微型四旋翼无人机磁测系统误差的两步校准法研究

用于地磁测量的MEMS三轴磁阻传感器越来越普遍的应用到无人机上进行姿态测量，为提高磁测系统的测量精度需要对传感器误差进行分析和补偿。现采用了一种两步校准法，即首先利用基于最小二乘的椭球假设拟合法对三轴矢量磁传感器的零偏、灵敏度与不正交误差进行标定补偿，目的是得到准确正交的传感器坐标系；利用四位置法对标定后传感器坐标系与测量系统坐标系之间的安装误差进行校准，从而得到磁测系统坐标系下的准确测量数据。无磁转台实验表明：经两步法后测量的磁场模值误差均值由校准前的2900nT降低为900nT，校准效果明显；测量系统单轴（Z轴）的误差均值由2736nT降低为49nT，有效的验证了安装误差校准的正确性。通过实验数据比较得出此方法优于传统的摇摆法，实际操作简单，不需要高精度辅助设备，能够有效的应用于无人机姿态测量系统校准，提高姿态角解算精度。

Two step calibration method of Magnetic measurement system error for Miniature four rotor UAV

Used in geomagnetic measurement of MEMS applications of three-axis magnetic resistance sensor is becoming more common on the unmanned aerial vehicle (UAV) attitude measurement, to improve the accuracy of measurement of magnetic survey system needs analysis and compensation of sensor error. Now used a two-step calibration method, namely the first use based on the assumption of ellipsoid least-square fitting of three axis vector magnetic sensor$#@%%$s zero, sensitivity and the orthogonal error calibration and compensation purpose is to get accurate sensors of orthogonal coordinate system; After four location method is then used to calibrate sensor coordinate system and measurement system calibration, the installation error between to get the accurate measurement data of magnetic survey system coordinates. Non-magnetic turntable experiment showed that after two-step measurement module and error of the mean values of magnetic field by the calibration before 2900 nT reduced to 900 nT, calibration effect is obvious; The error of the measurement system for single axis (the Z axis) mean by 2736 nT reduced to 49 nT, effective verify the validity of the installation error calibration. By comparing the experimental data it is concluded that this method is superior to the traditional swing, practical operation is simple, do not need high precision auxiliary equipment, can be effectively applied to UAV attitude measurement system calibration, improve the attitude Angle calculating precision.