Low-frequency vector hydrophone based on eddy current thickness measurement

Abstract

The invention belongs to the technical field of vector hydrophones, and particularly relates to a low-frequency vector hydrophone based on eddy current thickness measurement. The measurement amount isdisplacement, the sensitivity is high at low frequency, the direct measurement amount of a sensor is thickness, a converter of the thickness and the displacement is a wedge-shaped metal film and canbe regarded as an amplifier, and the low-frequency sensitivity of the vector hydrophone is further improved. A sensitive element adopted by the invention is an eddy current sensor, is used for measuring two metal films which are opposite in positions and directions respectively, differential output is carried out, and the sensitivity of the vector hydrophone is improved, and the noise influence ofthe vector hydrophone is reduced. The displacement in the vertical direction is measured through the horizontally-installed sensor, the installation structure of the displacement type vector hydrophone is expanded, and a three-dimensional displacement vector hydrophone can be further manufactured through optimization.

Description

technical field [0001] The invention belongs to the technical field of vector hydrophones, in particular to a low-frequency vector hydrophone based on eddy current thickness measurement. Background technique [0002] Under the action of sound waves, the particle of the medium reciprocates around its equilibrium position, and its instantaneous position, vibration displacement and instantaneous velocity all change with time, so the vibration displacement or velocity of the particle can also be used to describe the sound field. Vector hydrophones can obtain vector information in the underwater sound field, including signals such as displacement, vibration velocity, acceleration, and sound pressure gradient of water particles. Today, the technology of vibration velocity, acceleration and sound pressure gradient vector hydrophones has matured and is widely used in various fields of underwater acoustics. However, the research on displacement vector hydrophones is still in its infa...

AI Technical Summary

Problems solved by technology

Today, the technology of vibration velocity, acceleration and sound pressure gradient vector hydrophones has matured and is widely used in various fields of underwater acoustics. However, the research on displacement vector hydrophones is still in its infancy. stage

[0003] The traditional acceleration vector hydrophone, as the frequency decreases, its sensitivity decreases by 6dB per octave, resulting in low frequency sensitivity of the acceleration vector hydrophone, which cannot meet the low-frequency sound measurement requirements; the velocity vector hydrophone The sensitivity of the displacement-type vector hydrophone does not change with the change of the frequency, and it is a constant value; the sensitivity of the displacement vector hydrophone decreases with the frequency, and the sensitivity increases by 6dB per octave, see the article Eddy-current non-inertial displacement sensing forunderwater infrared measurements. (Journal of the Acoustical Society of America 2011,129(6):254-259) and (Jia Zhifu. The characteristics and structural design of three-dimensional co-vibration spherical vector hydrophones. Applied Acoustics, 2001, 20(4 ): 15-20), so the sensitivity of the displacement vector hydrophone is relatively high at low frequencies

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