High Accuracy Acquisition of the Magnetic Heading Signal

The function of the fluxgate sensor in the aircraft navigation system is to calibrate the heading of gyro. Its magnetic heading signal is weak and anomalous synchro signal. Experimental results show that this signal cannot be measured directly and exactly by using SDC. This paper designs a negative feedback amplifying circuit which uses the servo amplifying setup and synchronizer equipment to convert the magnetic heading signal to the standard synchro signal. Meanwhile, we study and manufacture the SDC and DSC modules which integrate the multifunction based-on PC-104 bus synchro/digital converting card. In the practical operation, we adopt the above-mentioned scheme and calibrate the compass error by the software. The result demonstrates that the acquisition accuracy of magnetic heading signal reaches 0.1deg and meets the demands of the navigation accuracy.