Optical fiber pressure detection sensor based on visible light

Abstract

The utility model relates to an optical fiber pressure detection sensor based on visible light, which belongs to the field of pressure detection equipment and comprises an upper flat plate and a lower flat plate. The plurality of springs are connected between the upper flat plate and the lower flat plate; according to the technical scheme, external pressure can be converted into pressure of the optical fiber coil, the problem that a sheet in an existing optical fiber pressure sensor is prone to plastic deformation can be solved, interference patterns of optical signals are changed by extruding the optical fiber coil, and the optical fiber pressure sensor can be used for detecting the interference of the optical signals. The interference pattern change and the pressure are associated by using the existing deep learning model, so that the pressure can be obtained, and the purpose of pressure detection is achieved.

Description

Technical Field

[0001] The utility model relates to the field of pressure detection equipment, in particular to an optical fiber pressure detection sensor based on visible light. Background Art

[0002] Pressure detection plays a vital role in the production process of enterprises, especially in terms of accurate pressure measurement and improving pressure detection accuracy. It has become an important symbol of refined production and even affects the benefits of enterprises. Fiber Bragg grating pressure sensors have the advantages of high precision, high reliability and strong anti-electromagnetic interference ability, and can be widely used in real-time pressure monitoring. However, fiber Bragg grating pressure sensors mainly use grating demodulators to demodulate the central wavelength of fiber Bragg gratings. However, grating demodulators are relatively expensive, which makes the entire fiber Bragg grating pressure detection cost relatively high. There is also a fiber optic FP pressure sensor whose principle is as follows Figure 2 As shown, an elastic alloy sheet serves as a cross-section of the FP cavity, with its polished surface serving as a reflective surface. The optical fiber is aligned with the center of the elastic alloy surface, and the fiber end directly serves as another reflective surface. Appropriate reflectance ratios are selected for both end surfaces, thus forming an FP cavity between the fiber end and the alloy sheet. When pressure acts on the alloy sheet, elastic deformation occurs. This deformation of the alloy sheet causes the FP cavity length to change, and this change causes the interference pattern of the optical signal to change. By detecting this change, the applied pressure can be calculated. However, the above-mentioned film will undergo plastic deformation after repeated stress. Continued use of the deformed film affects the accuracy of the cavity length change, thereby affecting the accuracy of pressure detection. Utility Model Content

[0003] The film of an existing optical fiber pressure sensor is prone to plastic deformation during long-term use, which affects the accuracy of cavity length changes during subsequent use, thereby affecting the accuracy of pressure detection. At least one aspect or purpose of the present application can solve the above problem. Specifically, a new device for optical fiber pressure detection sensor based on visible light is designed. The specific technical solution adopted is as follows:

[0004] Fiber optic pressure detection sensor based on visible light, including:

[0005] Upper and lower plates;

[0006] A plurality of springs are connected between the upper plate and the lower plate;

[0007] The optical fiber coil is vertically arranged between the upper plate and the lower plate, and is formed by winding a step-index single-mode optical fiber.

[0008] Preferably, the upper plate and the lower plate are square plates of equal size, and the center of the optical fiber coil is located on the center line of the upper plate and the lower plate.

[0009] Preferably, the optical fiber coil is fixed by buckles provided on the upper plate and the lower plate.

[0010] Preferably, four springs are provided, the four springs are evenly distributed between the upper plate and the lower plate, and the four springs are located on the periphery of the optical fiber coil.

[0011] Preferably, at least two guide columns are vertically provided between the upper plate and the lower plate, and the at least two guide columns are symmetrically arranged relative to the central connecting line of the upper plate and the lower plate. The lower end of each guide column is fixed to the lower plate, and each guide column has a guide groove along its length direction, and the upper plate is slidably arranged in the guide groove.

[0012] Preferably, the outer diameter of the optical fiber in the optical fiber coil is 3 mm, and the optical fiber coil is wound twice with a winding diameter of 10 cm.

[0013] Preferably, a force-bearing block is provided at the center of the upper surface of the upper plate, and the force-bearing block is arranged higher than the upper surface of the upper plate.

