KR20080111235A - Bassett convergence measuring instrument of fiber bragg grating sensor and thereof measuring method - Google Patents

Abstract

A device and a method for measuring bassett convergence by using a fiber bragg grating sensor are provided to realize precise measurement without the influence of electromagnetic waves regardless of the running of subway trains. A device for measuring bassett convergence by using a fiber bragg grating sensor includes a main body(60) mounted to a subject to measure, a fixed element(21) fixed to a front surface of the main body, a rotation element(20) mounted in the main body with a distance from the fixed element horizontally, the rotation element being rotatable by a bearing, an optical fiber(11) adhered to an upper top surface of the fixed element and the rotation element horizontally in the tension state, fiber bragg grating sensor(10) mounted to the optical fiber between the fixed and rotation elements, and a weight(40) vertically mounted to the rotation element in connection with a lower part of the rotation element and a supporting die(41) of a predetermined length.

Description

Fault measuring device using optical fiber grating sensor and measuring method using same {BASSETT CONVERGENCE MEASURING INSTRUMENT OF FIBER BRAGG GRATING SENSOR AND THEREOF MEASURING METHOD}

1 is a view showing a first embodiment of an internal displacement measurement apparatus using an optical fiber grating sensor according to the present invention,

Figure 2 is a view showing a second embodiment of the hole displacement measuring apparatus using the optical fiber grating sensor according to the present invention,

3 is a left side view showing an example of the operation of FIG. 2;

4 is a view showing the appearance of the hole displacement measuring apparatus using the optical fiber grating sensor according to the present invention, it is a view showing that a level gauge is installed,

5 is a view showing a third embodiment of the internal displacement measurement device using an optical fiber grating sensor according to the present invention,

6 and 7 show another embodiment of FIG. 5;

8 is a view showing a fourth embodiment of an internal displacement measurement apparatus using an optical fiber grating sensor according to the present invention;

9 is a view showing another embodiment of FIG. 8;

10 is a view showing another embodiment of the internal displacement measurement device using an optical fiber grating sensor according to the present invention.

Explanation of symbols on the main parts of the drawings

10, 10a, 10b: optical fiber lattice sensor 11: optical fiber

12: optical fiber adhesion fixing part 13: optical terminal

20: rotating body 20a: shaft

21: Fixture 21b: Anti-rotation bolt

30: posture maintenance device 301: support

302 horizontal bar 40: weight

41: support 50: displacement control unit

50a: adjusting bolt 50b: body

60: main body 70: level

The present invention relates to a hole displacement measuring apparatus using an optical fiber grating sensor and a measuring method using the same, and more specifically, by measuring the deformation of the optical fiber grating sensor at the time of tilt or vibration using the optical fiber grating sensor for measuring the precise deformation, The present invention relates to a hole displacement measuring device using an optical fiber lattice sensor and a measuring method using the same, which can measure the hole displacement such as tilting and gravity acceleration of an object under measurement such as hole displacement of a bridge or tunnel.

In general, the tunnel in which the subway is operated may be deformed by the impact generated from the ground or the vibration and noise generated when the subway is operated. Therefore, it is necessary to periodically measure the hole displacement of the tunnel.

In other words, the measurement of the internal hole displacement of the tunnel is to determine the stability of the tunnel by measuring the behavior of the tunnel's inner cross-section, and mainly the gravity acceleration measurement due to the slope of the tunnel or the vibration of noise.

Conventionally, the hole resistance of the tunnel is measured using an electric resistance gauge, but the measurement accuracy is poor, especially when the subway is in operation, its value is unreliable due to the influence of electromagnetic waves, so real-time measurement is not possible. Measurement was possible.

However, recalling that the internal displacement of the tunnel is considerably physically affected by the speed and the load of the subway, it is a very big problem that it cannot be measured when the subway is in operation.

The present invention has been made to solve the above problems of the prior art, is installed in a subway tunnel, and can be measured at any time irrespective of the operation of the subway so that the measurement is not affected by electromagnetic waves at all, the optical fiber capable of more precise measurement The purpose of the present invention is to provide a hole displacement measuring apparatus using a grating sensor and a measuring method using the same.

