Ship tail abnormal noise source separation method and system

Abstract

The invention provides a ship tail abnormal noise source separation method and system, and the method comprises the steps: employing a ship noise reference benchmark database, combining ship water navigation features, and sequentially collecting noise source correlation features when a ship is in an independent start-stop state, a steady state working condition and an unsteady state working condition of each main and auxiliary equipment; performing preset combined analysis of total-level contrastive analysis, 1 / 3oct frequency band analysis, line spectrum analysis, DEMON spectrogram analysis, frequency multiplication analysis and LOFAR spectrum analysis on the noise source correlation characteristics to obtain a plurality of ship tail abnormal noise source correlation results; and determining a noise comprehensive proportion of a plurality of ship tail abnormal noise source correlation results, and generating a ship tail abnormal noise source separation analysis result. According to the method, the problems of incomplete testing, inaccurate positioning and unclear abnormal reason analysis in the ship tail abnormal noise processing process can be solved, and technical support is provided for formulating an abnormal noise troubleshooting and repairing scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of noise measurement, and particularly to a method and system for separating abnormal noise sources at the ship's stern. Background Art

[0002] Due to the numerous equipment and complex structure at the ship's stern, the treatment of abnormal noise at the stern involves many projects and has a long construction period. At the same time, due to the large number of noise sources at the ship's stern, extensive transmission paths, complex causes of abnormal noise, and phenomena such as multi-factor coupling, it is difficult to separate, locate, and analyze the causes of abnormal noise sources, further leading to difficulties in troubleshooting and repairing abnormal noise on ships. According to incomplete statistics, the solution period for abnormal noise problems at the ship's stern is as short as 1 - 3 months, as long as 6 - 12 months, and some even take several years without being effectively solved.

[0003] In recent years, in order to solve the noise problem at the ship's stern, many tests and analyses have been carried out in related research fields, but the effects are not good, and there are still problems such as incomplete testing, inaccurate positioning, and unclear analysis of abnormal causes. Summary of the Invention

[0004] The present invention provides a method and system for separating abnormal noise sources at the ship's stern to solve the defects of frequent occurrence of abnormal noise phenomena at the ship's stern in the prior art, incomplete testing, inaccurate positioning, and unclear analysis of abnormal causes in the treatment method, and to solve the problems of difficult separation of noise sources and difficult positioning of abnormal causes at the ship's stern.

[0005] In a first aspect, the present invention provides a method for separating abnormal noise sources at the ship's stern, including: Obtaining the multi-dimensional noise test results of the ship, and constructing a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship without abnormal noise in the multi-dimensional noise test results of the ship; Using the ship noise reference benchmark database, and combining with the navigation characteristics of the ship in water, collecting the noise source correlation characteristics in turn when the ship is in the single start-stop state, steady-state condition, and non-steady-state condition of each main and auxiliary equipment; Performing a preset combined analysis of total level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis, and LOFAR spectrum analysis on the noise source correlation characteristics to obtain multiple abnormal noise source correlation results at the ship's stern; Determining the comprehensive noise proportion of the multiple abnormal noise source correlation results at the ship's stern, and generating an analysis result for separating abnormal noise sources at the ship's stern.

[0006] A method for separating abnormal noise sources at the stern of a ship provided by the present invention, before obtaining the multi-dimensional noise test results of the ship and constructing a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship without abnormal noise in the multi-dimensional noise test results of the ship, further includes: Obtain the time sensitivity and conditional dependence of the abnormal noise of the ship, and collect the overall judgment information of the user about the noise; According to different ship types, stern structures and design characteristics, determine the noise sources existing at the stern of the ship and related influencing factors, and obtain the ship design parameters and usage process records; Based on the structural vibration theory, the shafting torsional vibration theory and the excitation principle of propeller noise generation, determine the characteristic differences and the relevance of the differences of each noise source.

[0007] A method for separating abnormal noise sources at the stern of a ship provided by the present invention, obtaining the multi-dimensional noise test results of the ship, including: According to the type of the noise source at the stern of the ship, determine the working condition design, measuring point arrangement and measurement parameters of the ship. The working condition design includes the start-stop of each main and auxiliary equipment separately, the uniform straight-ahead test working condition and the variable speed working condition. The measuring point arrangement includes the measuring point position and the measuring point type. The measurement parameters include vibration acceleration and underwater sound pressure; When each main and auxiliary equipment is started and stopped separately, by separately starting and stopping each main and auxiliary equipment one by one, determine the relevance between each abnormal noise source and each main and auxiliary equipment; Under the uniform straight-ahead test working condition, conduct shafting speed increase and decrease tests on the X, Y, and Z axis speeds of the shafting speed respectively in the X-axis speed range, Y-axis speed range, and Z-axis speed range, and obtain the shafting speed at the lowest speed when the abnormal noise appears, the shafting speed at the highest speed when the abnormal noise appears, and the shafting speed at which the abnormal noise frequently appears; Under the variable speed working condition, conduct shafting parking and gliding tests and propeller acceleration tests respectively; The measuring point positions include the shafting support part, the area near the propeller, the hull structure and the external appendage structure. Test the three-way vibration of the shafting support part to obtain the shafting vibration acceleration, test the three-way vibration of the area near the propeller to obtain the propeller vibration acceleration, test the one-way underwater sound of the area near the propeller to obtain the propeller underwater sound pressure level, test the single vibration of the hull structure to obtain the hull vibration acceleration, test the one-way underwater sound of the external appendage structure to obtain the external appendage underwater sound pressure level, and test the single vibration of the external appendage structure to obtain the external appendage vibration acceleration.

[0008] A method for separating abnormal noise sources at the stern of a ship provided by the present invention, constructing a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship without abnormal noise in the multi-dimensional noise test results of the ship, including: Collect the multi-dimensional noise test results of the ship corresponding to different classification test results of the ship's delivery test period, the ship's usage period, the normal test state of the same type of ship, and the abnormal test state of the same type of ship; The ship noise reference benchmark database is composed of different classification test results.

