Method for real-time estimation of engine combustion parameters from vibratory signals

• US 7,747,380 B2
• Filed: 03/07/2007
• Issued: 06/29/2010
• Est. Priority Date: 03/08/2006
• Status: Active Grant

• Current Assignee: IFP Energies Nouvelles
• Original Assignee: IFP Energies Nouvelles
• Inventors: Bentolina, Yohan, Grondin, Olivier, Chauvin, Jonathan
• Primary Examiner(s): Moulis; Thomas N
• Application Number:
  US12/281,798
• Publication Number:
  US 20090030593A1
• Time in Patent Office: 1,210 Days
• Field of Search: 123/406.24, 12340637-40639, 123/494, 731/140.7, 701/111, 701/115
• US Class Current: 701/111
• CPC Class Codes: G01M 15/12 by monitoring vibrations

Abstract

The invention relates to a method having application to combustion control of an internal-combustion engine for real-time estimation of engine combustion parameters from vibratory signals. A vibratory signal representative of the engine vibrations is continuously acquired as a function of the crank angle, from a vibration detector. Real-time filtering of this vibratory signal and real-time estimation of the Fourier decomposition coefficients for the acquired vibratory signal is carried out by inverting the dynamics of the filter which is used. Finally, real-time estimation of combustion parameters allowing the combustion to be qualified is carried out from these coefficients.

Claims

1. A method of determining combustion parameters of an internal-combustion engine including at least one vibration detector providing continuous acquisition as a function of the crank angle of a vibratory signal delivered by the detector and representative of vibrations of the engine, the vibratory signal including harmonics, and real-time filtering of the vibratory signal with a filter, the method comprising:

constructing a model of the dynamics of the filter and from the constructed model defining an adaptive non-linear estimator comprising a term related to the dynamics and a correction term;

estimating, in real time, Fourier decomposition coefficients for the vibratory signal acquired by the estimator;

determining, in real time, combustion parameters from the coefficients; and

determining energy of k harmonics of the vibratory signal using a sum of k squared Fourier decomposition coefficients; and

using the energy of the k harmonics to determine combustion parameters in real time.

2. A method as claimed in claim 1, wherein the Fourier decomposition coefficients are estimated for only harmonics correlated with the combustion.

3. A method as claimed in claim 2, wherein the harmonics correlated with the combustion are selected using spectral analysis.

4. A method as claimed in claim 2, wherein the harmonics correlated with the combustion are selected by using a time/frequency analysis.

5. A method as claimed in claim 2, wherein the harmonics correlated with the combustion are selected in the 300 Hz-3000 Hz frequency band.

6. A method as claimed in claim 1, wherein three harmonics are selected.

7. A method as claimed in claim 1, wherein an angular range including all of a combustion-related vibratory response is determined and the vibratory signal is limited to the angular range prior to carrying out the filtering.

8. A method as claimed in claim 1, wherein the filter is a band-pass filter.

9. A method as claimed in claim 1, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

10. A method as claimed in claim 1, wherein engine parameters are modified as a function of determination of combustion parameters for controlling combustion of the engine.

11. A method as claimed in claim 2, wherein three harmonics are selected.

12. A method as claimed in claim 3, wherein three harmonics are selected.

13. A method as claimed in claim 4, wherein three harmonics are selected.

14. A method as claimed in claim 5, wherein three harmonics are selected.

15. A method as claimed in claim 2, wherein an angular range including all of a combustion-related vibratory response is determined and the vibratory signal is limited to the angular range prior to carrying out the filtering.

16. A method as claimed in claim 3, wherein an angular range including all of a combustion-related vibratory response is determined and the vibratory signal is limited to the angular range prior to carrying out the filtering.

17. A method as claimed in claim 4, wherein an angular range including all of a combustion-related vibratory response is determined and the vibratory signal is limited to the angular range prior to carrying out the filtering.

18. A method as claimed in claim 5, wherein an angular range including all of a combustion-related vibratory response is determined and the vibratory signal is limited to the angular range prior to carrying out the filtering.

19. A method as claimed in claim 2, wherein the filter is a band-pass filter.

20. A method as claimed in claim 3, wherein the filter is a band-pass filter.

21. A method as claimed in claim 4, wherein the filter is a band-pass filter.

22. A method as claimed in claim 5, wherein the filter is a band-pass filter.

23. A method as claimed in claim 2, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

24. A method as claimed in claim 3, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

25. A method as claimed in claim 4, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

26. A method as claimed in claim 5, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

27. A method as claimed in claim 2, wherein engine parameters are modified as a function of determination of combustion parameters for controlling combustion of the engine.

28. A method as claimed in claim 3, wherein engine parameters are modified as a function of determination of combustion parameters for controlling combustion of the engine.

29. A method as claimed in claim 4, wherein engine parameters are modified as a function of determination of combustion parameters for controlling combustion of the engine.

30. A method as claimed in claim 5, wherein engine parameters are modified as a function of determination of combustion parameters for controlling combustion of the engine.

31. A method as claimed in claim 11, wherein an angular range including all of a combustion-related vibratory response is determined and the vibratory signal is limited to the angular range prior to carrying out the filtering.

32. A method as claimed in claim 11, wherein the filter is a band-pass filter.

33. A method as claimed in claim 15, wherein the filter is a band-pass filter.

34. A method as claimed in claim 11, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

35. A method as claimed in claim 15, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.

36. A method as claimed in claim 19, wherein the combustion parameters represent at least one of starting of combustion, maximizing of combustion, a duration of combustion and energy of combustion.