KR101068463B1 - Optical fiber sensor using reflective grated panel - Google Patents

Abstract

The optical fiber sensor using the reflective grating board of this invention is a case; A reflective grating plate formed in a case in which a reflective surface made of a reflective material and a non-reflective surface made of a non-reflective material having a relatively lower reflectance than the reflective surface are arranged in a periodic arrangement and installed in a case; It is supported by the case so that its end is positioned in a direction perpendicular to the surface of the reflective grating, and consists of a single optical fiber serving as a light emitting part for irradiating light to the reflective grating and a light receiving part for receiving the reflected light reflected from the reflective grating. do. The present invention receives the amount of reflected light after irradiating light through an optical fiber that is not subjected to electromagnetic interference to the reflective grating formed periodically with a reflective surface and a non-reflective surface, and thus uses the amount of reflected light, such as displacement, pressure, vibration, or acceleration applied by an external force. It is possible to manufacture sensors that can measure a variety of things. In addition, the present invention can be applied to a wide range of fields, such as civil engineering structures, building structures, power plants or railway lines with poor electromagnetic environment at low cost by using stranded optical fiber and one reflective grating as long as it is not subjected to electromagnetic interference. It is possible to manufacture a sensor.

Optical fiber, grating, grating, reflection, acceleration, displacement meter, manometer, sensor

Description

Optical fiber sensor using reflective grated panel

The present invention relates to an optical fiber sensor, and more particularly, by irradiating light through an optical fiber that is not subjected to electromagnetic interference to a reflective grating on which a reflective surface and a non-reflective surface are periodically formed, and receiving and using the amount of light reflected therefrom, The present invention relates to an optical fiber sensor using a reflective grating that can measure various displacements, pressures, vibrations, or accelerations.

Large structures, such as bridges, large buildings, or power generation facilities, are so complex that accidents can occur for a variety of reasons. Such accidents can cause enormous loss of life and property, and can cause great inconvenience to industrial sites and daily life. Therefore, in order to maintain the safety of such a large structure, it is necessary to check regularly before a disaster occurs and repair or repair it accordingly.

However, in the case of power plants and railway tracks in which the electromagnetic environment is poor, the signal noise problem is serious when the number of sensors installed and the length of the wire connecting the sensors are too long to block the electromagnetic waves. Therefore, there is a problem in using the existing electronic-based sensor.

The optical fiber sensor is also a sensor of smart structure. These optical fiber sensors do not interfere with electromagnetic waves because they are measured using light. Therefore, it can be used even during the operation of the electromagnetic environment or the structure. In addition, the sensitivity is very excellent and real-time measurement of defects is possible. In addition, it is small in size and light in weight, so when applied to the structure, less weight concentration effect, the diameter is very small and flexible, so that the user can produce the desired size. In addition, it is resistant to environmental influences such as corrosion, which is directly related to sensor life, and has excellent temperature characteristics, so it can be used in a wide range of operating temperatures. There are advantages such as monitoring.

Due to these advantages, various studies have been conducted to measure physical quantities using optical fiber sensors. In addition, various studies have been conducted on the optical fiber sensor as a sensor for monitoring the health of the structure. However, in the case of an extrinsic fabry-perot interferometric (EFPI) sensor, an interference signal is used, so a microscopic gap must be made using a microscope, and signal processing is complicated because the interference signal does not come out as a sine wave. In addition, the fiber Bragg grating (FBG) sensor is uneconomical because the system is expensive to construct.

In the related art, there are techniques for measuring displacement, strain or acceleration using a grid pattern. This technique uses the moire fringe phenomenon that occurs when two grating patterns overlap each other. Thus, this technique requires two gratings. In addition, since this technique measures the displacement, strain, or acceleration using the transmitted signal, it is necessary to configure a pair of two optical fibers, each of which serves as a light emitting unit and a light receiving unit. Therefore, when fabricating a sensor, since the optical fiber lines extend to both sides, the structure is complicated.

