Methods, media, and devices for optimizing the power control of multibeam sounding sonar transmitting arrays

Abstract

This invention provides a method, medium, and apparatus for power optimization control of a multibeam bathymetry sonar transmitting array. The method includes: S1, obtaining the natural directivity of the transmitting array: designing a semi-cylindrical multibeam sonar transmitting array with N elements evenly spaced at angles and obtaining its natural array pattern P(θ); S2, generating a power optimization function based on the scattering loss distribution: assuming a scattering loss distribution of Q(θ) under a certain seabed medium, generating a power optimization function S(n) for different elements based on the scattering loss distribution Q(θ); S3, weighting the signals of each element of the transmitting array using the power optimization function S(n) to obtain an optimized pattern P2(θ), ensuring that this pattern P2(θ) can cancel out the scattering loss Q(θ), thereby achieving wide transmission coverage. This invention can achieve uniform echo signal energy in all directions, improving the sonar coverage range.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sonar, in particular to a multi-beam bathymetric sonar transmitting array power optimization control method, medium and device. BACKGROUND

[0002] Multi-beam bathymetric sonar is widely used in high-precision measurement of seabed topography. The coverage fan width is one of the key indicators of multi-beam bathymetric sonar, which reflects the mapping efficiency of the sonar in the horizontal direction, and its index is usually expressed as multiple water depths. Since the multiple water depth multiples that multi-beam bathymetric sonar can achieve in actual use are also affected by external factors such as seabed topography and hydrological environment, the sonar transmitting array-3dB beam width is also commonly used to represent this index.

[0003] The reasons affecting the coverage fan width of multi-beam bathymetric sonar mainly include two points:

[0004] 1) Directivity of the transmitting array. From the perspective of signal transmission alone, the larger the coverage range (-3dB beam width) of the transmitting array, the larger the coverage range of the transmitted acoustic signal.

[0005] 2) Seabed scattering of acoustic signals. Multi-beam bathymetric sonar detects the backscattering signal of the transmitted signal to measure the distance and depth. The larger the signal incidence angle, the greater the backscattering loss, and the weaker the echo signal, which is less conducive to detection.

[0006] To increase the coverage range, foreign similar products often use the following ways to optimize the transmitting array pattern, such as EM2040 and SeaBatT20-P, both of which have a double-probe transmitting mode, combining two probes into a V shape; FANSWEEP COASTAL 30 uses a U-shaped transmitting array to maximize the strength of the transmitted signal at the edge angle.

[0007] Some domestic patents have adopted similar ideas, such as domestic patent CN101149434B, which introduces a "multi-linear array combined acoustic array with super-wide coverage directivity", which is composed of two "V" shaped combined arrays. Each combined array is composed of multiple transmitting linear arrays and a receiving linear array, and the normal direction of the radiation surface of each transmitting linear array and the normal direction of the surface of the combined acoustic array have different angles, and the operating frequency of each transmitting linear array is optimized and selected (the farther the outside, the larger the angle, the higher the frequency), thereby increasing the echo energy of the outside seabed to improve the coverage range of the sonar.

[0008] There are also domestic patents considering using wide coverage array + phased mode to realize the optimal distribution of transmission energy. The domestic patent CN111025272A introduces a "flat acoustic array super wide coverage beam transmission method with tunnel effect inhibition capability", which uses two adjacent plane elements to transmit signals, one of which has a certain transmission delay relative to the other, thereby realizing signal beam control, making signal energy more distributed to the edge angle, realizing a wide coverage transmission beam with low central beam intensity and high two-side beam intensity.

[0009] The patent also mentions that if only the radiation beam intensity in each direction during transmission is considered to be the same, the seabed acoustic echo will be scattered strongly under the beam and weakly on both sides of the beam, causing the sidelobe of the receiving beam on the outside of the detection system to obtain stronger scattered signals than the main lobe, causing "tunnel effect" false depth measurement, which is a problem caused by the detection mechanism of the multi-beam depth sounding sonar.

[0010] As can be seen, in order to increase the coverage range of the multi-beam depth sounding sonar, only considering uniform coverage of the transmission signal at different angles is not enough, and the seabed scattering loss should also be considered to make the energy of the backscattered echo signal uniform in each direction. SUMMARY

[0011] The present application aims to provide a multi-beam depth sounding sonar transmission array power optimization control method, medium and device to realize uniform echo signal energy in all directions and improve the coverage range of the sonar.

