A vector flow velocity real-time monitoring system based on FBG optical fiber sensor, a preparation method and a use method

Abstract

The application discloses a kind of based on FBG optical fiber sensor's vector flow rate real-time monitoring system, preparation method and use method, system includes FBG optical fiber, six cube pedestals, FBG demodulator, optical fiber coupler, vector flow rate conversion module;FBG optical fiber stress expansion film is embedded in any five surfaces of six cube pedestals, stress expansion film is fixed and drives FBG optical fiber to occur deformation;FBG optical fiber of six cube any five surfaces, constitute three-dimensional vector coordinate surface;Optical fiber coupler is used to converge the FBG optical fiber of five surfaces of six cube pedestals into a bundle, realizes optical coupling;FBG demodulator is used to demodulate the optical fiber after optical coupling of the optical fiber coupler, measures the center wavelength of FBG optical fiber;Vector flow rate conversion module is used to store and process the center wavelength change information of FBG optical fiber measured by the FBG demodulator, and is converted into vector flow rate.The device can detect vector flow rate, has small volume, good stability, long service life, high sensitivity.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic sensing technology, and particularly relates to a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor, its preparation method, and its usage method. 。 Background Technology

[0002] Underwater vector velocity detection is a key measurement technology used in hydrology, military, and other fields, typically to understand the direction and velocity of water flow within a body of water. In hydrology, analyzing vector velocity helps understand the movement patterns of water bodies, such as velocity variations in different areas of rivers, lakes, or oceans. Furthermore, processing, analyzing, and interpreting the collected vector velocity data allows for a better understanding and prediction of water movement characteristics. In the military field, this measurement task plays a crucial role, such as in submarine navigation and collision avoidance, underwater sonar detection and target identification, underwater channel management and traffic control, and performance evaluation of underwater weapon systems. In general, accurate detection of underwater vector velocity is essential for understanding the dynamic processes of water movement. Currently, underwater velocity detection typically utilizes various techniques, including acoustic measurement, laser Doppler measurement, and electromagnetic induction lamps. However, current velocity detection methods cannot achieve point-to-point vector velocity monitoring and are costly, have slow response times, and cannot operate for extended periods.

[0003] Fiber optic sensors have attracted widespread attention from researchers due to their advantages such as miniaturization, low cost, resistance to electromagnetic interference, and high sensitivity. Summary of the Invention

[0004] To solve the above problems, the technical solution adopted by the present invention is: a real-time vector velocity monitoring system based on FBG fiber optic sensor, including FBG fiber, a six-sided three-dimensional base, an FBG demodulator, a fiber optic coupler, and a vector velocity conversion module;

[0005] The six-sided three-dimensional base is positioned underwater;

[0006] A stress-expanding film of the FBG optical fiber is embedded on any five of the six-sided three-dimensional base. The stress-expanding film is used to fix and drive the FBG optical fiber to deform.

[0007] The six-sided FBG optical fiber with any five sides forms a three-dimensional vector coordinate plane, thereby realizing the detection of vector velocity in the flow field space.

[0008] The fiber optic coupler is used to combine the FBG fibers from the five sides of the six-sided three-dimensional base into a bundle to achieve optical coupling.

[0009] The FBG demodulator is used to demodulate the optical fiber after optical coupling by the optical fiber coupler and measure the center wavelength of the FBG optical fiber.

[0010] The vector velocity conversion module is used to store and process the center wavelength change information of the FBG fiber measured by the FBG demodulator and convert it into a vector velocity.

[0011] Furthermore, the FBG optical fiber is a commercial single-mode optical fiber and a commercial FBG sensing element.

[0012] Furthermore, the FBG optical fiber on the horizontal plane of the six-sided three-dimensional base is perpendicular to the FBG optical fiber on the vertical plane.

[0013] A method for fabricating a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor includes the following steps:

[0014] Step 1: Make a square groove with a thickness of 1mm and a size of 40mm*40mm. Make a circular hole with a diameter of 0.1mm at each end of the groove at a height of 0.5mm.

[0015] Step 2: Take out the AB glue from the Econflex series platinum silicone in a 1:1 ratio, stir it thoroughly, and then remove the air bubbles in a vacuum heating box;

[0016] Step 3: First, suspend the FBG optical fiber in the groove through the circular hole, then pour the mixed adhesive evenly into the groove, and let it stand at 25°C for 3 to 4 hours for silicone curing.

[0017] Step 4: Adhere the cured FBG-embedded stress-expanding film to the five faces of the hollow square base using adhesive, ensuring that the initial tension of each face is the same;

[0018] Step 5: Fusion the five FBG optical fibers to a 1*5 fiber coupler for connection to the FBG demodulator.

[0019] A method for using a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor includes the following steps:

[0020] Step 1: Turn on the FBG demodulator, connect the coupler and the computer, and open the computer monitoring software to obtain the initial multi-channel FBG spectrum;

[0021] Step 2: Place the six-sided three-dimensional base, which has been covered with the stress-expanding film embedded with FBG optical fiber, into the watershed to be measured.