Therefore, there is an urgent need for research and development of simple, economical and efficient sensors that can be applied in a wide range of fields such as civil engineering structures, building structures, power plants or railway tracks with poor electromagnetic environment.

Accordingly, the present invention has been made to solve the problems of the prior art as described above, the amount of light that is reflected after irradiating light through the optical fiber that does not receive electromagnetic interference to the reflective grating formed periodically with a reflective surface and a non-reflective surface By receiving and using the same, an object of the present invention is to provide an optical fiber sensor using a reflective grating plate capable of various measurements such as displacement, pressure, vibration or acceleration applied by an external force.

In addition, the present invention uses a strand of optical fiber and one reflective grating as long as it is not subjected to electromagnetic interference, so that it can be applied to a wide range of fields such as civil engineering structures, building structures, power plants or railway tracks with poor electromagnetic environment. Another object is to provide an optical fiber sensor using a grid.

The optical fiber sensor using the reflective grating board of this invention is a case; A reflective surface composed of a reflective material to form a reflective area, and a non-reflective surface composed of a non-reflective material having a relatively lower reflectance than the reflective surface to form a non-reflective area are formed in a lattice form periodically arranged in the case. One reflective grating installed; It is supported by the case so that its end is located in a direction perpendicular to the surface of the reflective grating, and includes a strand of optical fiber, each of which serves as a light emitting portion for irradiating light to the reflective grating and a light receiving portion for receiving the reflected light reflected from the reflective grating The width of the reflective surface and the width of the non-reflective surface are the same or smaller than the diameter of the light beam irradiated from the optical fiber.

The reflective grating of the present invention may have a reflective surface and a non-reflective surface each formed in a rectangular shape.

It is preferable that the end of the optical fiber of the present invention has a vertical cut surface shape, and at the end of the vertical cut surface of the optical fiber, it is more preferable to mount a collimator for producing parallel light to increase the amount of reflected light reflected by the optical fiber. Do.

In the optical fiber sensor for displacement measurement of the present invention, the optical fiber sensor configured as described above is used, but one side of the reflective grating is fixed to one side of the measurement target, and the reflective and non-reflective surfaces of the reflective grating are periodically oriented toward the moving direction of the measurement target. It is fixed so as to be arranged as, characterized in that for measuring the displacement of the measurement object.

The optical fiber sensor for vibration and acceleration measurement of the present invention, using the optical fiber sensor configured as described above, a single attenuator fixed to the lower inner side of the case, a single elastic member provided on the upper side of the single attenuator, It further includes a single mass body installed on the upper side, and the case is fixed to the measurement object, one side of the single-side mass of one side of the reflective grating so that the reflective surface and the non-reflective surface of the reflective grating periodically arranged in the direction of vibration and acceleration of the measurement object. It is characterized in that for measuring the vibration and acceleration of the measurement object.

The optical fiber sensor for pressure measurement of the present invention uses a fiber sensor configured as described above, but is fixed to the lower inner surface of the case and installed in a vertical direction, and a guide bar fixed to the lower inner surface of the case and installed in a vertical direction. It further comprises an elastomer installed on one side of the guide bar, the reflective grating is coupled to the guide bar so that the reflective grating slides along the guide bar, the reflective surface and the non-reflective surface of the reflective grating in the pressure direction applied to the reflective grating One side of the reflective grating plate is fixed to the upper part of the elastic member so as to be periodically arranged, and the pressure is measured.

The present invention receives the amount of reflected light after irradiating light through an optical fiber that is not subjected to electromagnetic interference to the reflective grating formed periodically with a reflective surface and a non-reflective surface, and thus uses the amount of reflected light, such as displacement, pressure, vibration, or acceleration applied by an external force. It is possible to manufacture sensors that can measure a variety of things.

