A method for automatically detecting the phase response consistency of a multi-channel hydrophone

Abstract

The present application relates to a kind of multi-channel hydrophone phase response consistency automated detection method, the following steps are executed using computer, step 1, single channel positive and negative phase opposite detection;Step 2, seek time delay matrix;Step 3, the consistency detection of each channel positive and negative orientation;Wherein, the specific operation of single channel positive and negative phase opposite detection of step 1 is as follows, step 1.1, sound source emits periodic T, the duty cycle of sinusoidal pulse signal is h, and the response waveform of the output of both sides of each channel positive and negative is recorded, for the i only hydrophone, record positive output signal p i,+ [n] and negative output signal p i,‑ [n], n is the sampling time sequence of digital signal.The present application avoids tedious manual detection, reduces the burden of workers;Greatly reduce the time required for detection, improve detection efficiency;Judgment standard quantization;Detection threshold can be adjusted according to test environment and condition.

Description

Technical fields:

[0001] This invention belongs to the field of hydrophone technology, specifically relating to an automated detection method for phase response consistency of multi-channel hydrophones. Background technology:

[0002] In the production process of multi-channel hydrophones, it is necessary to test indicators such as the phase consistency of the responses of each channel. Since the hydrophone is not fully encapsulated, this testing can only be performed in the air. Currently, this testing is done manually, which presents problems such as heavy worker workload, slow testing speed, and inconsistent testing standards.

[0003] Taking a certain type of multi-channel hydrophone as an example, the channels are arranged in a matrix on the panel. One panel contains A rows and B columns, totaling N = AB channels. Each channel has two outputs: a positive (+) and a negative (-). During wiring, the 2N outputs are connected in the order 1+, 1-, 2+, 2-, 3+, 3-, ... Before packaging, the phase consistency of the response of each channel needs to be tested and checked. Phase consistency includes the following two aspects:

[0004] 1. Positive and negative phases of a single channel are opposite: For each channel, if the waveforms of the positive and negative outputs have the same amplitude and opposite phase, it is considered qualified; otherwise, it is considered unqualified.

[0005] 2. Consistency of positive and negative polarity orientation among channels: If the positive polarity orientation of each channel is consistent, that is, the orientation of each output satisfies the condition of positive and negative adjacent (+, -, +, -, +, -, ...), then it is considered qualified; otherwise, it is considered unqualified (e.g., +, -, -, +, +, -, ...).

[0006] In the current production process, this detection mainly relies on manual sound generation and visual judgment of waveforms, which suffers from low production efficiency, inconsistent judgment standards, and heavy workload for workers. Using computer programs for detection could potentially solve these problems. Summary of the Invention:

[0007] The technical problem to be solved by the present invention is to provide an automated detection method for the phase response consistency of multi-channel hydrophones. This method avoids tedious manual inspection, reduces the burden on workers, greatly reduces the time required for inspection, and improves inspection efficiency.

[0008] The technical solution of this invention is to provide an automated method for detecting the phase response consistency of a multi-channel hydrophone, which utilizes a computer to perform the following steps:

[0009] Step 1: Detection of opposite phases between the positive and negative electrodes of a single channel;

[0010] Step 2: Calculate the time delay matrix;

[0011] Step 3: Detect the consistency of positive and negative electrode orientation across all channels; among which,

[0012] The specific operation for detecting the opposite phase of the positive and negative poles in a single channel in step 1 is as follows:

[0013] Step 1.1: The sound source emits a sinusoidal pulse signal with a period of T and a duty cycle of h, and records the response waveforms of the positive and negative outputs of each channel. For the i-th hydrophone, record the positive output signal p. i,+ [n] and negative output signal p i,- [n], where n is the sampling timing of the digital signal;

[0014] Step 1.2: For the i-th channel, calculate the correlation coefficient r between the positive and negative output signals. i =r{p i,+ [n],p i,- The correlation coefficient is defined as [n]}.

