Methods and apparatus for performing combustion analysis in an internal combustion engine utilizing ignition voltage analysis

• US 5,687,082 A
• Filed: 08/22/1995
• Issued: 11/11/1997
• Est. Priority Date: 08/22/1995
• Status: Expired due to Fees

• Current Assignee: Ohio State University
• Original Assignee: Ohio State University
• Inventors: Rizzoni, Giorgio
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US08/517,544
• Time in Patent Office: 812 Days
• Field of Search: 364/431.03, 364/431.04, 364/431.08, 364/483, 364/487, 364/554, 364/571.01, 364/431.054, 123/406, 123/419, 395/3, 395/20, 395/21, 395/23, 73/117.3, 73/116, 73/118.1, 73/118.2, 73/117.1, 324/378, 324/379, 324/396, 324/399
• US Class Current: 701/111
• CPC Class Codes: F02D 41/1405 Neural network control
• CPC Class Codes: F02P 17/12 Testing characteristics of the spark, ignition voltage or current testing of sparking plugs H01T13/60

Abstract

An ignition voltage analysis is performed to provide a combustion diagnosis. A first set of characteristic parameters are provided relating a plurality of spark plug voltage, current or gap impedance waveform signals to a plurality of combustion quality measures. A spark plug voltage, current or gap impedance waveform signal is sampled in real time during a first combustion process. A second set of characteristic parameters are then generated based upon the sampled first spark plug voltage waveform signal. The combustion process is classified as a one of a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event, and a misfire event. The spark plug voltage, current or gap impedance waveform signals are classified according to a statistical closeness to parameters generated by a testing engine operated in each of the above operating modes. The sampled ignition voltage signals are correlated with combustion performance indices for use in practical in-vehicle implementation for feedback control, engine monitoring, or the like.

Claims

1. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of spark plug voltage waveform signals with a plurality of combustion quality measures including operating a first internal combustion engine under a plurality of combustion conditions while sampling a spark plug voltage waveform to obtain at least one of a knocking combustion measure, a normal combustion measure, a slow burn combustion measure, a partial burn combustion measure, and a misfire combustion measure;

sampling a first spark plug voltage waveform signal during a first combustion process in a second internal combustion engine;

generating a second set of characteristic parameters based on said first spark plug voltage waveform signal; and

,

classifying said first combustion process as one of said plurality of combustion quality measures based on a correlation between said first set of characteristic parameters and said second set of characteristic parameters.

2. The method according to claim 1 wherein:

the step of classifying includes classifying said first combustion process as one of said plurality of combustion quality measures based on a statistical closeness between said first set of characteristic parameters and said second set of characteristic parameters.

3. The method according to claim 1 wherein:

the step of generating said second set of characteristic parameters includes performing at least one of;

a principal component analysis on said first spark plug voltage waveform signal, a wavelet transformation analysis on said first spark voltage waveform signal, a linear parametric system identification analysis on said first spark plug voltage signal, a non-linear parametric system identification analysis on said first spark plug voltage waveform signal, a neural network processing analysis on said first spark plug voltage waveform signal, and a fuzzy classification analysis on said first spark plug voltage waveform signal.

4. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of spark plug voltage waveform signals with at least one of a knocking combustion measure, a normal combustion measure, a slow burn combustion measure, a partial burn combustion measure, and a misfire combustion measure;

sampling a first spark plug voltage waveform signal during a first combustion process;

generating a second set of characteristic parameters based on said first spark plug voltage waveform signal by performing at least one of;

a principal component analysis on said first spark plug voltage waveform signal, a wavelet transformation analysis on said first spark plug voltage waveform signal, a linear parametric system identification analysis on said first spark plug voltage signal, a non-linear parametric system identification analysis on said first spark plug voltage waveform signal, a neural network processing analysis on said first spark plug voltage waveform signal, and a fuzzy classification analysis on said first spark plug voltage waveform signal; and

,

classifying said first combustion process as one of said combustion quality measures based on a correlation between said first set of characteristic parameters and said second set of characteristic parameters.

