基于自适应遗传算法的三轴磁强计校准

针对MEMS磁强计的精度无法满足姿态测量系统的航向角测量要求,对磁强计的误差来源进行了模型化分析,设计了一种基于自适应遗传算法的空间椭球磁强计校准方法.首先,采取自适应遗传算法,对磁强计测量的原始数据进行空间椭球的拟合,用估计的参数进行刻度系数、软磁干扰、硬磁干扰与零位偏置的综合误差补偿.其次,利用最小二乘法求解出非正交轴的方向余弦,进行非正交误差和安装误差的补偿.最后,将该方法应用到某姿态测量系统中,分别用未补偿和补偿后的数据进行姿态测量实验,实验结果表明该方法准确计算出磁强计的误差参数,使补偿后的航向角精度提高了6.8倍.

Calibration of three-axis magnetometer based on adaptive genetic algorithm

In view that the precision of MEMS magnetometer can not meet the heading measurement requirement of the attitude measurement system,the error source of a three-axis magnetometer is modeled and analyzed,and a calibration method based on ellipsoid fitting and adaptive genetic algorithm is proposed.The adaptive genetic algorithm is employed to fit an ellipsoid using raw data obtained by the three-axis magnetometer,and the output data is corrected by using the ellipsoid estimated parameters to compensate offset,scale factors,hard iron and soft iron.The three-axis direction cosines of the sensor are fitted by least square method so that the calibration of the sensor can remove the non-orthogonality and mounting error.Finally,the proposed calibration method is applied to an attitude reference system to conduct the heading measuring experiments using raw data and calibrated data.Experiment results demonstrate that the heading deviation range is reduced to 0.7° from 4.5°,which shows that the heading accuracy is increased by 6.8 times.