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:
Jul. 06, 2004
Filed:
Apr. 11, 2000
Patrick Fong Wing Hon, Hong Kong, HK;
Johnny Tam Ping Wah, Hong Kong, HK;
Electronics Tomorrow Limited, Hunghom, HK;
Abstract
A method and system for continuously and automatically calibrating the settings of an electronic compass, as needed, while a vehicle moves from place to place is shown. The calibration technique of the present invention measures the ocal magnetic field while the vehicle moves from place to place and determines points on a reference Cartesian coordinate system. Each such point defines the endpoint for a vector corresponding with the measured field intensity and orientation of the local magnetic field. Any three such points are used to calculate the center of a circle that extends through all of those points. A vector that begins at the origin of the reference Cartesian coordinate system and terminates at the calculated center of the circle is thereafter subtracted from subsequent field measurement vectors that correspond to the field intensity and direction of the local magnetic field. As a result, the electronic compass compensates for interfering magnetic fields, including those resulting from the varying magnetic field signatures of its associated vehicle.