System and method for diagnosing and calibrating internal combustion engines

• US 20030216853A1
• Filed: 05/15/2002
• Published: 11/20/2003
• Est. Priority Date: 05/15/2002
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Jacobson, Evan Earl
• Granted Patent: US 6,935,313 B2
• Time in Patent Office: Days
• US Class Current: 701/106
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 41/1405 Neural network control
• CPC Class Codes: F02D 41/2496 the memory being part of a closed loop

Abstract

A method, system, and machine-readable storage medium for determining a predetermined operating condition of an internal combustion engine are disclosed. In operation, the method, system and machine-readable storage medium measure a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle. Next, the method, system, and machine-readable storage medium determine at least a first value for an operating parameter of the engine using the measured cylinder pressure, determine a second value for the operating parameter of the engine using data received from at least one engine sensor, and then generate a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

Claims

1. A method for determining a predetermined operating condition of an internal combustion engine, the method comprising:

measuring a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle;

determining at least a first value for an operating parameter of the engine using the measured cylinder pressure;

determining a second value for the operating parameter of the engine using data received from at least one engine sensor; and

generating a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

2. The method of claim 1, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

3. The method of claim 1, wherein the generating step includes the step of generating a predetermined signal if a difference between the first value and the second value exceeds a predetermined amount.

4. The method of claim 1, further comprising controlling operation of the air-fuel ratio in response to the first value, if the difference is less than substantially +/−

5%.

5. The method of claim 1, further comprising controlling at least one of intake valve activation, exhaust valve activation, and turbocharger operation.

6. The method of claim 1, wherein the operating parameter comprises torque.

7. The method of claim 1, wherein the at least one stroke comprises a compression stroke.

8. The method of claim 7, wherein the operating parameter comprises a mass of air present in a cylinder.

9. The method of claim 1, wherein the at least one stroke comprises a power stroke.

10. The method of claim 9, wherein the operating parameter comprises a heat release profile of at least one combustion chamber.

11. The method of claim 1, wherein the at least one stroke comprises an overlap of the exhaust stroke and intake stroke.

12. The method of claim 7, wherein the operating parameter comprises a residual gas measurement from at least one combustion chamber.

13. A method for determining a predetermined operating condition of an internal combustion engine, the method comprising:

storing in memory data corresponding to a volumetric efficiency table;

determining a first assessed air mass value using data received from at least one hardware sensor and the volumetric efficiency table;

measuring a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle;

determining at least a first value for an operating parameter of the engine using the measured cylinder pressure;

determining a second value for the operating parameter of the engine using data received from at least one engine sensor; and

generating a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

14. The method of claim 13, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

15. The method of claim 13, wherein the generating step further comprises generating a predetermined signal if a difference between the first value and the second value exceeds a predetermined amount.

16. A method for determining a predetermined operating condition of an internal combustion engine, the method comprising:

measuring a cylinder pressure in at least one combustion chamber, for at least one cylinder, at a predetermined point in a combustion cycle;

inputting the measured cylinder pressure for the at least one cylinder into a neural network;

determining from the neural network output, whether a predetermined condition exists in at least one cylinder; and

adjusting a component of the at least one cylinder, if an abnormal condition has been detected.

17. The method of claim 16, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

18. The method of claim 16, wherein the adjusted component is valve timing.

19. The method of claim 16, wherein the adjusted component comprises an air-fuel ratio.

20. The method of claim 16, wherein the neural network comprises a back propagation neural network.

21. The method of claim 16, wherein the abnormal condition comprises a cylinder misfire.

22. The method of claim 21, wherein the determining step further comprises:

evaluating at least two pressure outputs from a cylinder;

comparing the output to a previous output pressure from the cylinder; and

determining that the cylinder has misfired, if;

the difference between the current output value and a previous output value has a predetermined relationship; and

the engine has remained in a substantially constant operating condition.

23. The method of claim 22, wherein the determining step includes the step of determining that the cylinder has misfired, if the difference between the current output value and a previous output value exceeds a predetermined amount.

24. The method of claim 16, wherein the abnormal condition comprises a combustion knock.

25. The method of claim 24, wherein the determining step further includes:

evaluating a peak rate of pressure rise from a cylinder; and

determining that a combustion knock has occurred, if the peak rate of pressure rise exceeds a predetermined value.

