Dynamic engine timing control

• US 6,732,709 B1
• Filed: 12/06/2002
• Issued: 05/11/2004
• Est. Priority Date: 12/06/2002
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Harris, James W., Zadoks, Rick I., Havran, Richard L.
• Primary Examiner(s): Mohanty, Bibhu
• Application Number:
  US10/313,180
• Time in Patent Office: 522 Days
• Field of Search: 123/406.24, 123/406.41, 123/406.35, 123/406.36, 123/406.18, 123/406.12, 123/406.61
• US Class Current: 123/406.24
• CPC Class Codes: F02D 2250/28 Control for reducing torsional vibrations, e.g. at acceleration
• CPC Class Codes: F02D 41/009 using means for generating position or synchronisation signals
• CPC Class Codes: F02D 41/401 Controlling injection timing F02D41/402 takes precedence
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A method and apparatus for controlling timing of an internal combustion engine having a piston located in a cylinder. The method and apparatus includes determining a first angular position of a crankshaft at a first location along a longitudinal axis of the crankshaft, determining a second angular position of the crankshaft at a second location along the longitudinal axis, determining a level of deformation of the crankshaft as a function of a difference between the first and second angular positions, determining an actual position of the piston as a function of the crankshaft deformation, comparing the actual piston position to a desired piston position, and controlling timing of an event to initiate combustion in the cylinder as a function of a difference between the actual and desired piston positions.

Claims

1. A method for controlling timing of an internal combustion engine having a piston located in a cylinder, the piston being drivably connected to a crankshaft, including the steps of:

determining a first angular position of the crankshaft at a first location along a longitudinal axis of the crankshaft;

determining a second angular position of the crankshaft at a second location along the longitudinal axis;

determining a level of deformation of the crankshaft as a function of a difference between the first and second angular positions;

determining an actual position of the piston as a function of the crankshaft deformation;

comparing the actual piston position to a desired piston position; and

controlling timing of an event to initiate combustion in the cylinder as a function of a difference between the actual and desired piston positions.

2. A method, as set forth in claim 1, wherein determining a first and a second angular position includes the steps of sensing a first and second angular position of the crankshaft.

3. A method, as set forth in claim 1, wherein determining a level of deformation of the crankshaft includes the step of determining an angular deformation of the crankshaft.

4. A method, as set forth in claim 3, wherein determining an angular deformation of the crankshaft includes the step of determining an amount of angular deformation at a predetermined location along the longitudinal axis of the crankshaft.

5. A method, as set forth in claim 1, wherein determining an actual position of the piston includes the step of determining an actual piston position with respect to a top dead center position in the cylinder.

6. A method, as set forth in claim 1, wherein controlling timing of an event includes the step of controlling timing of at least one of a fuel injection event and an ignition event.

7. A method for controlling timing of an internal combustion engine having a plurality of pistons each located in a corresponding one of a plurality of cylinders, each piston being drivably connected to a crankshaft, including the steps of:

determining a first angular position of the crankshaft at a first location along a longitudinal axis of the crankshaft;

determining a second angular position of the crankshaft at a second location along the longitudinal axis;

determining a level of deformation of the crankshaft as a function of a difference between the first and second angular positions;

determining an actual position of each piston as a function of the crankshaft deformation;

comparing each actual piston position to a corresponding desired piston position; and

controlling timing of an event to initiate combustion in each cylinder as a function of a difference between the actual and desired piston positions.

8. A method, as set forth in claim 7, wherein determining a first and a second angular position includes the steps of sensing a first and second angular position of the crankshaft.

9. A method, as set forth in claim 7, wherein determining a level of deformation of the crankshaft includes the step of determining an angular deformation of the crankshaft.

10. A method, as set forth in claim 9, wherein determining an angular deformation of the crankshaft includes the step of determining an amount of angular deformation at predetermined locations along the longitudinal axis of the crankshaft.

11. A method, as set forth in claim 7, wherein determining an actual position of each piston includes the step of determining actual piston positions with respect to a top dead center position in each corresponding cylinder.

12. A method, as set forth in claim 7, wherein controlling timing of an event includes the step of controlling timing of at least one of a fuel injection event and an ignition event in each cylinder.

13. An apparatus for controlling timing of an internal combustion engine having a piston located in a cylinder, the piston being drivably connected to a crankshaft, comprising:

a first crankshaft angular position determiner located to determine an angular position at a first location along a longitudinal axis of the crankshaft;

a second crankshaft angular position determiner located to determine an angular position at a second location along the longitudinal axis; and

a controller for determining a level of deformation of the crankshaft as a function of a difference between the first and second angular positions, determining an actual position of the piston as a function of the crankshaft deformation, comparing the actual piston position to a desired piston position, and controlling timing of an event to initiate combustion in the cylinder as a function of a difference between the actual and desired piston positions.

14. An apparatus, as set forth in claim 13, further including a plurality of pistons each located in a corresponding one of a plurality of cylinders, each piston being drivably connected to the crankshaft.

15. An apparatus, as set forth in claim 14, wherein the controller is further configured for determining an actual position of each piston as a function of the crankshaft deformation, comparing each actual piston position to a corresponding desired piston position, and controlling timing of an event to initiate combustion in each cylinder as a function of a difference between the actual and desired piston positions.

16. An apparatus, as set forth in claim 13, wherein the first crankshaft angular position determiner includes a crankshaft angular position sensor.

17. An apparatus, as set forth in claim 13, wherein the second crankshaft angular position determiner includes a crankshaft angular position sensor.

18. An apparatus, as set forth in claim 13, wherein the first and second crankshaft angular position determiners include respective first and second crankshaft angular position sensors.

19. An apparatus, as set forth in claim 18, wherein the first crankshaft angular position sensor is located at a first position along the longitudinal axis, and the second crankshaft angular position sensor is located at a second position along the longitudinal axis.

20. An apparatus, as set forth in claim 19, wherein the first crankshaft angular position sensor is located at a first end of the crankshaft, and the second crankshaft angular position sensor is located at a second end of the crankshaft.

21. An apparatus, as set forth in claim 14, wherein at least one of the first and second crankshaft angular position determiners includes:

a piston position detector for determining a position of one of the plurality of pistons; and

means for determining the angular position at a corresponding at least one of the first and second crankshaft locations as a function of the piston position.

22. An apparatus, as set forth in claim 21, wherein the piston position detector includes a cylinder pressure sensor.

23. An apparatus for controlling cylinder-to-cylinder timing in an internal combustion engine, comprising:

a crankshaft located in the engine;

a plurality of connecting rods each having a first end connected to the crankshaft;

a plurality of pistons each connected to a second end of a corresponding one of the plurality of connecting rods such that each piston is configured to drivably engage the crankshaft;

a plurality of cylinders located in the engine, each piston being slidably positioned within a corresponding cylinder;

a first angular position sensor located at a first location along a longitudinal axis of the crankshaft;

a second angular position sensor located at a second location along the longitudinal axis; and

a controller electrically connected to the first and second angular position sensors;

wherein the controller receives signals from the first and second angular position sensors indicative of angular positions of the respective first and second locations along the longitudinal axis, determines a level of deformation of the crankshaft, determines an actual position of each piston as a function of the crankshaft deformation, and controls timing of an event to initiate combustion in each cylinder as a function of a difference of each actual piston position from each corresponding desired piston position.

24. An apparatus, as set forth in claim 23, wherein an event to initiate combustion includes a start of injection of fuel.

25. An apparatus, as set forth in claim 23, wherein an event to initiate combustion includes an ignition of fuel.