Fluxgate Sensor And Error Correction Technology

Fluxgate sensor is a sort of transformer structure which modulates magnetic signal intoelectric signal under the stimulus of periodic alternating current. As it has several advantages likesmall volume, simple structure and high resolution, the fluxgate sensor is widely used in manyfields such as scientific researches, national defense construction, industrial production, daily lifeand so on.With reference of domestic and foreign academic articles about fluxgate sensor and review oftheir development and application, this paper analyzes operating principles of fluxgate sensorswith different probe structures and makes analysis and comparisons with current frequently-usedfluxgate signal detection methods, including pulse amplitude method, pulse width method andmethod of second harmonics. On this basis, the fluxgate sensor model machine with the structureof double magnetic core based on the method of second harmonics reaches actual measurementof0.2nT in resolution, and the linearity is superior to15ppm through improving probe structureand optimizing detector circuit.Actually fluxgate sensor’s three axes are not orthogonal strictly, and their sensitivity and otherelectrical properties are impossible identical. Besides, zero wander, remainder magnetic fieldinside the sensor and other factors result in error between measured value from the sensor andactual value. Therefore, the paper puts forward the method of elliptical least square estimation toamend the measurement error. And the error correction test indicates that the triaxial fluxgatesensor’s diversionary error with different postures reduces from433nT to below29nT. Theobvious reduction of the difference of reading at the opposite orientation shows that the method,to some extent, can effectively eliminate measured error of the triaxial fluxgate sensor.In the end, the paper makes summary and conclusion of deficiencies in the process of researchand comes up with the direction of further research.