Settlement sensor based on sensibilization structure and measurement method

Abstract

The invention discloses a settlement sensor based on a sensitization structure and a measuring method, the sensor comprises a settlement sensor shell, the sensitization structure and a Fabry-Perot interference cavity, the sensitization structure and a transmission optical fiber are fixed at the top in the settlement sensor shell, and the optical fiber is not in contact with the sensitization structure; a floater is fixed at the bottom of the sensitization structure and is inserted into the liquid; the reflector at the top of the floater serves as a second reflection point, the end face of the optical fiber serves as a first reflection point, and a Fabry-Perot interference cavity is formed between the two reflection points; when the settlement amount changes, the liquid level in the settlement sensor changes, the buoyancy applied to the floater changes, the sensitization structure deforms after being stressed, the length of the Fabry-Perot interference cavity is changed, and the displacement distance of the second reflection point is measured through the Fabry-Perot interference cavity, so that the liquid level change amount and the settlement amount are determined. The method has the advantages of being high in measurement precision, good in long-term stability, free of electromagnetic interference and the like, and is suitable for settlement monitoring of electric power infrastructures, including differential settlement of structures such as pipe galleries and hydropower stations.

Description

Technical Field

[0001] The present invention relates to the technical field of sedimentation monitoring sensors, and in particular to a sedimentation sensor based on a sensitivity enhancement structure and a measuring method. Background Art

[0002] Settlement is an important indicator for monitoring urban integrated pipelines. For example, uneven settlement of a transmission pipeline will crack the lining concrete, allowing pore water in the soil to enter the pipeline and soak the power facilities, causing safety problems and shortening their service life.

[0003] At present, the settlement monitoring of urban integrated pipe corridors usually uses static leveling and other methods. However, the traditional static level based on electrical principles has problems such as weak anti-electromagnetic interference ability, and the static level of fiber Bragg grating has problems such as low accuracy and insufficient long-term stability.

[0004] Existing float-type sedimentation sensors all measure the change in liquid level based on the strain generated by buoyancy, and the change in liquid level is the relative sedimentation. However, the strain generated by the buoyancy of conventional sedimentation sensors is very small, and the sensor sensitivity is low and easily affected by temperature. It is impossible to make the end displacement of the deformation device reach the mm level, but only the micron level, because the temperature effect itself is strain-level, and the sensors based on the principles of fiber grating are themselves temperature sensitive.

[0005] Therefore, it is very necessary to develop a settlement measurement device with advantages such as good long-term stability and strong anti-electromagnetic interference ability. Summary of the invention

[0006] In order to solve the deficiencies in the prior art, the present invention provides a settlement sensor and measurement method based on a sensitivity enhancement structure, which has high measurement accuracy, long service life, is not affected by electromagnetic interference, and can be applied to settlement monitoring of power infrastructure, including uneven settlement of power infrastructure and water conservancy projects with large settlement.

[0007] The present invention adopts the following technical solution.

[0008] The first aspect of the present invention discloses a sedimentation sensor based on a sensitivity enhancement structure, comprising: a sedimentation sensor housing, a sensitivity enhancement structure and a Fabry-Perot interference cavity, wherein the top of the interior of the sedimentation sensor housing is fixed with the sensitivity enhancement structure and a transmission optical fiber, and the transmission optical fiber and the sensitivity enhancement structure are not in contact; a float is fixed at the bottom of the sensitivity enhancement structure, and the float is inserted into a liquid, and the liquid generates buoyancy on the float;

[0009] The reflector on the top of the float is used as the second reflection point, the end face of the transmission optical fiber is used as the first reflection point, the axis of the transmission optical fiber is perpendicular to the plane where the second reflection point is located, and a Fabry-Perot interference cavity is formed between the two reflection points;

[0010] When the amount of sedimentation changes, the liquid level in the sedimentation sensor changes, the buoyancy of the float changes, the sensitivity enhancement structure deforms after being subjected to the force, and the length of the Fabry-Perot interferometer cavity is changed. The moving distance of the second reflection point is measured through the Fabry-Perot interferometer cavity, thereby determining the liquid level change and sedimentation amount.

[0011] Preferably, the transmission optical fiber extends into the interior of the sensor through a sealing joint, with its axis perpendicular to the liquid surface.

