Fiber grating two-dimensional acceleration sensor, control method and application

Abstract

The application belongs to the technical field of fiber grating sensors, and discloses a fiber grating two-dimensional acceleration sensor, a control method and application, wherein a vertical acceleration measurement module and a horizontal acceleration measurement module are mounted on the inner side of a shell; the vertical acceleration measurement module comprises a vertical displacement detection unit and an acceleration measurement unit, the horizontal acceleration measurement module comprises a swing beam and a first elastic block, the upper end of the swing beam is connected with the shell through a cantilever beam, the lower part of the swing beam is provided with a tooth structure, the upper part of the first elastic block is provided with a tooth structure, the lower end of the swing beam and the upper end of the elastic block are mutually engaged, and the side surface of the first elastic block is connected with a second fiber grating for horizontal acceleration wavelength measurement. The application overcomes the deficiency of traditional one-dimensional acceleration sensors that can only measure acceleration in a single direction, eliminates the influence of temperature change on two-dimensional acceleration measurement, greatly reduces measurement error, and can realize the measurement of multiple physical parameters such as temperature and acceleration.

Description

Technical Field

[0001] This invention belongs to the field of fiber optic grating sensor technology, and particularly relates to a two-dimensional fiber optic grating accelerometer based on a toothed structure for force transmission, its control method, and its application. Background Technology

[0002] Currently, fiber Bragg gratings have received widespread attention and research due to their advantages such as resistance to electromagnetic interference, small size, wide dynamic range, and corrosion resistance. Fiber Bragg grating sensors are widely used in earthquake monitoring and vibration testing and analysis of railway bridges and dams. Acceleration is one of the important parameters for measuring vibration. Fiber Bragg grating accelerometers utilize the wavelength modulation principle of gratings, that is, using external perturbation vibrations to change the grating pitch, which is then converted into a corresponding wavelength change. The magnitude of acceleration is measured by detecting the change in wavelength.

[0003] Traditional fiber Bragg grating accelerometers can only measure vibrations in a single direction. In CN111174897A, Jia Zhenan et al. proposed a two-dimensional fiber Bragg grating vibration sensor. However, it can only measure vibrations in two directions separately when they occur individually. In practical engineering, vibrations in two directions often occur simultaneously. Therefore, this invention proposes a two-dimensional accelerometer based on a toothed structure force-transmitting fiber Bragg grating that can measure the vibration state in two different directions in real time. This can effectively solve the above problems and be better applied to practical engineering measurements.

[0004] Based on the above analysis, the problems and defects of the existing technology are as follows: traditional fiber optic grating accelerometers can only measure vibrations in a single direction or can only measure vibrations in two directions separately when they occur individually, and cannot be applied to situations where vibrations in two directions occur simultaneously. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a fiber Bragg grating two-dimensional accelerometer, a control method, and its application.

[0006] This invention is implemented as follows: a fiber Bragg grating two-dimensional accelerometer includes:

[0007] shell;

[0008] The inner side of the housing is equipped with a vertical acceleration measurement module for measuring acceleration in the vertical direction and a lateral acceleration measurement module for measuring acceleration in the horizontal direction.

[0009] The vertical acceleration measurement module includes a vertical displacement detection unit and an acceleration measurement unit. The vertical displacement detection unit is used to detect vertical displacement using a mass block, and the acceleration measurement unit is used to measure the displacement acceleration transmitted by the mass block using a second elastic block and a fiber optic grating.

[0010] The lateral acceleration measurement module includes a swing beam and a first elastic block. The upper end of the swing beam is connected to the housing via a cantilever beam. The lower part of the swing beam has a toothed structure. The first elastic block is fixed inside the lower part of the housing. The upper part of the first elastic block has a toothed structure. The lower end of the swing beam and the upper end of the elastic block mesh with each other. A second fiber grating for measuring the lateral acceleration wavelength is connected to the side of the first elastic block.

[0011] Furthermore, the upper end of the mass block of the vertical acceleration measurement module is connected to the top of the outer shell through a high-strength spring. The mass block has symmetrically distributed toothed structures on both sides. The second elastic block has two symmetrically fixed inside the outer shell. The outer side of the second elastic block has toothed structures. The left side of the mass block meshes with the left side of the second elastic block. The right side of the mass block is connected to the right side of the second elastic block through a gear. The gear is installed at the lower end of the outer side of the cantilever beam.