The above object of the present invention, the main body is installed on the object to be measured; A posture maintaining device which is installed at the front of the main body and rotates in association with the inclination of the main body; A fixed body fixedly installed at one side of the posture maintaining device; A rotating body spaced apart from the fixed body and rotatably installed by a bearing coupling on the other side of the posture maintaining device; An optical fiber bonded horizontally to maintain a tension state on the upper outer surface of the fixed body and the rotating body; An optical fiber grating sensor installed on an optical fiber between the fixed body and the rotating body; And a weight installed in a vertical state connected to the lower part of the rotating body by a support of a predetermined length, and installed on an object to be measured to measure a deformation value of an angle due to deformation. It can be achieved by the hole displacement measuring device using a sensor.

In addition, the above object of the present invention, the main body is installed on the object to be measured; A fixed body installed to be fixed to the front surface of the main body; A rotating body spaced apart from the fixed body by a predetermined distance and installed in the main body to be rotatable by a bearing coupling; Upper and lower optical fibers connected to upper and lower outer surfaces of the fixed body and the rotating body and horizontally connected to maintain a tensioned state; An optical fiber lattice sensor installed on an upper optical fiber installed on an upper outer surface of the fixed body and the rotating body; And a weight installed in a vertical state connected to the lower part of the rotating body by a support of a predetermined length, and installed on an object to be measured to measure a deformation value of gravity acceleration due to deformation. It can be achieved by the hole displacement measuring device using a grating sensor.

The above object of the present invention, the main body is installed on the object to be measured; A fixed body installed to be fixed to the front surface of the main body; A rotating body spaced apart from the fixed body by a predetermined distance and installed in the main body to be rotatable by a bearing coupling; An optical fiber which is horizontally adhesively connected to the upper outer surface of the fixed body and the rotating body, and has optical terminals respectively installed at both ends thereof; An optical fiber grating sensor installed on an optical fiber between the fixed body and the rotating body; A measurement method using a hole displacement measuring device comprising a weight installed in a vertical state connected by a support of a lower portion and a predetermined length, the method comprising: measuring the wavelength displacement of the optical fiber grating sensor and setting it as a reference value; Installing the main body on an object to be measured such as a tunnel wall; Measuring the wavelength displacement value according to the tension and contraction of the optical fiber grating sensor by further rotating in conjunction with the inclination of the object to be measured by the ground change; It can be achieved by the method for measuring the pore displacement using the optical fiber grating sensor, characterized in that it comprises a four step of obtaining the angular displacement by substituting the wavelength displacement value measured in the three steps into the equation.

The above object of the present invention, the main body is installed on the object to be measured; A fixed body installed to be fixed to the front of the main body; A rotating body spaced apart from the fixed body by a predetermined distance and installed in the main body to be rotatable by a bearing coupling; Upper and lower optical fibers connected to the upper outer surface and the lower outer surface of the fixed body and the rotating body so as to be horizontally connected to each other to maintain a tensioned state, and optical terminals are respectively installed at both ends thereof; An optical fiber lattice sensor installed on an upper optical fiber installed on an upper outer surface of the fixed body and the rotating body; In the measuring method using a hole displacement measuring device consisting of a weight installed in a vertical state connected by the support of the lower portion and a predetermined length, the upper optical fiber is rotated by 90 ° counterclockwise by rotating the weight Contracting and allowing the lower optical fiber to be tensioned; Measuring the wavelength displacement of the optical fiber grating sensor in the first step and setting it as a reference value of the gravity acceleration 1G; Rotating the main body clockwise by rotating the main body 90 ° to further rotate the main body to the original position in the first step; Installing the main body on an object to be measured such as a tunnel wall surface; 5 steps of measuring the wavelength displacement value of the optical fiber grating sensor by additional vibration in conjunction with the left and right vibration of the object to be measured by the ground change; Obtaining a tension of the weight by substituting the wavelength displacement value measured in step 5 into the equation, and comparing the displacement with the reference value of step 3 to obtain the changed gravity acceleration; It can be achieved by the method of measuring the displacement resistance used.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing a first embodiment of the internal displacement measurement device using the optical fiber grating sensor according to the present invention, Figure 4 is a view showing the appearance of the internal displacement measurement device using the optical fiber grating sensor according to the present invention. , Which shows that a horizontal system is installed.

