Invention Grant
- Patent Title: Method for aligning a mobile device surface with the coordinate system of a sensor
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Application No.: US13767838Application Date: 2013-02-14
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Publication No.: US09714955B2Publication Date: 2017-07-25
- Inventor: Mahesh Ramachandran , Arvind Ramanandan , Christopher Brunner , Murali Ramaswamy Chari
- Applicant: QUALCOMM Incorporated
- Applicant Address: US CA San Diego
- Assignee: QUALCOMM Incorporated
- Current Assignee: QUALCOMM Incorporated
- Current Assignee Address: US CA San Diego
- Agency: Kilpatrick Townsend & Stockton
- Main IPC: G01P21/00
- IPC: G01P21/00 ; G01C25/00

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.
Public/Granted literature
- US20140129170A1 METHOD FOR ALIGNING A MOBILE DEVICE SURFACE WITH THE COORDINATE SYSTEM OF A SENSOR Public/Granted day:2014-05-08
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