Displacement sensor based on distributed optical fibers and displacement sensor measuring system

Abstract

The utility model discloses a displacement sensor based on distributed optical fibers and a displacement sensor measuring system. The displacement sensor comprises a housing, two optical fibers which are arranged in parallel in a tensioning manner, and a group of sliding parts which are symmetrically arranged. The sliding part comprises a measuring arm, a sliding wheel and an arc-shaped wedge block, the optical fiber is in contact with the arc surface of the arc-shaped wedge block to form a bulge, and the other end of the measuring arm is connected with a to-be-measured object; when the object to be measured displaces, the measuring arm is driven, so that the sliding part slides leftwards / rightwards, the position of the bulge is changed, and the total displacement is calculated through the position of the bulge. According to the utility model, the sliding part with the arc-shaped wedge block is adopted based on an optical fiber bending effect, displacement is calculated according to the change of the position of the bulge, and the problem that a single optical fiber sensor cannot capture bidirectional displacement is solved; the displacement of an object is captured by adopting the two symmetrically arranged measuring arms, so that the accurate measurement of the total displacement of the object is realized.

Description

Technical Field

[0001] The utility model relates to, in particular to, a displacement sensor based on distributed optical fiber and a displacement sensor measurement system. Background Art

[0002] Displacement monitoring plays a crucial role in structural health monitoring, as excessive deformation can lead to structural instability and even serious safety accidents. However, traditional displacement sensors are susceptible to electromagnetic interference, limiting their application and accuracy, making them difficult to meet monitoring needs in complex environments. In contrast, fiber optic displacement sensors offer advantages such as strong resistance to electromagnetic interference, corrosion resistance, compact size, and high flexibility, making them particularly suitable for displacement monitoring in harsh environments. However, since the object being measured may move in both directions, a single fiber optic sensor cannot capture this displacement. Utility Model Content

[0003] Purpose of the utility model: The purpose of the utility model is to provide a distributed optical fiber sensor based on the optical fiber bending effect. Another purpose of the invention is to provide a displacement sensor measurement system based on distributed optical fiber.

[0004] Technical solution: The distributed optical fiber-based displacement sensor of the utility model includes a housing, an optical fiber and a sliding part; the optical fiber is two optical fibers arranged in parallel and tightened, and a sliding part is arranged for each optical fiber; the sliding part includes a measuring arm, a sliding wheel and an arc-shaped wedge block, the optical fiber contacts the arc surface of the arc-shaped wedge block to form a protrusion, the arc-shaped wedge block is connected to the sliding wheel, the measuring arm and the arc-shaped wedge block are fixedly connected, and the other end of the measuring arm is connected to the object to be measured; the sliding part is a left sliding part and a right sliding part, which are respectively arranged at both ends of the housing; when the object to be measured is displaced, the measuring arm is driven, causing the sliding part to slide left / right, changing the position of the protrusion, and the total displacement is calculated based on the position of the protrusion.

[0005] Preferably, the measuring arm is parallel to the optical fiber.

[0006] Preferably, a sliding groove is provided at the bottom of the shell.

[0007] Preferably, the distance between the two optical fibers is 2 cm to 10 cm.

[0008] Preferably, the arc surface radius of the arc wedge is 0.5 cm-10 cm, and the arc surface angle is 10-60°.

[0009] Preferably, the arc surface of the arc-shaped wedge block is provided with a limiting groove.

[0010] The displacement sensor measurement system based on distributed optical fiber of the present invention comprises: a light source, a measuring unit, a calculating unit and the above-mentioned displacement sensor based on distributed optical fiber;

[0011] The light source and the measuring unit are arranged on an end face of one side of the optical fiber;

[0012] The measuring unit is used to measure the reflected light and determine the position of the protrusion;

[0013] The calculation unit is used to calculate the total displacement based on the protrusion position measured by the measuring unit.

[0014] Beneficial effects: Compared with the existing technology, the present invention has the following advantages: 1. The present invention adopts a sliding part with an arc-shaped wedge block based on the bending effect of the optical fiber, calculates the displacement according to the change of the protrusion position, and solves the problem that a single optical fiber sensor cannot capture bidirectional displacement; 2. The present invention forms a distributed structure by arranging two optical fibers and left and right sliding parts, thereby improving the accuracy of the optical fiber sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a top view of the utility model;

[0016] Figure 2 It is the main view of the utility model. DETAILED DESCRIPTION

[0017] The technical solution of the present utility model will be further described below with reference to the accompanying drawings.

[0018] The distributed optical fiber displacement sensor described in this utility model comprises a housing 1, two optical fibers 3, and a pair of sliding parts. The housing 1 has a sliding groove 5 at its bottom, and the sliding parts slide within the groove 5. The sliding parts comprise a left sliding part and a right sliding part, respectively disposed at opposite ends of the housing. The two optical fibers 3 are arranged parallel and tautly spaced 2 to 10 cm apart, with one sliding part corresponding to each optical fiber 3.