[0022] Step 3: When the flow field around the FBG fiber changes, the changes in the multi-channel FBG spectrum are monitored, and the real-time wavelength changes of each channel are recorded.

[0023] Step 4: Calculate and reconstruct the real-time vector velocity based on the changing wavelength.

[0024] This invention provides a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor, along with its fabrication and usage methods. Based on the aforementioned advantages of fiber optic sensors and combined with flexible materials, this invention leverages the properties of both optical fibers and flexible materials to achieve high-precision and rapid iterative measurements. Its greatest advantage lies in its ability to detect vector flow velocity, thus expanding the application scope of fiber optic sensing technology underwater. To this end, a system is designed that combines FBG optical fibers with flexible materials and analyzes the fiber wavelength using a demodulator. This monitoring system analyzes the vector flow velocity by monitoring changes in the center wavelength of the FBG optical fiber, utilizing the sensitivity of the FBG optical fiber and the resilience and flexibility of the flexible material to achieve high-sensitivity, low-cost, and real-time measurement of vector flow velocity.

[0025] This device has excellent performance characteristics such as the ability to detect vector flow velocity, small size, good stability, long service life, high sensitivity, long-distance transmission capability, and wavelength reusability. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a general schematic diagram of the detection device provided in this application.

[0028] Figure 2 This is a schematic diagram of the detection flow rate along the X-axis direction provided in this application.

[0029] Figure 3 This is a schematic diagram of the detection flow rate along the XY axis provided in this application.

[0030] Figure 4 This is a schematic diagram of the detection flow rate along the XYZ axis provided in this application.

[0031] Reference numerals: 1. Force-bearing extended film, 2. FBG optical fiber, 3. Six-sided three-dimensional base, 4. Fiber optic coupler, 5. FBG demodulator, 6. Computer. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] like Figure 1 As shown, the present invention discloses a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor, including an FBG fiber optic cable 2, a force-bearing extended film 1, a six-sided three-dimensional base 3, an FBG demodulator 5, a computer 6, and a fiber optic coupler 4.

[0035] The six-sided three-dimensional base is positioned underwater;

[0036] The six-sided solid base 3 adopts a square frame or a rectangular frame;

[0037] A stress-bearing expansion film 1 is provided on any five of the six-sided three-dimensional base 3; the stress-bearing expansion film 1 is attached to the frame of the six-sided three-dimensional base 3;

[0038] The force-expanding film is used to fix and drive the FBG to deform, while increasing the sensing area for flow velocity, thereby improving the sensitivity to detect changes in flow velocity. When the flow velocity changes, the film deforms, which in turn causes the FBG to deform.

[0039] The force-expanding film 1 on any five sides of the six-sided three-dimensional base 3 is embedded with FBG optical fibers 2 to sense changes in the water flow velocity and generate deformation; thereby detecting the vector flow velocity in the flow field space; when the flow velocity passes through the sensor, the force-expanding film with FBG optical fibers embedded in five directions on the hollow square base will deform.

[0040] The FBG optical fibers on the five different faces of the six-sided three-dimensional base 3 have different directions. When the flow velocity in different directions flows through the sensor, the vector flow velocity in the flow field space can be synthesized by the wavelength change of the FBG on the force-extended thin film in different directions.

[0041] Among them, the FBG optical fiber 2 on the horizontal plane of the six-sided three-dimensional base 3 is perpendicular to the FBG optical fiber 2 on the vertical plane, forming a three-dimensional vector coordinate plane.

[0042] The fiber coupler 4 is used to combine the five-sided FBG optical fibers into a bundle to achieve optical coupling.

[0043] The FBG demodulator 5 is used to demodulate the optical fiber after optical coupling by the optical fiber coupler 4 and measure the center wavelength of the FBG.

[0044] The vector velocity conversion module is used to store, record, and process the center wavelength change information of the FBG fiber measured by the FBG demodulator 5, and calculate and display the converted vector velocity based on sensor sensitivity.

[0045] The vector velocity conversion module is installed on computer 6;

[0046] The FBG optical fiber is a commercial single-mode optical fiber and a commercial FBG sensing element.

[0047] like Figure 1 As shown in the figure, the manufacturing steps of the vector flow velocity real-time monitoring system based on FBG fiber optic sensor in this embodiment are as follows:

[0048] Step 1: Make a square groove with a thickness of 1mm and a size of 40mm*40mm. Make a circular hole with a diameter of 0.1mm at each end of the groove at a height of 0.5mm.

[0049] Step 2: Take out the AB glue from the Econflex series platinum silicone in a 1:1 ratio, stir it thoroughly, and then remove the air bubbles in a vacuum heating box.

