A device and method for precise three-dimensional spatial position control of a hydrophone based on acoustic focusing

Abstract

This invention belongs to the field of hydrophone parameter measurement technology, specifically relating to a device and method for precise control of the three-dimensional spatial position of a hydrophone based on acoustic focusing. It includes a multi-channel signal transmitting device, a multi-channel signal acquiring device, a motion mechanism control device, a computer control system, a hydrophone under test, a sound source, a motion mechanism, and three focusing transducers (I, II, and III) arranged in a triangular configuration on the same plane. This invention places the hydrophone under test in the sound field formed by the focusing transducers. Through feedback from the acoustic signals received by each focusing transducer, the positioning mechanism is controlled to move the hydrophone under test until it is placed in a specific spatial position. This achieves precise control of the three-dimensional position of the hydrophone under test in the measurement area, reduces the influence of the placement position on the phase measurement of the hydrophone under test, and exhibits good repeatability.

Description

Technical Field

[0001] This invention belongs to the field of hydrophone parameter measurement technology, specifically relating to a device and method for precise control of the three-dimensional spatial position of a hydrophone based on acoustic focusing. Background Technology

[0002] As the carrier of underwater sound pressure levels, the most important parameter of a standard hydrophone is its sensitivity. IEC 60565-1:2020 and IEC 60565-2:2019 clearly define the sensitivity of a standard hydrophone as a complex quantity; its modulus is what is commonly referred to as sensitivity, and its phase angle is the phase response of the standard hydrophone. Generally, the amplitude response of a hydrophone is relatively less affected by its positioning accuracy; therefore, conventional distance measurements are sufficient for calibration. However, the phase response of a hydrophone is significantly affected by its positioning accuracy, especially at higher test frequencies. This is because the higher the measurement frequency, the shorter the wavelength of the sound wave, and the positioning deviation becomes non-negligible relative to the wavelength, affecting the accuracy of the phase response. For example, at a frequency of 500kHz, the wavelength of a sound wave in water is approximately 3mm; a positioning deviation of 0.2mm would result in a phase deviation of 24°.

[0003] Currently, determining the spatial position of a hydrophone during phase measurement primarily relies on its clamping structure. This involves a rigid connection between the clamping and positioning mechanisms to ensure the hydrophone's spatial position. However, for high-frequency phase measurements, ensuring accuracy places extremely high demands on the precision of the mounting structure and positioning mechanism, significantly increasing the cost of the testing equipment. In reality, the final spatial position of the hydrophone in the sound field is a complex result, depending not only on the precision and accuracy of the mounting and positioning mechanisms themselves, but also on factors such as the personnel involved in the installation, the installation method, and the coordination of the mechanical structure. This approach suffers from poor repeatability; therefore, existing technologies have significant limitations for high-frequency phase response testing. Summary of the Invention

[0004] The purpose of this invention is to provide a method and device for precise control of the three-dimensional spatial position of a hydrophone based on acoustic focusing, in order to overcome the shortcomings of the existing technology.

[0005] This invention provides the following technical solution:

[0006] A precise three-dimensional spatial position control device for a hydrophone based on acoustic focusing includes a multi-channel signal transmitting device, a multi-channel signal acquiring device, a motion mechanism control device, a computer control system, a hydrophone under test, a sound source, a motion mechanism, and three focusing transducers (I, II, and III) arranged in a triangular configuration on the same plane. The multi-channel signal transmitting device outputs multiple sinusoidal electrical signals to excite the three focusing transducers respectively. The multi-channel signal acquiring device acquires the output signals of the three focusing transducers. The motion mechanism control device controls the movement of the motion mechanism, one end of which is connected to the hydrophone under test. The motion mechanism drives the hydrophone under test to a specific spatial position and feeds back the position information to the motion mechanism control device. The motion mechanism control device sends the position information to the computer control system. The computer control system acquires and analyzes the output signals of the multi-channel signal acquiring device. Based on the obtained real-time position information of the motion mechanism, the computer control system issues commands to the motion mechanism control device to adjust the motion mechanism to reach the designated position.

[0007] Furthermore, the acoustic axis connecting the first and second focusing transducers is perpendicular to the acoustic axis of the sound source, and the acoustic axis of the third focusing transducer coincides with the acoustic axis of the sound source.

