System for controlling an internal combustion engine in a fuel efficient manner

• US 6,387,011 B1
• Filed: 02/11/2000
• Issued: 05/14/2002
• Est. Priority Date: 06/18/1998
• Status: Expired due to Term

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Bellinger, Steven M.
• Primary Examiner(s): Marmor, Charles A
• Assistant Examiner(s): HO, HA DINH
• Application Number:
  US09/502,641
• Time in Patent Office: 823 Days
• Field of Search: 477/43, 477/107, 477/110, 477/111, 701/110, 123/350
• US Class Current: 477/111
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2530/10 Weight
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2710/0644 Engine speed
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/1819 Propulsion control with control means using analogue circuits, relays or mechanical links
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 31/009 for maximum speed control
• CPC Class Codes: F02D 41/023 in relation with the gear ratio shifting conjoint control for improving gear change B60W30/19
• CPC Class Codes: F16H 2061/0015 Transmission control for optimising fuel consumptions
• CPC Class Codes: F16H 2061/022 Calculation or estimation of optimal gear ratio, e.g. best ratio for economy drive or performance according driver preference, or to optimise exhaust emissions
• CPC Class Codes: F16H 59/52 dependent on the weight of the machine, e.g. change in weight resulting from passengers boarding a bus
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration

Abstract

A system for controlling an internal combustion engine in a fuel-efficient manner includes a control computer operable to determine a number of engine load/engine speed boundary conditions in relation to an engine output characteristics map and define therefrom an undesirable engine operation region U. As long as the engine is engaged with at least one of the gear ratios of the vehicle transmission, the control computer is operable in one embodiment to maintain engine operation outside of the region U, and in an alternate embodiment to allow operation within the region U but with decreased engine performance/response to thereby encourage operation outside of the region U. The system of the present invention further includes the ability to override, e.g. disable, such engine control based on, for example, certain transmission autoshifting conditions, current vehicle position, and/or information provided from a remote source via a signal transceiver. Using the engine control strategies of the present invention, fuel efficient operation can be optimized, particularly when upshifting through the various transmission gears.

Claims

1. A system for controlling an internal combustion engine, comprising:

a memory having stored therein an engine output characteristics map for an internal combustion engine; and

means for establishing a region of said engine output characteristics map wherein engine operation is undesirable, said region defining a first border as a function of engine speed and a second border intersecting said first border.

2. The system of claim 1 wherein said means for establishing a region of said engine output characteristics map wherein engine operation is undesirable is operable to define a third border of said region, said third border intersecting said second border.

3. The system of claim 2 wherein said third border corresponds to a droop region of said engine output characteristics map.

4. The system of claim 1 further including:

means for establishing a driver reward/penalty; and

means for modifying either of said first and second borders relative to said engine output characteristics map as a function of said driver reward/penalty.

5. The system of claim 1 further including:

means for determining a currently engaged gear ratio of a transmission coupled to said engine and producing a gear ratio value corresponding thereto;

means for determining vehicle speed of a vehicle carrying said engine and producing a vehicle speed signal corresponding thereto; and

means for modifying either of said first and second borders relative to said engine output characteristics map as a function of one of said currently engaged gear ratio value and said vehicle speed signal.

6. The system of claim 1 further including:

means for determining current geographical position of a vehicle carrying said engine; and

means for defining said first and second borders as a function of said current geographical position of said vehicle.

7. The system of claim 2 further including:

means for establishing a driver reward/penalty; and

means for modifying any of said first, second and third borders relative to said engine output characteristics map as a function of said driver reward/penalty.

8. The system of claim 2 further including:

means for determining a currently engaged gear ratio of a transmission coupled to said engine and producing a gear ratio value corresponding thereto;

means for determining vehicle speed of a vehicle carrying said engine and producing a vehicle speed signal corresponding thereto; and

means for modifying any of said first, second and third borders relative to said engine output characteristics map as a function of one of said currently engaged gear ratio value and said vehicle speed signal.

9. The system of claim 2 further including:

means for determining current geographical position of a vehicle carrying said engine; and

means for defining said first, second and third borders as a function of said current geographical position of said vehicle.

