A multi-dimensional vibration sensor based on a multi-core optical fiber and a vibration detection method

Abstract

The application provides a multi-dimensional vibration sensor based on a multi-core optical fiber and a vibration detection method. The multi-dimensional vibration sensor comprises a light source module, a vibration multi-core optical fiber, a fan-out module and a vibration signal detection module. One end of the light source module is arranged in a spaced manner opposite to one end of the vibration multi-core optical fiber in the axial direction, so as to transmit the light signal of the light source module to each core of the vibration multi-core optical fiber. The one end of the vibration multi-core optical fiber in the axial direction can generate multi-dimensional displacement when the multi-dimensional vibration sensor vibrates. The other end of the vibration multi-core optical fiber is connected to one end of the fan-out module, so as to respectively output the light signals received by each core of the vibration multi-core optical fiber. The other end of the fan-out module is connected to one end of the vibration signal detection module, so as to output the light intensity of the light signals of each core through the vibration signal detection module. The above-mentioned sensor can accurately, sensitively and in real time detect complex multi-dimensional vibration.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and in particular to a multidimensional vibration sensor and vibration detection method based on multi-core optical fiber. Background Technology

[0002] Vibration detection can be used to monitor and warn of structural health conditions of large buildings, operational status of machinery, natural disaster early warning, and remote healthcare. Currently, piezoelectric accelerometers are commonly used for vibration detection, but these sensors require electrical isolation, and to achieve high-sensitivity detection, they need large piezoelectric dimensions on the order of centimeters, resulting in very low spatial resolution.

[0003] In recent years, fiber optic sensors have attracted widespread attention due to their inherent non-conductive properties, resistance to electromagnetic interference, and high sensitivity. Furthermore, fiber optic sensors also offer advantages such as small size, light weight, low cost, and ease of remote monitoring.

[0004] Based on the modulation method of the light by the measured object, fiber optic sensors can be divided into phase-modulated and intensity-modulated types. Phase-modulated sensors use various phase interferometers to detect vibrations. These sensors have high sensitivity and accuracy, but are easily affected by temperature and other low-frequency ambient noise. Intensity-modulated sensors utilize the vibration signal to modulate the coupling efficiency of transmitted or reflected light, thereby achieving vibration measurement.

[0005] The aforementioned types of sensors mainly focus on processing one-dimensional vibration data. However, in actual vibration detection scenarios, there is a wide variety of complex multi-dimensional (directional) vibration data. Relying on the aforementioned individual sensors makes it difficult to achieve accurate, highly sensitive, and real-time vibration detection.

[0006] Therefore, a multidimensional vibration sensing device capable of accurate, highly sensitive, and real-time detection of multidimensional vibrations has become an urgent need for vibration detection. Summary of the Invention

[0007] To address the aforementioned technical problems, this application provides a multidimensional vibration sensor and vibration detection method based on multi-core optical fiber, which can be used for accurate, highly sensitive, and real-time vibration detection of complex multidimensional vibrations.

[0008] On the one hand, embodiments of this application provide a multidimensional vibration sensor based on multi-core optical fiber, which includes: a light source module, a vibrating multi-core optical fiber, a fan-out module, and a vibration signal detection module.

[0009] One end of the light source module is spaced apart from the axial end of the vibrating multi-core optical fiber to transmit the optical signal from the light source module to each core of the vibrating multi-core optical fiber. The axial end of the vibrating multi-core optical fiber can generate multi-dimensional displacement when the multi-dimensional vibration sensor vibrates. The other axial end of the vibrating multi-core optical fiber is connected to one end of a fan-out module to output the optical signals received by each core of the vibrating multi-core optical fiber. The other end of the fan-out module is connected to one end of a vibration signal detection module to output the optical intensity of the optical signal from each core.

[0010] In one implementation of this application, the light source module includes: a laser light source unit and a first single-mode optical fiber. One end of the laser light source unit is connected to one axial end of the first single-mode optical fiber. The other axial end of the first single-mode optical fiber serves as one end of the light source module.

