A Calibration Method of Three-axis Magnetic Sensor Based on Ellipsoid Fitting

Abstract

It is very essential for a magnetic sensor to be calibrated before use because of various disturbances. However, Constrained by maneuverability of carriers, sample data distribute in a quite limited area, traditional calibration approach using ordinary least-square ellipsoid fitting algorithm makes large error or even cannot compensate properly. In this paper, a new onboard calibration method based on ellipsoid fitting is presented, without requiring external reference. Sample data are obtained in the restricted area by rotating carrier in three simple traces, ellipsoid coefficient are calculated using constrained least squares algorithm. The proposed method is contrasted with the traditional method via software simulation and experimental test; the results indicate that the new calibration method is stable and reliable, and superior to the traditional approach.