10. A method of engine control, comprising the steps of:

establishing in memory an engine output characteristics map for an internal combustion engine;

establishing in memory a first border relative to said engine output characteristics map as a function of engine speed; and

establishing in memory a second border relative to said engine output characteristics map and intersecting said first border, said first and second borders defining a region of said engine output characteristics map wherein engine operation is undesirable.

11. The method of claim 10 wherein the step of establishing in memory a first border includes the steps of:

defining relative to said engine output characteristics map a first engine speed, engine load point;

defining relative to said engine output characteristics map a second engine speed, engine load point; and

defining said first border as a function that intersects said first engine speed, engine load point and said second engine speed, engine load point.

12. The method of claim 10 wherein the step of establishing in memory a first border includes the steps of:

defining relative to said engine output characteristics map an engine speed, engine load point;

defining relative to said engine output characteristics map a boundary slope value; and

defining said first border as a function of said engine speed, engine load point and said boundary slope value.

13. The method of claim 10 wherein the step of establishing in memory a second border includes the step of defining said second border as a function of one of engine load and throttle percentage.

14. The method of claim 10 wherein the step of establishing in memory a second border includes the steps of:

determining a presently engaged gear ratio of a transmission coupled to the engine; and

defining said second border as a function of one of said presently engaged gear ratio.

15. The method of claim 10 further including the step of establishing in memory a third border relative to said engine output characteristics map and intersecting said second border, said first, second and third borders defining said region.

16. The method of claim 15 wherein said third border corresponds to a droop region of said engine output characteristics map.

17. The method of claim 10 wherein the steps of establishing in memory said first and second borders include the steps of:

determining a current geographical position of a vehicle carrying the engine; and

determining the first and second borders as a function of said current geographical position of said vehicle.

18. The method of claim 17 further including the step of establishing in memory a third border relative to said engine output characteristics map as a function of said current geographical position of said vehicle, said third border intersecting said second border, said first, second and third borders defining said region.

19. A system for controlling an internal combustion engine, comprising:

a memory having stored therein an engine output characteristics map and a region thereof of undesirable engine operation, said region having a first border defined as a function of engine speed and a second border intersecting said first border; and

a control computer controlling engine operation according to said engine output characteristics map while maintaining or encouraging engine operation outside said region.

20. The system of claim 19 further including:

means for determining a currently engaged gear ratio of a transmission coupled to said engine and producing a gear ratio value corresponding thereto;

and wherein said control computer is operable to allow engine operation within or on said engine output characteristics map if said gear ratio value corresponds to an invalid gear ratio of said transmission.

21. The system of claim 20 wherein said control computer is operable to allow engine operation anywhere within or on said engine output characteristics map if said gear ratio value corresponds to any of a number of predefined transmission gears.

22. The system of claim 19 further including:

means for determining at least one engine operating condition relating to said engine output characteristics map;

wherein said control computer is operable to compare said at least one engine operating condition with said engine output characteristics map and maintain engine operation outside said region by limiting rotational speed of said engine if said at least one engine operating condition approaches said region.

23. The system of claim 22 wherein said means for determining at least one engine operating condition includes means for determining rotational speed of said engine and producing an engine speed signal corresponding thereto;

and wherein said at least one engine operating condition includes said engine speed signal.

24. The system of claim 23 wherein said means for determining at least one engine operating condition includes means for determining one of engine load and throttle position and producing a load signal corresponding thereto;

and wherein said at least one engine operating condition further includes said load signal.

25. The system of claim 22 wherein said control computer is operable to limit said rotational speed of said engine by limiting said rotational speed to an engine speed along said first boundary.

26. The system of claim 22 wherein said control computer is operable to limit said rotational speed of said engine by limiting said rotational speed to a predefined engine speed defined by said first boundary.

27. The system of claim 22 wherein said control computer is operable to limit said rotational speed of said engine by limiting said rotational speed to a range of engine speeds defined by said first boundary.

28. The system of claim 19 wherein said region of undesirable engine operation further includes a third border intersecting said second border.

29. The system of claim 28 further including:

means for determining at least one engine operating condition relating to said engine output characteristics map;

wherein said control computer is operable to compare said at least one engine operating condition with said engine output characteristics map and limit rotational speed of said engine to an engine speed along said third border if said at least one engine operating condition indicates engine operation at an engine operating condition above engine operating conditions defined by said second border and at an engine operating condition along or beyond engine operating conditions defined by said third border.

