一种地磁导航中的低频电磁干扰场分离方法

Method for separation of low-frequency electromagnetic interference in geomagnetic navigation systems

摘要:

为解决地磁导航中电气设备所产生的低频干扰磁场对导航系统所产生的不利影响,针对磁场干扰方向时变所导致的非线性叠加问题,提出了将干扰电路的各个支路根据电流变化特性分组划分成不同干扰源的办法,以确保各干扰源产生方向固定的干扰场.并对载体的运动姿态提出了要求,从而建立了磁场信号的线性化叠加模型.针对独立特征量分析法固有的幅值与顺序模糊性缺陷,提出采用相关系数的绝对值来进行搜索匹配定位.理论分析与仿真实验证明了本方案可有效分离出地磁信号的波形并进行精准匹配.

Abstract:

This work proposed a method to separate the low-frequency magnetic interference induced by the electrical equipment during geomagnetic navigation process.Firstly,the branches of a circuit are divided into several independent interference source based on electrical analysis,and the attitude of the carrier is regulated to make sure that the total strength measured along each sensor’s axis is the linear superposition of all field components(including geomagnetic field and interferences).Secondly,to compensate the ambiguity drawbacks of Independent Components Analysis(ICA) method,the absolute value of correlation coefficient is proposed to perform map matching.Both theoretical deduction and simulation results have proved the efficiency of the method.