In addition, the present invention can be applied to a wide range of fields, such as civil engineering structures, building structures, power plants or railway lines with poor electromagnetic environment at low cost by using stranded optical fiber and one reflective grating as long as it is not subjected to electromagnetic interference. It is possible to manufacture a sensor.

In addition, the present invention can mass-produce the reflective gratings from the MEMS process, and the optical system can be composed of a laser source and a photodetector, so that a cost-saving effect can be expected. It can increase.

In addition, the present invention can conveniently couple or fix the reflective grating to the measurement object, so that free measurement in the horizontal and / or vertical direction of the measurement object is possible.

First, the basic principle of the optical fiber sensor using the reflective grating board according to the present invention will be described.

1 is a block diagram of a reflective grating used in the present invention, Figure 2 is a block diagram showing the basic principle of the optical fiber sensor using a reflective grating according to the present invention, Figure 3 is a configuration relationship of the optical fiber sensor shown in FIG. 4 is a configuration diagram illustrating the signal form obtained through the optical fiber sensor shown in FIG. 3.

As shown in Figures 1 to 4, the reflective grating plate 100 of the present invention is a reflection surface 110 made of a reflective material to form a reflection area, and a non-reflective material consisting of a non-reflective area to form The reflective surfaces 120 are arranged periodically to form a grid. Here, the reflecting surface 110 means that the reflectance is higher than the non-reflective surface 120, including the complete reflection, but not complete reflection, the non-reflective surface 120 includes the complete reflection, even if not completely reflective 110) it means that the reflectance is lower than, it should be interpreted in a broad sense respectively.

In the reflective grating plate 100, the reflective surface 110 and the non-reflective surface 120 are each formed in a rectangular shape. That is, the reflective grating plate 100 has a structure in which the reflective surface 110 and the non-reflective surface 120 are repeatedly arranged with a predetermined period d (pitch). Here, the constant period d means the sum of the width d1 of the reflective surface 110 and the width d2 of the non-reflective surface 120. In addition, the reflective surface 110 and the non-reflective surface 120 have a straight line between the reflective surface 110 and the non-reflective surface 120 if the amount of reflected light varies according to the incident region of the light. It may be configured in a curved form, not in a form.

As shown in Figures 2 and 3, the optical fiber sensor using the reflective grating of the present invention irradiates light to the reflective grating 100 in a linear motion in a state where the optical fiber 200 is fixed, and then the reflective grating ( 100 is configured to receive and use the amount of light reflected by the reflected light. In this case, the reflective grating plate 100 is arranged such that the reflective surface 110 and the non-reflective surface 120 are periodically arranged in the linear movement direction thereof. The optical fiber 200 is disposed in a direction perpendicular to the surface of the reflective grating 100. Therefore, the reflective grating 100 moves in a direction perpendicular to the vertical cutting plane 210 of the end of the optical fiber 200, and the light irradiated through the vertical cutting plane 210 of the optical fiber 200 is reflected by the reflective grating 100. The light is modulated by the sum of the amounts of light and output as output light every predetermined period (d). At this time, the end of the vertical cutting surface 210 of the optical fiber 200 is preferably equipped with a collimator (collimator) for producing parallel light to increase the amount of reflected light reflected by the optical fiber.

Here, as the difference in reflectance between the reflective surface 110 and the non-reflective surface 120 increases, the interference signal decreases and the output signal has a larger amplitude, thereby improving resolution. At this time, the width d1 of the reflective surface 110 and the width d2 of the non-reflective surface 120 are the same as or smaller than the diameter of the light beam irradiated from the optical fiber 200 to obtain a periodic signal and to process the signal. . In other words, when using the reflecting grating 100 having the width d1 of the reflecting surface 110 and the width d2 of the non-reflecting surface 120 having the same size as the diameter of the light beam, the amplitude of the reflected signal is the most. Big. In addition, even though there is a ratio between the width d1 of the reflective surface 110 and the width d2 of the non-reflective surface 120 or the widths d1 and d2 are smaller than the diameter of the light beam, the sine wave signal appears, In the case of a light beam having a distribution, it is preferable to use a reflecting grating plate 100 having a reflecting surface 110 and a non-reflecting surface 120 having widths d1 and d2 of 40% or more of the light beam diameter. In this case, even if the ratio between the width d1 of the reflective surface 110 and the width d2 of the non-reflective surface 120 is 0.8 to 1.2, a sine wave signal can be obtained.

