The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 21, 1999
Filed:
May. 03, 1999
Wengang Dai, Canton, MI (US);
Rodney John Tabaczynski, Saltine, MI (US);
Nizar Trigui, Ann Arbor, MI (US);
Ford Global Technologies, Inc., Dearborn, MI (US);
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.