Adaptive ignition dwell based on ionization feedback

• US 7,318,411 B1
• Filed: 01/26/2007
• Issued: 01/15/2008
• Est. Priority Date: 01/26/2007
• Status: Expired due to Fees

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Zhu, Guoming G., Pursifull, Ross D.
• Primary Examiner(s): Kwon, John T.
• Application Number:
  US11/627,756
• Time in Patent Office: 354 Days
• Field of Search: 123/406.19, 12340626-40629, 123/406.37, 123/406.12, 123/406.14, 123/406.21, 123/406.22, 123/480, 701/111, 701/114
• US Class Current: 123/406.26
• CPC Class Codes: F02P 17/04 dynamically
• CPC Class Codes: F02P 17/12 Testing characteristics of the spark, ignition voltage or current testing of sparking plugs H01T13/60
• CPC Class Codes: F02P 2017/125 Measuring ionisation of combustion gas, e.g. by using ignition circuits
• CPC Class Codes: F02P 3/0456 using digital techniques
• CPC Class Codes: F02P 9/002 Control of spark intensity, intensifying, lengthening, suppression by means of current control in the storage devices F02P3/05, F02P3/09, during starting F02P15/12

Abstract

A system for determining a minimum ignition coil charge duration of an internal combustion engine to meet a desired level of combustion stability includes a sensor in communication with a controller. The sensor is configured to measure the ionization current of a cylinder of the internal combustion engine and output to the dwell controller. The controller is configured to determine a combustion stability criterion based upon the ionization signal and determine the minimum ignition coil charge duration based upon the combustion stability criterion.

Claims

1. A system for determining a minimum ignition coil charge duration of an internal combustion engine, the system comprising:

a sensor being configured to measure the ionization current of at least one cylinder of the internal combustion engine, the sensor being further configured to output an ionization signal based upon the ionization current of the at least one cylinder of the internal combustion engine; and

a stochastic controller in communication with the sensor, the controller being configured to determine a combustion stability criterion based upon the ionization signal and determine the minimum ignition coil charge duration based upon the combustion stability criterion.

2. The system of claim 1, wherein the stochastic controller includes an adaptive feedback loop for adjusting the minimum ignition coil charge duration in response to a change in the combustion stability criterion.

3. The system of claim 1, wherein the stochastic controller includes a regulation loop for adjusting the minimum ignition coil charge duration in response to a change in the combustion stability criterion.

4. The system of claim 1, wherein the stochastic controller includes an instant correction loop for calculating an instant correction signal based on an error signal.

5. The system of claim 1, wherein the controller includes a lookup table containing a plurality minimum ignition coil charge durations, each of the minimum ignition coil charge durations having a corresponding combustion stability criterion.

6. The system of claim 1, further comprising a signal conditioning module in communication with the sensor and the controller, the signal conditioning module being configured to condition the ionization signal.

7. The system of claim 1, further comprising an ignition control signal generator in communication with the controller, the ignition control signal generator being configured to receive the minimum ignition coil charge duration and adjust the duration of a spark applied by an ignition coil based on the minimum ignition coil charge duration.

8. The system of claim 1, wherein the controller is configured to the determine the combustion stability criterion by:

defining an integral ratio function;

determining an integration location of a given percentage based on the integral ratio function; and

determining the combustion stability criterion, wherein the combustion stability criterion is the standard deviation of the integration location.

9. The system of claim 8, wherein the integration ratio function is defined as:

10. The system of claim 9, wherein the integration location is defined as:

11. The system of claim 1, wherein the controller is configured to the control a minimal dwell duration using the ionization signal while the ignition coil charge duration of the internal combustion engine is trolled using a composite maximum brake torque criterion derived from the ionization current.

12. A method for determining a minimum ignition coil charge duration of an internal combustion engine, the method comprising the steps of:

measuring an ionization current of at least one cylinder of the internal combustion engine to determine an ionization signal;

determining a combustion stability criterion based upon the ionization signal; and

determining a minimum ignition coil charge duration based upon the combustion stability criterion.

13. The method of claim 12, further comprising the steps of:

measuring the ionization current of at least one cylinder of the internal combustion engine to determine the ionization signal;

determining if there has been a change in the combustion stability criterion;

determining the minimum ignition coil charge duration based upon the change in the combustion stability criterion.

14. The method of claim 12, further comprising the step of filtering the measured ionization current.

15. The method of claim 12, further comprising the step of transmitting the minimum ignition charge duration to an ignition control signal generator.

16. The method of claim 12, further comprising the step of adjusting the duration of a spark applied by an ignition coil based on the minimum ignition coil charge duration.

17. The method of claim 12, wherein the combustion stability criterion is determined by:

defining an integral ratio function;

determining an integration location of a given percentage based on the integral ratio function; and

determining the combustion stability criterion, wherein the combustion stability criterion is the standard deviation of the integration location.

18. The method of claim 17, wherein the integration ratio function is defined as:

19. The method of claim 18, wherein the integration location is defined as:

20. The method of claim 12, further comprising the step of controlling a minimal dwell duration using the ionization signal while the ignition coil charge duration of the internal combustion engine is trolled using a composite maximum brake torque criterion derived from the ionization current.