An automated method for measuring sound fields

Abstract

The present invention belongs to the technical field of sound field measurement, and particularly relates to an automated method for measuring a sound field, comprising the following steps: 1) Establish a transducer coordinate system, where the acoustic axis of the transducer is coaxial with the X-axis, Y-axis, or Z-axis. The automated control module preliminarily determines the coordinates of the focal point F based on the focal length of the transducer and controls the hydrophone to automatically move to point F; 2) The automated control module controls the three-dimensional motion module to drive the hydrophone to perform multiple scans along the X-axis, Y-axis, and Z-axis respectively with point F as the reference to determine the focal point coordinates (X n , Y n , Z n ); 3) The automated control module controls the three-dimensional motion module to drive the hydrophone to first perform a one-dimensional sound pressure distribution scan, then a surface scan, and then a three-dimensional volume scan; 4) End the scan. The present invention realizes the automatic determination of the transducer focal point coordinates and the automated measurement of the sound field, reduces the degree of manual participation, lowers the experience requirements for operators, and improves the safety and measurement efficiency of the equipment.

Description

Technical Field

[0001] The present invention belongs to the technical field of sound field measurement, and particularly relates to an automated method for measuring sound fields. Background Art

[0002] The sound field characteristics of focused ultrasound are mainly measured by a hydrophone to measure its sound pressure distribution and sound field. Currently, the measurement of the focused ultrasound sound field mainly relies on manual operation. First, manually find the geometric focus position of the transducer, then perform sound field scanning and corresponding calculations to obtain the sound field. First, perform non-axis scanning. Set a rough scanning range, scanning speed, and scanning interval. Determine the maximum value point according to the one-dimensional scanning result, move the hydrophone to this point, and then repeat the operation on another non-axis; secondly, perform axis scanning. Set a rough scanning range, scanning speed, and scanning interval, determine the maximum value point according to the one-dimensional scanning result, and move the hydrophone to this point; then repeat the operations of the above three axes in sequence until the difference in the maximum value points in the scanning results is very small, which is regarded as finding the approximate position of the geometric focus of the transducer. Perform fine scanning to further determine the geometric focus of the transducer. First, perform non-axis fine scanning, reduce the scanning range and scanning speed, and repeat the above operations to find the maximum value point; then perform axis scanning, reduce the scanning range and scanning speed, and repeatedly repeat the above operations until the difference in the maximum value points in the scanning results is very small, which is regarded as finding the geometric focus position of the transducer. After finding the geometric focus position of the transducer, perform one-dimensional sound pressure distribution scanning, two-dimensional surface scanning, and three-dimensional volume sound field scanning, and then complete the measurement of the focused ultrasound sound field.

[0003] The above sound field measurement method mainly relies on manual operation and experience. For example, initially, visually predict the geometric focus position of the transducer and rely on manual operation of the three-dimensional motion system to drive the hydrophone to determine the geometric focus position of the transducer. Especially for the determination of the geometric focus position of the transducer, it requires manual exploration and continuous attempts to obtain experience. Especially when using a hydrophone with lower sensitivity, such as a fiber optic hydrophone, it is more difficult to determine the geometric focus position of the transducer. For beginners, it is very difficult to master the above sound field measurement method, and beginners are prone to accidents such as the hydrophone hitting the transducer during operation. Moreover, the above sound field measurement method requires a large amount of rough scanning and fine scanning work, resulting in long time consumption and low efficiency. Summary of the Invention

[0004] The present invention aims to provide an automated method for measuring sound fields to solve the problems of the traditional sound field measurement method, which requires experience, takes a long time, and has low efficiency.

[0005] To achieve the above object, the solution of the present invention is: an automated method for measuring sound fields, including the following steps:

[0006] S1. Preliminary determination of the geometric focus coordinates of the transducer: Establish a transducer coordinate system where the acoustic axis of the transducer is coaxial with the X-axis, Y-axis, or Z-axis. Based on the focal length R of the transducer, the automation control module preliminarily determines that the geometric focus of the transducer is point F, and the coordinates of point F are (X0, Y0, Z0). The three-dimensional motion module drives the hydrophone to move to point F under the control of the automation control module;

[0007] S2. X-axis scanning: Determine that the scanning interval length is N. The three-dimensional motion module drives the hydrophone to move and scan along the X-axis. The scanning interval is [X0 - N / 2: X0 + N / 2, Y0, Z0]. The hydrophone collects the voltage signals within this scanning interval and records the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X1, Y0, Z0);

[0008] S3. Y-axis scanning: The three-dimensional motion module drives the hydrophone to move and scan along the Y-axis. The scanning interval is [X1, Y0 - N / 2: Y0 + N / 2, Z0]. The hydrophone collects the voltage signals within this scanning interval and records the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X1, Y1, Z0);

[0009] S4. Z-axis scanning: The three-dimensional motion module drives the hydrophone to move and scan along the Z-axis. The scanning interval is [X1, Y1, Z0 - N / 2: Z0 + N / 2]. The hydrophone collects the voltage signals within this scanning interval and records the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X1, Y1, Z1);

