SYSTEMS AND METHODS FOR DIAGNOSING AN ENGINE

• US 20130068003A1
• Filed: 09/16/2011
• Published: 03/21/2013
• Est. Priority Date: 09/15/2011
• Status: Active Grant

• Current Assignee: GE Global Sourcing LLC (Westinghouse Air Brake Technologies Corporation)
• Original Assignee: General Electric Company
• Inventors: Ramachandrapanicker, Somakumar, Banerjee, Arijit, Mukherjee, Rupam, Kumar, AJITH, Flynn, Paul
• Granted Patent: US 8,626,372 B2
• Time in Patent Office: Days
• US Class Current: 73/114.25
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2030/206 related or induced by the engine
• CPC Class Codes: F02D 2041/288 for performing a transformation into the frequency domain, e.g. Fourier transformation
• CPC Class Codes: F02D 2200/1004 Estimation of the output torque
• CPC Class Codes: F02D 2200/1006 Engine torque losses, e.g. friction or pumping losses or losses caused by external loads of accessories
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 2200/1012 Engine speed gradient
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02D 29/06 peculiar to engines driving electric generators
• CPC Class Codes: F02D 41/0097 using means for generating speed signals
• CPC Class Codes: F02D 41/1498 measuring engine roughness
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

Methods and systems are provided for an engine. A condition of the engine may be diagnosed based on information provided by signals from speed sensors associated with the engine and/or other signals associated with a generator operationally connected to the engine. Different types of degradation may be distinguished based on discerning characteristics within the information. Thus, a degraded engine component may be identified in a manner that reduces service induced delay.

Claims

1. A method for a reciprocating engine, comprising:

diagnosing a condition of the engine based on harmonic content of a measured rotational speed of the reciprocating engine.

2. The method of claim 1, wherein at least one of a magnitude and a phase of a half-order frequency component of the harmonic content is analyzed to diagnose the condition.

3. The method of claim 1, wherein the reciprocating engine is first driven to a specified operating condition, state, or mode.

4. The method of claim 1, wherein the rotational speed is measured when the reciprocating engine reaches a determined operating condition, state, or mode.

5. A method for a reciprocating engine, comprising:

diagnosing a condition of the engine based on a difference in a measured rotational speed of the reciprocating engine from cycle to cycle.

6. The method of claim 5, wherein the reciprocating engine is first driven to a specified operating condition, state, or mode.

7. The method of claim 5, wherein the difference in a measured rotational speed is measured then the reciprocating engine reaches a determined operating condition, state, or mode.

8. A method for a reciprocating engine, comprising:

diagnosing a condition of the engine based on a difference in a time for the reciprocating engine to rotate over a determined angle from cycle to cycle.

9. The method of claim 8, wherein the reciprocating engine is first driven to a specified operating condition, state, or mode.

10. The method of claim 8, wherein the difference in a time is measured when the reciprocating engine reaches a determined operating condition, state, or mode.

11. A method for a reciprocating engine operationally connected to a generator, comprising:

measuring a rotational speed of the reciprocating engine over time;

measuring electrical parameters associated with the generator over time;

correlating characteristics of the measured rotational speed to characteristics of the measured electrical parameters; and

diagnosing a condition of the engine based on the correlated characteristics.

12. The method of claim 11, wherein characteristics of the measured rotational speed include at least one of harmonic content of the rotational speed, a difference in the measured rotational speed from cycle to cycle, and differences in a measured times for the reciprocating engine to rotate over a determined angle.

13. The method of claim 11, wherein the measured electrical parameters include at least one of an output current of the generator, an output voltage of the generator, a generator field current, a generator field voltage, a dc-link current, and a dc-link voltage.

14. The method of claim 11, wherein the reciprocating engine is first driven to a specified operating condition, state, or mode.

15. The method of claim 11, wherein the measuring and the correlating are performed when the reciprocating engine reaches a determined operating condition, state, or mode.

16. A method for a reciprocating engine, comprising:

measuring a rotational speed of the reciprocating engine over time;

determining a torque profile by combining acceleration components derived from the measured rotational speed at determined characteristic frequencies; and

diagnosing a condition of the engine based on characteristics of the torque profile.

17. The method of claim 16, wherein the reciprocating engine is first driven to a specified operating condition, state, or mode.

18. The method of claim 16, wherein the measuring and determining are performed when the reciprocating engine reaches a determined operating condition, state, or mode.

19. A vehicle system, comprising:

an engine;

a sensor for measuring a rotational speed of the reciprocating engine over time; and

a controller including instructions configured to sample the measured speed and diagnose a condition of the engine based on at least one of;

harmonic content of the measured speed;

a difference in the measured speed from cycle to cycle; and

differences in times for the engine to rotate over a determined angle.

20. The vehicle system of claim 19, wherein the controller is operable to report a degraded engine condition.

21. The vehicle system of claim 19, wherein the controller further includes instructions configured to adjust an engine operating parameter based on the diagnosed condition.

22. A vehicle system, comprising:

an engine;

a generator operatively connected to the engine;

a sensor for measuring a rotational speed of the reciprocating engine over time;

sensors for measuring electrical parameters associated with the generator during operation; and

a controller including instructions configured to sample the measured speed and the measured electrical parameters and diagnose a condition of the engine based on correlations between characteristics of the measured speed and characteristics of electrical parameters of the generator.

23. The vehicle system of claim 22, wherein the controller is operable to report a degraded engine condition.

24. The vehicle system of claim 22, wherein the controller further includes instructions configured to adjust an engine operating parameter based on the diagnosed condition.

25. A test kit, comprising a controller that is operable to determine a condition of a reciprocating engine based on at least one characteristic of a measured rotational speed of the reciprocating engine over time.

26. The test kit of claim 25, further comprising one or more sensors to sense electrical parameters associated with a generator that is operationally connected to the engine during operation, wherein the controller is operable to communicate with the one or more sensors to sample the electrical parameters over time, and wherein the controller is further operable to correlate characteristics of the measured rotational speed and characteristics of the electrical parameters to diagnose a condition of the engine.

27. A method for a reciprocating engine, comprising:

measuring a plurality of time intervals, wherein each time interval corresponds to an amount of time it takes for an engine to rotate over a specified angle;

determining a frequency content of the plurality of time intervals;

calculating a combined value of the amplitudes of the frequency content around a specified harmonic frequency; and

diagnosing a condition of the engine based on the combined value.

28. The method of claim 27, wherein the specified harmonic frequency is a half-order frequency.

29. The method of claim 27, wherein the combined value is a root-mean-square (RMS) value.