Methods and systems for adjusting fuel injector operation

• US 9,404,435 B2
• Filed: 12/01/2014
• Issued: 08/02/2016
• Est. Priority Date: 12/01/2014
• Status: Active Grant

• Current Assignee: Zebra Technologies Corporation
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Ranga, Adithya Pravarun Re, Surnilla, Gopichandra, Sanborn, Ethan D., Thomas, Joseph Lyle, Meinhart, Mark
• Primary Examiner(s): Vo, Hieu T
• Application Number:
  US14/556,752
• Publication Number:
  US 20160153386A1
• Time in Patent Office: 610 Days
• US Class Current: 1/1
• CPC Class Codes: F02D 41/1454 the characteristics being an oxygen content or concentration or the air-fuel ratio
• CPC Class Codes: F02D 41/2467 for injectors
• CPC Class Codes: F02D 41/3094 the fuel injection being effected by at least two different injectors, e.g. one in the intake manifold and one in the cylinder

Abstract

Systems and methods for improving fuel injection of an engine that includes a cylinder receiving fuel from two different fuel injectors is disclosed. In one example, a transfer function or gain of a direct fuel injector is adjusted in response to an exhaust lambda value and a fraction of fuel supplied to a cylinder during a cylinder cycle.

Claims

1. A system, comprising:

an engine including a cylinder;

a port fuel injector in fluidic communication with the cylinder;

a direct fuel injector in fluidic communication with the cylinder; and

a controller including executable instructions stored in non-transitory memory for commanding the engine to operate at a constant air-fuel ratio while supplying fuel to the cylinder via the port fuel injector and the direct fuel injector, additional instructions for increasing a fuel pressure supplied to the direct fuel injector while continuing to command the engine to operate at the constant air-fuel ratio, and additional instructions to operate the direct fuel injector in a ballistic mode via decreasing a fuel pulse width supplied to the direct fuel injector while continuing to command the engine to operate at the constant air-fuel ratio.

2. The system of claim 1, further comprising additional instructions to operate the engine at a constant speed and air mass while commanding the engine to operate at the constant air-fuel ratio.

3. The system of claim 1, further comprising additional instructions to adjust a transfer function or gain of the direct fuel injector.

4. The system of claim 3, where the transfer function or gain is adjusted based on an exhaust lambda.

5. The system of claim 4, where the transfer function or gain is adjusted further based on a fuel fraction provided to the cylinder via the direct fuel injector during a cylinder cycle.

6. The system of claim 1, further comprising additional instructions to incrementally increase fuel pressure supplied to the direct fuel injector while the engine is commanded to operate at the constant air-fuel ratio.

7. A method for fueling a cylinder, comprising:

operating a fuel injector in a ballistic operating region supplying fuel to the cylinder; and

adjusting a control parameter of the fuel injector in response to exhaust lambda and a fuel fraction provided to the cylinder by the fuel injector; and

operating the fuel injector based on the adjusted control parameter.

8. The method of claim 7, where the ballistic operating region is an operating region where fuel flow through the fuel injector is non-linear.

9. The method of claim 7, where the control parameter is a fuel injector gain or transfer function.

10. The method of claim 7, where the adjusted control parameter is stored to memory.

11. The method of claim 7, where the fuel injector is a direct fuel injector.

12. The method of claim 7, where the cylinder is in an engine, and where the engine is operated at a constant speed and air mass when the fuel injector is operated in the ballistic mode.

13. The method of claim 7, where the fuel fraction is less than 0.5.

14. A method for fueling a cylinder, comprising:

operating an engine at a constant speed and air mass;

supplying a first fuel fraction to a cylinder of the engine via a first fuel injector while supplying a second fuel fraction to the cylinder via a second fuel injector;

increasing a pressure of fuel supplied to the second fuel injector;

decreasing a pulse width supplied to the second fuel injector to operate the second fuel injector in a ballistic region in response to increasing the pressure of fuel supplied to the second fuel injector; and

adjusting a control parameter of the second fuel injector in response to exhaust lambda produced while the second fuel injector is operating in the ballistic region; and

operating the second fuel injector based on the adjusted control parameter.

15. The method of claim 14, where the first fuel injector is a port fuel injector, and where the second fuel injector is a direct fuel injector.

16. The method of claim 14, where the control parameter is further adjusted based on a fraction of fuel supplied to the cylinder via the second fuel injector.

17. The method of claim 16, where the second fuel injector'"'"'s fuel flow is non-linear in the ballistic region.

18. The method of claim 17, where the control parameter is a transfer function or gain.

19. The method of claim 14, further comprising commanding the engine to operate at a constant air-fuel ratio while operating at the constant speed and air mass and while increasing the pressure of fuel supplied to the second fuel injector.

20. The method of claim 14, where the first fuel fraction is greater than 0.5.