Sound source vibration detection system

Abstract

The utility model discloses a sound source vibration detection system, which comprises a light source module, a photoelectric detection module, a light interference module, a pickup module, a vibration optical fiber modulation enhancement module and a signal processing module, the vibration optical fiber modulation enhancement module is divided into three layers from inside to outside, the sensing optical fiber is wound on the first layer, the first reflector is connected with one output port of the optical interference module through the sensing optical fiber, and the first layer is filled with vibration enhancement glue; the reference optical fiber is coiled on the second layer, the second reflector is connected with the other output port of the optical interference module through the reference optical fiber, and the second layer is filled with vibration suppression glue; and the third layer is filled with high-frequency vibration absorption glue. The utility model relates to the technical field of optical fiber sensing, and the vibration optical fiber modulation enhancement module is divided into three layers from inside to outside, so that the fixed-point detection of a sound vibration source and the suppression processing of noise transmitted by ambient air can be realized, and the acquisition quality and effect of vibration signals generated by the vibration source can be improved.

Description

Technical Field

[0001] This utility model belongs to the field of fiber optic sensing technology, specifically to a sound source vibration detection system. Background Technology

[0002] With the continuous improvement of informatization, more and more scenarios require the detection of physical quantities such as sound through sound sensors, followed by data collection, analysis, judgment, and storage in computer systems. This intelligent approach replaces traditional manual on-site sound processing. Different environments, such as air, underwater, and pipe corridors, typically have different noise levels, frequency ranges, and operating temperature requirements. Furthermore, different types of sound sensors have different characteristics and applicable ranges, necessitating different types of sound sensors for different environments. Among these, fiber optic sound sensors, due to their passive nature, small size, long lifespan, corrosion resistance, and electromagnetic interference resistance, along with high sensitivity, large dynamic range, and wide detection frequency, are widely applicable in harsh environments such as humid, highly acidic / alkaline, or complex air compositions, and have thus attracted extensive research and attention. Currently, applying fiber optic sound sensing systems to sound source vibration detection and reconstruction is a crucial research direction for high-sensitivity sensors.

[0003] A search of existing technical literature revealed that Chinese Patent CN101504312A discloses a fiber optic sound sensor for sound detection. This prior art utilizes a combination of a diaphragm and optical fiber to achieve sound sensing. Specifically, the light signal reflected by the diaphragm is received by the receiving optical fiber and transmitted to a subsequent photodetector for photoelectric conversion. The converted electrical signal is then processed by a signal processing circuit to reconstruct the sound signal. Wang Yongjie et al.'s publication, titled "Michelson Interferometer Fiber Optic Airborne Sound Sensor," describes a fiber optic airborne sound sensor based on the principle of a fiber optic Michelson interferometer, combining the stress and strain of an elastic disk and fiber optic bonding to achieve airborne sound sensing. Chinese Patent CN113029217A discloses a fiber optic sound sensing system and optical microphone based on a Fabry-Poirot etalon. This prior art uses a directly coupled optical microphone based on the Fabry-Poirot etalon to convert sound signals into light signals for transmission.

[0004] However, in using the above-mentioned prior art, the inventors discovered at least the following problems:

[0005] The aforementioned existing technologies do not perform point-to-point detection of the mechanical vibration of the sound source during implementation, nor do they suppress noise transmitted through the air, resulting in the need to improve the quality and effect of the sound source vibration signal. Utility Model Content

[0006] To address the aforementioned problems in the existing technology, this utility model provides a sound source vibration detection system, which features high sensitivity to sound source vibration signals, wide frequency response detection, and high signal-to-noise ratio.

[0007] The technical solution adopted in this utility model is as follows: a sound source vibration detection system, including a light source module, a photoelectric detection module, an optical interference module, a sound pickup module, a vibration fiber modulation enhancement module, and a signal processing module; the light source module emits coherent light as a carrier for sound vibration signal acquisition and transmission; the photoelectric detection module includes a first photodetector and a second photodetector; the optical interference module uses an optical fiber coupler; the sound pickup module includes a first reflector and a second reflector; the vibration fiber modulation enhancement module includes a sensing fiber, a reference fiber, vibration enhancing adhesive, vibration suppressing adhesive, and high-frequency vibration absorbing adhesive.