[0010] S5. Repeat steps S2 - S4. During the repetition process, the scanning interval of the X-axis is [X n-1 - N / 2 + 10(n - 1): X n-1 + N / 2 - 10(n - 1), Y n-1 , Z n-1 , and record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X n , Y n-1 , Z n-1 ). The scanning interval of the Y-axis is [X n , Y n-1 - N / 2 + 10(n - 1): Y n-1 + N / 2 - 10(n - 1), Z n-1 , and record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X n , Y n , Z n-1 ). The scanning interval of the Z-axis is [X n , Y n , Z n-1-N / 2 + 10(n - 1):Z n-1 + N / 2 - 10(n - 1)], record the position coordinates of the maximum value of the voltage signal or the position coordinates of the midpoint of the peak-to-peak distance between two symmetric waves (X n , Y n , Z n ), where n successively takes positive integers greater than 1 until the error of the position coordinates of the maximum value of the voltage signal collected by the hydrophone on the X-axis, Y-axis, and Z-axis or the error of the position coordinates of the midpoint of the peak-to-peak distance between two symmetric waves is continuously within the threshold A three times. The coordinates (X n , Y n , Z n ) are regarded as the focal coordinates;

[0011] S6, One-dimensional sound pressure distribution scanning: Determine that the scanning interval length is D / 2, where D is the opening diameter of the transducer. The hydrophone moves and scans along the X-axis, Y-axis, and Z-axis respectively under the drive of the three-dimensional motion module. Among them, the scanning interval on the X-axis is [X n -D / 4:X n + D / 4, Y n , Z n , the scanning interval on the Y-axis is [X n , Y n -D / 4:Y n + D / 4, Z n , and the scanning interval on the Z-axis is [X n , Y n , Z n -D / 4:Z n + D / 4];

[0012] S7, Two-dimensional surface scanning: Determine that the scanning interval length is N / m, where N / m < D / 2. The hydrophone moves and scans along the XY plane, XZ plane, or YZ plane under the drive of the three-dimensional motion module. Among them, the scanning interval on the XY plane is [X n -N / (2m):X n + N / (2m), Y n -N / (2m):Y n + N / (2m), Z n , the scanning interval on the XZ plane is [X n -N / (2m):X n + N / (2m), Y n , Z n -N / (2m):Z n + N / (2m)], and the scanning interval on the YZ plane is [X n , Y n -N / (2m):Y n + N / (2m), Z n-N / (2m):Z n +N / (2m)], where m is a natural number greater than 1;

[0013] S8. Three-dimensional volume sound field scanning: The hydrophone performs volume scanning driven by the three-dimensional motion module, and the scanning range is [X n -N / (2m):X n +N / (2m),Y n -N / (2m):Y n +N / (2m),Z n -N / (2m):Z n +N / (2m)];

[0014] S9. End the scan;

[0015] In steps S2 - S8, the unit of the scanning range is mm.

[0016] The working principle and beneficial effects of this solution are as follows: First, in this solution, the focal length R of the transducer is known. The focal length R is input into the automatic control module, and the automatic control module preliminarily determines that the coordinates of the geometric focus F point of the transducer are (X0, Y0, Z0), without the need for manual visual prediction of the focus position coordinates of the transducer. Second, in this solution, from the start to the end of the measurement, the three-dimensional motion module is driven by the automatic system to move the hydrophone, realizing the automatic determination of the focus position coordinates of the transducer and the automatic measurement of the sound field, avoiding relying on manual exploration and continuous attempts, improving the efficiency of determining the focus position coordinates, and thus improving the measurement efficiency.

[0017] In summary, compared with the existing method of manually measuring the sound field, this solution realizes the automatic determination of the focus position coordinates of the transducer and the automatic measurement of the sound field. It is easy to operate, reduces the degree of manual participation, reduces the experience requirements for the operator, and improves the safety and measurement efficiency of the equipment.

[0018] Optionally, in step S1, according to the focal length R of the transducer, the length of the safe scanning range is set to P, where P is less than R; in steps S2 - S7, when the hydrophone moves beyond the safe scanning range [X0 - P / 2:X0 + P / 2, Y0, Z0] or [X0, Y0 - P / 2:Y0 + P / 2, Z0] or [X0, Y0, Z0 - P / 2:Z0 + P / 2], the automatic control module controls the three-dimensional motion module to brake.

[0019] In this solution, a safe scanning range is set. When the hydrophone moves beyond the safe scanning range, the automatic control module will control the three-dimensional motion module to brake, and the hydrophone stops moving, avoiding collisions between the hydrophone and the transducer or the side wall of the box, thus protecting the hydrophone and the transducer.

[0020] Optionally, an alarm module is provided on the automated control module or the three-dimensional motion module. When the hydrophone moves beyond the safe scanning range, the automated control module controls the alarm module to issue an alarm.

[0021] In this solution, when the hydrophone moves beyond the safe scanning range, while the hydrophone stops moving, the alarm module issues an alarm under the control of the automated control module, thereby warning the operator to adjust the length of the scanning range.

