ENGINE WITH LASER IGNITION

• US 20160040644A1
• Filed: 10/22/2015
• Published: 02/11/2016
• Est. Priority Date: 11/15/2012
• Status: Abandoned Application

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Martin, Douglas Raymond, Miller, Kenneth James
• Application Number:
  US14/920,694
• Publication Number:
  US 20160040644A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02D 2200/1015 Engines misfires
• CPC Class Codes: F02D 35/022 using an optical sensor, e.g. in-cylinder light probe
• CPC Class Codes: F02D 35/025 by determining temperatures inside the cylinder, e.g. combustion temperatures
• CPC Class Codes: F02D 35/026 using an estimation
• CPC Class Codes: F02D 35/027 using knock sensors
• CPC Class Codes: F02P 17/02 Checking or adjusting ignition timing
• CPC Class Codes: F02P 23/04 Other physical ignition means, e.g. using laser rays
• CPC Class Codes: F02P 5/045 combined with electronic control of other engine functions, e.g. fuel injection in general F02D37/02
• CPC Class Codes: F02P 5/152 dependent on pinking detecting or indicating knocks in internal-combustion engines G01L23/22
• CPC Class Codes: F02P 5/1527 with means allowing burning of two or more fuels, e.g. super or normal, premium or regular
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Systems and methods for increasing an accuracy of misfire detection are described. An infra-red sensor coupled to a cylinder is used to sense an in-cylinder temperature profile following a laser ignition event. A misfire event is identified based on a deviation of the sensed profile from an expected profile.

Claims

1. A method, comprising:

operating a laser ignition device of an engine cylinder to ignite an air-fuel mixture in the cylinder;

generating a cylinder temperature profile over a combustion event of the cylinder via an infra-red sensor; and

indicating a cylinder misfire event based on the generated cylinder temperature profile.

2. The method of claim 1, wherein indicating a misfire based on an infra-red sensor includes indicating a misfire based on a cylinder temperature profile following the laser ignition of the air-fuel mixture and in the same cycle as the laser ignition, the cylinder temperature profile estimated by the infra-red sensor.

3. The method of claim 2, wherein the indicating includes indicating a misfire if a peak temperature of the cylinder temperature profile occurs outside a threshold duration since the operating of the laser ignition device.

4. The method of claim 2, wherein the indicating includes indicating a misfire in response to a peak in-cylinder temperature of the cylinder temperature profile being lower than a threshold temperature.

5. The method of claim 1, wherein indicating a misfire includes indicating that the misfire was generated by the laser ignition of the air-fuel mixture.

6. The method of claim 1, further comprising, in response to occurrence of a threshold number of cylinder misfire events, setting a diagnostic code and performing a mitigating action including one or more of operating the cylinder richer than stoichiometry, limiting engine airflow, reducing an amount of EGR, and increasing a laser ignition power level.

7. The method of claim 1, wherein the indicating is during a first cylinder combustion event, the method further comprising, adjusting a timing of igniting air-fuel mixture with the laser ignition device during a second, subsequent cylinder combustion event based on the indication of misfire.

8. The method of claim 7, wherein the adjusting includes advancing or retarding the timing towards MBT.

9. The method of claim 1, wherein the indicating is during a first cylinder combustion event, the method further comprising, adjusting fuel injection to an engine cylinder during a second, subsequent cylinder combustion event based on the indication of misfire.

10. The method of claim 9, wherein the adjusting includes advancing or retarding the fuel injection towards MBT.

11. A method, comprising:

igniting air-fuel mixture with a laser ignition device in an engine cylinder; and

adjusting an operating condition responsive to an indication of pre-ignition, the indication of pre-ignition based on an infra-red sensor.

12. The method of claim 11, wherein the indication of pre-ignition based on an infra-red sensor includes indicating pre-ignition based on an in-cylinder temperature profile estimated immediately preceding the laser ignition of the air-fuel mixture, and in the same cycle as the laser ignition, the cylinder temperature profile estimated by the infra-red sensor.

13. The method of claim 12, wherein the indicating includes indicating pre-ignition if a peak temperature of the in-cylinder temperature profile is higher than a threshold temperature and occurs more than a threshold duration before the laser ignition.

14. The method of claim 11, wherein adjusting an operating condition includes, adjusting one or more of a laser ignition timing and a cylinder fuel injection based on the indication.

15. The method of claim 13, wherein the in-cylinder temperature profile estimated immediately preceding the laser ignition of the air-fuel mixture is a first temperature profile, the method further comprising, indicating misfire based on a second in-cylinder temperature profile estimated by the infra-red sensor immediately following the laser ignition of the air-fuel mixture, and in the same cycle as the laser ignition.

16. The method of claim 15, further comprising, indicating cylinder knock based on output of a knock sensor coupled to an engine block.

17. A method for an engine, comprising:

increasing combustion temperature in response to infra-red information sensed in a cylinder, the infra-red information indicative of soot deposits.

18. The method of claim 17, wherein the engine is configured with laser ignition for igniting an air-fuel mixture in the cylinder, and wherein increasing combustion temperature includes increasing a power level of the laser ignition and directing the laser towards the soot deposit at least during expansion and exhaust strokes.

19. The method of claim 18, wherein infra-red information sensed in the cylinder includes an in-cylinder temperature profile estimated by an infra-red sensor during at least an intake and a compression stroke of a cylinder combustion event.

20. The method of claim 19, further comprising, in response to the infra-red information indicative of soot deposits, temporarily increasing an engine load to burn the soot deposits.