Method for aligning a mobile device surface with the coordinate system of a sensor
US9714955B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 2013 |
| Grant date | Jul 25, 2017 |
| Priority date | — |
| Expiry date | Jun 25, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01C25/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An accelerometer in a mobile device is calibrated by taking multiple measurements of acceleration vectors when the mobile device is held stationary at different orientations with respect to a plane normal. A circle is calculated that fits respective tips of measured acceleration vectors in the accelerometer coordinate system. The radius of the circle and the lengths of the measured acceleration vectors are used to calculate a rotation angle for aligning the accelerometer coordinate system with the mobile device surface. A gyroscope in the mobile device is calibrated by taking multiple measurements of a rotation axis when the mobile device is rotated at different rates with respect to the rotation axis. A line is calculated that fits the measurements. The angle between the line and an axis of the gyroscope coordinate system is used to align the gyroscope coordinate system with the mobile device surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.