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CN-122016033-A - Self-adaptive compressed sensing sound field measurement system and method

CN122016033ACN 122016033 ACN122016033 ACN 122016033ACN-122016033-A

Abstract

The invention discloses a self-adaptive compressed sensing sound field measurement system and a method, which belong to the technical field of sound field measurement, wherein the system comprises a hydrophone group, a plurality of hydrophones, a plurality of ultrasonic sensors and a plurality of ultrasonic sensors, wherein the hydrophones are used for step scanning of a sound field area; the device comprises a three-dimensional scanning positioning assembly, a signal acquisition unit and a control and processing unit, wherein the control and processing unit is used for processing voltage signals of a hydrophone. The invention concentrates most of measurement resources in the effective information area of the sound field through the self-adaptive strategy, the measurement resources are distributed in a self-adaptive way according to the information quantity, invalid sampling in a silent or low sound pressure area is avoided, the sampling point number can be reduced by more than one order of magnitude compared with the traditional dense scanning method, the iterative threshold value decrementing and local subdivision strategy is suitable for different sound beam forms, the method has good universality and expandability, complicated array hydrophones or encoding masks are not required to be developed, the method can be realized only by replacing hydrophones with different sizes and combining a mature scanning control system, the cost is low, the popularization is easy, and the hardware realization is simple and reliable.

Inventors

  • DONG PING
  • ZHAO WEI
  • WU YUN
  • LU QIANGBING
  • LU MINGHUI

Assignees

  • 江苏省计量科学研究院(江苏省能源计量数据中心)

Dates

Publication Date
20260512
Application Date
20260209

Claims (7)

  1. 1. An adaptive compressed perceived sound field measurement system, comprising: The hydrophone group comprises a plurality of hydrophones with different spatial resolutions r 1 ,r 2 ,r 3 ,r i ,.....,r n , which are named as H 1 hydrophone, H 2 hydrophone, H 3 hydrophone and H i hydrophone, wherein the H n hydrophone is used for step scanning a sound field area; the three-dimensional scanning positioning assembly is used for being connected with the hydrophone and driving the hydrophone to move; The signal acquisition unit comprises a preamplifier and a high-speed digitizer and is used for acquiring and recording voltage signals of the hydrophone; The control and processing unit is connected with the three-dimensional scanning positioning assembly and the signal acquisition unit and is used for processing the voltage signal of the hydrophone.
  2. 2. The adaptive compressed sensing sound field measurement system of claim 1, wherein the spatial resolution of the plurality of hydrophones is in the form of an equal-ratio array, the scaling factor is beta, Beta is a positive integer, and beta is more than or equal to 2 and less than or equal to 4.
  3. 3. An adaptive compressed sensing sound field measurement method, using the adaptive compressed sensing sound field measurement system according to any one of claims 1 to 2, comprising the steps of: S1, carrying out surface scanning measurement on the whole target scanning area by using an H 1 hydrophone through a first step St 1 to obtain a first sound field distribution map SF 1 , wherein the number of pixel points is assumed to be M multiplied by N; S2, carrying out wavelet transformation on the first sound field distribution map SF 1 data obtained in the S1 to obtain a first scale coefficient and a first detail coefficient, judging salient pixel points in the first sound field distribution map SF 1 according to a preset first threshold thr 1 , carrying out space subdivision on the area where the salient pixel points are located according to beta multiplied by beta, and marking all subdivided first space points to be detected; S3, replacing the H 1 hydrophone with the H 2 hydrophone, carrying out surface scanning measurement on the first space point to be measured in the S2 by using a second step St 2 , and fusing the measured data with a first sound field distribution map SF 1 to obtain a second sound field distribution map SF 2 , wherein the number of pixel points is betaM multiplied by betaN; S4, carrying out wavelet transformation on the fused second sound field distribution diagram SF 2 again to obtain a second scale coefficient and a second detail coefficient, judging salient pixel points in the second sound field distribution diagram SF 2 according to a second threshold thr 2 , carrying out space subdivision on the area where the salient pixel points are located according to beta multiplied by beta, marking all the subdivided second space points to be detected, and carrying out scanning measurement; S5, similarly, obtaining an ith sound field distribution map SF i by using an H i hydrophone, carrying out wavelet transformation on the obtained ith sound field distribution map SF i data to obtain an ith scale coefficient and an ith detail coefficient, judging salient pixel points in the sound field distribution map according to a preset ith threshold thr i , carrying out space subdivision on a region where the salient pixel points are located according to beta multiplied by beta, marking all the subdivided ith space points to be detected, replacing the H i hydrophone with an H i+1 hydrophone with higher spatial resolution, carrying out surface scanning measurement on the ith space points to be detected by using an (i+1) step St i+1 , fusing the measured data with the ith sound field distribution map SFi to obtain an (i+1) sound field distribution map SF i+1 , fusing the measured data with the (N-1) th sound field distribution map SF n-1 after the test of the H n hydrophone with the highest spatial resolution is completed, and obtaining an nth sound field distribution map SF n , and fusing the measured data with the (n+1) sound field distribution map SFi with the pixel point SFi as beta n-1 M×β n- 1 N.
  4. 4. The method for measuring an adaptive compressed sensing sound field according to claim 3, wherein in S1, a two-dimensional scanning grid covering the whole sound field of the sound source to be measured is firstly planned, the H 1 hydrophone moves point by point according to the two-dimensional scanning grid, the first step St 1 of the H 1 hydrophone keeps consistent in the x-axis direction and the y-axis direction, And acquiring waveforms output by the H 1 hydrophone at each point, recording the peak-to-peak sound pressure or time waveform of the point, and obtaining a first sound field distribution diagram SF 1 after the completion.
  5. 5. The adaptive compressed sensing sound field measurement method according to claim 4, wherein S2 specifically comprises: Wavelet analysis, namely performing Haar-based wavelet transformation on a first sound field distribution map SF 1 to obtain a first scale coefficient and a first detail coefficient; And judging the salient regions, namely comparing the absolute values of the first scale coefficient and the first detail coefficient with a first threshold thr 1 respectively, and if any one item is larger than the first threshold thr 1 , indicating that the corresponding pixel point regions are salient, and marking the salient regions.
  6. 6. The method for measuring an adaptive compressed sensing sound field according to claim 5, wherein the step S3 specifically comprises replacing the H 1 hydrophone with a H 2 hydrophone, wherein the spatial resolution of the H2 hydrophone is higher than that of the H1 hydrophone, performing surface scanning measurement on the first space point to be measured in the step S2 by using a second step St 2 , and keeping the second step St 2 of the H 2 hydrophone consistent in the x-axis and y-axis directions, st 2 = value And/beta, fusing the measured data with the first sound field distribution map SF 1 to obtain a second sound field distribution map SF 2 .
  7. 7. A method of adaptive compressed sensing sound field measurement according to claim 3, wherein the third step St 3 in S4 is kept consistent in the x-axis and y-axis directions, st 3 = And/β, wherein the (i+1) th step St i+1 in S5 is consistent in the x-axis and y-axis directions, st i+1 = /β。

