A sonar background noise simulation modeling method and system based on measured data

Abstract

The application relates to a sonar background noise simulation modeling method and system based on measured data, which comprises the following steps: S1, constructing a sonar background noise simulation calculation model according to different sonar types; S2, acquiring a sound base array spatial sound field and vibration distribution; the sound base array spatial sound field and vibration distribution conditions comprise background noise data received by the sound base array and background noise data measured by sensors around the sound base array; and S3, calculating a transfer function of a simulation model established according to the sound base array spatial sound field and vibration distribution data acquired in the step S2, wherein the transfer function comprises a vibration-sound transfer function and a sound-sound transfer function. The application can realize accurate and comprehensive prediction of sonar background noise, and provides a technical basis for a comprehensive suppression scheme of sonar background noise.

Description

Technical fields:

[0001] This invention belongs to the field of acoustics technology, specifically relating to a method and system for simulating and modeling sonar background noise 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 level of background noise in its operating environment. The background noise of bow sonar mainly consists of acoustic interference generated by structures inside and around the fairing. This interference directly affects the sonar's detection performance, reduces the signal-to-noise ratio of the sonar receiving system, disrupts beamforming, and shortens the detection range while decreasing accuracy. The composition of sonar background noise is relatively complex, generally classified into four categories according to its source: mechanical noise, hydrodynamic noise, propeller noise, and marine environmental noise. Marine environmental noise differs from the other three by more than 10 dB, but this noise component is usually negligible. Therefore, the prediction of sonar background noise mainly refers to the simulation modeling of mechanical noise, hydrodynamic noise, and propeller noise.

[0003] Existing simulation methods for sonar background noise primarily involve establishing separate models for these three types of noise. Mechanical noise simulation methods predict noise by applying mechanical excitation to create an acoustic-structure interaction model, but the mechanical excitation source differs significantly from the actual vibration source. Hydrodynamic noise simulation methods calculate pulsating pressure through flow field simulation to create a sound radiation model, but hydrodynamic noise calculations often require substantial computational resources and effort. Propeller noise prediction mainly relies on fluid-structure interaction models to calculate the radiated sound field; however, propagation noise has multiple transmission paths when reaching the bow fairing, leading to poor calculation accuracy. In other words, existing simulation methods use empirical or singular input conditions when establishing sonar background noise prediction models, only simulating one of the three types of sonar background noise (mechanical, hydrodynamic, or propeller noise). Furthermore, they cannot match actual experimental conditions, resulting in sonar background noise prediction models that deviate significantly from reality and fail to accurately reflect actual sonar background noise levels. 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 sonar background noise based on measured data, establishes the excitation source and sound source under actual working conditions, and simulates and calculates sonar background noise by inputting noise source conditions, so as to achieve accurate and comprehensive prediction of sonar background noise and provide a technical basis for comprehensive suppression schemes of sonar background noise.

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

[0006] S1: Construct simulation calculation models for sonar background noise based on different sonar types;

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

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

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

[0010] S5: Input the noise source and vibration source obtained from the inversion to calculate the background noise field of the sonar.

[0011] This invention uses measured data to infer the noise sources of sonar background noise. Since the measured data is information generated by the superposition of multiple noise sources, the noise source includes all information sources in the sonar background noise, such as mechanical noise, hydrodynamic noise, and propeller 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, thus achieving a comprehensive and accurate prediction of sonar background noise and providing a technical basis for comprehensive sonar background noise suppression schemes.

[0012] As a preferred option, step S1 is performed as follows:

[0013] Step S1.1: Establish a sonar simulation calculation model based on the hull shape. For sonars in different locations, such as bow acoustic array, side array, and towed array, it is only necessary to establish the adjacent related area transmission compartments or structures.

[0014] Step S1.2: Simplify the structure and divide it into discretized meshes according to the mesh requirements;

[0015] Step S1.3: Assign material properties to all panels according to different compartment structures and connection types.

[0016] As a preferred option, step S2 is performed as follows:

[0017] Step S2.1: Four hydrophones are arranged at 90-degree intervals around the circumference of the acoustic array, and three rings 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 top and bottom surfaces of the acoustic array, which are divided into twelve equal parts and at the connection points.

[0018] Step S2.2: Connect all the hydrophones and accelerometers to the acquisition system and collect the signals;

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

[0020] As a preferred option, step S3 is performed as follows.

