Array transducer sensitivity testing device and method based on multiple pulse sequences

Abstract

The invention discloses a device and a method for testing the sensitivity of an array transducer based on a multi-pulse sequence. The device comprises a signal generator, a transmitting system, a receiving system and a data processing unit, the signal generator is used for generating and outputting a characteristic multi-frequency pulse sequence comprising a plurality of frequency points to be measured, the characteristic multi-frequency pulse sequence comprises a frequency point sequence of which the frequencies are arranged from small to large, the front end of the characteristic multi-frequency pulse sequence is provided with a characteristic signal of which the time width is T, and the time length of a single-group discrete pulse sequence is (n + 1) * T (n is the total number of the frequency points to be measured); and the transmitting system comprises a signal source, a power amplifier and a transmitting sound source which are connected in sequence, and is used for converting the characteristic multi-frequency pulse sequence into an underwater acoustic signal for transmitting. The invention solves the problems of poor adaptability, low data accuracy and low efficiency of a single array element sensitivity test system after array transducer array forming in the prior art, provides the array transducer sensitivity test system based on the multi-pulse sequence, and realizes efficient and accurate measurement of the sensitivity of a single transducer in an array.

Description

Technical Field

[0001] This invention relates to an array transducer sensitivity testing device and method based on multi-pulse sequences. Background Technology

[0002] In the field of underwater acoustic transducer array measurement, transducer sensitivity is a key indicator for evaluating its performance. Existing sensitivity measurement schemes have significant drawbacks: firstly, they primarily target the measurement of individual transducers in a water tank, failing to consider the limitations of system setup for single-element testing after array formation, thus failing to meet the actual testing requirements of arrayed transducers; secondly, the measurement process relies on manual oscilloscope readings, which are prone to human error leading to inaccurate data, and in multi-pulse scenarios, frequent operations consume significant time, resulting in low efficiency. Therefore, there is an urgent need for a sensitivity testing system that can adapt to the testing requirements of arrayed transducers and improve accuracy and efficiency. Summary of the Invention

[0003] The present invention aims to solve the problems of poor adaptability, low data accuracy and low efficiency of the existing single array element sensitivity testing system after arraying of array transducers, and provides an array transducer sensitivity testing system based on multi-pulse sequence to achieve efficient and accurate measurement of the sensitivity of individual transducers in the array.

[0004] To solve the above problems, the technical solution of the present invention is as follows: A sensitivity testing device for array transducers based on multi-pulse sequences includes a signal generator, a transmitting system, a receiving system, and a data processing unit. The signal generator generates and outputs a characteristic multi-frequency pulse sequence containing multiple test frequencies. The characteristic multi-frequency pulse sequence contains a sequence of frequencies arranged from smallest to largest and is preceded by a characteristic signal with a time width of T. The time length of a single discrete pulse sequence is (n+1)×T (where n is the total number of test frequencies). The transmitting system includes a signal source, a power amplifier, and a sound source connected in sequence, used to convert the characteristic multi-frequency pulse sequence into an underwater acoustic signal for transmission. The receiving system includes an array data receiving module and a hydrophone data receiving module. The array data receiving module includes an array, an electronic chamber, and a computer. The hydrophone data receiving module includes a hydrophone, a standard filter amplifier, an AD acquisition module, and a computer. The computer is used to simultaneously receive and store the signals from the transducer under test and the standard hydrophone. The data processing unit is used to obtain the amplitude value of each frequency point through the pulse detection algorithm, and to calculate the sensitivity of each frequency point of the transducer under test based on the free field standard hydrophone comparison method.

[0005] Furthermore, the frequency point sequence of the characteristic multi-frequency pulse sequence is as follows: ; In the formula: This represents the frequency value of the point to be measured. n This indicates the total number of frequency points to be measured; Number of cycles at each frequency point for: ; In the formula: T f For pulse width at all frequencies, This indicates rounding down to the nearest integer.

[0006] Furthermore, the time width of each frequency point in the characteristic multi-frequency pulse sequence within the discrete signal sequence is expanded by padding with leading zeros to... T The period of each frequency point is T The effective pulse length is T f .

[0007] Furthermore, the waveform selected by the signal generator is an "Arb" arbitrary wave, the data source of the wave is an imported "*.raf" format characteristic multi-frequency pulse sequence data file, and the sampling rate of the arbitrary wave is set to... Amplitude set The offset and phase are all set to 0.

