High-precision fiber grating soil pressure sensor

Abstract

The utility model provides a high-precision fiber bragg grating soil pressure sensor, which comprises a bottom film, an upper cover is arranged on the bottom film, an adhesive terminal mounting part is arranged on the inner bottom surface of the bottom film, the bottom film is connected with an adhesive terminal through the adhesive terminal mounting part, a connecting pipe fixing part is arranged on the upper cover, and the connecting pipe fixing part is connected with the adhesive terminal through the connecting pipe fixing part. The upper cover is installed and connected with one end of the connecting pipe through the connecting pipe fixing part, an adjusting terminal is arranged in the connecting pipe, one end of a high-strength strain optical fiber is pasted on the pasting terminal, and the other end of the high-strength strain optical fiber is pasted on the adjusting terminal; the device is simple in structure and convenient to mount, can perform high-precision monitoring on the soil pressure, and improves the measurement precision and stability.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of optical fiber sensor, concretely relates to a high accuracy fiber grating soil pressure sensor. BACKGROUND

[0002] Since the fiber grating was invented, it has been widely used in the field of optical fiber sensing. Due to the advantages of fiber grating sensor such as anti-electromagnetic interference, corrosion resistance, electrical insulation, high sensitivity, low cost, and good compatibility with ordinary optical fiber, it has attracted more and more attention. Since the resonant wavelength of fiber grating is sensitive to the changes of stress and temperature, it is mainly used for measuring temperature, stress and strain.

[0003] The fiber grating soil pressure gauge is a soil pressure measuring device based on fiber grating technology, which has received widespread attention and application in the fields of civil engineering, geological exploration and environmental monitoring in recent years. The fiber grating soil pressure gauge utilizes the sensitive characteristics of fiber grating to strain, and obtains the change information of soil pressure by measuring the change of fiber grating reflection wavelength. As a new soil pressure measuring technology, fiber grating soil pressure gauge has broad development prospects and application potential. Through continuous technological innovation and application promotion, fiber grating soil pressure gauge is expected to play a more important role in future engineering monitoring and provide strong technical support for engineering safety and environmental protection

[0004] However, the application of fiber grating technology in soil pressure measurement is not a simple technology transplantation. How to ensure the stable working state of fiber grating in the complex and changeable soil environment, how to effectively combine fiber grating with soil pressure sensing structure, and how to realize high-precision, reliable and easy-to-install soil pressure sensor are the technical problems to be solved at present.

[0005] The existing fiber grating soil pressure sensor often has problems such as complex structure, inconvenient installation, insufficient precision or poor stability in design. For example, some sensors are prone to uneven force or damage in the grating area due to improper fixing method of fiber grating, which affects the measurement accuracy; some other sensors are prone to be affected by environmental factors during long-term use due to unreasonable structure design, resulting in decline of measurement performance.

[0006] The disclosure of the above background technology content is only used to assist understanding of the utility model concept and technical scheme of the utility model, which does not necessarily belong to the prior art of the present patent application, nor does it necessarily provide technical teaching; in the absence of explicit evidence that the above content has been disclosed before the filing date of the present patent application, the above background technology should not be used to evaluate the novelty and inventiveness of the present application. UTILITY MODEL CONTENT

[0007] In order to solve the technical problems of the existing fiber grating soil pressure sensor, such as complex structure, inconvenient installation, insufficient precision or poor stability, the utility model provides a high-precision fiber grating soil pressure sensor, which has simple structure, convenient installation, can monitor the soil pressure with high precision, and improves the precision and stability of measurement.

[0008] In order to achieve the above purpose, the technical scheme of the utility model is as follows:

[0009] The utility model provides a kind of high-precision fiber grating soil pressure sensor, comprising: bottom film, upper cover is installed on the bottom film, the inner bottom surface of the bottom film is provided with adhesive terminal mounting part, the bottom film is connected with adhesive terminal by the adhesive terminal mounting part, the upper cover is provided with connecting pipe fixed part, the upper cover is connected with the one end of connecting pipe by the connecting pipe fixed part, adjusting terminal is equipped in the connecting pipe, one end of high-strength strain fiber is pasted on the adhesive terminal, another end of high-strength strain fiber is pasted on the adjusting terminal.

[0010] The utility model provides a kind of high-precision fiber grating soil pressure sensor, which has simple structure, convenient installation, can monitor the soil pressure with high precision, and improves the precision and stability of measurement.

