Method for improved performance of a vehicle

• US 6,327,847 B1
• Filed: 03/17/2000
• Issued: 12/11/2001
• Est. Priority Date: 03/17/2000
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Surnilla, Gopichandra, Bidner, David Karl
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): TRAN, DIEM T
• Application Number:
  US09/528,147
• Time in Patent Office: 634 Days
• Field of Search: 602/74, 602/77, 602/85, 602/95, 603/01
• US Class Current: 60/274
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 11/007 the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus
• CPC Class Codes: F01N 13/009 having two or more separate purifying devices arranged in series
• CPC Class Codes: F01N 2250/12 absorption or adsorption, and catalytic conversion
• CPC Class Codes: F01N 2430/06 by varying fuel-air ratio, e.g. by enriching fuel-air mixture
• CPC Class Codes: F01N 2550/03 of sorbing activity of adsorbents or absorbents
• CPC Class Codes: F01N 2560/026 for measuring or detecting NOx
• CPC Class Codes: F01N 2570/04 Sulfur or sulfur oxides
• CPC Class Codes: F01N 3/0814 combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
• CPC Class Codes: F01N 3/0842 Nitrogen oxides
• CPC Class Codes: F01N 3/0864 Oxygen
• CPC Class Codes: F01N 9/005 using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly
• CPC Class Codes: F02D 2200/0625 Fuel consumption, e.g. measured in fuel liters per 100 kms or miles per gallon
• CPC Class Codes: F02D 41/0275 the exhaust gas treating apparatus being a NOx trap or adsorbent
• CPC Class Codes: F02D 41/028 Desulfurisation of NOx traps or adsorbent
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An engine control system for managing lean NOx trap decontamination uses associated fuel economy impacts to determine when decontamination is enabled. In particular, a maximum achievable benefit provided by lean operation with a decontaminated NOx trap, a present fuel economy benefit being provided by lean operation, and a fuel economy penalty for performing decontamination are used. When a resulting benefit is greater than a penalty, decontamination is enabled.

Claims

1. A method of determining performance of an emission control device coupled to an internal combustion engine, the emission control device susceptible to contamination, the method comprising:

performing a decontamination cycle;

after said decontamination cycle, measuring a benefit of both operating lean of stoichiometry for first a first interval and operating near stoichiometry or rich of stoichiometry for a second interval, wherein said first interval is greater than said second interval, wherein said first interval is greater than said second interval.

2. The method recited in claim 1 wherein said benefit is a fuel economy benefit.

3. The method recited in claim 1 wherein said benefit is relative to near stoichiometric operation.

4. The method recited in claim 1 further comprising enabling future decontamination cycles based on said benefit.

5. The method recited in claim 1 where said measuring further comprises measuring said benefit based on fuel savings during said first interval and fuel loss during said second interval.

6. A method of determining performance of an emission control device coupled to an internal combustion engine, the emission control device susceptible to contamination, the method comprising:

performing a decontamination cycle;

after said decontamination cycle, measuring a benefit of both operating lean of stoichiometry for first a first interval and operating near stoichiometry or rich of stoichiometry for a second interval, wherein said benefit is a ratio of an amount of fuel saved to a distance traveled.

7. The method recited in claim 6 wherein said benefit is relative to near stoichiometric operation.

8. The method recited in claim 6 further comprising enabling future decontamination cycles based on said benefit.

9. The method recited in claim 6 wherein said measuring further comprises measuring said benefit based on fuel savings during said first interval and fuel loss during said second interval.

10. A method of determining performance of an emission control device coupled to an internal combustion engine, the emission control device susceptible to contamination, the method comprising:

performing a decontamination cycle;

after said decontamination cycle, measuring a benefit of both operating lean of stoichiometry for first a first interval and operating near stoichiometry or rich of stoichiometry for a second interval, wherein said benefit is a maximum achievable benefit when the reversible contamination is removed, wherein the emission control device stores NOx when during said first interval and the emission control device releases and reduces stored NOx during the second interval; and

determining a filtered benefit after several decontamination cycles based on said maximum achievable benefit.

11. A method of determining performance of an emission control device coupled to an internal combustion engine, the emission control device susceptible to contamination, the method comprising:

performing a decontamination cycle;

after said decontamination cycle, measuring a benefit of both operating lean of stoichiometry for first a first interval and operating near stoichiometry or rich of stoichiometry for a second interval, wherein said benefit is based on an engine torque ratio when operating lean of stoichiometry.

12. A method of determining maximum performance of an emission control device coupled to an internal combustion engine, the emission control device susceptible to contamination, the method comprising:

performing a decontamination cycle;

after said decontamination cycle, measuring a maximum achievable fuel economy benefit of both operating lean of stoichiometry for first a first interval where the emission control device stores NOx and operating near stoichiometry or rich of stoichiometry for a second interval where the emission control device reduces stored NOx, wherein said measuring is performed when the contamination is removed;

enabling future decontamination cycles based on said maximum achievable benefit; and

determining a filtered benefit after several decontamination cycles based on said maximum achievable benefit.

13. An article of manufacture comprising:

a computer storage medium having a computer program encoded therein for determining maximum performance of an emission control device coupled to an internal combustion engine, the emission control device susceptible to contamination, said computer storage medium comprising;

code for performing a decontamination cycle;

code for measuring a maximum achievable fuel economy benefit of both operating the engine lean of stoichiometry for first a first interval and operating the engine near stoichiometry or rich of stoichiometry for a second interval, wherein said measuring is performed after said decontamination cycle; and

code for determining a filtered benefit after several decontamination cycles based on said maximum achievable benefit.

14. The article recited in claim 13 further comprising code for enabling future decontamination cycles based on said maximum achievable fuel economy benefit.

15. The article recited in claim 13 further comprising code for enabling future decontamination cycles based on said filtered benefit.

16. The article recited in claim 13 wherein said emission control device is a NOx trap.