[0008] Furthermore, the data duration for the dual-network port computer to receive and store signals is no less than 2T, where T is the time width of each frequency point in the discrete signal sequence.

[0009] A sensitivity testing method for array transducers based on multi-pulse sequences includes the following steps: Step 1: Generate and output a characteristic multi-frequency pulse sequence containing multiple test frequencies. The characteristic multi-frequency pulse sequence contains a frequency sequence arranged from small to large frequencies and has a characteristic signal at the front end. Step 2: The characteristic multi-frequency pulse sequence is converted into underwater acoustic signals and transmitted through the transmitting system. At the same time, the underwater acoustic signals received by the transducer under test and the standard hydrophone in the array are collected by the receiving system and converted into electrical signals for storage. Step 3: Preprocess the stored electrical signals by identifying the pulse positions and calculating the amplitude values ​​of the pulse signals at each frequency point using a pulse detection algorithm. Step four: Based on the amplitude values ​​of the standard hydrophone and the transducer under test, combined with the standard hydrophone sensitivity calibration data and system gain, the sensitivity of each frequency point of the transducer under test in the array is calculated using the free-field standard hydrophone comparison method.

[0010] Furthermore, the step one of generating the characteristic multi-frequency pulse sequence includes: determining the frequency point sequence. Set the sampling frequency f s Pulse widthT f Calculate the number of cycles at each frequency point. Extend the time width of each frequency point to T Add a time width to the front end T The characteristic signal is used to generate a single set of time lengths. The discrete pulse sequence is generated; the discrete pulse sequence is saved as "*.raf" format and imported into the signal generator output.

[0011] Furthermore, step three, pulse position identification, includes: convolving an array of a predetermined length with the filtered discrete pulse sequence to obtain energy data, wherein the array length is... , Represents a coefficient, with a range of The `findPeaks` function is used to locate energy peak points and obtain a sequence of their positions. In the formula: Indicates the sequence of locations of energy spikes; Indicates the minimum height for energy peak lookup. This represents the shortest distance between two energy peaks. Used to prevent the detection of peaks generated by interference signals; based on the time width of adjacent peak points. , ; In the formula: , representing a coefficient used to identify the time width of the starting feature position.

[0012] Furthermore, step three involves calculating the amplitude values ​​at each frequency point, based on the pulse start position sequence: and pulse width Tf, The peak points of a single-frequency signal can be identified using the findPeaks function. The formula for peak identification is as follows: ; Discard the unsteady peaks at the beginning and end, and take the middle one. One steady-state peak ( Calculate peak-to-peak value (for multiples of 2). , ; according to Calculate the amplitude value.

[0013] Furthermore, in step four, sensitivity is calculated. , The formula is: ; In the formula: This represents the sensitivity sequence corresponding to the frequency point of the transmitted signal. This represents the amplitude value of the transducer under test in the array. This represents the overall acquisition system gain of the array. This indicates the amplitude value of a standard hydrophone. This indicates the acquisition system gain of a standard hydrophone. This represents the sensitivity sequence of a standard hydrophone at a corresponding frequency.

[0014] The beneficial effects of this invention are as follows: This invention outputs all the signals of the frequency points to be tested at one time through a characteristic multi-frequency pulse sequence, which greatly improves the testing efficiency; the dual network port computer synchronously acquires signals to ensure the consistency of measurement conditions and reduce errors; the automated algorithm replaces manual readings and improves data accuracy; the system is adapted to the testing environment after the array transducer is assembled, effectively solves the limitations of the existing technology, and provides strong support for the performance verification of array transducers. Attached Figure Description

