摘要
地磁场矢量可描述成卫星的位置函数,利用三轴磁强计观测地磁场矢量或模,可实现近地卫星在任何运行状态下的自主导航,但是由于地球磁场模型存在不确定性和长期变化性,三轴磁强计存在安装误差和未知比例因子等误差因素,所以目前单一使用三轴磁强计进行自主导航精度有限。提出一种利用地磁场信息在轨修正地磁场模型高斯系数和标定三轴磁强计模型误差的新方法,通过将三轴磁强计与地磁场模型参考值的矢量和模分别作差,推导两种差值与地磁场模型高斯系数和三轴磁强计模型误差参数的数学关系,设计先进滤波算法得到高斯系数及误差参数的最优估计,实时修正地磁场模型和三轴磁强计模型。以某低轨卫星利用地磁场进行自主导航为例,利用数值仿真验证在轨修正后地磁场模型和标定后三轴磁强计模型,并对3种自主导航方法进行仿真结果的分析和比较,论证所设计方法既提高系统导航精度、收敛性和稳定性,又有利于工程实际应用。
The geomagnetic field vector is a function of the satellite＇s position. Autonomous LEO satellite navigation can be achieved based on the measurement data of the onboard three-axis magnetometers. Because of the indefinitness and long-term variableness existing in the magnetic field, the navigation precision is limited when only using a single magnetometer. A new method of modifying the magnetic Gauss parameter and calibra- ting the magnetometer model error based on magnetic information is presented. Firstly, the integer measure- ment model of three-axis magnetometer is established. The mathematieal models of the magnetic Gauss parame ter and three-axis magnetometers are deduced, which connects with magnetic information. The optimal estimate of error parameters is obtained by an advanced filter method. Secondly, the LEO satellite is analyzed by the magnetic field. The integrated navigation method and algorithm are designed and simulated. Finally three re- sults of computer simulation show that the proposed method can not only improve the navigation precision and convergence but also perfectly be applied to engineering practice.
出处
《系统工程与电子技术》
EI
CSCD
北大核心
2012年第8期1660-1667,共8页
Systems Engineering and Electronics
关键词
地磁场高斯系数
修正参数
三轴磁强计
在轨标定
magnetic Gauss parameter
modifying parameter
three-axis magnetometer
calibrating on orbit
