Adaptive Magnetometer Calibration Quality Threshold

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Solution Overview

Problem

Magnetometers in mobile devices face calibration challenges due to changing environmental conditions and magnetic interference, affecting their accuracy and requiring frequent recalibrations to maintain reliable magnetic field measurements.

Innovation Solution

A method for calibrating magnetometers on mobile devices involves determining the current quality level of magnetometer readings and adjusting the quality threshold for background calibration, allowing for ongoing and adaptive calibration processes triggered by environmental changes or user interactions, using a combination of foreground and background calibration techniques to ensure accurate readings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If frequent recalibration is performed to maintain accuracy under changing environmental conditions, then measurement reliability is improved, but device complexity and processing power consumption increase

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidcalibration process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic calibration quality threshold adjustment based on real-time magnetometer reading quality assessment. The system automatically lowers the calibration quality threshold when current readings exceed the threshold, enabling adaptive calibration frequency that responds to environmental stability rather than performing fixed frequent recalibrations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms where magnetometer reading quality is continuously assessed and fed back into the calibration decision process. This feedback loop enables the system to determine when recalibration is actually needed based on real-time quality metrics rather than relying on predetermined schedules.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If background calibration quality threshold is lowered to reduce processing power consumption, then energy efficiency is improved, but calibration accuracy may deteriorate

Engineering Contradiction:
Improveprocessing power consumptionVSAvoidcalibration accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The patent dynamically adjusts the calibration quality threshold based on real-time assessment of magnetometer reading quality. When readings indicate high stability and accuracy, the system lowers the threshold to reduce processing requirements. When quality deteriorates, the threshold is raised to maintain calibration standards, creating a self-regulating system that balances accuracy and energy consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the calibration quality threshold parameter dynamically based on environmental conditions and reading quality. This parameter adjustment allows the system to operate with different accuracy requirements under different conditions, optimizing the balance between measurement precision and processing power consumption.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2447667B1System and method for calibrating a magnetometer according to a quality threshold
Publication Date: 2015.11.11 BLACKBERRY LTD
  • EP2447667B1 patent drawingFigure 1~2
  • EP2447667B1 patent drawingFigure 3~4
  • EP2447667B1 patent drawingFigure 5

AI summary

A method and system are provided for calibrating a magnetometer. The method comprises determining a current quality level associated with magnetometer readings obtained using an active set of calibration parameters; and lowering a quality threshold for a background calibration of the magnetometer when the current quality level exceeds a threshold quality level needed by an application utilizing the magnetometer readings.