The present invention is a light source 220 transmitted through the optical fiber 200 using a laser diode (LD) or a light emitting diode (LED), etc., the reflective grating 100 through the vertical cutting surface 210 of the end of the optical fiber 200. Irradiate light. In this case, the light incident on the reflective surface 110, which is the reflective region of the reflective grating plate 100, is reflected and then transmitted to the optical fiber 200 through the vertical cutting surface 210 of the optical fiber 200. Then, the reflected light is input to the photo detector 240 in a path different from that when it is incident by the circulator 230 or coupler. Therefore, the output light can be detected.

At this time, even for the same displacement change, the width d1 of the reflective surface 110, the width d1 of the reflective surface 110, and the width d2 of the non-reflective surface 120 are each other as shown in FIG. 4. Output waveforms with different sensitivity are output. In other words, a triangular wave with a constant resolution may be generated in any section as shown in (b) of FIG. 4, a sine wave may be created as shown in (a) of FIG. 4, or a nonlinear function may be created. At this time, if a nonlinear function is obtained, it becomes difficult to predict the displacement from the received signal.

Therefore, in constructing the sensor using the reflective grating plate 100, it is important to meet the conditions for outputting the sine wave, but it is also necessary to design the pattern of the reflective grating plate 100 in consideration of the sensitivity of the sensor. In addition, when the displacement is measured by the change in the amount of light reflected using the reflective grating 100, the displacement size and speed of the measurement target, the response speed and the signal processing speed of the light quantity measuring system, etc. are considered. The elements must be traded off. The first is how fast the response of the signal appears according to the movement of the reflective grating 100, and the second is how precisely the movement of the reflective grating 100 can be measured.

In order to increase the reaction speed according to the movement of the reflective grating 100, the width d1 of the reflective surface 110 and the width d2 of the non-reflective surface 120 are reduced so that many cycles appear in the movement section, thereby providing special signal processing. It is to be able to see and judge the cycle. However, since this method reduces the amplitude, it is limited by the specification (resolution) of the photodetector 240 to measure when converting it to the magnitude of the voltage. On the other hand, when measuring the slowly changing displacement precisely, the width of the reflected light amount should be made as large as possible, so that the width d1 of the reflecting surface 110 and the width d2 of the non-reflecting surface 120 are set relatively large. Should be. Therefore, the reflective grating 100 must be designed in consideration of both of the above aspects of the measurement object.

The present invention uses only one reflective grating plate 100 and uses only a reflection signal instead of a light transmission signal, compared to a conventional optical fiber sensor using a moire phenomenon. At 200, the light emitting unit and the light receiving unit are configured to serve together. Therefore, the structure can be simplified when manufactured with a sensor. In addition, when designing the sensor head module based on the above principle, it is possible to exclude the interference of electromagnetic waves due to all the electrical / electronic devices, so that the optical fiber sensor of the present invention is required for the production of nuclear power, other power equipment or construction / Applicable to all civil structures. In addition, when applied to these various fields, the unique advantages of the optical fiber sensor can minimize the degradation of the reliability of the measurement results due to environmental noise. Therefore, if the system is configured according to the parameters to be measured based on the above-described basic principle, the sensor can be utilized as an optical fiber sensor.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of an optical fiber sensor using a reflective grating according to the present invention will be described in detail.

<First Embodiment>

5A and 5B are conceptual views illustrating a concept of measuring uniaxial and biaxial displacements of a measurement object using an optical fiber sensor using a reflective grating according to a first embodiment of the present invention.

