Real-time engine misfire detection method
First Claim
1. A powertrain control module for controlling the operation of an internal combustion engine comprising memory and a microprocessor programmed to:
- receive as inputs a plurality of engine operating parameters;
generate a predicted Karlovitz number (Kap) as a function of said plurality of engine operating parameters;
compare Kap to a threshold Karlovitz number (Kat) representing the value at which misfire occurs; and
indicate an engine misfire event if Kap >
Kat.
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Accused Products
Abstract
A method of detecting internal combustion engine misfires by generating a predicted Karlovitz number as a function of different engine operating conditions such as the air fuel ratio (AFR), the engine speed, the amount of exhaust gas recirculation (EGR), spark-ignition (SI) timing and the airflow rate. The predicted Karlovitz number is then compared against the threshold Karlovitz number in which misfire occurs. The threshold Karlovitz number is determined from a model for misfire predictions in engines and is stored in the electronic engine controller (EEC). A misfire is reported if the predicted Karlovitz number is greater than the threshold Karlovitz number. In another aspect of the invention, the predicted Karlovitz number is generated from submodels of laminar flame speed, laminar flame thickness, turbulence intensity, and turbulence integral length scale.
26 Citations
14 Claims
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1. A powertrain control module for controlling the operation of an internal combustion engine comprising memory and a microprocessor programmed to:
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receive as inputs a plurality of engine operating parameters; generate a predicted Karlovitz number (Kap) as a function of said plurality of engine operating parameters; compare Kap to a threshold Karlovitz number (Kat) representing the value at which misfire occurs; and indicate an engine misfire event if Kap >
Kat. - View Dependent Claims (2, 3, 4)
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5. A method of detecting misfire of an internal combustion engine comprising the steps of:
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determining a plurality of engine operating parameters; generating a predicted Karlovitz number (Kap) as a function of said plurality of engine operating parameters; comparing Kap to a threshold Karlovitz number (Kat) representing the value at which misfire occurs; and indicating an engine misfire event if Kap >
Kat. - View Dependent Claims (6, 7, 8, 9)
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10. In an internal combustion engine system controlled by a powertrain control module which receives as inputs a plurality of engine operating parameters and outputs a spark ignition (SI) control value, said powertrain control module including a microprocessor and associated memory, a method of detecting misfires of said engine comprising the steps of:
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generating a predicted Karlovitz number (Kap) as a function of said plurality of engine operating parameters; comparing Kap to a threshold Karlovitz number (Kat) representing the value at which misfire occurs; and indicating an engine misfire event if Kap >
Kat. - View Dependent Claims (11, 12, 13, 14)
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Specification