CN203881299U

CN203881299U - Sliding mass depth displacement sensor based on fiber grating displacement detection

Info

Publication number: CN203881299U
Application number: CN201420108247.0U
Authority: CN
Inventors: 姚飞; 肖丹谊; 蒋丽娟; 李鹏; 黄少鹏
Original assignee: GUILIN G-LINK TECHNOLOGY Co Ltd
Current assignee: GUILIN G-LINK TECHNOLOGY Co Ltd
Priority date: 2014-03-11
Filing date: 2014-03-11
Publication date: 2014-10-15
Anticipated expiration: 2024-03-11

Abstract

The utility model discloses a sliding mass depth displacement sensor based on fiber grating displacement detection. The sliding mass depth displacement sensor comprises an upper connection rod, an upper sliding block, an upper fixing rod, a bearing, a lower fixing rod, a lower sliding block and a lower connection rod which are sequentially connected in a sealing pipe from up to down, and further comprises four sensing units composed of four sensing base boards and four fiber gratings, the four sensing units respectively measure displacement amount in four directions, the four sensing units are connected in a tail-to-head mode through heat fusion welding to form a fiber grating string, and tail and head ends of the fiber grating string are respectively connected with a communication cable and other fiber grating depth displacement sensors. According to the sensor, change amount of a center wave length of the fiber grating is measured, deformation amount of the sensing base boards is calculated, depth displacement amount of the sensing units in the directions can be calculated, and thereby directions and amount of depth displacement can be calculated through vector composition in combination with the displacement amount in the four different directions.

Description

A kind of sliding mass deep displacement sensor of surveying based on fiber grating displacement

Technical field

The utility model belongs to sensory field of optic fibre, particularly a kind of sliding mass deep displacement sensor of surveying based on fiber grating displacement.

Background technology

Landslide is a kind of disaster common in engineering, geological problem, for preventing trouble before it happens, strengthens the presentiment and preventing of landslide, must monitor landslide, realizes the early prediction of landslide, and this is very important for reducing casualty loss.

Fiber grating is the optical fibre device in photoelectron technology field extensive application prospects such as optical fiber communication, Fibre Optical Sensors, fiber-optic grating sensor is widely used in the engineering health monitorings such as bridge, water conservancy, building with its distinctive technical advantage, the information such as main test surfaces deformation, inner deformation, temperature.For landslide and Geological Hazards Monitoring, prediction, need to monitor sliding mass deep displacement, the main micro-electro-mechanical sensors (MEMS) that adopts of deep displacement monitoring at present, angle by the inner pendulum of testing sensor is reacted the displacement that tested point occurs, the voltage swing of exporting by pick-up transducers at demodulating end obtains deflection angle, and then calculates the displacement size occurring, and the method adopts electricity sensing, scene needs power supply, and cost is higher.

Summary of the invention

The utility model is for the deficiencies in the prior art, a kind of sliding mass deep displacement sensor of surveying based on fiber grating displacement is provided, fiber grating sensing technology is applied to deep displacement sensing, substitute conventional electrical testing method, test site all adopts passive sensing without power supply, and install convenient, cost is lower.It can test the Displacements Distribution situation in soil body certain depth, and then provides early warning reference for disasteies such as landslides.

The technical scheme that realizes the utility model object is:

A sliding mass deep displacement sensor of surveying based on fiber grating displacement, mainly comprises upper connecting rod, top shoe, upper fixed bar, bearing, lower connecting rod, sliding block, lower fixed bar, sealed tube, four sensing baseplates and four fiber gratings; Upper connecting rod and upper fixed bar are separately fixed at the above and below of top shoe; Lower fixed bar and lower connecting rod are separately fixed at the above and below of sliding block; Upper fixed bar is connected by bearing with lower fixed bar; The xsect of top shoe and sliding block is square, is separately fixed at the upper and lower end of sealed tube; The middle part of sensing baseplate is provided with V-type groove, fiber grating is fixed in V-type groove, a sensing baseplate and a fiber grating form a sensing unit, one end of four sensing baseplates is fixed with four sides of sliding block respectively, four sensing units are measured the displacement of four direction respectively, four sensing units mode by thermal welding joins end to end and forms fiber grating string, and the head and the tail two ends of fiber grating string connect respectively communications optical cable and other fiber grating deep displacement sensor.

Described top shoe and sliding block and sealed tube adopt sealant sealing to fix, and realize the seal isolation to sensor, and whole sensor can directly be embedded in the earth drilling of sliding mass test site.

Described fiber grating is fixed on sensing baseplate with optical cement; One end of sensing baseplate adopts a side of screw and sliding block to fix.

The utility model has been combined ripe optical fiber grating sensing the test of displacement with semi-girder technology, adopt four sensing units to realize respectively the measurement to the sense of displacement of four direction generation and size, by sealed tube, sensor is isolated from the outside, can be directly embedded in tested point.

The utility model has the advantages that: fiber grating is passive light sensing, without scene, powers; Optical fiber grating sensing is optical signal communications, can not be subject to the impact of electromagnetic interference (EMI); Fiber grating is Wavelength demodulation, and signal is from the variation of wavelength, and the fluctuation of watt level can not exert an influence to test result; Whole sensor adopts four sensing units, and the size that not only can test landslide can also be tested the direction that landslide occurs; Adopt fiber Bragg grating sensor, effectively reduced cost.

Accompanying drawing explanation

Fig. 1 is the structural representation of the utility model sensor;

Fig. 2 is the vertical view of the utility model sensor;

Fig. 3 is the upward view of the utility model sensor;

Fig. 4 is the utility model sensor generation deformation schematic diagram;

Fig. 5 is the deformation schematic diagram of the sensing unit of the utility model fiber grating and sensing baseplate formation.

