Closed-loop ignition timing control
First Claim
1. A closed-loop ignition timing control method for timing application of an ignition signal to a spark plug for igniting an air-fuel mixture in an engine cylinder during a cylinder combustion event, comprising the steps of:
- referencing a base ignition timing command;
varying the base ignition timing command in accordance with an ignition timing variation value;
applying the ignition signal to the spark plug in accordance with the varied base ignition timing command to initiate a cylinder combustion event;
transducing cylinder combustion plasma ion content into an ion content output signal during the cylinder combustion event;
determining cylinder combustion plasma ion content variation as a function of the ion content output signal; and
varying ignition timing in response to the determined cylinder combustion plasma ion content variation in direction to minimize the variation.
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Accused Products
Abstract
Internal combustion engine ignition timing control for timing combustion events of an air-fuel mixture in engine cylinders in response to cylinder mean effective pressure feedback information. Cylinder mean effective pressure information is provided through monitoring of variation in ion content in cylinder combustion plasma through ionization current variation measurement and integration. Ion content variation monitoring is carried out at varying ignition timing angles and ignition timing is driven toward timing associated with a minimum ion content variation corresponding to a preferred ignition timing associated with maximum combustion efficiency.
61 Citations
10 Claims
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1. A closed-loop ignition timing control method for timing application of an ignition signal to a spark plug for igniting an air-fuel mixture in an engine cylinder during a cylinder combustion event, comprising the steps of:
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referencing a base ignition timing command; varying the base ignition timing command in accordance with an ignition timing variation value; applying the ignition signal to the spark plug in accordance with the varied base ignition timing command to initiate a cylinder combustion event; transducing cylinder combustion plasma ion content into an ion content output signal during the cylinder combustion event; determining cylinder combustion plasma ion content variation as a function of the ion content output signal; and varying ignition timing in response to the determined cylinder combustion plasma ion content variation in direction to minimize the variation. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An internal combustion engine ignition timing control method for controlling the timing of issuance of an ignition drive command for initiating combustion of an air-fuel mixture in an engine cylinder, comprising the steps of:
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providing at least a first and second ignition timing command; for each provided ignition timing command, (a) issuing the ignition drive command at the timing of the provided ignition timing command to initiate the combustion, (b) transducing ion content in the engine cylinder into an ion content signal following issuance of the ignition drive command, and (c) determining ion content variation in the engine cylinder as a function of the ion content signal; identifying the relative magnitude of the ion content variation for the provided ignition timing commands; adjusting a base ignition timing command away from a provided ignition timing command having a relatively high ion content variation and toward a provided ignition timing command having a relatively low ion content variation; and controlling ignition timing in accordance with the adjusted base ignition timing command. - View Dependent Claims (8, 9, 10)
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Specification