[0009] According to a method for separating abnormal noise sources at the ship's tail provided by the present invention, using the ship noise reference benchmark database and combining the characteristics of ship navigation in water, successively collect the noise source correlation characteristics when the ship is in the state of starting and stopping each main and auxiliary equipment separately, steady-state working conditions, and non-steady-state working conditions, including: When each main and auxiliary equipment is in the state of starting and stopping separately, if any abnormal noise appears when the equipment is turned on and disappears when it is turned off, and has obvious noise characteristics at the preset points of the equipment, then determine that any abnormal noise is the noise associated with the main and auxiliary equipment; Under steady-state working conditions, compare different measuring points under the same working conditions and the same measuring points under different working conditions respectively to determine the main characteristics, associated parts, and variation rules of the abnormal noise; Under non-steady-state working conditions, determine the correlation between the abnormal noise and the propeller, shafting, and outboard structure. According to a method for separating abnormal noise sources at the ship's tail provided by the present invention, perform a preset combined analysis of the noise source correlation characteristics by using total level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis, and LOFAR spectrum analysis to obtain the analysis results of separating abnormal noise sources at the ship's tail, including: Perform total level comparison analysis on different measuring points under the same working conditions and the same measuring points under different working conditions in steady-state working conditions, and determine the total level abnormal data based on the preset sound pressure level decibel threshold; Perform 1 / 3 octave band analysis on the total level abnormal data to determine the abnormal frequency band; Perform line spectrum analysis on the abnormal frequency band to obtain the main characteristics of the abnormal noise, the abnormal part and the associated part, and the variation rule of the abnormal noise with the ship speed; Based on octave analysis and LOFAR spectrum analysis, analyze the main characteristics of the abnormal noise, the abnormal part and the associated part, and the variation rule of the abnormal noise with the ship speed, and combine with the LOFAR spectrum analysis of the shafting coasting under the non-steady-state working conditions to obtain the correlation result with the propeller shaft system noise; Compare the abnormal frequency band with the structural inherent characteristics of the abnormal part to obtain the correlation result with the structural inherent characteristic noise; Compare the abnormal frequency band with the inherent characteristics of the propeller to obtain the correlation result with the propeller inherent characteristic noise; Perform LOFAR spectrum analysis on the propeller acceleration test under the non-steady-state working conditions to obtain the correlation result with the propeller noise. A method for separating abnormal noise sources at the ship's stern provided by the present invention determines the comprehensive noise proportion associated with the results of multiple abnormal noise sources at the ship's stern, and generates an analysis result for separating abnormal noise sources at the ship's stern, including: Respectively obtain the deviation ratios of the results associated with the noise of the propeller shaft system, the results associated with the structural inherent characteristic noise, the results associated with the propeller inherent characteristic noise, and the results associated with the propeller noise, and calculate to obtain the comprehensive noise proportion; Based on the comprehensive noise proportion, output the analysis result for separating abnormal noise sources at the ship's stern.

[0010] In a second aspect, the present invention also provides a system for separating abnormal noise sources at the ship's stern, including: An acquisition and construction module for obtaining the ship's multi-dimensional noise test results, and constructing a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship's multi-dimensional noise test results when there is no abnormal noise on the ship; A collection module for using the ship noise reference benchmark database, combining the ship's water navigation characteristics, and successively collecting the noise source association characteristics when the ship is in the start-stop state of each main and auxiliary equipment alone, the steady-state working condition, and the non-steady-state working condition; An analysis module for performing a preset combined analysis of the noise source association characteristics by using overall level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis, and LOFAR spectrum analysis to obtain multiple results of abnormal noise source associations at the ship's stern; A separation module for comprehensively generating an analysis result for separating abnormal noise sources at the ship's stern based on the noise analysis results in the uniform straight-ahead navigation condition and the noise analysis results in the variable ship speed condition.

[0011] In a third aspect, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the method for separating abnormal noise sources at the ship's stern as described in any one of the above.

[0012] In a fourth aspect, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it implements the method for separating abnormal noise sources at the ship's stern as described in any one of the above.

[0013] The method and system for separating abnormal noise sources at the ship's tail provided by the present invention, based on the existing ship structure vibration theory, combines the characteristics of the ship in the water environment and the characteristics and generation mechanisms of the ship's tail noise sources, proposes a testing method for effectively separating abnormal noise sources at the ship's tail, and aims at the difficulties in separating abnormal noise, proposes a separation method for effectively separating abnormal noise sources at the ship's tail, which can comprehensively, quickly and effectively provide comprehensive technical support for the investigation and repair of various abnormal noises at the ship's tail. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 is a schematic flow chart of the method for separating abnormal noise sources at the ship's tail provided by the present invention; Figure 2 is a flow chart of the testing method for abnormal noise at the ship's tail provided by the present invention; Figure 3 is a schematic flow chart of the separation principle of abnormal noise at the ship's tail provided by the present invention; Figure 4 is a schematic structural diagram of the system for separating abnormal noise sources at the ship's tail provided by the present invention; Figure 5 is a schematic structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the present invention in conjunction with the drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0017] Aiming at the problems that the current technical means for dealing with the ship's tail noise generally have incomplete testing, inaccurate positioning, and unclear analysis of abnormal causes, the present invention proposes a method that can effectively separate abnormal noise sources at the ship's tail, which can effectively solve the problems of incomplete testing, inaccurate positioning, and unclear analysis of abnormal causes in the process of dealing with abnormal noise at the ship's tail, and provide comprehensive technical support for formulating investigation and repair plans for abnormal noise.

[0018] Figure 1It is a schematic flow diagram of a method for separating abnormal noise sources at the ship's stern provided by an embodiment of the present invention. As Figure 1 shown, it includes: Step 100: Obtain the multi-dimensional noise test results of the ship, and construct a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship without abnormal noise in the ship multi-dimensional noise test results; Step 200: Utilize the ship noise reference benchmark database, combine with the ship's water navigation characteristics, and collect the noise source correlation characteristics in turn when the ship is in the separate start-stop state, steady-state condition, and non-steady-state condition of each main and auxiliary equipment; Step 300: Perform a preset combined analysis of total level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis, and LOFAR spectrum analysis on the noise source correlation characteristics to obtain multiple ship stern abnormal noise source correlation results; Step 400: Determine the comprehensive noise ratio of the multiple ship stern abnormal noise source correlation results, and generate a ship stern abnormal noise source separation analysis result.