[0012] Furthermore, a boss is fixed to the bottom of the inner side of the outer shell, and the high-strength spring and the upper end of the cantilever beam are both fixedly connected to the lower end of the boss.

[0013] Furthermore, the upper end of the second elastic element on the left is connected to the first fiber optic grating, and the upper end of the second elastic element on the right is connected to the third fiber optic grating.

[0014] Furthermore, the high-strength spring 4 is composed of two high-strength springs connected in parallel with a spring constant of K / 2.

[0015] Furthermore, the lateral acceleration measurement module also includes a temperature-compensated fiber Bragg grating, which is connected to the left side of the first elastic block to eliminate the influence of temperature changes on the two-dimensional acceleration measurement.

[0016] Furthermore, the top of the outer shell has symmetrically arranged slots at the left and right ends. The slots are hollow cylindrical structures used as attachment points for fixing optical fibers at the fiber outlet. After the optical fiber is led out, it is sealed with glue. The lower right corner of the inner side of the outer shell has a protrusion that serves as a two-point glue fixing attachment point for the fiber grating.

[0017] Furthermore, the fiber grating is initially in a straightened state.

[0018] Another object of the present invention is to provide a control method for a fiber Bragg grating two-dimensional accelerometer, the control method comprising:

[0019] Step 1: The fiber Bragg grating two-dimensional accelerometer is vertically fixed on the object being measured. Under the action of vibration, for the measurement of vertical acceleration, the tension of the high-strength spring is no longer balanced with the gravity of the mass block. The first elastic block and the gear on the left are subjected to the opposite force given by the mass block, and the second elastic block on the left undergoes axial deformation, causing a change in the wavelength of the first fiber Bragg grating.

[0020] Step 2: The rotation of the gear transmits a vertical force to the second elastic block on the right, causing a slight vertical deformation of the second elastic block. The axial deformation of the second elastic block on the right is transmitted to the third fiber optic grating, causing a change in the wavelength of the third fiber optic grating. The magnitude of the vertical acceleration is measured by detecting the changes in the wavelengths of the first and third fiber optic gratings.

[0021] Step 3: For the measurement of lateral acceleration, when the oscillating beam vibrates laterally, it tends to oscillate under the action of inertial force. The horizontal force is transmitted to the first elastic block through the toothed structure, causing the first elastic block to deform in the horizontal direction. This causes the wavelength of the temperature-compensated fiber grating and the second fiber grating to change. The magnitude of the horizontal acceleration of the measured object is obtained by detecting the change in the wavelength of the second fiber grating and combining it with the temperature-compensated fiber grating.

[0022] Based on the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by this invention are as follows:

[0023] 1. A double-spring device is adopted. While ensuring the total stiffness is K, two springs with a stiffness of K / 2 are connected in parallel. The vertical stiffness remains unchanged, while the lateral stiffness is increased. This greatly reduces the interference of lateral vibration when measuring vertical acceleration, thus ensuring the accuracy of unidirectional measurements.

[0024] 2. The fiber optic grating is fixed at both ends with adhesive, while the grating portion in the middle is suspended, reducing the difficulty of sensor packaging. This effectively avoids and eliminates chirp, and also increases the sensor's sensitivity.

[0025] 3. Measurement accuracy is adjustable. The rotation of the gear causes axial deformation of the elastic block, which in turn causes a reverse drift in the center wavelength of the right fiber grating. Changing the gear radius directly affects the magnitude of the axial strain of the elastic block caused by a unit displacement change in the mass block. Therefore, the monitoring accuracy and sensitivity of the sensor can be adjusted by changing the gear radius to meet the needs of different situations.

[0026] 4. This invention provides a two-dimensional fiber optic grating accelerometer. Using this structure, acceleration in two directions can be measured in real time, overcoming the limitation of one-dimensional accelerometers that can only measure acceleration in a single direction.