[0015] The invention will be further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a single-frequency pulse signal according to the present invention; Figure 2 This is a schematic diagram of the complete pulse sequence of the present invention; Figure 3 This is a schematic diagram of the array underwater acoustic transducer sensitivity measurement system of the present invention; Figure 4 The figure shows a schematic diagram of the discrete pulse sequence before and after filtering acquired by the present invention. In the figure, (a) is a schematic diagram of the entire set of acquired data, and (b) is a schematic diagram of the acquired data at a single frequency point. Figure 5 This is a schematic diagram of the received data and its energy data normalization according to the present invention. In the figure, (a) is a schematic diagram of the entire set of data; and (b) is a schematic diagram of the data at a single frequency point. Figure 6 This is a schematic diagram of energy peak identification according to the present invention. In the figure, (a) is the energy peak of the entire data segment; and (b) is a magnified schematic diagram of the energy peak at position ①. Figure 7 This is a schematic diagram illustrating the pulse sequence start position feature recognition of the present invention; Figure 8 This is a schematic diagram of single-frequency pulse signal peak recognition according to the present invention. In the figure, (a) is the recognition of the peak value of the entire group of single-frequency pulses; and (b) is the recognition of the peak value of a single frequency point of the pulse signal. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] A sensitivity testing device for array transducers based on multi-pulse sequences, such as Figure 3 As shown, it includes a signal generator, a transmitting system, a receiving system, and a data processing unit. The signal generator is used to generate and output a characteristic multi-frequency pulse sequence containing multiple test frequencies. The characteristic multi-frequency pulse sequence contains a frequency sequence arranged from smallest to largest frequency and has a characteristic signal with a time width of T at the beginning. The time length of a single discrete pulse sequence is T. S = (n+1)×T (where n is the total number of frequency points to be tested); the transmitting system includes a signal source, a power amplifier, and a sound source connected in sequence, used to convert the characteristic multi-frequency pulse sequence into underwater acoustic signals for transmission; the receiving system includes an array data receiving module and a hydrophone data receiving module. The array data receiving module includes an array, an electronic chamber, and a computer. The hydrophone data receiving module includes a hydrophone, a standard filter amplifier, an AD acquisition module, and a computer. The computer is used to simultaneously receive and store the signals from the transducer under test and the standard hydrophone; the data processing unit is used to obtain the amplitude value of each frequency point through a pulse detection algorithm and calculate the sensitivity of each frequency point of the transducer under test based on the free-field standard hydrophone comparison method.

[0018] In implementation: such as Figure 1 As shown, the signal generator generates a characteristic multi-frequency pulse sequence based on the frequency to be measured, and determines the frequency sequence arranged from smallest to largest frequency. The front-end is set to a time width of T Characteristic signals, such as Figure 2 As shown, the length of a single group is The transmitting system receives the sequence output from the signal generator, amplifies it with a power amplifier, and then transmits it as an underwater acoustic signal. The receiving system's array data receiving module transmits the signal to be measured to the computer via the array and electronic housing. The standard hydrophone data receiving module transmits the standard signal to the dual-network-port computer via the standard hydrophone, filter amplifier, and AD acquisition module for synchronous storage, with a reception duration of no less than 2T. The data processing unit processes the stored signal, obtains the amplitude value through a pulse detection algorithm, and then bases it on a sensitivity sequence. The formula for calculating the sensitivity at each frequency point is as follows: ; In the formula: This represents the sensitivity sequence corresponding to the frequency points of the transmitted signal; This represents the sensitivity sequence of a standard hydrophone at corresponding frequency points. This represents the amplitude value of the transducer under test in the array; This indicates the amplitude value of a standard hydrophone; This represents the overall acquisition system gain of the array; This indicates the acquisition system gain of a standard hydrophone.

[0019] This enables full automation of the process from signal generation to sensitivity calculation, adapting to the testing needs after array transducers are assembled. Sensitivity at all frequencies can be obtained in a single test, improving efficiency and accuracy and overcoming the limitations of existing technologies.

[0020] Furthermore, by setting the frequency sequence and pulse width, the number of cycles at each frequency point is calculated to ensure the regularity and consistency of the signals at each frequency point in the pulse sequence. The process is as follows: determine the frequency sequence to be measured. Set the pulse width for all frequencies to . T f The number of pulse cycles at a single frequency point satisfies According to the formula: ; Calculate the number of cycles at each frequency point. T f For pulse width at all frequencies, This is for rounding down to the nearest integer. The frequency value of the point to be measured. For each frequency point, a sequence of period numbers is provided to ensure that each frequency point is within the pulse width. T f The number of cycles within a period is an integer.

[0021] This ensures that pulses at each frequency point have a reasonable number of cycles with the same width, guaranteeing the standardization of the pulse signal, providing a unified benchmark for subsequent signal detection and amplitude calculation, and reducing errors caused by inconsistent frequency parameters.

[0022] Furthermore, when generating discrete pulse sequences, based on multi-frequency pulse sequences... Formula and number of cycles The formula determines the frequency sequence and number of periods. The time width of the signal at each frequency point in the discrete sequence is extended to T by padding with leading zeros, ensuring that the period of each frequency point is T, while the effective pulse length remains constant. T f This ensures that pulse signals at different frequencies are separated from each other in time. It effectively avoids overlapping interference between pulses at different frequencies, making each pulse signal independently distinguishable, facilitating subsequent pulse position identification and signal extraction, and improving the accuracy of signal processing.