[0019] In one embodiment, before step 100, it further includes: Obtain the time sensitivity and conditional dependence of the ship's abnormal noise, and collect the overall judgment information of the user regarding the noise; According to different ship types, stern structures, and design characteristics, determine the noise sources and associated influencing factors existing in the ship's stern, and obtain the ship design parameters and usage process records; Based on the structural vibration theory, shafting torsional vibration theory, and propeller noise generation excitation principle, determine the characteristic differences and difference correlations of each noise source.

[0020] It should be noted that there are many noise sources at the ship's stern and the transmission path is complex. In addition to the direct radiation generated by the abnormal noise source itself, there are also phenomena where a single noise source excites multiple structures to generate abnormal noise and multiple noise sources simultaneously excite a single structure to generate abnormal vibration noise.

[0021] The ship benchmark database is a very large scope and almost includes all information. However, for the abnormal noise at the stern, this benchmark database should be selective and targeted. Therefore, before constructing the database, it should include: (1) The timing, conditions, phenomena, and characteristics of the abnormal noise generation should be fully investigated, studied, and analyzed, especially the feelings and judgments of the user regarding the abnormal noise at the ship's stern need to be carefully listened to and analyzed.

[0022] (2) According to different ship types, stern structures, and design characteristics, judge the possible noise sources and associated influencing factors at the stern. If necessary, relevant ship design parameters and usage process records can be consulted; (3)Based on the structural vibration theory, the shafting torsional vibration theory, and the excitation of propeller noise, etc., determine the characteristics differences and existing correlations of each noise source.

[0023] Specifically, the noise sources at the ship's stern mainly consist of the noise of the propeller shaft system, the vibration noise of the main and auxiliary engines, and the structural vibration noise. Due to different generation mechanisms, there are certain differences in the main characteristics of abnormal noise. Among them, the vibration of the main and auxiliary engines is closely related to the equipment operating state and is generally easy to separate. The structural vibration noise and the noise of the propeller shaft system are closely related to the ship's navigation state, and it is difficult to perceive and judge by the human ear inside the cabin, resulting in problems such as difficult separation and difficult positioning.

[0024] The generation mechanisms of the structural vibration noise and the noise of the propeller shaft system at the ship's stern are as follows: (1)Structural vibration noise According to the structural vibration mode theory, the structural vibration response can be expressed as: (1) Among them, is the angular frequency, is the structural response at on the structure, is the excitation force at on the structure, is from point to the frequency response function of point (2) Among them, , is the th modal shape coefficient, 、 、 are respectively the th modal stiffness, modal mass, and modal damping, is the imaginary unit, is the modal order.

[0025] For the hull structure mainly composed of metal plates, the modal damping is usually used to represent the damping coefficient, and we can get: (3) Among them, .

[0026] From equations (2) and (3), it can be seen that the structural frequency response function It is related to modal stiffness, modal mass and damping. For a given hull structure form, the frequency response function does not change with external excitation. As can be seen from (1), under the condition of a determined frequency response function, the response of the structural system is mainly determined by the system excitation force. When the excitation force changes, the structural response will change accordingly.

[0027] In addition, during the navigation of the ship, the structure is subjected to excitations from fluids, mechanical equipment and the propeller shaft system. Among them, the excitation force of the mechanical equipment is closely related to the power of the equipment when it is turned on, and generally shows a steady-state characteristic; the excitation of the fluid on the hull structure is closely related to the fluid excitation force. According to the relationship formula between the Strouhal number and frequency in fluid mechanics: (4) where, is the vortex shedding frequency on the structure, is the characteristic length, is the fluid velocity, ‌ is the Strouhal number. When the ship's speed changes, the fluid excitation frequency will change accordingly. The vibration response of the propeller shaft system exciting the hull structure has an obvious corresponding relationship with the shafting excitation force, that is, as the excitation force increases with the increase of the ship's speed, the structural vibration response increases; when the shafting excitation force disappears, the vibration response characteristics disappear.

[0028] (2)Propeller shaft system noise According to the theory of torsional vibration of the shafting, the solution of the lateral (y-direction) vibration of the shafting is: (5) where, , , is the wave speed component in the lateral (y-direction) of the shafting, represents stiffness, is the angular frequency component in the lateral (y-direction) of the shafting, , , and respectively represent multi-order coefficients decomposed by represents the x-axis component, represents the time component, is the moment of inertia of the shafting cross-section about the Z-axis, m is the mass per unit length of the shafting, is the time function to be solved in the lateral (y-direction) of the shafting.

[0029] The solution of the vertical (Z-direction) vibration of the shafting is: (6) where, , , is the wave speed component in the transverse direction (z - direction) of the shafting, is the angular frequency component in the transverse direction (z - direction) of the shafting, , , and respectively represent the multi - order coefficients after decomposition, represents the x - axis component, represents the time component, is the moment of inertia of the shafting interface about the Y - axis, m is the mass per unit length of the shaft, is the time function to be solved in the transverse direction (z - direction) of the shafting.

[0030] The solution of the torsional vibration of the shafting rotor is: (7) where, , , , are the parameters determined by the boundary conditions of the shafting, represents the angular frequency component in the time dimension, represents the wave speed component in the time dimension.

[0031] It can be seen from the above equations (5), (6), and (7) that the shafting vibration is a wide - band continuous spectrum. Under certain conditions, it will exhibit harmonic characteristics.

