Vibration spectrum modulation control method based on objective function

Abstract

The invention relates to a vibration spectrum modulation control method based on an objective function, and the method comprises the following steps: S1, constructing the objective function of the vibration radiation noise information of a full-scale model; s2, constructing a signal source function based on the objective function model; s3, controlling the output of a vibration exciter after the output of the signal source passes through a power amplifier; s4, exciting the local hull model by a plurality of vibration exciters, and monitoring a model radiation sound field by a hydrophone; and S5, comparing the spectrum characteristics of the sound field signals monitored by the hydrophone with the target function. The local model is adopted to replace a full-scale model, the local model is used, the problem of site limitation and cost limitation are solved, and meanwhile the test effect of the local model and the test effect of the full-scale model can be closer.

Description

Technical field:

[0001] The invention belongs to the technical field of acoustics, and in particular relates to a vibration spectrum modulation control method based on an objective function. Background technology:

[0002] Vibration test is a necessary part of the performance test of hydroacoustic equipment. The vibration test of hydrophone module can be carried out in the environmental laboratory. At present, in the vibration test of acoustic array, one is to use local scale array model to reduce the size of test platform by reducing the number of tests; the other is to reduce the test platform requirements by using small-scale hydrophone modules. However, none of the above methods can realize the full-scale acoustic array test, and the test platform is inconsistent with the actual acoustic array installation environment, and the acoustic vibration environment is also quite different from the actual one. Because the vibration test of hydrophone array or acoustic array requires a large-scale platform of structure. In the structural vibration engineering test of large model, due to site limitations or cost considerations, when the full-scale model cannot be realized, the scale ratio model is often considered for testing. The scale ratio model is to test by reducing the size of the research object. The scale ratio model needs to comply with the likelihood criterion and use dimensional analysis to ensure the accuracy of the scale ratio test. However, the scale ratio model cannot fully reflect the real effect of the actual scale model. Summary of the invention:

[0003] The technical problem to be solved by the present invention is to provide a vibration spectrum control method based on an objective function, a structural vibration control method that replaces a full-scale model test with a local model test, and controls the vibration test of the local model based on the objective function to solve the problem that the scaled model cannot replace the full-scale model test.

[0004] The technical solution of the present invention is to provide a structural vibration control method that replaces the full-scale model test with a local model test, and controls the vibration test of the local model based on the objective function to solve the problem that the scaled model cannot replace the full-scale model test. The method realizes the vibration radiation noise modeling of the full-scale model by controlling the output of multiple exciters, and specifically includes the following steps:

[0005] S1. Construct an objective function to obtain the vibration radiation noise information of the full-scale model;

[0006] S2, constructing a signal source function based on the target function model;

[0007] S3, the signal source output controls the output of the exciter after passing through the power amplifier;

[0008] S4, multiple vibrators excite the local hull model, and hydrophones monitor the radiated sound field of the model;

[0009] S5, comparing the frequency spectrum characteristics of the sound field signal monitored by the hydrophone with the target function;

[0010] S6. If the objective function is not met, the control signal source is output until the monitoring hydrophone signal spectrum is consistent with the objective function;

[0011] S7. Adjust the output size of the signal source to simulate the vibration radiation noise information of the full-scale model under different levels of conditions.

[0012] When some models cannot be scaled down, the present invention uses a local model to replace the full-scale model. The use of the local model not only solves the site limitation and cost limitation problems, but also makes the test results of the local model and the full-scale model closer, realizes the overall acoustic array vibration simulation test, and achieves a balance between the two major contradictions of site limitation and cost constraint.

[0013] Preferably, the objective function for obtaining the vibration radiation noise information of the full-scale model constructed in step S1 is a characteristic spectrum: it has the characteristics of a white spectrum in the frequency band of 200Hz to 800Hz; an attenuation of about 20dB per octave in the range of 1000Hz to 2000Hz; and a vibro-acoustic response spectrum with an attenuation of about 15dB per octave above 4000Hz.

[0014] Preferably, in steps S3-S4, the output of the signal source controls the output of the vibrator after passing through a power amplifier; this is done by using a vibro-acoustic system to generate 6 signals, which are amplified by 6 power amplifiers and used as inputs to the vibrator; the output of the vibrator drives the 6 vibrators installed in the local model to work, thereby stimulating the platform to generate structural vibrations.

[0015] Preferably, the bandwidth range of the generated 6-channel signals is 1000 Hz-8400 Hz.

[0016] Preferably, comparing the frequency spectrum characteristics of the sound field signal monitored by the hydrophone with the objective function in step S5 means that a suspended hydrophone 15 cm away from the local model surface is connected to a signal collector, a dynamic analysis bandwidth of 6400 Hz and a spectrum width of about 1 Hz are set, and the radiated noise spectrum is recorded. The signal collector performs multiple signal collection, analysis, and averaging until the vibration noise response received by the hydrophone is basically smooth and stable; and the local model vibration noise response spectrum and the expected objective function noise response spectrum are analyzed, and comparative operation analysis is performed to obtain a modified platform excitation noise spectrum.

