Fiber grating inclinometer
The fiber Bragg grating inclinometer solves the problem of poor accuracy and stability of traditional inclinometers in harsh environments by combining deformation components and temperature compensation components, and achieves high sensitivity and wide angle range inclination measurement, adapting to complex environments.
Patent Information
- Application Number
- CN202422296787.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-20
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-09-20
AI Technical Summary
Traditional inclinometers have poor accuracy and stability in harsh environments, making it difficult to achieve high-precision measurements. They are also easily affected by vibration, dust, and humidity changes.
A fiber Bragg grating inclinometer is used, which combines a deformation component and a temperature compensation component, uses a fiber Bragg grating optical fiber to measure the inclination, and combines a Bragg grating optical fiber demodulator to decode the data and eliminate environmental interference.
It realizes high-sensitivity tilt measurement, expanded angle range, strong environmental adaptability, small measurement error, and wide temperature range.
Smart Images
Figure CN223332377U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of measurement, in particular to a fiber grating inclinometer. Background Art
[0002] In numerous fields, including construction, geological monitoring, and industrial automation, structural stability and safety are key factors in ensuring project success and safe operation. With the continuous expansion and increasing complexity of modern engineering projects, the need for structural monitoring and safety management is becoming increasingly urgent. In the construction sector in particular, the continuous growth in building height and volume, coupled with the increasing complexity of the environments in which they operate (such as geological conditions, climate change, and natural disasters), places higher demands on monitoring building structural stability.
[0003] Inclinometers, as an important monitoring tool, are widely used to measure and monitor the tilt angle of objects and are of great significance for assessing the safety status of structures. However, traditional inclinometers face many challenges in practical application. First, construction sites are harsh environments, often accompanied by adverse factors such as strong vibration, dust, and humidity fluctuations. These factors significantly affect the accuracy and stability of inclinometers, resulting in inaccurate or even invalid measurement data. Second, traditional inclinometers often use a single measurement principle, such as a liquid pendulum or bubble tube. These principles are easily interfered with in complex environments, making it difficult to achieve high-precision measurements. Utility Model Content
[0004] The utility model aims to provide a fiber Bragg grating inclinometer which is not easily affected by the surrounding complex environment and has high sensitivity.
[0005] To achieve the above-mentioned purpose, the utility model provides a fiber grating inclinometer, including a packaging shell, the packaging shell including an outer shell and a sealing end cover installed above the outer shell, a fixed base plate is provided at the bottom of the outer shell, an installation space is formed between the outer shell and the sealing end cover, a deformation component is provided in the installation space, corresponding bolt mounting holes are provided at the four corners of the sealing end cover and the outer shell, and the end cover and the outer shell are fixedly connected by bolts.
[0006] Preferably, a first pressing cylinder and a second pressing cylinder are respectively provided on both sides of the shell.
[0007] Preferably, the deformation assembly includes a weight hammer and a strain piece, the strain piece is arranged above the weight hammer, and the strain piece and the weight hammer are connected through a deformation core.
[0008] Preferably, the deformation component further includes a deformed grating optical fiber, and the deformed grating optical fiber sequentially passes through the first pressing cylinder, the installation space and the second pressing cylinder.
[0009] Preferably, the middle section of the deformed grating optical fiber is bonded to the strain member and the weight hammer respectively.
[0010] Preferably, a temperature compensation zone is provided on the side of the weight hammer, and the temperature compensation zone is provided with a temperature compensation grating optical fiber.
[0011] Preferably, the top end of the temperature-compensated grating optical fiber is connected to the deformed grating optical fiber by fusion splicing.
[0012] Therefore, the fiber Bragg grating inclinometer of the present invention adopting the above structure has the following advantages:
[0013] (1) The sensitivity of the measured inclination data can reach 0.03°;
[0014] (2) The angle measurement range of the inclination angle is increased, from -15° to 15°;
[0015] (3) Improved environmental adaptability, with a temperature range of -30° to 80°;
[0016] (4) This device is not easily affected by the complex surrounding environment and detects the measurement error of the inclination angle.
