载体干扰磁场补偿方法

The vehicle interferential magnetic field compensation method

获得载体航行路径上各点地磁场的精确测量值是地磁匹配导航的前提,而载体上各种干扰磁场的存在会引起磁力仪输出的偏差,影响匹配的精度,因此必须对载体干扰磁场进行补偿。在分析载体干扰磁场特性的基础上,提出利用矢量测量值对地磁场总场值进行补偿的方法。该方法首先根据矢量磁力仪的测量模型得到关于载体磁场参数的非线性方程,然后采用非线性参数估计方法估计出精确的载体干扰磁场系数,最后再利用估计结果对测量值进行补偿。通过仿真对该方法的有效性进行研究,并设计了半实物实验对其实用性进行验证。结果表明采用本文提出的方法补偿后地磁场总场值的测量误差在20nT以内,而且该方法参数估计精度高,应用方便,可以有效地对导航载体干扰磁场进行补偿。

Getting accurate geomagnetic field measurements on the route of the vehicle is the precondition for geomagnetic navigation.The interferential magnetic field of the vehicle would distort the outputs of the magnetometer and influence the matching precision,so it must be compensated.Based on the analysis of the characteristics of the vehicle magnetic field,a method to compensate the geomagnetic magnitude,using vector measurements,is presented.A formulation was derived according to the measurement model of vectorial magnetometer,a nonlinear evaluation method was adopted to evaluate the vehicle interferential fields parameters,and then the evaluated results were used to compensate the real-time measurements.A simulation was conducted to test the effect of the method and an experiment was performed to validate its practicability.The results show that after compensating with the presented method,the measurement error of geomagnetic field magnitude is less than 20nT,indicating that the method has high compensating precision,good convenience in use,and can compensate the interferential magnetic field of the navigation vehicle effectively.