[0012] Preferably, the sensitivity enhancement structure is any one of a series cantilever beam sensitivity enhancement structure, an arc-shaped sensitivity enhancement structure, a broken line sensitivity enhancement structure, a wavy line sensitivity enhancement structure or a spiral sensitivity enhancement structure.

[0013] Preferably, the series cantilever beam sensitivity enhancement structure is a symmetrical structure, with each side composed of several beams in different directions connected in series to form a broken line structure. When buoyancy acts on the structure, the beam bends, the float is displaced, the second reflection point moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

[0014] Preferably, the arc-shaped sensitivity enhancement structure is a symmetrical structure with an arc-shaped structure on each side. When buoyancy acts on the arc-shaped structure, the arc-shaped structure bends, the float is displaced, the second reflection point moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

[0015] Preferably, the zigzag-line sensitivity enhancement structure is a symmetrical structure, with each side having a zigzag corrugated structure composed of multiple zigzag lines. When buoyancy acts on the structure, each zigzag line on the zigzag-line sensitivity enhancement structure bends, the float is displaced, the second reflection point moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

[0016] Preferably, the wavy line sensitization structure is a symmetrical structure with a wavy line structure on each side. When buoyancy acts on the structure, the wavy line sensitization structure is compressed as a whole, the float is displaced, the second reflection point moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

[0017] Preferably, the spiral sensitivity enhancement structure is a spiral wire structure, and the transmission optical fiber coincides with the axis of the spiral wire structure. The stiffness of the spiral wire can be adjusted by adjusting the wire diameter and outer diameter of the spiral wire. When the buoyancy force acts on the structure, the spiral sensitivity enhancement structure is compressed as a whole, the float is displaced, the second reflection point moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

[0018] The second aspect of the present invention discloses a sedimentation measurement system based on a sensitivity enhancement structure, comprising the aforementioned sedimentation sensor, a spectrum demodulator and a water tank;

[0019] The transmission optical fiber on the sedimentation sensor is connected to a spectrum demodulator. When multiple sedimentation sensors are used in series, the transmission optical fiber of each sedimentation sensor is connected to the spectrum demodulator to collect the Fabry-Perot interference spectrum.

[0020] A water tank is set at a reference point where no settlement occurs, and a settlement sensor is arranged inside the water tank;

[0021] Each sedimentation sensor has a liquid hole at the bottom, and the liquid areas of multiple sedimentation sensors are connected through a liquid through pipe; each sedimentation sensor has a ventilation pipe in the gas area, and the gas areas of multiple sedimentation sensors are connected through the ventilation pipe, and the liquid area and gas area of ​​one of the sedimentation sensors are connected to the water tank through the liquid through pipe and the ventilation pipe respectively.

[0022] The third aspect of the present invention discloses a sedimentation measurement method, based on the sedimentation measurement system based on the sensitivity enhancement structure, comprising the following steps:

[0023] Install multiple settlement sensors in series at equal heights;

[0024] A water tank is set at a reference point where no sedimentation occurs, and the liquid area of ​​the water tank is connected to the liquid areas of all sedimentation sensors; the gas area of ​​the water tank is connected to the gas areas of all sedimentation sensors;

[0025] Insert another sedimentation sensor into the reference point water tank as the reference point liquid level calibration, and use the sedimentation sensor to measure the liquid change in the reference point water tank;

[0026] The actual settlement of the measured point is obtained by subtracting the liquid level change in the reference point water tank from the liquid level change measured by each settlement sensor.

[0027] The beneficial effect of the present invention lies in that, compared with the prior art, the sedimentation sensor provided by the present invention is based on the principle of optical fiber Fabry-Perot interference. The buoyancy of the float is applied to the sensitivity enhancement structure, so that the end of the sensitivity enhancement structure undergoes a large displacement. Moreover, the sensitivity enhancement structure is a symmetrical structure and does not affect the verticality of the optical fiber and the reflector at all times, thereby changing the length of the Fabry-Perot interference cavity. According to the calibration formula between the Fabry-Perot interference cavity length and the sedimentation amount (liquid level change), the sedimentation amount (liquid level change) can be measured.