[0014] Through the above-mentioned technical solution, the present invention can not only convert external pressure into optical fiber coil pressure, but also avoid the problem that the current optical fiber pressure sensor sheet is prone to plastic deformation. By squeezing the optical fiber coil, the interference pattern of the light signal changes. By establishing a correlation between the interference pattern change and the pressure using the existing deep learning model, the pressure size can be obtained, thereby achieving the purpose of pressure detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] Figure 2 It is a structural diagram of the prior art.

[0017] In the figure, 1. upper plate, 2. lower plate, 3. spring, 4. guide column, 5. guide groove, 6. buckle, 7. optical fiber coil, 8. force block. DETAILED DESCRIPTION

[0018] In order to clearly illustrate the technical features of this solution, the present invention is described in detail below through specific implementation methods and in conjunction with the accompanying drawings.

[0019] In addition, in the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0020] like Figure 1 As shown, the optical fiber pressure detection sensor based on visible light includes an upper plate 1 and a lower plate 2, which are spaced apart from each other. A plurality of springs 3 are provided between the upper plate 1 and the lower plate 2. The presence of the springs 3 allows the upper plate 1 and the lower plate 2 to move relative to each other up and down, thereby changing the distance between the upper plate 1 and the lower plate 2. The spring coefficient of the spring 3 can be selected as needed, or springs 3 with different spring coefficients can be replaced during use to achieve detection ranges of different sensitivities and different pressures.

[0021] At the same time, an optical fiber coil 7 is provided between the upper plate 1 and the lower plate 2. The optical fiber coil 7 is arranged in a vertical plane. The upper plate 1 is subjected to force to squeeze the optical fiber coil 7. The optical fiber coil is wound with a step-index single-mode optical fiber. When visible light with a wavelength of 633nm is injected, the step-index single-mode optical fiber becomes a multi-mode optical fiber. The mode field distribution between the high-order modes therein is different, and their group velocities are also different. Interference occurs between different modes, and thus an interference pattern is generated. When the optical fiber coil 7 is squeezed, the interference pattern of the optical signal changes. By establishing a correlation between the change in the interference pattern and the pressure using an existing deep learning model, the pressure magnitude can be obtained.

[0022] The existing deep learning model can adopt the YOLO11 model and improve and optimize it. When specifically detecting pressure, optical elements can be used to process visible light of a specific wavelength first, and then the spatial light is coupled to this optical fiber. The optical fiber is then coupled to the spatial light and transmitted to the imaging element to form a light spot image. By presenting a real-time picture of the light spot on a computer, and finally sending the real-time picture into the trained YOLO11 deep learning model to identify the light spot picture, the trained deep learning model establishes a correlation between the light spot image and the extrusion pressure, and the extrusion pressure exerted on the optical fiber coil 7 at the corresponding moment can be obtained.

[0023] The light of the above-mentioned specific wavelength is 633nm light. At this wavelength, the step-index single-mode optical fiber becomes a multimode optical fiber. The light is transmitted in the optical fiber in a multimode form. After the optical fiber coil 7 is squeezed, interference occurs between different modes, which produces an interference pattern. The different squeezing forces cause the interference pattern to change. Therefore, the squeezing force can be obtained from the light spot pattern, thereby achieving the purpose of pressure detection.

[0024] The light is processed using an existing method, using a laser emitting a specific wavelength to generate a 633nm light source. The light source can pass through a half-wave plate, a polarization beam splitter, a reflector, etc. into a collimator to couple the spatial light into the optical fiber. After the optical fiber is wrapped twice, the collimator couples the optical fiber into spatial light and enters an imaging element, such as a CMOS camera or CCD camera, to obtain real-time changes in the light spot pattern, which is finally displayed on a computer.

[0025] Furthermore, the upper plate 1 and the lower plate 2 are square plates of equal size, and the center of the optical fiber coil 7 is located on the center line of the upper plate 1 and the lower plate 2. The square plates have good symmetry and a compact structure, and the distance from the center to the four corners is equal, so they have good stability when subjected to force.

