Air/fuel ratio control using a display interface

• US 6,947,823 B2
• Filed: 12/03/2002
• Issued: 09/20/2005
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Hasler, Greg, Zwetz, Dave
• Primary Examiner(s): Vo, Hieu T.
• Application Number:
  US10/308,838
• Publication Number:
  US 20040107039A1
• Time in Patent Office: 1,022 Days
• Field of Search: 701/103, 701/115, 701/102, 731/173, 731/16, 73/232.3, 731/181, 123/480, 123/486
• US Class Current: 701/103
• CPC Class Codes: F02D 2041/228 Warning displays
• CPC Class Codes: F02D 41/1475 Regulating the air fuel ratio at a value other than stoichiometry
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02D 41/3005 Details not otherwise provided for

Abstract

A method and apparatus for controlling an air/fuel ratio of an internal combustion engine having a programmable air/fuel ratio control. The method and apparatus includes pre-programming a coarse air/fuel ratio setting, determining a condition of the air/fuel ratio being at an undesired value, and programming a fine air/fuel ratio setting using a display interface.

Claims

1. An apparatus for controlling an air/fuel ratio of an internal combustion engine, comprising:

a programmable controller electrically connected to the engine;

coarse air/fuel ratio settings which are based at least in part on engine speed, programmed into the controller;

a display electrically connected to the controller; and

an input device interfaced with the display to provide input of a fine air/fuel ratio to the controller.

2. An apparatus, as set forth in claim 1, wherein the coarse air/fuel ratio setting includes:

a maximum air/fuel ratio map programmed into the controller; and

a minimum air/fuel ratio map programmed into the controller.

3. An apparatus, as set forth in claim 2, wherein the display is a display of a range from the maximum to the minimum air/fuel ratio maps.

4. An apparatus, as set forth in claim 3, wherein the input device is configured to select a fine air/fuel ratio within the range from the maximum to the minimum air/fuel ratio maps.

5. The apparatus of claim 1 wherein the display includes an electronic display to an operator of an available air/fuel ratio range.

6. A display interface for providing control of an air/fuel ratio of an internal combustion engine, comprising:

a display indication of a range from a maximum to a minimum air/fuel ratio; and

an input interface connected to the display for selecting a fine air/fuel ratio from within the range.

7. A display interface, as set forth in claim 6, wherein the display indication includes a graphical indication of the range from the maximum to the minimum air/fuel ratio.

8. A display interface, as set forth in claim 7, wherein the input interface includes an up/down selection to select the fine air/fuel ratio.

9. A method for providing operator control of an air/fuel ratio of an engine having a pre-programmed coarse air/fuel ratio setting, including the steps of:

visually monitoring an amount of smoke being emitted from the engine;

determining a condition of an undesired value of air/fuel ratio as a function of the monitored smoke;

displaying to an operator an available air/fuel ratio range of selection; and

inputting into a display interface a fine air/fuel ratio setting to adjust the air/fuel ratio to a desired value.

10. A method for controlling an air/fuel ratio of an internal combustion engine having a programmable air/fuel ratio control, including the steps of:

programming a three-dimensional maximum air/fuel ratio map as a function of engine speed, engine boost pressure, and fuel delivery;

programming a three-dimensional minimum air/fuel ratio map as a function of engine speed, engine boost pressure, and fuel delivery; and

determining a range from the maximum to the minimum air/fuel ratio maps.

11. A method, as set forth in claim 10, further including the step of selecting a value of fuel delivery within the range for fixed values of engine speed and engine boost pressure.

12. The method of claim 10 further comprising the step of displaying to an operator an available air/fuel ratio range of selection.

13. A method for controlling an air/fuel ratio of an internal combustion engine having a programmable air/fuel ratio control, including the steps of:

pre-programming coarse air/fuel ratio settings which are based at least in part on engine speed;

determining a condition of the air/fuel ratio being at an undesired value; and

programming a fine air/fuel ratio setting using a display interface.

14. A method, as set forth in claim 13, wherein determining a condition of the air/fuel ratio being at an undesired value includes the step of monitoring an amount of smoke emitting from the engine.

15. A method, as set forth in claim 14, wherein monitoring an amount of smoke being emitted includes the step of visually monitoring an amount of smoke being emitted.

16. A method, as set forth in claim 13, wherein programming a fine air/fuel ratio setting includes the step of programming an air/fuel ratio setting within a range of pre-programmed air/fuel ratio coarse settings.

17. A method, as set forth in claim 13, wherein programming a fine air/fuel ratio setting includes the step of programming a fine air/fuel ratio setting during normal operation of the engine.

18. A method, as set forth in claim 17, wherein programming a fine air/fuel ratio setting includes the step of programming a fine air/fuel ratio setting by an operator of the engine.

19. A method, as set forth in claim 13, wherein pre-programming a coarse air/fuel setting includes the steps of:

programming a three-dimensional maximum air/fuel ratio map as a function of engine speed, engine boost pressure, and fuel delivery;

programming a three-dimensional minimum air/fuel ratio map as a function of engine speed, engine boost pressure, and fuel delivery; and

determining a range from the maximum to the minimum air/fuel ratio maps.

20. The method of claim 13 further comprising the step of displaying to an operator an available air/fuel ratio range of selection.