Invention Grant
- Patent Title: Calibration of temperature effect on magnetometer
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Application No.: US14703147Application Date: 2015-05-04
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Publication No.: US09599694B2Publication Date: 2017-03-21
- Inventor: Nazih Almalki , Robert George Oliver
- Applicant: BlackBerry Limited
- Applicant Address: CA Waterloo, Ontario
- Assignee: BlackBerry Limited
- Current Assignee: BlackBerry Limited
- Current Assignee Address: CA Waterloo, Ontario
- Agency: Rowand LLP
- Main IPC: G01R35/00
- IPC: G01R35/00 ; G01C19/00 ; G01R33/07 ; G01C17/38

Abstract:
A method for calibrating a magnetometer following a temperature event is described. The magnetometer includes three sensors, including a Hall Effect sensor associated with a first sensing axis and a sensor of another type associated with a second sensing axis. The method includes: maintaining a cache of gyroscope data and magnetometer data representing magnetometer readings obtained from the magnetometer; detecting a temperature event; determining an expected magnetometer reading following the temperature event; comparing the expected magnetometer reading to a magnetometer reading obtained from the magnetometer after the temperature event to determine a calibration correction amount; compare a difference between the magnetometer reading obtained after the temperature event and the expected magnetometer reading for the second sensing axis to a threshold and, based on the comparison to the threshold, generating new calibration data for the magnetometer based on the calibration correction amount.
Public/Granted literature
- US20160327627A1 CALIBRATION OF TEMPERATURE EFFECT ON MAGNETOMETER Public/Granted day:2016-11-10
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