[0011] As preferred technical scheme, the adjusting terminal is provided with adjusting nut, the adjusting terminal has threaded portion extending along its axial direction, the adjusting nut and the threaded portion of the adjusting terminal are matched with each other, the adjusting nut can be moved along the axial direction of the adjusting terminal by rotating the adjusting nut, and the position of the adjusting terminal relative to a fixed point is adjusted.

[0012] As preferred technical scheme, another end of the high-strength strain fiber is associated with adjusting nut, the tension state of the high-strength strain fiber can be adjusted by rotating the adjusting nut, so that the pre-tension wavelength is changed.

[0013] As preferred technical scheme, the other end of the connecting pipe is connected with one end of adjusting terminal protection pipe, the other end of the adjusting terminal protection pipe is connected with pressure wire terminal.

[0014] As preferred technical scheme, the pressure wire terminal is provided with lead outer sheath outside.

[0015] As preferred technical scheme, the high-strength strain grating is high-strength femtosecond grating, the wavelength change is greater than or equal to 30nm, and the wavelength change of the high-strength fiber grating is linearly related to the amount of change of soil pressure.

[0016] As preferred technical scheme, the connecting pipe is of hollow structure.

[0017] As a preferred technical solution, the connecting pipe fixing part is arranged at the center position of the upper cover, and the upper cover is further provided with an upper cover tightening hole, which is arranged on both sides of the connecting pipe fixing part.

[0018] As a preferred technical solution, the bottom film comprises: a stress bottom film, a bottom film side wall is arranged at the edge of the stress bottom film in a circumferential direction to form a bottom film, and a bottom film mounting thread is arranged on the bottom film side wall, and the bottom film is mounted and connected with the upper cover through the mounting thread.

[0019] As a preferred technical solution, the sticking terminal mounting part is arranged at the center position of the stress bottom film, and the sticking terminal mounting part is in an integrated molding structure with the stress bottom film.

[0020] The high-precision fiber grating soil pressure sensor has the following beneficial effects:

[0021] 1) The structure is simple, convenient to install, can monitor the soil pressure with high precision, improve the measurement accuracy, and ensure the stability of the measurement;

[0022] 2) The sensor adopts modular design, and the bottom film, the upper cover, the connecting pipe and the like can be independently installed, which is convenient for production and maintenance; this design not only simplifies the structure of the sensor, but also makes the installation process more convenient and fast; the sticking terminal mounting part, the connecting pipe fixing part and the like are designed with standardized interfaces, which ensures the accurate cooperation and stable connection between the parts; this helps to reduce the error in the installation process and improve the installation efficiency; the design of the adjusting terminal makes the high-strength strain optical fiber convenient to tension and adjust, so as to adapt to different measurement requirements and working environments;

[0023] In use, first, the high-precision fiber grating soil pressure sensor is installed into the measured soil; when the soil has pressure change, the soil will extrude the bottom film, so that the inside of the bottom film is protruded, and then the sticking terminal is lifted, the high-strength strain optical fiber is compressed, the wavelength change of the light inside the high-strength strain optical fiber is affected, and finally the soil pressure change is reflected, a large amount of high-precision data is provided for subsequent soil pressure monitoring, the soil pressure can be monitored with high precision, the measurement accuracy is improved, and the stability of the measurement is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The utility model provides a kind of high-precision fiber grating soil pressure sensor structure schematic view for the utility model;

[0025] Figure 2 The utility model provides a kind of high-precision fiber grating soil pressure sensor structure schematic view for the utility model;

[0026] Figure 3The utility model provides a kind of high-precision fiber grating soil pressure sensor upper cover structure diagram for the utility model provides a kind of high-precision fiber grating soil pressure sensor upper cover structure diagram.

[0027] Wherein, 1-bottom film;2-upper cover;21-upper cover tightening hole;22-connection pipe fixed part;3-paste terminal;4-high strength strain fiber;5-connection pipe;6-adjusting nut;7-adjusting terminal protection pipe;8-wire pressing terminal;9-lead outer sheath;10-adjusting terminal;11-force bottom film;12-paste terminal mounting portion;13-bottom film mounting thread. DETAILED DESCRIPTION

[0028] The preferred embodiment of the utility model is described in detail below with reference to the drawings.

