一种基于递推最小二乘法的运动平台剩磁差分测量与估计方法

Remanence Model Estimation Method of Geomagnetic Navigation Carrier Based on Recursive Least Square Method

地磁导航是通过对地球周围矢量磁场进行测量从而实现导航的一种方法.地磁导航在运动平台上应用的难点之一是平台剩磁对地磁测量的影响,严重污染了磁强计的测量.消除平台剩磁对地磁测量的影响成为地磁导航向应用转化的一项关键技术.为实现运动平台剩磁的有效测量与估计,提出了基于递推最小二乘法的运动平台剩磁差分测量与估计方法.基于载体干扰磁场值只与测量点到磁偶极子的距离和磁偶极子的磁矩有关的结论,根据磁偶极子的磁场分布特性,推导出一种基于内置磁强计阵列的运动平台剩磁差分估计模型,并通过递推最小二乘法求解差分估计模型.大量仿真实验表明,可以通过内置阵列磁强计对平台剩磁进行测量与估计,验证了所提出的平台剩磁估计方法的有效性.

Geomagnetic navigation is a method of in-situ measurement of magnetic field by the mag-netometer installed on the carrier platform to realize navigation.It is a passive navigation,which has the advantages of autonomy,strong anti-interference ability and no cumulative error.One of the difficulties in the application of geomagnetic navigation on moving platform is the influence of platform remanence on geomagnetic measurement,which seriously pollutes the measurement of magnetometer and becomes a key technology in the transformation of geomagnetic navigation to application.For example,the magnet-ic field distribution generated by ferromagnetic materials and the interference magnetic field generated by electrical equipment during work will pollute the measured value of the magnetometer,and then af-fect the accuracy of geomagnetic navigation.Aiming at the complicated problem of interfering magnetic field in geomagnetic measurement,this paper focuses on the effective measurement and estimation of the remanence of a moving platform.In order to realize effective measurement and estimation of remanence of moving platform,a method of differential measurement and estimation of remanence of moving plat-form based on recursive least square method is proposed.Firstly,the method is based on the conclusion that the carrier interference magnetic field value is only related to the distance between the measuring point and the magnetic dipole and the equivalent magnetic moment of the magnetic dipole in magnetic dipole theory,and the magnetic field distribution characteristics of the magnetic dipole.A remanence difference estimation model of moving platform based on built-in magnetometer array is derived,and the difference estimation model is solved by recursive least square method.Finally,a large number of simula-tion experiments show that the platform remanence estimation method can be measured and estimated by the built-in array magnetometer,which proves the effectiveness of the proposed method and lays a theoretical foundation for accurate geomagnetic navigation.