[0017] Preferably, in step S6, different outputs of the signal source function are controlled according to the monitoring signal spectrum of the hydrophone, the signal source function corresponds to the input signals of different exciters, the input signals of exciters at different positions are switched, and the output excitations of exciters at different positions are controlled at the same time so that the radiated sound field of the local model meets the objective function of the vibration radiation noise information of the full-scale model.

[0018] Preferably, in step S7, the signal source output size is adjusted to simulate the objective function of the vibration radiation noise information of the full-scale model under different levels of conditions, and by changing the signal source output amplitude size, the measured hydrophone self-noise level of each 1 Hz bandwidth at 1 kHz is made to reach 116 dB ± 2 dB, 110 dB ± 2 dB and 104 dB ± 2 dB respectively, which are defined as the excitation intensity as working conditions 1, 2, and 3. The three vibration intensities are used to simulate the radiation sound field of the full-scale model under different working conditions.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention provides a vibration spectrum modulation control method based on an objective function, which adopts a local model to replace a full-scale model. The use of the local model not only solves the site limitation problem and the cost limitation, but also makes the test results of the local model and the full-scale model closer. Description of the drawings:

[0021] Figure 1 A schematic diagram of an experimental flow of a vibration spectrum modulation control method based on an objective function according to an embodiment of the present invention;

[0022] Figure 2 A schematic diagram of an experimental system for a vibration spectrum modulation control method based on an objective function according to an embodiment of the present invention;

[0023] Figure 3 A test hydrophone power spectrum of a vibration spectrum modulation control method based on an objective function according to an embodiment of the present invention;

[0024] Figure 4 The power spectra of a hydrophone are tested under three working conditions of a vibration spectrum modulation control method based on an objective function in an embodiment of the present invention. Specific implementation method:

[0025] The present invention will be further described below with reference to the accompanying drawings:

[0026] The present invention provides a vibration spectrum control method based on an objective function, which controls the vibration test of a local model based on an objective function to solve the problem that the scaled model cannot replace the full-scale model test. Specifically, the present invention realizes the vibration radiation noise modeling of the full-scale model by controlling the output of multiple exciters. The test process of this method is as follows: Figure 1 The test system is as shown in Figure 2 As shown, the specific steps are as follows:

[0027] S1. Construct an objective function to obtain the vibration radiation noise information of the full-scale model;

[0028] S2, constructing a signal source function based on the target function model;

[0029] S3, the signal source output controls the output of the exciter after passing through the power amplifier;

[0030] S4, 6 vibrators stimulate the local hull model, and hydrophones monitor the radiated sound field of the model;

[0031] S5, comparing the frequency spectrum characteristics of the sound field signal monitored by the hydrophone with the target function;

[0032] S6. If the objective function is not met, the control signal source is output until the monitoring hydrophone signal spectrum is consistent with the objective function;

[0033] S7, adjusting the output of the signal source to simulate the vibration radiation noise information of the full-scale model under different levels of conditions. As a preferred embodiment, the material parameters used for fitting in step 3 can also be the sound absorption coefficient and the transmission coefficient.

[0034] As a preferred method, the objective function for obtaining the vibration radiation noise information of the full-scale model constructed in step S1 is a characteristic spectrum: it has the characteristics of a white spectrum in the frequency band of 200Hz to 800Hz; an attenuation of about 20dB per octave in the range of 1000Hz to 2000Hz; and a vibro-acoustic response spectrum with an attenuation of about 15dB per octave above 4000Hz.

[0035] In this embodiment, in steps S3-S4, the output of the signal source controls the output of the vibrator after passing through a power amplifier; this is done by using a vibro-acoustic system to generate 6 signals (with a bandwidth range of 1000Hz-8400Hz), which are amplified by 6 power amplifiers and used as the input of the vibrator. The output of the vibrator drives the 6 vibrators installed in the local model to work, thereby exciting the platform to generate structural vibration.

[0036] As a preferred method, in step S5, the spectrum characteristics of the sound field signal monitored by the hydrophone are compared with the objective function, by connecting the suspended hydrophone 15 cm away from the local model surface to the signal collector, setting the dynamic analysis bandwidth to 6400 Hz, the spectrum width to about 1 Hz, recording the radiated noise spectrum, and the signal collector performs multiple signal collection, analysis, and averaging until the vibration noise response received by the hydrophone is basically smooth and stable. The vibration noise response spectrum of the local model is analyzed with the expected noise response spectrum of the objective function, and a comparative operation analysis is performed to obtain the modified platform excitation noise spectrum.

[0037] As a preferred method, in step S6, different outputs of the signal source function are controlled according to the monitoring signal spectrum of the hydrophone, the signal source function corresponds to the input signals of different exciters, the input signals of the exciters at different positions are switched, and the output excitations of the exciters at different positions are controlled at the same time so that the radiated sound field of the local model meets the objective function of the vibration radiation noise information of the full-scale model.