Referring to FIG. 1, the apparatus for measuring internal void displacement A1 using an optical fiber grating sensor according to a first embodiment of the present invention is installed on an object to be measured, such as a tunnel wall, to measure a deformation value of an angle due to deformation. A main body 60 installed on the object to be measured; A fixed body 21 fixedly installed on the front surface of the main body 60; A rotating body 20 spaced apart from the fixed body 21 by a predetermined distance and installed in the main body 60 to be rotatable by a bearing coupling; An optical fiber 11 attached to an upper outer surface of the fixing body 21 and horizontally attached to an upper outer surface of the rotating body 20 to maintain a tension state, and optical terminals 13 respectively provided at both ends thereof. )Wow; An optical fiber grating sensor 10 installed on an optical fiber between the fixed body 21 and the rotating body 20; It comprises a weight 40 is installed in a vertical state connected by a lower portion of the rotating body 20 and the support 301 of a predetermined length.

The main body 60 is formed in a rectangular plate shape or an enclosure having an accommodating portion therein, and as shown in FIG. 4, a horizontal system 70 and a vertical system 80 are provided outside.

The fixed body 21 or the rotating body 20 preferably uses a circular wheel, and the rotating body 20 is coupled to the shaft 20a formed in the main body 60 by a bearing to minimize frictional force.

The optical fiber grating sensor 10 may include fiber bragg grating; Also referred to as FBG), the refractive index of the core portion of the optical fiber is changed at regular intervals, and selectively reflects only light having a specific wavelength (Bragg wavelength: referred to as Bragg wavelength).

In addition, the optical fiber lattice sensor 10 has a unique wavelength value, and is known to have excellent physical properties such as being hardly affected by electromagnetic waves.

In general, while the optical fiber grating sensor 10 has a very high tensile force per unit area, since the diameter is very small as 125 μm, it can be easily broken due to external impact, and thus requires very delicate work when attached.

In addition, when installing the optical fiber grating sensor 10 to connect the outer peripheral surface of the fixed body 21 and the rotating body 20 is installed in a tensioned state to be pulled to have a proper tensile force to be able to measure a more accurate value.

Displacement adjusters 50 are provided on both sides of the weight 40 to stop the movement of the weight 40 to limit the amplitude of the weight 40 or to prevent breakage during transportation.

The displacement controller 50 is the body 50b spaced apart at a predetermined distance on both sides of the weight 40 and the adjustment bolt 50a screwed to the body 50b and the end to support the side of the weight 40 In this configuration, by tightening or releasing the adjusting bolt 50a, it is possible to limit the space in which the weight 40 can move.

The displacement controller 50 is also applied to all of the second to fourth embodiments (A2 to A4) of the present invention to be described later, hereinafter repeated description of the displacement controller 50 will be omitted.

Therefore, when the measured object to which the main body 60 is attached is inclined, the main body 60 also behaves inclined integrally with the measured object, and since the weight 40 faces the center of the earth, It will rotate in the reverse direction.

At this time, since the rotating body 20 connected by the weight 40 and the support 41 is rotated, the optical fiber 11 is tensioned or contracted, and the displacement of the optical fiber grating sensor 10 is sensed.

Therefore, since the magnitude of the rotational force generated by the weight 40 changes in proportion to the rotational angle of the main body 60, the optical fiber grid sensor 10 can detect the displacement and convert it into an angle.

In addition, by tightening or loosening the adjustment bolt 50a of the displacement control unit 50 installed on both sides of the weight 40, the amplitude of the weight 40 is limited.

Therefore, the durability of the optical fiber grating sensor 10 is prevented by preventing the occurrence of displacement of the weight 40 more than necessary, and when moving, the tightening bolt 50a is further tightened to bring the weight 40 into close contact with the weight 40. By fixing the to prevent damage to the optical fiber grating sensor 10.

The adjustment bolt 50a is preferably installed to enable the user to operate from the outside of the main body 60.

On the other hand, by installing a temperature compensation optical fiber lattice sensor (not shown) in the main body 60, by detecting the deformation of the main body 60 according to the temperature, by correcting the measured value, more accurate measurement is possible, as shown in Figure 4 As described above, the construction may be facilitated by installing the horizontal system 70 or the vertical system 80 on the X axis and the Y axis outside the main body 60.