[0032] According to the mechanism of propeller noise generation, the average sound power spectrum of propeller noise can be expressed as: (8) (9) (10) where, is the time period, is the angular frequency, is the imaginary unit, is the pulse signal function generated by cavitation collapse, satisfying the condition: , and when time, ; is the cavitation noise amplitude factor generated by the propeller, is the pulse effective width, is the cavitation pulse function after Fourier transform, is a random quantity with a mean of 0, is the average sound power spectrum of the propeller noise, is the system's linear spectral response function, is the system's non - linear spectral response function, is the mathematical expectation function, is the natural constant.

[0033] As can be seen from Equation (6), the average power spectrum of the propeller cavitation noise consists of two parts: a continuous spectrum and a line spectrum, which are respectively (11) The line - spectrum frequencies only appear at and are manifested as harmonics of the shaft frequency, is the time period.

[0034] When the propeller operates in a relatively uniform wake, a relatively stable cavitation pattern will form. During one rotation, there is also a certain axial non - uniformity, but the general characteristics are not obvious and no cavitation, "singing" or "weak singing" will occur. During use, when the propeller has cracks, fissures, blade contamination or improper repair resulting in a change in the propeller state, it will exacerbate the axial non - uniformity of the wake velocity, increasing the excitation force on the propeller. When the excitation - force frequency couples with the natural frequency of the blade structure to cause resonance, "singing" or "weak singing" appears.

[0035] In summary, the following conclusions can be obtained: (1) The equipment inside the cabin excites the hull structure, and the structural response characteristics are determined by the stiffness, damping, etc. of the hull structure itself. The response amplitude has an obvious corresponding relationship with the equipment excitation force; (2) When the excitation force generated by the propeller shaft system excites the hull structure, the structural response characteristics are determined by the stiffness, damping, etc. of the hull structure itself. The structural response amplitude changes with the rotational speed. When the shaft - system excitation force disappears, the vibration response disappears; (3) When the external flow outside the hull excites the hull structure or cavity, the structural response characteristics are determined by the stiffness, damping, etc. of the hull structure itself. The structural response amplitude has an obvious corresponding relationship with the ship's speed. When the speed decreases, the response - amplitude characteristics decrease or disappear; (4) The shaft - system vibration is generally a continuous spectrum and has harmonic characteristics, while the propeller cavitation noise shows characteristics of continuous spectrum + discrete spectrum. The discrete spectrum is manifested as harmonics of the propeller blade frequency and appears at integer multiples of the shaft frequency; The frequencies of the propeller "singing" or "weak singing" are strongly correlated with the inherent characteristics of the propeller blades. When the ship's speed changes, the corresponding frequencies also change.

[0036] In one embodiment, step 100 includes: Determine the working conditions design, measuring point arrangement, and measurement parameters of the ship according to the types of noise sources at the ship's stern. The working conditions design includes the individual start-stop of each main and auxiliary equipment, the uniform straight-ahead test condition, and the variable speed condition. The measuring point arrangement includes the measuring point location and the measuring point type. The measurement parameters include vibration acceleration and underwater sound pressure; When each main and auxiliary equipment is individually started and stopped, determine the correlation between each abnormal noise source and each main and auxiliary equipment by individually starting and stopping each main and auxiliary equipment one by one; Under the uniform straight-ahead test condition, conduct shafting speed increase and decrease tests on the X, Y, and Z axis speeds of the shafting speed in the X-axis speed range, Y-axis speed range, and Z-axis speed range respectively, and obtain the shafting speed at the lowest speed when the abnormal noise appears, the shafting speed at the highest speed when the abnormal noise appears, and the shafting speed at which the abnormal noise frequently appears; Under the variable speed condition, conduct shafting parking coasting tests and propeller acceleration tests respectively; The measuring point locations include the shafting support parts, the area near the propeller, the hull structure, and the external appendage structure. Test the three-way vibration of the shafting support parts to obtain the shafting vibration acceleration, test the three-way vibration of the area near the propeller to obtain the propeller vibration acceleration, test the one-way underwater sound of the area near the propeller to obtain the propeller underwater sound pressure level, test the single vibration of the hull structure to obtain the hull vibration acceleration, test the one-way underwater sound of the external appendage structure to obtain the external appendage underwater sound pressure level, and test the single vibration of the external appendage structure to obtain the external appendage vibration acceleration.

[0037] Specifically, due to the large number of abnormal noise sources in the ship's parts, the wide transmission paths, and the complex causes of abnormal noise, in the existing abnormal noise treatment process, generally only the working conditions when the abnormal noise appears and the vibration of the shafting-related parts are measured, resulting in inaccurate analysis or even failure to find the abnormal noise source due to incomplete measurement.

[0038] The embodiments of the present invention formulate a method for separating abnormal noise at the stern in a targeted manner according to the different characteristics of the abnormal noise at the ship's stern, following the following principles: First, the measuring point arrangement should cover the main noise sources at the ship's stern and their transmission paths, including the feet, bases of the main equipment, pipeline support parts, main appendages and structures, shafting support parts, areas near the propeller, etc. Through the above measuring points, lock in the areas and scopes where the abnormal noise appears and has an impact. Among them, considering the complexity of the vibration noise formation of the propeller shaft system, generally three-way measuring points are arranged for the propeller shaft system, namely the X, Y, and Z directions.

[0039] Second, the operating condition design should not only cover all operating conditions where abnormal noise occurs, but also be able to accurately determine the changes in the characteristics of abnormal noise. Generally, it not only includes the main navigation operating conditions of the ship, but also needs to moderately increase other voyages with similar speeds for the operating conditions where abnormal noise appears frequently. Through the above operating condition design, the range where abnormal noise appears, its abnormal characteristics and their changing rules are locked in.

