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:
Jun. 25, 2002
Filed:
Apr. 02, 2001
James C. Bach, Carmel, IN (US);
Kevin M. Gertiser, Noblesville, IN (US);
Delphi Technologies, Inc., Troy, MI (US);
Abstract
An improved method of measuring vehicle speed based on the output signal of a variable reluctance speed sensor responsive to the teeth of a transmission output gear adjusts the sensitivity of a signal processing circuit in dependence on the mode of operation of the vehicle so as to reduce sensitivity to output signals produced by gear tooth vibration. The signal processing circuit only passes portions of the sensor output signal that have an amplitude greater than a predefined threshold and a frequency less than a predefined frequency, except when an electronic controller identifies a condition of potentially erroneous speed sensing characterized by substantially stationary vehicle operation with the engine decoupled from the output gear and an engine speed in excess of a calibrated threshold. Under the identified condition, the controller reduces the sensitivity of the signal processing circuit by raising the predefined amplitude threshold and lowering the predefined cut-off filter frequency so that only large amplitude, low frequency signals are passed.