Description

Self-adaptive compressed sensing sound field measurement system and method Technical Field The invention belongs to the technical field of sound field measurement, and particularly relates to a self-adaptive compressed sensing sound field measurement system and method. Background Sound field measurement is a key technique for evaluating and calibrating the performance of various sound source devices. In the fields of medical ultrasound, industrial nondestructive testing, underwater sound detection and the like, accurate acquisition of spatial sound pressure distribution is important to ensure the effectiveness, safety and reliability of equipment. Traditional acoustic field measurement methods rely primarily on a single point hydrophone (e.g., a needle hydrophone) performing a dense step scan in three dimensions. This method follows the nyquist sampling theorem and to ensure that sound field details (e.g., sharp focus, high gradient sidelobes) are not missed, the scan step size typically needs to be set to 1/3 or less of the intended beam diameter. For example, for a transducer with a frequency of 5MHz, the wavelength in water is about 0.3mm, and the lateral scan step size is often set to 0.1 mm or less to ensure accuracy. This point-by-point scanning approach results in a large number of sample points, making the entire measurement process extremely time-consuming, possibly up to hours or even days. Inefficiency has become a major bottleneck in the widespread use of high-precision sound field measurement techniques. In recent years, the theory of compressed sensing (Compressed Sensing, CS) has provided a new idea for breaking through this bottleneck. This theory states that for signals that are sparse or compressible over a certain transform domain (e.g. fourier transform, wavelet transform), the original signal can be perfectly reconstructed by a small number of non-adaptive linear measurements well below the nyquist sampling theorem requirement. Research and engineering applications have introduced CS into the field of acoustic imaging to reduce the sampling rate. However, applying CS to sound field measurements faces unique challenges: inefficiency of non-adaptive sampling traditional non-adaptive CS (e.g. random sampling) has a fixed measurement matrix and cannot be dynamically adjusted according to the characteristics of the sound field itself. The acoustic field energy is typically highly concentrated (e.g., focal region), and non-adaptive sampling wastes significant amounts of measurement resources in irrelevant areas of silence or low sound pressure. The stationarity of the hydrophone spatial response-a single hydrophone has its fixed effective receiving area and frequency response. The small-size hydrophone can ensure the spatial resolution, but has lower receiving sensitivity and poor signal-to-noise ratio in a low sound pressure area, and the large-size hydrophone can improve the signal-to-noise ratio, but can blur details due to the spatial average effect and lose the detection capability of a sound field fine structure. This is a contradiction to the difficulty of reconciling. Therefore, the prior art lacks a sound field measurement scheme capable of intelligently and adaptively allocating measurement resources and considering measurement efficiency, global signal-to-noise ratio and local resolution. Disclosure of Invention Aiming at the problems in the prior art, the technical problem to be solved by the invention is to provide a self-adaptive compressed sensing sound field measurement system and a self-adaptive compressed sensing sound field measurement method, which can obviously reduce the number of invalid sampling points, shorten the measurement time and improve the capability of considering the overall signal-to-noise ratio and the local spatial resolution on the premise of guaranteeing the resolvable key details such as a focus, a side lobe and the like. The technical scheme adopted by the invention is as follows in order to solve the technical problems: an adaptive compressed perceived sound field measurement system, comprising: The hydrophone group comprises a plurality of hydrophones with different spatial resolutions r 1,r2,r3,ri,.....,rn, which are named as H 1 hydrophone, H 2 hydrophone, H 3 hydrophone and H i hydrophone, wherein the H n hydrophone is used for step scanning a sound field area; the three-dimensional scanning positioning assembly is used for being connected with the hydrophone and driving the hydrophone to move; The signal acquisition unit comprises a preamplifier and a high-speed digitizer and is used for acquiring and recording voltage signals of the hydrophone; The control and processing unit is connected with the three-dimensional scanning positioning assembly and the signal acquisition unit and is used for processing the voltage signal of the hydrophone. Preferably, the spatial resolution of the plurality of hydrophones is in the form of an equal-ratio array,