Biomimetic cantilever beam sensor and identification system for vibration frequency measurement

Abstract

The application relates to the technical field of vibration frequency measurement, in particular to a bionic cantilever beam sensor for vibration frequency measurement and a recognition system, which comprises a shell, a counterweight arranged in the shell, a main cantilever beam, the top end of which is connected with the counterweight, and the tail end is provided with a joint protrusion which is movably connected in the shell, and a plurality of secondary cantilever beam structures which are evenly distributed on the side surface of the main cantilever beam. The application is based on the bionics design of Johnstone organ of Aedes aegypti, and through the synergistic effect of the array formed by the main cantilever beam and the plurality of secondary cantilever beam structures, high sensitivity and wide frequency domain detection of the vibration frequency are realized, and the application is suitable for precise monitoring in a complex vibration environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vibration frequency measurement, and particularly relates to a bionic cantilever beam sensor for vibration frequency measurement and a recognition system. BACKGROUND

[0002] In recent years, vibration frequency detection has important significance in industrial monitoring, structural health diagnosis, aerospace, etc. The traditional vibration sensor has weak response in the low frequency band, poor signal-to-noise ratio, and is difficult to meet the demand of low frequency vibration monitoring. A single beam will produce deflection under transverse and longitudinal excitation, resulting in mutual interference of multi-directional vibration signals. In order to eliminate coupling, the existing scheme often adopts multiple groups of independent cantilever beams arranged orthogonally, but this makes the overall size of the sensor increase by several times, which is contrary to the trend of miniaturization of MEMS systems.

[0003] Micro-cantilever beam structure has been widely used in micro-electro-mechanical system sensors due to its high sensitivity and miniaturization. However, most of the current cantilever beam sensors still focus on static or quasi-static deformation detection, and there are few studies on cantilever beam sensors for dynamic vibration frequency identification. Although some improved schemes can improve sensitivity, they still cannot achieve efficient identification of multi-frequency vibration, and rely on complex sensor arrays, resulting in low system integration and increased cost. SUMMARY

[0004] Therefore, the present application aims to provide a bionic cantilever beam sensor for vibration frequency measurement and a recognition system to solve the problems in the prior art.

[0005] To achieve the above-mentioned purposes, the technical scheme of the present application is as follows:

[0006] In a first aspect, a bionic cantilever beam sensor for vibration frequency measurement comprises:

[0007] a housing;

[0008] a counterweight, arranged in the housing;

[0009] a main cantilever beam, arranged in the housing, the top end of the main cantilever beam being connected to the counterweight, and the end being provided with a joint protrusion, the joint protrusion being movably connected in the housing;

[0010] a plurality of secondary cantilever beam structures, arranged circumferentially on the side surface of the main cantilever beam.

[0011] Further, the joint protrusion is gap-fitted with the housing.

[0012] Further, the secondary cantilever beam structure comprises a plurality of secondary cantilever beams with gradient changes in length and a connecting part, one end of the secondary cantilever beam with gradient changes in length being fixed on the connecting part; one end of the connecting part being fixed on the main cantilever beam.

[0013] Further, the plurality of secondary cantilever beams with gradient changes in length are arranged at equal intervals on the connecting part.

[0014] Further, the secondary cantilever beams close to the connecting part of the main cantilever beam are arranged from short to long.

[0015] Further, the connecting part is in a fan shape.

[0016] Further, the counterweight is made of tungsten alloy or platinum alloy and is mechanically fixed on the main cantilever beam by screwing or riveting.

[0017] Further, the inner wall of the shell is provided with a limiting part and a reinforcing rib.

[0018] In a second aspect, a vibration frequency identification system comprises:

[0019] The bionic cantilever beam sensor described above;

[0020] Strain gauges arranged at fixed ends of the secondary cantilever beams;

[0021] A controller in communication connection with the strain gauges, performing differential amplification, RMS amplitude calculation, resonance determination and output of a main frequency signal on a plurality of strain signals;

[0022] An additional device connected to the controller, used for display, recording or utilization of the main frequency signal and power supply for the system.