[0012] The present application provides a multi-beam depth sounding sonar transmission array power optimization control method, which comprises the following steps:

[0013] S1, obtaining the natural directivity of the transmission array: designing an N-element equiangularly spaced half-cylindrical multi-beam sonar transmission array and obtaining its natural array pattern; setting the radius as r and the operating frequency as f, i.e. obtaining the pattern P(θ);

[0014] S2, generating a power optimization function in combination with the scattering loss distribution: assuming that the scattering loss distribution is Q(θ) under a certain seabed medium, generating a power optimization function S(n) for different elements according to the scattering loss distribution Q(θ);

[0015] S3, weighting the signals of each element of the transmission array through the power optimization function S(n) to obtain an optimized pattern P2(θ), and making the pattern P2(θ) able to cancel out the scattering loss Q(θ), so as to realize transmission wide coverage.

[0016] Further, step S2 comprises the following sub-steps:

[0017] S21, input the scattering loss distribution Q(θ);

[0018] S22, data processing is performed on the input scattering loss distribution Q(θ) to obtain Q'(θ);

[0019] S23, the power optimization function S(n) of different elements is generated by using Q'(θ).

[0020] Further, the step S22 comprises the following sub-steps:

[0021] S221, from the scattering loss distribution Q(θ), the scattering loss distribution values in the angle range corresponding to the directional diagram of the transmitting array are intercepted according to the coverage angle of the transmitting array;

[0022] S222, from the scattering loss distribution values intercepted in the step S221, the corresponding scattering loss distribution values are selected according to the characteristics of the seabed medium in actual use;

[0023] S223, the scattering loss distribution values selected in the step S222 are normalized to obtain Q'(θ).

[0024] Further, in the step S222, if the seabed medium is not determined, the average value of the scattering loss distribution values of multiple seabed media is used.

[0025] Further, the step S23 comprises the following sub-steps:

[0026] S231, the reciprocal of Q'(θ) is obtained to obtain R(θ);

[0027] S232, R'(θ) is obtained by normalizing R(θ);

[0028] S233, the weighting coefficient is set according to the influence of the difference of the transmitting signal amplitudes between different channels on the transmitting power amplifier during engineering application, and R"(θ) is obtained by scaling R'(θ) by using the weighting coefficient;

[0029] S234, the power optimization function S(n) is obtained by equally spacing sampling R"(θ), and the total number of samples after extraction is the number N of transmitting elements.

[0030] Further, in the step S232, R'(θ) obtained by normalizing R(θ) is expressed as: R'(θ) = R(θ) / max(R(θ)).

[0031] Further, in the step S233, the value range of the weighting coefficient is [0.1, 1].

[0032] Further, scaling R'(theta) in step S233 by using the weighting coefficient to obtain R''(theta) is expressed as: R''(theta)=0.9x[R'(theta)-min(R'(theta))] / [1-min(R'(theta))]+0.1.

[0033] The application further provides a computer terminal storage medium, which stores computer terminal executable instructions for executing the multi-beam bathymetric sonar transmitting array power optimization control method.

[0034] The application further provides a computing device, which comprises:

[0035] at least one processor; and a memory connected with the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the multi-beam bathymetric sonar transmitting array power optimization control method.

[0036] In summary, due to the adoption of the above technical solutions, the application has the following beneficial effects:

[0037] The application produces a transmitting directivity pattern which can be opposite to the scattering loss by weighting the transmitting signals of each element of the semi-cylindrical multi-beam sonar transmitting array, and then realizes uniform energy at different angles at the receiving end. The main advantages are as follows:

[0038] 1. Under the condition of certain transmitting power, the application expands the detection distance of the seabed in the direction of large incident angle by optimizing the power distribution, and increases the coverage range of the multi-beam bathymetric sonar.

[0039] 2. The application can weaken the influence of the "tunnel effect" depth sounding false image of the multi-beam bathymetric sonar on the depth sounding result, and can simplify the complexity of the depth sounding algorithm and improve the effectiveness of the depth sounding result. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings in the embodiments will be briefly introduced as follows, and it should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation to the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of the drawings.

[0041] Figure 1 The flow chart of the multi-beam bathymetric sonar transmitting array power optimization control method in the embodiments of the application.

[0042] Figure 2 The element distribution diagram of the transmitting array in the embodiments of the application.

[0043] Figure 3 Figure 9 is a natural array pattern diagram of a transmitting array in an embodiment of the present application.

