Air/fuel ratio control using a display interface

• US 20040107039A1
• Filed: 12/03/2002
• Published: 06/03/2004
• Est. Priority Date: 12/03/2002
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Hasler, Greg, Zwetz, Dave
• Granted Patent: US 6,947,823 B2
• Time in Patent Office: Days
• 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. 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 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.

2. A method, as set forth in claim 1, 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.

3. A method, as set forth in claim 2, wherein monitoring an amount of smoke being emitted includes the step of visually monitoring an amount of smoke being emitted.

4. A method, as set forth in claim 1, 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.

5. A method, as set forth in claim 1, 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.

6. A method, as set forth in claim 5, 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.

7. A method, as set forth in claim 1, 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.

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

a programmable controller electrically connected to the engine;

a coarse air/fuel ratio setting 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.

9. An apparatus, as set forth in claim 8, 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.

10. An apparatus, as set forth in claim 9, wherein the display is a display of a range from the maximum to the minimum air/fuel ratio maps.

11. An apparatus, as set forth in claim 10, 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.

12. 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.

13. A display interface, as set forth in claim 12, wherein the display indication includes a graphical indication of the range from the maximum to the minimum air/fuel ratio.

14. A display interface, as set forth in claim 13, wherein the input interface includes an up/down selection to select the fine air/fuel ratio.

15. 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; and

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

16. 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.

17. A method, as set forth in claim 16, further including the step of selecting a value of fuel delivery within the range for fixed values of engine speed and engine boost pressure.