[0011] In one implementation of this application, the fan-out module includes: a multi-core optical fiber connected to the vibrating multi-core optical fiber, and multiple output ports. The multi-core optical fiber is connected to the other end of the vibrating multi-core optical fiber along its axis to receive optical signals, and each output port outputs an optical signal to the vibration signal detection module.

[0012] In one implementation of this application, the vibration signal detection module includes: multiple second single-mode optical fibers, multiple photodetectors, and multiple oscilloscopes. One end of each second single-mode optical fiber serves as one end of the vibration signal detection module. The other end of each second single-mode optical fiber is connected to one end of each photodetector. Each second single-mode optical fiber corresponds one-to-one with a photodetector. The other end of each photodetector is connected to the input terminal of each oscilloscope, thus corresponding to both the photodetector and the oscilloscope.

[0013] In one implementation of this application, the number of multiple output ports is the same as the number of cores in a vibrating multi-core optical fiber.

[0014] In one implementation of this application, the number of multiple second single-mode optical fibers, multiple photodetectors, and multiple oscilloscopes are the same as the number of fiber cores in the vibrating multi-core optical fiber.

[0015] In one implementation of this application, the cores of the vibrating multi-core optical fiber have the same core diameter as the first single-mode optical fiber.

[0016] In one implementation of this application, the vibrating multi-core optical fiber is a weakly coupled optical fiber.

[0017] In one implementation of this application, the spacing between the cores of the vibrating multi-core optical fiber is smaller than the core diameter of each core.

[0018] On the other hand, embodiments of this application also provide a vibration detection method based on a multi-core optical fiber multidimensional vibration sensor, the method comprising:

[0019] The vibrating multi-core optical fiber receives optical signals emitted by the light source module in either a static or vibrating state. The vibrating multi-core optical fiber transmits the optical signal to the fan-out module through its respective cores. The fan-out module, based on the fiber from which the optical signal was acquired, outputs the optical signal to the vibration signal detection module, which then outputs the light intensity of each core's optical signal.

[0020] This application, through the aforementioned multidimensional vibration sensor, enables the reception of optical signals emitted by a light source module via a vibrating multi-core optical fiber under both vibrating and stationary conditions. The optical signals from different fiber cores are then transmitted to a vibration signal detection module via a fan-out module. Each fiber core of the vibrating multi-core optical fiber receives a different optical signal and transmits it separately, resulting in different light intensities received by the vibration signal detection module. Vibration detection is achieved through the detection of light intensity. Furthermore, the multidimensional vibration sensor and corresponding vibration detection method provided in this application are less susceptible to temperature and other low-frequency environmental noise, enabling accurate, highly sensitive, and real-time detection of multidimensional (three-dimensional) vibrations. Attached Figure Description

[0021] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0022] Figure 1 This is a schematic diagram of a multi-dimensional vibration sensor based on multi-core optical fiber in an embodiment of this application;

[0023] Figure 2 This is a schematic diagram of the light source module of a multi-dimensional vibration sensor based on multi-core optical fiber in an embodiment of this application;

[0024] Figure 3 This is a cross-sectional schematic diagram of the vibration multi-core optical fiber of a multi-dimensional vibration sensor based on multi-core optical fiber in an embodiment of this application.

[0025] Figure 4 This is a schematic diagram of another structure of a multi-dimensional vibration sensor based on multi-core optical fiber in an embodiment of this application;

[0026] Figure 5 This is a schematic flowchart of a vibration detection method based on a multi-core optical fiber multidimensional vibration sensor according to an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] This application provides a multidimensional vibration sensor and vibration detection method based on multi-core optical fiber, which can be used to accurately, sensitively and in real time detect complex multidimensional vibrations.

[0029] The various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0030] This application provides a multidimensional vibration sensor based on multi-core optical fiber, such as... Figure 1 As shown, the multidimensional vibration sensor 100 based on multi-core optical fiber includes at least: a light source module 110, a vibration multi-core optical fiber 120, a fan-out module 130, and a vibration signal detection module 140.

