System and method for detecting cylinder misfire

• US 7,788,020 B2
• Filed: 03/11/2008
• Issued: 08/31/2010
• Est. Priority Date: 03/11/2008
• Status: Expired due to Fees

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Johnson, Thomas M., Wolf, Adam J., Klingaman, Wes
• Primary Examiner(s): Cronin; Stephen K
• Assistant Examiner(s): Castro; Arnold
• Application Number:
  US12/046,036
• Publication Number:
  US 20090234562A1
• Time in Patent Office: 903 Days
• Field of Search: 701/103, 701/108, 701/111, 731/140.6
• US Class Current: 701/108
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 2400/08 Redundant elements, e.g. two sensors for measuring the same parameter
• CPC Class Codes: F02D 41/0072 Estimating, calculating or determining the EGR rate, amount or flow sensors in EGR systems F02M26/45
• CPC Class Codes: F02D 41/008 Controlling each cylinder individually
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: G01M 15/11 by detecting misfire
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A system for detecting individual cylinder misfire in a multiple cylinder internal combustion (IC) engine having exhaust gas recirculation (EGR). The system includes: a device for predicting EGR flow rate on a cylinder to cylinder basis; a device for sensing actual EGR flow rate on a cylinder to cylinder basis with all cylinders firing; and a device for comparing the predicted EGR flow rate to the actual EGR flow to determine individual cylinder misfire.

Claims

1. A system for detecting individual cylinder misfire in a multiple cylinder internal combustion (IC) engine having an exhaust gas recirculation (EGR) system, said misfire detection system comprising:

a device for predicting EGR flow rate on a cylinder to cylinder basis;

a device for sensing actual EGR flow rate on a cylinder to cylinder basis with all cylinders firing; and

a device for comparing the predicted EGR flow rate to the actual EGR flow to determine individual cylinder misfire.

2. The system as claimed in claim 1, wherein said engine includes a fuel system and an engine electronic control module (ECU) and said system further comprises a combustion management strategy within said ECU to correct misfire.

3. The system as claimed in claim 2, wherein said combustion management strategy is one of at least adjusting fuel rate and quantity and combustion timing.

4. The system as claimed in claim 1, wherein said EGR flow rate is detected by a device sensing differential pressure across an obstruction.

5. The system as claimed in claim 4 wherein said device is one of a venturi, orifice, nozzle, segmental wedge, V-cone and Dall tube.

6. The system as claimed in claim 5 wherein said device is a venturi.

7. The system as claimed in claim 5 wherein said device is an orifice.

8. The system as claimed in claim 2, wherein said engine has a crank angle sensor to correlate the crank angle to activity in individual cylinders.

9. The system as claimed in claim 8, wherein said device for comparing predicted and actual EGR flow stores a history of EGR flow to predict current EGR flow.

10. The system as claimed in claim 9, wherein said corrected action is one of adjusting fueling rate and/or quantity and combustion timing.

11. A method of determining individual cylinder misfiring in a multiple cylinder internal combustion engine (IC) engine having an exhaust gas recirculation (EGR) system comprising the steps of:

predicting EGR flow rate on a cylinder to cylinder basis with all cylinders firing;

sensing actual EGR flow rate on a cylinder to cylinder basis; and

comparing the predicted EGR flow rate to the actual EGR flow rate to determine individual cylinder misfiring.

12. The method as claimed in claim 11, wherein said internal combustion engine has a fuel system and electronic control unit (ECU) and wherein said method comprises the further step of correcting misfire determined by said system.

13. The method as claimed in claim 12, wherein said corrected step is one of adjusting fueling rate and/or quantity and combustion timing.

14. The method as claimed in claim 11, wherein said EGR flow rate is detected by a device sensing differential pressure across an obstruction.

15. The method as claimed in claim 14 wherein said device is one of a venturi, orifice, nozzle, segmental wedge, V-cone and Dall tube.

16. The method as claimed in claim 15 wherein said device is a venturi.

17. The method as claimed in claim 15 wherein said device is an orifice.

18. The method as claimed in claim 11, comprising the further step of correlating the crank angle of the engine to individual cylinder conditions.

19. The method as claimed in claim 18, comprising the further step of storing the history of EGR flow and comparing actual EGR flow to correct predicted EGR flow.