Design Of Magnetic Compass Sensor Based On CPLD

We provide a new design method of magnetic compass sensor which had the weaknessof complex structure and high price before. This kind of sensor which takes orthogonalfluxgate sensor as the sensing probe has simple structure, workability and moderate accuracy.In this paper, we design an orthogonal fluxgate sensor based on CPLD. The sensorwhose probe is made up of annular core that is twined orthogonal windings can measure themagnetic field; It is designed of CPLD digital circuit which changes the traditional layout ofanalog circuit and reduces the use of discrete components; Its final output is in the form ofpulse counting using the method of pulse filling. In the course of study, we have finished thedesign of hardware circuit, software, welding, hierarchical debugging and system leveldebugging, and performance experiment. The magnetic compass sensor is placed on thenon-magnetic turntable for horizontal test. Finally we analyze and classify the deviation andpropose the compensation method. The test results meet the design requirements.This kind of orthogonal fluxgate sensor whose measuring precision can reach3°and theresolution can reach1°can measure horizontal heading angle from0°~360°. It has simplecircuit structure, easy adjustable parameters, small volume, light weight, low powerconsumption, low cost and great application prospect and can meet the requirement of theperformance of horizontal directional navigation.