[0022] Optionally, in steps S7 and S8, according to the transducer, the corresponding -6 dB width d is selected. The coordinate of the hydrophone on the X-axis is set as X’, the coordinate on the Y-axis is set as Y’, and the coordinate on the Z-axis is set as Z’. When n -d ≤ X’ ≤ X n +d, or when Y n -d ≤ Y’ ≤ Y n +d, or when Z n -d ≤ Z’ ≤ Z n +d, the moving speed of the hydrophone is V1; when X’ < X n -d or X’ > X n +d, or when Y’ < Y n -d or Y’ > Y n +d, or when Z’ < Z n -d or Z’ > Z n +d, the moving speed of the hydrophone is V2, and V1 < V2.

[0023] In this solution, the automated control module controls the three-dimensional motion module to drive the hydrophone to perform variable-speed scanning work, so as to perform scanning work at speed V1 at the focal region (where the voltage signal value is strong), and perform scanning work at speed V2 at the non-focal region (where the voltage signal value is weak), avoiding always performing scanning work at speed V1 and further improving the measurement efficiency.

[0024] Optionally, during the process of X’ approaching X n or during the process of Y’ approaching Y n or during the process of Z’ approaching Z n , V1 gradually decreases; during the process of X’ moving away from X n or during the process of Y’ moving away from Y n or during the process of Z’ moving away from Z n V1 gradually increases..

[0025] In this solution, at the focal region, the closer the hydrophone is to the focus of the transducer, the lower the scanning speed of the hydrophone. In this way, the accuracy of the sound field measurement can be improved.

[0026] Optionally, during the process of X’ approaching X nDuring the process, or when Y’ is close to Y n During the process, or when Z’ is close to Z n During the process, V2 gradually decreases; when X’ is far from X n During the process, or when Y’ is far from Y n During the process, or when Z’ is far from Z n During the process, V2 gradually increases.

[0027] In this solution, at the non-focal region, the closer to the focus of the transducer, the lower the scanning speed of the hydrophone. Thus, the accuracy of sound field measurement can be improved.

[0028] Optionally, in step S6, the hydrophone is driven by the three-dimensional motion module to move along the X-axis, Y-axis, and Z-axis respectively for three consecutive scans. If the deviation of the focus voltage signal value is less than the threshold B, then enter step S7. If the deviation of the focus voltage signal value is greater than or equal to the threshold B, then return to step S5 to re-determine the focus coordinates.

[0029] In this solution, during the three consecutive scans on the X-axis, Y-axis, and Z-axis, if the deviation value of the focus voltage signal value is less than the threshold B, it indicates that the focus coordinates determined in step S5 are available. If the deviation of the focus voltage signal value is greater than or equal to the threshold B, it indicates that the focus coordinates determined in step S5 are not available, and it is necessary to return to step S5 to re-determine the focus coordinates, so as to ensure the accuracy of the transducer focus coordinates and further ensure the accuracy of sound field measurement.

[0030] Optionally, in step S5, A = 5%.

[0031] In this solution, A = 5% is appropriate, which is sufficient to ensure the accuracy of the transducer focus coordinates.

[0032] Optionally, in step S6, B = 10%.

[0033] In this solution, B = 10% is appropriate, which is sufficient to ensure the accuracy of the transducer focus coordinates.

[0034] Optionally, in step S5, when N / 2 - 10(n - 1) ≤ D / 4, the scanning interval of the X-axis is [X n-1 - D / 4:X n-1 + D / 4, Y n-1 , Z n-1 , the scanning interval of the Y-axis is [X n , Y n-1 - D / 4:Y n-1 + D / 4, Z n-1 , and the scanning interval of the Z-axis is [X n , Y n , Z n-1 - D / 4:Zn-1 +D / 4].

[0035] In this solution, the minimum value of a scanning range is set in step S5 to prevent the scanning range from becoming smaller and smaller, thereby ensuring that scanning results can be obtained for the X-axis, Y-axis, and Z-axis. Description of the Drawings

[0036] Figure 1 It is a schematic structural diagram of the automated sound field measurement device used in the automated sound field measurement method in Embodiment 1 of the present invention;

[0037] Figure 2 It is a flowchart of the automated sound field measurement method in Embodiment 1 of the present invention;

[0038] Figure 3 It is a schematic structural diagram of the automated sound field measurement device used in the automated sound field measurement method in Embodiment 2 of the present invention. Detailed Embodiments

[0039] The following is a more detailed description through specific embodiments:

[0040] The markings in the accompanying drawings of the specification include: automated control module 1, signal generator 2, power amplifier 3, focusing transducer 4, three-dimensional motion module 5, hydrophone 6, box body 7, and alarm module 8.