[0040] Third, different combinations of operating conditions need to be carried out to ensure that different noise sources can be distinguished. According to the characteristics of the main noise sources at the stern, generally, there are three major categories of operating conditions: 1. The operating condition of starting and stopping the main and auxiliary equipment separately. By starting and stopping the main and auxiliary equipment at the stern one by one, the correlation between the abnormal noise source and the main and auxiliary equipment is determined; 2. The operating condition of stopping and gliding. Generally, multiple speeds can be set for stopping and gliding. When a certain characteristic drops sharply or disappears with the decrease of the speed during the stopping and gliding process, it indicates that this phenomenon has an obvious correlation with the propeller shaft system. Through the operating condition of stopping and gliding, the correlation between the abnormal noise and the propeller shaft system and the possibility of the abnormal noise and the flow-induced structure and cavity can be determined. 3. The operating condition of the propeller acceleration test. During the sharp acceleration of the propeller, the uniformity of the flow field around the propeller will be changed sharply, inducing abnormal noise phenomena, and then the correlation between the abnormal noise and the propeller can be determined. In addition, according to the phenomena and characteristics of abnormal noise generation of each ship, other operating conditions can be moderately increased, such as steering, releasing and recovering the outboard device, etc.; for more complex abnormal noise at the stern, if necessary, near-field radiation noise measurement, etc. also need to be added for separation and verification.

[0041] The specific content and requirements are as Figure 2 shown: First, when starting and stopping each main and auxiliary equipment separately, by starting and closing each main and auxiliary equipment separately one by one, the correlation between each abnormal noise source and each main and auxiliary equipment is determined.

[0042] Next, tests are carried out under different operating condition designs. N, M, and L are the increase and decrease values of the rotational speeds in the X, Y, and Z directions of the ship's shafting rotational speed respectively, so as to form corresponding rotational speed intervals [X - N, X + N], [Y - M, Y + M], and [Z - L, Z + L] in the three directions respectively. The unit of the shafting rotational speed is r / min, that is, the rotational speed per minute. N, M, and L can be designed according to different ship types. For ships with lower rotational speeds, values such as 5 or 10, 20, etc. can be taken. During the measurement process, the number of voyages can be moderately increased according to the occurrence law of abnormal noise.

[0043] Under the condition of uniform straight-line navigation, shafting rotational speed increase and decrease tests are carried out in the rotational speed intervals of the X-axis, Y-axis, and Z-axis to obtain the shafting rotational speed at the lowest speed where abnormal noise appears, the shafting rotational speed at the highest speed where abnormal noise appears, and the shafting rotational speed at the speed where abnormal noise appears frequently, as Figure 2The minimum shaft speed X r / min at which abnormal noise appears in the X direction shown, the shaft speed Y r / min at which abnormal noise frequently appears, and the maximum shaft speed Z r / min at which abnormal noise appears.

[0044] Under variable ship speed conditions, shafting coasting tests and propeller acceleration tests are respectively carried out. Here, shafting coasting generally refers to the state where, during the process of a ship adjusting its speed, after actively shutting down the main engine power, the shafting and the propeller stop rotating, and the ship continues to coast by inertia until the ship speed gradually decays to a standstill.

[0045] Furthermore, by arranging different measuring point positions, measurement parameters of different measuring point types are obtained. The three-way vibration of the shafting support part is tested to obtain the shafting vibration acceleration, the three-way vibration of the area near the propeller is tested to obtain the propeller vibration acceleration, the single-direction underwater sound of the area near the propeller is tested to obtain the propeller underwater sound pressure level, the single-item vibration of the hull structure is tested to obtain the hull vibration acceleration, the single-direction underwater sound of the outboard appendage structure is tested to obtain the outboard appendage underwater sound pressure level, and the single-direction vibration of the outboard appendage structure is tested to obtain the outboard appendage vibration acceleration.

[0046] In one embodiment, according to the acoustic characteristics of the ship corresponding to the ship's multi-dimensional noise test results when there is no abnormal noise, a ship noise reference benchmark database is constructed, including: Collect different classification test results of the ship's multi-dimensional noise test results corresponding to the ship's delivery test period, the ship's usage period, the normal test state of the same type of ship, and the abnormal test state of the same type of ship; The different classification test results constitute the ship noise reference benchmark database.

[0047] It can be understood that according to Figure 2 the process shown in Figure 3 a ship can be comprehensively tested to obtain a complete set of test results. In order to more comprehensively analyze the ship's tail noise, more comprehensive test results need to be obtained from multiple dimensions. Therefore, as

[0048] shown in Figure 3 this embodiment of the present invention considers the test results of the ship at different times, including the test results of this ship at the time of delivery, the test results of this ship during use, and also analogizes the normal test results of the same type of ship and the abnormal test results of the same type of ship to form a complete ship noise reference benchmark database. Taking this database as the input set, subsequent analysis work is carried out.

[0049] In the existing process of dealing with abnormal noise at the tail, methods such as overall level, 1 / 3 octave band level and line spectrum analysis are generally used. By using the above methods, it is basically possible to determine whether there is abnormal noise at the ship's tail, but it is difficult to determine the location and cause of the abnormal noise source. Based on the overall level analysis, 1 / 3 octave band level analysis and line spectrum analysis, the embodiments of the present invention use the Low-Frequency Array (LOFAR) spectrum analysis method, the Detection of Envelope Modulation on Noise (DEMON) spectrogram analysis method and the octave analysis method to analyze the signals under special working conditions and special parts, so as to extract the characteristics of abnormal noise. Among them, the overall level analysis is a comprehensive measurement of the overall energy of the signal, without distinguishing specific frequency bands, and directly calculating the total sound pressure level or vibration energy value in the full frequency domain; the 1 / 3 oct (one-third octave) band analysis divides the frequency range into finer frequency bands according to geometric geometric progression, and the center frequency of each frequency band satisfies the formula f high / f low = 21 / 3 f high / f low = 21 / 3, that is, the upper limit frequency of adjacent frequency bands is about 1.26 times that of the lower limit; the line spectrum analysis converts the time-domain signal into a frequency-domain signal through the fast Fourier transform, and identifies the discrete line spectrum components in the spectrum, such as harmonics generated by periodic vibration or electromagnetic interference.

