Measurement method of echo reduction in acoustic overlay based on multi-channel space-time inverse filtering technology

An acoustic covering layer and echo reduction technology, applied in the direction of using sonic/ultrasonic/infrasonic waves to analyze solids, etc., can solve the problems of increased measurement error, measurement signal reverberation interference, inability to form a free field environment, etc., to reduce the impact, eliminate Measure the effect of the signal, the effect of increasing the spatial resolution

Inactive Publication Date: 2018-02-23
ZHEJIANG UNIV
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Problems solved by technology

In the case of low frequencies, since the sound-absorbing materials around the measurement environment cannot completely absorb the sound waves, a free-field environment cannot be formed, and the measurement signal is severely interfered by reverberation, resulting in increased measurement errors

Method used

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  • Measurement method of echo reduction in acoustic overlay based on multi-channel space-time inverse filtering technology
  • Measurement method of echo reduction in acoustic overlay based on multi-channel space-time inverse filtering technology
  • Measurement method of echo reduction in acoustic overlay based on multi-channel space-time inverse filtering technology

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Embodiment Construction

[0020] The present invention will be further described below in conjunction with the drawings.

[0021] Reference Figure 1 ~ Figure 2 , An acoustic overlay echo reduction measurement method based on multi-channel space-time inverse filtering technology, used to measure the echo reduction of large samples of acoustic overlays in a limited space. The technical scheme of the whole measurement method is as follows:

[0022] 1) Generate single-channel space-time inverse filtered transmission signal

[0023] 11) First, use the least square algorithm to estimate the channel response. The time domain transfer function of the underwater acoustic channel can be expressed by the following formula

[0024]

[0025] Where δ(·) represents the Dirac function, which is equal to zero at points other than zero, t represents the time series, M represents the total number of multipaths, a i , F i , Τ i They are the fading factor, Doppler frequency and multipath delay of the i-th path signal;

[0026] Ac...

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Abstract

A method for measuring acoustic overlay echo reduction based on multi-channel space-time inverse filtering technology, comprising the following steps: 1) generation of single-channel space-time inverse filter transmission signal; 2) generation of multi-channel space-time inverse filter transmission signal; 3 ) Acquisition of sample echo signal and incident signal; 4) Calculation of echo reduction measurement value. Through the inversion of the circuit channel and the underwater acoustic channel and the synchronous transmission of multi-channel inversion signals, the present invention can realize the space focusing of the measurement signal and the time-domain pulse compression, so as to suppress the reverberation, separate the direct wave and the multiple echoes of the multi-layer sample the goal of.

Description

Technical field [0001] Underwater acoustic coating is a widely used and important underwater component in underwater acoustic engineering. In order to evaluate the echo reduction performance of acoustic coating samples, the echo reduction measurement of large samples under laboratory conditions is an important method , The present invention relates to a method for measuring the echo reduction of a large sample of an underwater acoustic covering layer. Background technique [0002] The concept of acoustic covering layer was proposed in 2010. It refers to the special functional acoustic materials and structures laid on underwater components, which are mainly composed of anechoic tiles, sound insulation tiles, vibration suppression tiles, decoupling tiles, array silencers, etc., which have different acoustic functions Acoustic protection system composed of a series of products. On the one hand, the acoustic covering layer can absorb active detection sound waves and reduce the acous...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01N29/04
Inventor 李建龙肖甫李素旋
Owner ZHEJIANG UNIV
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