[0017] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a structural diagram of an embodiment of a fiber Bragg grating inclinometer of the present utility model;
[0019] Figure 2 This is a side sectional view of an embodiment of a fiber Bragg grating inclinometer of the present utility model;
[0020] Figure 3 This is a structural diagram of a deformation assembly of an embodiment of a fiber Bragg grating inclinometer of the present utility model;
[0021] Figure 4 This is a front view of a deformation assembly of an embodiment of a fiber Bragg grating inclinometer of the present utility model;
[0022] Figure 5 This is a top view of a deformation assembly of an embodiment of a fiber Bragg grating inclinometer of the utility model;
[0023] Figure 6 This is a relationship diagram between the inclination angle and strain wavelength measured by a fiber optic inclinometer of the utility model;
[0024] Reference numerals
[0025] 1. Outer shell; 2. Sealing end cover; 3. Deformation component; 31. Weight-bearing hammer; 32. Strain piece; 33. Deformation core; 4. Bolt; 5. Pressing cylinder 1; 6. Pressing cylinder 2; 7. Temperature compensation area; 8. Fixed base plate. DETAILED DESCRIPTION
[0026] The technical solution of the present utility model is further described below through the accompanying drawings and embodiments.
[0027] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the usual meanings understood by persons of ordinary skill in the field to which this utility model belongs. The words "first", "second" and similar terms used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.
[0028] Example
[0029] like Figure 1-5 As shown, the present invention provides a fiber Bragg grating inclinometer, comprising a housing, which includes an outer shell 1 and a sealing end cap 2 mounted above the outer shell 1. A fixed base plate 8 is provided at the bottom of the outer shell 1, and the device is fixed to the object being measured via the fixed base plate 8. A first pressing cylinder 5 and a second pressing cylinder 6 are provided on either side of the outer shell 1. An installation space is formed between the outer shell 1 and the sealing end cap 2, and a deformation assembly 3 is provided in the installation space.
[0030] Corresponding bolt mounting holes are provided at the four corners of the sealing end cover 2 and the housing 1. The sealing end cover 2 and the housing 1 are fixedly connected by bolts 4 to ensure that the interior of the package shell is not invaded by dust and to ensure that the inclinometer can work normally in a humid environment.
[0031] The deformation assembly 3 includes a weight 31 and a strain member 32. The strain member 32 is positioned above the weight 31 and is connected to the weight 31 via a deformation core 33. The deformation assembly 3 also includes a deformable grating fiber, which sequentially passes through the first pressing cylinder 5, the installation space, and the second pressing cylinder 6. The middle section of the deformable grating fiber is bonded to point A of the strain member 32 and point B of the weight 31, respectively. Point A is a fixed point, while point B moves under the swing of the weight 31. Therefore, when the inclination angle of the measured object changes, the weight 31 causes the deformable core 33 to deform, resulting in a change in the position of point B, which in turn causes the deformable grating fiber to lengthen or shorten. In other words, the deformable grating fiber is deformed under the action of the weight 31.
[0032] The deformed grating optical fiber passes through the pressing cylinder 1 5, is bonded above the weight hammer 31 and the strain member 32, and passes through the pressing cylinder 2 6. The deformed grating optical fiber is compressed by a hose at the connection between the deformed grating optical fiber and the pressing cylinder 1 5 and the pressing cylinder 2 6. The middle section of the deformed grating optical fiber is bonded at point A and point B respectively.
[0033] A temperature compensation zone 7 is provided on the side of the weight hammer 31, and a temperature compensation grating fiber is provided in the temperature compensation zone 7. The temperature compensation grating fiber is bonded to the temperature compensation zone 7. The top of the temperature compensation grating fiber is fused together with the deformed grating fiber. Since the grating fiber will only be deformed under the action of temperature and pressure, the temperature compensation grating fiber is provided to eliminate the interference of temperature on the deformed grating fiber. The deformed grating fiber passes through the pressure cylinder 2 6 and is connected to the grating fiber demodulator, and the wavelength of the deformed grating fiber and the temperature compensation grating fiber is measured by the grating fiber demodulator. The specific process is: a beam of light is injected into the deformed grating fiber, and a beam of reflected light is generated at this time. The information of the reflected light is transmitted to the demodulator, and the demodulator then decodes it to achieve the wavelength measurement of the grating fiber.
