无磁转台的电子罗盘误差分离标定方法

Calibration method of electronic compass with error-separation based on non-magnetic turntable

采用3个分立的磁感式磁传感器和三轴加速度传感器制作了全数字输出电子罗盘;基于自制三轴旋转无磁转台提出了一种电子罗盘标误差分离标定方法。通过无磁转台获取磁传感器敏感轴非正交或未对准的参数和磁传感器输出特性曲线,磁传感器的灵敏度系数因子和偏置量。分别评价偏置、灵敏度系数不一致以及非正交或未对准对电子罗盘方位角精度的影响。实验结果表明:经过校准后,电子罗盘水平面内误差不超过0.22°,而俯仰角和翻滚角在60°内时,方位角最大误差约为0.4°,说明了标定方法的有效性。

Full digital electronic compass is developed by using magnetic-inductive sensors and acceleration sensors and the error-separation method based on non-magnetic three-axis rotation platform is presented to calibrate the magnetic compass. The parameters about misalignment and non-orthogonality of the sensor axes and the response curve of sensor output to earth magnetic intensity are obtained. Furtherly, the sensitivity of magnetometers and the bias from the offset and hard-iron interference are estimated according to the response curve. The independent effect of non-orthogonality and misalignment, bias and inconsistence in sensitivity on the beading error can be evaluated with the error-separation method, respectively. After calibration, the maximum heading error of magnetic compass is about 0.4° when both pitch angle and roll angle are in the range of 60°, indicating the error-separation method is effective and efficient to calibrate electronic compasses.