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CN-120629631-B - Micro-surface external speed sensor for detecting micro-vibration and acceleration detection method

CN120629631BCN 120629631 BCN120629631 BCN 120629631BCN-120629631-B

Abstract

The invention relates to the technical field of vibration detection, and provides a micro-surface external speed sensor for detecting micro-vibration and an acceleration detection method. The acceleration sensor comprises an optical fiber and an elastic component which is oppositely arranged at one end of the optical fiber, wherein the elastic component comprises a frame, a central mass block, four edge mass blocks, four first cantilever beams and four second cantilever beams, the edge mass blocks are distributed around the central mass block in a surrounding mode and are rotationally symmetrical at 90 degrees, one end of a first long side of each edge mass block is connected with one vertex of the central mass block through the first cantilever beams, and the other end of the first long side of each edge mass block is connected with the inner side of the frame through the second cantilever beams. According to the invention, the edge mass block, the first cantilever beam and the second cantilever beam are arranged, so that a U-shaped connecting structure is formed, and the sensitivity and the shock resistance of the U-shaped connecting structure are improved.

Inventors

  • LU PING
  • LIU CHAOYUE
  • ZHAI JIE
  • ZHANG JIANGSHAN

Assignees

  • 华中科技大学

Dates

Publication Date
20260512
Application Date
20250606

Claims (7)

  1. 1. The micro out-of-plane acceleration sensor for detecting micro vibration is characterized by comprising an optical fiber (1) and an elastic component (2) which is oppositely arranged at one end of the optical fiber (1); The elastic component (2) comprises a frame (21), a central mass block (22), four edge mass blocks (23), four first cantilever beams (24) and four second cantilever beams (25) which are etched on one block material; the edge mass blocks (23) are circumferentially distributed around the center mass block (22) and are rotationally symmetrical at 90 degrees; One end of a first long side (231) of each edge mass block (23) is connected with one vertex of the central mass block (22) through a first cantilever beam (24), and the other end of the first long side (231) of each edge mass block (23) is connected with the inner side of the frame (21) through a second cantilever beam (25), wherein the first long side (231) is a long side, close to the frame (21), of the edge mass block (23); the first cantilever beam (24) comprises a first cantilever (241) and a second cantilever (242) which are perpendicular to each other, the first cantilever (241) is located on an extension line of one side of the central mass block (22) and is connected with the vertex of the first side, the second cantilever (242) is located on an extension line of the first long side (231) of the edge mass block (23) and is connected with the vertex of the first long side (231), the second cantilever beam (25) comprises a third cantilever (251) and a fourth cantilever (252) which are perpendicular to each other, the third cantilever (251) is located on an extension line of the first long side (231) of the edge mass block (23) and is connected with the vertex of the first long side (231), the fourth cantilever (252) is parallel to the short side of the edge mass block (23) and is connected with the inner side of the frame (21), the first short side (232) of each edge mass block (23) is connected with the other short side (232) of the first side (23) which is close to the first side (23), and the second cantilever (25) is close to the first side (231).
  2. 2. The micro out-of-plane acceleration sensor for micro vibration detection according to claim 1, characterized in, that the frame (21) is further provided with four connection parts (211) extending from each inner top corner position of the frame (21), wherein the connection parts (211) extend towards the opposite inner top corner to approach the edge mass (23) perpendicular to the extending direction thereof, such that the ends of the connection parts (211) are connected with the corresponding second cantilever beams (25); The other end of the first long side (231) of each edge mass block (23) is connected with the inner side of the frame (21) through a second cantilever beam (25), and the other end of the first long side (231) is connected with the tail end of the connecting part (211) through the second cantilever beam (25).
  3. 3. The micro out-of-plane acceleration sensor of claim 1, characterized in, that the bulk material is beryllium copper.
  4. 4. The micro out-of-plane acceleration sensor for detecting micro vibrations according to claim 1, characterized by further comprising a groove base (3); the bottom of the groove base (3) is provided with a through hole (31), and the frame (21) of the elastic component (2) is arranged at the top of the groove base (3); The optical fiber (1) passes through the through hole (31) to be aligned with the center of the elastic member (2).
  5. 5. An acceleration detection method, characterized in that the acceleration in the direction perpendicular to the elastic member (2) is measured using the micro-surface applied velocity sensor for detecting micro-vibration according to any one of claims 1 to 4, comprising: collecting interference light signals of an optical fiber (1) in the micro out-of-plane acceleration sensor, wherein the spectrum function of the interference light signals ; Spectral function of the interference light signal Fourier transforming and extracting peaks of its spatial spectrum Wherein Spatial frequency points that are peaks; According to the peak value Calculating to obtain the phase angle Wherein, the method comprises the steps of, , ; According to phase angle Correspondence with acceleration Calculating to obtain acceleration; Wherein, the In order to interfere with the free spectral range of the optical signal, A is acceleration, lambda is spectral center wavelength, Representing the extracted real part, Representing the extracted imaginary part, Representing complex modulus, n is the refractive index of the medium in the FP cavity, And Is a preset coefficient.
  6. 6. The micro out-of-plane acceleration sensor for detecting micro vibration is characterized by comprising a first sensor, a second sensor and a third sensor, wherein the first sensor, the second sensor and the third sensor are all the micro out-of-plane acceleration sensor for detecting micro vibration according to any one of claims 1-4; the first elastic component (51), the second elastic component (52) and the third elastic component (53) are perpendicular to each other, and the cavity lengths of the first sensor, the second sensor and the third sensor are different; the first elastic component (51) is an elastic component of the first sensor, the second elastic component (52) is an elastic component of the second sensor, and the third elastic component (53) is an elastic component of the third sensor.
  7. 7. An acceleration detection method, characterized in that acceleration in three vertical directions is measured using the micro out-of-plane acceleration sensor for detecting micro vibrations according to claim 6, the method comprising: collecting a composite signal formed by overlapping three interference light signals in the micro out-of-plane acceleration sensor ; For the composite signal Fourier transforming and extracting the ith peak of the spatial spectrum ; According to the ith peak value Calculating to obtain the phase angle of the ith interference light signal in the composite signal Wherein, the method comprises the steps of, , ; According to the phase angle of the ith interference light signal Correspondence with acceleration in the i-th direction Calculating to obtain the acceleration in the ith direction; Wherein, the For the free spectral range of the ith interference optical signal, For the resonant frequency of the sensor, Acceleration in the i-th direction, lambda is the spectral center wavelength, Representing the extracted real part, Representing the extracted imaginary part, Representing complex modulus, i is an integer, i is greater than 0 and less than or equal to 3, n is the refractive index of the medium in the FP cavity, 、 、 And Is a preset coefficient.