5. The method according to claim 4 wherein:

the step of providing said first set of characteristic parameters includes;

deriving N principal components of said plurality of spark plug voltage waveform signals; and

,

defining an area in an N dimensional observation space, said area corresponding to said combustion measures; and

,

the step of classifying includes;

deriving N principal components of said first spark plug voltage waveform signal to define a position in said N dimensional observation space; and

,

identifying said first combustion process as said combustion measure based on said position in said N dimensional observation space with respect to said plurality of areas.

6. The method according to claim 5 wherein:

the step of providing said first set of characteristic parameters includes operating a first internal combustion engine under a plurality of combustion conditions including a plurality of;

a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event and a misfire event while sampling said plurality of spark plug voltage waveform signals; and

,

the step of sampling said first spark plug voltage waveform signal includes sampling a spark plug voltage waveform signal in a second internal combustion engine.

7. The method according to claim 4 wherein:

the step of providing said first set of characteristic parameters includes decomposing said plurality of spark plug voltage waveform signals into a first plurality of orthogonal basis functions, each of said plurality of orthogonal basis functions having associated wavelet coefficients corresponding to said combustion measure; and

,

the step of classifying includes;

decomposing said first spark plug voltage waveform signal into a first basis function having a first wavelet coefficient; and

,

identifying said first combustion process as said combustion measure based upon a correspondence between said first wavelet coefficient and the wavelet coefficients associated with said plurality of orthogonal basis functions.

8. The method according to claim 7 wherein:

the step of providing said first set of characteristic parameters includes operating a first internal combustion engine under a plurality of combustion conditions including a plurality of;

a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event and a misfire event while sampling said plurality of spark plug voltage waveform signals; and

,

the step of sampling said first spark plug voltage waveform signal includes sampling a spark plug voltage waveform signal in a second internal combustion engine.

9. The method according to claim 4 wherein:

the step of providing said first set of characteristic parameters includes developing a first set of linear coefficients for mapping a white noise signal into said plurality of spark plug voltage waveform signals, the first set of linear filter coefficients assuming a unique state for said combustion measure; and

,

the step of classifying includes;

developing a second set of linear filter coefficients for mapping a white noise signal into said first spark plug voltage waveform signal; and

,

identifying said first combustion process as said combustion measure based upon a correspondence between said first set of filter coefficients and said second set of filter coefficients.

10. The method according to claim 9 wherein:

the step of developing said first set of linear filter coefficients includes operating a first internal combustion engine under a plurality of combustion conditions including a plurality of;

a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event and a misfire event while sampling said plurality of spark plug voltage waveform signals; and

,

the step of sampling said first spark plug voltage waveform signals includes sampling a spark voltage waveform signal in a second internal combustion engine.

11. The method according to claim 4 wherein:

the step of providing said first set of characteristic parameters includes developing a first set of non-linear coefficients for mapping a white noise signal into said plurality of spark plug voltage waveform signals, the first set of non-linear filter coefficients assuming a unique state for said combustion measure; and

,

the step of classifying includes;

developing a second set of non-linear filter coefficients for mapping a white noise signal into said first plug spark voltage waveform signal; and

,

identifying said first combustion process as said combustion measure based upon a correspondence between said first set of filter coefficients and said second set of filter coefficients.

12. The method according to claim 11 wherein:

the step of developing said first set of non-linear filter coefficients includes operating a first internal combustion engine under a plurality of combustion conditions including a plurality of;

a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event and a misfire event while sampling said plurality of spark plug voltage waveform signals; and

,

the step of sampling said first spark plug voltage waveform signals includes sampling a spark plug voltage waveform signal in a second internal combustion engine.

13. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of spark plug current waveform signals with a plurality of combustion quality measures including operating a first internal combustion engine under a plurality of combustion conditions to obtain at least one of a knocking combustion measure, a normal combustion measure, a slow burn combustion measure, a partial burn combustion measure, and a misfire combustion measure;

sampling a first spark plug current waveform signal during a first combustion process of a second internal combustion engine;

generating a second set of characteristic parameters based on said first spark plug current waveform signal; and

,

classifying said first combustion process as one of said combustion quality measures based on a correlation between said first set of characteristic parameters and said second set of characteristic parameters.