[0028] Since the components of Fabry-Perot interferometry are non-contact, there will be no fatigue and low precision problems caused by object deformation, and there will be no electromagnetic interference problem. The settlement sensor provided by the present invention has the beneficial effects of high precision, long life, anti-electromagnetic interference and no zero drift, and can be used to measure the settlement in tunnels, pipe galleries, buildings, water conservancy projects and geological projects, including uneven settlement of power infrastructure and water conservancy projects with large settlement. It can not only measure the settlement of each measuring point, but also measure the relative settlement between two measuring points. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the principle of the optical fiber Fabry-Perot interferometer cavity provided in an embodiment of the present invention;

[0030] Figure 2 A schematic diagram of the structure of a first sedimentation sensor based on a sensitivity enhancement structure provided in an embodiment of the present invention;

[0031] Figure 3 A schematic diagram of the structure of a second sedimentation sensor based on a sensitivity enhancement structure provided in an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the structure of a third sedimentation sensor based on a sensitivity enhancement structure provided in an embodiment of the present invention;

[0033] Figure 5 A schematic diagram of the structure of a fourth sedimentation sensor based on a sensitivity enhancement structure provided in an embodiment of the present invention;

[0034] Figure 6 A schematic diagram of the structure of a fifth sedimentation sensor based on a sensitivity enhancement structure provided in an embodiment of the present invention;

[0035] Figure 7 Interference spectra of the sedimentation sensor under different sedimentation amounts / liquid levels provided in the embodiments of the present invention;

[0036] Figure 8 A curve diagram showing the relationship between the Fabry-Perot interferometer cavity length and the sedimentation amount / liquid level change amount provided in an embodiment of the present invention;

[0037] Fig. 9 It is a schematic diagram of the structure of the sedimentation sensor system provided in an embodiment of the present invention.

[0038] Explanation of the accompanying drawings: 1. First reflection point; 2. Second reflection point; 3. Transmission optical fiber; 4. Float; 5. Gas area; 6. Liquid; 7. Optical fiber sealing joint; 8. Sensor housing; 9. Arc-shaped sensitivity enhancement structure; 10. Series cantilever beam sensitivity enhancement structure; 11. Wave-shaped sensitivity enhancement structure; 12. Broken-line sensitivity enhancement structure; 13. Spiral sensitivity enhancement structure; 14. Liquid passage tube; 15. Ventilation tube; 16. Water tank; 20. Spectral demodulator. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention clearer, the technical scheme of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The embodiments described in this application are only part of the embodiments of the present invention, not all of them. Based on the spirit of the present invention, other embodiments obtained by ordinary technicians in this field without creative work are all within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] Embodiment 1 of the present invention provides a sedimentation sensor based on optical fiber Fabry-Perot interference, comprising: a sedimentation sensor housing 8, a sensitivity enhancement structure and a Fabry-Perot interference cavity.

[0044] A sensitivity enhancement structure and a transmission optical fiber 3 are fixed to the top of the interior of the sedimentation sensor housing 8, and the transmission optical fiber 3 and the sensitivity enhancement structure are not in contact; a float 4 is fixed to the bottom of the sensitivity enhancement structure, a portion of the length of the float 4 is inserted into the liquid 6, and the reflector on the top of the float 4 serves as the second reflection point 2; the end face of the optical fiber is the first reflection point 1, and the axis of the transmission optical fiber 3 is perpendicular to the plane where the second reflection point 2 is located, and a Fabry-Perot interference cavity is formed between the two reflection points.

[0045] The transmission optical fiber 3 extends into the interior of the sensor through the sealing joint 7, and the axis of the transmission optical fiber 3 is perpendicular to the liquid surface.

[0046] A sensitivity enhancement structure is arranged at the top inside the sensor housing 8, and the sensitivity enhancement structure is any one of a series cantilever beam sensitivity enhancement structure, an arc-shaped sensitivity enhancement structure, a broken line-shaped sensitivity enhancement structure, a wave-shaped sensitivity enhancement structure, and a spiral-shaped sensitivity enhancement structure. The structure is characterized in that a bending structure is adopted to reduce the rigidity, and under the action of a small buoyancy, a large displacement can occur at the ends, and the maximum principal strain on the structure is small, plastic deformation is not easy to occur, and fatigue resistance is good.