[0019] The sliding part includes a measuring arm 4, a sliding wheel 6 and an arc-shaped wedge 2. One end of the measuring arm 4 is fixedly connected to the arc-shaped wedge 2, and the other end is connected to the object to be measured, and the measuring arm 4 is parallel to the optical fiber 3. The arc-shaped wedge 2 is connected to the sliding wheel 6, and the sliding wheel 6 is located in the sliding groove 5. The optical fiber 3 contacts the arc surface of the arc-shaped wedge 2 to form a bulge. The radius of the arc surface of the arc-shaped wedge 2 is 0.5cm-10cm, and the angle of the arc surface is 10 to 60°. Preferably, the arc surface of the arc-shaped wedge 2 is provided with a limit groove for limiting the position of the optical fiber. When the object to be measured is displaced, the measuring arm 4 is driven to make the sliding part slide left / right, change the position of the bulge, and calculate the total displacement through the position of the bulge.

[0020] The displacement sensor measurement system based on distributed optical fiber described in the utility model comprises: a light source, a measuring unit, a computing unit and the above-mentioned displacement sensor based on distributed optical fiber;

[0021] The light source and the measuring unit are arranged on an end face of one side of the optical fiber;

[0022] The measuring unit is used to measure the reflected light and determine the position of the protrusion;

[0023] The calculation unit is used to calculate the total displacement based on the protrusion position measured by the measuring unit.

[0024] The distributed optical fiber displacement sensor system described in this utility model reflects the displacement of an object by measuring the bending of the optical fiber caused by the movement of the curved wedge 2 located in the sliding portion of the sliding groove 5. The sliding of the curved wedge 2 causes the optical fiber to bend accordingly, and the location of the bending changes accordingly. Based on the signal changes in the optical fiber, the measurement unit can determine the strain at different locations of the optical fiber using OTDR or OFDR technology.

[0025] Assuming the initial bending point of the optical fiber is P0 and the position after strain is P1, the displacement ΔL caused by strain can be expressed as

[0026] ΔL=|P1-P0|

[0027] The measurement unit is an OTDR or OFDR device, which can obtain the actual position change ΔL of the bending point in the optical fiber and further calculate the total displacement between the two bending points.

[0028] The utility model uses two symmetrically arranged measuring arms to capture the displacement of the object and achieve accurate measurement of the total displacement of the object. The initial position is set to 0, and the left and right sliding distances measured by the measuring unit are Δx L and Δx R , then the total displacement D can be calculated as:

[0029] D=Δx L +Δx R

[0030] To ensure measurement accuracy, the system requires regular calibration to ensure that the OTDR and OFDR instruments can correctly interpret signal variations in the optical fiber. Errors that need to be considered include signal distortion caused by fiber bending nonlinearity and fiber refractive index drift due to temperature changes. By analyzing and correcting these errors, measurement accuracy can be further improved.

Claims

1. A displacement sensor based on distributed optical fiber, characterized in that: The invention comprises a housing (1), an optical fiber (3) and a sliding part; the optical fiber (3) is a parallel tensioned arrangement of two optical fibers (3), and a sliding part is correspondingly arranged for each optical fiber (3); the sliding part comprises a measuring arm (4), a sliding wheel (6) and an arc-shaped wedge (2); the optical fiber (3) contacts the arc surface of the arc-shaped wedge (2) to form a bulge, the arc-shaped wedge (2) is connected to the sliding wheel (6), the measuring arm (4) and the arc-shaped wedge (2) are fixedly connected, and the other end of the measuring arm (4) is connected to the object to be measured; the sliding part comprises a left sliding part and a right sliding part, which are respectively arranged at two ends of the housing; when the object to be measured is displaced, the measuring arm is driven to make the sliding part slide left / right, thereby changing the position of the bulge, and the total displacement is calculated according to the position of the bulge.

2. The distributed optical fiber displacement sensor according to claim 1, characterized in that: The measuring arm (4) is parallel to the optical fiber (3).

3. The distributed optical fiber displacement sensor according to claim 1, characterized in that: The bottom of the housing (1) is provided with a sliding groove (5).

4. The distributed optical fiber-based displacement sensor according to claim 1, characterized in that: The distance between the two optical fibers (3) is 2 cm to 10 cm.

5. The distributed optical fiber-based displacement sensor according to claim 1, characterized in that: The arc surface radius of the arc-shaped wedge (2) is 0.5 cm to 10 cm, and the arc surface angle is 10 to 60 degrees.

6. The distributed optical fiber-based displacement sensor according to claim 1, characterized in that: The arc surface of the arc-shaped wedge (2) is provided with a limiting groove.

7. A displacement sensor measurement system based on distributed optical fiber, characterized in that: include: A light source, a measuring unit, a calculating unit and the distributed optical fiber-based displacement sensor according to claim 1; The light source and the measuring unit are arranged on an end face of one side of the optical fiber; The measuring unit is used to measure the reflected light and determine the position of the protrusion; The calculation unit is used to calculate the total displacement based on the protrusion position measured by the measuring unit.

Images