2 is a view showing a second embodiment of the internal displacement measurement device using the optical fiber grating sensor according to the present invention, Figure 3 is a left side view showing an operation example of the FIG.

2 and 3, the internal displacement measurement device A2 using the optical fiber grating sensor according to the second exemplary embodiment of the present invention is installed on an object to be measured to measure a deformation value of an angle due to deformation. When the object to be measured is an inclined surface rather than a vertical surface, particularly an inclined shape in which the upper part protrudes forward, the rotating body 20 is naturally rotated in response to the inclination of the object to be measured so that the accurate operation of the rotating body can be performed. It is characterized in that the posture maintaining device 30 is installed so that the stationary body 21 and the weight 40 are always maintained perpendicular to the ground.

Looking at the configuration of the second embodiment, the main body 60 is installed on the object to be measured; Horizontal bars 302 connected to the plurality of supports 301 horizontally spaced apart on the front of the main body 60 and the plurality of supports 301, rotatably coupled to each support 301 by a bearing. Posture maintenance device 30 composed of; A fixed body 21 fixedly installed at one side of an inner surface of the horizontal bar 302; A rotating body 20 spaced apart from the fixed body 21 and rotatably installed on the other side of the inner surface of the horizontal bar 302 by bearing coupling; An optical fiber 11 attached to an upper outer surface of the fixing body 21, horizontally attached to an upper outer surface of the rotating body 20 to maintain a tension state, and optical terminals 11 each having optical terminals at both ends thereof; An optical fiber grating sensor 10 installed on the optical fiber 11 between the fixed body 21 and the rotating body 20; It is composed of a weight 40 installed in a vertical state connected by a lower portion of the rotating body 20 and a support 301 of a predetermined length.

The posture maintaining device 30 connects the plurality of brackets 301 horizontally spaced apart on the front of the main body 60 and the plurality of brackets 301, and is coupled to each support 301 by a bearing to rotate. It is composed of a horizontal bar (302) installed possibly.

Therefore, as shown in FIG. 3, when the main body 60 is installed on the measurement target inclined at a predetermined angle θ, the horizontal bar 302 of the posture maintaining device 30 is proportional to the angle θ. By rotating the rotating body 20, the fixed body 21 and the weight 40 can always be perpendicular to the ground, it is possible to prevent the rotating body 20 and the shaft 20a from being deflected to operate correctly As a result, the measurement can be made more precisely.

Also in the second embodiment of the present invention, the above-described displacement controller 50 is provided on both sides of the weight 40, the repeated description thereof will be omitted.

According to the second embodiment of the present invention, the rotating body 20 is installed on the inner side of one horizontal bar 30, the support 41 is fixed to the rotating body 20, the weight 40 Attach.

Then, the fixing body 21 is installed at a predetermined distance apart from the rotating body, and the optical fiber lattice sensor 10 is fixed to the rotating body and the outside of the fixing body.

At this time, by rotating the fixing body 21 to apply an appropriate tensile force to the optical fiber grid sensor 10, and then to prevent the rotation of the fixing body 21 by fastening the anti-rotation bolt (21b).

Therefore, when the object to be attached to which the main body 60 is attached rotates, the horizontal bar 30 coupled to the bracket 301 and the bearing 30a also rotates integrally with the object to be measured. Will rotate in the reverse direction.

At this time, by rotating the rotating body 20 in conjunction with the support 41 to apply a tensile force to the optical fiber grid sensor 10 to induce a change in the length of the optical fiber grid sensor 10.

That is, the magnitude of the rotational force generated by the weight 40 is proportionally changed in proportion to the rotation angle of the horizontal bar 30, and the optical fiber grid sensor 10 can detect the tension and convert the angle into an angle. .

Therefore, according to the second embodiment of the present invention, the horizontal bar 30 is coupled to the bracket 301 installed in the main body 60, the angle correction can be performed automatically by rotating in accordance with the inclination (θ) Accurate angle measurement is possible, and errors in construction can be corrected.

In addition, by installing the displacement adjusting unit 50 on both sides of the weight 40, as described above to prevent the degradation of the durability of the optical fiber grating sensor 10 due to the occurrence of displacement more than necessary, the adjustment bolt (50a) during movement By fixing the weight 40 to prevent damage to the optical fiber grating sensor 10 by the impact.