In figure, 1. 5. times fixed bars of fixed bar 4. bearing, 6. sliding block 7. lower connecting rod 8. sealed tube 9. sensing baseplate 10. fiber gratings on upper connecting rod 2. top shoes 3..

embodiment

Below in conjunction with drawings and Examples, the utility model content is further described, but is not to restriction of the present utility model.

Embodiment

With reference to Fig. 1,2 and 3, a kind of sliding mass deep displacement sensor of surveying based on fiber grating displacement of the utility model, comprises upper connecting rod 1, top shoe 2, upper fixed bar 3, bearing 4, lower fixed bar 5, sliding block 6, lower connecting rod 7, sealed tube 8, sensing baseplate 9, fiber grating 10.

Upper connecting rod 1, top shoe 2, upper fixed bar 3 form the first half of sensor; Lower fixed bar 5, sliding block 6, lower connecting rod 7 form the latter half of sensor; The first half is connected by bearing 4 with the latter half.

Upper connecting rod 1 be fixed on top shoe 2 above, upper fixed bar 3 be fixed on top shoe 2 below; Lower connecting rod 7 be fixed on sliding block 5 below, lower fixed bar 5 be fixed on sliding block 6 above; Upper fixed bar 3 is connected by bearing 4 with lower fixed bar 5; The xsect of top shoe 2 and sliding block 6 is square, is separately fixed at the upper and lower end of sealed tube 8; The middle part of sensing baseplate 9 is provided with V-type groove, fiber grating 10 is fixed in V-type groove, a sensing baseplate 9 and a fiber grating 10 form a sensing unit, one end of four sensing baseplates 9 is fixed with four sides of sliding block 6 respectively, four sensing units are measured the displacement of four direction respectively, four sensing units mode by thermal welding joins end to end and forms fiber grating string, and the head and the tail two ends of fiber grating string connect respectively communications optical cable and other fiber grating deep displacement sensor.

With reference to Figure 4 and 5, the utility model sliding mass deep displacement sensor is embedded in the boring of sliding mass to be measured, when the inner generation of sliding mass is slided, the latter half generation relative displacement of the first half of sensor and sensor, because the first half is connected by bearing 4 with the latter half, this relative displacement will be converted to the relative angle of the two, this relative angle is delivered to the inside of sliding mass deep displacement sensor, the top that is fixed on the sensing baseplate 9 on sliding block 6 can be subject to the pressure from top shoe 2, sensing baseplate 9 bends, cause fiber grating 10 that axial deformation occurs, and then the reflection kernel wavelength of change fiber grating 10, thereby the variation of measuring optical fiber grating 10 reflection wavelengths detects the size of displacement.The sensing unit of four different directions detects the size of displacement, by vector, synthesizes, and calculates direction and the size of deep displacement.

The sensing unit that the utility model is comprised of fiber grating 10 and sensing baseplate 9, sensor comprises four sensing units altogether, be separately fixed at four sides of sliding block 6, the middle part of sensing baseplate 9 is processed with V-type groove, use optical fiber glue fiber grating 10 to be fixed on to the middle part of V-type groove, when one end of sensing baseplate 9 is fixed on to sliding block 6, sensing baseplate 9 can be regarded a cantilever beam structure as, when test point generation deep displacement, can there is deformation in sensing baseplate 9, and then drive fiber grating 10 that deformation occurs, sensing baseplate 9 meets following formula with fiber grating 10 center wavelength variation:

In the situation that knowing semi-girder free end deformation size, can know properties of materials, fiber grating 10 center wavelength variation only with the length L of sensing baseplate 9, the fixed position x of fiber grating 10, the thickness d of sensing baseplate 9, the initial wavelength X of fiber grating 10, the several parameters of deformation size h are relevant.

By the variable quantity of measuring optical fiber grating 10 centre wavelengths, calculate the deformation quantity that sensing baseplate 9 occurs, calculate the deep displacement amount of this sensing unit place direction, then in conjunction with the size of the displacement of four different directions, by vector, synthesize, calculate direction and the size of deep displacement.

By changing the size of substrate 9, upper connecting rod 1 and lower connecting rod 7, can make the testing range of landslide deep displacement sensor reach 50mm.

Claims

1. a sliding mass deep displacement sensor of surveying based on fiber grating displacement, is characterized in that: sensor comprises upper connecting rod (1), top shoe (2), upper fixed bar (3), bearing (4), lower fixed bar (5), sliding block (6), lower connecting rod (7), sealed tube (8), four sensing baseplates (9) and four fiber gratings (10); Upper connecting rod (1) and upper fixed bar (3) are separately fixed at the above and below of top shoe (2); Lower fixed bar (5) and lower connecting rod (7) are separately fixed at the above and below of sliding block (6); Upper fixed bar (3) is connected by bearing (4) with lower fixed bar (5); The xsect of top shoe (2) and sliding block (6) is square, is separately fixed at the upper and lower end of sealed tube (8); The middle part of sensing baseplate (9) is provided with V-type groove, fiber grating (10) is fixed in V-type groove, a sensing baseplate (9) and a fiber grating (10) form a sensing unit, one end of four sensing baseplates (9) is fixed with four sides of sliding block (6) respectively, four sensing units mode by thermal welding joins end to end and forms fiber grating string, and the head and the tail two ends of fiber grating string connect respectively communications optical cable and other fiber grating deep displacement sensor.