[0008] The vibration fiber modulation enhancement module consists of three layers from the inside out. The sensing fiber is coiled in the first layer, and the first reflector is connected to one output port of the optical interference module through the sensing fiber. The first layer is filled with vibration enhancement adhesive. The reference fiber is coiled in the second layer, and the second reflector is connected to another output port of the optical interference module through the reference fiber. The second layer is filled with vibration suppression adhesive. The third layer is filled with high-frequency vibration absorption adhesive.

[0009] Furthermore, the light source module is connected to the optical interference module, the input port of the optical interference module is connected to the photoelectric detection module, the output port of the optical interference module is connected to the vibration fiber modulation enhancement module, and the vibration fiber modulation enhancement module is connected to the sound pickup module. The optical interference module, the sound pickup module, and the vibration fiber modulation enhancement module are encapsulated together. The photoelectric detection module is connected to the signal processing module, which analyzes and processes the received information and outputs the sound.

[0010] Furthermore, the vibration fiber modulation enhancement module also includes a housing, a base plate installed at the bottom of the housing, a partition plate inside the housing fixedly connected to the base plate, a liner plate inside the partition plate also fixedly connected to the base plate, the sensing fiber and the first reflector coiled on the base plate, vibration enhancement adhesive filling the space between the base plate and the liner plate, the reference fiber and the second reflector coiled on the liner plate, vibration suppression adhesive filling the space between the liner plate and the partition plate, and high-frequency vibration absorption adhesive filling the space between the housing and the partition plate.

[0011] Furthermore, the housing is provided with an optical cable interface, which passes through the partition and the liner in sequence. An extension optical cable is installed inside the optical cable interface. The extension optical cable is equipped with three optical fiber connectors in conjunction with the light source, the first photodetector, and the second photodetector. The three input ports of the optical interference module are respectively connected to the three extension optical cables.

[0012] Furthermore, the light source module is connected to the input port of the optical interference module via a transmitting optical fiber, and the first photodetector and the second photodetector are respectively connected to the other two input ports of the optical interference module via different receiving optical fibers. The signal acquisition end of the signal processing module is connected to the first photodetector and the second photodetector respectively. The vibration fiber modulation enhancement module is connected to the optical interference module via two optical fibers, a sensing fiber and a reference fiber, to realize the carrier transmission into the modulation module and the feedback of the modulated carrier to the optical interference module.

[0013] Furthermore, the vibration-enhancing adhesive is a rigid adhesive; the vibration-suppressing adhesive is a flexible adhesive; and the high-frequency vibration-absorbing adhesive is a foamed adhesive with microcavities.

[0014] Furthermore, both the first and second photodetectors employ PIN photodiodes.

[0015] Furthermore, the light source is a semiconductor laser with a half-width at half-maximum of 10 MHz.

[0016] Furthermore, the shell, partition, and liner are all made of aluminum alloy.

[0017] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0018] This sound source vibration detection system divides the vibration fiber modulation enhancement module into three layers from the inside out, enabling the pinpoint detection of sound vibration sources and the suppression of noise transmitted through the ambient air, thereby improving the quality and effectiveness of vibration signal acquisition from the vibration source.

[0019] Because the first layer of sensing fiber is coiled at the bottom of the module to fit closely with the vibration source, and the sensing fiber is fixed by vibration-enhancing adhesive, the sensing fiber will produce a significant photoelastic effect in the vibration-enhancing adhesive, which will enhance the sensitivity of the fiber optic acoustic sensing system to vibration signals. This will greatly improve the signal-to-noise ratio of the reproduced vibration signal, and give it the characteristics of wide frequency response and high sensitivity to mechanical vibration signals.

[0020] The light beam in the sensing fiber will generate a relative phase difference with the light beam in the reference fiber coiled in the second layer under the vibration of the vibration source. By adjusting this phase difference, the sound signal can be restored. At the same time, the reference fiber has undergone special treatment to reduce vibration sensitivity, and the ambient air vibration noise is reduced by the sound-absorbing layer in the third layer. This invention can solve the problem that traditional fiber optic acoustic sensors cannot shield air noise in complex environments. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A diagram illustrating the architecture of a sound source vibration detection system provided in this embodiment of the utility model;

[0023] Figure 2 A cross-sectional view of the vibration fiber modulation enhancement module provided in an embodiment of this utility model;

[0024] Figure 3 A top view of the liner provided in an embodiment of this utility model;

[0025] Figure 4 A top view of the base plate provided in an embodiment of this utility model.

