Common mode noise suppression device and noise suppression method for time-difference type fluxgate sensor

Abstract

The invention relates to a common-mode noise inhibition device and method of a time difference type flux gate sensor. A detection circuit I and a reference circuit II are included, a resistor in the detection circuit I is replaced with a time difference type flux gate probe, and a digital signal collection circuit and a collection result thereof are obtained; and subtraction is carried out on the obtained collection result, and common-mode noise is removed from two paths of signals. Compared with a present signal processing circuit of the time difference type flux gate sensor, it is not required to change the structure of the signal processing circuit or flux gate probe, or use a complex algorithm, and common-mode noises of the time difference type flux gate sensor can be inhibited rapidly by only ensuring that the two circuits can realize synchronous real-time measurement. Noise, introduced by excitation current, of the time difference type flux gate sensor can be inhibited effectively, and the strict requirement for an excitation current signal generator can be reduced.

Description

Technical field: [0001] The invention relates to a common-mode noise suppression device of a time-difference fluxgate sensor, in particular to a device for improving sensor performance by using a bypass reference method. Background technique: [0002] Fluxgate sensors are widely used in the measurement of weak magnetic fields or DC magnetic fields because of their small size, high sensitivity, and good directionality. According to different detection principles, fluxgate sensors can be divided into even harmonic fluxgate sensors and time difference fluxgate sensors. The even-order harmonic fluxgate sensor measures in the frequency domain, and its output signal is easily affected by odd-order harmonics, while the time-difference-type fluxgate sensor measures in the time domain, which can compensate for the traditional even-order harmonic fluxgate sensor. The deficiency of the door sensor is based on the nonlinear hysteresis characteristic of the magnetic core, and the magnet...

AI Technical Summary

Problems solved by technology

[0003] According to its detection principle, the time-difference fluxgate sensor is easily affected by electronic circuit noise and excitation current noise in the time domain, which increases the fluctuation of the time difference between the positive and negative pulses output by the fluxgate probe and introduces noise to the sensor, thereby causing the sensor to be detected. The measurement error of the measured magnetic field is not conducive to the detection of the target magnetic field

[0004] CN103336252A discloses "Signal Detection Method of Hysteresis Time Difference Type Fluxgate Sensor", which adopts the method of curve fitting to fit the data near the positive and negative peaks of the time difference type fluxgate sensor output signal, and this method can avoid the threshold value from affecting the sensor output performance , but the implementation is complicated, and quantization errors will be introduced, and the sensor signal detection accuracy is affected by the fitting accuracy

(R.H.Koch, J.R.Rozen, Low-noise flux-gate magnetic-field sensors using ring-and rod-coregeometries, Applied Physics Letters, V78, 2001) By adjusting the magnetic core structure, the noise of the fluxgate sensor is reduced, but due to Due to the limitation of domestic magnetic core processing technology, it is difficult to realize

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