[0023] Furthermore, frequency-based pulse sequences Number of pulse cycles N, number of cycles and time length T s The generated discrete pulse sequence is saved as a "*.raf" format data file and imported into the signal generator via a storage medium. The signal generator waveform is selected as "Arb" arbitrary wave, the imported file is selected as the data source, and the arbitrary wave sampling rate is set to... , amplitude The offset and phase are set to 0, and then a pulse sequence is output. This ensures that the signal generator can accurately reproduce the characteristic multi-frequency pulse sequence of the design, guaranteeing the accuracy and stability of the transmitted signal and providing a reliable signal source for the entire test system.

[0024] Furthermore, when receiving signals, the dual-port computer uses the period T of the discrete pulse signal sequence and the time length T of a single sequence according to Equation 4. s Set the reception duration to no less than 2T to ensure that at least two complete pulse sequence data can be acquired. This avoids incomplete data due to insufficient reception duration, provides a sufficient data foundation for screening valid pulse sequences and eliminating interference signals during data processing, and improves the reliability of measurement results.

[0025] A sensitivity testing method for array transducers based on multi-pulse sequences includes the following steps: Step 1: Generate and output a characteristic multi-frequency pulse sequence containing multiple test frequencies. The characteristic multi-frequency pulse sequence contains a frequency sequence arranged from small to large frequencies and has a characteristic signal at the front end. Step 2: The characteristic multi-frequency pulse sequence is converted into underwater acoustic signals and transmitted through the transmitting system. At the same time, the underwater acoustic signals received by the transducer under test and the standard hydrophone in the array are collected by the receiving system and converted into electrical signals for storage. Step 3: Preprocess the stored electrical signals by identifying the pulse positions and calculating the amplitude values ​​of the pulse signals at each frequency point using a pulse detection algorithm. Step four: Based on the amplitude values ​​of the standard hydrophone and the transducer under test, combined with the standard hydrophone sensitivity calibration data and system gain, the sensitivity of each frequency point of the transducer under test in the array is calculated using the free-field standard hydrophone comparison method.

[0026] Furthermore, the generation of the characteristic multi-frequency pulse sequence in step one includes: 1. Based on the frequency points required for measuring the sensitivity of the transducer under test, determine the frequency point sequence arranged from smallest to largest. for: Formula 1; in: This represents the frequency value of the point to be measured. n This indicates the total number of frequency points to be measured; 2. Based on the signal sequence from the previous step, generate a discretized pulse sequence. At this point, set the sampling frequency for discretization. f s The pulse width at all frequencies is T f The number of pulse cycles at a single frequency point is N Then the following condition is met: Formula 2 ； To ensure that the pulse widths formed at all frequencies remain consistent, the number of periods at each frequency of the discretized pulse sequence can be obtained according to Equations 1 and 2. for: Formula 3; in: Indicates rounding down to the nearest integer; n Indicates the total number of frequency points to be measured Meanwhile, in order to separate the individual pulses and facilitate subsequent pulse detection, the time width of each frequency point in the discrete signal sequence is extended by padding the pulse signal with zeros. T ,like Figure 1 As shown, the period of each frequency point is T The effective pulse length is T f .

[0027] 3. During signal transmission, a series of pulse sequences are often transmitted cyclically. Therefore, to increase the identifiable characteristics of the starting point of the signal sequence during repeated transmission, a time-width interval is added to the very beginning of the discretized sequence. T The characteristic signal, whose amplitude can be set to 0, then a single discrete pulse sequence is as follows: Figure 2 As shown: The time length of a single discrete pulse sequence is: Equation 4; 4. Save the discrete pulse sequence as a "*.raf" format data file that the signal generator can read, and then import the data file into the signal generator via a storage medium. Select "Arb" arbitrary wave as the waveform in the signal generator, and select the imported data file as the data source for the wave; then set the arbitrary wave sampling rate to... Amplitude set Set the offset and phase to 0; finally, set the signal generator output to generate a discrete pulse sequence for transmission.

[0028] The generated characteristic multi-frequency pulse sequence is standardized and complete, containing all the information to be tested, and can be accurately output by the signal generator, providing a high-quality signal source for subsequent tests and improving the effectiveness of the tests.