[0029] As Figures 1-3 Indicated, the utility model provides a kind of high-precision fiber grating soil pressure sensor, comprising: bottom film 1, install upper cover 2 on the bottom film 1, the inner bottom surface of bottom film 1 is provided with paste terminal mounting portion 12, bottom film 1 is installed and connected with paste terminal 3 by paste terminal mounting portion 12, upper cover 2 is provided with connection pipe fixed part 22, upper cover 2 is installed and connected with one end of connection pipe 5 by connection pipe fixed part 22, adjusting terminal 10 is equipped in connection pipe 5, one end of high strength strain fiber 4 is pasted on paste terminal 3, the other end of high strength strain fiber 4 is pasted on adjusting terminal 10.

[0030] The utility model provides a kind of high-precision fiber grating soil pressure sensor, it is simple in structure, easy to install, can carry out high-precision monitoring to soil pressure, improve the precision of measurement, guarantee the stability of measurement.

[0031] Preferably, as Figure 1 Indicated, adjusting nut 6 is equipped on adjusting terminal 10, adjusting terminal 10 has the threaded portion extending along its axial direction, adjusting nut 6 and the threaded portion of adjusting terminal 10 are mutually matched, by rotating adjusting nut 6 can move along the axial direction of adjusting terminal 10, for adjusting the position of adjusting terminal 10 relative to a fixed point;Adjusting nut 6 and the threaded portion of adjusting terminal 10 are mutually matched, so that by rotating adjusting nut 6 can move along the axial direction of adjusting terminal 10;This design allows the position of adjusting terminal relative to a fixed point to be accurately adjusted;In the working process of sensor, it can be necessary to adjust the grid area of high strength strain fiber 4 according to actual soil pressure situation or measurement demand;The existence of adjusting nut 6 makes this fine adjustment possible, so as to ensure that sensor can always be in the best working state.

[0032] Preferably, as Figure 1As shown, the other end of the high-strength strain fiber 4 is associated with the adjusting nut 6, and the tension state of the high-strength strain fiber 4 can be adjusted by rotating the adjusting nut 6, so as to change the pre-tension wavelength; the tension state of the high-strength strain fiber 4 can be finely adjusted by rotating the adjusting nut 6; this adjustment mechanism ensures that the fiber can maintain the best response state when subjected to soil pressure, thereby improving the accuracy of the measurement; the tension state of the high-strength strain fiber 4 directly affects its sensitivity to strain and the stability of the measurement, so accurate adjustment by adjusting the adjusting nut 6 is crucial; when the high-strength strain fiber 4 is subjected to pre-tension, the grating region will produce a certain amount of wavelength shift, which is called the pre-tension wavelength; by adjusting the tension state of the fiber by rotating the adjusting nut 6, the pre-tension wavelength can be changed, thereby optimizing the measurement accuracy of the sensor; adjustment of the pre-tension wavelength helps to reduce measurement errors and improve the response sensitivity of the sensor to changes in soil pressure.

[0033] Preferably, as shown in Figure 1 As shown, the other end of the connecting pipe 5 is connected to one end of the adjusting terminal protection pipe 7, and the other end of the adjusting terminal protection pipe 7 is connected to the wire pressing terminal 8; by designing the connecting pipe 5 and the adjusting terminal protection pipe 7, the signal loss of the fiber during transmission can be reduced, thereby ensuring that the sensor can accurately measure the soil pressure; the design of the connecting pipe 5 and the adjusting terminal protection pipe 7 can provide an additional shielding layer for the fiber, reducing the influence of external electromagnetic interference on the sensor, thereby improving the stability and accuracy of the measurement; the design of the connecting pipe 5 and the adjusting terminal protection pipe 7 makes the installation process of the sensor more convenient.

[0034] Preferably, as shown in Figure 1 As shown, the wire pressing terminal 8 is provided with an outer lead sheath 9 for protecting the lead; the design of the lead sheath 9 makes the installation of the lead more convenient; the operator can easily pass the lead through the lead sheath 9 and connect it to the wire pressing terminal 8 without complicated operations.