[0015]

[0016] r obtained from the above formula i ∈[-1,1];

[0017] Step 1.3, if the positive and negative poles are out of phase, then r i =-1; if the positive and negative poles are in phase, then r i =1, the standard for judging whether a hydrophone is qualified is set as: r i <th1, where th1 is the detection threshold;

[0018] The specific steps for calculating the time delay matrix in step 2 are as follows:

[0019] Step 2.1: The sound source emits a sinusoidal pulse signal with a period of T and a duty cycle of h, and records the response waveform of each channel. For the i-th hydrophone, record the positive output signal p. i,+ [n] and negative output signal p i,- [n], where n is the sampling timing of the digital signal;

[0020] Step 2.2: Using the positive output of channel 1 as the standard, calculate the cross-correlation coefficients of the positive outputs of the remaining (N-1) channels relative to channel 1. Specifically, for any -Tf s / 2<m<Tf s / 2, T is the period of the sinusoidal pulse signal, f s The sampling rate is used to calculate the cross-correlation coefficient r according to formula (1). 1i [m]=r{p 1,+ [n],p i,+ [n+m]};

[0021] Step 2.3: Find the maximum value of the cross-correlation coefficient. The corresponding time delay is denoted as M. 1i M 1i It is the time delay for the signal to arrive at the two channels (the first and the i-th);

[0022] Step 2.4: Using the positive outputs of the 2nd, 3rd, ..., Nth channels as the standard, repeat steps 1.2 to 1.3 to obtain an N x N cross-correlation matrix R = [R ij ] N×N And the time delay matrix M = [M ij ] N×N ;

[0023] The specific steps for checking the consistency of positive and negative pole orientation between channels in step 3 are as follows.

[0024] Step 3.1: Based on the cross-correlation matrix R = [R] obtained in Step 2 ij ] N×N And the time delay matrix M = [M ij ] N×N If R ij If the correlation coefficient is greater than th2, then the orientation is considered to be the same; otherwise, the orientation is considered to be opposite. Here, th2 is the threshold for the correlation coefficient.

[0025] Step 3.2: Considering the presence of reverberation and noise interference in the environment, th2 can be adjusted during actual measurement (e.g., th = 0.7 can be set). Furthermore, since the accuracy of delay calculation is not always 100%, a detection pass rate threshold η can be set. For the i-th channel, if R... i1 ,R i2 ,…R iN Among a total of N cross-correlation coefficients, there are proportions greater than η that satisfy R. in If the value is greater than th2, then the orientation is considered the same; otherwise, the orientation is considered opposite.

[0026] This invention discloses a computer program method for detecting the manufacturing process of a multi-channel hydrophone, specifically detecting the correctness of the channel sequence. The detection method involves a sound source emitting an excitation signal, recording the response of each channel, and determining the correctness of the channel sequence based on the response waveforms. Furthermore, the signal emitted by the sound source should be a sinusoidal pulse signal with a fixed duty cycle; otherwise, it may affect the accuracy of time delay calculation, leading to incorrect judgment. By calculating the cross-correlation coefficients and time delay matrices of each channel relative to each other, and setting a detection pass rate threshold, the program becomes less sensitive to misjudgments in a single measurement, thus improving the accuracy of the judgment.

[0027] As a preferred option, the detection threshold th1 and the correlation coefficient determination threshold th2 can be adjusted according to the experimental environment.

[0028] Preferably, the detection threshold th1 is any value between -1 and -0.9.

[0029] Preferably, the correlation coefficient determination threshold th2 is any value between 0.6 and 0.9.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] This invention avoids tedious manual inspection, reducing the burden on workers; it greatly reduces the time required for inspection and improves inspection efficiency; the judgment criteria are quantified; and the inspection threshold can be adjusted according to the test environment and conditions. Attached image description:

[0032] Figure 1 This is a block diagram for detecting the opposite phase of the positive and negative poles of a single channel in step 1 of the present invention.

[0033] Figure 2 The block diagram for calculating the time delay matrix in step 2 of this invention is shown.