[0044] Figure 4 Figure 10 is a scattering loss distribution diagram of several typical seabed media in an embodiment of the present application.

[0045] Figure 5 Figure 11 is a normalized scattering loss distribution diagram in an embodiment of the present application.

[0046] Figure 6 Figure 12 is a power optimization function distribution diagram in an embodiment of the present application.

[0047] Figure 7 Figure 13 is an optimized pattern diagram in an embodiment of the present application.

[0048] Figure 8 Figure 14 is a normalized amplitude distribution diagram of echo signals of different angles in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0051] EMBODIMENT

[0052] As shown in Figure 1 the present embodiment proposes a multi-beam sounding sonar transmitting array power optimization control method, which comprises the following steps:

[0053] S1, obtaining a natural directivity of a transmitting array: designing a half-cylindrical multi-beam sonar transmitting array with N elements distributed at equal angles and obtaining a natural array pattern diagram thereof; setting a radius as r and a working frequency as f, i.e. obtaining a pattern diagram P(θ);

[0054] In the present embodiment, as Figure 2As shown, the number of elements N of the transmitting array is designed to be 15, the radius r is 30 mm, and the operating frequency f is 200 kHz. Only the coverage range of 120 degrees (±60°) of the array is considered, and the natural array directivity pattern P(θ) thereof is obtained as Figure 3 As shown, the amplitude difference of the transmitting array within the range of ±60° is not more than 3 dB.

[0055] S2, combine the scattering loss distribution to generate the power optimization function: assuming that the scattering loss distribution is Q(θ) under a certain seabed medium, the power optimization function S(n) of different elements is generated according to the scattering loss distribution Q(θ):

[0056] S21, input the scattering loss distribution Q(θ); the scattering loss of the transmitted acoustic signal is related to the type of seabed medium, the signal incidence angle, and the signal frequency. Under the operating frequency and the type of seabed medium, the scattering loss distribution at different angles can be expressed as a function Q(θ). The backscattering loss distribution functions of several typical seabed media are as shown in Figure 4 The value is input externally or measured in the field. According to the distribution characteristics of the scattering loss distribution function Q(θ), it is obvious that Q(θ) is an even function, i.e., Q(θ) = Q(-θ).

[0057] S22, perform data processing on the input scattering loss distribution Q(θ) to obtain Q'(θ):

[0058] S221, from the scattering loss distribution Q(θ), the scattering loss distribution values in the angle range corresponding to the directivity pattern of the transmitting array are intercepted according to the coverage angle of the transmitting array; in the foregoing, the scattering loss distribution values in the range of ±60° are selected in the embodiment.

[0059] S222, from the scattering loss distribution values intercepted in step S221, the corresponding scattering loss distribution values are selected according to the characteristics of the seabed medium in actual use; optionally, if the seabed medium is not determined, the average value of the scattering loss distribution values of multiple seabed media is used. In the embodiment, the average value of the scattering loss distribution values of multiple seabed media is used.

[0060] S223, since only the relative size of the scattering loss at different angles needs to be considered, the scattering loss distribution values selected in step S222 are normalized to obtain Q'(θ) as shown in Figure 5

[0061] S23, generate the power optimization function S(n) of different elements using Q'(θ):

[0062] S231, obtain R(θ) by taking the inverse of Q'(θ), i.e., R(θ) = 1 / Q'(θ);

[0063] ​S232, normalizing R(0) to obtain R'(0), R'(0)=R(0) / max(R(0));

[0064] S233, setting a weighting coefficient according to the influence of the difference of the transmit signal amplitudes between different channels on the transmit power amplifier during engineering application, and scaling R'(0) by using the weighting coefficient to obtain R"(0); wherein, considering that the difference of the transmit signal amplitudes between different channels should not be too large to affect the design of the transmit power amplifier during engineering application, in this embodiment, the difference of the amplification multiples between different channels is considered to be no more than 10 times, that is, the weighting coefficient is taken to be between 0.1 and 1, then R'(0) is scaled to obtain R"(0)=0.9x[R'(0)-min(R'(0))] / [1-min(R'(0))]+0.1.

[0065] S234, sampling R"(0) at equal intervals to obtain a power optimization function S(n), and the total number of samples after sampling is the number N of transmit elements. Corresponding to the foregoing, in this embodiment, the total number of samples after sampling is 15, and the power optimization function S(n) obtained by sampling is as shown in Figure 6 .