[0035] Preferably, as shown in Figure 1 As shown, the high-strength strain grating 4 is a high-strength femtosecond grating with a wavelength change of ≥30 nm; the wavelength change of the high-strength fiber grating 4 is linearly related to the amount of change in soil pressure, and the wavelength change range of the high-strength femtosecond grating is large (≥30 nm), which means that under the same change in soil pressure, the wavelength shift of the grating is larger, thereby improving the sensitivity of the sensor; in combination with the linear relationship between the wavelength change of the high-strength fiber grating 4 and the amount of change in soil pressure, the sensor can ensure extremely high resolution precision (up to 0.3 per ten thousand) when monitoring soil pressure, further improving the accuracy of the measurement and ensuring the stability of the measurement.

[0036] Preferably, as shown in Figure 1As shown, the connecting pipe 5 is a hollow structure; the hollow structure of the connecting pipe 5 and the design of the adjusting terminal 10 make the installation of the fiber grating more convenient; the operator can easily pass the fiber grating through the connecting pipe 5 and paste it on the adjusting terminal 10 without complicated operation; during the use of the sensor, if maintenance or replacement of the fiber grating is required, the hollow structure of the connecting pipe 5 and the adjusting terminal 10 can be easily disassembled and reinstalled; this helps to reduce the difficulty and cost of maintenance, improve the reliability and service life of the sensor.

[0037] Preferably, as Figure 3 As shown, the connecting pipe fixing part 22 is arranged at the center of the upper cover 2, and the upper cover 2 is also provided with an upper cover tightening hole 21, which is arranged on both sides of the connecting pipe fixing part 22; the upper cover tightening hole 21 can allow the assembler to tighten the upper cover to ensure the sealing effect.

[0038] Preferably, as Figure 2 As shown, the bottom film 1 includes: a stress bottom film 11, which is circumferentially provided with a bottom film side wall to form a bottom film 1, and the bottom film side wall is provided with a bottom film mounting thread 13 on the top, and the bottom film 1 is installed and connected with the upper cover 2 through the mounting thread 13; the design of the stress bottom film 11 makes the sensor better withstand external pressure; when the soil body exerts pressure on the sensor, the stress bottom film 11 can disperse the pressure to the entire area of the bottom film 1, thereby reducing the influence of local pressure on the sensor; by enhancing the stress performance, the bottom film 1 can better transmit the soil pressure to the high-strength fiber grating 4; this helps to ensure that the high-strength fiber grating 4 can accurately respond to changes in soil pressure, thereby improving the measurement accuracy and reliability of the sensor.

[0039] Preferably, as Figure 2 As shown, the sticking terminal mounting part 12 is arranged at the center of the stress bottom film 11, and the sticking terminal mounting part 12 and the stress bottom film 11 are an integral molding structure; it ensures accurate positioning and installation of the sticking terminal position, and the integral molding structure of the sticking terminal mounting part 12 and the stress bottom film 11 helps to optimize the stress distribution inside the sensor; when the soil body exerts pressure on the sensor, the stress can be more evenly distributed on the stress bottom film 11 and the sticking terminal mounting part 12, thereby ensuring that the fiber grating can accurately respond to changes in soil pressure; the integrated design reduces measurement errors caused by loose or damaged connecting parts; this helps to improve the measurement accuracy and stability of the sensor, so that it can more accurately reflect the changes in soil pressure.

[0040] The external lead is an armored optical cable, the lead outer sheath 9 adopts a PVC rubber sleeve, the adjusting terminal 10, the bottom film 1, the upper cover 2, the pasting terminal 3 and the adjusting nut 6 are made of 316L stainless steel, the wire pressing terminal 8, the connecting pipe 5 and the adjusting terminal protection pipe 7 are made of 304 stainless steel; the rust-proof and waterproof material is used to overcome the problems of condensation and electromagnetic interference in the sensor in the humid air, greatly prolong the service life of the sensor, and improve the reliability of the sensor.

[0041] The utility model discloses a high-precision fiber grating soil pressure sensor, when using, first high-precision fiber grating soil pressure sensor is installed to the soil body of being measured, when the soil body has pressure change, the soil body will extrude bottom film 1, make bottom film 1 inside protrude, and then make pasting terminal 3 lift, compress high-strength fiber grating 4, influence high-strength fiber grating 4 inside light wavelength change, finally reflect the soil body pressure change, provide a large amount of high-precision data for subsequent soil body pressure monitoring, wherein the wavelength change of high-strength fiber grating 4 and soil body pressure change amount are linear relation, high-strength strain grating 4 preferably high-strength femtosecond grating, and its wavelength change is up to 30nm, can ensure that the sensor has very high resolution accuracy (up to 0.3 ten thousandth) when monitoring soil body pressure, further improve the accuracy of measurement, guarantee the stability of measurement.

