Geomagnetic Sensor Offset Correction via Virtual Sphere Reference
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Solution Overview
Problem
Geomagnetic sensing devices face challenges in accurately correcting offset errors after calibration due to environmental influences like temperature and magnetic fields, leading to instability in high-accuracy measurements of angular velocity and azimuth.
Innovation Solution
A geomagnetic sensing device with a controller that extracts output coordinate points deviated from a virtual circle or sphere, updates a reference point by moving along virtual straight lines, and converges on a new reference point to correct offset errors, reducing operational burden and achieving precise corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration is performed to obtain a reference point of the magnetic sensor output, then the initial measurement accuracy is improved, but offset errors occur after calibration due to environmental influences
Solution Approach 1:
The patent performs preliminary calibration to establish a reference point before actual measurements. This preliminary action creates a baseline that can be used for subsequent offset error corrections, allowing the system to anticipate and compensate for environmental drifts that occur after calibration.
Solution Approach 2:
The patent implements a feedback mechanism where the magnetic sensor continuously monitors its output, compares it against the calibrated reference point, and automatically calculates correction values. This feedback loop detects offset errors caused by environmental changes and applies real-time corrections to maintain measurement accuracy.
2Device complexity
If traditional offset correction methods are used, then the device complexity is reduced, but high-accuracy measurement of angular velocity and azimuth cannot be stably achieved
Solution Approach 1:
The magnetic sensor system performs self-correction by automatically detecting its own offset errors and applying corrections without external intervention. The system uses its own calibrated reference point to identify deviations and generates correction values autonomously, eliminating the need for complex external correction mechanisms while maintaining high measurement accuracy.
Data Source
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AI summary
[Object] To provide a geomagnetic sensing device including correcting means capable of correcting an offset error generated after calibration. [Solution] A controller 10 includes a calibration unit 10a, an offset error correcting unit 10b, an operation unit 10c, and the like. The calibration unit 10a obtains a reference point Og of an output of a magnetic sensor, and performs offset correction. The offset error correcting unit 10b is capable of performing operation processing for both the correction of a major offset error and the correction of a minor offset error by using a radius R (the magnitude of a geomagnetic vector) of a virtual circle or a virtual sphere (see Figs. 4 and 5), appropriately and easily correcting the offset error with a small amount of operation, and reducing the burden to the controller 10.