[0021] Step S3.1: Determine the calculation frequency range of the transfer function based on the operating frequency band of the acoustic array;

[0022] Step S3.2: Establish the load loading position in the simulation calculation model, wherein the force load is established at the center position of the rear bulkhead of the connecting compartment, and the acoustic load is established at the center position of the stern compartment.

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

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

[0025] As a preferred option, step S4 is performed as follows:

[0026] Step S4.1: The vibration and acoustic response data collected by hydrophones and accelerometers arranged at the circumferential position and upper and lower surfaces of the acoustic array are used as the response output of the linear system.

[0027] Step S4.2: Establish the acoustic-vibration coupling equation based on the vibration-acoustic transfer function S1(f), the acoustic-acoustic transfer function S2(f), and the above response output;

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

[0029] As a preferred option, step S5 is performed as follows.

[0030] Step S5.1: Based on the noise source and vibration source obtained, which are the noise source and vibration source under actual working conditions, substitute them into the transfer function of the simulation calculation model, and calculate the background noise under actual working conditions by solving the acoustic-vibration coupling equation.

[0031] Step S5.2: 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, then the sonar background noise simulation modeling method based on the measured data is correct.

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

[0033] The simulation model building module constructs a simulation calculation model based on the structural line diagram.

[0034] The test module collects vibration and sound field data according to the sensor arrangement, and the noise source inversion module inverts the vibration source and noise source based on the vibration-sound transfer function and sound-sound 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] This invention uses transfer functions derived from measured data to invert noise sources and calculate the background noise of a sonar platform. This avoids complex acoustic-structure interaction and fluid-structure interaction solution methods, effectively saving a significant amount of hardware and software computing resources. Furthermore, it calculates the superimposed sound field of multiple sound sources in the platform's background noise within a single simulation model, overcoming the limitation of existing simulation techniques that can only solve for a single type of background noise. This greatly improves the efficiency of sonar background noise modeling and provides a solid technical foundation for subsequent comprehensive sonar background noise suppression schemes. Attached image description:

[0038] Figure 1 This is a flowchart illustrating the method of the present invention.

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

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

[0041] Figure 4 The noise source is inverted in the embodiment of the present invention.

[0042] Figure 5 The results are the calculation results of the sonar background noise in the embodiments of the present invention. Detailed implementation method:

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

[0044] A method for simulating and modeling sonar background noise based on measured data is proposed to achieve comprehensive and accurate prediction of sonar background noise. The method flow of this invention is as follows: Figure 1 As shown. To achieve the aforementioned objective, the technical solution steps of the present invention are as follows:

[0045] 1. Constructing a simulation calculation model for sonar background noise; This embodiment uses a bow sonar as an example for illustration, specifically including the following steps.

[0046] 1.1 A simulation model of the bow sonar is established based on the hull lines, including the fairing acoustic cavity, stern water tanks, air compartments, upper air compartment of the fairing, and acoustic array model, as shown below. Figure 2 As shown;

[0047] 1.2 The structure is simplified and discretized according to the mesh requirements;

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

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

[0050] 2.1 Four hydrophones are arranged at 90-degree intervals around the circumference of the acoustic array, and three rings of hydrophones are arranged in three equal parts along the height of the acoustic array, for a total of 12 hydrophones; a total of 26 accelerometers are arranged at the twelve equal parts of the upper and lower surfaces of the acoustic array and at the connection points.

[0051] 2.2 Connect all hydrophones and accelerometers to the data acquisition system and collect their signals;

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

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

[0054] 3. Calculate the transfer function based on the established simulation model, specifically including the following steps.

[0055] 3.1 Determine the calculation frequency range of the transfer function based on the operating frequency band of the acoustic array;

[0056] 3.2 The load loading position is established in the simulation calculation model. In this embodiment, the force load is established at the center of the rear bulkhead of the connecting compartment, and the acoustic load is established at the center of the stern compartment.

[0057] 3.3 The internal sound field S1(f) of the simulation model is obtained by applying a 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 obtained by applying a unit acoustic wave excitation to the simulation model. According to the linear system theory, S2(f) is the acoustic-to-acoustic transfer function of the simulation model.

[0059] 4. Infer the noise and vibration sources based on the measured data; for example... Figure 3 , 4 As shown, the specific steps include:

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

[0061] 4.2 Based on the vibration-sound transfer function S1(f) and the sound-sound transfer function S2(f) and the above response output, establish the acoustic-vibration coupling equation;

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

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

[0064] 5. Input the noise source and vibration source obtained from the inversion to calculate the sonar background sound field; specifically including the following steps.

