ . . . λ

_N)in dependence of a predetermined fuel deposit factor (X_i) and at least one detected engine parameter value (M_f, M_a).

13. A system according to claim 8, wherein said third means (330, 700) is adapted to generate a plurality of mutually different air-to-fuel ratio estimates (λ

₁,λ

₂ . . . λ

_N) in dependence of the same detected engine parameter value (M_f, M_a) and mutually different predetermined fuel deposit factor (X_i).

14. A system according to claim 8, wherein said air-to-fuel ratio sensor (210, 11) is positioned to detect an actual air-to-fuel ratio value in an exhaust pipe (228) and adapted to deliver said measured air-to-fuel ratio value (λ

_meas)

15. A computer program for causing a computerized apparatus (8;

700) to improve combustion in a combustion chamber of a combustion engine, comprising;

a computer readable code means which, when run on a computerized apparatus (8, 700), causes the computerized apparatus (8;

700) to;

receive (s53 ) a measured air-to-fuel ratio value, receive (s55 ) at least one estimated air-to-fuel ratio value, said air-to-fuel ratio estimate being generated in dependence of a predetermined fuel deposit factor,

establish a fuel volatility value in dependence of said measured air-to-fuel ratio value and said air-to-fuel ratio estimate, and

control combustion in dependence of said fuel volatility value.