[0050] Specifically, the principles of the LOFAR spectrum analysis method and the DEMON spectrogram analysis method are as follows: (1) LOFAR spectrum analysis method: Divide the sampling sequence of the original signal into several continuous segments, each segment has sampling points, is any sampling point, and the variable is obtained; then, perform normalization and centering processing on each segment of the signal sampling sample to obtain the variable ; finally, perform a short-time Fourier transform on the variable

[0051] (12) (13) The LOFAR spectrum analysis method forms a three-dimensional time-frequency diagram of signal expression by performing a short-time Fourier transform on the sampled data, and can perform joint domain analysis on the signal from both time and frequency perspectives, and is suitable for signals with non-stationary characteristics.

[0052] (2) DEMON spectrogram analysis method: According to the signal modulation principle, assuming that the received signal is modeled as a periodic locally stationary process, it can be expressed as: (14) Among them, is a wideband stationary white Gaussian random process, is a modulation function, and the modulation function can be obtained by using the square demodulation method . By performing a fast Fourier transform on the obtained demodulated signal, the DEMON spectrogram of the demodulated signal can be obtained.

[0053] In the noise of the ship's stern, there is obvious amplitude modulation in the propeller noise, and the modulation frequency is equal to the shaft frequency or the propeller blade frequency. The propeller noise can be separated by using the DEMON spectrogram analysis method.

[0054] According to the different characteristics of the ship's stern noise sources, different working conditions, measuring points, and parameters, the abnormal noise sources at the ship's stern can be separated. Generally, the following principles are followed in the analysis process: First, the data analysis should be carried out on the basis of basically mastering the acoustic characteristics of the ship without abnormal noise. Mastering the acoustic characteristics of the ship without abnormal noise includes referring to the test results of each system and equipment during ship delivery, the test results collected during use, and the test results of other ships of the same type. When it comes to the inherent characteristics of the propeller and the external structure, it is also necessary to obtain the inherent characteristic parameters such as the natural frequency of the propeller and the natural frequency of the structure.

[0055] Second, the data analysis is generally carried out in the order from simple to complex and from steady-state to non-steady-state working conditions: 1. First, conduct data analysis when the main and auxiliary equipment is turned on and off one by one. If an abnormal noise appears when the equipment is turned on and disappears when it is turned off, and is obvious at the parts such as the feet, bases, and pipelines of the equipment, it indicates that there is an obvious correlation between the equipment and the abnormal noise. Based on this, the correlation between the main and auxiliary equipment can be initially determined; 2. Then, carry out data analysis under the steady straight-ahead working condition, including comparing different measuring points under the same working condition and comparing the same measuring point under different working conditions, to determine the main characteristics, related parts, and change rules of the abnormal noise; 3. Finally, carry out data analysis under non-steady-state working conditions to determine the correlation between the abnormal noise and the propeller, shafting, and external structure.

[0056] Third, the data analysis generally follows the principle from rough to fine and from the overall level to the line spectrum: 1. First, conduct an overall level comparison analysis of each measuring point under the steady-state working condition. Generally, 3 dB is used as the reference benchmark, that is, if it exceeds the normal acoustic level by more than 3 dB, it is considered that there may be abnormal noise; 2. Conduct 1 / 3 oct analysis on the data with abnormal overall level to analyze whether there are obvious abnormalities in each frequency band and determine the abnormal frequency band; 3. Conduct line spectrum analysis for each working condition on the abnormal frequency band, and carry out LOFAR analysis, DEMON analysis, and comparison analysis with the inherent characteristics of the propeller and the inherent characteristics of the structure under non-steady-state working conditions according to the analysis results, and analyze and obtain the detailed characteristics and generation mechanism of the abnormal noise.

[0057] Correspondingly, as shown in Figure 3The analysis process shown is as follows: I. Steady-state operating conditions For the same operating conditions with different measuring points and the same measuring points under different operating conditions in the steady-state operating conditions, a total level comparison analysis is carried out, and the total level abnormal data is determined based on a preset sound pressure level decibel threshold (usually 3 dB); Perform a 1 / 3 octave band analysis on the total level abnormal data to determine the abnormal frequency band; Perform a line spectrum analysis on the abnormal frequency band to obtain the main characteristics of the abnormal noise, the abnormal part and the associated part, and the variation law of the abnormal noise with the ship speed; Based on the octave analysis and the LOFAR spectrum analysis, analyze the main characteristics of the abnormal noise, the abnormal part and the associated part, and the variation law of the abnormal noise with the ship speed. Combine with the LOFAR spectrum analysis of the shafting stop and coasting under non-steady-state operating conditions to obtain the correlation result with the propeller shaft system noise; Compare the abnormal frequency band with the structural inherent characteristics of the abnormal part to obtain the correlation result with the structural inherent characteristic noise; Compare the abnormal frequency band with the propeller inherent characteristics to obtain the correlation result with the propeller inherent characteristic noise.

[0058] II. Non-steady-state operating conditions Perform a LOFAR spectrum analysis on the propeller acceleration test under non-steady-state operating conditions to obtain the correlation result with the propeller noise.

[0059] Finally, comprehensively combine the noise analysis results of the above steady-state operating conditions and non-steady-state operating conditions. Usually, the bias ratios of the correlation results with the propeller shaft system noise, the correlation results with the structural inherent characteristic noise, the correlation results with the propeller inherent characteristic noise, and the correlation results with the propeller noise are obtained respectively. Verify the relationship with the structural inherent characteristics, clarify the relationship with the propeller shaft system, determine the relationship with the propeller, and verify the relationship with the propeller inherent characteristics respectively, and calculate the comprehensive noise ratio. According to this comprehensive noise ratio, it is possible to clearly locate which specific types of noise have a higher proportion, that is, clarify the main types and causes of the abnormal noise, so as to deal with the relevant types of noise targeted.

[0060] It can be understood that the abnormal noise phenomenon at the tail is mostly induced by the coupling of multiple factors. Finding one of the factors and dealing with it can temporarily relieve the abnormal noise problem, but it cannot completely eradicate it. Therefore, during the process of dealing with the abnormal noise, special attention should be paid to the comprehensiveness and integrity of the analysis, and on this basis, deeply analyze the causes and mechanisms of each abnormal noise, and then solve it thoroughly to prevent phenomena such as scratching the surface, overgeneralizing, and "blind men feeling an elephant".

