FUEL COMPOSITION RECOGNITION AND ADAPTATION SYSTEM

• US 20090306875A1
• Filed: 04/02/2009
• Published: 12/10/2009
• Est. Priority Date: 06/05/2008
• Status: Active Grant

• Current Assignee: Robert Bosch LLC (Robert Bosch GmbH)
• Original Assignee: Robert Bosch LLC (Robert Bosch GmbH)
• Inventors: Jiang, Li, Oliverio, Nestor H., Stefanopoulou, Anna G., Yilmaz, Hakan
• Granted Patent: US 8,185,293 B2
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: F02D 19/0623 Failure diagnosis or prevention; Safety measures; Testing
• CPC Class Codes: F02D 19/0642 at least one fuel being gaseous, the other fuels being gaseous or liquid at standard conditions
• CPC Class Codes: F02D 19/0689 for in-cylinder direct injection
• CPC Class Codes: F02D 19/084 Blends of gasoline and alcohols, e.g. E85
• CPC Class Codes: F02D 19/088 by estimation, i.e. without using direct measurements of a corresponding sensor
• CPC Class Codes: F02D 2200/0612 determined by estimation
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• 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 41/06 for engine starting or warming up F02D41/0255 takes precedence
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/2441 characterised by the learning conditions
• CPC Class Codes: F02D 41/2451 characterised by what is learned or calibrated
• CPC Class Codes: F02D 41/3029 further comprising a homogeneous charge spark-ignited mode
• CPC Class Codes: F02D 41/402 Multiple injections
• CPC Class Codes: Y02T 10/30 Use of alternative fuels, e.g. biofuels

Abstract

A method of operating an internal combustion engine. The method including monitoring a pressure in a combustion chamber of the engine during a compression stroke, determining whether a fuel composition has changed from a first composition to a second composition based at least in part on the monitored pressure, and triggering a fuel composition adaptation in response to a determination that the fuel composition has changed.

Claims

1. A method of operating an internal combustion engine, the method comprising:

monitoring a pressure in a combustion chamber of the engine during a compression stroke;

determining whether a fuel composition has changed from a first composition to a second composition based at least in part on the monitored pressure; and

triggering a fuel composition adaptation in response to a determination that the fuel composition has changed.

2. The method of claim 1, further comprising:

after triggering the fuel composition adaptation, determining that the fuel composition has reached a steady-state condition; and

deactivating the fuel composition adaptation in response to the steady-state condition.

3. The method of claim 2, wherein determining that the fuel composition has reached a steady-state condition is based at least in part on the monitored pressure.

4. The method of claim 1, further comprising deactivating a fuel system adaptation in response to a determination that the fuel composition has changed.

5. The method of claim 4, further comprising:

after triggering the fuel composition adaptation, determining that the fuel composition has reached a steady-state condition; and

reactivating the fuel system adaptation in response to the steady-state condition.

6. The method of claim 5, wherein the fuel system adaptation is operable to detect fuel system faults and airflow system faults not directly associated with fuel composition.

7. The method of claim 1, further comprising running a fuel system adaptation while monitoring a pressure in a combustion chamber of the engine during a compression stroke and while determining whether a fuel composition has changed from a first composition to a second composition.

8. The method of claim 1, wherein monitoring the pressure in the combustion chamber of the engine includes determining a characteristic feature of the fuel that is a function of the pressure in the combustion chamber of the engine during the compression stroke.

9. The method of claim 8, wherein the characteristic feature includes at least one of an effective polytropic compression coefficient of the fuel, an evaporation enthalpy of the fuel, an effective charge cooling factor of the fuel, and the monitored pressure.

10. The method of claim 8, wherein determining whether the fuel composition has changed includes monitoring the characteristic feature intermittently over time.

11. The method of claim 8, wherein determining whether the fuel composition has changed includes monitoring the characteristic feature continuously over time.

12. The method of claim 8, wherein the fuel composition adaptation includes determining a fuel composition of the fuel based at least in part on the characteristic feature.

13. The method of claim 12, wherein determining the fuel composition includes a comparison of the characteristic feature with a lookup table.

14. The method of claim 1, wherein determining whether a fuel composition has changed includes utilizing an updating physical model.

15. The method of claim 1, wherein the fuel composition adaptation includes determining a fuel composition of the fuel based on the pressure monitored in the combustion chamber during the compression stroke.

16. The method of claim 1, wherein the fuel composition adaptation includes adjusting engine operation settings.

17. The method of claim 1, wherein the fuel composition adaptation includes utilizing at least one of data from an exhaust gas sensor and data from a pressure monitored in the combustion chamber during a combustion stroke.

18. The method of claim 1, wherein determining whether a fuel composition has changed is based at least in part on a fuel tank refilling event.

19. A method of operating an internal combustion engine, the method comprising:

monitoring a pressure in a combustion chamber of the engine during a compression stroke;

determining whether a fuel composition has changed from a first composition to a second composition based at least in part on the monitored pressure;

in response to a determination that the fuel composition has changed, activating a fuel composition adaptation;

after activating the fuel composition adaptation, determining that the fuel composition has reached a steady-state condition;

in response to a determination that the fuel composition has reached the steady-state condition, deactivating the fuel composition adaptation; and

after deactivating the fuel composition adaptation, determining whether the fuel composition has changed from the second fuel composition to a third fuel composition based at least in part on the monitored pressure;

wherein monitoring the pressure in the combustion chamber of the engine includes determining a characteristic feature of the fuel that is a function of the pressure in the combustion chamber of the engine during the compression stroke.

20. The method of claim 19, wherein monitoring the pressure in the combustion chamber of the engine includes intermittently monitoring the characteristic feature during operation of the internal combustion engine.