[0026] Furthermore, the optical fiber coil 7 is fixed by a buckle 6 provided on the upper plate 1 and the lower plate 2. The buckle 6 facilitates the disassembly and replacement of the optical fiber coil 7 to facilitate the adjustment of the number of winding turns or the winding radius.

[0027] Furthermore, specifically, in order to improve the movement stability of the upper plate 1, four springs 3 are provided, and the four springs 3 are evenly distributed between the upper plate 1 and the lower plate 2, and the four springs 3 are located on the periphery of the optical fiber coil 7. In this way, the springs 3 can achieve telescopic deformation without interfering with the deformation of the optical fiber coil 7 due to compression.

[0028] Furthermore, in order to prevent the upper plate 1 from shifting in the horizontal direction while moving up and down, at least two guide posts 4 are vertically provided between the upper plate 1 and the lower plate 2. In this embodiment, four guide posts 4 are provided to match the shapes of the upper plate 1 and the lower plate 2. The four guide posts 4 are correspondingly located at the four corners of the upper plate 1 and the lower plate 2. The lower end of each guide post 4 is fixed on the lower plate 2. Each guide post 4 has a guide groove 5 along its length. The upper plate 1 is slidably provided in the guide groove 5 and can slide along the guide groove 5.

[0029] Furthermore, the outer diameter of the optical fiber in the above-mentioned optical fiber coil 7 is 3 mm, the winding diameter is 10 cm, and the optical fiber coil 7 is wound 2 turns, so that the light spot diagram presents two light spots. The two light spots can meet the reference requirements and avoid the existence of accidental factors that cause interference image changes. At the same time, it will not significantly increase the recognition amount of the deep learning model.

[0030] Furthermore, a force block 8 is provided at the center of the upper surface of the upper plate 1. The force block 8 is arranged higher than the upper surface of the upper plate 1. When the upper plate 1 is subjected to pressure, the force block 8 is first contacted and squeezed, which can ensure that the force is pressed down from the center of the upper plate 1, ensuring that the upper plate 1 moves downward horizontally, and avoiding the upper plate 1 from tilting sideways.

[0031] The above specific implementation methods cannot be used as a limitation on the protection scope of the present utility model. For those skilled in the art, any replacement, improvement or transformation made to the implementation methods of the present utility model falls within the protection scope of the present utility model.

[0032] Anything not described in detail in the present invention is well known to those skilled in the art.

Claims

1. A fiber optic pressure detection sensor based on visible light, characterized in that: include: Upper and lower plates; a plurality of springs connected between the upper plate and the lower plate; The optical fiber coil is vertically arranged between the upper plate and the lower plate, and the optical fiber coil is formed by winding a step-index single-mode optical fiber.

2. The optical fiber pressure detection sensor based on visible light according to claim 1, characterized in that: The upper plate and the lower plate are square plates of equal size, and the center of the optical fiber coil is on a center line between the upper plate and the lower plate.

3. The optical fiber pressure detection sensor based on visible light according to claim 1 or 2, characterized in that: The optical fiber coil is fixed by buckles arranged on the upper plate and the lower plate.

4. The optical fiber pressure detection sensor based on visible light according to claim 2, characterized in that: Four springs are provided, and the four springs are evenly distributed between the upper plate and the lower plate, and the four springs are located on the periphery of the optical fiber coil.

5. The optical fiber pressure detection sensor based on visible light according to claim 1, characterized in that: At least two guide posts are vertically provided between the upper plate and the lower plate, and the at least two guide posts are symmetrically arranged relative to the central connecting line of the upper plate and the lower plate. The lower end of each guide post is fixed to the lower plate, and each guide post has a guide groove along its length direction, and the upper plate is slidably arranged in the guide groove.

6. The optical fiber pressure detection sensor based on visible light according to claim 1, characterized in that: The outer diameter of the optical fiber in the optical fiber coil is 3 mm, and the optical fiber is wound twice with a winding diameter of 10 cm.

7. The optical fiber pressure detection sensor based on visible light according to claim 1, characterized in that: A force-bearing block is provided at the center of the upper surface of the upper plate, and the force-bearing block is arranged higher than the upper surface of the upper plate.

Images