26. The method of claim 25, wherein the determining step further comprises determining that a combustion knock has occurred, if the difference between a current pressure output value and a previous pressure output value exceeds a predetermined amount.

27. A machine-readable storage medium having stored thereon machine executable instructions, the execution of said instructions adapted to implement a method for determining a predetermined operating condition of an internal combustion engine, the method comprising:

measuring a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle;

determining at least a first value for an operating parameter of the engine using the measured cylinder pressure;

determining a second value for the operating parameter of the engine using data received from at least one engine sensor; and

generating a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

28. The machine-readable storage medium of claim 27, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

29. The machine-readable storage medium of claim 27, wherein the generating step includes the step of generating a predetermined signal if a difference between the first value and the second value exceeds a predetermined amount.

30. The machine-readable storage medium of claim 27, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

31. The machine-readable storage medium of claim 27, further including controlling operation of the air-fuel ratio in response to the first value, if the difference is less than substantially +/−

5%.

32. The machine-readable storage medium of claim 27, further including controlling at least one of intake valve activation, exhaust valve activation, and turbocharger operation.

33. The machine-readable storage medium of claim 27, wherein the operating parameter is torque.

34. The machine-readable storage medium of claim 27, wherein the at least one stroke comprises a compression stroke.

35. The machine-readable storage medium of claim 34, wherein the operating parameter comprises a mass of air present in a cylinder.

36. The machine-readable storage medium of claim 27, wherein the at least one stroke comprises a power stroke.

37. The machine-readable storage medium of claim 36, wherein the operating parameter comprises a heat release profile of at least one combustion chamber.

38. The machine-readable storage medium of claim 27, wherein the at least one stroke is an overlap of the exhaust stroke and intake stroke.

39. The machine-readable storage medium of claim 36, wherein the operating parameter comprises a residual gas measurement from at least one combustion chamber.

40. A machine-readable storage medium having stored thereon machine executable instructions, the execution of said instructions adapted to implement a method for determining a predetermined operating condition of an internal combustion engine, the method comprising:

storing in memory data corresponding to a volumetric efficiency table;

determining a first assessed air mass value using data received from at least one hardware sensor and the volumetric efficiency table;

measuring a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle;

determining at least a first value for an operating parameter of the engine using the measured cylinder pressure;

determining a second value for the operating parameter of the engine using data received from at least one engine sensor; and

generating a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

41. The machine-readable storage medium of claim 40, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

42. The machine-readable storage medium of claim 40, wherein the generating step further comprises generating a predetermined signal if a difference between the first value and the second value exceeds a predetermined amount.

43. A machine-readable storage medium having stored thereon machine executable instructions, the execution of said instructions adapted to implement a method for determining a predetermined operating condition of an internal combustion engine, the method comprising:

measuring a cylinder pressure in at least one combustion chamber, for at least one cylinder, at a predetermined point in a combustion cycle;

inputting the measured cylinder pressure for the at least one cylinder into a neural network;

determining from the neural network output, whether a predetermined condition exists in at least one cylinder; and

adjusting a component of the at least one cylinder, if an abnormal condition has been detected.

44. The machine-readable storage medium of claim 43, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

45. The machine-readable storage medium of claim 43, wherein the adjusted component is valve timing.

46. The machine-readable storage medium of claim 43, wherein the adjusted component comprises an air-fuel ratio.

47. The machine-readable storage medium of claim 43, wherein the neural network comprises a back propagation neural network.

48. The machine-readable storage medium of claim 43, wherein the abnormal condition comprises a cylinder misfire.

49. The machine-readable storage medium of claim 48, wherein the determining step further includes;

evaluating a pressure output from a cylinder;

comparing the output to a previous output pressure from the cylinder; and

determining that the cylinder has misfired, if;

the difference between the current output value and a previous output value has a predetermined relationship; and

the engine has remained in a substantially constant operating condition.

50. The machine-readable storage medium of claim 43, wherein the abnormal condition comprises a combustion knock.

51. The machine-readable storage medium of claim 50, wherein the determining step further includes:

evaluating a peak rate of pressure rise from a cylinder; and

determining that a combustion knock has occurred, if the peak rate of pressure rise exceeds a predetermined amount.