[0031] One end of the light source module 110 is spaced apart from one axial end of the vibrating multi-core optical fiber 120 to transmit the optical signal from the light source module 110 to each core of the vibrating multi-core optical fiber 120. The axial end of the vibrating multi-core optical fiber 120 can generate multi-dimensional displacement when the multi-dimensional vibration sensor 100 vibrates. The other axial end of the vibrating multi-core optical fiber 120 is connected to one end of the fan-out module 130 to output the optical signals received by each core of the vibrating multi-core optical fiber 120. The other end of the fan-out module 130 is connected to one end of the vibration signal detection module 140 to output the light intensity of the optical signal from each core.

[0032] In some embodiments of this application, such as Figure 2 As shown, the multidimensional vibration sensor 100 may include a housing 210, and a light source module 110 fixed inside the housing 210 on one side. When the multidimensional vibration sensor 100 vibrates, the light source module 110 will vibrate synchronously with the multidimensional vibration sensor 100; while the vibrating multi-core optical fiber 120 can freely perform multidimensional displacement vibration according to the vibration of the multidimensional vibration sensor 100. This multidimensional displacement includes at least: front-back displacement, left-right displacement, and up-down displacement. It should be noted that front-back, left-right, and up-down can be understood as... Figure 2 The coordinate axis directions in the three-dimensional space shown are for the placement of the multidimensional vibration sensor in this application. However, this application does not limit the multidimensional displacement to the displacement directions exemplified above. Forward, backward, left, right, up, and down cannot limit the setting or use direction of the multidimensional vibration sensor in this application.

[0033] In some embodiments of this application, the multidimensional vibration described herein includes at least one-dimensional vibration, two-dimensional vibration, and three-dimensional vibration. One-dimensional vibration can be understood as vibration in a single direction that existing sensors can detect. The multidimensional vibration sensor of this application can detect vibration in at least three directions.

[0034] In some embodiments of this application, the vibrating multi-core optical fiber 120 is preferably a seven-core optical fiber, and each core has the same core diameter, such as... Figure 3 The image shows a cross-sectional view of one end of the axial direction of the vibrating multi-core optical fiber 120 when it is a seven-core optical fiber.

[0035] refer to Figure 4 In this embodiment of the application, the light source module 110 includes: a laser light source unit 111 and a first single-mode optical fiber 112.

[0036] One end of the laser light source unit 111 is connected to one axial end of the first single-mode fiber 112. The other axial end of the first single-mode fiber 112 serves as one end of the light source module 110.

[0037] In some embodiments of this application, the laser light source unit 111 may be a single-frequency light source or a broadband light source, and this application does not specifically limit this.

[0038] In some embodiments of this application, each core of the vibrating multi-core optical fiber 120 has the same core diameter as the first single-mode optical fiber 112.

[0039] In some embodiments of this application, when stationary, the first single-mode fiber 112 and the intermediate fiber core (301) of the vibrating multi-core fiber 120 are relatively spaced apart. This relative spacing means that they are aligned in the ray direction of the first single-mode fiber 112 and have a certain distance between them (not in contact). The first single-mode fiber 112 couples the laser emitted by the laser source unit 111. When stationary, only the intermediate fiber core of the vibrating multi-core fiber 120 can detect the optical signal. When subjected to external vibration and multi-dimensional displacement of the vibrating multi-core fiber, different vibration directions cause different fiber cores of the vibrating multi-core fiber 120 to be aligned in the ray direction of the first single-mode fiber 112, thereby enabling different fiber cores of the vibrating multi-core fiber 120 to output optical signals. Vibration detection is then performed based on the light intensity output by different fiber cores.

[0040] In this embodiment, the fan-out module 130 includes: a multi-core optical fiber 131 connected to the vibrating multi-core optical fiber 120, and multiple output ports 132.

[0041] The multi-core optical fiber 131 is connected to the other end of the vibrating multi-core optical fiber 120 along the axis to receive optical signals and to output optical signals to the vibration signal detection module 140 through each output port 132.

[0042] In some embodiments of this application, one end of the fan-out module 130 is a multi-core optical fiber 131, and the other end has multiple output ports 132 that can split the optical signals of each core of the multi-core optical fiber 131 to different single-mode optical fibers and output them to the vibration signal detection module 140.