[0038] In addition, in step S7, the signal source output size can be adjusted to simulate the objective function of the vibration radiation noise information of the full-scale model under different levels of conditions. Figure 3 Taking the test hydrophone with the power spectrum shown in the figure as an example, by changing the output amplitude of the signal source, the self-noise level of the measured hydrophone at 1KHz and each 1Hz bandwidth reaches 116dB±2dB, 110dB±2dB and 104dB±2dB respectively, which are defined as the excitation intensity as working conditions 1, 2 and 3. The three vibration intensities are used as the radiation sound fields of the full-scale model under different working conditions. Figure 4 shown.

[0039] It should be noted that, in step S4, if other excitation methods are adopted or the placement position and excitation method of the exciter are changed, the vibration simulation of the objective function can also be achieved.

[0040] In step S5, the hydrophone may monitor the sound field signal by using a vibration sensor or other sensor settings to compare with the target function to achieve the monitoring function of the vibration sound field.

[0041] The embodiment of the present invention provides a vibration spectrum modulation control method based on an objective function, which adopts a local model to replace the full-scale model. The use of the local model not only solves the site limitation problem and the cost limitation, but also makes the test results of the local model and the full-scale model closer, thereby realizing the vibration simulation test of the full-scale acoustic array.

[0042] The above is only an explanation of the preferred embodiments of the present invention, which should not be construed as a limitation on the claims. Any equivalent process changes made using the present invention specification are included in the patent protection scope of the present invention.

Claims

1. A vibration spectrum control method based on an objective function, which realizes vibration radiation noise modeling of a full-scale model by controlling the output of multiple exciters, characterized in that: The following steps are included: S1. Construct an objective function to obtain the vibration radiation noise information of the full-scale model; S2, constructing a signal source function based on the target function model; S3, the signal source output controls the output of the exciter after passing through the power amplifier; S4, multiple vibrators excite the local hull model, and hydrophones monitor the radiated sound field of the model; S5, comparing the frequency spectrum characteristics of the sound field signal monitored by the hydrophone with the target function; S6. If the objective function is not met, the control signal source is output until the monitoring hydrophone signal spectrum is consistent with the objective function; S7. Adjust the output size of the signal source to simulate the vibration radiation noise information of the full-scale model under different levels of conditions.

2. The vibration spectrum modulation control method based on the objective function according to claim 1 is characterized in that: The objective function for obtaining the vibration radiation noise information of the full-scale model constructed in step S1 is a characteristic spectrum: it has the characteristics of a white spectrum in the frequency band of 200Hz to 800Hz; an attenuation of about 19-21dB per octave in the range of 1000Hz to 2000Hz; and a vibro-acoustic response spectrum with an attenuation of 14-16dB per octave above 4000Hz.

3. The vibration spectrum modulation control method based on the objective function according to claim 1 is characterized in that: In steps S3-S4, the output of the signal source controls the output of the vibrator after passing through a power amplifier; this is done by using a vibro-acoustic system to generate 6 signals, which are amplified by 6 power amplifiers as input to the vibrator. The vibrator output drives the 6 vibrators installed in the local model to work, thereby stimulating the platform to generate structural vibration.

4. The vibration spectrum modulation control method based on the objective function according to claim 4 is characterized in that: The bandwidth of the generated 6-channel signals ranges from 1000Hz to 8400Hz.

5. The vibration spectrum modulation control method based on the objective function according to claim 1 is characterized in that: In step S5, comparing the frequency spectrum characteristics of the acoustic field signal monitored by the hydrophone with the objective function means that a suspended hydrophone 15 cm away from the local model surface is connected to a signal collector, a dynamic analysis bandwidth of 6400 Hz and a spectrum width of about 1 Hz are set, and the radiated noise spectrum is recorded. The signal collector performs multiple signal collection, analysis, and averaging until the vibration noise response received by the hydrophone is basically smooth and stable; And analyze the local model vibration noise response spectrum and the expected objective function noise response spectrum, and make comparative analysis to obtain the modified platform excitation noise spectrum.

6. The vibration spectrum modulation control method based on the objective function according to claim 1 is characterized in that: In step S6, according to the monitoring signal spectrum of the hydrophone, different outputs of the signal source function are controlled. The signal source function corresponds to the input signals of different exciters. The input signals of the exciters at different positions are switched, and the output excitations of the exciters at different positions are controlled at the same time so that the radiated sound field of the local model meets the objective function of the vibration radiation noise information of the full-scale model.

7. The vibration spectrum modulation control method based on the objective function according to claim 1 is characterized in that: In step S7, the signal source output size is adjusted to simulate the objective function of the vibration radiation noise information of the full-scale model under different levels of conditions, and by changing the signal source output amplitude size, the measured hydrophone self-noise level of each 1 Hz bandwidth at 1 kHz is made to reach 116 dB ± 2 dB, 110 dB ± 2 dB and 104 dB ± 2 dB respectively, which are defined as the excitation intensity as working conditions 1, 2, and 3. The three vibration intensities are used to simulate the radiation sound field of the full-scale model under different working conditions.

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