[0047] The above five sensitivity enhancement structures can significantly reduce the stiffness of the load-bearing components and significantly increase the displacement of the second reflection point relative to the first reflection point under the same buoyancy, thereby improving the sensitivity of the sensor.

[0048] When the amount of sedimentation changes, the liquid level in the sedimentation sensor changes, causing the buoyancy of the float 4 to change, and the sensitivity enhancement structure deforms after being subjected to the force, driving the reflector / second reflection point 2 to move, and the relationship between the optical fiber end face / first reflection point 1 changes, that is, the length of the FP interferometer cavity is changed. The moving distance of the reflector / second reflection point 2 is measured through the FP interferometer cavity to determine the amount of liquid level change and sedimentation.

[0049] like Figure 1 As shown, the optical device of the optical path diagram of the settlement sensor in this embodiment is composed of a first reflection point 1, a second reflection point 2, a transmission optical fiber 3 and a float top 4. Among them, the first reflection point 1 is the end face of the transmission optical fiber 3, and the end face is perpendicular to the axis of the transmission optical fiber 3; the second reflection point 2 is a side of the float top 4 close to the transmission optical fiber 3, and its reflectivity is between 0% and 100%, usually higher than 4%; the multiple reflected lights between the first reflection point and the second reflection point interfere with each other to form a Fabry-Perot interference cavity; the other end of the transmission optical fiber 3 is connected to a spectrum demodulator 20, which can emit width light and collect the Fabry-Perot interference spectrum. The interference spectrum is usually a sine curve, such as Figure 7 shown.

[0050] like Figure 2As shown, the series cantilever beam sensitivity enhancement structure 10 is a symmetrical structure, and each side is connected in series by several beams in different directions to form a "Z"-shaped low-rigidity broken line structure; when the buoyancy generated by the float acts on the structure, all the beams are bent. Compared with the deflection of the traditional diaphragm under pressure, the deflection change is increased from the order of microns to the order of hundreds of microns. Since the resolution of the Fabry-Perot interferometer cavity remains unchanged, increasing the deflection change (range) can greatly improve the resolution of the sensor (resolution / range), the float 4 undergoes a large displacement, the second reflection point 2 moves, and the length of the Fabry-Perot interferometer cavity formed by the two reflection points changes. By calibrating the relationship between the sedimentation amount and the Fabry-Perot interferometer cavity length, the sedimentation amount can be determined by the change in the Fabry-Perot cavity length.

[0051] It is worth noting that the beams can be connected in different ways as long as all the beams are not in a straight line to meet the requirement of reducing the sensitivity enhancement stiffness.

[0052] like Figure 3 As shown, the arc-shaped sensitivity enhancement structure 9 is a symmetrical structure, with an arc-shaped structure on each side, forming a low-rigidity structure, and the deflection change is increased from the micron order to the hundred micron order; the measurement method is the same as Figure 2 The structure is the same, and by calibrating the relationship between the sedimentation amount and the Fabry-Perot interferometer cavity length, the sedimentation amount can be determined by the change in the Fabry-Perot cavity length.

[0053] like Figure 4 As shown, the folded line-shaped sensitivity enhancement structure 12 is a symmetrical structure, and each side has a folded line corrugated structure 12 composed of multiple folded lines, which can greatly reduce the structural rigidity and improve the sensitivity of the sensor to buoyancy. Figure 2 Compared with the tandem structure shown in Figure 2 The stiffness of the structure should be low; when buoyancy acts on the structure, compared with the deflection of the traditional diaphragm under pressure, the change in deflection can be increased from the order of microns to the order of millimeters. Since the resolution of the Fabry-Perot interferometer cavity remains unchanged, increasing the change in deflection (range) can greatly improve the resolution of the sensor (resolution / range). Each broken line on the broken line sensitivity enhancement structure 12 is bent, the float 4 undergoes a large displacement, the second reflection point 2 moves, and the length of the Fabry-Perot interferometer cavity formed by the two reflection points changes. By calibrating the relationship between the sedimentation amount and the Fabry-Perot interferometer cavity length, the sedimentation amount can be determined by the change in the Fabry-Perot cavity length.

