Abnormal combustion detection method for internal-combustion engines from several combustion indicators

• US 8,359,909 B2
• Filed: 11/02/2010
• Issued: 01/29/2013
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: IFP Energies Nouvelles
• Original Assignee: IFP Energies Nouvelles
• Inventors: Duval, Laurent, Pagot, Alexandre, Thirouard, Benoist, Zaccardi, Jean-Marc
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US12/917,650
• Publication Number:
  US 20110113869A1
• Time in Patent Office: 819 Days
• Field of Search: 731/140.2, 731/140.7, 731/141.6
• US Class Current: 73/114.16
• CPC Class Codes: F02D 19/12 peculiar to engines working with non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel
• CPC Class Codes: F02D 2041/286 comprising means for signal processing
• CPC Class Codes: F02D 35/023 by determining the cylinder pressure
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02D 35/028 by determining the combustion timing or phasing
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/0025 Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
• CPC Class Codes: F02D 41/402 Multiple injections
• CPC Class Codes: G01M 15/08 by monitoring pressure in cylinders

Abstract

An abnormal combustion detection method is disclosed for spark-ignition internal-combustion engines, from combustion indicators. Combustion indicators, such as CA10 and MIP, are determined which are converted to new indicators having lower dispersions than those of indicators for normal combustions that are not converted. A parameter characterizing a distribution of N values of the new combustion indicators, acquired over N cycles preceding the cycle in progress, is then determined. The start of an abnormal combustion is thereafter detected by comparing this parameter with a threshold, and the course of the abnormal combustion detected in the combustion chamber is controlled.

Claims

1. A method for controlling the combustion of a spark-ignition internal-combustion engine for each engine cycle wherein an abnormal combustion is detected in a combustion chamber of at least one cylinder of the engine and a signal representative of a state of the combustion during individual cycles is recorded by a detector in the engine, comprising:

obtaining combustion indicators from the signal;

converting the indicators to at least one new indicator, for which a distribution of N values acquired over N cycles preceding a cycle in progress has, for normal combustions, a lower dispersion than that of indicators which are not converted;

detecting a start of an abnormal combustion during at least one cycle by comparing the at least one new indicator with a previously determined threshold; and

controlling a course of the abnormal combustion which is detected in the combustion chamber during cycles in which the abnormal combustion is detected.

2. A method as claimed in claim 1, wherein the indicators are converted by a linear regression wherein the at least one new indicator corresponds to a difference between a real value of indicators which are not converted and an indicator value estimated by the linear regression.

3. A method as claimed in claim 2, wherein the threshold is defined from at least one parameter which characterizes the distribution of N values of the at least one new indicator.

4. A method as claimed in claim 3, wherein the signal is a continuous pressure measurement within the at least one cylinder.

5. A method as claimed in claim 4, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

6. A method as claimed in claim 3, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

7. A method as claimed in claim 2, wherein the signal is a continuous pressure measurement within the at least one cylinder.

8. A method as claimed in claim 7, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

9. A method as claimed in claim 2, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

10. A method as claimed in claim 2, wherein the indicators are converted by determining a new indicator providing information regarding variability of the indicators which are not converted.

11. A method as claimed in claim 1, wherein the indicators are converted by a principal component analysis wherein the at least one new indicator corresponds to the principal components of the principal component analysis.

12. A method as claimed in claim 11, wherein the threshold is defined from at least one parameter which characterizes the distribution of N values of the at least one new indicator.

13. A method as claimed in claim 12, wherein the signal is a continuous pressure measurement within the at least one cylinder.

14. A method as claimed in claim 13, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

15. A method as claimed in claim 12, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

16. A method as claimed in claim 11, wherein the signal is a continuous pressure measurement within the at least one cylinder.

17. A method as claimed in claim 16, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

18. A method as claimed in claim 11, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

19. A method as claimed in claim 11, wherein the indicators are converted by determining a new indicator providing information regarding variability of the indicators which are not converted.

20. A method as claimed in claim 1, wherein the threshold is defined from at least one parameter which characterizes the distribution of N values of the at least one new indicator.

21. A method as claimed in claim 20, wherein the signal is a continuous pressure measurement within the at least one cylinder.

22. A method as claimed in claim 21, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

23. A method as claimed in claim 20, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

24. A method as claimed in claim 20, wherein the indicators are converted by determining a new indicator providing information regarding variability of the indicators which are not converted.

25. A method as claimed in claim 20, wherein the at least one parameter is determined by disregarding values among the N values.

26. A method as claimed in claim 1, wherein the signal is a continuous pressure measurement within the at least one cylinder.

27. A method as claimed in claim 26, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

28. A method as claimed in claim 1, wherein the at least one new indicator is a crank angle at which 10% of energy introduced in the at least one cylinder has been released.

29. A method as claimed in claim 28, wherein the indicators are converted by determining a new indicator providing information regarding variability of the indicators which are not converted.

30. A method as claimed in claim 1, wherein the indicators are converted by determining a new indicator providing information regarding variability of the indicators which are not converted.