52. An apparatus for determining a predetermined operating condition of an internal combustion engine, the apparatus comprising:

a module configured to measure a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle;

a module configured to determine at least a first value for an operating parameter of the engine using the measured cylinder pressure;

a module configured to determine a second value for the operating parameter of the engine using data received from at least one engine sensor; and

a module configured to generate a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

53. The apparatus of claim 52, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

54. The apparatus of claim 52, wherein the module configured to generate a predetermined signal includes a module configured to generate a predetermined signal if a difference between the first value and the second value exceeds a predetermined amount.

55. The apparatus of claim 52, further including a module configured to control operation of the air-fuel ratio in response to the first value, if the difference is less than substantially +/−

5%.

56. The apparatus of claim 52, further including a module adapted to control at least one of intake valve activation, exhaust valve activation, and turbocharger operation.

57. The apparatus of claim 56, wherein the plurality of modules comprise functionally related computer program code and data.

58. The apparatus of claim 52, wherein the operating parameter is torque.

59. The apparatus of claim 52, wherein the at least one stroke comprises a compression stroke.

60. The apparatus of claim 59, wherein the operating parameter comprises a mass of air present in a cylinder.

61. The apparatus of claim 52, wherein the at least one stroke comprises a power stroke.

62. The apparatus of claim 61, wherein the operating parameter comprises a heat release profile of at least one combustion chamber.

63. The apparatus of claim 52, wherein the at least one stroke comprises an overlap of the exhaust stroke and intake stroke.

64. The apparatus of claim 61, wherein the operating parameter comprises a residual gas measurement from at least one combustion chamber.

65. An apparatus for determining a predetermined operating condition of an internal combustion engine, the apparatus comprising:

storing in memory data corresponding to a volumetric efficiency table;

a module configured to determine a first assessed air mass value using data received from at least one hardware sensor and the volumetric efficiency table;

a module configured to measure a cylinder pressure in at least one combustion chamber at a predetermined point in a combustion cycle;

a module configured to determine at least a first value for an operating parameter of the engine using the measured cylinder pressure;

a module configured to determine a second value for the operating parameter of the engine using data received from at least one engine sensor; and

a module configured to generate a predetermined signal if a difference between the first value and the second value has a predetermined relationship.

66. The apparatus of claim 65, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

67. The apparatus of claim 65, wherein the module configured to generate further comprises a module configured to generate a predetermined signal if a difference between the first value and the second value exceeds a predetermined amount.

68. The apparatus of claim 65, wherein the plurality of modules comprise functionally related computer program code and data.

69. An apparatus for determining a predetermined operating condition of an internal combustion engine, the apparatus comprising:

a module configured to measure a cylinder pressure in at least one combustion chamber, for at least one cylinder, at a predetermined point in a combustion cycle;

a module configured to input the measured cylinder pressure for the at least one cylinder into a neural network;

a module configured to determine from the neural network output, whether a predetermined condition exists in at least one cylinder; and

a module configured to adjust a component of the at least one cylinder, if an abnormal condition has been detected.

70. The apparatus of claim 69, wherein the predetermined point in a combustion cycle is during at least one stroke of a combustion cycle.

71. The apparatus of claim 69, wherein the adjusted component is valve timing.

72. The apparatus of claim 69, wherein the adjusted component comprises air-fuel ratio.

73. The apparatus of claim 69, wherein the neural network comprises a back propagation neural network.

74. The apparatus of claim 69, wherein the abnormal condition comprises a cylinder misfire.

75. The apparatus of claim 74, wherein the module configured to determine further includes;

a module configured to evaluate a pressure output from a cylinder;

a module configured to compare the output to a previous output pressure from the cylinder; and

a module configured to determine that the cylinder has misfired, if;

the difference between the current output value and a previous output value has a predetermined relationship; and

the engine has remained in a substantially constant operating condition.

76. The apparatus of claim 69, wherein the abnormal condition comprises a combustion knock.

77. The apparatus of claim 76, wherein the module configured to determine further includes:

a module configured to evaluate a pressure output from a cylinder; and

a module configured to determine that a combustion knock has occurred, if a peak rate of pressure rise exceeds a predetermined amount.

78. The apparatus of claim 77, wherein the plurality of modules comprise functionally related computer program code and data.