[0029] Furthermore, the data preprocessing method in step three includes: performing AD decoding on the data file uploaded by the acquisition device, and performing FIR numerical filtering based on the frequency range of the pulse sequence to obtain the signals of the acquired discrete pulse sequence before and after filtering, such as... Figure 4 As shown.

[0030] Furthermore, step three, pulse position identification, includes: Pulse position identification is achieved by setting an array of a limited length, with all data in the array initially set to 1. Then, the set array and the filtered discrete pulse sequence data are discretely convolved to obtain the energy data of the acquired data with the set array size as the window. Finally, the findPeaks function is used to find the energy peak points to confirm the position of the pulse corresponding to each frequency point in the data file.

[0031] First, determine the length of the array. Based on the width of the frequency signal of the pulse sequence, set the array length accordingly. Set as: Equation 5; in: Represents a coefficient, with a range of , used to precisely control the array length.

[0032] Then, a convolution operation is performed between the array and the filtered discrete pulse sequence data, as shown in Equation 6, to obtain the energy sequence of the received discrete pulse sequence data. : Equation 6; in: This represents a discrete sequence of received data. This represents a discrete sequence of points in a given array. This is the index value of the energy sequence. (in , Do not set the length of the array for the discrete point sequence); The hysteresis index value and range of convolution operations arrive ; The preprocessed data is then subjected to an energy sequence. The energy sequence obtained by the convolution operation of the formula is shown in Figure 5: according to Figure 5 As can be seen, the location of the pulse signal can be confirmed by finding the peak points in the energy sequence. The sequence of positions corresponding to the peaks is implemented by the findPeaks function, which is used to automatically identify local maximum points in the energy data that exceed a set threshold. Its calling format satisfies Equation 7: Equation 7; in: Indicates the sequence of locations of energy spikes; Indicates the minimum height for energy peak lookup. This represents the shortest distance between two energy peaks. Used to prevent the detection of peak values ​​generated by interference signals; Equation 7 yields the following diagram illustrating energy peak identification: Figure 6 As shown: Next is the identification of the starting frequency point of the pulse sequence. Based on the characteristics of the transmitted signal, if the time width of two adjacent energy peak points is... If equation 8 is satisfied, then the starting position of a pulse sequence is considered to have been found. This is the first energy peak point of the signal sequence.

[0033] Equation 8; in: , represents a coefficient used to identify the time width of the starting feature position. The value range is based on the pulse period. With sampling rate The product is determined to ensure the uniqueness of the initial feature signal.

[0034] like Figure 7 The diagram shown illustrates the identification of the starting position features of a pulse sequence. The pulse sequence confirmation indicates the existence of the following three situations: Scenario 1: If there are two or more data entries in a set of received data... If the above formula is satisfied, then a complete pulse sequence is considered to exist, and the next step of peak value calculation can be performed directly.

[0035] Scenario 2: If there is only one If the above formula is satisfied, it is necessary to first determine the number of energy peaks starting from that position: if the total number is equal to the total number of frequency points to be measured, then proceed to the next peak calculation; if the total number is less than the total number of frequency points to be measured, then the energy peaks before and after the feature point position need to be combined into a pulse sequence. If the total number of combined energy peaks is equal to the total number of frequency points to be measured, then proceed to the next peak calculation; otherwise, the current data file is invalid.

[0036] Scenario 3: If one If none of the conditions in equation 8 are met, then the current data file is invalid.

[0037] Based on the above steps, the starting position sequence corresponding to each frequency point in the pulse sequence is obtained as follows: Equation 9; in: This indicates the total number of frequency points in the transmitted signal sequence.

[0038] Therefore, by enhancing the signal energy characteristics through convolution operations, and combining peak finding and starting position judgment conditions, the position of the pulse sequence can be accurately identified, providing accurate position information for subsequent amplitude calculation and improving the accuracy of signal processing.

[0039] Furthermore, the method for calculating the amplitude value of a frequency-point pulse signal includes: knowing the starting position sequence of a single-frequency-point pulse. and signal pulse width In this case, the peak point of the single-frequency signal in the region is identified using the following formula: Formula 10; in: This indicates the identified signal peaks and their corresponding positions in the data sequence; This indicates the minimum height when searching for data peaks. This represents the closest distance between two numerical peaks; This represents the total number of frequency points in the transmitted signal sequence; This is the frequency index value. .