[0041] Embodiment 1

[0042] In this embodiment, an automated sound field measurement device is first provided. The device is as Figure 1As shown in the figure, it includes an automatic control module 1, a signal generator 2, a power amplifier 3, a focused transducer 4, a three-dimensional motion module 5, a hydrophone 6, and a box body 7. The box body 7 is filled with degassed water so that the experiment can be completed in the degassed water. The acquisition end of the hydrophone 6 and the probe of the focused transducer 4 are both located on the Z-axis (the acquisition end of the hydrophone 6 and the probe of the focused transducer 4 can also be located on the X-axis or Y-axis. In this embodiment, the Z-axis is taken as an example). The automatic control module 1, the signal generator 2, the power amplifier 3, and the focused transducer 4 are connected in sequence. The power amplifier 3 amplifies the output signal of the signal generator 2 and drives the focused transducer 4 to generate an acoustic field. The hydrophone 6 converts the collected acoustic wave signal into a voltage signal and transmits the voltage signal to the automatic control module 1. The three-dimensional motion module 5 can collect the position coordinate information of the hydrophone 6 in real time (for example, there is a distance sensor on the three-dimensional motion module 5 to monitor the position coordinates of the hydrophone 6 in the box body 7 in real time), and transmits the position coordinate information of the hydrophone 6 to the automatic control module 1. The automatic control module 1 controls the output of the signal generator 2, controls the power of the power amplifier 3, and controls the movement of the three-dimensional motion module 5 and stores data. The three-dimensional motion module 5 drives the hydrophone 6 to move in three-dimensional space (X-axis, Y-axis, Z-axis) under the control of the automatic control module 1. The hydrophone 6 collects the acoustic waves at the coordinate points in three-dimensional space, converts the collected acoustic wave signals into voltage signals, and transmits them to the automatic control module 1. The automatic control module 1 forms a waveform diagram after receiving the voltage signals at each coordinate to display the waveforms of the collected acoustic waves. Each coordinate point has its own three-dimensional space information. After the acoustic wave signal collected by the hydrophone 6 at the coordinate is converted into a voltage signal, it is transmitted to the automatic control module 1. After being processed by the operator, the sound pressure value is obtained. The sound pressure value and the three-dimensional coordinate information are in one-to-one correspondence and can be changed into a three-dimensional sound field. In this embodiment, the automatic control module 1 is a conventional known device such as a computer that plays a control role. The upper computer software used by the computer is the upper computer software of the three-dimensional sound field measurement system, English 3DUSPM (3Dimension UltraSound Pressure Mapping); the three-dimensional motion module 5 is an existing three-dimensional motion platform.

[0043] This embodiment also provides a method for automatically measuring a sound field, as Figure 2 shown, which specifically includes the following steps:

[0044] Step 1. Preliminary determination of the geometric focus coordinates of the transducer: Establish a transducer coordinate system. Assume that the acoustic axis of the focusing transducer 4 is coaxial with the Z-axis of the three-dimensional motion module 5. According to the focal length R of the focusing transducer 4, the operator inputs the parameter - focal length R into the automatic control module 1 (computer). The automatic control module 1 preliminarily determines that the geometric focus of the focusing transducer 4 is point F, and the coordinates of point F are (X0, Y0, Z0). The automatic control module 1 controls the three-dimensional motion module 5 to drive the hydrophone 6 to move to point F. Moreover, according to the focal length R of the focusing transducer 4, set the length of the safe scanning interval as P, where P is less than D. When the hydrophone 6 moves beyond the safe scanning interval [X0 - P / 2: X0 + P / 2, Y0, Z0] or [X0, Y0 - P / 2: Y0 + P / 2, Z0] or [X0, Y0, Z0 - P / 2: Z0 + P / 2], the automatic control module 1 controls the three-dimensional motion module 5 to brake to avoid the hydrophone 6 colliding with the focusing transducer 4 or the box body 7.

[0045] Step 2. X-axis scanning: Determine that the scanning interval length is N. The three-dimensional motion module 5 drives the hydrophone 6 to move and scan along the X-axis, and the scanning interval is [X0 - N / 2: X0 + N / 2, Y0, Z0]. The hydrophone 6 collects the voltage signals within this scanning interval, and the automatic control module 1 records the position coordinates (X1, Y0, Z0) of the maximum value of the voltage signal. In this step, if two symmetric Gaussian waveforms appear during the scanning process, at this time, select the trough position X1 between the two waves within the scanning interval (the position coordinate of the midpoint of the peak-to-peak distance of the two symmetric waves within the scanning interval) as the coordinate of the current focus reference position on the X-axis.

[0046] Step 3. Y-axis scanning: The three-dimensional motion module 5 drives the hydrophone 6 to move and scan along the Y-axis, and the scanning interval is [X1, Y0 - N / 2: Y0 + N / 2, Z0]. The hydrophone 6 collects the voltage signals within this scanning interval, and the automatic control module 1 records the position coordinates (X1, Y1, Z0) of the maximum value of the voltage signal. In this step, if two symmetric Gaussian waveforms appear during the scanning process, at this time, select the trough position Y1 between the two waves within the scanning interval (the position coordinate of the midpoint of the peak-to-peak distance of the two symmetric waves within the scanning interval) as the coordinate of the current focus reference position on the Y-axis.

