System for diagnosing an air handling mechanism of an internal combustion engine

• US 6,687,601 B2
• Filed: 03/21/2002
• Issued: 02/03/2004
• Est. Priority Date: 03/21/2002
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Wang, Yue Yun, Bale, Carlton
• Primary Examiner(s): WOLFE JR, WILLIS RAY
• Application Number:
  US10/103,638
• Publication Number:
  US 20030182049A1
• Time in Patent Office: 684 Days
• Field of Search: 701/100, 701/101, 701/102, 701/103, 701/107, 701/108, 701/114, 701/29, 701/34, 123/568.11, 123/568.12, 123/568.16, 123/568.21, 731/173, 731/181, 731/182, 606/02, 606/052, 603/24
• US Class Current: 701/108
• CPC Class Codes: F02B 29/0406 Layout of the intake air cooling or coolant circuit
• CPC Class Codes: F02B 29/0493 Controlling the air charge temperature
• 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 26/23 Layout, e.g. schematics
• CPC Class Codes: F02M 26/33 controlling the temperature of the recirculated gases
• CPC Class Codes: F02M 26/47 the characteristics being temperatures, pressures or flow rates
• CPC Class Codes: F02M 26/48 EGR valve position sensors details of the sensor installation in the valve housing F02M26/72
• CPC Class Codes: F02M 26/72 Housings

Abstract

A system for diagnosing an air handling mechanism of an internal combustion engine includes an air handling mechanism actuator, an air handling mechanism position sensor, a sensor associated with an engine operating condition separate from the air handling mechanism yet responsive to changes in the position of the mechanism actuator, and a control computer. The control computer is responsive to the position sensor signal and the engine operating condition sensor to diagnose faults/failure conditions associated with any of the air handling mechanism, the mechanism position sensor and the mechanism actuator. The air handling mechanism may be any of an EGR valve, a variable geometry turbocharger, a wastegate valve and an exhaust throttle, and the engine operating condition sensor may be associate with any of air intake pressure, air intake temperature, mass flow rate of intake air, exhaust gas pressure, EGR mass flow rate or turbocharger speed.

Claims

1. A diagnostic system for an air handling mechanism of an air handling system for an internal combustion engine, the system comprising:

an actuator responsive to an actuator command to control position of the air handling mechanism;

a first sensor producing a first signal indicative of a position of the air handling mechanism relative to a reference position;

a second sensor producing a second signal indicative of an operation of another component of the air handling system separate from, yet responsive to changes in the position of, the air handling mechanism; and

a control computer producing said actuator command, said control computer thereafter diagnosing an operating condition of said air handling mechanism as a function of said first and second signals.

2. The system of claim 1 wherein said first signal corresponds to a position of said actuator relative to a reference actuator position.

3. The system of claim 1 wherein said control computer is operable to determine that the air handling mechanism is operating normally if, after producing said actuator command, said first signal indicates that the position of the air handling mechanism is within a threshold value of the position corresponding to the actuator command and the second signal indicates that the operation of the another component of the air handling system is within a range of expected operational values.

4. The system of claim 1 wherein said control computer is operable to determine a fault associated with said first sensor if, after producing said actuator command, said first signal indicates that the position of the air handling mechanism is within a threshold value of the position corresponding to the actuator command and the second signal indicates that the operation of the another component of the air handling system is outside of a range of expected operational values.

5. The system of claim 4 further including a memory, said control computer logging a fault code within said memory corresponding to said fault associated with said first sensor.

6. The system of claim 4 further including at least one warning indicator, said control computer activating said at least one warning indicator upon detection of said fault associated with said first sensor.

7. The system of claim 1 wherein said control computer is operable to determine a fault associated with the air handling mechanism if, after producing said actuator command, said first signal indicates that the position of the air handling mechanism is not within a threshold value of the position corresponding to the actuator command and the second signal indicates that the operation of the another component of the air handling system is within a range of expected operational values.

8. The system of claim 7 further including a memory, said control computer logging a fault code within said memory corresponding to said fault associated with the air handling mechanism.

9. The system of claim 7 further including at least one warning indicator, said control computer activating said at least one warning indicator upon detection of said fault associated with the air handling mechanism.

10. The system of claim 1 wherein said control computer is operable to determine a fault associated with the said actuator if, after producing said actuator command, said first signal indicates that the position of the air handling mechanism is not within a threshold value of the position corresponding to the actuator command and the second signal indicates that the operation of the another component of the air handling system is outside of a range of expected operational values.

11. The system of claim 10 further including a memory, said control computer logging a fault code within said memory corresponding to said fault associated with said actuator.

12. The system of claim 10 further including at least one warning indicator, said control computer activating said at least one warning indicator upon detection of said fault associated with said actuator.

13. The system of claim 1 wherein the air handling mechanism is an EGR valve controlling a flow of exhaust gas from an exhaust manifold of the engine to an intake manifold of the engine;

and wherein said first signal corresponds to a position of said EGR valve relative to a reference EGR valve position.

14. The system of claim 13 wherein said second sensor is a speed sensor coupled to a turbocharger disposed in fluid communication with said intake and exhaust manifolds, said second signal indicative of rotational speed of said turbocharger.

15. The system of claim 13 wherein said second sensor is a pressure sensor in fluid communication with air entering said intake manifold, said second signal indicative of a pressure of air entering said intake manifold.

16. The system of claim 13 wherein said second sensor is a temperature sensor in fluid communication with air entering said intake manifold, said second signal indicative of a temperature of air entering said intake manifold.

17. The system of claim 13 wherein said second sensor is a mass flow sensor in fluid communication with said flow of exhaust gas from said exhaust manifold to said intake manifold, said second signal indicative of a mass flow rate of exhaust gas flowing from said exhaust manifold to said intake manifold.

