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:
Oct. 15, 1991
Filed:
Aug. 24, 1990
James M Dosdall, Grosse Ile, MI (US);
John V James, Walled Lake, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
Engine crankshaft velocity is determined during each firing interval of an engine. Pairs of velocities are combined to yield acceleration measurements indicating the work done by a particular cylinder in its power stroke. A deviation of a particular acceleration value from that of neighboring values denotes a lack of power in the corresponding cylinder. The width and the phase of each velocity interval are used which provide accurate and substantially independent acceleration measures for each power stroke. Specifically, the width of each interval is preferably between about 45.degree.-180.degree. of engine rotation. Each interval has a phase in relation to its respective power stroke such that the drop in acceleration occurring in a particular power stroke causes a maximum drop in the calculated acceleration corresponding to that particular power stroke and causes a smaller but substantially equal drop in the calculated accelerations corresponding to the preceding and following power strokes. The velocity measurement intervals can be defined by position reference marking signals generated at rotational positions corresponding to a point within the power strokes where a maximum acceleration would approximately occur during a proper firing of the power stroke.