Bionic cantilever beam sensor and recognition system for vibration frequency measurement

Abstract

The invention relates to the technical field of vibration frequency measurement, in particular to a bionic cantilever beam sensor for vibration frequency measurement and an identification system. The balancing weight is arranged in the shell body; the top end of the main cantilever beam is connected with the balancing weight, the tail end of the main cantilever beam is provided with a zygopophysis, and the zygopophysis is movably connected into the shell; and the plurality of secondary cantilever beam structures are circumferentially and uniformly distributed on the side surface of the main cantilever beam. Based on the bionic design of a Johnson organ of aedes aegypti, through the synergistic effect of an array formed by the main cantilever beam and the multiple secondary cantilever beam structures, high-sensitivity and wide-frequency-domain detection of the vibration frequency is achieved, and the sensor is suitable for accurate monitoring in a complex vibration environment.

Description

Technical Field

[0001] This invention belongs to the field of vibration frequency measurement technology, and particularly relates to a biomimetic cantilever beam sensor and identification system for vibration frequency measurement. Background Technology

[0002] In recent years, vibration frequency detection has become increasingly important in fields such as industrial monitoring, structural health diagnosis, and aerospace. Traditional vibration sensors, especially single-beam structures, exhibit weak responses and poor signal-to-noise ratios in the low-frequency range, making them unsuitable for low-frequency vibration monitoring. A single beam will deflect under both lateral and longitudinal excitation, leading to crosstalk between vibration signals from multiple directions. To eliminate coupling, existing solutions often employ multiple orthogonally arranged independent cantilever beams; however, this significantly increases the overall sensor size, contradicting the miniaturization trend of MEMS systems.

[0003] Microcantilever beam structures have been widely used in microelectromechanical systems (MEMS) sensors due to their high sensitivity and miniaturization. However, most current cantilever beam sensors focus on static or quasi-static deformation detection, while research on cantilever beam sensors for dynamic vibration frequency identification is limited. Although some improved schemes can enhance sensitivity, they still cannot achieve efficient identification of multi-frequency vibrations and rely on complex sensor arrays, resulting in low system integration and increased costs. Summary of the Invention

[0004] In view of this, the present invention aims to provide a biomimetic cantilever beam sensor and identification system for vibration frequency measurement, in order to overcome the shortcomings of the prior art.

[0005] To achieve the above objectives, the technical solution created by this invention is implemented as follows: In a first aspect, a biomimetic cantilever beam sensor for measuring vibration frequency includes: case; A counterweight, wherein the counterweight is disposed within the housing; The main cantilever beam is disposed within the housing. The top end of the main cantilever beam is connected to the counterweight, and the end end is provided with an articular protrusion, which is movably connected within the housing. The secondary cantilever beam structure comprises multiple secondary cantilever beam structures evenly distributed circumferentially on the side surface of the main cantilever beam.

[0006] Furthermore, the articular process is clearance-fitted with the housing.

[0007] Furthermore, the secondary cantilever beam structure comprises multiple secondary cantilever beams with varying length gradients and connecting parts, with one end of each secondary cantilever beam fixed to the connecting part; and one end of the connecting part fixed to the main cantilever beam.

[0008] Furthermore, the multiple secondary cantilever beams with varying length gradients are evenly spaced on the connecting portion.

[0009] Furthermore, the secondary cantilever beams near the connection between the connecting portion and the main cantilever beam are arranged in order of increasing length.

[0010] Furthermore, the connecting part has a fan-shaped structure.

[0011] Furthermore, the counterweight is made of tungsten alloy or platinum alloy and is mechanically fixed to the main cantilever beam by means of threads or riveting.

[0012] Furthermore, the inner wall of the housing is provided with a limiting part and reinforcing ribs.

[0013] Secondly, a vibration frequency identification system includes: The aforementioned biomimetic cantilever beam sensor; Strain gauges are installed at the fixed end of the secondary cantilever beam; The controller is communicatively connected to the strain gauge, and performs differential amplification, RMS amplitude calculation, resonance determination, and outputs the main frequency signal for multiple strain signals. Additional equipment, connected to the controller, is used to display, record, or utilize the main frequency signal and to power the system.

[0014] Furthermore, the additional equipment is an energy recovery circuit that recovers the mechanical energy generated by the vibration of the secondary cantilever beam, the main cantilever beam, and the counterweight through piezoelectric or electromagnetic means, and supplies power to the controller and strain gauges.

