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:
Jan. 03, 1995
Filed:
Sep. 01, 1993
John V James, Walled Lake, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A system and method compensates for systematic irregularities in measured engine velocities caused by torsional flexing in the crankshaft during rotation to improve the accuracy of misfire detection. The present invention compensates for irregularities in 'Profile-Ignition-Pick-Up interval' (PIP interval) timing. These irregularities are systematic with respect to different engine cylinders. The present invention is configured to function with a processor unit. Correction factors for each of the n PIP intervals of an engine cycle are generated for each of a multitude of engine operating conditions, where n is the number of cylinders in the engine. Each set of n generated correction factor is stored in a table (a 'look-up table' located in a memory unit) having a corresponding unique address location. This table is typically determined empirically in the calibration of the engine type by a test engine. The correction factors are generated while the test engine is rotated at a fixed steady state operating point with combustion, where the operating point is typically a particular speed and load.