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

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

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

[0068] The simulation model building module constructs a simulation calculation model based on the structural line diagram.

[0069] The test module collects vibration and sound field data according to the sensor arrangement, and the noise source inversion module inverts the vibration source and noise source based on the vibration-sound transfer function and sound-sound 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] This invention retrieves the noise source of sonar background noise based on measured data, establishes the excitation source and sound source under actual operating conditions, and calculates the sonar background noise by simulating the input noise source conditions, so as to achieve accurate and comprehensive prediction of sonar background noise and provide a technical basis for comprehensive suppression schemes of sonar background noise.

[0072] The above description only illustrates preferred embodiments of the present invention and should not be construed as limiting the scope of the claims. Any equivalent procedural modifications made using this specification are included within the patent protection scope of this invention.

Claims

1. A method for simulating and modeling sonar background noise based on measured data, characterized in that: Includes the following steps, S1: Construct simulation calculation models for sonar background noise based on different sonar types; S2: Acquire the spatial sound field and vibration distribution of the acoustic array; the spatial sound field and vibration distribution of the acoustic array includes the background noise data received by the acoustic array and the background noise data measured by the sensors around the acoustic array. S3: Calculate the transfer function of the simulation model established based on the spatial sound field and vibration distribution data of the acoustic array obtained in step S2, including the vibration-acoustic transfer function and the sound-acoustic transfer function. S4: Infer the noise source and vibration source based on the measured data; S5: Input the noise source and vibration source obtained from the inversion to calculate the background noise field of the sonar; The specific steps for step S1 are as follows: Step S1.1: Establish a sonar simulation calculation model based on the hull shape, and establish adjacent related regional transmission compartments or structures for sonars at different locations; Step S1.2: Simplify the structure and divide it into discretized meshes according to the mesh requirements; Step S1.3: Assign material properties to all panels according to different compartment structures and connection types; The specific operation of step S2 is as follows: Step S2.1: Four hydrophones are arranged at 90-degree intervals around the circumference of the acoustic array, and three rings 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 top and bottom surfaces of the acoustic array, which are divided into twelve equal parts and at the connection points. Step S2.2: Connect all the hydrophones and accelerometers to the acquisition system and collect the signals; Step S2.3: Simultaneously collect real-time experimental data received by the acoustic array; The specific operation of step S3 is as follows: Step S3.1: Determine the calculation frequency range of the transfer function based on the operating frequency band of the acoustic array; Step S3.2: Establish the load loading position in the simulation calculation model, wherein the force load is established at the center position of the rear bulkhead of the connecting compartment, and the acoustic load is established at the center position of the stern compartment. Step S3.3: The internal sound field S1(f) of the simulation model is calculated by applying a unit force excitation to the simulation model. At this time, S1(f) is the vibration-acoustic transfer function of the simulation model. Step S3.4: The internal sound field S2(f) of the simulation model is calculated by applying unit acoustic wave excitation to the simulation calculation model. At this time, S2(f) is the sound-to-sound transfer function of the simulation model. The specific operation of step S4 is as follows: Step S4.1: The vibration and acoustic response data collected by hydrophones and accelerometers arranged at the circumferential position and upper and lower surfaces of the acoustic array are used as the response output of the linear system. Step S4.2: Establish the acoustic-vibration coupling equation based on the vibration-acoustic transfer function S1(f), the acoustic-acoustic transfer function S2(f), and the above response output; Step S4.3: The excitation source of this linear system is obtained by solving the above acoustic-vibration coupling equation. The excitation source is the vibration source and the noise source. The specific operation of step S5 is as follows: Step S5.1: Based on the obtained noise source and vibration source, substitute the transfer function of the simulation calculation model, and calculate the background noise under actual working conditions by solving the acoustic-vibration coupling equation. Step S5.2: 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, then the sonar background noise simulation modeling method based on the measured data is correct.

2. A system using the sonar background noise simulation modeling method based on measured data as described in claim 1, characterized in that: include, The simulation model building module constructs a simulation calculation model based on the structural line diagram. The test module collects vibration and sound field data according to the sensor arrangement, and the noise source inversion module inverts the vibration source and noise source based on the vibration-sound transfer function and sound-sound 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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