As shown in FIG. 5A, the optical fiber sensor using the reflective grating plate of this embodiment irradiates light to the reflective grating plate 100 having a linear motion in a state where the optical fiber 200 is fixed, as described in the basic principle above. It is then configured to receive the amount of light reflected off the reflective grating plate 100. Here, one side of the reflective grating plate 100 is fixed to one side of the measurement object 500. In this case, the reflective grating plate 100 is fixed to the measurement object 500 such that the reflective surface 110 and the non-reflective surface 120 are periodically arranged in the linear movement direction of the measurement object 500. In addition, the optical fiber 200 is fixed to any fixture such that its cross section is disposed in a direction perpendicular to the surface of the reflective grating 100.

Therefore, when the measurement object 500 moves, the reflective grating 100 moves in a direction perpendicular to the cross section of the optical fiber 200, and the light irradiated through the end of the optical fiber 200 is reflected by the reflective grating 100. Since it is modulated by the sum and output as the output light every predetermined period (d), it is possible to detect the movement displacement of one axis of the measurement object 500.

And, if you want to measure the movement displacement with respect to the two axes of the measurement object 500 as shown in Figure 5b, by installing one more reflecting grating plate 100a and optical fiber 200a in the same concept as in Figure 5a, Detection of movement displacement with respect to two axes of 500 is possible. Therefore, in this embodiment, by installing the reflective grating and the optical fiber in the same concept as above, it is possible to detect the movement displacement with respect to the multi-axis of the measurement object.

Second Embodiment

Fig. 6 is a schematic diagram showing the configuration of the optical fiber sensor for displacement measurement using the reflective grating plate according to the second embodiment of the present invention.

As shown in FIG. 6, the optical fiber sensor 600 for displacement measurement using the reflective grating of this embodiment has a cylindrical case 610, a circular cylinder 630 disposed inside the cylindrical case 610, and one side thereof. A connecting bar 640 fixed to the circular cylinder 630 and the other side penetrating the lower portion of the cylindrical case 610 and fixed to one side of the measurement object, a fixing table 650 fixed to the upper end of the circular cylinder 630; One side of the fixing grid 650 is fixed to the fixing stand 650, and the cylindrical case 610 is installed through one side of the cross-section is installed in a direction perpendicular to the surface of the reflective grid 100 It consists of the optical fiber 200.

Here, the reflective grating plate 100 is fixed to the holder 650 such that the reflective surface 110 and the non-reflective surface 120 are periodically arranged in the linear movement direction of the measurement object. In addition, the optical fiber 200 is fixed to any fixture such that its cross section is disposed in a direction perpendicular to the surface of the reflective grating 100. The cylindrical case 610 and the circular cylinder 630 may be coated with a material such as a polymer having a low friction coefficient to reduce friction generated when the circular cylinder 630 moves up and down. In addition, a guide for shortening the length of the optical fiber 200 to prevent vibration of the optical fiber 200 due to external force, and guiding the optical fiber 200 around the hole of the cylindrical case 610 through which the optical fiber 200 penetrates. It is preferable to provide the member 660. At this time, the guide member 660 is fixed around the hole of the cylindrical case 610 with an adhesive such as epoxy.

Therefore, when the measurement object is moved, the reflective grating 100 moves in a direction perpendicular to the cross section of the optical fiber 200, and the light irradiated through the end of the optical fiber 200 is the sum of the amount of light reflected by the reflective grating 100. Since it is modulated and output as a sine wave having a certain period, it is possible to detect the movement displacement about one axis of the measurement object.

Third Embodiment

7 is a schematic diagram showing the configuration of the optical fiber sensor for vibration and acceleration measurement using a reflective grating plate according to a third embodiment of the present invention.