[0008] Furthermore, the focusing transducer employs concave spherical self-focusing, phased array focusing, or acoustic lens methods to converge high-frequency sound waves, wherein the sound wave frequency of the high-frequency sound waves is above 1MHz.

[0009] Furthermore, the multi-channel signal transmitting device includes three independent output channels, the multi-channel signal acquisition device includes three independent input channels, and the multi-channel signal transmitting device, the multi-channel signal acquisition device, and the motion mechanism control device are all electrically connected to the computer control system 7.

[0010] Furthermore, a sound field is formed between the focusing transducer one, focusing transducer two, and focusing transducer three, and the hydrophone under test is placed in the sound field.

[0011] Furthermore, the multi-channel signal acquisition device also has a synchronous triggering function, which synchronously acquires and displays the three output signals.

[0012] A control method employing the aforementioned acoustic focusing-based hydrophone three-dimensional spatial position precision control device includes the following steps:

[0013] S1, the multi-channel signal transmitting device has three independent output channels that each output sinusoidal pulse electrical signals, the signals being respectively... Where A0 is the signal amplitude, f is the signal frequency, and φ is the signal frequency. i The initial phase of the signal. , indicating the channel number; the multi-channel signal transmitting equipment excites focusing transducer one and focusing transducer two to transmit acoustic signals into the water, and at the same time the output signals of focusing transducer one and focusing transducer two are respectively input to the corresponding channels of the multi-channel signal acquisition equipment;

[0014] S2. The multi-channel signal acquisition device acquires and displays the received signals of focusing transducer one and focusing transducer two, and then adjusts the initial phase of the excitation signals of focusing transducer one and focusing transducer two so that the received signals of focusing transducer one and focusing transducer two reach their maximum.

[0015] S3. Turn off the excitation signal of the focusing transducer one, and excite the focusing transducer two and the focusing transducer three respectively by the multi-channel signal transmitting equipment. Keep the transmission state of the focusing transducer two unchanged, and adjust the initial phase of the excitation signal of the focusing transducer three so that the receiving signals of the focusing transducer two and the focusing transducer three reach the maximum.

[0016] S4. Keep both focusing transducers one and two in operation, and use the computer control system and motion mechanism control equipment to position the hydrophone under test at a certain position on the line connecting the acoustic axes of focusing transducers one and two. ;

[0017] S5. The computer control system acquires the received signals from focusing transducer one and focusing transducer two, and extracts the reflected signals generated by the hydrophone under test. and Among them, B r1 and B r2 φ represents the amplitude of the reflected signals from channels one and two of the focusing transducer, respectively. r1 and φ r2 The phases of the reflected signals from channels one and two of the focusing transducer are given, respectively. The correlation coefficient is calculated based on the time delay between the received and reflected signals. The adjustment direction of the hydrophone under test is determined, and then the computer control system generates control commands to control the motion mechanism to increase the displacement of the hydrophone under test in the adjustment direction. The correlation coefficient is recalculated at the new location and continuously adjusted to maximize the correlation coefficient.

[0018] S6. Keep focusing transducers two and three in operation. The computer control system acquires the received signals from focusing transducers two and three, and extracts the reflected signals generated by the hydrophone under test. and Among them, B r2 and B r3 These represent the amplitudes of the reflected signals from focusing transducer two and focusing transducer three channels, respectively, φ. r2 and φr3 The phases of the reflected signals from the second and third channels of the focusing transducer are given, respectively. The correlation coefficient is calculated based on the time delay between the received and reflected signals. Then, the computer control system controls the motion mechanism to generate an incremental displacement of the hydrophone under test in the adjustment direction. The correlation coefficient is recalculated at the new location and continuously adjusted to maximize the correlation coefficient.

[0019] S7. Repeat steps S5 and S6 until... and All values ​​reached their maximum values, completing the spatial positioning of the hydrophone under test.