The measurement method using the hole displacement measuring apparatus using the optical fiber grating sensors according to the first and second embodiments of the present invention described above is as follows.

A first step (S1) of measuring the wavelength displacement of the optical fiber grating sensor 10 and setting it as a reference value; Installing the main body 60 on an object to be measured such as a tunnel wall surface (S2); A third step (S3) of measuring the wavelength displacement value according to the tension and contraction of the optical fiber grating sensor 10 by rotating the weight 40 in association with the inclination of the object to be measured by the ground change; It includes four steps (S4) to obtain the angular displacement by substituting the wavelength displacement value measured in the third step (S3) to the equation.

Here, the formula of step 4 (S4),

y = 0.6264 ㅇ x

y: angular displacement x: wavelength displacement

It is to obtain the angular displacement through the above [Equation 1].

1, the coefficient of [Equation 1] is the distance (L) from the center of the axis 20a to the center of gravity of the weight 40 and the center of the axis 20a and the contact point of the optical fiber 11 It varies according to the ratio of the distance l.

In addition, the coefficient of [Equation 1] varies depending on the weight of the weight 40.

5 is a view showing a third embodiment of the hole displacement measuring apparatus using the optical fiber grating sensor according to the present invention, Figures 6 and 7 is a view showing a modified embodiment of the FIG.

Referring to FIG. 5, the internal displacement measurement device A3 using the optical fiber grating sensor according to the third exemplary embodiment of the present invention is installed on an object to be measured to measure a change value G of a gravitational acceleration due to vibration. will be.

The configuration includes a main body 60 installed on the object to be measured; A fixed body 21 fixedly installed on the front surface of the main body 60; A rotating body 20 spaced apart from the fixed body 21 by a predetermined distance and installed in the main body 60 to be rotatable by a bearing coupling; The upper and lower optical fibers 111 are attached to the upper and lower outer surfaces of the fixing body 21 and the rotating body 20 so as to be horizontally connected to each other to maintain a tension state, and optical terminals 13 are installed at both ends thereof. 112; An optical fiber lattice sensor 10 installed on the upper optical fiber 11 installed on the upper outer surface of the fixed body 21 and the rotating body 20; It is composed of a weight 40 installed in a vertical state connected by a lower portion of the rotating body 20 and the support 41 of a predetermined length.

The upper and lower optical fibers 111 and 112 are horizontally connected to maintain the tensioned state by arranging the upper and lower outer surfaces of the fixture 21 and the rotating body 20 to surround the upper and lower outer surfaces.

In the third embodiment of the present invention, the fixed body 21 is installed on the front surface of the main body 60, and the rotating body 20 is coupled to the shaft 20a spaced apart from the main body 60, and the shaft 20a and The rotor 20 is coupled to the bearing as described above.

The measurement method using the hole displacement measuring apparatus using the optical fiber grating sensor according to the third embodiment of the present invention described above is as follows.

A first step (S1) of rotating the main body 60 in a counterclockwise direction so that the upper optical fiber 111 is contracted by the rotation of the weight 40 and the lower optical fiber 112 is tensioned; A second step (S2) of measuring the wavelength displacement of the optical fiber grating sensor 10 in the first step (S1) and setting it as a reference value of the gravity acceleration 1G; Step 3 (S3) to rotate the main body 60 in the clockwise direction to rotate 90 ° so that the weight 40 is in place; Installing the main body 60 on an object to be measured such as a tunnel wall surface (S4); Step 5 (S5) of measuring the wavelength displacement value of the optical fiber grating sensor 10 by vibrating the weight 40 in conjunction with the left and right vibration of the object to be measured by the ground change; Obtain the tension (g) of the weight (40) by substituting the wavelength displacement value measured in step 5 (S5) into the equation, and then change the gravitational acceleration (G), the displacement amount of which is compared with the reference value of step 3 (S3). Obtaining is made including six steps (S6).

Here, the formula of step 6 (S6),

y = 0.0136 ° x + 0.0009

y: Tension of the weight (g) x: Wavelength displacement

The gravitational acceleration G is obtained through Equation 2.