[0026] Figure descriptions: 1. Housing; 2. Partition; 3. Liner; 4. Base plate; 5. Rigid adhesive; 6. Flexible adhesive; 7. Foam; 8. Sensing optical fiber; 9. Reference optical fiber; 10. First reflector; 11. Second reflector; 12. Optical cable interface; 13. Extension optical cable. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] In the description of this utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0030] The following is combined Figures 1-4 This utility model will be described in detail.

[0031] Example

[0032] like Figures 1-4 As shown, a sound source vibration detection system includes a light source module, a photoelectric detection module, an optical interference module, a sound pickup module, a vibration fiber modulation enhancement module, and a signal processing module. The light source module emits coherent light, which is used as a carrier for sound vibration signal acquisition and transmission. The photoelectric detection module includes a first photodetector and a second photodetector. The optical interference module uses an optical fiber coupler. The sound pickup module includes a first reflector 10 and a second reflector 11. The vibration fiber modulation enhancement module includes a sensing fiber 8, a reference fiber 9, vibration enhancing adhesive, vibration suppressing adhesive, and high-frequency vibration absorbing adhesive.

[0033] The vibration fiber modulation enhancement module consists of three layers from the inside out. The sensing fiber 8 is coiled in the first layer, and the first reflector 10 is connected to one output port of the optical interference module through the sensing fiber 8. This first layer is filled with vibration-enhancing adhesive, which increases the sensitivity to vibration sources. The reference fiber 9 is coiled in the second layer, and the second reflector 11 is connected to another output port of the optical interference module through the reference fiber 9. This second layer is filled with vibration-suppressing adhesive, which reduces the response of the reference fiber 9 to environmental vibrations. The third layer is filled with high-frequency vibration-absorbing adhesive, which absorbs high-frequency vibration noise transmitted through the air.

[0034] The vibration-enhancing adhesive is a rigid adhesive 5, specifically, in this embodiment, a casting adhesive. The vibration-suppressing adhesive is a flexible adhesive 6, specifically, in this embodiment, silicone rubber. The high-frequency vibration-absorbing adhesive is a foamed adhesive 7 with microcavities. It should be noted that this embodiment uses a polyurethane foaming agent, which contains microporous components, enabling the absorption of vibrations transmitted through the air.

[0035] The vibration fiber modulation enhancement module also includes a housing 1, a base plate 4 installed at the bottom of the housing 1, a partition 2 disposed inside the housing 1 and fixedly connected to the base plate 4, a liner 3 disposed inside the partition 2 and fixedly connected to the base plate 4, a sensing fiber 8 and a first reflector 10 coiled on the base plate 4, vibration enhancement adhesive filling the space between the base plate 4 and the liner 3, a reference fiber 9 and a second reflector 11 coiled on the liner 3, vibration suppression adhesive filling the space between the liner 3 and the partition 2, and high-frequency vibration absorption adhesive filling the space between the housing 1 and the partition 2.

[0036] It should be noted that by setting partition 2 and liner 3 inside the shell 1, the shell 1 is divided into three layers from the inside to the outside. Partition 2 and liner 3 can be fixed to the base plate 4 by bolts and nuts, and the shell 1 can be fixed to the base plate 4 by welding.

[0037] The housing 1 has an optical cable interface 12, which passes through the partition 2 and the liner 3. An extension optical cable 13 is installed inside the optical cable interface 12. The extension optical cable 13 is equipped with three fiber optic connectors in conjunction with the light source, the first photodetector, and the second photodetector. The three input ports of the optical interference module are respectively connected to the three extension optical cables 13. It should be noted that the optical cable interface 12 facilitates the passage of the extension optical cable 13 through the housing 1.

