State Feedback Self-Excited Fluxgate Sensor

Abstract

The invention discloses a state feedback type self-excitation fluxgate sensor which is configured such that three completely same fluxgate sensors are coupled through one-way ring topology and an output and hysteresis shaping circuit is connected to a counting display circuit. The amplitude and frequency of self-excitation of a sensor is regulated through state feedback, and the size of a to-be-tested magnetic field is determined through the detection within a time domain and the calculation of time difference of a magnetic core at a positive saturated state and a negative saturated sate, so that the detection of super-high sensitivity of the magnetic field is realized. Compared with prior art, the properties of the sensor is not prone to influence by stability and noise of an excitation signal generation apparatus, increases sensitivity and resolution in detecting the magnetic field. Compared with cascade magnetic flux, the sensor achieves the regulation of the sensor sensitivity through state feedback, and adopts a control algorithm to implement detection of the super-high sensitivity of the magnetic field. The sensor uses a time difference detection method to conduct detection on the magnetic field, achieves output and display of digital quantity, and provides basis for digitalized magnetic measurement of the fluxgate sensor.

Description

Technical field: [0001] The invention relates to a fluxgate sensor, in particular to a fluxgate sensor which does not need an external excitation signal. Background technique: [0002] The basic principle of the fluxgate sensor is Faraday's law of electromagnetic induction, which uses the hysteresis saturation characteristics of the magnetic core to convert the magnetic signal into an electrical signal for measurement. The fluxgate sensor has the advantages of high resolution, large measurement range and small residual magnetism error, and is a kind of weak magnetic measurement sensor with good comprehensive performance. [0003] Most of the existing fluxgate sensor products calculate the size of the measured magnetic field by detecting the even harmonics of the output signal. Their sensitivity and resolution are restricted by the noise of the probe. Generally, differential structure probes, high-precision current excitation and improved Optimizing the detection scheme and ...

AI Technical Summary

Problems solved by technology

By optimizing the probe structure and applying the time difference detection method, although the influence of the odd harmonic noise in the output signal of the fluxgate probe on the performance of the fluxgate sensor can be weakened, it depends on the external excitation signal to work normally, and is affected by the excitation signal. The stability of the generating device itself and the influence of noise are not conducive to the accurate detection of weak magnetic fields

[0004] US7420366B1 "Coupled nonlinear sensor system" and US7528606B1 "Coupled nonlinear sensor system for sensing a time-dependent target signal and method of assembling the system" disclose a self-excited cascaded flux through unidirectional annular coupling between fluxgates Door sensor, but once the sensor parameters are determined, the performance parameters such as the sensitivity of the sensor will be fixed, which is not conducive to ultra-high sensitivity detection and real-time detection of weak magnetic fields

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