[0042] The utility model discloses a whole simple structure, convenient transportation, installation is quick, can carry out high-precision monitoring to soil body pressure, through the compression and stretch of high-strength strain grating 4 reflect the outside measured pressure change, this high-strength strain grating 4 adopts high-strength femtosecond grating, and its wavelength change is up to 30nm, and it is sensitive, and the precision is high, further solve the low accuracy of existing sensor, the problem of inaccurate measurement, simultaneously, high-precision fiber grating soil pressure sensor adopts the installation of the accessory of rustproof waterproof material, overcomes the problem of condensation and electromagnetic interference in the sensor in the humid air, greatly prolongs the service life of the sensor, and improves the reliability of the sensor.

[0043] It can be understood that the utility model is described through some embodiments, and the person skilled in the art knows that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the utility model. In addition, under the guidance of the utility model, these features and embodiments can be modified to adapt to specific conditions and materials without departing from the spirit and scope of the utility model. Therefore, the utility model is not limited by the specific embodiments disclosed herein, and all the embodiments falling within the scope of the claims of the application belong to the scope of protection of the utility model.

Claims

1. A high-precision fiber grating soil pressure sensor, characterized in that, The application relates to a high-strength strain fiber tensioning device, which comprises a bottom film, a top cover mounted on the bottom film, an inner bottom surface of the bottom film provided with a terminal mounting part, the bottom film being mounted and connected with the terminal mounting part through the terminal mounting part, the top cover being provided with a connecting pipe fixing part, the top cover being mounted and connected with one end of the connecting pipe through the connecting pipe fixing part, the connecting pipe being provided with an adjusting terminal, one end of a high-strength strain fiber being pasted on the terminal, and the other end of the high-strength strain fiber being pasted on the adjusting terminal.

2. The high-precision fiber grating soil pressure sensor according to claim 1, characterized in that, The adjusting terminal is provided with an adjusting nut, the adjusting terminal has a threaded part extending along the axial direction, the adjusting nut is matched with the threaded part of the adjusting terminal, the adjusting nut can be moved along the axial direction of the adjusting terminal by rotating the adjusting nut, and the position of the adjusting terminal relative to a fixed point is adjusted.

3. The high-precision fiber grating soil pressure sensor according to claim 1, characterized in that, The other end of the high-strength strain fiber is associated with the adjusting nut, the tensioning state of the high-strength strain fiber can be adjusted by rotating the adjusting nut, so that the pre-tensioning wavelength is changed.

4. The high-precision fiber grating soil pressure sensor according to claim 1, characterized in that, The other end of the connecting pipe is connected with one end of an adjusting terminal protection pipe, and the other end of the adjusting terminal protection pipe is connected with a wire pressing terminal.

5. The high-precision fiber Bragg grating soil pressure sensor according to claim 4, characterized in that, The wire pressing terminal is externally provided with a lead sheath.

6. The high precision fiber Bragg grating soil pressure sensor according to claim 1, wherein, The high-strength strain fiber is a high-strength femtosecond grating, the wavelength change of the high-strength strain fiber is greater than or equal to 30 nm, and the wavelength change of the high-strength strain fiber is linearly related to the change amount of the soil pressure.

7. The high precision fiber grating soil pressure sensor according to claim 1, characterized in that, The connecting pipe is a hollow structure.

8. The high precision fiber Bragg grating soil pressure sensor according to claim 1, wherein, The connecting pipe fixing part is arranged at the central position of the top cover, the top cover is further provided with a top cover tightening hole, and the top cover tightening hole is correspondingly arranged on the two sides of the connecting pipe fixing part.

9. The high precision fiber Bragg grating soil pressure sensor according to claim 1, wherein, The bottom film comprises a stress bottom film, a bottom film side wall is circumferentially arranged at the edge of the stress bottom film to form a bottom film, a bottom film mounting thread is arranged on the bottom film side wall, and the bottom film is mounted and connected with the top cover through the mounting thread.

10. The high precision fiber Bragg grating soil pressure sensor according to claim 9, wherein, The terminal mounting part is arranged at the central position of the stress bottom film, and the terminal mounting part and the stress bottom film are an integral forming structure.

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