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:
Feb. 11, 1997
Filed:
Jun. 06, 1995
John M Prevost, Jackson, MI (US);
Chrysler Corporation, Auburn Hills, MI (US);
Abstract
An apparatus and method are provided for detecting cylinder misfires in an internal combustion engine of a motor vehicle which provides a good signal to noise ratio and is capable of distinguishing from noise related events such as misfire induced bobble and harsh clutching maneuvers. Crankshaft rotation is sensed and crankshaft velocities are measured for each cylinder. Changes in angular velocity are determined and correspond to each of a plurality of cylinder firing events. With a first averaging filter, angular velocity changes are sorted over a predetermined series of cylinder firings and the two middle angular velocity changes are averaged to provide an average change in velocity value. A deviation is determined between the change in angular velocity for a selected cylinder and the average change in velocity. With a second averaging filter, the deviations from the first averaging filter are sorted over a series of cylinder firings and the two middle most deviations are averaged to provide an average change of deviation thereof. A second deviation is determined between the change in the first deviation for a selected cylinder and the average deviation value. The second deviation is compared to a threshold value and a misfire event is determined for the selected cylinder based on the comparison. Any number of two or more cascade connected average filters may be employed.