Granted Patent B2

US 7,673,621 · App. 11/853,470 · Granted Mar 9, 2010

Abstract

Claims (42)

1. A system for estimating fuel concentration, comprising:

an ethanol estimating module that generates an ethanol estimate based on baseline closed loop corrections (CLC);

a fuel system module that controls fuel to an engine and that generates a fuel system error; and

wherein said ethanol estimating module selectively adjusts said baseline CLC and said ethanol estimate based on said fuel system error.

2. The system of claim 1 further comprising:

a calculating module that generates maximum and minimum CLC values, CLC max and CLC min , respectively, based on said baseline CLC,

wherein said ethanol estimating module is enabled when said CLC max and CLC min are less than or equal to and greater than or equal to first and second predetermined values, respectively.

3. The system of claim 1 further comprising:

a refuel event determining module that identifies refueling events,

wherein said ethanol estimating module enables adjustment of said baseline CLC and said ethanol estimate when said refuel events are identified.

4. The system of claim 1 further comprising:

a baseline CLC check module that determines whether a prior baseline CLC is within predetermined criteria,

wherein said ethanol estimating module enables adjustment of said baseline CLC and said ethanol estimate when said prior baseline CLC is within said predetermined criteria.

5. The system of claim 1 wherein said ethanol estimating module enables correction when one of:

said CLC max and CLC min are greater than maximum and minimum allowed correction values, respectively; and

said CLC max and CLC min are less than said maximum and minimum allowed correction values, respectively.

6. The system of claim 5 wherein said maximum and minimum allowed correction values are calibrated values based on at least two of air meter wear, injector wear, fuel pressure regulator wear and injector plugging.

7. The system of claim 1 further comprising:

a refuel event determining module that identifies refueling events; and

a baseline CLC check module that determines whether a prior baseline CLC is within predetermined criteria,

wherein said ethanol estimating module enables adjustment of said baseline CLC and said ethanol estimate when said refuel events are identified and said prior baseline CLC is within said predetermined criteria.

8. A method for estimating fuel concentration, comprising:

generating an ethanol estimate based on baseline closed loop corrections (CLC);

controlling fuel to an engine and generating a fuel system error; and

selectively adjusting said baseline CLC and said ethanol estimate based on said fuel system error.

9. The method of claim 8 further comprising:

generating maximum and minimum CLC values (CLC max and CLC min ), respectively, based on said baseline CLC; and

enabling an ethanol estimate when said CLC max and CLC min are less than or equal to and greater than or equal to first and second predetermined values, respectively.

10. The method of claim 8 further comprising:

identifying refueling events; and

enabling adjustment of said baseline CLC and said ethanol estimate after said refuel events are identified.

11. The method of claim 8 further comprising:

determining whether a prior baseline CLC is within predetermined criteria; and

enabling adjustment of said baseline CLC and said ethanol estimate when said prior baseline CLC is within said predetermined criteria.

12. The method of claim 8 further comprising enabling correction when one of:

said CLC max and CLC min are greater than maximum and minimum allowed correction values, respectively; and

said CLC max and CLC min are less than said maximum and minimum allowed correction values, respectively.

13. The method of claim 12 wherein said maximum and minimum allowed correction values are calibrated values based on at least two of air meter wear, injector wear, fuel pressure regulator wear and injector plugging.

14. The method of claim 9 further comprising:

identifying refueling events;

determining whether a prior baseline CLC is within predetermined criteria; and

enabling adjustment of said baseline CLC and said ethanol estimate after said refuel events are identified and said prior baseline CLC is within said predetermined criteria.

Assignments (12)