[0047] Step 4. Z-axis scanning: The three-dimensional motion module 5 drives the hydrophone 6 to move and scan along the Z-axis, and the scanning interval is [X1, Y1, Z0 - N / 2: Z0 + N / 2]. The hydrophone 6 collects the voltage signals within this scanning interval, and the automatic control module 1 records the position coordinates (X1, Y1, Z1) of the maximum value of the voltage signal. In this step, if two symmetric Gaussian waveforms appear during the scanning process, at this time, select the trough position Z1 between the two waves within the scanning interval (the position coordinate of the midpoint of the peak-to-peak distance of the two symmetric waves within the scanning interval) as the coordinate of the current focus reference position on the Z-axis.

[0048] Step 5. Repeat Steps 2 to 4. During the repetition process, the scanning range of the X-axis is [X n-1 -N / 2 + 10(n - 1):X n-1 +N / 2 - 10(n - 1), Y n-1 , Z n-1 , and the automatic control module 1 records the position coordinates of the maximum value of the voltage signal or the position coordinates of the midpoint between the peaks of two symmetric waves (X n , Y n-1 , Z n-1 ). The scanning range of the Y-axis is [X n , Y n-1 -N / 2 + 10(n - 1):Y n-1 +N / 2 - 10(n - 1), Z n-1 , and the automatic control module 1 records the position coordinates of the maximum value of the voltage signal or the position coordinates of the midpoint between the peaks of two symmetric waves (X n , Y n , Z n-1 ). The scanning range of the Z-axis is [X n , Y n , Z n-1 -N / 2 + 10(n - 1):Z n-1 +N / 2 - 10(n - 1)], and the automatic control module 1 records the position coordinates of the maximum value of the voltage signal or the position coordinates of the midpoint between the peaks of two symmetric waves (X n , Y n , Z n ), where n successively takes positive integers greater than 1. Moreover, when N / 2 - 10(n - 1) ≤ D / 4 (D is the opening diameter of the focusing transducer 4), the scanning range of the X-axis is [X n-1 -D / 4:X n-1 +D / 4, Y n-1 , Z n-1 , the scanning range of the Y-axis is [X n , Y n-1 -D / 4:Y n-1 +D / 4, Z n-1 , and the scanning range of the Z-axis is [X n , Y n , Z n-1 -D / 4:Z n-1 +D / 4]. After that, the scanning range is no longer changed until the error of the position coordinates of the maximum value of the voltage signal collected by the hydrophone 6 on the X-axis, Y-axis, and Z-axis or the error of the position coordinates of the midpoint between the peaks of two symmetric waves is continuously within the threshold A three times. The coordinates (X n , Y n , Z n ) are regarded as the focal coordinates.

[0049] Specifically, in this step, when repeating Step 2 to Step 4 for the first time, n is taken as 2, the scanning range of the X-axis is [X1 - N / 2 + 10:X1 + N / 2 - 10, Y1, Z1], record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X2, Y1, Z1), the scanning range of the Y-axis is [X2, Y1 - N / 2 + 10:Y1 + N / 2 - 10, Z1], record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X2, Y2, Z1), and the scanning range of the Z-axis is [X2, Y2, Z1 - N / 2 + 10:Z1 + N / 2 - 10], record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X2, Y2, Z2).

[0050] When repeating Step 2 to Step 4 for the second time, n is taken as 3, the scanning range of the X-axis is [X2 - N / 2 + 20:X2 + N / 2 - 20, Y2, Z2], record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X3, Y2, Z2), the scanning range of the Y-axis is [X3, Y2 - N / 2 + 20:Y2 + N / 2 - 20, Z2], record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X3, Y3, Z2), and the scanning range of the Z-axis is [X3, Y3, Z2 - N / 2 + 20:Z2 + N / 2 - 20], record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X3, Y3, Z3).

[0051] When repeating Step 2 to Step 4 for the third time, n is taken as 4, after completing the scanning of the X-axis, Y-axis, and Z-axis, record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance between two symmetric waves (X4, Y4, Z4), and so on. When N / 2 - 10(n - 1) ≤ D / 4, the scanning range of the X-axis is [X n-1 - D / 4:X n-1 + D / 4,Y n-1 ,Z n-1 , the scanning range of the Y-axis is [X n ,Y n-1 - D / 4:Y n-1 + D / 4,Z n-1 , and the scanning range of the Z-axis is [X n ,Y n ,Z n-1 - D / 4:Z n-1+D / 4], and then the scanning range will no longer be changed until the coordinate error of the maximum value position of the voltage signal collected by the hydrophone 6 on the X-axis, Y-axis, and Z-axis or the coordinate error of the midpoint position between the wave crest spacings of two symmetric waves is continuously within the threshold of 5% three times. Then stop the scanning, and the automatic control module 1 records the coordinate of the maximum value position of the voltage signal or the midpoint position between the wave crest spacings of two symmetric waves (X n , Y n , Z n ), and this coordinate is regarded as the focal point coordinate of the focusing transducer 4.