[0027] 5. Most fiber optic accelerometer sensors are only used to detect vibration and cannot simultaneously measure temperature and vibration. However, this invention independently sets up a fiber optic grating for measuring temperature, which eliminates the influence of temperature changes on two-dimensional acceleration measurement, solves the problem of sensitivity to temperature and strain crossover, reduces measurement error, and enables the measurement of multiple physical parameters such as temperature and acceleration.

[0028] 6. At the sensor's "zero point" position, the spring's gravity and the mass block's gravity are balanced. The mass block exerts no vertical force on the elastic block. The free end rack of the swing beam contacts the top of the elastic block without deformation. This avoids the situation where the elastic element is constantly in a deformed state, which can lead to easy creep and greatly improves the accuracy of the measurement results.

[0029] 7. This invention is designed with two fiber optic exit holes. The pigtail of the No. 1 fiber optic grating is connected to the fiber optic grating demodulator through the exit hole. The pigtail of the No. 4 fiber optic grating can be connected in series with other sensors through the other exit hole to realize multi-point distributed acceleration detection of the object under test. At the same time, it can also be connected in series with other physical parameter fiber optic grating sensors to realize multi-point multi-physical parameter distributed detection of the object under test.

[0030] 8. High sensitivity. The gear mechanism causes the elastic blocks on both sides to deform in opposite directions. Initially, the fiber gratings on both sides are in a pre-stretched state. Under vibration, the force on one fiber grating increases, leading to an increase in its wavelength, while the force on the other fiber grating decreases, leading to a decrease in its wavelength. This creates a differential effect. The wavelength shift is calculated by subtracting the reflected wavelengths of the two fiber gratings. By adding the wavelength changes together, the sensor's sensitivity is greatly improved.

[0031] 9. The operating frequency band is adjustable. For vertical acceleration, changing the size of the mass block and the spring stiffness can alter the sensor's natural frequency and corresponding operating frequency band. For lateral acceleration, the sensor's natural frequency can be adjusted by changing the length and thickness of the swing beam, thus meeting different measurement requirements.

[0032] 10. This invention provides a two-dimensional accelerometer based on a toothed fiber optic grating, which overcomes the shortcomings of traditional one-dimensional accelerometers that can only measure acceleration in a single direction, eliminates the influence of temperature changes on two-dimensional acceleration measurement, solves the problem of sensitivity to temperature and strain crossover, greatly reduces measurement error, and can realize the measurement of multiple physical parameters such as temperature and acceleration. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the fiber optic grating two-dimensional accelerometer provided in Embodiment 1 of the present invention;

[0034] Figure 2This is a schematic diagram of the swing beam provided in Embodiment 1 of the present invention;

[0035] Figure 3 This is a schematic diagram of the cantilever beam provided in Embodiment 1 of the present invention;

[0036] Figure 4 This is a schematic diagram of the assembly of the cantilever beam and the swing beam provided in Embodiment 1 of the present invention;

[0037] Figure 5 This is a schematic diagram of the structure of the one-dimensional accelerometer provided in Embodiment 2 of the present invention;

[0038] Figure 6 This is a connection principle diagram for implementing distributed monitoring of multiple points and multiple physical parameters provided in Embodiment 3 of the present invention;

[0039] In the diagram: 1. Slot; 2. First fiber Bragg grating; 3. Housing; 4. High-strength spring; 5. Mass block; 6. Temperature-compensated fiber Bragg grating; 7. First elastic block; 8. Second fiber Bragg grating; 9. Swinging beam; 10. Second elastic block; 11. Gear; 12. Cantilever beam; 13. Third fiber Bragg grating; 14. Boss; 15. Protrusion. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0041] To enable those skilled in the art to fully understand how the present invention is specifically implemented, this section provides an explanatory description of the embodiments that expand upon the technical solutions of the claims.

[0042] Example 1:

[0043] like Figures 1 to 4 As shown, the fiber Bragg grating two-dimensional accelerometer provided in this embodiment of the invention includes a slot 1, a first fiber Bragg grating 2, a housing 3, a high-strength spring 4, a mass block 5, a temperature-compensated fiber Bragg grating 6, a first elastic block 7, a second fiber Bragg grating 8, a swing beam 9, a second elastic block 10, a gear 11, a cantilever beam 12, a third fiber Bragg grating 13, a boss 14, and a protrusion 15. Fiber Bragg gratings 2, 6, 8, and 13 are connected in series on a single optical fiber.

