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US 9,851,204 B2Granted
Magnetormeter calibration for navigation assistance
AssigneeTexas Instruments Incorporated
InventorDeric Wayne Waters
Life of this patent
Estimating the term…
Abstract
Visual codes are scanned to assist navigation. The visual code may be a Quick Response (QR) code that contains information useful to calibrating a variety of navigation-based sensors such as gyroscopes, e-compasses, and barometric pressure sensors. Embodiments describe methods for magnetometer calibration and computing sensor orientation relative to users' local frame of reference. The embodiments use an initial yaw estimate, accelerometer, and gyroscope measurements along with other readily available information (the earth's magnetic field intensity, inclination angle, and declination angle).
Claims38
A system, comprising:
- an imaging device;
- a magnetometer sensor;
- a processor coupled to the imaging device and the magnetometer sensor,
- wherein the processor,
- causes the imaging device to scan a visual code and, based on scanning the visual code, the processor obtains a value indicative of a yaw angle of the system from the visual code and a value indicative of height of the visual code from the visual code,
- computes an estimate of a yaw angle of the system using a magnetometer measurement from the magnetometer sensor, accelerometer, and gyro measurements,
- compares the yaw angle read from the visual code to the computed estimate of the vaw angle to determine a quality factor, and
- recalibrates the magnetometer sensor when the quality factor indicates improper magnetometer sensor calibration.
5 more elements
A method, comprising:
- scanning a visual code;
- obtaining a value indicative of height of the visual code from the visual code;
- obtaining a value indicative of a yaw angle of an apparatus scanning the visual code from the visual code;
- computing an estimate of a yaw angle of the apparatus using a magnetometer measurement from a magnetometer sensor, accelerometer and gyro measurements;
- comparing the yaw angle read from the visual code to the computed estimate of the yaw angle to determine a quality factor, and
- recalibrating the magnetometer sensor when the quality factor indicates improper magnetometer sensor calibration.
3 more elements
A method, comprising:
- scanning a visual code;
- obtaining a value indicative of height of the visual code from the visual code;
- obtaining a value indicative of a yaw angle scanning the visual code from the visual code;
- obtaining a magnetometer measurement from a magnetometer sensor associated with the apparatus;
- computing a quality factor based on the yaw angle read from the visual code and a yaw angle computed from the magnetometer measurement;
- and
- recalibrating the magnetometer sensor when the quality factor indicates improper magnetometer sensor calibration.
4 more elements
A system, comprising:
- an imaging device;
- a magnetometer sensor;
- and
- a processor coupled to the imaging device and the magnetometer sensor,
- wherein the processor,
- causes the imaging device to scan a visual code and, based on scanning the visual code, the processor obtains a value indicative of a yaw angle of the system and a value indicative height of the visual code from the visual code,
- computes an estimate of a yaw angle of the system using a magnetometer measurement from the magnetometer sensor,
- compares the yaw angle read from the visual code to the computed estimate of the yaw angle to determine a quality factor, and
- recomputes the quality factor when the quality factor indicates improper magnetometer sensor calibration.
6 more elements
A system, comprising:
- an imaging device;
- a magnetometer sensor;
- and
- a processor coupled to the imaging device and the magnetometer sensor,
- wherein the processor,
- causes the imaging device to scan a visual code and, based on scanning the visual code, the processor obtains a value indicative of yaw angle and a value indicative of height from the visual code,
- computes an estimate of a yaw angle of the system using a magnetometer measurement from the magnetometer sensor,
- compares the yaw angle read from the visual code to the computed estimate of the yaw angle to determine a quality factor,
- recomputing the quality factor when the quality factor indicates improper magnetometer sensor calibration, and
- recalibrating the magnetometer sensor in response to the recomputed quality factor.
7 more elements
A method, comprising:
- scanning a visual code;
- obtaining a value indicative of a yaw angle from the visual code;
- obtaining a value indicative of height from the visual code;
- obtaining a magnetometer measurement from a magnetometer sensor associated with the apparatus;
- computing a quality factor based on the yaw angle read from the visual code and a yaw angle computed from the magnetometer measurement;
- recomputing the quality factor when the quality factor indicates improper magnetometer sensor calibration, and
- recalibrating the magnetometer sensor when the recomputed quality factor indicates improper magnetometer sensor calibration.
4 more elements
Dependencies are inferred from the claim text.