18. The system of claim 13 wherein said second sensor is a pressure sensor in fluid communication with exhaust gas produced by the engine, said second signal indicative of a pressure of exhaust gas produced by the engine.

19. The system of claim 13 further including a turbocharger having a compressor in fluid communication with said intake manifold;

and wherein said second sensor is a mass air flow sensor in fluid communication with an air inlet to said compressor, said second signal indicative of a mass flow rate of air entering said compressor.

20. The system of claim 1 further including a turbocharger having a compressor in fluid communication with an intake manifold of the engine, and a turbine having a turbine inlet fluidly coupled to an exhaust manifold of the engine via a first exhaust conduit and a turbine outlet fluidly coupled to ambient via a second exhaust conduit;

and wherein the air handling mechanism is a flow control mechanism controlling either of an exhaust gas swallowing capacity and an exhaust gas swallowing efficiency of said turbine;

and wherein said first signal corresponds to a position of said flow control mechanism relative to a reference flow control mechanism position.

21. The system of claim 20 wherein said flow control mechanism is a geometry varying mechanism operable to vary an internal geometry, and therefore said exhaust gas swallowing capacity, of said turbine;

and wherein said first signal corresponds to a position of said actuator relative to a reference actuator position.

22. The system of claim 20 wherein said flow control mechanism is an exhaust throttle disposed in-line with either of said first and second exhaust conduits, said exhaust throttle operable to control a flow rate of exhaust gas through, and therefore said exhaust gas swallowing efficiency, of said turbine;

and wherein said first signal corresponds to a position of said exhaust throttle relative to a reference exhaust throttle position.

23. The system of claim 20 wherein said flow control mechanism is a wastegate valve having an inlet fluidly coupled to said first exhaust conduit and an outlet coupled to said second exhaust conduit, said wastegate valve operable to control an amount of exhaust gas supplied to, and therefore said exhaust gas swallowing efficiency of, said turbine;

and wherein said first signal corresponds to a position of said wastegate valve relative to a reference wastegate valve position.

24. The system of claim 20 wherein said second sensor is a speed sensor coupled to a turbocharger disposed in fluid communication with said intake and exhaust manifolds, said second signal indicative of rotational speed of said turbocharger.

25. The system of claim 20 wherein said second sensor is a pressure sensor in fluid communication with air entering said intake manifold, said second signal indicative of a pressure of air entering said intake manifold.

26. The system of claim 20 wherein said second sensor is a temperature sensor in fluid communication with air entering said intake manifold, said second signal indicative of a temperature of air entering said intake manifold.

27. The system of claim 20 further including a third exhaust conduit having an inlet fluidly coupled to said first exhaust conduit and an outlet fluidly coupled to said intake manifold;

and wherein said second sensor is a mass flow sensor in fluid communication with said third exhaust conduit, said second signal indicative of a mass flow rate of exhaust gas flowing from said first exhaust conduit to said intake manifold.

28. The system of claim 20 wherein said second sensor is a pressure sensor in fluid communication with said first exhaust conduit, said second signal indicative of a pressure of exhaust gas within said first exhaust conduit.

29. The system of claim 20 wherein said second sensor is a mass air flow sensor in fluid communication with an air inlet to said compressor, said second signal indicative of a mass flow rate of air entering said compressor.

30. A method of diagnosing an air handling mechanism of an air handling system for an internal combustion engine, the method comprising the steps of:

commanding an actuator of the air handling mechanism to a first position;

determining, after a predefined time period following the commanding step, a position of the air handling mechanism relative to a reference position;

determining, after the predefined time period following the commanding step, an operating condition of another component of the air handling system separate from, yet responsive to changes in the position of, the air handling mechanism; and

diagnosing the air handling mechanism as a function of the position of the air handling mechanism and the operating condition of the another component of the air handling system.

31. The method of claim 30 further including the steps of:

determining a pre-test engine operating condition; and

executing the commanding, determining and diagnosing steps only if the pre-test engine operating condition is within a predefined range.

32. The method of claim 31 wherein the pre-test engine operating condition is rotational speed of the engine.

33. The method of claim 31 wherein the pre-test engine operating condition is engine load.

34. The method of claim 30 wherein the diagnosing step includes determining that the air handling mechanism is operating normally if the position of the air handling mechanism is within a threshold value of the first position and the operation of the another component of the air handling system is within a range of expected operational values.

35. The method of claim 30 wherein the air handling mechanism includes a position sensor operable sense a position of the air handling mechanism relative to a reference position;

and wherein the diagnosing step includes determining an air handling mechanism position sensor fault if the position of the air handling mechanism is within a threshold value of the first position and the operation of the another component of the air handling system is not within a range of expected operational values.

36. The method of claim 35 further including the step of logging a fault code within memory corresponding to the air handling mechanism position sensor fault.

37. The method of claim 35 further including the step of activating at least one warning indicator upon detection of the air handling mechanism position sensor fault.

38. The method of claim 30 wherein the diagnosing step includes determining a fault associated with the air handling mechanism if the position of the air handling mechanism is not within a threshold value of the first position and the operation of the another component of the air handling system is within a range of expected operational values.

39. The method of claim 38 further including the step of logging a fault code within memory corresponding to the fault associated with the air handling mechanism.

40. The method of claim 38 further including the step of activating at least one warning indicator upon detection of the fault associated with the air handling mechanism.

41. The method of claim 30 wherein the diagnosing step includes determining a fault associated with the actuator if the position of the air handling mechanism is not within a threshold value of the first position and the operation of the another component of the air handling system is not within a range of expected operational values.

42. The method of claim 41 further including the step of logging a fault code within memory corresponding to the fault associated with the actuator.

43. The method of claim 41 further including the step of activating at least one warning indicator upon detection of the fault associated the said actuator.