Description

Micro-surface external speed sensor for detecting micro-vibration and acceleration detection method Technical Field The invention relates to the technical field of vibration detection, in particular to a micro-surface external speed sensor for detecting micro-vibration and an acceleration detection method. Background Acceleration measurement plays a vital role in the modern industry and technology. In the aerospace field, the vibration acceleration of key parts of an aircraft is monitored, the structural health state can be estimated in real time, mechanical faults are prevented, flight safety is guaranteed, in intelligent manufacturing, a high-precision acceleration sensor can capture micro abnormal vibration of equipment such as a machine tool and a robot, predictive maintenance is achieved, production efficiency is improved, and the method is applied to the field of new energy automobiles. With diversification and complication of use environments, acceleration sensors are evolving towards miniaturization and high sensitivity so as to meet the increasingly complex engineering monitoring requirements. Compared with an electrical acceleration sensor, the optical acceleration sensor body is small in size, light in weight, high in sensitivity, electromagnetic interference resistant, low in laying cost, capable of realizing remote signal transmission, easy for large-scale networking multiplexing, and therefore capable of being applied to severe environmental conditions on a large scale. In the aspect of acceleration transduction of the optical fiber acceleration sensor at present, the elastic column structure, the elastic disc and the optical fiber direct connection type structure are various, but are limited by a processing technology and an optical path structure in size, particularly a sensor processed by metal machining, the miniaturization requirement of the sensor is difficult to meet, the cantilever Liang Zhiliang block structure is compact, two-dimensional plane-like distribution is easy to form, and the cantilever Liang Zhiliang block structure is integrated on a substrate through a silicon micro-processing technology, and has the advantages of small size and light weight, but some cantilever beam mass block structures in the prior art often adopt four-beam inertial mass beam type sensitive structures, namely the four-beam inertial mass beam type sensitive structures comprise four beams and mass blocks, one side of the mass block close to a frame is directly connected with the frame through a beam, and the structure is poor in impact resistance, easy to damage and unfavorable for application in actual severe environments. In view of this, overcoming the drawbacks of the prior art is a problem to be solved in the art. Disclosure of Invention The invention aims to solve the technical problem of providing a micro out-of-plane acceleration sensor for detecting micro vibration, so as to solve the problem of poor impact resistance of an acceleration sensor in the prior art. The invention adopts the following technical scheme: In a first aspect, the present invention provides a micro out-of-plane acceleration sensor for detecting micro vibration, comprising an optical fiber 1 and an elastic component 2 oppositely arranged at one end of the optical fiber 1; the elastic component 2 comprises a frame 21, a central mass block 22, four edge mass blocks 23, four first cantilever beams 24 and four second cantilever beams 25 which are etched on a block material; the edge mass blocks 23 are distributed around the center mass block 22 in a surrounding manner and are rotationally symmetrical at 90 degrees; One end of the first long side 231 of each edge mass 23 is connected with one vertex of the center mass 22 through a first cantilever beam 24, and the other end of the first long side 231 of each edge mass 23 is connected with the inner side of the frame 21 through a second cantilever beam 25, wherein the first long side 231 is the long side of the edge mass 23 close to the frame 21. Preferably, the frame 21 is further provided with four connecting portions 211 extending from respective inner vertex angles of the frame 21, wherein the connecting portions 211 extend toward opposite inner vertex angles to be close to the edge mass block 23 perpendicular to the extending direction thereof, so that the tail ends of the connecting portions 211 are connected with corresponding second cantilever beams 25; The other end of the first long side 231 of each edge mass 23 is connected to the inner side of the frame 21 through the second cantilever beam 25, which is shown that the other end of the first long side 231 is connected to the end of the connecting portion 211 through the second cantilever beam 25. Preferably, the first cantilever beam 24 includes a first cantilever 241 and a second cantilever 242 perpendicular to each other; the first cantilever 241 is positioned on the extension line of one side of the center mass 22 a