[0034] Figure 3 This is a block diagram for detecting the consistency of positive and negative pole orientation between channels in step 3 of the present invention. Detailed implementation method:

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0036] An automated method for detecting the phase response consistency of a multi-channel hydrophone involves using a computer to perform the following steps.

[0037] Step 1: Detection of opposite phases between the positive and negative electrodes of a single channel;

[0038] Step 2: Calculate the time delay matrix;

[0039] Step 3: Detect the consistency of positive and negative electrode orientation across all channels; among which,

[0040] like Figure 1 The specific operation for detecting the opposite phase of the positive and negative poles of a single channel in step 1 is as follows:

[0041] Step 1.1: The sound source emits a sinusoidal pulse signal with a period of T and a duty cycle of h, and records the response waveforms of the positive and negative outputs of each channel. For the i-th hydrophone, record the positive output signal p. i,+ [n] and negative output signal p i,- [n], where n is the sampling timing of the digital signal;

[0042] Step 1.2: For the i-th channel, calculate the correlation coefficient r between the positive and negative output signals. i =r{p i,+ [n],p i,-The correlation coefficient is defined as [n]}.

[0043]

[0044] r obtained from the above formula i ∈[-1,1];

[0045] Step 1.3, if the positive and negative poles are out of phase, then r i =-1; if the positive and negative poles are in phase, then r i =1, the standard for judging whether a hydrophone is qualified is set as: r i <th1, where th1 is the detection threshold and is adjustable. Typically, the detection threshold th1 is any value between -1 and -0.9. In this embodiment, it is -0.95.

[0046] like Figure 2 ,

[0047] The specific steps for calculating the time delay matrix in step 2 are as follows:

[0048] Step 2.1: The sound source emits a sinusoidal pulse signal with a period of T and a duty cycle of h, and records the response waveform of each channel. For the i-th hydrophone, record the positive output signal p. i,+ [n] and negative output signal p i,- [n], where n is the sampling timing of the digital signal;

[0049] Step 2.2: Using the positive output of channel 1 as the standard, calculate the cross-correlation coefficients of the positive outputs of the remaining (N-1) channels relative to channel 1. Specifically, for any -Tf s / 2<m<Tf s / 2, T is the period of the sinusoidal pulse signal, f s The sampling rate is used to calculate the cross-correlation coefficient r according to formula (1). 1i [m]=r{p 1,+ [n],p i,+ [n+m]};

[0050] Step 2.3: Find the maximum value of the cross-correlation coefficient. The corresponding time delay is denoted as M. 1i M 1i It is the time delay for the signal to arrive at the two channels (the first and the i-th);

[0051] Step 2.4: Using the positive outputs of the 2nd, 3rd, ..., Nth channels as the standard, repeat steps 1.2 to 1.3 to obtain an N x N cross-correlation matrix R = [R ij ] N×N And the time delay matrix M = [M ij ] N×N .

[0052] like Figure 3 The specific steps for checking the consistency of the positive and negative pole orientations between channels in step 3 are as follows.

[0053] Step 3.1: Based on the cross-correlation matrix R = [R] obtained in Step 2 ij ] N×N And the time delay matrix M = [M ij ] N×N If R ij If the value is greater than th2, the orientation is determined to be the same; otherwise, the orientation is determined to be opposite. Here, th2 is the correlation coefficient determination threshold and is adjustable. The correlation coefficient determination threshold th2 is any value between 0.6 and 0.9; in this embodiment, it is 0.7.

[0054] Step 3.2: Considering the presence of reverberation and noise interference in the environment, th2 is adjustable during actual measurement. Furthermore, since the accuracy of delay calculation is not always 100%, a detection pass rate threshold η can be set. For the i-th channel, if R... i1 ,R i2 ,…R iN Among a total of N cross-correlation coefficients, there are proportions greater than η that satisfy R. in If the value is greater than th2, then the orientation is considered the same; otherwise, the orientation is considered opposite.

