基于椭球假设的三轴磁强计标定算法改进  

Improved Calibration Algorithm About the Three-Axis Magnetometer Based on Ellipsoid Assumption

作　　者：刘艳霞[1,2] 李希胜[1] 窦晓霞[2] 

机构地区：[1]北京科技大学自动化学院,北京100083 [2]北京联合大学自动化学院,北京100101

出　　处：《计算机测量与控制》2013年第6期1590-1593,共4页Computer Measurement &Control

基　　金：国家自然科学基金(61273082);中央高校基本科研业务费专项资金(FRF-TP-09-017B);北京市属高等学校人才强教计划资助项目(PHR201108411);北京联合大学新起点计划项目(ZK201205)资助

摘　　要：首先对三轴磁力计误差机理进行分析,说明同一地点测量的地磁场矢量符合椭球假设;然后指出传统椭球拟合算法受粗差点影响,拟合后的椭球参数向量误差较大;根据平差理论引入权矩阵对算法进行改进,改进后的算法可以有效剔除粗差点,提高椭球拟合参数向量和校正矩阵的精度;实验表明,采用改进算法标定后,最大最小绝对误差由原来的100nT下降到29nT,均方根误差由21nT下降到6nT;改进算法求出的校正矩阵可直接用于另一组数据点的误差补偿,并取得比传统算法更好的补偿效果。Firstly, the error source of the three axis magnetometer is analyzed. The analysis shows that the magnetic field vector measuring at the fixed location comply ellipsoid assumption. It is pointed that the ellipsoid parameter vector error of traditional ellipsoid fitting algorithm is bigger owing to the influence of outliers. Weight matrix is introduced to improved algorithm based on the adjustment theory. Im proved algorithm can efficiently exclude the outliers and improved the precision of the ellipsoid fitting parameter vector and the correction ma trix. The experiment indicates that, calibrated by improved algorithm, the absolute error reduces from 100nT to 29nT and the RMS error re duces from 21nT to 6nT. The correction matrix deduced by improved algorithm can be directly used for the error compensation of another group of data points and obtain better result than the traditional algorithm.

关 键 词：椭球拟合 三轴磁强计 平差理论 权矩阵 

分 类 号：V241.611[航空宇航科学与技术—飞行器设计]