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:
Oct. 27, 1998
Filed:
May. 22, 1997
Shigeki Aoshima, Susono, JP;
Tomohisa Harada, Aichi-ken, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
In a vehicle mounted satellite signal receiving apparatus which adopts a satellite tracking system combining a gyro tracking with a hybrid tracking, there is provided a device which can revise an offset error correction value of a gyro sensor, even if there is a drift in the offset error. In this device, gyro tracking is performed when a reception level is a threshold value L.sub.C or more. The gyro tracking is performed by setting an antenna at an angular velocity .omega., which is derived from an equation,.omega.=-.omega.G+.DELTA..omega.G, where -.omega.G is a value resulted from conversion of sign for gyro angular velocity .omega.G, and .DELTA..omega.G is a prescribed offset error correction value. A reception level declines if the offset error correction value .DELTA..omega.G deviates and therefore an apparent offset error arises in the gyro sensor. When the reception level declines below a threshold value L.sub.B, the aforementioned offset error correction value .DELTA..omega.G is revised, basing on the direction of an angular velocity .omega.S which is used in the hybrid tracking (or step tracking).