30. The system of claim 29 wherein said means for determining at least one engine operating condition includes means for determining rotational speed of said engine and producing an engine speed signal corresponding thereto;

and wherein said at least one engine operating condition includes said engine speed signal.

31. The system of claim 30 wherein said means for determining at least one engine operating condition includes means for determining one of engine load and throttle position and producing a load signal corresponding thereto;

and wherein said at least one engine operating condition further includes said load signal.

32. The system of claim 29 wherein said control computer is further operable to compare said at least one engine operating condition with said engine output characteristics map and limit rotational speed of said engine to an engine speed along said first border after expiration of a predefined time period if said at least one engine operating condition indicates engine operation at an engine operating condition below engine operating conditions defined by said second border and at an engine operating condition at or beyond engine operating conditions defined by said third border.

33. The system of claim 32 wherein said third border corresponds to a droop region of said engine output characteristics map.

34. A method of engine control, comprising the steps of:

providing in memory an engine output characteristics map for an internal combustion engine;

providing in memory a region of said engine output characteristics map of undesirable engine operation, said region having a first border defined as a function of engine speed and a second border intersecting said first border; and

controlling engine operation according to said engine output characteristics map while maintaining or encouraging engine operation outside said region.

35. The method of claim 34 further including the steps of:

determining a currently engaged gear ratio of a transmission coupled to said engine and producing a gear ratio value corresponding thereto; and

allowing engine operation anywhere within or on said engine output characteristics map if said gear ration value corresponds to an invalid gear ratio of said transmission.

36. The method of claim 35 wherein said control computer is operable to allow engine operation anywhere within or on said engine output characteristics map if said gear ratio value corresponds to any of a number of predefined transmission gears.

37. The method of claim 34 further including the steps of:

determining at least one engine operating condition;

comparing said at least one engine operating condition with said engine output characteristics map; and

maintaining engine operation outside said region by limiting rotational speed of said engine if said at least one engine operating condition approaches said region.

38. The method of claim 37 wherein the step of determining at least one engine operating condition includes determining rotational speed of said engine, and wherein said at least one engine operating condition includes said engine speed.

39. The method of claim 38 wherein the step of determining at least one engine operating condition further includes determining one of engine load and throttle position, and wherein said at least one engine operating condition includes one of said engine load and throttle position.

40. A system for controlling an internal combustion engine, comprising:

a memory having stored therein an engine output characteristics map of an internal combustion engine and a region thereof of undesirable engine operation;

means for producing an engine output control override indicator; and

a control computer executing a first engine output control strategy for control engine operation according to said engine output characteristics map while maintaining or encouraging engine operation outside said region as long as said engine output control override indicator is inactive, said control computer otherwise executing a second engine output control strategy for allowing engine operation anywhere within or on said engine output characteristics map.

41. The system of claim 40 wherein said means for producing an engine output control override indicator includes:

a transmission having an autoshift feature wherein said transmission is operable to perform an automatic upshift from one transmission gear to another; and

a transmission control unit having means for producing a first signal corresponding to a pending automatic upshift from one transmission gear to another and means for producing a second signal corresponding to a low load upshift engine speed point relating to said pending automatic upshift;

wherein said control computer is operable to set said engine output control override indicator to inactive unless said transmission control unit produces said first and second signals.

42. The system of claim 41 wherein said transmission control unit further includes means for producing a third signal corresponding to completion of said pending upshift;

and wherein said control computer is operable to reset said engine output control override indicator to inactive when said transmission control unit produces said third signal after producing said first and second signals.

43. The system of claim 40 wherein said means for producing an engine output control override indicator includes:

a global positioning system (GPS) producing GPS coordinates corresponding to a present position of a vehicle carrying said engine;

wherein said control computer is responsive to said GPS coordinates to set said engine output control override indicator to inactive as long as said GPS coordinates correspond to a vehicle position where said first engine control strategy is appropriate.

44. The system of claim 40 wherein said means for producing an engine output control override indicator includes:

a signal transceiver operable to receive communication signals from a remote system;

wherein said control computer is responsive to said communication signals to set said engine output control override indicator to inactive as long as said communication signals indicate that said first engine control strategy is appropriate.