[0020] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0021] This invention eliminates phase measurement errors caused by inaccurate placement of hydrophones, enabling accurate measurement of the phase response of high-frequency hydrophones. It also features good operability and repeatability, reducing the high-precision requirements for installation and positioning during high-frequency phase response measurement of hydrophones. This improves measurement accuracy while saving testing costs. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the X-Y and XZ plane structure of the hydrophone three-dimensional spatial position precision control device based on acoustic focusing according to the present invention;

[0023] Figure 2 This is a diagram showing the arrangement of the focusing transducer in the three-dimensional spatial position precise control device for a hydrophone based on acoustic focusing, as described in this invention.

[0024] Figure 3 This is a schematic diagram of the active element of the focusing transducer of the present invention;

[0025] Figure 4 This is a schematic diagram of the "cross-shaped" focusing formed at the focal plane of the focusing transducer of the present invention;

[0026] Figure 5 This is a flowchart illustrating the positioning control process of the three-dimensional spatial precise control device for a hydrophone based on acoustic focusing, as described in this invention.

[0027] The markings in the image are as follows:

[0028] 1-Focusing transducer one; 2-Focusing transducer two; 3-Focusing transducer three; 4-Multi-channel signal transmitting equipment; 5-Multi-channel signal acquisition equipment; 6-Motion mechanism control equipment; 7-Computer control system; 8-Hydrophone under test; 9-Sound source; 10-Motion mechanism. Detailed Implementation

[0029] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings, so that those skilled in the art can more clearly understand how to practice the present invention. Although the present invention has been described in conjunction with its preferred embodiments, these embodiments are merely illustrative and not intended to limit the scope of the invention.

[0030] The control device of this invention is implemented in a free-field measurement tank, while simultaneously calibrating the complex sensitivity of the hydrophone 8 under test. The sound source 9 emits the acoustic signal required for calibration, and the standard hydrophone, i.e., the hydrophone 8 under test, is placed in the sound field generated by the sound source 9. To achieve accurate measurement of the phase response of the hydrophone 8 under test, it is necessary to accurately place the hydrophone 8 at a point in the measurement area to ensure the accuracy and repeatability of the phase measurement.

[0031] As attached Figure 1 As shown, a precise three-dimensional spatial position control device for a hydrophone based on acoustic focusing includes a multi-channel signal transmitting device 4, a multi-channel signal acquiring device 5, a motion mechanism control device 6, a computer control system 7, a hydrophone under test 8, a sound source 9, a motion mechanism 10, and focusing transducers 1-1, 2-2, and 3-3 arranged in a triangular configuration on the same plane. The multi-channel signal transmitting device 4 outputs multiple sinusoidal electrical signals to excite the three focusing transducers respectively. The multi-channel signal acquiring device 5 acquires the output signals of the three focusing transducers. The motion control device 6 controls the movement of the motion mechanism 10. One end of the motion mechanism 10 is connected to the hydrophone 8 under test, and the motion mechanism 10 drives the hydrophone 8 under test to a specific spatial position and feeds back the position information to the motion control device 6. The motion control device 6 sends the position information to the computer control system 7. The computer control system 7 collects and analyzes the output signal of the multi-channel signal acquisition device 5. Based on the real-time position information of the motion mechanism 10 obtained, the computer control system 7 issues instructions to the motion control device 6 to adjust the motion mechanism 10 to reach the specified position.

[0032] Among them, the multi-channel signal transmitting device 4 can provide at least 3 independent sinusoidal electrical signal outputs to excite the three focusing transducers to work respectively. The frequency, amplitude, initial phase and duty cycle of each electrical signal are independently adjustable and can be output synchronously.

[0033] Specifically, the acoustic axis line connecting the first focusing transducer 1 and the second focusing transducer 2 is perpendicular to the acoustic axis of the sound source 9, making the acoustic focal points of the first focusing transducer 1 and the second focusing transducer 2 coincide. The acoustic axis of the third focusing transducer 3 coincides with the acoustic axis of the sound source 9, making the acoustic focal point of the third focusing transducer 3 coincide with the acoustic focal points of the first focusing transducer 1 and the second focusing transducer 2, as shown in the attached figure. Figure 1-2As shown, in the XY plane, focusing transducer 1 and focusing transducer 2 are installed and fixed on both sides of the hydrophone 8 under test in the X direction of the measuring tank. In the XZ plane, focusing transducer 3 is installed on the side of the hydrophone 8 under test away from the sound source 9 in the Y direction of the measuring tank.

