Sonar background noise simulation modeling method and system based on measured data

Abstract

The invention relates to a sonar background noise simulation modeling method and system based on measured data, and the method comprises the following steps: S1, building a sonar background noise simulation calculation model according to different sonar types; s2, acquiring a sound array space sound field and vibration distribution; the sound array space sound field and the vibration distribution condition comprise background noise data received by the sound array and background noise data measured by sensors around the sound array; and S3, calculating transfer functions, including a vibration-sound transfer function and a sound-sound transfer function, according to a simulation model established according to the sound array space sound field and the vibration distribution data obtained in the step S2. The sonar background noise can be accurately and comprehensively forecasted, and a technical basis is provided for a comprehensive suppression scheme of the sonar background noise.

Description

Technical field:

[0001] The invention belongs to the field of acoustic technology, and in particular relates to a sonar background noise simulation modeling method and system based on measured data. Background technology:

[0002] The detection capability of sonar depends not only on the technical performance of the sonar equipment itself, but also on the background noise in its working environment. The background noise of the bow sonar is mainly the acoustic interference of the structure inside and around the guidance dome. These acoustic interferences will directly affect the detection performance of the sonar, reduce the signal-to-noise ratio of the sonar receiving system, destroy the beam forming, make the detection distance closer, and reduce the accuracy. The composition of sonar background noise is relatively complex. According to the source of noise, it can be generally divided into four categories, including mechanical noise, hydrodynamic noise, propeller noise and marine environmental noise. Among them, the difference between marine environmental noise and the other three noises is more than 10dB. This noise component is usually ignored. Therefore, the prediction of sonar flat background noise mainly refers to the simulation modeling of mechanical noise, hydrodynamic noise and propeller noise.

[0003] The existing simulation methods of sonar flat background noise mainly establish these three noise models separately. The simulation method of mechanical noise is to establish an acoustic-solid coupling model by applying mechanical excitation for prediction. There is a large gap between its mechanical excitation source and the actual vibration source. The simulation method of hydrodynamic noise is to establish an acoustic radiation model by simulating the flow field and calculating the pulsating pressure. The hydrodynamic noise often requires huge computing resources and energy when calculating the flow field. The prediction of propeller noise is mainly based on the calculation of the radiated sound field based on the fluid-solid coupling model. When the propeller noise propagates to the bow fairing, there are multiple transmission paths, resulting in poor calculation accuracy. In other words, the existing simulation calculation method uses empirical or single input conditions when establishing the sonar background noise prediction model. It can only simulate and calculate one of the mechanical noise, hydrodynamic noise, and propeller noise in the sonar background noise, and it cannot match the actual test conditions, so that the established sonar background noise prediction model is far from the actual situation, and it is impossible to accurately establish a sonar background noise model that conforms to the actual situation. Summary of the invention:

[0004] The technical problem to be solved by the present invention is to provide a sonar background noise simulation modeling method and system based on measured data. The method inverts the noise source of the sonar background noise based on the measured data, establishes an excitation source and a sound source under actual working conditions, and simulates and calculates the sonar background noise by inputting the noise source conditions to achieve accurate and comprehensive prediction of the sonar background noise, thereby providing a technical basis for a comprehensive suppression solution for the sonar background noise.

[0005] The technical solution of the present invention is to provide a sonar background noise simulation modeling method based on measured data, comprising the following steps:

[0006] S1: Construct a sonar background noise simulation calculation model according to different sonar types;

[0007] S2: Acquire the sound field and vibration distribution of the acoustic array space; the sound field and vibration distribution of the acoustic array space include the background noise data received by the acoustic array and the background noise data measured by sensors around the acoustic array;

[0008] S3: Calculate the transfer function of the simulation model established according to the spatial sound field and vibration distribution data of the acoustic array obtained in step S2, including the vibration-acoustic transfer function and the acoustic-acoustic transfer function;

[0009] S4: Infer the noise source and vibration source based on the measured data;

[0010] S5: Input the sonar background noise field calculated by inverting the noise source and vibration source.

[0011] The present invention inversely infers the noise source of sonar background noise based on measured data. Since the measured data is information generated by the common superposition of multiple noise sources, the noise source includes all information sources of mechanical noise, hydrodynamic noise, and propeller noise in the sonar background noise. By inputting the inverted noise source conditions, the comprehensive sonar background noise including mechanical noise, hydrodynamic noise, and propeller noise can be simulated and calculated to achieve a comprehensive and accurate prediction of the sonar background noise, providing a technical basis for a comprehensive suppression scheme of the sonar background noise.

