微小卫星三轴磁强计测量误差校正方法

Error Calibration Method of Three-axis Magnetometer Measurement for Micro-satellite

微小卫星在轨进行磁阻尼和磁定姿时,要利用三轴磁强计测量磁场强度,由温度变化引起的测量误差大大降低了测量精度,因而要对测量误差进行校正。文章提出一种校正方法,通过分析三轴磁强计的测量误差建立误差校正模型,利用磁环境模拟器的磁场强度、温度及三轴磁强计的输出电压,对三轴磁强计进行温度建模,利用伪逆法求得三轴磁强计的标定系数,再利用标定系数和零位电压对温度进行线性拟合,可实现三轴磁强计测量的温度补偿。在温度可变的磁环境模拟器中采用校正方法对三轴磁强计进行测试,结果显示该校正方法具有很好的实用性。

Measurement of the magnetic field intensity is required for micro-satellite to damp and attitude control.The measurement errors because of change of the temperature would reduce the measurement precision of the three-axis magnetometer,so the measurement errors need to be calibrated.In this paper,an error calibration method of three-axis magnetometer measurement is proposed,and the error calibration model is established based on measurement error analysis.According to the magnetic field intensity and temperature of the magnetic simulator and the output voltage of the three-axis magnetometer,the temperature model of three-axis magnetometer is set up.The calibration coefficient is achieved by pseudo-inverse method,and the relationship between calibration coefficient and temperature,the relationship between zero-point voltage are fitted with linear method,then the measurement precision of the three-axis magnetometer could be compensated by temperature.The three-axis magnetometer is calibrated and tested in a magnetic simulator in which the temperature can change.The results verify the correctness and effective-ness of the calibration method proposed in the paper.