基于无迹卡尔曼滤波和设备的三轴磁强计校正

采用无迹卡尔曼滤波(unscented Kalman filter,UKF)磁强计模型参数估计方法,提出对三轴磁强计的总量及分量误差进行校正。采用高精度质子磁力仪提供磁场基准值,借助无磁转台实现磁强计全方位转动,对一款DM-050三轴磁强计进行了参数估计,并将参数估计值运用到总量和分量校正。仿真结果表明,参数估计值与磁强计实际参数值一致。校正后,磁强计总量误差从427.9 nT减少到2.06 nT;X、Y、Z轴分量误差分别减少到1.84 nT、1.96 nT、1.72 nT。而且证明了UKF对磁强计模型参数估计的重复性良好,并研究了噪声幅度大小对UKF的性能影响程度。实验结果表明,磁强计误差从114.94 nT减少到14.47 nT,表明该方法能有效提高磁强计测量精度。

Error calibration of three axis magnetometer based on UKF and equipment

The model parameter estimation method based on unscented Kalman filter(UKF) is proposed to calibrate the scalar and vector errors of three axis magnetometer.A high precision proton magnetometer is used to measure the true value of the magnetic field scalar;a nonmagnetic turntable is used to rotate the magnetometer omni-directionally and the calibration model parameters are estimated after rotation.Using this method,the parameters of a DM-050 magnetometer are estimated,and these estimated parameters are used to calibrate its scalar and vector errors.Simulation results show that the estimated parameters are consistent with the actual parameters.After calibration,the scalar error is reduced from 427.9 nT to 2.06 nT;the vector errors of X,Y,Z axes are reduced to 1.84 nT,1.96 nT and 1.72 nT,respectively.In addition,the method using UKF to estimate magnetometer model parameters is proved to have good repeatability;and the influence of noise on the UKF performance is discussed.Experiment results show that the magnetometer error is reduced from 114.94 nT to 14.47 nT,which indicates that the proposed method can improve the precision of three axis magnetometer.