[0012] Preferably, the specific operations of step S1 are as follows:

[0013] Step S1.1, establish a sonar simulation calculation model according to the hull line shape. For sonars in different positions such as the bow acoustic array, the side array, and the towed array, it is only necessary to establish adjacent related regional transfer cabins or structures.

[0014] Step S1.2, simplifying the structure and dividing the discretized grid according to the grid requirements;

[0015] Step S1.3, assign material properties to all panels according to different cabin structures and connection types.

[0016] Preferably, step S2 is specifically performed as follows:

[0017] Step S2.1, four hydrophones are arranged at intervals of 90 degrees in the circumferential position of the acoustic array, and three circles of hydrophones are arranged in the height direction of the acoustic array according to the requirement of three equal divisions, for a total of 12 hydrophones; a total of 26 accelerometers are arranged at the connection positions of the upper and lower surfaces of the acoustic array, which are evenly divided into twelve equal parts;

[0018] Step S2.2, connect all the hydrophone and accelerometer receiving signals to the acquisition system and collect them;

[0019] Step S2.3, simultaneously collect the real-time experimental data received by the acoustic array.

[0020] Preferably, step S3 is specifically performed as follows:

[0021] Step S3.1, determining the calculation frequency range of the transfer function according to the working frequency band of the acoustic array;

[0022] Step S3.2, establishing load loading positions in the simulation calculation model, wherein the force load is established at the center position of the rear wall panel connecting the cabin, and the acoustic load is established at the center position of the stern cabin;

[0023] Step S3.3, by applying unit force excitation in the simulation calculation model, the internal sound field S1(f) of the simulation model is calculated. According to the linear system theory, S1(f) is the vibration-acoustic transfer function of the simulation model.

[0024] Step S3.4, by applying unit sound wave excitation in the simulation calculation model, the internal sound field S2(f) of the simulation model is calculated. According to the linear system theory, S2(f) is the sound-to-sound transfer function of the simulation model.

[0025] Preferably, step S4 is specifically performed as follows:

[0026] Step S4.1, using the vibroacoustic response data collected by the hydrophones and accelerometers arranged at the circumferential positions and the upper and lower surfaces of the acoustic array as the response output of the linear system;

[0027] Step S4.2, establishing a vibroacoustic coupling equation according to the vibration-acoustic transfer function S1(f) and the acoustic-acoustic transfer function S2(f) and the above-mentioned response output;

[0028] Step S4.3, by solving the above acoustic-vibration coupling equation, the excitation source of this linear system is obtained, and the excitation source is the vibration source and the noise source.

[0029] Preferably, step S5 is specifically performed as follows:

[0030] Step S5.1, according to the noise source and vibration source obtained, which are the noise source and vibration source under the actual working condition, they are substituted into the transfer function of the simulation calculation model, and the background noise under the actual working condition can be calculated by solving the acoustic-vibration coupling equation;

[0031] Step S5.2, comparing the calculated sound field result inside the bow fairing with the measured data. If the obtained sound field result is highly similar to the measured data, the sonar background noise simulation modeling method based on the measured data is correct.

[0032] The present invention also provides a system using the sonar background noise simulation modeling method based on measured data, the system comprising:

[0033] The simulation model building module builds the simulation calculation model according to the structural line diagram;

[0034] The experimental test module collects vibration and acoustic field data according to the sensor layout, and the noise source inversion module inverts the vibration source and noise source according to the vibration-acoustic transfer function and the acoustic-acoustic transfer function combined with the measured data;

[0035] The sonar background noise field calculation module calculates the sonar background noise field based on the inverted vibration source and noise source combined with the transfer function.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] The present invention inverts the noise source based on the transfer function inferred from the measured data to calculate the background noise of the sonar platform, avoids the complicated acoustic-solid coupling and fluid-solid coupling solution methods, effectively saves a large amount of software and hardware computing resources, and calculates the superimposed sound field of multiple sound sources in the platform background noise in a simulation model, which solves the defect that only one type of background noise can be solved in the existing simulation technology, greatly improves the efficiency of sonar background noise modeling, and provides a solid technical foundation for the subsequent comprehensive suppression plan of sonar background noise. Description of the drawings:

[0038] Figure 1 It is a schematic diagram of the process of the present invention.

[0039] Figure 2 This is a sonar background noise simulation calculation model of an embodiment of the present invention.

[0040] Figure 3 It is the vibration source inverted in the embodiment of the present invention.

[0041] Figure 4 It is the noise source inverted by the embodiment of the present invention.