[0040] According to Equation 10, the peak-to-peak value of the single-frequency pulse signal corresponding to each identified frequency point is as follows: Figure 8 As shown. To avoid the influence of the unsteady process of ultrasonic transducer start-up and shutdown on signal amplitude, it is necessary to discard... The received signal amplitude is calculated using only the intermediate steady-state peak value among the peaks at the beginning and end of the sequence.

[0041] Among them, the first i The position of the initial peak of a single-frequency pulse in the data sequence satisfy: Formula 11; in: This represents a coefficient indicating the proportion of front-end peaks that are discarded. No. The number of peak points of a single-frequency pulse signal.

[0042] according to Calculation formula and Figure 8 , Figure 8 In (b): Box “①” represents the identified peak data; Box “②” represents the peak data used in the calculation, according to Equation 11 and Figure 8 The first can be obtained i Peak-to-peak value of a single-frequency pulse signal The calculation formula is as follows: Equation 12; in: This indicates the number of frequency points involved in the calculation, and its value is a multiple of 2. Taking even numbers can balance the measurement errors of the positive and negative half-cycle peaks and improve the accuracy of amplitude calculation. This is the index value of the peak point, within a range. arrive .

[0043] According to Equation 12, we can obtain the... i Amplitude value of a single-frequency pulse signal The calculation formula is as follows: Equation 13; By eliminating the influence of non-steady-state processes on signal amplitude, the amplitude value calculated based on the steady-state peak value is more accurate, providing reliable basic data for sensitivity calculation and improving the accuracy of sensitivity measurement.

[0044] Furthermore, in step four, sensitivity is calculated. ,include: 1. Calculate the amplitude values ​​of the standard hydrophone and the transducer under test according to step two. 2. Based on the frequency information of the transmitted signal, query the calibration data of the standard hydrophone's sensitivity level M, and obtain the sensitivity sequence of the standard hydrophone at each frequency point. .

[0045] 3. Based on sensitivity The calculation formula for the sensitivity of the transducer under test based on the comparison method, shown in the formula, calculates the sensitivity sequence corresponding to each frequency point of a single array element. .

[0046] Equation 14; In the formula: This represents the sensitivity sequence corresponding to the frequency point of the transmitted signal. This represents the amplitude value of the transducer under test in the array. This represents the overall acquisition system gain of the array. This indicates the amplitude value of a standard hydrophone. This indicates the acquisition system gain of a standard hydrophone. This represents the sensitivity sequence of a standard hydrophone at a corresponding frequency.

[0047] Using the calibration data of a standard hydrophone as a benchmark, the sensitivity of the transducer under test is accurately calculated by eliminating the influence of factors such as system gain through a comparison method, thus ensuring the reliability and accuracy of the measurement results.

[0048] The embodiments described in this specification are merely examples of implementations of the inventive concept. The scope of protection of this invention should not be considered as limited to the specific forms stated in the embodiments. The scope of protection of this invention also extends to equivalent technical means that can be conceived by those skilled in the art based on the inventive concept.

Claims

1. A sensitivity testing device for array transducers based on multi-pulse sequences, characterized in that, It includes a signal generator, a transmitting system, a receiving system, and a data processing unit; the signal generator is used to generate and output a characteristic multi-frequency pulse sequence containing multiple test frequencies. The characteristic multi-frequency pulse sequence contains a frequency point sequence arranged from smallest to largest frequency and is preceded by a characteristic signal with a time width of T. The time length of a single discrete pulse sequence is T. S = (n+1)×T (where n is the total number of frequency points to be tested); the transmitting system includes a signal source, a power amplifier, and a sound source connected in sequence, used to convert the characteristic multi-frequency pulse sequence into underwater acoustic signals for transmission; the receiving system includes an array data receiving module and a hydrophone data receiving module. The array data receiving module includes an array, an electronic chamber, and a computer. The hydrophone data receiving module includes a hydrophone, a standard filter amplifier, an AD acquisition module, and a computer. The computer is used to simultaneously receive and store the signals from the transducer under test and the standard hydrophone; the data processing unit is used to obtain the amplitude value of each frequency point through a pulse detection algorithm and calculate the sensitivity of each frequency point of the transducer under test based on the free-field standard hydrophone comparison method.

2. The array transducer sensitivity testing device based on multi-pulse sequences according to claim 1, characterized in that, The frequency point sequence of the characteristic multi-frequency pulse sequence is as follows: ； In the formula: This represents the frequency value of the point to be measured. n This indicates the total number of frequency points to be measured; Number of cycles at each frequency point Defined as: ； In the formula: T f For pulse width at all frequencies, This indicates rounding down to the nearest integer.

