Method and system for laser ignition control
First Claim
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1. An engine method, comprising:
- dynamically adjusting a laser intensity of an engine laser ignition device during a cylinder ignition event via closed-loop control based on a monitored cylinder flame quality, increasing an amount of current drawn from a battery of an engine into the laser ignition device to increase the laser intensity, and decreasing the amount of current drawn from the battery of the engine into the laser ignition device to decrease the laser intensity.
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Abstract
Methods and systems are provided for closed-loop adjusting a laser intensity of a laser ignition device of a hybrid vehicle. The laser intensity applied over consecutive laser ignition events is decreased until a flame quality is degraded for a threshold number of cylinder combustion events. The laser intensity is then increased to improve flame quality and the closed-loop adjustment is reiterated.
23 Citations
18 Claims
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1. An engine method, comprising:
dynamically adjusting a laser intensity of an engine laser ignition device during a cylinder ignition event via closed-loop control based on a monitored cylinder flame quality, increasing an amount of current drawn from a battery of an engine into the laser ignition device to increase the laser intensity, and decreasing the amount of current drawn from the battery of the engine into the laser ignition device to decrease the laser intensity. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for a hybrid vehicle engine including a laser ignition system, comprising:
following a laser ignition event of the engine, reducing a laser intensity at a plurality of subsequent laser ignition events of the engine until an inferred combustion flame quality reaches a threshold, the inferred combustion flame quality based on a photodetector coupled to the laser ignition system; and then increasing the laser intensity responsive to reaching the threshold, wherein the photodetector is configured for infra-red detection and wherein the inferred combustion flame quality based on the photodetector includes estimating a peak in-cylinder temperature following each laser ignition event based on an output of the photodetector and the inferred combustion flame quality is degraded when the estimated peak in-cylinder temperature is lower than a threshold. - View Dependent Claims (13, 14, 15, 16, 17)
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18. A hybrid vehicle system, comprising:
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an engine including a cylinder, the cylinder including a piston; an electric motor-generator coupled to a battery; a battery-operated laser ignition device coupled to a cylinder head; a photodetector configured for infra-red detection coupled to the laser ignition device; and a controller with computer readable instructions for; at each ignition event, estimating a flame quality inside the cylinder using the photodetector; in response to the estimated flame quality being higher than a threshold, reducing a laser intensity of the laser ignition device at a subsequent ignition event; and in response to the estimated flame quality being lower than the threshold, increasing the laser intensity of the laser ignition device for a threshold number of ignition events, wherein reducing the laser intensity of the laser ignition device includes drawing a smaller current from the battery into the laser ignition device, and wherein increasing the laser intensity of the laser ignition device includes drawing a larger current from the battery into the laser ignition device.
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Specification