[0054] like Figure 5 As shown, the wavy line-shaped sensitivity enhancement structure 11 is a symmetrical structure, with a wavy line-shaped structure on each side. The measurement mechanism is similar to Figure 4 The structure is the same, and the deflection change can also be increased from the micron order to the millimeter order. The difference is Figure 5The structure changes the broken line corrugated structure into a curved corrugated structure, which is more convenient to process. By calibrating the relationship between the sedimentation amount and the Fabry-Perot interferometer cavity length, the sedimentation amount can be determined by the change in the Fabry-Perot cavity length.

[0055] like Figure 6 As shown, the spiral sensitivity enhancement structure 13 is a spiral structure, and the transmission optical fiber 3 coincides with the axis of the spiral structure 13. The spiral structure is a spring structure. The stiffness of the spiral can be adjusted by adjusting the diameter and outer diameter of the spiral 13; the larger the diameter, the smaller the outer diameter, and the fewer the number of turns, the greater the stiffness. Compared with the deflection of the traditional diaphragm under pressure, the deflection change can be increased from the order of micrometers to the order of millimeters. It is only necessary to adjust the elastic coefficient of the spiral structure, that is, to adjust the diameter of the spiral. The larger the diameter, the smaller the outer diameter, and the fewer the number of turns, the greater the elastic coefficient, and the deflection change can be controlled; when the buoyancy acts on the structure, the spiral sensitivity enhancement structure 13 is compressed as a whole, the float 4 is displaced to a large extent, the second reflection point 2 moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes. By calibrating the relationship between the sedimentation amount and the length of the Fabry-Perot interference cavity, the sedimentation amount can be determined by the change in the length of the Fabry-Perot cavity.

[0056] Figure 7 The reflection spectrum of the sedimentation / liquid level sensor measured by the spectrum demodulator 20 when the sedimentation amount is 0, 90, 210, and 200 mm, namely, the Fabry-Perot interference spectrum. The interference cavity length under different sedimentation amounts is calculated by demodulation, and the linear relationship between the change in the interference cavity length y and the sedimentation amount x is calibrated, y = -1.3065x, such as Figure 8 shown.

[0057] like Fig. 9 As shown, embodiment 2 of the present invention also provides a sedimentation measurement system, which is composed of multiple sedimentation sensors. Each sedimentation sensor has a liquid hole at the bottom, and the liquid areas of the multiple sedimentation sensors are connected through a liquid pipe 14; the gas area 5 of each sedimentation sensor has a ventilation pipe 15, and the liquid areas of the multiple sedimentation sensors are connected through the ventilation pipe 15. There is a water tank 16 at the end reference point where no sedimentation occurs. The liquid area and the gas area of ​​one of the sedimentation sensors are connected to the water tank 16 through the liquid pipe 14 and the ventilation pipe 15 respectively, so as to form a settlement measurement system based on a static level.

[0058] When the sedimentation sensors are used in series, the transmission optical fiber 3 of each sedimentation sensor is connected to the spectrum demodulator 20 to collect the Fabry-Perot interference spectrum.

[0059] Embodiment 3 of the present invention provides a sedimentation measurement method, comprising the following steps:

[0060] Step 1: Install multiple settlement sensors at equal heights;

[0061] Step 2: Set a water tank at a reference point where no settlement occurs, connect the liquid area of ​​the water tank with the liquid area of ​​the settlement sensor, and connect the liquid areas of all the settlement sensors; connect the gas area of ​​the water tank with the gas area of ​​the settlement sensor, and connect the gas areas of all the settlement sensors to form a settlement measurement system;

[0062] Step 3, insert another sedimentation sensor into the reference point water tank as the reference point liquid level calibration, and use the sedimentation sensor to measure the liquid change in the reference point water tank;

[0063] Step 4, using a series of sedimentation sensors connected in series to measure the level change of the liquid in the sedimentation sensors respectively;

[0064] Step 5: Subtract the liquid level change in the reference point water tank from the liquid level change measured by each sedimentation sensor to obtain the actual sedimentation of the measured point.