[0034] In addition, there are three focusing transducers with an acoustic axis angle of 90° in the same horizontal plane, namely, the acoustic axis angle between focusing transducer 1 and focusing transducer 3 is 90°, and the acoustic axis angle between focusing transducer 3 and focusing transducer 2 is 90°.

[0035] Specifically, the focusing transducer employs concave spherical self-focusing, phased array focusing, or acoustic lens methods to converge high-frequency sound waves. The sound wave frequency is above 1MHz. The focusing transducers refer to focusing transducer 1, focusing transducer 2, and focusing transducer 3, with concave spherical self-focusing being the preferred method for focusing. The high-frequency sound wave frequency is 5MHz. A schematic diagram of the active components of the focusing transducer is attached. Figure 3 As shown. The focusing transducer forms a "cross" shaped focusing pattern on the focal plane parallel to its opening direction, as indicated. Figure 4 The diameter of the -3dB focal spot at the intersection of the "cross" is 0.2mm, the focal length F is 12cm, the three focusing transducers have the same structural parameters, and the acoustic parameters are well consistent.

[0036] Specifically, the multi-channel signal transmitting device 4 includes three independent output channels, the multi-channel signal acquisition device 5 includes three independent input channels, and the multi-channel signal transmitting device 4, the multi-channel signal acquisition device 5, and the motion mechanism control device 6 are all electrically connected to the computer control system 7.

[0037] Specifically, a sound field is formed between the focusing transducer 1, focusing transducer 2, and focusing transducer 3, and the hydrophone 8 to be tested is placed in the sound field.

[0038] Specifically, the multi-channel signal acquisition device 5 also has a synchronous triggering function, which synchronously acquires and displays the three output signals, and has a large dynamic range, enabling high-fidelity acquisition of the transmitted and received signals of the focusing transducer.

[0039] As attached Figure 5 As shown, a control method for a hydrophone's three-dimensional spatial position precision control device based on acoustic focusing includes the following steps:

[0040] S1, the multi-channel signal transmitting device 4 has three independent output channels that output sinusoidal pulse electrical signals respectively, the signals being... Where A0 is the signal amplitude, f is the signal frequency, and φ is the signal frequency. i The initial phase of the signal. , indicating the channel number; the multi-channel signal transmitting device 4 excites focusing transducer 1 and focusing transducer 2 to transmit acoustic signals into the water, and at the same time the output signals of focusing transducer 1 and focusing transducer 2 are respectively input to the corresponding channels of the multi-channel signal acquisition device 5;

[0041] S2. The multi-channel signal acquisition device 5 acquires and displays the received signals of the focusing transducer 1 and the focusing transducer 2, and then adjusts the initial phase of the excitation signals of the focusing transducer 1 and the focusing transducer 2 to maximize the received signals of the focusing transducer 1 and the focusing transducer 2.

[0042] S3. Turn off the excitation signal of the focusing transducer 1. The multi-channel signal transmitting device 4 excites the focusing transducer 2 and the focusing transducer 3 respectively. Keep the transmission state of the focusing transducer 2 unchanged. Adjust the initial phase of the excitation signal of the focusing transducer 3 so that the receiving signals of the focusing transducer 2 and the focusing transducer 3 reach the maximum.

[0043] S4. Keep focusing transducers 1 and 2 in working condition, and use the computer control system 7 and motion mechanism control device 6 to position the hydrophone 8 under test at a certain position on the line connecting the acoustic axes of focusing transducers 1 and 2. ;

[0044] S5, the computer control system 7 acquires the received signals from focusing transducer 1 and focusing transducer 2, and extracts the reflected signals generated by the hydrophone 8 under test. and Among them, B r1 and B r2 φ represents the amplitude of the reflected signals from channels 1 and 2 of focusing transducer 1 and focusing transducer 2, respectively. r1 and φ r2 The phases of the reflected signals from channels 1 and 2 of focusing transducer 1 and focusing transducer 2, respectively, are used to calculate the correlation coefficient based on the time delay between the received and reflected signals. The adjustment direction of the hydrophone 8 under test is determined, and then the computer control system 7 generates a control command to control the motion mechanism 10 to increase the displacement of the hydrophone 8 under test in the adjustment direction. The correlation coefficient is recalculated at the new location and continuously adjusted to maximize the correlation coefficient.

