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:
Sep. 20, 1994
Filed:
Jun. 22, 1992
Yutaka Masumoto, Saitama, JP;
Satoshi Odagawa, Saitama, JP;
Pioneer Electronic Corporation, Tokyo, JP;
Abstract
When the body of an automobile equipped with a stand-alone navigation system is magnetized by an external magnetism, an unknown magnetization vector is determined by correcting the known magnetization vector. Even very small changes in the magnetization vector can be corrected without putting a burden on the user of the automobile. A magnetization vector directed from a reference position toward the center of a magnetic circle which indicates the magnetized condition of the automobile body is detected, and a geomagnetic vector which is directed from the reference position in the direction in which the mobile body progresses is detected. An instantaneous direction vector which is directed from the center of the magnetic circle in the direction in which the mobile body progresses and which has a direction angle is calculated. Then, an average geomagnetic intensity is calculated from the average of past values of the magnitude of the instantaneous direction vector, and a weighting coefficient that is a positive real number of or less than 1 is calculated based on the average geomagnetic intensity. A substantially instantaneous magnetization vector for correcting the magnetization vector is calculated. Thereafter, a corrected magnetization vector is calculated from the magnetization vector, the weighting coefficient, and the substantially instantaneous magnetization vector.