Research On Invariant Calibration Algorithm Of Three-axis Magnetometer Cross Array

With the development of the times and the progress of basic science,there are more and more algorithms in the field of geomagnetic detection,and these algorithms also put forward higher requirements for magnetic field detection equipment.Due to the excellent cost performance and measurement range,flux gate magnetic sensor has been applied to various fields requiring magnetic field detection.For this high-precision magnetometer,due to beyond human control such as manufacturing process and assembly environment,the output data of magnetometer is always inaccurate.For this problem,it is necessary to establish the corresponding system error model and calibrate the error parameters of the magnetometer,so as to make the output of the magnetometer more stable and reliable to meet the needs of practical work.However,the magnetometer is usually not used alone in the process of use,and there are different calibration methods in different scenes.This paper calibrates the cross array of magnetometer in the geomagnetic environment.In this paper,the error model of the magnetometer is analyzed under the condition of geomagnetic field.It is found that the magnetometer has systematic errors of zero bias error,non orthogonal error,misalignment error and scale factor error.Then,the first step calibration is completed by the adaptive residual least square method,and then the second step calibration is carried out by the orthogonal Procrustes analysis method.Through the analysis of the previous algorithm,some redundancy is found in the solution of misalignment error.In order to make full use of the data of the redundant part of the asymmetric error matrix,a single-step calibration algorithm is designed to calibrate other magnetometers with one magnetometer as the standard.In the front,the least square method of adaptive residual proves that under certain error conditions,the error parameters of magnetometer can be solved easily and quickly.The Kalman filter calibration algorithm is proposed to realize the real-time estimation of magnetometer error parameters.Then,the feasibility of the above three algorithms is verified by experiments,and the results are evaluated.It is found that both have good correction effect.