Control strategy for an internal combustion engine in a hybrid vehicle

• US 20030033074A1
• Filed: 05/29/2002
• Published: 02/13/2003
• Est. Priority Date: 08/09/2001
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lippa, Allan J., Xu, Lifeng, Brehob, Diana D., Yang, Jialin
• Granted Patent: US 7,110,904 B2
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: B60H 1/3208 Vehicle drive related control of the compressor drive means, e.g. for fuel saving purposes
• CPC Class Codes: B60K 6/08 Prime-movers comprising combustion engines and mechanical or fluid energy storing means
• CPC Class Codes: B60K 6/10 by means of a chargeable mechanical accumulator, e.g. flywheel
• CPC Class Codes: B60K 6/105 the accumulator being a flywheel
• CPC Class Codes: B60K 6/12 by means of a chargeable fluidic accumulator
• CPC Class Codes: B60K 6/445 Differential gearing distribution type
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/15 Control strategies specially adapted for achieving a particular effect
• CPC Class Codes: B60W 2510/0671 Engine manifold pressure
• CPC Class Codes: B60W 2510/068 Engine exhaust temperature
• CPC Class Codes: B60W 2710/0622 Air-fuel ratio
• CPC Class Codes: B60Y 2300/476 Regeneration of particle filters
• CPC Class Codes: F01N 2570/04 Sulfur or sulfur oxides
• CPC Class Codes: F01N 2570/14 Nitrogen oxides
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/03 the substance being hydrocarbons, e.g. engine fuel
• CPC Class Codes: F01N 3/023 using means for regenerating the filters, e.g. by burning trapped particles by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235
• CPC Class Codes: F02D 2250/18 : Control of the engine output torque
• CPC Class Codes: F02D 41/027 : to purge or regenerate the exhaust gas treating apparatus
• CPC Class Codes: F02D 41/083 : taking into account engine load variation, e.g. air-conditionning
• CPC Class Codes: Y02T 10/12 : Improving ICE efficiencies
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles

Abstract

A system and method is disclosed for operating an internal combustion engine disposed in a hybrid vehicle, in which engine operation is selected to provide secondary vehicular functions, such as cabin heating, cabin cooling, and exhaust aftertreatment of exhaust components.

Claims

1. A vehicle system comprising:

at least two machines capable of being coupled to driving wheels of the vehicle, one of said machines being an internal combustion engine;

at least one engine dependent auxiliary device coupled to said engine; and

an engine controller operably connected to said machines to determine when said engine dependent auxiliary device should be attended to and to determine whether a current engine operating condition is within an acceptable engine operating range which satisfies said engine dependent auxiliary device.

2. The system of claim 1 wherein said engine controller determines a desired engine operating condition which satisfies said engine dependent auxiliary device and commands said engine to attain said desired engine operating condition when said current engine operating condition is not within said acceptable engine operating range.

3. The system of claim 1 wherein said engine dependent auxiliary device is a catalyst coupled to said engine.

4. The system of claim 1 wherein said catalyst comprises a lean NOx catalyst for reducing NOx when the engine air/fuel ratio is lean of stoichiometry.

5. The system of claim 4 wherein said acceptable engine operating range provides a NOx concentration in an exhaust gas stream discharged from the engine less than a predetermined NOx concentration.

6. The system of claim 5 wherein said predetermined NOx concentration is 25 ppm.

7. The system of claim 3 wherein said acceptable engine operating range provides a temperature of said catalyst greater than a predetermined temperature.

8. The system of claim 7 wherein said predetermined temperature is 300 degrees Celsius.

9. The system of claim 3 further comprising an injector for supplying a reductant into an exhaust stream of said engine upstream of said catalyst.

10. The system of claim 9 wherein said engine controller is coupled to said injector and commands said injector to supply reductant in the event that said current operating condition is within said acceptable operating range or substantially at said desired operating condition.

11. The system of claim 1 wherein said engine dependent auxiliary device is a particulate filter coupled to said engine.

12. The system of claim 11 wherein said acceptable operating condition range provides a temperature in said particulate filter to exceed an ignition temperature of particulate matter filtered in said particulate filter.

