Real-time adjusting and optimizing system for working point of giant magneto-impedance sensor and giant magneto-impedance sensor

Abstract

The invention discloses a real-time adjusting and optimizing system for a working point of a giant magneto-impedance sensor. The system comprises a control unit, an excitation signal unit and a bias coil driving unit, the control unit is used for controlling the excitation signal unit to generate an excitation signal with adjustable frequency and amplitude, and the control unit is used for controlling the bias coil driving unit to generate a driving signal with an adjustable amplitude. The invention further discloses an adjusting and optimizing method. The adjusting and optimizing method comprises the following steps of S01, generating the excitation signal of which the frequency and the amplitude change according to a rule; or / and generating the driving signal of which the amplitude changes according to a rule; and S02, when the change rate of a response signal is reduced no matter whether the excitation signal or / and the driving signal is up-adjusted or down-adjusted, taking the excitation signal or / and the driving signal at the moment as a working parameter. The invention further discloses the giant magneto-impedance sensor which comprises an amorphous wire, a signal pickup coil, a bias coil and the adjusting and optimizing system. The system and the giant magneto-impedance sensor of the scheme both have the advantages of being high in automation degree, being able to be applied to different environments to improve sensitivity and the like.

Description

technical field [0001] The invention mainly relates to the technical field of giant magneto-impedance sensors, in particular to a system and method for real-time tuning of working points of giant magneto-impedance sensors and giant magneto-impedance sensors. Background technique [0002] For the magnetic field detection probe based on the giant magneto-impedance effect (GMI), its working performance is determined by various factors such as the size of the amorphous wire, the winding method of the signal pickup coil, the excitation signal of the amorphous wire and the setting of the bias magnetic field, and the external temperature and humidity. In practical application, since the hardware structure of a probe has been solidified, the method to achieve the optimal working point at this time is mainly to change the excitation signal of the amorphous wire and apply a bias magnetic field to the working environment of the amorphous wire. [0003] In the current design, the settin...

AI Technical Summary

Problems solved by technology

Although the circuit composed of this method is compact and compact, it is generally unable to make the amorphous wire reach the optimal working point, and when the external conditions change, it cannot make corresponding adjustments, making the working performance of the probe very unstable. In 2013, China In the patent "Bridge Resistance Giant Magnetoimpedance Effect Magnetic Field Sensor" applied by the Institute of Geophysics of the Earthquake Administration, an additional feedback coil is set in addition to the signal pickup coil and bias coil. By reversely connecting the output of the rear amplifier to the feedback coil, To a certain extent, the temperature stability and frequency response of the magnetic probe are enhanced

However, this kind of hardware-cured feedback loop can only slightly improve the stability and sensitivity of the probe, but cannot keep the probe at the optimal working point; Optimized control algorithm added to it

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