[0065] In a preferred but non-limiting embodiment of the present invention, the sedimentation sensor in step 1 is one or more sedimentation sensors, and the multiple sedimentation sensors are installed at the same height with equal intervals to form a sedimentation sensor system.

[0066] The liquid area of ​​the reference point water tank is communicated with the sedimentation sensor in the sedimentation sensor system that is closest to the water tank; the gas area of ​​the water tank is communicated with the gas area of ​​the sedimentation sensor in the sedimentation sensor system that is closest to the water tank.

[0067] Furthermore, if Figure 8 As shown, the method for measuring the liquid level change of the sedimentation sensor is as follows:

[0068] Draw a curve diagram of the relationship between the Fabry-Perot interferometer cavity length and the sedimentation amount;

[0069] The relationship curve is fitted so that the sedimentation amount (liquid level change) and the Fabry-Perot interferometer cavity length satisfy a linear relationship; and a relationship between the Fabry-Perot interferometer cavity length and the sedimentation amount is obtained.

[0070] A preferred but non-limiting formula for calculating the amount of sedimentation is as follows:

[0071] y=-1.3065x

[0072] Where: y represents the sedimentation amount (liquid level change), the unit is mm; x represents the change in the Fabry-Perot interferometer cavity length, the unit is μm.

[0073] The beneficial effect of the present invention lies in that, compared with the prior art, the sedimentation sensor provided by the present invention is based on the principle of optical fiber Fabry-Perot interference. The buoyancy of the float is applied to the sensitivity enhancement structure, so that the end of the sensitivity enhancement structure undergoes a large displacement. Moreover, the sensitivity enhancement structure is a symmetrical structure and does not affect the verticality of the optical fiber and the reflector at all times, thereby changing the length of the Fabry-Perot interference cavity. According to the calibration formula between the Fabry-Perot interference cavity length and the sedimentation amount (liquid level change), the sedimentation amount (liquid level change) can be measured.

[0074] Since the components of Fabry-Perot interferometry are non-contact, there will be no fatigue and low precision problems caused by object deformation, and there will be no electromagnetic interference problem. The settlement sensor provided by the present invention has the beneficial effects of high precision, long life, anti-electromagnetic interference and no zero drift, and can be used to measure the settlement in tunnels, pipe galleries, buildings, water conservancy projects and geological projects, including uneven settlement of power infrastructure and water conservancy projects with large settlement. It can not only measure the settlement of each measuring point, but also measure the relative settlement between two measuring points.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that any structure that uses curves, broken lines or combined structures to significantly reduce the stiffness of the sensitivity enhancement structure is within the protection scope of the present invention: the specific implementation methods of the present invention can still be modified or replaced by equivalents, and any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A sedimentation sensor based on a sensitivity enhancement structure, comprising: The sedimentation sensor housing (8), the sensitivity enhancement structure and the Fabry-Perot interference cavity are characterized by: A sensitivity enhancement structure and a transmission optical fiber (3) are fixed to the top of the interior of the sedimentation sensor housing (8), and the transmission optical fiber (3) and the sensitivity enhancement structure are not in contact; a float (4) is fixed to the bottom of the sensitivity enhancement structure, and the float (4) is inserted into the liquid (6), and the liquid (6) generates buoyancy on the float (4); The reflector on the top of the float (4) serves as the second reflection point (2), the end face of the transmission optical fiber (3) serves as the first reflection point (1), the axis of the transmission optical fiber (3) is perpendicular to the plane where the second reflection point (2) is located, and a Fabry-Perot interference cavity is formed between the two reflection points; When the amount of sedimentation changes, the liquid level in the sedimentation sensor changes, the buoyancy of the float (4) changes, the sensitivity enhancement structure deforms after being subjected to the force, and the length of the Fabry-Perot interference cavity is changed. The moving distance of the second reflection point (2) is measured through the Fabry-Perot interference cavity, thereby determining the amount of liquid level change and the amount of sedimentation.

2. A sedimentation sensor based on a sensitivity enhancement structure according to claim 1, characterized in that: The transmission optical fiber (3) extends into the interior of the sensor through a sealing joint (7), and its axis is perpendicular to the liquid surface of the liquid (6).