[0044] Card slot 1: made of metal, cylindrical, hollow inside. It is symmetrically arranged at the top left and right ends of the outer shell 3. It is used to fix the attachment point of the optical fiber with glue, and also serves as a fiber exit hole. After the optical fiber is exited, it is sealed with glue.

[0045] First fiber grating 1: The fiber grating is pre-stretched and glued at two points. FBG1 is suspended and used for vertical acceleration measurement.

[0046] Shell 3: Made of metal, with a closed interior, serving as the sensor housing to encapsulate the sensor. It has a protrusion 15 in the lower right corner and two pre-drilled slots 1 on the top left and right sides.

[0047] High-strength stiff spring 4: It consists of two high-strength stiff springs connected in parallel with a spring constant of K / 2, and the upper part is fixedly welded to the boss 14.

[0048] Mass block 5: A mass block with a mass of M, featuring symmetrically distributed toothed structures on both sides. It is welded together with spring 4.

[0049] Temperature-compensated fiber Bragg grating 6: It adopts two-point adhesive bonding, with FBG2 suspended. It is only affected by the ambient temperature of the object being measured and is mainly used for temperature compensation.

[0050] First elastic block 7: It is fixed to the lower part of the inner shell 3 with bolts, has a certain elasticity, and has a toothed structure on the upper part that meshes with the teeth of the swing beam 9.

[0051] Second fiber grating 8: The fiber grating is pre-stretched and bonded at two points. FBG3 is suspended and used for lateral acceleration measurement.

[0052] Swinging beam 9: Made of metal, with a toothed structure at the bottom that meshes with the teeth of the elastic block. It is fixed to the cantilever beam by bolts.

[0053] First elastic block 10: It has a certain elasticity and is symmetrically fixed to both sides of the inside of the shell with screws. One side has a toothed structure that meshes with the gear or elastic block holding structure. The toothed structure is used to transmit force and control the axial deformation of the elastic block.

[0054] Gear 11: Fixed to the cantilever beam 11 by bolts, made of metal, with built-in bearings, and rotatable. It is tangent to the mass block 5 and the elastic block 10 on the left and right sides respectively, and meshes with the toothed structures of the elastic block 10 and the mass block 5.

[0055] Cantilever beam 12: made of metal, with screws at the top and through holes at the bottom, and fixed to the boss 14.

[0056] The third fiber grating 13: The fiber grating is pre-stretched and glued at two points. The FBG4 is suspended and used for vertical acceleration measurement.

[0057] Boss 14: The upper four corners are provided with threaded holes, which are fixed to the outer shell 3 with screws. The metal material is used to fix the cantilever beam 12 and the high-strength spring 4.

[0058] Protrusion 15: Metal material, fixed on the outer shell 3, serving as the attachment point for two-point adhesive fixation of the fiber optic grating.