[0061] The ship tail abnormal noise source separation system provided by the present invention will be described below. The ship tail abnormal noise source separation system described below can be correspondingly referred to the ship tail abnormal noise source separation method described above.

[0062] Figure 4 is a schematic structural diagram of the ship tail abnormal noise source separation system provided by an embodiment of the present invention. As Figure 4 shown, it includes: an acquisition and construction module 41, a collection module 42, an analysis module 43, and a separation module 44, wherein: The acquisition and construction module 41 is used to obtain the ship multi-dimensional noise test results, and construct a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship without abnormal noise in the ship multi-dimensional noise test results; the collection module 42 is used to utilize the ship noise reference benchmark database, combined with the ship water body navigation characteristics, to collect the noise source correlation characteristics in turn when the ship is in the separate start-stop state, steady-state working condition, and non-steady-state working condition of each main and auxiliary equipment; the analysis module 43 is used to perform a preset combined analysis of the total level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis, and LOFAR spectrum analysis on the noise source correlation characteristics to obtain multiple ship tail abnormal noise source correlation results; the separation module 44 is used to synthesize the uniform straight-line navigation condition noise analysis result and the variable ship speed condition noise analysis result to generate a ship tail abnormal noise source separation analysis result.

[0063] Figure 5 illustrates a schematic structural diagram of an electronic device. As Figure 5As shown, the electronic device may include: a processor 510, a communications interface 520, a memory 530, and a communication bus 540. Among them, the processor 510, the communications interface 520, and the memory 530 complete communication with each other through the communication bus 540. The processor 510 may call the logical instructions in the memory 530 to execute the method for separating abnormal noise sources at the ship's stern. The method includes: obtaining the ship's multi-dimensional noise test results, constructing a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship's multi-dimensional noise test results when there is no abnormal noise on the ship; using the ship noise reference benchmark database and combining the ship's water navigation characteristics, successively collecting noise source correlation characteristics when the ship is in the separate start-stop state, steady-state working condition, and non-steady-state working condition of each main and auxiliary equipment; performing a preset combined analysis of total level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis, and LOFAR spectrum analysis on the noise source correlation characteristics to obtain multiple ship stern abnormal noise source correlation results; determining the comprehensive noise proportion of the multiple ship stern abnormal noise source correlation results to generate a ship stern abnormal noise source separation analysis result.

[0064] In addition, when the logical instructions in the above-mentioned memory 530 are implemented in the form of software function units and sold or used as an independent product, they may be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, may be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0065] On the other hand, the present invention also provides a non-transitory computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, it realizes the method for separating abnormal noise sources at the ship's tail provided by the above-mentioned various methods. The method includes: obtaining the multi-dimensional noise test results of the ship, and constructing a ship noise reference benchmark database according to the acoustic characteristics corresponding to the ship without abnormal noise in the multi-dimensional noise test results of the ship; using the ship noise reference benchmark database, combining the navigation characteristics of the ship in water, and successively collecting the noise source correlation characteristics when the ship is in the separate start-stop state, steady-state working condition and non-steady-state working condition of each main and auxiliary equipment; performing a preset combined analysis of total-level comparison analysis, 1 / 3 octave band analysis, line spectrum analysis, DEMON spectrogram analysis, octave analysis and LOFAR spectrum analysis on the noise source correlation characteristics to obtain multiple abnormal noise source correlation results at the ship's tail; determining the comprehensive noise proportion of the multiple abnormal noise source correlation results at the ship's tail, and generating an analysis result for separating abnormal noise sources at the ship's tail. The device embodiments described above are merely illustrative. The units described as separation components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art can understand and implement it without creative work.

[0066] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the essence of the above technical solution, or the part that contributes to the prior art, can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disc, etc., and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for separating abnormal noise sources at the stern of a ship, characterized in that: include: Acquire a ship multi-dimensional noise test result, and construct a ship noise reference database according to the ship multi-dimensional noise test result corresponding to the acoustic characteristics of the ship when there is no abnormal noise; By using the ship noise reference database and combining the navigation characteristics of the ship in water, noise source correlation characteristics are collected in sequence when the ship is in the start-stop state of each main and auxiliary equipment, steady-state working condition and non-steady-state working condition; The noise source correlation characteristics are analyzed by a preset combination of total level comparison analysis, 1 / 3 oct band analysis, line spectrum analysis, DEMON spectrum analysis, octave analysis and LOFAR spectrum analysis to obtain the correlation results of multiple abnormal noise sources at the stern of the ship; Determine the comprehensive noise proportion of the correlation results of the multiple abnormal noise sources at the stern of the ship, and generate the separation analysis results of the abnormal noise sources at the stern of the ship.

2. The method for separating abnormal noise sources at the stern of a ship according to claim 1, characterized in that: Acquiring a ship multi-dimensional noise test result, and before constructing a ship noise reference database according to the ship multi-dimensional noise test result corresponding to the acoustic characteristics of the ship without abnormal noise, the method further includes: Obtain the time sensitivity and condition dependence of abnormal ship noise, and collect users' overall judgment information on noise; According to different ship types, stern structures and design features, determine the noise sources and related influencing factors at the stern of the ship, and obtain the ship design parameters and usage process records; Based on the structural vibration theory, shafting torsional vibration theory and propeller noise generation excitation principle, the characteristic differences and correlations of various noise sources are determined.