3. The sedimentation sensor based on the sensitivity enhancement structure according to claim 1 is characterized in that: The sensitivity enhancement structure is any one of a series cantilever beam sensitivity enhancement structure (10), an arc-shaped sensitivity enhancement structure (9), a broken line-shaped sensitivity enhancement structure (12), a wavy line-shaped sensitivity enhancement structure (11) or a spiral-shaped sensitivity enhancement structure (13).

4. A sedimentation sensor based on a sensitivity enhancement structure according to claim 3, characterized in that: The series cantilever beam sensitivity enhancement structure (10) is a symmetrical structure, with each side being composed of several beams in different directions connected in series to form a broken line structure. When buoyancy acts on the structure, the beam bends, the float (4) is displaced, the second reflection point (2) moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

5. The sedimentation sensor based on the sensitivity enhancement structure according to claim 3 is characterized in that: The arc-shaped sensitivity enhancement structure (9) is a symmetrical structure, with an arc-shaped structure on each side. When the buoyancy acts on the arc-shaped structure, the arc-shaped structure bends, the float (4) is displaced, the second reflection point (2) moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

6. The sedimentation sensor based on the sensitivity enhancement structure according to claim 3 is characterized in that: The zigzag-line sensitivity enhancement structure (12) is a symmetrical structure, and each side has a zigzag-line corrugated structure composed of multiple zigzag lines. When buoyancy acts on the structure, each zigzag line on the zigzag-line sensitivity enhancement structure (12) bends, the float (4) is displaced, the second reflection point (2) moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

7. The sedimentation sensor based on the sensitivity enhancement structure according to claim 3 is characterized in that: The wavy line-shaped sensitivity enhancement structure (11) is a symmetrical structure, with a wavy line-shaped structure on each side. When buoyancy acts on the structure, the wavy line-shaped sensitivity enhancement structure (12) is compressed as a whole, the float (4) is displaced, the second reflection point (2) moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

8. The sedimentation sensor based on the sensitivity enhancement structure according to claim 3 is characterized in that: The spiral sensitivity enhancement structure (13) is a spiral wire structure. The transmission optical fiber (3) coincides with the axis of the spiral wire structure (13). The stiffness of the spiral wire can be adjusted by adjusting the wire diameter and outer diameter of the spiral wire. When buoyancy acts on the structure, the spiral sensitivity enhancement structure (13) is compressed as a whole, the float (4) is displaced, the second reflection point (2) moves, and the length of the Fabry-Perot interference cavity formed by the two reflection points changes.

9. A sedimentation measurement system based on a sensitivity enhancement structure, characterized in that: It comprises a sedimentation sensor, a spectrum demodulator (20) and a water tank (16) according to any one of claims 1 to 8; The transmission optical fiber (3) on the sedimentation sensor is connected to a spectrum demodulator (20). When a plurality of sedimentation sensors are used in series, the transmission optical fiber (3) of each sedimentation sensor is connected to the spectrum demodulator (20) for collecting Fabry-Perot interference spectrum. A water tank (16) is arranged at a reference point where no settlement occurs, and a settlement sensor is arranged inside the water tank; Each sedimentation sensor has a liquid through hole at the bottom, and the liquid areas of the multiple sedimentation sensors are connected via a liquid through pipe (14); each sedimentation sensor has a gas area (5) having a ventilation pipe (15), and the gas areas of the multiple sedimentation sensors are connected via the ventilation pipe (15); the liquid area and the gas area of ​​one of the sedimentation sensors are connected to the water tank (16) via the liquid through pipe (14) and the ventilation pipe (15), respectively.

10. A sedimentation measurement method, based on the sedimentation measurement system based on a sensitivity enhancement structure according to claim 9, characterized in that: The following steps are involved: Install multiple settlement sensors in series at equal heights; A water tank is set at a reference point where no sedimentation occurs, and the liquid area of ​​the water tank is connected to the liquid areas of all sedimentation sensors; the gas area of ​​the water tank is connected to the gas areas of all sedimentation sensors; Insert another sedimentation sensor into the reference point water tank as the reference point liquid level calibration, and use the sedimentation sensor to measure the liquid change in the reference point water tank; The actual settlement of the measured point is obtained by subtracting the liquid level change in the reference point water tank from the liquid level change measured by each settlement sensor.

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