[0052] Step Six: One-dimensional sound pressure distribution scanning: Determine that the scanning range length is D / 2 (D is the opening diameter of the focusing transducer 4). The hydrophone 6 is driven by the three-dimensional motion module 5 to move and scan continuously three times along the X-axis, Y-axis, and Z-axis respectively. Among them, the scanning range on the X-axis is [X n -D / 4:X n +D / 4, Y n , Z n , the scanning range on the Y-axis is [X n , Y n -D / 4:Y n +D / 4, Z n , and the scanning range on the Z-axis is [X n , Y n , Z n -D / 4:Z n +D / 4].

[0053] After scanning the X-axis, Y-axis, and Z-axis three times, if the deviation of the focal point voltage signal value of each axis is less than the threshold of 10%, then the one-dimensional sound pressure distribution scanning results of the X-axis, Y-axis, and Z-axis are obtained. If the deviation of the focal point voltage signal value of each axis is greater than or equal to 10%, then return to Step Five, continue scanning, re-determine the focal point coordinates, and then perform one-dimensional sound pressure distribution scanning until the deviation of the focal point voltage signal of each axis is less than 10%.

[0054] Step Seven: Two-dimensional plane scanning: Determine that the scanning range length is N / m, N / m < D / 2. The hydrophone 6 is driven by the three-dimensional motion module 5 to move and perform plane scanning along the XY plane or XZ plane or YZ plane. Among them, the scanning range on the XY plane is [X n -N / (2m):X n +N / (2m), Y n -N / (2m):Y n +N / (2m), Z n , and the scanning range on the XZ plane is [X n -N / (2m):X n +N / (2m), Y n , Z n-N / (2m):Z n +N / (2m)], the scanning range on the YZ plane is [X n , Y n -N / (2m):Y n +N / (2m), Z n -N / (2m):Z n +N / (2m)], obtaining the two-dimensional plane scanning results of the XY plane, XZ plane and YZ plane, where m is a natural number greater than 1.

[0055] In this step, according to the focusing transducer 4, the corresponding -6dB width d is selected, and the coordinates of the hydrophone 6 on the X-axis are set as X', the coordinates on the Y-axis are set as Y', and the coordinates on the Z-axis are set as Z'. When X n -d ≤ X' ≤ X n +d, or when Y n -d ≤ Y' ≤ Y n +d, or when Z n -d ≤ Z' ≤ Z n +d, the automatic control module 1 controls the moving speed of the three-dimensional motion module 5, thereby controlling the moving speed of the hydrophone 6 to be V1; when X' < X n -d or X' > X n +d, or when Y' < Y n -d or Y' > Y n +d, or when Z' < Z n -d or Z' > Z n +d, the automatic control module 1 controls the moving speed of the three-dimensional motion module 5, thereby controlling the moving speed of the hydrophone 6 to be V2, V1 < V2, the range of V1 is 60 - 70mm / s, and the range of V2 is 71 - 90mm / s. In this embodiment, V1 is 65mm / s and V2 is 85mm / s. Thus, the moving speed of the hydrophone 6 at the focal region is slower, and the moving speed at the non-focal region is faster, thereby improving the measurement efficiency on the premise of ensuring the accuracy of the measurement results.

[0056] In another embodiment, during the process of X' approaching X n , or during the process of Y' approaching Y n , or during the process of Z' approaching Z n , V1 gradually decreases from 70mm / s to 60mm / s; during the process of X' moving away from X n , or during the process of Y' moving away from Y n , or during the process of Z' moving away from Z n , V1 gradually increases from 60mm / s to 70mm / s; and, during the process of X' approaching X n , or during the process of Y' approaching Y n , or during the process of Z' approaching Zn During the process, V2 gradually decreases from 90 mm / s to 71 mm / s while X’ moves away from X n During the process, or while Y’ moves away from Y n During the process, or while Z’ moves away from Z n During the process, V2 gradually increases from 71 mm / s to 90 mm / s. In this way, the closer the hydrophone 6 is to the focal coordinates, the slower the moving speed (i.e., the scanning speed), which can better ensure the accuracy of the measurement results.

[0057] Step Eight: Three-dimensional volume sound field scanning: The hydrophone 6 performs volume scanning driven by the three-dimensional motion module 5, and the scanning range is [X n -N / (2m):X n +N / (2m),Y n -N / (2m):Y n +N / (2m),Z n -N / (2m):Z n +N / (2m)], and the three-dimensional volume sound field scanning result is obtained. m is a natural number greater than 1, and N / m < D / 2. Moreover, in this step, the motion speed setting of the hydrophone 6 is the same as that in Step Seven, so as to achieve automatic variable-speed scanning and improve the measurement efficiency.

[0058] Step Nine: End the scanning. The automatic control module 1 controls the three-dimensional motion module 5 to drive the hydrophone 6 to return to its original position. The operator calculates the sound pressure value based on the scanned voltage signal, thereby obtaining the one-dimensional sound pressure distribution, two-dimensional sound pressure surface, and three-dimensional volume sound field.

[0059] In Steps Two to Eight, the scanning range is in mm. In Steps Two to Six, the motion speed of the hydrophone 6 is 60 - 70 mm / s. In this embodiment, the motion speed of the hydrophone 6 in Steps Two to Six is 60 mm / s. In Steps Two to Eight, the scanning interval of the hydrophone 6 is 0.1 mm.