[0066] S3, weighting the signals of the transmit array elements by using the power optimization function S(n) to obtain an optimized directivity pattern P2(0), as shown in Figure 7 . Figure 8 . It can be seen that, at the receiving end, the echo signal intensity distribution at each angle is basically within-3dB of the maximum amplitude. That is, by optimizing the directivity pattern and the scattering loss Q(0), the uniform distribution of the echo signal power is achieved, so as to achieve wide coverage for seabed measurement.

[0067] In addition, in some embodiments, a computer terminal storage medium is provided, which stores computer terminal executable instructions for executing the multi-beam bathymetric sonar transmit array power optimization control method as described in the foregoing embodiments. Examples of the computer storage medium include magnetic storage media (for example, floppy disks, hard disks, etc.), optical recording media (for example, CD-ROM, DVD, etc.), or memories such as memory cards, ROMs or RAMs, etc. The computer storage medium can also be distributed on network-connected computer systems, for example, an application store.

[0068] Furthermore, in some embodiments, a computing device is proposed, comprising at least one processor; and a memory communicatively connected with the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions are executed by the at least one processor to enable the at least one processor to perform the multi-beam bathymetric sonar transmit array power optimization control method as described in the foregoing embodiments. Examples of the computing device include a PC, a tablet computer, a smartphone, a PDA, and the like.

[0069] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for optimizing the power control of a multi-beam sounding sonar transmitting array, characterized in that, Comprising the following steps: S1, obtaining natural directivity of transmitting array: design N A half-cylinder multi-beam sonar transmitting array with elements equally spaced is designed and its natural array pattern is obtained; let the radius be r , and the working frequency be f , then the pattern P ( θ ) is obtained. S2, combine the scattering loss distribution to generate the power optimization function: assuming that the scattering loss distribution is Q( θ ) under the condition of a certain seabed medium, the power optimization function S( n ) of different primitives is generated according to the scattering loss distribution Q( θ ); S3, the power optimization function S( n ) is used to weight the signals of each element of the transmitting array, so as to obtain an optimized directivity pattern P 2( θ ), and the directivity pattern P 2( θ ) can be used to cancel the scattering loss Q( θ ), so as to realize the wide coverage of the transmission. Step S2 comprises the following sub-steps: S21, input scattering loss distribution Q θ ); S22, data processing is performed on the input scattering loss distribution Q( θ ) to obtain Q'( θ ); S23, generating power optimization functions S( θ ) for different primitives using Q'( n ); Step S22 comprises the following sub-steps: S221, from the scattering loss distribution Q( θ ), according to the coverage angle of the transmitting array, intercept the scattering loss distribution values in the angle range corresponding to the transmitting array directional diagram. S222, from the scattering loss distribution value intercepted in step S221, according to the characteristics of the seabed medium in actual use, select the corresponding scattering loss distribution value; S223, normalizing the scattering loss distribution value selected in step S222 to obtain Q'( θ ); Step S23 comprises the following sub-steps: S231, the inverse of Q'( θ ) is taken to get R( θ ). S232, normalizing R( θ ) to obtain R'( θ ); S233, a weighting coefficient is set according to the influence of the difference in transmitted signal amplitude between different channels on the transmitting power amplifier in engineering applications, and the weighting coefficient is used to adjust R'( θ ) is scaled to obtain R''( θ ); S234, R''( θ ) is equally spaced sampling to get the power optimization function S( n ), the total number of samples after extraction is the number of transmission elements N.

2. The method of claim 1, wherein, In step S222, if the seabed medium is not determined, the average value of the scattering loss distribution values of multiple seabed media is used.

3. The method of claim 1, wherein, In step S232, for R( θ R'( ) is obtained by normalization θ ) is represented as: R'( θ )=R( θ ) / max(R( θ )).

4. The method of claim 1, wherein, The weighting coefficient set in step S233 is in the range of [0.1, 1].

5. The method of claim 4, wherein, R''( θ ) is obtained by scaling R'( θ ) in step S233 using a weighting factor, and is expressed as: R''( θ )=0.9×[R'( θ )-min(R'( θ ))] / [1-min(R'( θ ))]+0.

1.

6. A computer terminal storage medium storing computer terminal executable instructions, characterized in that, The computer terminal executable instructions are used to execute the multi-beam bathymetric sonar transmitting array power optimization control method as claimed in any one of claims 1-5.

7. A computing device, comprising: Comprising: At least one processor; And a memory connected in communication with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the multi-beam bathymetric sonar transmitting array power optimization control method as claimed in any one of claims 1-5.

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