14. The method according to claim 13 wherein;

the step of classifying includes classifying said first combustion process as one of said combustion quality measures based on a statistical closeness between said first set of characteristic parameters and said second set of characteristic parameters.

15. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of spark plug current waveform signals with a combustion quality measure including operating a first internal combustion engine under a plurality of combustion conditions including a plurality of;

a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event and a misfire event while sampling said plurality of spark plug current waveform signals;

sampling a first spark plug current waveform signal during a first combustion process including sampling a spark plug current waveform signal in a second internal combustion engine;

generating a second set of characteristic parameters based on said first spark plug current waveform signal; and

classifying said first combustion process as one of said combustion quality measures based on a correlation between said first set of characteristic parameters and said second set of characteristic parameters.

16. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of spark plug gap impedance waveform signals with a plurality of combustion quality measures including operating a first internal combustion engine under a plurality of combustion conditions to obtain at least one of a knocking combustion measure, a normal combustion measure, a slow burn combustion measure, a partial burn combustion measure, and a misfire combustion measure;

sampling a first spark plug gap impedance waveform signal during a first combustion process of a second internal combustion engine;

generating a second set of characteristic parameters based on said first spark plug gap impedance waveform signal; and

,

classifying said first combustion process as one of said combustion quality measures based on a correlation between said first set of characteristic parameters and said second set of characteristic parameters.

17. The method according to claim 16 wherein:

the step of classifying includes classifying said first combustion process as one of said combustion quality measures based on a statistical closeness between said first set of characteristic parameters and said second set of characteristic parameters.

18. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of spark plug gap impedance waveform signals with a combustion quality measure including operating a first internal combustion engine under a plurality of combustion conditions including a plurality of;

a knocking combustion event, a normal combustion event, a slow burn event, a partial burn event and a misfire event while sampling said plurality of spark plug gap impedance waveform signals;

sampling a first spark plug gap impedance waveform signal during a first combustion process including sampling a spark plug gap impedance waveform signal in a second internal combustion engine;

generating a second set of characteristic parameters based on said first spark plug gap impedance waveform signal; and

,

classifying said first combustion process as one of said combustion quality measures based on a correlation between said first set of characteristic parameters and said second set of characteristic parameters.

19. A method of combustion analysis in an internal combustion engine comprising:

providing a first set of characteristic parameters relating a plurality of signature spark plug electrical waveform signals with a plurality of different known combustion quality measures for an internal combustion engine of a particular type;

storing said first set of signature characteristic parameters of said particular type of internal combustion engine in a memory of an onboard computer of a vehicle, said vehicle further comprising an internal combustion engine of said particular type;

sampling a real time spark plug electrical waveform signal of said particular type of engine of said vehicle during a real time combustion process;

generating a second set of characteristic parameters based upon said real time spark plug electrical waveform signal; and

comparing said first and second sets of characteristic parameters to classify said real time combustion process of said vehicle engine as one of said known combustion quality measures.

20. The method as set forth in claim 19, wherein said known combustion quality measures include at least one of:

a normal combustion measure;

a knocking combustion measure;

a slow burn combustion measure;

a partial burn combustion measure; and

,

a misfire combustion measure.

21. The method as set forth in claim 19, wherein the step of generating a second set of characteristic parameters based upon said real time spark plug electrical waveform signal includes performing at least one of:

a principal component analysis on said real time spark plug electrical waveform signal;

a wavelet transformation analysis on said real time spark plug electrical waveform signal;

a linear parametric system identification analysis on said real time spark plug electrical waveform signal;

a non-linear parametric system identification analysis on said real time spark plug electrical waveform signal;

a neural network processing analysis on said real time spark plug electrical waveform signal; and

,

a fuzzy classification analysis on said real time spark plug electrical waveform signal.