[0045] S6. Keep focusing transducers 2 and 3 in operation. The computer control system 7 collects the received signals from focusing transducers 2 and 3, and extracts the reflected signals generated by the hydrophone 8 under test. and Among them, B r2 and Br3 φ represents the amplitude of the reflected signals from channels 2 and 3 of focusing transducer two, respectively. r2 and φ r3 The phases of the reflected signals from channels 2 of focusing transducer two and channel 3 of focusing transducer three are given, and their correlation coefficients are calculated based on the time delay between the received and reflected signals. Then, the computer control system 7 controls the motion mechanism 10 to generate an incremental displacement of the hydrophone 8 under test in the adjustment direction. The correlation coefficient is recalculated at the new location and continuously adjusted to maximize the correlation coefficient.

[0046] S7. Repeat steps S5 and S6 until... and All reached their maximum values, completing the spatial positioning of the hydrophone 8 under test.

[0047] Compared with existing high-frequency hydrophone phase response testing, which places extremely high demands on the clamping and motion positioning mechanisms, this invention greatly simplifies the requirements for the motion mechanism 10. By employing three high-frequency focusing transducers arranged at 90°, and utilizing the converging effect and high resolution of high-frequency focused ultrasound waves, the position of the hydrophone 8 under test can be determined in three-dimensional space without imposing higher precision requirements on the motion mechanism 10. By adjusting parameters such as the operating frequency of the focusing transducers, the spatial positioning accuracy resolution of the hydrophone 8 under test can be better than 0.05mm. Compared with existing solutions, this invention has significant advantages. The analysis results of the focusing transducer signals by the computer control system 7 can be fed back in real time to control the motion mechanism 10 to place the hydrophone 8 under test in an accurate position. This solves the problems of low positioning accuracy and poor repeatability of hydrophones during phase response testing, significantly improving measurement accuracy while saving testing costs.

[0048] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications and substitutions based on the technical solutions and inventive concepts provided by the present invention should be covered within the scope of protection of the present invention.

Claims

1. A device for precise three-dimensional spatial position control of a hydrophone based on acoustic focusing, characterized in that: The system includes a multi-channel signal transmitting device (4), a multi-channel signal acquisition device (5), a motion mechanism control device (6), a computer control system (7), a hydrophone under test (8), a sound source (9), a motion mechanism (10), and three focusing transducers (1), 2, and 3) arranged in a triangular configuration on the same plane. The multi-channel signal transmitting device (4) outputs multiple sinusoidal electrical signals to excite the three focusing transducers respectively. The multi-channel signal acquisition device (5) acquires the output signals of the three focusing transducers. The motion mechanism control device (6) controls the motion mechanism (10). The movement mechanism (10) is connected to the hydrophone (8) under test at one end, and the movement mechanism (10) drives the hydrophone (8) under test to be placed in a specific spatial position and feeds back the position information to the movement mechanism control device (6). The movement mechanism control device (6) sends the position information to the computer control system (7). The computer control system (7) collects and analyzes the output signal of the multi-channel signal acquisition device (5). The computer control system (7) sends an instruction to the movement mechanism control device (6) to adjust the movement mechanism (10) to reach the specified position through the real-time position information of the movement mechanism (10).

2. The device for precise three-dimensional spatial position control of a hydrophone based on acoustic focusing according to claim 1, characterized in that: The acoustic axis of the focusing transducer one (1) and the focusing transducer two (2) is perpendicular to the acoustic axis of the sound source (9), and the acoustic axis of the focusing transducer three (3) coincides with the acoustic axis of the sound source (9).

3. The precise three-dimensional spatial position control device for a hydrophone based on acoustic focusing according to claim 1, characterized in that: The focusing transducer uses concave spherical self-focusing, phased array focusing, or acoustic lens methods to converge high-frequency sound waves, and the sound wave frequency of the high-frequency sound waves is above 1MHz.

