一种十二位置不对北的磁罗盘标定方法

Twelve-position calibrating method without north reference for magnetic compass

由于磁阻传感器本身特性的差异和生产装配,给磁罗盘带来了零位、标度因数不一致和安装误差等因素。为此设计了一种十二位置不对北的标定方法,它完全依靠天向磁场,推导了三轴零位、标度因数和安装误差的公式;硬铁的影响可等价于三轴零位的改变,软铁的影响等价于三轴标度因数和安装误差的改变,采用十二位置不对北方法,标定得到在软硬铁影响下的三轴零位、标度因数和安装误差。实验显示:补偿后水平时航向角均方误差为0.2°,26°倾角时航向角均方误差为0.4°。

Among the many factors affecting the system errors of compass （i.e, bias, scale factor error and install alignment error, etc.）, one large contributor comes from the difference characteristics of magneto-resistive sensors during production and installation. A 12-position calibrating method without north reference for magnetic compass was developed. The equations of three-axis bias, scale factor error and install alignment error was deduced in the proposed method which is totally based on the magnetic field of up direction. The effect of hard iron distortion is equaled to the variation of three-axis bias. The effect of soft iron distortion is equaled to the variations of three-axis scale factor and install alignment. Three-axis bias, scale factor error and install alignment error with hard iron and soft iron effects were calibrated by the proposed 12-position calibrating method without using north reference for magnetic compass. And the experiment results demonstrate that the heading accuracy after compensation is 0.2° on horizontal plane, the heading accuracy after compensation is 0.4° for tilt angle of 26°.