[0042] Figure 5 The sonar background noise calculation result of the embodiment of the present invention. Specific implementation method:

[0043] The present invention will be further described below with reference to the accompanying drawings:

[0044] A sonar background noise simulation modeling method based on measured data is used to achieve a comprehensive and accurate prediction of sonar background noise. The method flow of the present invention is as follows Figure 1 To achieve the above-mentioned purpose, the technical solution of the present invention comprises the following steps:

[0045] 1. Construct a sonar background noise simulation calculation model; this embodiment takes the bow sonar as an example to illustrate, and specifically includes the following steps:

[0046] 1.1 According to the hull line shape, the bow sonar simulation calculation model is established, including the shroud acoustic cavity, the stern water tank, the air chamber, the upper air chamber of the shroud and the acoustic array model. Figure 2 As shown;

[0047] 1.2 Simplify the structure and divide the discretized grid according to the grid requirements;

[0048] 1.3 Assign material properties to all panels according to different cabin structures and connection types;

[0049] 2. Obtain the spatial sound field and vibration distribution of the sound array; specifically including the following steps

[0050] 2.1 Four hydrophones are arranged at intervals of 90 degrees around the acoustic array, and three circles of hydrophones are arranged in the height direction of the acoustic array in accordance with the requirement of three equal divisions, for a total of 12 hydrophones; a total of 26 accelerometers are arranged at twelve equal parts of the upper and lower surfaces of the acoustic array and at the connection positions;

[0051] 2.2 Connect all hydrophone and accelerometer receiving signals to the acquisition system and collect them;

[0052] 2.3 Simultaneously collect real-time experimental data received by the acoustic array;

[0053] The spatial sound field and vibration distribution of the acoustic array obtained at this time include the background noise data received by the acoustic array and the background noise data measured by the sensors around the acoustic array; in this embodiment, the measured data in the bow fairing, including the signal data received by the acoustic array, the recording data of the hydrophone in the fairing, the vibration signal data of the accelerometer on the acoustic array, etc.

[0054] 3. Calculate the transfer function based on the established simulation model, which includes the following steps:

[0055] 3.1 Define the calculation frequency range of the transfer function according to the working frequency band of the acoustic array;

[0056] 3.2 Establish load loading positions in the simulation calculation model. In this embodiment, the force load is established at the center of the rear wall panel connecting the cabin, and the acoustic load is established at the center of the stern cabin;

[0057] 3.3 The internal sound field S1(f) of the simulation model is calculated by applying unit force excitation in the simulation calculation model. According to the linear system theory, S1(f) is the vibration-acoustic transfer function of the simulation model.

[0058] 3.4 The internal sound field S2(f) of the simulation model is calculated by applying unit sound wave excitation in the simulation calculation model. According to the linear system theory, S2(f) is the sound-to-sound transfer function of the simulation model.

[0059] 4. Infer the noise source and vibration source based on the measured data; Figure 3 , 4 As shown, the specific steps include the following steps

[0060] 4.1 The vibroacoustic response data collected by the hydrophones and accelerometers arranged at the circumferential positions and upper and lower surfaces of the acoustic array are used as the response output of the linear system;

[0061] 4.2 Establish the acoustic-vibration coupling equation according to the vibration-acoustic transfer function S1(f) and the acoustic-acoustic transfer function S2(f) and the above response output;

[0062] 4.3 By solving the above acoustic-vibration coupling equation, the excitation source of this linear system, namely the vibration source and noise source, can be obtained.

[0063] That is, the noise source and vibration source of the bow fairing simulation calculation model are inverted using the transfer function according to the measured data;

[0064] 5. Input the sonar background sound field obtained by inversion of noise source and vibration source calculation; specifically including the following steps

[0065] 5.1 The noise source and vibration source obtained according to the above steps are the noise source and vibration source under the actual working conditions. Substituting the transfer function of the simulation calculation model into the background noise under the actual working conditions can be calculated by solving the acoustic-vibration coupling equation, such as Figure 5 .

[0066] 5.2. Compare the calculated sound field results inside the bow fairing with the measured data. If the obtained sound field results are highly similar to the measured data, the sonar background noise simulation modeling method based on the measured data is correct.

[0067] The present invention also provides a system using the sonar background noise simulation modeling method based on measured data, the system comprising:

[0068] The simulation model building module builds the simulation calculation model according to the structural line diagram;

[0069] The experimental test module collects vibration and acoustic field data according to the sensor layout, and the noise source inversion module inverts the vibration source and noise source according to the vibration-acoustic transfer function and the acoustic-acoustic transfer function combined with the measured data;

[0070] The sonar background noise field calculation module calculates the sonar background noise field based on the inverted vibration source and noise source combined with the transfer function.

[0071] The invention inverts the noise source of sonar background noise based on measured data, establishes an excitation source and a sound source under actual working conditions, and calculates the sonar background noise by simulating the input noise source conditions to achieve accurate and comprehensive prediction of the sonar background noise, thereby providing a technical basis for a comprehensive suppression scheme for sonar background noise.