[0043] In some embodiments of this application, the number of multiple output ports 132 is the same as the number of each core of the vibrating multi-core optical fiber 120.

[0044] For example, if the vibrating multi-core fiber 120 is a seven-core fiber, then the output port 132 has 7 ports.

[0045] Through the aforementioned fan-out module 130, different optical signals received by each core of the vibrating multi-core optical fiber 120 during the displacement process can be transmitted separately, thereby enabling the vibration signal detection module 140 to receive different light intensities, so as to achieve the purpose of vibration detection through the detection of light intensity.

[0046] In this embodiment, the vibration signal detection module 140 includes: multiple second single-mode optical fibers 141, multiple photodetectors 142, and multiple oscilloscopes 143.

[0047] One end of each second single-mode fiber 141 serves as one end of the vibration signal detection module 140. The other end of each second single-mode fiber 141 is connected to one end of each photodetector 142. There is a one-to-one correspondence between the second single-mode fiber 141 and the photodetector 142. The other end of each photodetector 142 is connected to the input terminal of each oscilloscope 143, with each photodetector 142 corresponding to one oscilloscope 143.

[0048] In some embodiments of this application, the number of multiple second single-mode optical fibers 141, multiple photodetectors 142, and multiple oscilloscopes 143 are the same as the number of each fiber core of the vibrating multi-core optical fiber 120.

[0049] Specifically, such as Figure 4 As shown, the one-to-one correspondence between the second single-mode fiber 141 and the photodetector 142 means that one second single-mode fiber 141 has one and only one photodetector 142 connected to it; similarly, the correspondence between the photodetector 142 and the oscilloscope 143 means that one photodetector 142 has at least one oscilloscope 143 connected to it to receive its optical signal. Specifically, when the oscilloscope has multiple channels, multiple photodetectors can be connected to the same oscilloscope, that is, one photodetector is connected to one channel of the oscilloscope.

[0050] In this embodiment, the vibrating multi-core optical fiber 120 is a weakly coupled optical fiber.

[0051] Using weakly coupled optical fibers ensures that the light transmitted between each fiber core cannot couple with each other.

[0052] In this embodiment of the application, the spacing between the cores of the vibrating multi-core optical fiber 120 is smaller than the core diameter of each core.

[0053] On the other hand, this application also provides a vibration detection method based on a multi-core optical fiber multidimensional vibration sensor, such as... Figure 5 As shown, the method includes the following steps:

[0054] S501, a vibrating multi-core optical fiber, receives optical signals emitted by the light source module when the device is stationary or vibrating.

[0055] S502, a vibrating multi-core optical fiber, transmits optical signals to the fan-out module through its respective cores.

[0056] S503, the fan-out module outputs optical signals to the vibration signal detection module according to the corresponding optical fiber from which the optical signal is acquired, so that the vibration signal detection module can output the light intensity of the optical signal of each fiber core.

[0057] In this embodiment, the vibration signal detection module outputs the light intensity of the optical signal received by different cores of the vibrating multi-core optical fiber through its oscilloscope. By observing the light intensity displayed on the oscilloscope and detecting the changes in light intensity of each core, the vibration direction is determined, thereby achieving vibration sensing in at least three dimensions. Furthermore, the multi-dimensional vibration sensor and vibration detection method provided in this application are not easily affected by temperature or other low-frequency environmental noise.

[0058] The various embodiments in this application are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0059] The devices and methods provided in this application are one-to-one correspondences. Therefore, the devices also have similar beneficial technical effects as their corresponding methods. Since the beneficial technical effects of the multidimensional vibration sensor have been described in detail above, the beneficial technical effects of its vibration detection method will not be repeated here.