[0050] Step 3: First, suspend the FBG fiber 2 in the groove through the circular hole, then pour the mixed adhesive evenly into the groove, and let it stand at 25°C for 3 to 4 hours for silicone curing.

[0051] Step 4: Adhere the cured stress-expanding film 1 embedded with FBG optical fiber to the five sides of the six-sided three-dimensional base 3 with adhesive, ensuring that the initial tension of each side is the same.

[0052] Step 5: Fusion the five FBG optical fibers 2 to the 1*5 fiber coupler 4 for connection to the FBG demodulator 5.

[0053] In this implementation example, the method for using the real-time vector flow velocity monitoring system based on the FBG fiber optic sensor includes the following specific steps:

[0054] Step 1: Turn on the power of the FBG demodulator 5, connect the fiber optic coupler 4 and the computer 6, and open the computer monitoring software to obtain the initial spectrum of the multi-channel FBG.

[0055] Step 2: Place the six-sided three-dimensional base 3, which has been covered with the force-expanding film 1 embedded with FBG optical fiber 2, into the watershed to be measured.

[0056] Step 3: When the flow field at the location of FBG fiber 2 changes, the changes in the multi-channel FBG spectrum are monitored, and the real-time wavelength changes of each channel are recorded.

[0057] Step 4: Using computer software, calculate and reconstruct the real-time vector velocity based on the changing wavelength calibration parameter.

[0058] like Figure 2 , Figure 3 , Figure 4 As shown in the figure, the experimental results in this implementation case are as follows; Figure 2 The sensor response diagram shows the effect of fluid flowing through the sensor along the X-axis.

[0059] Figure 3 The sensor response diagram shows the effect of fluid flowing through the sensor along the XY axis.

[0060] Figure 4 The sensor response diagram shows the effect of fluid flowing through the sensor along the XYZ axis.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A real-time vector flow velocity monitoring system based on an FBG fiber optic sensor, characterized in that: Includes FBG optical fiber, six-sided three-dimensional base, FBG demodulator, fiber optic coupler, and vector velocity conversion module; The six-sided three-dimensional base adopts a hollow square frame or a rectangular frame; The six-sided three-dimensional base is positioned underwater; A force-bearing expansion film embedded with FBG optical fiber is provided on any five of the six-sided three-dimensional base. The force-bearing expansion film is used to fix and drive the FBG optical fiber to deform. The six-sided FBG optical fiber with any five sides forms a three-dimensional vector coordinate plane, thereby realizing the detection of vector flow velocity in the flow field space. The fiber optic coupler is used to combine the FBG fibers from the five sides of the six-sided three-dimensional base into a bundle to achieve optical coupling. The FBG demodulator is used to demodulate the optical fiber after optical coupling by the optical fiber coupler and measure the center wavelength of the FBG optical fiber. The vector velocity conversion module is used to store and process the center wavelength change information of the FBG fiber measured by the FBG demodulator and convert it into a vector velocity.

2. The real-time vector flow velocity monitoring system based on an FBG fiber optic sensor according to claim 1, characterized in that: The FBG optical fiber is a commercial single-mode optical fiber and a commercial FBG sensing element.

3. The real-time vector flow velocity monitoring system based on an FBG fiber optic sensor according to claim 1, characterized in that: The FBG optical fibers on the horizontal plane of the six-sided three-dimensional base are perpendicular to the FBG optical fibers on the vertical plane.

4. A method for manufacturing a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor as described in any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: Make a square groove with a thickness of 1mm and a size of 40mm*40mm. Make a circular hole with a diameter of 0.1mm at each end of the groove at a height of 0.5mm. Step 2: Take out the AB glue from the Econflex series platinum silicone in a 1:1 ratio, stir it thoroughly, and then remove the air bubbles in a vacuum heating box; Step 3: First, suspend the FBG optical fiber in the groove through the circular hole, then pour the mixed adhesive evenly into the groove, and let it stand at 25°C for 3 to 4 hours for silicone curing. Step 4: Adhere the cured FBG-embedded stress-expanding film to the five faces of the hollow square base using adhesive, ensuring that the initial tension of each face is the same; Step 5: Fusion the five FBG optical fibers to a 1*5 fiber coupler for connection to the FBG demodulator.

5. A method of using a real-time vector flow velocity monitoring system based on an FBG fiber optic sensor according to any one of claims 1 to 4, characterized in that, Includes the following steps: Step 1: Turn on the FBG demodulator, connect the coupler and the computer, and open the computer monitoring software to obtain the initial multi-channel FBG spectrum; Step 2: Place the six-sided three-dimensional base, which has been covered with the stress-expanding film embedded with FBG optical fiber, into the watershed to be measured. Step 3: When the flow field around the FBG fiber changes, the changes in the multi-channel FBG spectrum are monitored, and the real-time wavelength changes of each channel are recorded. Step 4: Calculate and reconstruct the real-time vector velocity based on the changing wavelength.

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