As shown in FIG. 7, the optical fiber sensor 700 for displacement measurement using the reflective grating of this embodiment includes a case 710, a single attenuator 720 fixed to a lower inner surface of the case 710, and a single The single elastic body 730 is installed on the upper portion of the damper 720, the single mass body 740 is installed on the upper portion of the single elastic body 730, and the configuration as described above fixed to one side of the single mass body 740 It consists of a reflective grating plate 100, and the optical fiber 200 which is installed to penetrate through one side of the case 710, the cross section is installed in a direction perpendicular to the surface of the reflective grating plate 100.

Here, the reflective grating 100 is fixed to the single mass 740 such that the reflective surface 110 and the non-reflective surface 120 are periodically arranged in the vibration and / or acceleration direction of the measurement object. In addition, the optical fiber 200 is fixed to any fixture such that its cross section is disposed in a direction perpendicular to the surface of the reflective grating 100. And, it is preferable to provide a guide member 750 for guiding the optical fiber 200 around the hole of the case 710 through which the optical fiber 200 passes. At this time, the guide member 750 is fixed around the hole of the case 710 with an adhesive such as epoxy.

In measuring the acceleration of the measurement object using the optical fiber sensor 700 of this embodiment configured as described above, the relative displacement between the reflection grating 200 and the case 710 from the sum of the amount of light reflected by the reflection grating 200 This relative displacement can be used to measure acceleration. In this case, since the reflective grating 200 is coupled to the single mass body 740 and acts integrally, the final external acceleration is measured by using a linear relationship between the relative displacement of the single mass body 740 and the acceleration applied from the outside from the vibration point of view. can do.

<Fourth Embodiment>

8 is a schematic diagram showing the configuration of the optical fiber sensor for pressure measurement using a reflective grating according to a fourth embodiment of the present invention.

As shown in FIG. 8, the optical fiber sensor 800 for pressure measurement using the reflective grating board of this embodiment is fixed to a case 810 and a lower inner side surface of the case 810, and is provided with a guide bar installed vertically. 820 and the case 810 are fixed to the lower inner surface of the case 810 is installed in the vertical direction is installed, the elastic bar 830 is installed on one side of the guide bar 820, the elastic bar 830 is fixed to the top of the guide bar A reflective grating 100 configured as described above capable of linear movement along the 820 and an optical fiber which is installed through one side of the case 810 and whose cross section is installed in a direction perpendicular to the surface of the reflective grating 100. 200 and a pressure adding plate 840 installed on the reflective grating plate 100 to allow external pressure to be added to the reflective grating plate 100.

Here, the reflective grating plate 100 is fixed to the elastic member 830 such that the reflective surface 110 and the non-reflective surface 120 are periodically arranged in a direction in which pressure is applied. In addition, the optical fiber 200 is fixed to any fixture such that its cross section is disposed in a direction perpendicular to the surface of the reflective grating 100. In addition, the guide bar 820 may be provided with a groove so that the slide movement is possible in a state where a portion of the reflective grating 100 is fitted, and a ball bearing may be installed to reduce the friction inside the groove so that the slide movement may be more smoothly performed. .

In addition, the pressure adding plate 840 is connected to the reflective grating plate 100 with its circumference supported on the upper end of the case 810, and is composed of a thin plate. And, it is preferable to provide a guide member 850 for guiding the optical fiber 200 around the hole of the case 810 through which the optical fiber 200 passes. At this time, the guide member 850 is fixed around the hole of the case 810 with an adhesive such as epoxy.

In measuring the pressure using the optical fiber sensor 800 of this embodiment configured as described above, the reflective grating 100 moves as the pressure is applied, and thus the pressure is measured using the displacement information of the guide bar 820. It can be measured.

The technical details of the optical fiber sensor using the reflective grating plate of the present invention have been described above with the accompanying drawings, but this is only illustrative of the best embodiment of the present invention and is not intended to limit the present invention.

In addition, it is obvious that any person skilled in the art can make various modifications and imitations within the scope of the appended claims without departing from the scope of the technical idea of the present invention.

