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. 23, 1996
Filed:
Feb. 26, 1993
William B Ribbens, both Ann Arbor, MI (US);
Jaehong Park, both Ann Arbor, MI (US);
The Regents of the University of Michigan, Ann Arbor, MI (US);
Abstract
Engine misfire is detected in a reciprocating internal combustion engine having an engine cycle frequency in the frequency domain from crankshaft angular velocity. Crankshaft angular position is sensed to develop an electrical signal which is a function of the crankshaft angular velocity. The electrical signal contains data which is sampled. The sampled data is transformed to an equivalent frequency domain spectrum including frequency components of the engine cycle frequency and harmonics thereof. A statistical decision algorithm is applied to the magnitudes of the frequency components to distinguish between a true misfire and normal cyclic variability which characterizes the combustion process. In one embodiment, the misfired cylinder is identified based on the phase of the frequency component at the engine cycle frequency. In another embodiment, the identity of the misfired cylinder is determined by shifting the sampled data prior to transforming the data.