[0034] The wavelengths of the deformed grating fiber and the temperature-compensated grating fiber are measured by a grating fiber interrogator, and then the inclination angle is calculated. The calculation formula of the inclination angle is:
[0035] Δθ=[(λ ε -λ ε0 )-β(λ T -λ T0 )]*K
[0036] Among them, λ ε is the current measurement wavelength of the deformed grating fiber, λ ε0 is the initial wavelength of the deformed grating fiber after installation, λ T is the current measurement wavelength of the temperature-compensated grating fiber, λ T0is the initial wavelength of the temperature-compensated grating fiber after installation, K is the sensitivity coefficient of the weight 31, the size of the sensitivity coefficient varies with the material and size of the weight 31, and β is the temperature coefficient of the surrounding environment. The strain wavelength of the deformed grating fiber needs to be subtracted from the deformation wavelength of the temperature-compensated grating fiber affected by temperature, that is, (λ ε -λ ε0 )-β(λ T -λ T0 The measurement data obtained by the above formula are shown in Table 1 and Figure 6 .
[0037] Table 1 Measurement data of tilt angle and strain wavelength
[0038] Inclination angle (°) Strain wavelength (nm) 0 1560.0701 -15.084 1559.3779 -12.078 1559.5031 -9.108 1559.6346 -6.066 1559.7765 -3.042 1559.9152 -0.018 1560.0537 2.988 1560.1924 5.994 1560.3412 9.018 1560.4785 12.042 1560.6289 15.102 1560.7887
[0039] The specific connection methods of each part all adopt conventional means such as mature bolts, rivets, welding, etc. in the existing technology. The machinery, parts and equipment all adopt conventional models in the existing technology. In addition, the circuit connection adopts the conventional connection method in the existing technology, which will not be described in detail here.
[0040] Therefore, the fiber Bragg grating inclinometer of the utility model using the above structure can eliminate the interference of surrounding complex environmental factors and reduce the measurement error of the device.
[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.
Claims
1. A fiber Bragg grating inclinometer, characterized in that: The encapsulation shell includes an outer shell and a sealing end cover installed above the outer shell. A fixed base plate is provided at the bottom of the outer shell. An installation space is formed between the outer shell and the sealing end cover. A deformation component is provided in the installation space. Corresponding bolt mounting holes are provided at the four corners of the sealing end cover and the outer shell. The end cover and the outer shell are fixedly connected by bolts.
2. The fiber Bragg grating inclinometer according to claim 1, characterized in that: A first pressing cylinder and a second pressing cylinder are respectively provided on both sides of the shell.
3. The fiber Bragg grating inclinometer according to claim 2, characterized in that: The deformation assembly includes a weight hammer and a strain piece, wherein the strain piece is arranged above the weight hammer, and the strain piece and the weight hammer are connected through a deformation core.
4. The fiber Bragg grating inclinometer according to claim 3, characterized in that: The deformation component further includes a deformed grating optical fiber, which sequentially passes through the first pressing cylinder, the installation space and the second pressing cylinder.
5. The fiber Bragg grating inclinometer according to claim 4, characterized in that: The middle section of the deformed grating optical fiber is respectively bonded to the strain member and the weight hammer.
6. The fiber Bragg grating inclinometer according to claim 4, characterized in that: A temperature compensation area is provided on the side of the weight hammer, and a temperature compensation grating optical fiber is provided in the temperature compensation area.
7. The fiber Bragg grating inclinometer according to claim 6, characterized in that: The top end of the temperature-compensated grating optical fiber is connected to the deformed grating optical fiber through fusion splicing.