13. The system of claim 1 wherein said engine dependent auxiliary device is an air conditioning system coupled to the engine.

14. The system of claim 13 wherein said acceptable operating condition range is substantially an operating condition which provides a high thermal efficiency of the engine.

15. The system of claim 1 wherein said engine dependent auxiliary device is a cabin heating system provided in the vehicle.

16. The system of claim 1 wherein said engine dependent auxiliary device is a fuel vapor purge system coupled to said engine.

17. The system of claim 1 wherein said acceptable operating condition range is an operating condition range providing a manifold vacuum greater than 5 kPa.

18. The system of claim 1 wherein said engine dependent auxiliary device is a lean NOx trap coupled to said engine.

19. The system of claim 1 further comprising an energy reservoir coupled to said secondary machine, wherein said secondary machine is one of said machines other than said internal combustion engine.

20. The system of claim 19 wherein said secondary machine may generate energy which may be stored in said energy reservoir.

21. The system of claim 19 wherein said secondary machine may remove energy stored in said energy reservoir.

22. The system of claim 20 wherein said energy reservoir may comprise a battery, a flywheel, a hydraulic fluid reservoir, a thermal reservoir, a spring, or a capacitor.

23. A method to control a vehicle system having a primary machine, which is an internal combustion engine, and at least one secondary machine and said machines are capable of being coupled to driving wheels of the vehicle, comprising the steps of:

determining that an engine dependent auxiliary device should be attended to;

determining a desired engine operating condition that satisfies said engine dependent auxiliary device; and

commanding the engine to attain said desired engine operating condition.

24. The method of claim 23 further comprising the steps of:

determining a desired power at the driving wheels desired by an operator of the vehicle;

determining an engine provided power at the driving wheels based on said engine desired operating condition;

causing the secondary machine to absorb a difference between said engine provided power and said desired power when said engine provided power is greater than said desired power; and

causing the secondary machine to supply a difference between said desired power and said engine provided power when said engine provided power is less than said desired power.

25. The method of claim 23 further comprising the step of attending to said engine dependent auxiliary device.

26. The method according to claim 25 further comprising the steps of:

determining a maximum power at the driving wheels that the secondary machine may provide; and

postponing said commanding step when a sum of said maximum power and said engine provided power are less than said desired power.

27. The method according to claim 25 further comprising the steps of:

determining a maximum absorption power that the secondary machine may absorb;

postponing said commanding step when a difference of said engine provided power and said desired power exceeds said maximum absorption power.

28. The method according to claim 23 wherein said desired engine operating condition may be the engine not operating.

29. The method according to claim 23 wherein said desired operating condition may be an engine speed and torque condition which provides substantially a highest thermal efficiency, in the event that said engine dependent auxiliary device is coupled by a gear, belt, or chain drive to said engine.

30. The method according to claim 23 wherein the internal combustion engine includes and intake manifold.

31. The method according to claim 30 wherein said engine dependent auxiliary device comprises a device requiring a vacuum in the intake manifold.

32. The method according to claim 31 wherein said step of determining a desired engine operating condition comprises generating a vacuum in said intake manifold.

33. A computer readable storage medium having stored data representing instructions executable by a computer to control a vehicle system, the vehicle system comprises at least two machines capable of being coupled to the vehicle, one of the machines being an internal combustion engine, comprising:

instructions for determining whether an engine dependent auxiliary device should be attended to; and

instructions for determining whether a current engine operating condition is within an acceptable engine operating range which satisfies said engine dependent auxiliary device.

34. The computer readable storage medium of claim 33 further comprising instructions for determining a desired engine operating condition which satisfies said engine dependent auxiliary device, when said current engine operating condition is not within said acceptable engine operating range.

35. The computer readable storage medium of claim 34 further comprising instructions for causing said engine to attain said desired engine operating condition.

36. The computer readable storage medium of claim 33 further comprising instructions for attending to said engine dependent auxiliary device if said current engine operating condition is within said acceptable engine operating range.

37. The computer readable storage medium of claim 35 further comprising instructions for attending to said engine dependent auxiliary device when said current engine operating condition is substantially similar to said desired engine operating condition.