The coefficient of Equation 2 is a ratio of the distance L from the center of the shaft 20a to the center of gravity of the weight 40 and the distance L between the center of the shaft 20a and the contact point of the optical fiber 111. Will fluctuate accordingly.

In addition, the coefficient of [Equation 2] is varied according to the weight of the weight (40).

At this time, as shown in Figure 6, in the internal displacement measurement device using the optical fiber grating sensor according to the third embodiment of the present invention, by installing the optical fiber grating sensors (10a, 10b) in both the upper and lower optical fibers (111, 112), The tensile force and the compressive force applied to the upper and lower optical fibers 111 and 112 act symmetrically to enable precise measurement.

In addition, any one of the optical fiber grating sensors 111 and 112 may be used for temperature compensation.

On the other hand, as shown in Figure 7, the weight 40 is connected to the side of the rotating body 20 by a support 301 of a predetermined length may be installed in a horizontal state, so the weight 40 is horizontal By installing, there is an advantage of easy detection of vertical vibration.

8 is a view showing a fourth embodiment of the apparatus for measuring the internal displacement using the optical fiber grating sensor according to the present invention.

Referring to FIG. 8, the internal hole displacement measuring apparatus A4 using the optical fiber grating sensor according to the fourth exemplary embodiment of the present invention measures a strain value of gravity acceleration due to vibration, and is provided in a main body installed on an object to be measured. 60; A rotating body (20) installed to be rotatable by bearing coupling on a front surface of the main body (60); First and second fixed bodies 212 and 214 that are horizontally spaced apart at a predetermined distance from both sides of the rotating body 20 and fixedly installed; After being wound on the outer circumferential surface of the rotating body 20, one side is bonded to the first fixing body 212, the other side is bonded to the second fixing body 214 is connected horizontally to maintain a tension state, Optical fibers 11 each having optical terminals 13 provided at both ends thereof; An optical fiber lattice sensor 10 installed on the optical fiber 113 connecting the first fixing body 212 and the rotating body 20; It is composed of a weight 40 installed in a vertical state connected by a lower portion of the rotating body 20 and a support 301 of a predetermined length.

FIG. 9 is a view showing another embodiment of FIG. 8, and in the fourth embodiment of the present invention, an optical fiber is also provided on an optical fiber 114 connecting the second fixing body 21 and the rotating body 20. The grating sensor 10b is installed.

As described above, the internal displacement measurement devices A3 and A4 using the optical fiber grating sensors according to the third and fourth embodiments of the present invention are also used for the angle measurement as in the first and second embodiments A1 and A2. Of course it is possible.

10 is a view showing another embodiment of the internal displacement measurement device using an optical fiber grating sensor according to the present invention.

As shown in FIG. 10, in the hole displacement measuring apparatus using the optical fiber grating sensors according to the first to fourth embodiments of the present invention, the rotor 20 is spaced apart from the fixed body 21 by a predetermined distance. It is installed horizontally, is installed in the main body 60 so as to be rotatable by the bearing coupling, the weight member 20b is formed integrally to the lower portion to be eccentrically coupled.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it will be readily apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention, all such modifications and modifications being attached It is obvious that the claims belong to the claims.

As described above, the present invention completely overcomes the effects of electromagnetic waves, which are disadvantages of the conventional electric system, and enables to always measure tunnel displacement of a subway in operation, which has been impossible, and due to the excellent characteristics of an optical fiber grating sensor. The accuracy can also be increased, and up to 20 sensors can be connected in series with one strand of optical fiber, which requires much less space than conventional electric systems, and the optical fiber grating sensor itself has a unique wavelength value. There is an advantage that can measure the cumulative deformation compared to the initial value of.

Claims (1)

A main body installed on the object to be measured; A fixed body installed to be fixed to the front surface of the main body; A rotating body spaced apart from the fixed body by a predetermined distance and installed in the main body to be rotatable by a bearing coupling; An optical fiber adhesively connected horizontally to maintain a tension state on the upper outer surface of the fixed body and the rotating body; An optical fiber grating sensor installed on an optical fiber between the fixed body and the rotating body; It is made by including a weight installed in a vertical state connected by a support of a predetermined length and the lower portion of the rotating body, It is installed in the object to be measured to measure the displacement value of the angle due to the deformation, the internal displacement measurement device using the optical fiber grating sensor, characterized in that.

Images