[0059] The fiber optic grating two-dimensional accelerometer provided in this embodiment of the invention is vertically fixed to the object being measured and generates acceleration in different directions as the object vibrates. Under the action of vibration, for the measurement of vertical acceleration, the tension of the high-strength spring 4 is no longer balanced with the gravity of the mass block 5, and is subjected to the vertical force of the left first elastic block 10 and the gear 11. At the same time, since the toothed structure on the side of the mass block 5 and the teeth of the gear 11 are all meshed with each other, the left first elastic block 10 and the gear 11 are also subjected to the opposite force from the mass block 5. The toothed structure of the left first elastic block 10 plays a role in transmitting force, controlling the axial deformation of the first elastic block 10, thereby causing a change in the wavelength of the first fiber optic grating 2. The teeth on the left side of gear 11 rotate under the force of the toothed structure on the right side of mass block 5, thus transmitting a vertical force to the first elastic block 10 on the right side. This causes a slight vertical deformation in the first elastic block 10, and the axial deformation of the first elastic block 10 is transmitted to the third fiber grating 13, causing a change in the wavelength of the third fiber grating 13. The magnitude of the vertical acceleration is measured by detecting the change in wavelength. Due to the switching action of the gear, the deformation directions of the left and right elastic blocks are opposite. Initially, the left and right fiber gratings are in a pre-stretched state. Under vibration, the force on one fiber grating increases, leading to an increase in the wavelength of the fiber grating, while the force on the other fiber grating decreases, leading to a decrease in the wavelength of the fiber grating. This creates a differential effect. The wavelength changes are added together, greatly improving the sensitivity of the sensor. The wavelength drift is obtained by subtracting the reflected wavelengths of the two fiber gratings. Analysis shows that the greater the acceleration of the measured object, the greater the difference in wavelength drift. Changing the radius of gear 11 directly affects the rotation angle of gear 11 caused by the unit displacement change of mass block 5, thus affecting the axial strain of the first elastic block 10 on the right. The larger the rotation angle of gear 11, the greater the deformation of the first elastic block 10 on the right. Through the conversion action of gear 11, the deformation of the first elastic block 10 increases, and the wavelength change of the third fiber grating 13 increases, achieving high sensitivity with a relatively light mass block. The strain is amplified by the transmission of gear 11, increasing sensitivity. Therefore, the monitoring accuracy and sensitivity of the sensor can be adjusted by changing the radius of gear 11 to meet the needs of different situations. Since the wavelength changes of the fiber gratings on both sides are consistent under the influence of temperature, the wavelength drift can be obtained by subtracting the reflected wavelengths of the two fiber gratings, which can eliminate the corresponding interference and achieve the effect of temperature self-compensation. At the same time, changing the mass of mass block 5 and the spring stiffness changes the natural frequency and corresponding operating frequency band of the sensor.

[0060] For measuring lateral acceleration, when the lateral vibration occurs, the swing beam 9 tends to swing under the action of inertial force. The horizontal force is transmitted to the second elastic block 7 through the toothed structure, causing the second elastic block 7 to deform horizontally. This causes a change in the wavelength of the second fiber optic grating 8. The magnitude of the horizontal acceleration of the measured object is obtained by detecting the change in wavelength and combining it with the temperature-compensated fiber optic grating 6. In actual design and fabrication of the swing beam, the natural frequency of the sensor can be adjusted by changing the length and thickness of the swing beam 9, thereby meeting different measurement requirements.

[0061] Example 2:

[0062] The ability to resist lateral interference is of paramount importance for one-dimensional accelerometers, such as... Figure 5 As shown, this embodiment of the invention, after removing the swing beam and the bottom elastic block, can be used for one-dimensional acceleration measurement. First, the mass block is jammed by the gears and elastic block, restricting its lateral movement. Second, to reduce the impact of the spring's lateral movement on the mass block, the number of springs can be increased. While maintaining the vertical stiffness, the spring constant of a single spring is reduced, increasing the lateral stiffness and greatly improving the accuracy of unidirectional acceleration measurement. Simultaneously, the temperature-compensated fiber grating 6 and the second fiber grating 8 are removed. The consistent wavelength changes caused by temperature effects on the first fiber grating 2 and the third fiber grating 13 eliminate corresponding interference, achieving a temperature self-compensation effect.

[0063] Example 3: As Figure 6 As shown, the embodiment of the present invention is designed with two fiber exit holes. The pigtail of the fourth fiber grating is connected to the fiber grating demodulator through the fiber exit hole. The pigtail of the first fiber grating can be connected in series with other sensors through the other fiber exit hole to realize multi-point distributed acceleration detection of the object under test. At the same time, it can also be connected in series with other physical parameter fiber grating sensors to realize multi-point multi-physical parameter distributed monitoring of the object under test.

[0064] To demonstrate the inventiveness and technical value of the technical solution of this invention, this section provides specific product or related technology application examples of the technical solution claimed.

[0065] A vibration testing and analysis system, wherein the vibration testing and analysis system is equipped with the aforementioned fiber optic grating two-dimensional accelerometer.