1 is a block diagram of a reflective grating used in the present invention,

2 is a block diagram showing the basic principle of the optical fiber sensor using a reflective grating according to the present invention,

3 is a configuration diagram showing in more detail the configuration of the optical fiber sensor shown in FIG.

4 is a graph showing a signal form acquired through the optical fiber sensor shown in FIG.

5A and 5B are conceptual views illustrating a concept of measuring uniaxial and biaxial displacements of a measurement object using an optical fiber sensor using a reflective grating according to a first embodiment of the present invention.

6 is a schematic diagram showing the configuration of the optical fiber sensor for displacement measurement using the reflective grating plate according to the second embodiment of the present invention;

7 is a schematic diagram showing the configuration of the optical fiber sensor for vibration and acceleration measurement using a reflective grating according to a third embodiment of the present invention,

8 is a schematic diagram showing the configuration of the optical fiber sensor for pressure measurement using a reflective grating according to a fourth embodiment of the present invention.

  ♠ Explanation of symbols on the main parts of the drawing ♠

100: reflective grating 110: reflective surface

120: non-reflective surface 200: optical fiber

210: vertical cutting plane

Claims (7)

A case; The reflective surface is composed of a reflective material to form a reflective region, and the non-reflective surface composed of a non-reflective material having a relatively lower reflectance than the reflective surface to form a non-reflective region is configured in the form of a grid arranged periodically, One reflective grating installed in the case; A strand which is supported by the case so that its end is positioned in a direction perpendicular to the surface of the reflective grating, and serves as a light emitting part for irradiating light to the reflective grating and a light receiving part for receiving the reflected light reflected from the reflective grating; Fiber optics, And the width of the reflective surface and the width of the non-reflective surface are the same or smaller than the diameter of the light beam irradiated from the optical fiber. The method according to claim 1, The reflective grating is an optical fiber sensor using a reflective grating, characterized in that each of the reflective surface and the non-reflective surface is formed in a rectangular shape. The method according to claim 2, An end portion of the optical fiber has a vertical cut surface form, the optical fiber sensor using a reflective grating. The method of claim 3, The optical fiber sensor using a reflective grating plate, characterized in that the collimator for producing parallel light to further increase the amount of reflected light reflected by the optical fiber at the end of the vertical cut surface of the optical fiber. Using the optical fiber sensor according to any one of claims 1 to 4, One side of the reflective grating is fixed to one side of the measurement object, and the reflective surface and the non-reflective surface of the reflective grating is fixed so as to be periodically arranged in the moving direction of the measurement object, thereby measuring the displacement of the measurement object. Optical fiber sensor for displacement measurement using a reflective grating. Using the optical fiber sensor according to any one of claims 1 to 4, And a single damper fixed to the lower inner side of the case, a single elastic member installed on the upper side of the single damper, and a single mass body installed on the single elastic side, Fixing the case to the measurement object, by coupling one side of the reflective grating to one side of the single mass so that the reflective surface and the non-reflective surface of the reflective grating is periodically arranged in the direction of vibration and acceleration of the measurement object, Vibration and acceleration measurement optical fiber sensor using a reflective grating, characterized in that for measuring the vibration and acceleration of the measurement object. Using the optical fiber sensor according to any one of claims 1 to 4, The guide bar is fixed to the lower inner surface of the case and installed in a vertical direction, and installed in the vertical direction, the guide bar is fixed to the lower inner surface of the case and installed in a vertical direction further comprises an elastic member installed on one side of the guide bar, The reflective grating is coupled to the guide bar to allow the reflective grating to slide along the guide bar, and the reflection such that the reflective surface and the non-reflective surface of the reflective grating are periodically arranged in a pressure direction applied to the reflective grating. A pressure measuring optical fiber sensor using a reflective grating, characterized in that one side of the grating is fixed to the upper part of the elastic member to measure the pressure.

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