4. The device for precise three-dimensional spatial position control of a hydrophone based on acoustic focusing according to claim 1, characterized in that: The multi-channel signal transmitting device (4) includes three independent output channels, the multi-channel signal acquisition device (5) includes three independent input channels, and the multi-channel signal transmitting device (4), the multi-channel signal acquisition device (5) and the motion mechanism control device (6) are all electrically connected to the computer control system (7).

5. The precise three-dimensional spatial position control device for a hydrophone based on acoustic focusing according to claim 1, characterized in that: A sound field is formed between the focusing transducer one (1), the focusing transducer two (2) and the focusing transducer three (3), and the hydrophone to be tested (8) is placed in the sound field.

6. The device for precise three-dimensional spatial position control of a hydrophone based on acoustic focusing according to claim 1, characterized in that: The multi-channel signal acquisition device (5) also has a synchronous triggering function to synchronously acquire and display the three output signals.

7. A control method using the acoustic focusing-based hydrophone three-dimensional spatial position precision control device as described in any one of claims 1-6, characterized in that: Includes the following steps: S1, Multi-channel signal transmitting device (4) has three independent output channels that output sinusoidal pulse electrical signals respectively. Where A0 is the signal amplitude, f is the signal frequency, and φ is the signal frequency. i The initial phase of the signal. , indicating the channel number; the multi-channel signal transmitting device (4) excites the focusing transducer one (1) and the focusing transducer two (2) to transmit acoustic signals into the water, and at the same time the output signals of the focusing transducer one (1) and the focusing transducer two (2) are respectively input to the corresponding channels of the multi-channel signal acquisition device (5); S2. The multi-channel signal acquisition device (5) acquires and displays the received signals of the first (1) and the second (2) of the focusing transducer, and then adjusts the initial phase of the excitation signals of the first (1) and the second (2) of the focusing transducer to maximize the received signals of the first (1) and the second (2). S3. Turn off the excitation signal of the first (1) of the focusing transducer, and excite the second (2) and the third (3) of the focusing transducer by the multi-channel signal transmitting device (4) respectively. Keep the transmission state of the second (2) of the focusing transducer unchanged, and adjust the initial phase of the excitation signal of the third (3) of the focusing transducer so that the receiving signals of the second (2) and the third (3) of the focusing transducer reach the maximum. S4. Keep the focusing transducer one (1) and the focusing transducer two (2) in working condition, and use the computer control system (7) and the motion mechanism control device (6) to place the hydrophone under test (8) at a certain position on the line connecting the acoustic axes of the focusing transducer one (1) and the focusing transducer two (2). ; S5. The computer control system (7) collects the received signals from focusing transducer one (1) and focusing transducer two (2), and extracts the reflected signals generated by the hydrophone under test (8). and Among them, B r1 and B r2 The amplitudes φ of the reflected signals from the channels of focusing transducer one (1) and focusing transducer two (2) are respectively. r1 and φ r2 The phases of the reflected signals from channels one (1) and two (2) of the focusing transducer are respectively used. Based on the time delay between the received and reflected signals, their correlation coefficients are calculated. The adjustment direction of the hydrophone (8) under test is determined, and then the computer control system (7) generates a control command to control the motion mechanism (10) to generate an incremental displacement of the hydrophone (8) under test in the adjustment direction. The correlation coefficient is recalculated at the new location and continuously adjusted to maximize the correlation coefficient. S6. Keep focusing transducers 2 (2) and 3 (3) in working condition. The computer control system (7) collects the received signals from focusing transducers 2 (2) and 3 (3) and extracts the reflected signals generated by the hydrophone under test (8). and Among them, B r2 and B r3 The amplitudes φ of the reflected signals from channels 2 and 3 of the focusing transducer are respectively. r2 and φ r3 The phases of the reflected signals from channels 2 and 3 of the focusing transducer are given respectively. Based on the time delay between the received and reflected signals, their correlation coefficients are calculated. Then, the computer control system (7) controls the motion mechanism (10) to generate an incremental displacement of the hydrophone (8) under test in the adjustment direction. The correlation coefficient is recalculated at the new location and continuously adjusted to maximize the correlation coefficient. S7. Repeat steps S5 and S6 until... and All reach their maximum values, completing the spatial positioning of the hydrophone (8) under test.

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