Amplitude-phase compensation method of magneto-electricity type low-frequency vibration sensor

Abstract

The invention discloses an amplitude-phase compensation method of a magneto-electricity type low-frequency vibration sensor. The method comprises: obtaining a pre-calibrated amplitude-frequency characteristic and a pre-calibrated phase-frequency characteristic of a low-frequency vibration sensor and carrying out discrete sampling on an output signal of the low-frequency vibration sensor; carrying out three-times Hermite interpolation calculation on the pre-calibrated amplitude-frequency characteristic and the pre-calibrated phase-frequency characteristic; carrying out fast Fourier transform on a sampling result of the low-frequency vibration sensor and calculating an magnitude spectrum and a phase spectrum; compensating the magnitude spectrum and the phase spectrum to obtain an magnitude spectrum and a phase spectrum after compensation; and carrying out inverse fourier transform on the magnitude spectrum and the phase spectrum after compensation to obtain a real vibration signal after compensation correction. According to the amplitude-phase compensation method disclosed by the invention, signal distortion caused by own characteristics of the sensor can be corrected; ad real and reliable original data can be provided for a structural vibration analysis. The amplitude-phase compensation method is suitable for amplitude-phase compensation of the magneto-electricity type low-frequency vibration sensor.

Description

technical field [0001] The invention belongs to the technical field of measurement, and more specifically relates to a method for amplitude and phase compensation of a magnetoelectric low-frequency vibration sensor. Background technique [0002] In the existing low-frequency vibration sensor, the front-end magnetoelectric vibration pickup converts the vibration speed signal into an electrical signal through the cutting of the electromagnetic coil by the magnet vibration, and the back-end integral compensation circuit compensates the vibration speed component and outputs it as a speed signal or integrates it as The vibration displacement signal is output. Due to the inertial pendulum principle of the vibrator, the amplitude of the signal smaller than its natural frequency will drop sharply. Therefore, the back-end integral compensation circuit needs to perform low-frequency compensation for the signal of the vibrator smaller than the natural frequency to ensure The consistenc...

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Problems solved by technology

[0002] In the existing low-frequency vibration sensor, the front-end magnetoelectric vibration pickup converts the vibration speed signal into an electrical signal through the cutting of the electromagnetic coil by the magnet vibration, and the back-end integral compensation circuit compensates the vibration speed component and outputs it as a speed signal or integrates it as The vibration displacement signal is output. Due to the inertial pendulum principle of the vibrator, the amplitude of the signal smaller than its natural frequency will drop sharply. Therefore, the back-end integral compensation circuit needs to perform low-frequency compensation for the signal of the vibrator smaller than the natural frequency to ensure The consistency of the output signal, due to the amplitude-frequency characteristics of the low-frequency compensation circuit itself, will lead to the distortion of the amplitude and phase of the ultra-low frequency component of the final output electrical signal of the sensor, which in turn will cause distortion of the vibration signal picked up by the sensor, which cannot reflect the real vibration of the structure

[0003] Due to the complexity of the actual vibration of the structure, it is difficult for researchers to intuitively find that the signal collected by the sensor is actually a distorted signal. When performing various analyzes on the signal, the original signal collected was not preprocessed, and the analysis results It cannot truly reflect the vibration of the structure, so there is an urgent need for a signal processing method to correct the distortion signal collected by this magnetoelectric low-frequency vibration sensor

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