[0072] The above is only an explanation of the preferred embodiments of the present invention, which should not be construed as a limitation on the claims. Any equivalent process changes made using the present invention specification are included in the patent protection scope of the present invention.

Claims

1. A sonar background noise simulation modeling method based on measured data, characterized in that: The following steps are included: S1: Construct a sonar background noise simulation calculation model according to different sonar types; S2: Acquire the sound field and vibration distribution of the acoustic array space; the sound field and vibration distribution of the acoustic array space include the background noise data received by the acoustic array and the background noise data measured by sensors around the acoustic array; S3: Calculate the transfer function of the simulation model established according to the spatial sound field and vibration distribution data of the acoustic array obtained in step S2, including the vibration-acoustic transfer function and the acoustic-acoustic transfer function; S4: Inversely infer the noise source and vibration source based on the measured data; S5: Input the sonar background noise field calculated by inverting the noise source and vibration source.

2. The sonar background noise simulation modeling method based on measured data according to claim 1 is characterized in that: The specific operations of step S1 are as follows: Step S1.1, establishing a sonar simulation calculation model according to the hull line shape, and establishing adjacent related regional transfer cabins or structures for sonars at different positions; Step S1.2, simplifying the structure and dividing the discretized grid according to the grid requirements; Step S1.3, assign material properties to all panels according to different cabin structures and connection types.

3. The sonar background noise simulation modeling method based on measured data according to claim 1 is characterized in that: The specific operation of step S2 is as follows: Step S2.1, four hydrophones are arranged at intervals of 90 degrees in the circumferential position of the acoustic array, and three circles of hydrophones are arranged in the height direction of the acoustic array according to the requirement of three equal divisions, for a total of 12 hydrophones; a total of 26 accelerometers are arranged at the connection positions of the upper and lower surfaces of the acoustic array, which are evenly divided into twelve equal parts; Step S2.2, connect all the hydrophone and accelerometer receiving signals to the acquisition system and collect them; Step S2.3, simultaneously collect the real-time experimental data received by the acoustic array.

4. The sonar background noise simulation modeling method based on measured data according to claim 1 is characterized in that: The specific operation of step S3 is as follows: Step S3.1, determining the calculation frequency range of the transfer function according to the working frequency band of the acoustic array; Step S3.2, establishing load loading positions in the simulation calculation model, wherein the force load is established at the center position of the rear wall panel connecting the cabin, and the acoustic load is established at the center position of the stern cabin; Step S3.3, by applying unit force excitation in the simulation calculation model, the internal sound field S1(f) of the simulation model is calculated, and at this time S1(f) is the vibration-acoustic transfer function of the simulation model; Step S3.4, by applying unit sound wave excitation in the simulation calculation model, the internal sound field S2(f) of the simulation model is calculated. At this time, S2(f) is the sound-to-sound transfer function of the simulation model.

5. The sonar background noise simulation modeling method based on measured data according to claim 1 is characterized in that: The specific operation of step S4 is as follows: Step S4.1, using the vibroacoustic response data collected by the hydrophones and accelerometers arranged at the circumferential positions and the upper and lower surfaces of the acoustic array as the response output of the linear system; Step S4.2, establishing a vibroacoustic coupling equation according to the vibration-acoustic transfer function S1(f) and the acoustic-acoustic transfer function S2(f) and the above-mentioned response output; Step S4.3, by solving the above acoustic-vibration coupling equation, the excitation source of this linear system is obtained, and the excitation source is the vibration source and the noise source.

6. The sonar background noise simulation modeling method based on measured data according to claim 1 is characterized in that: The specific operation of step S5 is as follows: Step S5.1, according to the acquired noise source and vibration source, substitute them into the transfer function of the simulation calculation model, and calculate the background noise under the actual working conditions by solving the acoustic-vibration coupling equation; Step S5.2, comparing the calculated sound field result inside the bow fairing with the measured data. If the obtained sound field result is highly similar to the measured data, the sonar background noise simulation modeling method based on the measured data is correct.

7. A system using the sonar background noise simulation modeling method based on measured data according to any one of claims 1 to 6, characterized in that: include, The simulation model building module builds the simulation calculation model according to the structural line diagram; The experimental test module collects vibration and acoustic field data according to the sensor layout, and the noise source inversion module inverts the vibration source and noise source according to the vibration-acoustic transfer function and the acoustic-acoustic transfer function combined with the measured data; The sonar background noise field calculation module calculates the sonar background noise field based on the inverted vibration source and noise source combined with the transfer function.

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