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. 14, 1993
Filed:
Jun. 24, 1991
Erik B Vigmostad, Fairfield, IA (US);
Robert D Klauber, Fairfield, IA (US);
Frederick P Sprague, Fairfield, IA (US);
Sensortech, L.P., Fairfield, IA (US);
Abstract
Disclosed are a method and apparatus for comparing torsional stress/strain states of a power transmitting member of an internal combustion engine to detect an abnormal combustion condition, including misfire, knock or roughness. Statistical processing steps may be used to detect an abnormal combustion event including: calculating a mean and standard deviation for a set of signals related to the torsional stress induced in the power transmitting member, calculating a difference between a later signal and the mean, calculating a ratio of the difference to the standard deviation, and comparing the ratio to a threshold. The ratio so obtained from a given cylinder may further be compared with one or more other such ratios from other cylinders. A magnetostrictive sensor may preferably be used to obtain the signals relating to the torsional stress in the power transmitting member, such as the engine crankshaft. In addition, the magnetostrictive sensor may include windings to cancel induced electromagnetic interference signals.