[0015] Compared with the prior art, the present invention can achieve the following beneficial effects: This invention discloses a biomimetic cantilever beam sensor and recognition system for vibration frequency measurement. Through the synergistic effect of the main cantilever beam and secondary cantilever beam structure array, it achieves high sensitivity and wide frequency domain detection of vibration frequencies, making it suitable for precise monitoring in complex vibration environments. The circumferentially distributed secondary cantilever beam structure forms a symmetrical "multi-directional filter," exhibiting a spatially weighted response to vibrations in different directions. Combined with articular processes and counterweights, it effectively suppresses axial crosstalk, broadens the effective operating frequency band, and improves the quality factor of the resonance peak. Attached Figure Description

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 A schematic diagram of a biomimetic cantilever beam sensor structure for vibration frequency measurement as described in an embodiment of the present invention; Figure 2 A schematic diagram of the main cantilever beam of a biomimetic cantilever beam sensor for measuring vibration frequency, as described in an embodiment of the present invention. Figure 3 A schematic diagram of a pair of secondary cantilever beams in a biomimetic cantilever beam sensor for measuring vibration frequency, as described in an embodiment of the present invention. Figure 4 A schematic diagram of the internal structure of the Johnston organ of the Aedes aegypti mosquito, as described in an embodiment of the present invention; Figure 5 This is a schematic diagram of the housing of a biomimetic cantilever beam sensor for measuring vibration frequency, as described in an embodiment of the present invention.

[0017] In the diagram: 1. Counterweight, 2. Main cantilever beam, 21. Articular process, 3. Shell, 31. Limiting part, 32. Reinforcing rib, 33. Elliptical cavity, 4. Secondary cantilever beam structure, 41. Secondary cantilever beam, 42. Connecting part, 5. Base. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and do not constitute a limitation thereof. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the invention. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the invention are not shown or described in the specification. This is to avoid obscuring the core parts of the invention with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0019] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined to form various implementations. Furthermore, the order of the steps or actions in the method description can be changed or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various orders in the specification and drawings are merely for the clear description of a particular embodiment and do not imply a mandatory order, unless otherwise stated that a particular order must be followed.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this 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 on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] In related technologies, satellite ground vibration detection is a crucial step in ensuring satellite reliability, requiring the simulation of the complex vibration environment of rocket engines and the reentry phase before launch. Traditional sensors, such as piezoelectric accelerometers and MEMS, suffer from drawbacks such as poor low-frequency response, weak anti-interference capabilities, and insufficient frequency band coverage. To address at least one of the aforementioned technical problems in related technologies, this invention provides a biomimetic cantilever beam sensor and identification system for vibration frequency measurement. Figure 1 A schematic diagram of a biomimetic cantilever beam sensor for measuring vibration frequency is provided in an embodiment of the present invention; including: Housing 3; In this embodiment, fluororubber is selected as the base material, and 316L stainless steel wire is embedded as the spiral skeleton; Housing 3 is installed on the device under test via base 5; Counterweight 1, wherein the counterweight 1 is disposed within the housing 3; The main cantilever beam 2 is disposed within the housing 3. In this embodiment, the top end of the main cantilever beam 2 is mechanically fixed to the counterweight block 1 by means of threads or riveting, and the end is provided with an articular protrusion 21, such as... Figure 2As shown, the articular process 21 is movably connected to the housing 1 and is clearance-fitted with the housing 3; Secondary cantilever beam structure 4, a plurality of secondary cantilever beam structures 4 are evenly distributed around the side surface of the main cantilever beam 2.

[0023] In some embodiments, the secondary cantilever beam structure 4 comprises multiple secondary cantilever beams 41 with varying length gradients and connecting portions 42, such as... Figure 3 As shown, one end of the secondary cantilever beam 41 with varying length gradient is fixed to the connecting part 42; one end of the connecting part 42 is fixed to the main cantilever beam 2. The plurality of secondary cantilever beams 41 with varying length gradients are evenly spaced on the connecting part 42. The secondary cantilever beams 41 near the connection between the connecting part 42 and the main cantilever beam 2 are arranged in ascending order of length. The design principle of the secondary cantilever beam structure 4 of this invention is derived from biomimetic reference to the Johnston's Organ (JO) of the Aedes aegypti mosquito, such as... Figure 4 As shown. The Aedes aegypti mosquito is renowned as one of the most sensitive micro-vibration sensors in nature. The synergistic mechanism of its antennae and Johnston organs has been demonstrated to produce an ultrasensitive response to nanoscale vibrations in airflow fields. The distributed topology of over 30,000 neurons within the JO has been shown to enable broadband vibration frequency sensing through mechano-electrical signal conversion.

[0024] To simulate the spatial distribution and dynamic response characteristics of neurons in JO, in some embodiments, at least one layer of secondary cantilever beam structures 4 is provided on the main cantilever beam 2, with at least four secondary cantilever beam structures 4 evenly distributed around the circumference of each layer; for example... Figure 2 As shown, two layers of secondary cantilever beam structures 4 are provided on the main cantilever beam 2, with four secondary cantilever beam structures 4 in each layer, pointing in four directions respectively. Each secondary cantilever beam structure 4 includes 15 secondary cantilever beams 41 with varying length gradients, and the connecting part 42 is a fan-shaped structure.