3. The method for separating abnormal noise sources at the stern of a ship according to claim 2, characterized in that: Obtain multi-dimensional ship noise test results, including: Determine the ship's operating condition design, measurement point layout and measurement parameters according to the type of the ship's stern noise source, the operating condition design includes the independent start and stop of each main and auxiliary equipment, the uniform speed straight sailing test condition and the variable speed condition, the measurement point layout includes the measurement point position and the measurement point type, and the measurement parameters include vibration acceleration and underwater sound pressure; When each main and auxiliary equipment is started and stopped separately, the correlation between each abnormal noise source and each main and auxiliary equipment is determined by turning on and off each main and auxiliary equipment separately one by one; Under the uniform speed straight flight test condition, the shaft system speed X, Y, and Z three-axis speeds of the shaft system speed are respectively tested for shaft system speed increase and decrease in the X-axis speed range, the Y-axis speed range, and the Z-axis speed range to obtain the shaft system speed at the lowest speed at which abnormal noise occurs, the shaft system speed at the highest speed at which abnormal noise occurs, and the shaft system speed at which abnormal noise occurs frequently; Under the variable speed condition, a shaft system parking taxiing test and a propeller acceleration test are respectively performed; The measuring point positions include a shafting support part, an area near the propeller, a hull structure and an outboard appendage structure. The shafting support part is tested for three-way vibration to obtain shafting vibration acceleration, the area near the propeller is tested for three-way vibration to obtain propeller vibration acceleration, the area near the propeller is tested for unidirectional water sound to obtain propeller water sound pressure level, the hull structure is tested for single vibration to obtain hull vibration acceleration, the outboard appendage structure is tested for unidirectional water sound to obtain the outboard appendage water sound pressure level, and the outboard appendage structure is tested for unidirectional vibration to obtain the outboard appendage vibration acceleration.

4. The method for separating abnormal noise sources at the stern of a ship according to claim 3, characterized in that: According to the acoustic characteristics of the ship when there is no abnormal noise corresponding to the multi-dimensional noise test results of the ship, a ship noise reference database is constructed, including: Collect the ship multi-dimensional noise test results corresponding to different classification test results of the ship delivery test period, the ship use period, the normal test state of the same type of ship and the abnormal test state of the same type of ship; The ship noise reference database is composed of different classification test results.

5. The method for separating abnormal noise sources at the stern of a ship according to claim 1, characterized in that: By using the ship noise reference database and combining the navigation characteristics of the ship in the water, the noise source correlation characteristics are collected in sequence when the ship is in the start-stop state of each main and auxiliary equipment, steady state condition and non-steady state condition, including: When each main and auxiliary equipment is started and stopped separately, if any abnormal noise appears when the equipment is turned on and disappears when it is turned off, and has obvious noise characteristics at the preset points of the equipment, then any abnormal noise is determined to be the noise associated with the main and auxiliary equipment; Under steady-state conditions, comparisons were made between different measuring points under the same conditions and between the same measuring points under different conditions to determine the main characteristics, associated locations and changing patterns of abnormal noise. Under non-steady-state conditions, the correlation between abnormal noise and propeller, shafting and outboard structure is determined.

6. The method for separating abnormal noise sources at the stern of a ship according to claim 5, characterized in that: The noise source correlation characteristics are analyzed by a preset combination of total level comparison analysis, 1 / 3 oct band analysis, line spectrum analysis, DEMON spectrum analysis, octave analysis and LOFAR spectrum analysis to obtain the abnormal noise source separation analysis results at the stern of the ship, including: Perform overall level comparison analysis on different measuring points under the same working condition and the same measuring point under different working conditions under steady-state conditions, and determine overall level abnormal data based on preset sound pressure level decibel thresholds; Performing 1 / 3oct frequency band analysis on the total level abnormal data to determine the abnormal frequency band; Perform line spectrum analysis on the abnormal frequency band to obtain the main characteristics of the abnormal noise, the abnormal location and related locations, and the law of abnormal noise changing with the speed; Based on frequency doubling analysis and LOFAR spectrum analysis, the main characteristics of abnormal noise, abnormal parts and related parts, and the law of abnormal noise changing with speed are analyzed. Combined with LOFAR spectrum analysis of the shaft system parking and taxiing under the non-steady-state working condition, the correlation result with the propeller shaft system noise is obtained; Comparing the abnormal frequency band with the inherent characteristics of the structure of the abnormal part to obtain a noise correlation result with the inherent characteristics of the structure; Comparing the abnormal frequency band with the inherent characteristics of the propeller to obtain a correlation result with the inherent characteristic noise of the propeller; The LOFAR spectrum analysis is performed on the propeller acceleration test under the non-steady-state condition to obtain the results associated with the propeller noise.

7. The method for separating abnormal noise sources at the stern of a ship according to claim 6, characterized in that: Determine the comprehensive noise proportion of the multiple ship stern abnormal noise source association results, and generate the ship stern abnormal noise source separation analysis results, including: Respectively obtain the result of correlation with the propeller shaft system noise, the result of correlation with the inherent characteristic noise of the structure, the result of correlation with the inherent characteristic noise of the propeller, and the bias ratio of the result of correlation with the propeller noise, and calculate the comprehensive noise proportion; Based on the comprehensive noise proportion, the abnormal noise source separation analysis result of the stern of the ship is output.

8. A system for separating abnormal noise sources at the stern of a ship, characterized in that: include: An acquisition and construction module is used to obtain a ship multi-dimensional noise test result, and to construct a ship noise reference database according to the ship multi-dimensional noise test result corresponding to the acoustic characteristics of the ship when there is no abnormal noise; A collection module is used to collect noise source correlation characteristics in sequence when the ship is in a separate start-stop state of each main and auxiliary equipment, a steady-state operating condition, and a non-steady-state operating condition by using the ship noise reference database and combining the ship's water navigation characteristics; An analysis module is used to analyze the noise source correlation characteristics by using a preset combination of total level comparison analysis, 1 / 3 octet frequency band analysis, line spectrum analysis, DEMON spectrum analysis, octave analysis and LOFAR spectrum analysis to obtain correlation results of multiple abnormal noise sources at the stern of the ship; The separation module is used to integrate the noise analysis results of the uniform speed straight sailing condition and the noise analysis results of the variable speed condition to generate a separation analysis result of abnormal noise sources at the stern of the ship.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for separating abnormal noise sources at the stern of a ship as described in any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for separating abnormal noise sources at the stern of a ship as described in any one of claims 1 to 7 is implemented.

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