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:
Apr. 21, 1998
Filed:
Oct. 18, 1993
Satoshi Odagawa, Kawagoe, JP;
Pioneer Electronic Corporation, Tokyo-to, JP;
Abstract
A navigation apparatus displays a present position and an advance direction of a movable body on map information including road position information, and includes a measuring device for detecting a travelling distance and the advance direction and periodically measuring an advanced position, to update the present position. A method of correcting a distance error of the navigation apparatus includes the steps of: setting the present position as a first present position candidacy; positioning a plurality of second present position candidacies on positions corresponding to the road forward and backward of the first present position candidacy; measuring the advanced position with respect to each of the first and second present position candidacies as a standard position, on the basis of the detected travelling distance and advance direction; calculating a correction amount of each measured advanced position, to correct each measured advanced position onto a position corresponding to the road according to the road position information; selecting one of the first and second present position candidacies, which calculated correction amount is the minimum; and updating the present position by the corrected advanced position of the selected one candidacy.