[0060] In Steps Two to Eight, when the hydrophone 6 moves beyond the safe scanning range [X0 - P / 2:X0 + P / 2, Y0, Z0] or [X0, Y0 - P / 2:Y0 + P / 2, Z0] or [X0, Y0, Z0 - P / 2:Z0 + P / 2], the automatic control module 1 controls the three-dimensional motion module 5 to brake, so that the hydrophone 6 stops moving, avoiding the collision of the hydrophone 6 with the focusing transducer 4 or the side wall of the box body 7, thereby protecting the hydrophone 6 and the focusing transducer 4 and improving the safety during the use of the equipment.

[0061] In this embodiment, the operator only needs to input the focal length R of the focusing transducer 4 used, as well as P, N, and m determined according to the opening diameter D of the focusing transducer, and select the corresponding -6dB width d according to the focusing transducer 4 before starting the measurement, so as to determine the length of each scanning interval and the safe scanning interval. That is, by pre-inputting several sets of appropriate parameters, the system will automatically preliminarily judge the coordinates (X0, Y0, Z0) of the geometric focus F point of the focusing transducer 4 and automatically determine the geometric focus coordinates (X n , Y n , Z n ) of the focusing transducer 4. Moreover, this embodiment can also achieve variable-speed scanning. Compared with the existing method of manually measuring the sound field, this embodiment is simple to operate, reduces the degree of manual participation, has low requirements for the operator's experience, realizes the automatic measurement of the sound field, improves the safety and measurement efficiency of the equipment, and ensures the accuracy of the sound field measurement.

[0062] Embodiment 2

[0063] The difference between this embodiment and Embodiment 1 is that, as Figure 3 shown, in this embodiment, an alarm module 8 is provided on the automatic control module 1. When the hydrophone 6 moves beyond the safe scanning interval, the automatic control module 1 controls the alarm module 8 to issue an alarm. The alarm module 8 includes an audible and visual alarm. When the hydrophone 6 moves beyond the safe scanning interval, the automatic control module 1 controls the audible and visual alarm to work and emit a sound signal and a light signal to warn the operator. The operator then re-enters the appropriate scanning interval length N and the appropriate scanning interval length N / m in the automatic control module 1.

[0064] The above are only embodiments of the present invention. The invention is not limited to the fields involved in this embodiment case. Common general knowledge such as the specific structures and characteristics known in the art are not described in detail here. Those of ordinary skill in the art know all the common general knowledge in the technical field to which the invention belongs before the filing date or the priority date, can know all the existing technologies in this field, and have the ability to apply the conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application, combine their own abilities to improve and implement this solution. Some typical known structures or known methods should not become an obstacle for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect and the practicality of the present invention. The protection scope required by this application should be based on the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to explain the content of the claims.

