Sourceless orientation sensor
US5953683A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1997 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Oct 9, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C17/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
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 sens…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.