3. The array transducer sensitivity testing device based on multi-pulse sequences according to claim 1, characterized in that, The time width of each frequency point in the characteristic multi-frequency pulse sequence in the discrete signal sequence is expanded by leading zeros to... T The period of each frequency point is T The effective pulse length is T f .

4. The array transducer sensitivity testing device based on multi-pulse sequences according to claim 1, characterized in that, The waveform selected by the signal generator is an "Arb" arbitrary wave, and the data source for the wave is an imported "*.raf" format characteristic multi-frequency pulse sequence data file. The sampling rate of the arbitrary wave is set to... Amplitude set The offset and phase are all set to 0.

5. The array transducer sensitivity testing device based on multi-pulse sequences according to claim 1, characterized in that, The data duration for the dual-network port computer to receive and store signals is no less than 2T, where T is the time width of each frequency point in the discrete signal sequence.

6. A method for testing the sensitivity of an array transducer based on a multi-pulse sequence as described in any one of claims 1 to 5, characterized in that, Includes the following steps: Step 1: Generate and output a characteristic multi-frequency pulse sequence containing multiple test frequencies. The characteristic multi-frequency pulse sequence contains a frequency sequence arranged from small to large frequencies and has a characteristic signal at the front end. Step 2: The characteristic multi-frequency pulse sequence is converted into underwater acoustic signals and transmitted through the transmitting system. At the same time, the underwater acoustic signals received by the transducer under test and the standard hydrophone in the array are collected by the receiving system and converted into electrical signals for storage. Step 3: Preprocess the stored electrical signals by identifying the pulse positions and calculating the amplitude values ​​of the pulse signals at each frequency point using a pulse detection algorithm. Step four: Based on the amplitude values ​​of the standard hydrophone and the transducer under test, combined with the standard hydrophone sensitivity calibration data and system gain, the sensitivity of each frequency point of the transducer under test in the array is calculated using the free-field standard hydrophone comparison method.

7. The method for testing the sensitivity of an array transducer based on a multi-pulse sequence according to claim 6, characterized in that, Step one, generating the characteristic multi-frequency pulse sequence, includes: determining the frequency point sequence. Set the sampling frequency f s Pulse width T f Calculate the number of cycles at each frequency point. Extend the time width of each frequency point to T Add a time width to the front end T The characteristic signal is used to generate a single set of time lengths. The discrete pulse sequence is generated; the discrete pulse sequence is saved as "*.raf" format and imported into the signal generator output.

8. The method for testing the sensitivity of an array transducer based on a multi-pulse sequence according to claim 6, characterized in that, Step three, pulse position identification, includes: convolving an array of a predetermined length with a filtered discrete pulse sequence to obtain energy data, wherein the array length is... , Represents a coefficient, with a range of The `findPeaks` function is used to locate energy peak points and obtain a sequence of their positions. ； In the formula: Indicates the sequence of locations of energy spikes; Indicates the minimum height for energy peak lookup. This represents the shortest distance between two energy peaks. Used to prevent the detection of peak values ​​generated by interference signals; Based on the time width of adjacent peak points , ； In the formula: , representing a coefficient used to identify the time width of the starting feature position.

9. The method for testing the sensitivity of an array transducer based on a multi-pulse sequence according to claim 6, characterized in that, Step three involves calculating the amplitude values ​​at each frequency point, including: based on the pulse start position sequence. and pulse width T f The peak point of a single-frequency signal can be identified using the findPeaks function. The peak identification formula is as follows: ； Discard the unsteady peaks at the beginning and end, and take the middle one. One steady-state peak ( Calculate the number of (multiples of 2) Peak-to-peak value at each frequency point , ； according to Calculate the amplitude value.

10. The method for testing the sensitivity of an array transducer based on a multi-pulse sequence according to claim 6, characterized in that, Calculate sensitivity in step four , The formula is: ； In the formula: This represents the sensitivity sequence corresponding to the frequency points of the transmitted signal; This represents the amplitude value of the transducer under test in the array; This represents the overall acquisition system gain of the array; This indicates the amplitude value of a standard hydrophone; Indicates the acquisition system gain of a standard hydrophone; This represents the sensitivity sequence of a standard hydrophone at a corresponding frequency.

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