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. 14, 1999
Filed:
Oct. 09, 1997
Per Krogh Hansen, Burlington, VT (US);
Vladimir Kogan, S. Burlington, VT (US);
Ascension Technology Corporation, Burlington, VT (US);
Abstract
In a sourceless orientation sensor, the sensor measures the three orientation angles azimuth, elevation and roll in a fixed reference three-dimensional coordinate frame. The sensor utilizes a three-axis magnetic sensor to measure changes in the Earth's magnetic field in order to determine the azimuth and roll (or elevation) angles after the elevation (or roll) angle has been determined by other means. A first embodiment utilizes a separate sensor to measure the elevation (or roll) angle in a fixed reference three-dimensional coordinate frame while a three axis magnetic sensor is used to measure the Earth's magnetic field. The azimuth and the roll (or elevation) angles are then determined from these measurements. A second embodiment utilizes a combination of a three-axis accelerometer to sense the Earth's gravity to measure the absolute elevation and roll angles for slow motions and a two-axis rate sensor to measure the azimuth and elevation velocities in the sensor frame. A direct method employing translation and integration is used to find the azimuth and elevation angles in the fixed reference three-dimensional coordinate frame. The roll angle is then found from the magnetic sensor measurements. Other embodiments are disclosed.