[0066] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0067] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A fiber Bragg grating two-dimensional accelerometer, characterized in that, The fiber optic grating two-dimensional accelerometer includes: shell; The inner side of the housing is equipped with a vertical acceleration measurement module for measuring acceleration in the vertical direction and a lateral acceleration measurement module for measuring acceleration in the horizontal direction. The vertical acceleration measurement module includes a vertical displacement detection unit and an acceleration measurement unit. The vertical displacement detection unit is used to detect vertical displacement using a mass block, and the acceleration measurement unit is used to measure the displacement acceleration transmitted by the mass block using a second elastic block and a fiber optic grating. The lateral acceleration measurement module includes a swing beam and a first elastic block. The upper end of the swing beam is connected to the shell through a cantilever beam. The lower part of the swing beam has a toothed structure. The first elastic block is fixed inside the lower part of the shell. The upper part of the first elastic block has a toothed structure. The lower end of the swing beam and the upper end of the elastic block mesh with each other. A second fiber grating for measuring the lateral acceleration wavelength is connected to the side of the first elastic block. The upper end of the mass block of the vertical acceleration measurement module is connected to the top of the outer shell through a high-strength spring. The mass block has symmetrically distributed toothed structures on both sides. The second elastic block has two symmetrically fixed inside the outer shell. The outer side of the second elastic block has toothed structures. The left side of the mass block meshes with the left side of the second elastic block. The right side of the mass block is connected to the right side of the second elastic block through a gear. The gear is installed at the lower end of the outer side of the cantilever beam. A boss is fixed to the bottom of the inner side of the outer shell, and the high-strength spring and the upper end of the cantilever beam are both fixedly connected to the lower end of the boss.

2. The fiber optic grating two-dimensional accelerometer as described in claim 1, characterized in that, The upper end of the second elastic element on the left is connected to the first fiber optic grating, and the upper end of the second elastic element on the right is connected to the third fiber optic grating.

3. The fiber optic grating two-dimensional accelerometer sensor as described in claim 1, characterized in that, The high-strength spring is composed of two high-strength springs connected in parallel with a spring constant of K / 2.

4. The fiber optic grating two-dimensional accelerometer sensor as described in claim 1, characterized in that, The lateral acceleration measurement module also includes a temperature-compensated fiber Bragg grating, which is connected to the left side of the first elastic block to eliminate the influence of temperature changes on the two-dimensional acceleration measurement.

5. The fiber optic grating two-dimensional accelerometer sensor as described in claim 1, characterized in that, The top of the outer casing has symmetrical slots arranged at the left and right ends. The slots are hollow cylindrical structures used as attachment points for fixing optical fibers at the fiber outlet. After the optical fiber is led out, it is sealed with glue. The lower right corner of the inner side of the outer casing has a protrusion that serves as a two-point glue fixing attachment point for the fiber optic grating.

6. The fiber optic grating two-dimensional accelerometer as described in claim 1, characterized in that, The fiber grating is initially in a straightened state.

7. A control method for implementing the fiber optic grating two-dimensional accelerometer according to any one of claims 1 to 6, characterized in that, The control method for the fiber Bragg grating two-dimensional accelerometer includes: Step 1: The fiber Bragg grating two-dimensional accelerometer is vertically fixed on the object being measured. Under the action of vibration, for the measurement of vertical acceleration, the tension of the high-strength spring is no longer balanced with the gravity of the mass block. The first elastic block and the gear on the left are subjected to the opposite force given by the mass block, and the second elastic block on the left undergoes axial deformation, causing a change in the wavelength of the first fiber Bragg grating. Step 2: The rotation of the gear transmits a vertical force to the second elastic block on the right, causing a slight vertical deformation of the second elastic block. The axial deformation of the second elastic block on the right is transmitted to the third fiber optic grating, causing a change in the wavelength of the third fiber optic grating. The magnitude of the vertical acceleration is measured by detecting the changes in the wavelengths of the first and third fiber optic gratings. Step 3: For the measurement of lateral acceleration, when the oscillating beam vibrates laterally, it tends to oscillate under the action of inertial force. The horizontal force is transmitted to the first elastic block through the toothed structure, causing the first elastic block to deform in the horizontal direction. This causes the wavelength of the temperature-compensated fiber grating and the second fiber grating to change. The magnitude of the horizontal acceleration of the measured object is obtained by detecting the change in the wavelength of the second fiber grating and combining it with the temperature-compensated fiber grating.

8. A vibration testing and analysis system, characterized in that, The vibration testing and analysis system is equipped with a fiber optic grating two-dimensional accelerometer as described in any one of claims 1 to 6.

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