[0055] This invention avoids tedious manual inspection, reducing the burden on workers; it greatly reduces the time required for inspection and improves inspection efficiency; the judgment criteria are quantified; and the inspection threshold can be adjusted according to the test environment and conditions.

[0056] The above description only illustrates preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. Any equivalent procedural modifications made using this specification are included within the patent protection scope of this invention.

Claims

1. An automated method for detecting the phase response consistency of a multi-channel hydrophone, characterized in that: Includes the following steps, Step 1: Detection of opposite phases between the positive and negative electrodes of a single channel; Step 2, calculate the time delay matrix; Step 3: Detect the consistency of positive and negative electrode orientation across all channels; among which, The specific operation for detecting the opposite phase of the positive and negative poles in a single channel in step 1 is as follows: Step 1.1: The sound source emits a sinusoidal pulse signal with a period of T and a duty cycle of h, and records the response waveforms of the positive and negative outputs of each channel. For the i-th hydrophone, record the positive output signal p. i,+ [n] and negative output signal p i,- [n], where n is the sampling timing of the digital signal; Step 1.2: For the i-th channel, calculate the correlation coefficient r between the positive and negative output signals. i =r{p i,+ [n],p i,- The correlation coefficient is defined as [n]}. r obtained from the above formula i ∈[-1,1]; Step 1.3, if the positive and negative poles are out of phase, then r i =-1; If the positive and negative poles are in phase, then r i =1, the standard for judging whether a hydrophone is qualified is set as: r i <th1, where th1 is the detection threshold; The specific steps for calculating the time delay matrix in step 2 are as follows: Step 2.1: The sound source emits a sinusoidal pulse signal with a period of T and a duty cycle of h, and records the response waveform of each channel. For the i-th hydrophone, record the positive output signal p. i,+ [n] and negative output signal p i,- [n], where n is the sampling timing of the digital signal; Step 2.2: Using the positive output of channel 1 as the standard, calculate the cross-correlation coefficients of the positive outputs of the remaining (N-1) channels relative to channel 1. Specifically, for any -Tf... s / 2<m<Tf s / 2, T is the period of the sinusoidal pulse signal, f s The sampling rate is used to calculate the cross-correlation coefficient r according to formula (1). 1i [m]=r{p 1,+ [n],p i,+ [n+m]}; Step 2.3: Find the maximum value of the cross-correlation coefficient. The corresponding time delay is denoted as M. 1i M 1i It is the time delay for the signal to arrive at the two channels (the first and the i-th); Step 2.4: Using the positive outputs of the 2nd, 3rd, ..., Nth channels as the standard, repeat steps 1.2 to 1.3 to obtain an N x N cross-correlation matrix R = [R ij ] N×N And the time delay matrix M = [M ij ] N×N ; The specific steps for checking the consistency of positive and negative pole orientation between channels in step 3 are as follows. Step 3.1: Based on the cross-correlation matrix R = [R] obtained in Step 2 ij ] N×N And the time delay matrix M = [M ij ] N×N If R ij If the correlation coefficient is greater than th2, then the orientation is considered to be the same; otherwise, the orientation is considered to be opposite. Here, th2 is the threshold for the correlation coefficient. Step 3.2: Set the detection pass rate threshold η. For the i-th channel, if R i1 ,R i2 ,…R iN Among a total of N cross-correlation coefficients, there are proportions greater than η that satisfy R. in If the value is greater than th2, then the orientation is considered the same; otherwise, the orientation is considered opposite.

2. The automated detection method for phase response consistency of a multi-channel hydrophone according to claim 1, characterized in that: The detection threshold th1 and the correlation coefficient determination threshold th2 are adjustable according to the experimental environment.

3. The automated detection method for phase response consistency of a multi-channel hydrophone according to claim 1, characterized in that: The detection threshold th1 is any value between -1 and -0.

9.

4. The automated detection method for phase response consistency of a multi-channel hydrophone according to claim 1, characterized in that: The correlation coefficient threshold th2 is any value between 0.6 and 0.9.

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