Claims

1. An automated method for measuring sound fields, characterized in that: Including the following steps: S1. Preliminary judgment of the geometric focus coordinates of the transducer: Establish a transducer coordinate system, where the acoustic axis of the transducer is coaxial with the X-axis or Y-axis or Z-axis. According to the focal length R of the transducer, the automation control module preliminarily determines that the geometric focus of the transducer is point F, and the coordinates of point F are (X0, Y0, Z0). The three-dimensional motion module drives the hydrophone to move to point F under the control of the automation control module; S2. X-axis scanning: Determine that the scanning interval length is N. The three-dimensional motion module drives the hydrophone to move and scan along the X-axis. The scanning interval is [X0 - N / 2: X0 + N / 2, Y0, Z0]. The hydrophone collects the voltage signals within this scanning interval and records the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance of two symmetric waves (X1, Y0, Z0); S3. Y-axis scanning: The three-dimensional motion module drives the hydrophone to move and scan along the Y-axis. The scanning interval is [X1, Y0 - N / 2: Y0 + N / 2, Z0]. The hydrophone collects the voltage signals within this scanning interval and records the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance of two symmetric waves (X1, Y1, Z0); S4. Z-axis scanning: The three-dimensional motion module drives the hydrophone to move and scan along the Z-axis. The scanning interval is [X1, Y1, Z0 - N / 2: Z0 + N / 2]. The hydrophone collects the voltage signals within this scanning interval and records the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance of two symmetric waves (X1, Y1, Z1); S5. Repeat steps S2 - S4. During the repetition process, the scanning range of the X-axis is [X n-1 -N / 2 + 10(n - 1):X n-1 +N / 2 - 10(n - 1), Y n-1 , Z n-1 . Record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance of two symmetric waves (X n , Y n-1 , Z n-1 ). The scanning range of the Y-axis is [X n , Y n-1 -N / 2 + 10(n - 1):Y n-1 +N / 2 - 10(n - 1), Z n-1 . Record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance of two symmetric waves (X n , Y n , Z n-1 ). The scanning range of the Z-axis is [X n , Y n , Z n-1 -N / 2 + 10(n - 1):Z n-1 +N / 2 - 10(n - 1)]. Record the position coordinates of the maximum value of the voltage signal or the midpoint position coordinates of the peak-to-peak distance of two symmetric waves (X n , Y n , Z n ). Among them, n successively takes positive integers greater than 1 until the error of the position coordinates of the maximum value of the voltage signal collected by the hydrophone on the X-axis, Y-axis, and Z-axis or the error of the midpoint position coordinates of the peak-to-peak distance of two symmetric waves is continuously within the threshold of 5% three times. The coordinates (X n , Y n , Z n ) are regarded as the focus coordinates; S6. One-dimensional sound pressure distribution scanning: Determine that the scanning interval length is D / 2, where D is the opening diameter of the transducer. The hydrophone moves and scans along the X-axis, Y-axis, and Z-axis respectively under the drive of the three-dimensional motion module. Among them, the scanning interval on the X-axis is [X n -D / 4:X n +D / 4,Y n ,Z n , the scanning interval on the Y-axis is [X n ,Y n -D / 4:Y n +D / 4,Z n , and the scanning interval on the Z-axis is [X n ,Y n ,Z n -D / 4:Z n +D / 4]; The hydrophone moves and scans continuously three times along the X-axis, Y-axis, and Z-axis respectively under the drive of the three-dimensional motion module. If the deviation of the focal voltage signal value is less than the threshold of 10%, then go to step S7. If the deviation of the focal voltage signal value is greater than or equal to the threshold of 10%, then return to step S5 to re-determine the focal coordinates; S7, Two-dimensional surface scanning: Determine that the scanning interval length is N / m, where N / m < D / 2. The hydrophone moves along the XY plane or XZ plane or YZ plane under the drive of the three-dimensional motion module for surface scanning. Among them, the scanning interval on the XY plane is [X n -N / (2m):X n +N / (2m),Y n -N / (2m):Y n +N / (2m),Z n , the scanning interval on the XZ plane is [X n -N / (2m):X n +N / (2m),Y n ,Z n -N / (2m):Z n +N / (2m)], and the scanning interval on the YZ plane is [X n ,Y n -N / (2m):Y n +N / (2m),Z n -N / (2m):Z n +N / (2m)], where m is a natural number greater than 1; S8. Three-dimensional volume sound field scanning: The hydrophone performs volume scanning under the drive of the three-dimensional motion module, and the scanning range is [X n -N / (2m):X n +N / (2m),Y n -N / (2m):Y n +N / (2m),Z n -N / (2m):Z n +N / (2m)]; S9. End the scanning; In steps S2 - S8, the unit of the scanning interval is mm.

2. The automated sound field measurement method according to claim 1, wherein: In step S1, according to the focal length R of the transducer, set the safe scanning interval length as P, and P is less than R. In steps S2 - S7, when the hydrophone moves beyond the safe scanning interval [X0 - P / 2: X0 + P / 2, Y0, Z0] or [X0, Y0 - P / 2: Y0 + P / 2, Z0] or [X0, Y0, Z0 - P / 2: Z0 + P / 2], the automation control module controls the three-dimensional motion module to brake.

3. The automated sound field measurement method according to claim 2, characterized in that: An alarm module is provided on the automation control module or the three-dimensional motion module. When the hydrophone moves beyond the safe scanning interval, the automation control module controls the alarm module to issue an alarm.

4. The automated sound field measurement method according to claim 1, characterized in that: In steps S7 and S8, according to the transducer, the corresponding -6 dB width d is selected, and the coordinates of the hydrophone on the X-axis are set as X', the coordinates on the Y-axis are set as Y', and the coordinates on the Z-axis are set as Z'. When X n -d ≤ X' ≤ X n + d, or when Y n -d ≤ Y' ≤ Y n + d, or when Z n -d ≤ Z' ≤ Z n + d, the moving speed of the hydrophone is V1; when X' < X n -d or X' > X n + d, or when Y' < Y n -d or Y' > Y n + d, or when Z' < Z n -d or Z' > Z n + d, the moving speed of the hydrophone is V2, and V1 < V2.

5. The automated sound field measurement method according to claim 4, characterized in that: During the process when X' approaches X n or during the process when Y' approaches Y n or during the process when Z' approaches Z n V1 gradually decreases; during the process when X' moves away from X n or during the process when Y' moves away from Y n or during the process when Z' moves away from Z n V1 gradually increases.

6. The automated sound field measurement method according to claim 4 or 5, characterized in that: During the process when X' approaches X n or during the process when Y' approaches Y n or during the process when Z' approaches Z n V2 gradually decreases; during the process when X' moves away from X n or during the process when Y' moves away from Y n or during the process when Z' moves away from Z n V2 gradually increases.

7. The automated sound field measurement method according to claim 1, characterized in that: In step S5, when N / 2 - 10(n - 1) ≤ D / 4, the scanning range of the X-axis is [X n-1 -D / 4:X n-1 +D / 4,Y n-1 ,Z n-1 , the scanning range of the Y-axis is [X n ,Y n-1 -D / 4:Y n-1 +D / 4,Z n-1 , and the scanning range of the Z-axis is [X n ,Y n ,Z n-1 -D / 4:Z n-1 +D / 4].

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