[0060] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A multidimensional vibration sensor based on multi-core optical fiber, characterized in that, The multidimensional vibration sensor includes: a light source module, a multi-core vibration optical fiber, a fan-out module, and a vibration signal detection module; One end of the light source module is spaced apart from the axial end of the vibrating multi-core optical fiber so as to transmit the optical signal of the light source module to each core of the vibrating multi-core optical fiber; wherein, the axial end of the vibrating multi-core optical fiber can generate multi-dimensional displacement when the multi-dimensional vibration sensor vibrates, and the multi-dimensional displacement includes at least: front-back displacement, left-right displacement, and up-down displacement, where front-back, left-right, and up-down are the coordinate axis directions of the three-dimensional space when it is placed. The other axial end of the vibrating multi-core optical fiber is connected to one end of the fan-out module to output the optical signals received by each core of the vibrating multi-core optical fiber. The other end of the fan-out module is connected to one end of the vibration signal detection module so that the vibration signal detection module can output the light intensity of the optical signal of each fiber core. The light source module includes: a laser light source unit and a first single-mode optical fiber; One end of the laser source unit is connected to one axial end of the first single-mode optical fiber; The other end of the first single-mode fiber serves as one end of the light source module; the relative interval is set such that the two are located in the ray direction of the first single-mode fiber, and there is a certain distance between them; When the laser emitted by the first single-mode fiber coupled output laser source unit is stationary, only the middle core of the vibrating multi-core fiber can detect the optical signal. When the vibrating multi-core fiber undergoes multi-dimensional displacement due to external vibration, the different vibration directions cause the different cores of the vibrating multi-core fiber to be in the ray direction of the first single-mode fiber, thereby enabling the different cores of the vibrating multi-core fiber to output optical signals. Vibration detection is then performed by measuring the light intensity output by the different cores.

2. The multidimensional vibration sensor based on multi-core optical fiber according to claim 1, characterized in that, The fan-out module includes: a multi-core optical fiber connected to the vibrating multi-core optical fiber, and multiple output ports; The multi-core optical fiber is connected to the other end of the vibrating multi-core optical fiber along its axis to receive the optical signal, and each of the output ports outputs the optical signal to the vibration signal detection module.

3. The multidimensional vibration sensor based on multi-core optical fiber according to claim 1, characterized in that, The vibration signal detection module includes: multiple second single-mode optical fibers, multiple photodetectors, and multiple oscilloscopes; One end of each of the second single-mode optical fibers serves as one end of the vibration signal detection module; The other end of each of the second single-mode optical fibers is connected to one end of each of the photodetectors; wherein, the second single-mode optical fiber corresponds one-to-one with the photodetector. The other end of each photodetector is connected to the input terminal of each oscilloscope, and the photodetector corresponds to the oscilloscope.

4. The multidimensional vibration sensor based on multi-core optical fiber according to claim 2, characterized in that, The number of the plurality of output ports is the same as the number of cores of the vibrating multi-core optical fiber.

5. The multidimensional vibration sensor based on multi-core optical fiber according to claim 3, characterized in that, The number of the plurality of second single-mode optical fibers, the plurality of photodetectors, and the plurality of oscilloscopes are the same as the number of cores of the vibrating multi-core optical fiber.

6. The multidimensional vibration sensor based on multi-core optical fiber according to claim 1, characterized in that, The cores of the vibrating multi-core optical fiber have the same core diameter as the first single-mode optical fiber.

7. The multidimensional vibration sensor based on multi-core optical fiber according to claim 1, characterized in that, The vibrating multi-core optical fiber is a weakly coupled optical fiber.

8. The multidimensional vibration sensor based on multi-core optical fiber according to claim 1, characterized in that, The spacing between the cores of the vibrating multi-core optical fiber is smaller than the core diameter of each core.

9. A vibration detection method based on a multi-core optical fiber multidimensional vibration sensor, characterized in that, The method uses a multi-core optical fiber-based multidimensional vibration sensor as described in any one of claims 1-8 to perform vibration detection; the method includes: The vibrating multi-core optical fiber receives the optical signal emitted by the light source module in a static or vibrating state; The vibrating multi-core optical fiber transmits the optical signal to the fan-out module through its respective cores. The fan-out module outputs the optical signal to the vibration signal detection module according to the corresponding optical fiber from which the optical signal is acquired, so that the vibration signal detection module can output the light intensity of the optical signal of each fiber core.

Images