[0038] In this embodiment, the light source module is connected to the optical interference module, the input port of the optical interference module is connected to the photoelectric detection module, the output port of the optical interference module is connected to the vibration fiber modulation enhancement module, the vibration fiber modulation enhancement module is connected to the sound pickup module, the optical interference module and the sound pickup module are encapsulated with the vibration fiber modulation enhancement module, the photoelectric detection module is connected to the signal processing module, the signal processing module analyzes and processes the received information, and outputs the sound.

[0039] Specifically, the light source module is connected to the input port of the optical interference module via a transmitting optical fiber, providing a coherent optical carrier for the entire system.

[0040] The first photodetector and the second photodetector are connected to the other two input ports of the optical interference module through different receiving optical fibers, respectively, and transmit the converted electrical signals to the signal processing module. The signal acquisition end of the signal processing module is connected to the first photodetector and the second photodetector respectively.

[0041] The vibration fiber modulation enhancement module is connected to the optical interference module through two optical fibers, sensing fiber 8 and reference fiber 9, to realize the carrier transmission into the modulation module and the feedback of the modulated carrier to the optical interference module. The three-layer structure from the inside to the outside and the colloid filling method are designed as described above to ensure effective modulation of the vibration signal and suppression of environmental noise.

[0042] The first reflector 10 and the second reflector 11 are connected to the output port of the optical interference module through the sensing fiber 8 and the reference fiber 9, respectively, to complete the reflection of the optical signal and the generation of phase difference.

[0043] The optical interference module and the sound pickup module are packaged with the vibration fiber modulation enhancement module to ensure system integration and stability. The photoelectric detection module is connected to the signal processing module, which analyzes and processes the acquired electrical signals to finally output a clear sound signal.

[0044] In this embodiment, both the first and second photodetectors employ PIN photodiodes. It should be noted that PIN photodiodes can convert received optical signals into electrical signals, and they possess advantages such as simple structure, high sensitivity, and fast response.

[0045] In this embodiment, the light source is a semiconductor laser with a half-width at half-maximum (HWHM) of 10 MHz. Specifically, the light source uses a semiconductor laser with a HWHM of approximately 10 MHz, which gives the light source the advantage of low phase and intensity noise of the detected light wave.

[0046] In this embodiment, the shell 1, partition 2, and liner 3 are all made of aluminum alloy. It should be noted that the use of aluminum alloy is advantageous because aluminum alloy is environmentally friendly, durable, and inexpensive, thus facilitating the expansion of the application scenarios of this embodiment and extending product lifespan.

[0047] Specifically, when using this sound source vibration detection system, the coherent light emitted by the light source module first enters the optical interference module. The optical interference module splits the optical signal into two paths, which are transmitted to the reflector of the pickup module through sensing fiber 8 and reference fiber 9, respectively. When the sound source vibrates, sensing fiber 8 (located in the first layer of the vibration fiber modulation enhancement module and filled with vibration-enhancing adhesive) is affected by the vibration, and the phase of the beam inside it changes significantly. Reference fiber 9 (located in the second layer and filled with vibration-suppressing adhesive) is less affected by the vibration, mainly reflecting the influence of environmental factors on the phase of the optical signal. Due to the high-frequency vibration-absorbing adhesive in the third layer of the vibration fiber modulation enhancement module, most of the high-frequency vibration noise in the environment is effectively absorbed, reducing its impact on the pickup module.

[0048] The two optical signals, after being reflected by the mirror, return to the optical interferometer module. Due to differences in the environment of the different optical fibers and the varying degrees of vibration they are subjected to, a phase difference arises between the two signals. The optical interferometer module uses the principle of interference to synthesize and process the two optical signals, converting the phase difference information into a light intensity change signal. This light intensity change signal carries characteristic information about the sound source vibration.

[0049] The processed optical signal enters the photoelectric detection module. The first and second photoelectric detectors convert the two optical signals into electrical signals, which are then transmitted to the signal processing module. The signal processing module uses advanced signal processing algorithms, such as filtering, amplification, and decoding, to analyze and process the electrical signal, remove noise interference, extract the pure sound source vibration signal characteristics, and finally convert it into a clear and distinguishable sound signal output, achieving effective detection and sound reconstruction of the sound source vibration.