[0025] When the device under test is subjected to an impact, the vibration is transmitted to the housing 3 through the base 5. For example... Figure 5 As shown, the elliptical cavity 33 at the bottom of the shell 3 drives the joint protrusion 21 of the main cantilever beam 2 to vibrate. The limiting part 31 at the top of the shell 3 prevents the main cantilever beam 2 from deflecting too much and suppresses the vibration amplitude of the main cantilever beam 2. Because the limiting part 31 is closer to the free end of the main cantilever beam 2, the vibration amplitude of the free end is larger. The reinforcing rib 32 is located in the middle of the shell 3. It is used to prevent the main cantilever beam 2 from compressing the fluororubber at the bottom of the shell 3 when it deflects, which would cause local stress concentration in the shell 3. At the same time, it disperses stress and delays local deformation of the shell 3.

[0026] Due to the effect of the counterweight 1, the main cantilever beam 2 only generates radial vibration. The gap between the elliptical cavity 33 and the articular process 21 of the main cantilever beam 2, and the counterweight 1, ensure the vibration direction of the main cantilever beam 2 and suppress axial interference.

[0027] Vibration is transmitted from the main cantilever beam 2 to the secondary cantilever beam 41. The vibration at the root of the main cantilever beam 2 drives the synchronous vibration of eight sets of secondary cantilever beam structures 4. The secondary cantilever beams 41 in each set of secondary cantilever beam structures 4 have different lengths, so that the natural frequency distribution of the secondary cantilever beams 41 of different lengths covers the target frequency band. When the input vibration frequency is close to the natural frequency of a certain secondary cantilever beam 41, the amplitude of that secondary cantilever beam 41 is significantly larger than that of the other secondary cantilever beams 41. Among them, the short secondary cantilever beams 41 achieve high-frequency resonance, the medium and long secondary cantilever beams 41 achieve mid-frequency resonance, and the long secondary cantilever beams 41 achieve low-frequency resonance.

[0028] The resonant frequency of the secondary cantilever beam 41 is related to its geometry and material properties. For a uniform secondary cantilever beam 41, its nth natural frequency can be expressed as:

[0029] in These are constants related to the vibration mode, E is the Young's modulus of the secondary cantilever beam 41 material, and I is the moment of inertia of the secondary cantilever beam 41 section. The secondary cantilever beam has a material density of 41. The cross-sectional area of ​​the secondary cantilever beam is 41. It is the length of the secondary cantilever beam 41.

[0030] Secondly, embodiments of the present invention provide a vibration frequency identification system, comprising: The aforementioned biomimetic cantilever beam sensor.

[0031] Strain gauges are installed at the fixed end of the secondary cantilever beam 41 to measure the bending deformation of the secondary cantilever beam 41 and form an independent sensing channel; the strain signal amplitude of the resonant secondary cantilever beam 41 is significantly different from that of the non-resonant secondary cantilever beam 41.

[0032] The controller, communicatively connected to the strain gauges, performs differential amplification, RMS amplitude calculation, resonance determination, and outputs the main frequency signal for multiple strain signals. It ensures time alignment of data from each sensing channel by controlling synchronous sampling of multiple ADCs. When there is no vibration input, the static offset voltage of each channel is recorded to eliminate zero-point drift. Digital bandpass filtering is applied to the original signal to suppress low-frequency noise and high-frequency interference. When there is vibration input, the root mean square (RMS) voltage of the vibration signal from each sensing channel is calculated, reflecting the vibration energy of each secondary cantilever beam 41. Intra-group differential processing is performed on the signals of the secondary cantilever beam 41 within the same secondary cantilever beam structure group to further highlight the response of the resonant secondary cantilever beam 41.

[0033] The root mean square formula is:

[0034] in, This represents the original voltage value of the vibration signal output by a sensing channel, acquired at the i-th sampling point, where N represents the total number of sampling points. This represents the root mean square voltage of the vibration signal output by a sensing channel.

[0035] like Figure 2 As shown, the amplitudes of the same-numbered secondary cantilever beams 41 in the eight groups of secondary cantilever beam structures 4 (such as all #7 beams) are compared. If a certain numbered beam exhibits the largest amplitude in all four groups (such as the amplitude of #7 beam being greater than that of #6 and #8 beams), then #7 beam is determined to be the carrier of the resonant main frequency. Before leaving the factory, the natural frequency of each secondary cantilever beam 41 is calibrated through a frequency sweep experiment. The real-time lookup table logic is as follows: if the amplitude of #7 beam is the largest in all sensing channels, the pre-stored mapping table is directly called, the corresponding frequency value is output, and it is transmitted to the host computer through the digital interface.

