Superconducting magnetic compensation device and method based on predistortion

Abstract

The invention relates to a superconducting magnetic compensation device and method based on predistortion. The superconducting magnetic compensation device based on predistortion is characterized in that the device is composed of a reference magnetic sensor, a magnetic compensation circuit and a compensation coil, the reference magnetic sensor is used for measuring magnetic field signals of an area to be compensated, the magnetic compensation circuit is used for extracting signals of a frequency band to be compensated from the magnetic field signals measured by the reference magnetic sensor, and then the magnetic field of the specific area is compensated through the compensation coil. The compensation method is characterized in that denoising or threshold value judging digital signal processing is conducted in a controller after the measurement value of the external reference magnetic sensor is obtained through an analog-digital converter firstly, then predistortion is conducted selectively on an input signal of an SQUID device by means of a coil, with a feedback factor dozens of times higher than that of the SQUID device, driven by a power amplifier and a feedback resistor through a digital-analog converter, and finally sampling is conducted on output signals of a magnetic flow locking ring and the power amplifier through a synchronous data acquiring device. The superconducting magnetic compensation device is simple in structure, small in size, high in stability and suitable for being used during exercise or in outdoor environments.

Description

technical field [0001] The present invention relates to a magnetic compensation device and method for a superconducting magnetic sensor, in particular to a device for realizing magnetic compensation by means of pre-distortion on the basis of a traditional Flux-Locked Loop (FLL: Flux-Locked Loop) readout circuit and methods. It belongs to the field of magnetic compensation. Background technique [0002] The superconducting magnetic sensor composed of superconducting quantum interferometer (SQUID: Superconducting QUantum Interference Device) is currently the most sensitive magnetic sensor known. It has been used in many applications in magnetically shielded rooms and static working environments. In the moving platform, the magnetic field signal introduced by factors such as external strong magnetic field changes or cutting the earth's magnetic force lines can easily cause the baseline drift or even overflow of the highly sensitive SQUID readout circuit to fail to work normall...

AI Technical Summary

Problems solved by technology

Although this method can suppress the influence of environmental field disturbance on SQUID magnetic measurement without affecting the measurement of weak signals, its stability is difficult to control because of the use of a second-order negative feedback circuit, and is affected by the SQUID's Feedback coil (feedback coil) The influence of the feedback coefficient, the magnetic field strength and frequency range that can be compensated are limited

[0006] In summary, when the existing magnetic compensation methods work in sports and field environments, either there are applicability and reliability problems, or the compensation range or background noise is not ideal, which greatly affects the application of superconducting magnetic sensors in industry and scientific research. Wide application and promotion in the medical field

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