FPGA-based flux gate micro signal detecting system and FPGA-based flux gate micro signal detecting method

Abstract

The invention provides an FPGA-based flux gate micro signal detecting system and an FPGA-based flux gate micro signal detecting method. The FPGA-based flux gate micro signal detecting system comprises a detecting module, an output module and a processing module which is realized by FPGA, wherein the detecting module converts a flux gate signal to a digital signal and transmits the digital signal to the processing module. The processing module performs processing for obtaining a secondary harmonic signal and transmits the secondary harmonic signal to the output module. According to the FPGA-based flux gate micro signal detecting method, after power amplification is performed on a sine wave with frequency of f0 / 2, saturation activation is performed on the activation coil of a flux gate sensor for generating a flux gate signal with frequency of f0. After filtering and analog-to-digital conversion are performed on the flux gate signal, cross-correlation detection is performed on the obtained digital signal and two reference signals for obtaining a secondary harmonic signal, the amplitude and the phase of the secondary harmonic signal. Finally digital-to-analog conversion is performed on the secondary harmonic signal, and the obtained analog signal drives the load to operate. According to the FPGA-based flux gate micro signal detecting system and the FPGA-based flux gate micro signal detecting method, related operation is realized by means of the FPGA. The FPGA-based flux gate micro signal detecting system and the FPGA-based flux gate micro signal detecting method have advantages of effective hysteresis reduction in signal transmission, high noise inhibition capability, convenient signal processing, and high measurement accuracy. Furthermore the FPGA-based flux gate micro signal detecting system and the FPGA-based flux gate micro signal detecting method can detect nanovolt-grade weak signals.

Description

Technical field [0001] The invention relates to a technique in the field of weak magnetic field measurement and control, in particular to an FPGA-based fluxgate micro signal detection system and method. Background technique [0002] Fluxgate sensor is a sensor that measures magnetic field information, which is widely used in micro-magnetic measurement. The fluxgate phenomenon is a common electromagnetic induction phenomenon. When the core permeability changes with the intensity of the exciting magnetic field, the induced electric potential of the output coil will appear even harmonic components that change with the intensity of the ambient magnetic field. Since the output signal in the induction coil of the fluxgate sensor is very weak and is often overwhelmed by noise signals, it is very difficult to extract useful second harmonic signals. [0003] Among the existing weak signal detection methods, the analog lock-in amplifier is a widely used detection method. However, because it...

AI Technical Summary

Problems solved by technology

Since the output signal in the induction coil of the fluxgate sensor is very weak, it is often submerged by the noise signal, and it is very difficult to extract the useful second harmonic signal

[0003] Among the existing weak signal detection methods, the analog lock-in amplifier is a widely used detection method, but because it is implemented by an analog circuit, it will introduce a lot of noise due to the influence of the characteristics of the electronic device, and is easily affected by temperature drift. impact, and the integration time of the associated detector is limited, resulting in limited detection accuracy

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