[0036] The controller executes the following algorithm: Vibration signals are obtained by synchronously sampling the sensing channels of each strain gauge; Digital bandpass filtering is performed on each channel signal to remove common-mode noise; Calculate the RMS value of the filtered signal, and determine the one with the largest RMS value as the resonant beam of the secondary cantilever beam 41. The natural frequency corresponding to the resonant beam is output as the current dominant vibration frequency according to the pre-stored mapping table.

[0037] An auxiliary device, connected to the controller, is used to display, record, or utilize the main frequency signal and to power the system. This auxiliary device is an energy recovery circuit that recovers the mechanical energy generated by the vibration of the secondary cantilever beam 41, the main cantilever beam 2, and the counterweight 1 using piezoelectric or electromagnetic methods, and supplies power to the controller and strain gauges.

[0038] Thirdly, embodiments of the present invention provide a method for fabricating a biomimetic cantilever beam sensor for vibration frequency measurement as described above, comprising: The main cantilever beam 2 and the secondary cantilever beam 41 are prepared using one or more materials, including polyurethane acrylate or metal. The resonant frequencies of each order of the secondary cantilever beam 41 of the secondary cantilever beam structure 4 were obtained through finite element simulation and calculation. The main cantilever beam 2 and the secondary cantilever beam structure 4 are printed using 3D integrated printing, and the strain gauge installation interface of the secondary cantilever beam 41 is reserved. The counterweight is made of high-density metal, such as tungsten alloy or platinum alloy, and is mechanically fixed to the top of the main cantilever beam 2. Fluororubber was selected as the matrix material with an embedded 316L stainless steel wire spiral skeleton, and the inner and outer structures of the shell 3 were manufactured using micro-injection molding molds. The articular process 21 is elastically bent by a micro gripper, and the long axis of the articular process 21 is aligned with the short axis of the elliptical cavity 33 of the housing 3 and inserted. After release, the articular process 21 is embedded into the elliptical cavity 33 by the elastic force of the material to achieve self-alignment. The housing 3 is bonded to the base 5 using a special adhesive. The base 5 has threaded holes, which are used to install it onto the device under test.

[0039] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0040] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A biomimetic cantilever beam sensor for measuring vibration frequency, characterized in that, include: case; A counterweight is disposed within the housing; The main cantilever beam is disposed within the housing. The top end of the main cantilever beam is connected to the counterweight, and the end end is provided with an articular protrusion, which is movably connected within the housing. The secondary cantilever beam structure comprises multiple secondary cantilever beam structures evenly distributed circumferentially on the side surface of the main cantilever beam.

2. The biomimetic cantilever beam sensor according to claim 1, characterized in that, The articular process is clearance-fitted with the housing.

3. The biomimetic cantilever beam sensor according to claim 1, characterized in that, The secondary cantilever beam structure comprises multiple secondary cantilever beams with varying length gradients and connecting parts. One end of each secondary cantilever beam with varying length gradients is fixed to the connecting part; one end of each connecting part is fixed to the main cantilever beam.

4. The biomimetic cantilever beam sensor according to claim 3, characterized in that, The multiple secondary cantilever beams with varying length gradients are evenly spaced on the connecting part.

5. The biomimetic cantilever beam sensor according to claim 4, characterized in that, The secondary cantilever beams near the connection between the connecting part and the main cantilever beam are arranged in order of increasing length.

6. The biomimetic cantilever beam sensor according to claim 3, characterized in that, The connecting part has a fan-shaped structure.

7. The biomimetic cantilever beam sensor according to claim 1, characterized in that, The counterweight is made of tungsten alloy or platinum alloy and is mechanically fixed to the main cantilever beam by means of threads or riveting.

8. The biomimetic cantilever beam sensor according to claim 1, characterized in that, The inner wall of the shell is provided with a limiting part and a reinforcing rib.

9. A vibration frequency identification system, characterized in that, include: The biomimetic cantilever beam sensor as described in any one of claims 1-8; Strain gauges are installed at the fixed end of the secondary cantilever beam; The controller is communicatively connected to the strain gauge, and performs differential amplification, RMS amplitude calculation, resonance determination, and outputs the main frequency signal for multiple strain signals. Additional equipment, connected to the controller, is used to display, record, or utilize the main frequency signal and to power the system.

10. The identification system according to claim 9, characterized in that, The additional equipment is an energy recovery circuit that recovers the mechanical energy generated by the vibration of the secondary cantilever beam, the main cantilever beam, and the counterweight through piezoelectric or electromagnetic means, and supplies power to the controller and strain gauges.

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