[0050] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A sound source vibration detection system, characterized by: It includes light source module, photoelectric detection module, light interference module, pickup module, vibration fiber modulation enhancement module and signal processing module; the light source module emits coherent light, which is used as a carrier for sound vibration signal collection and transmission, the photoelectric detection module includes a first photoelectric detector and a second photoelectric detector, the light interference module uses a fiber coupler, the pickup module includes a first mirror (10) and a second mirror (11), the vibration fiber modulation enhancement module includes a sensing fiber (8), a reference fiber (9), a vibration enhancement glue, a vibration suppression glue and a high-frequency vibration absorption glue; The vibration fiber modulation enhancement module is divided into three layers from the inside to the outside, the sensing fiber (8) is coiled and arranged in the first layer, the first mirror (10) is connected through the sensing fiber (8) and one output port of the light interference module, and the first layer is filled with vibration enhancement glue; the reference fiber (9) is coiled and arranged in the second layer, the second mirror (11) is connected through the reference fiber (9) and the other output port of the light interference module, and the second layer is filled with vibration suppression glue; the third layer is filled with high-frequency vibration absorption glue.

2. The acoustic source vibration detection system of claim 1, wherein: The light source module is connected with the light interference module, the input port of the light interference module is connected with the photoelectric detection module, the output port of the light interference module is connected with the vibration fiber modulation enhancement module, the vibration fiber modulation enhancement module is connected with the pickup module, the light interference module and the pickup module are packaged with the vibration fiber modulation enhancement module, the photoelectric detection module is connected with the signal processing module, the signal processing module analyzes and processes the received information, and the sound is output.

3. The acoustic source vibration detection system of claim 1, wherein: The vibration fiber modulation enhancement module further includes a shell (1), a bottom plate (4) is mounted on the bottom of the shell (1), a partition plate (2) is arranged in the shell (1), the partition plate (2) is fixedly connected to the bottom plate (4), a lining plate (3) is arranged in the partition plate (2), and the lining plate (3) is also fixedly connected to the bottom plate (4), the sensing fiber (8) and the first mirror (10) are coiled and arranged on the bottom plate (4), the vibration enhancement glue fills between the bottom plate (4) and the lining plate (3), the reference fiber (9) and the second mirror (11) are coiled and arranged on the lining plate (3), and the vibration suppression glue fills between the lining plate (3) and the partition plate (2), and the high-frequency vibration absorption glue fills between the shell (1) and the partition plate (2).

4. A sound source vibration detection system according to claim 3, characterised in that: An optical cable interface (12) is formed on the shell (1), and the optical cable interface (12) penetrates the partition plate (2) and the lining plate (3) in sequence, an extension optical cable (13) is mounted in the optical cable interface (12), the extension optical cable (13) is provided with three optical fiber joints matched with the light source, the first photoelectric detector and the second photoelectric detector, and three input ports of the light interference module are connected with the three extension optical cables (13).

5. The acoustic source vibration detection system of claim 1, wherein: The light source module is connected with the input port of the light interference module through an emitting optical fiber, the first photoelectric detector and the second photoelectric detector are respectively connected with the other two input ports of the light interference module through different receiving optical fibers, the signal acquisition end of the signal processing module is connected with the first photoelectric detector and the second photoelectric detector, and the vibration optical fiber modulation enhancement module is connected with the light interference module through the sensing optical fiber (8) and the reference optical fiber (9), so that the carrier transmission is realized into the modulation module and the modulated carrier is fed back to the light interference module.

6. The acoustic source vibration detection system of claim 1, wherein: The vibration enhancement glue adopts rigid glue (5); the vibration suppression glue adopts flexible glue (6); and the high-frequency vibration absorption glue adopts foaming glue (7) with microcavities.

7. The acoustic source vibration detection system of claim 1, wherein: The first photoelectric detector and the second photoelectric detector both adopt PIN photoelectric diodes.

8. The acoustic source vibration detection system of claim 1, wherein: The light source adopts a semiconductor laser with a half-height width of 10 MHz.

9. The acoustic source vibration detection system of claim 3, wherein: The materials of the shell (1), the partition plate (2) and the lining plate (3) are all aluminum alloys.

Images