| With the increasing demand for military weapons and civilian magnetic information acquisition,it is of great significance to develop a triaxial magnetic sensor with high resolution,high sensitivity and high orthogonality.TMR triaxial integrated magnetic sensor adopts the technology of "magnetic changing track",which has obvious advantages in improving resolution,triaxial orthogonality,linearity and other performance indexes.However,the miniaturization and integration of the triaxial magnetic sensor will lead to the problem of inter-axial error.The specific sources include the coupling of multi-physical fields between the axes,the installation deviation of the sensitive body and the difference of the parameters of inter-axial magnetic regulation,which will reduce the accuracy of the three-component solution of the magnetic sensor.Therefore,this paper studies the mechanism of axial error and signal decoupling method based onTMR triaxial integrated magnetic sensor,aiming to reduce the parameter calibration and decoupling result error of TMR triaxial integrated magnetic sensor,so as to improve the orthogonality and measurement accuracy of the triaxial magnetic sensor.The main research work and innovations are as follows:1.The mechanism of inter-axial error of the TMR triaxial integrated magnetic sensor was systematically analyzed,the decoupling model of the magnetic sensor was established,and the main factors affecting the inter-axial error of the magnetic sensor were simulated and studied.Based on the structure and principle of the TMR triaxial integrated magnetic sensor,the mechanism of the axial error caused by the coupling of multi-physical field between the magnetic sensor axes,the deviation of the installation Angle of the magnetic sensor and the difference of the magnetic control parameters between the axes was analyzed.The influence of magnetic field on output signal measured by magnetic sensor is studied.In order to solve the problem that there are many factors affecting the inter-axial error of the TMR triaxial integrated magnetic sensor,the influence of the coupling of the inter-axial compensation coil,the deviation of the installation Angle of the sensitive body and the difference of the parameters of the inter-axial magnetic regulation on the accuracy and orthogonality of the three-component solution of the magnetic field are simulated and analyzed.The simulation results show that the influence of axial magnetic regulation parameters,axial coil coupling,and sensor installation Angle deviation on the accuracy of three-component magnetic field calculation decreases successively.Based on the simulation results,the requirements of parameter calibration and error calibration of magnetic sensor are clarified.2.Aiming at the problem of low decoupling accuracy of magnetic sensor,a high precision parameter calibration and three-component decoupling correction method for TMR three-axis integrated magnetic sensor was established.Aiming at the problems caused by the unfixed coordinate system and the weak applicability of the calibration method in the current calibration of the magnetic sensor,such as the orbit change coefficient,the installation Angle deviation of the sensitive body and the poor precision of the coil parameter calibration results,a parameter calibration method based on the attitude change of the magnetic sensor is proposed.By analyzing the turntable error introduced in the calibration,a turntable error correction model is established to correct the calibration error of the magnetic sensor parameters and improve the calibration accuracy of the structure parameters.This paper studies the decoupling and orthogonality of three components of magnetic sensor,establishes the decoupling model of magnetic sensor and the evaluation method of non-orthogonality of three axes,and improves the decoupling method of three components of magnetic field based onTMR three-axis integrated magnetic sensor.3.The magnetic field decoupling experiment of the magnetic sensor was carried out to verify the correctness of the magnetic sensor model and the feasibility of the decoupling correction method.The magnetic field decoupling experiment system is constructed with three axis non-magnetic manual turntable,high-precision magnetic source and high-digit data acquisition card,and the decoupling experiment is designed and carried out.The parameters calibration experiment was carried out on the TMR triaxial integrated magnetic sensor prepared by the research group.The experimental results showed that the rail conversion efficiency of the magnetic sensor was 31.81%,37.01%,31.21% and33.81% respectively.The initial magnetic field of the magnetic sensor is 1856 nT,582 nT,-554 nT and 717 nT respectively,which is close to the design theoretical value of the magnetic sensor.After three component calculating magnetic field experiment was carried out,in the magnetic shielding room,provide the calibration of the magnetic source is 100000 nT,the sensitive body samples of magnetic sensor resolution for 7nT,different posture change magnetic sensor,magnetic sensor calculating three-component error 92 nT,maximum total 141 nT,maximum error calculating non-orthogonal maximum 0.25°,and the sensitive body resolution is consistent with theoretical analysis the index.Analysis based on existing experimental results show that if the residual magnetic fluctuation in the test environment is up to 1nT and the resolution of the sensitive body of the magnetic sensor is up to 2pT,the decoupling method proposed in this paper can realize the total error of the solution within 0.01% and the degree of non-orthogonality of the three axes below 0.05. |
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