[0023] Further, the additional device is an energy recovery circuit, which recovers mechanical energy generated by vibration of the secondary cantilever beam, the main cantilever beam and the counterweight by piezoelectric or electromagnetic method and supplies power to the controller and the strain gauges.

[0024] Compared with the prior art, the present application can achieve the following beneficial effects:

[0025] The present application discloses a bionic cantilever beam sensor and identification system for vibration frequency measurement, which realizes high sensitivity and wide frequency domain detection of vibration frequency through the synergistic effect of the main cantilever beam and the secondary cantilever beam structure array, and is suitable for precise monitoring in a complex vibration environment. The circumferentially distributed secondary cantilever beam structure forms a symmetrical "multi-directional filter", which presents spatial weighted response to vibration in different directions; in cooperation with the articular process and the counterweight, axial crosstalk can be effectively suppressed, the effective working frequency band is widened, and the quality factor of the resonance peak is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, illustrate preferred embodiments of the application, and assist in explaining the application. In the drawings:

[0027] Figure 1 A schematic diagram of a bionic cantilever beam sensor structure for vibration frequency measurement according to an embodiment of the present application;

[0028] Figure 2 A schematic diagram of a primary cantilever beam of a bionic cantilever beam sensor for vibration frequency measurement according to an embodiment of the present application;

[0029] Figure 3 A schematic diagram of a pair of secondary cantilever beams of a bionic cantilever beam sensor for vibration frequency measurement according to an embodiment of the present application;

[0030] Figure 4 A schematic diagram of internal structure of Johnstone organ of Aedes aegypti according to an embodiment of the present application;

[0031] Figure 5 A schematic diagram of a housing of a bionic cantilever beam sensor for vibration frequency measurement according to an embodiment of the present application.

[0032] In the drawings: 1, counterweight, 2, primary cantilever beam, 21, processus articularis, 3, housing, 31, limiting portion, 32, reinforcing rib, 33, oval cavity, 4, secondary cantilever beam structure, 41, secondary cantilever beam, 42, connecting portion, 5, base. DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and do not constitute limitation on the present application. In different embodiments, similar elements are associated with similar element labels. In the following embodiments, many details are described in order to make the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different cases, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification in order to avoid the core part of the present application being overwhelmed by too much description, and it is not necessary to describe these related operations in detail for those skilled in the art according to the description in the specification and general technical knowledge in the art.

[0034] It should be noted that the embodiments and features of the embodiments in the present application can be combined with each other to form various embodiments without conflict. Meanwhile, each step or action in the method description can also be sequentially changed or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the description and the drawings are only for the purpose of clearly describing a certain embodiment, and do not mean that the sequence is necessary. Unless otherwise stated, a certain sequence must be followed.

[0035] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In the related art, satellite ground vibration detection is a key link to ensure the reliability of the satellite, which needs to simulate the complex vibration environment of the rocket engine and the return stage before launch. Traditional sensors, such as piezoelectric accelerometers, MEMS, etc. have defects such as poor low-frequency response, weak anti-interference, insufficient frequency band coverage, etc. In order to solve at least one of the technical problems existing in the above related technology, the present application provides a bionic cantilever beam sensor for vibration frequency measurement and identification system, Figure 1 A structural schematic diagram of a bionic cantilever beam sensor for vibration frequency measurement provided by the embodiment of the present application; comprising:

[0038] Housing 3; In this embodiment, fluororubber is selected as the matrix material, and 316L stainless steel wire is embedded as the spiral skeleton; Housing 3 is installed on the device under test via base 5;

[0039] Counterweight 1, wherein the counterweight 1 is disposed within the housing 3;

[0040] 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 2 As shown, the articular process 21 is movably connected to the housing 1 and is clearance-fitted with the housing 3;

[0041] Secondary cantilever beam structures 4, a plurality of which are circumferentially distributed on the side surface of the main cantilever beam 2.

[0042] 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 gradient 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.

[0043] 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.

[0044] 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 5As shown, the elliptical cavity 33 at the bottom of the shell 3 drives the vibration of the processus articularis 21 of the main cantilever beam 2, and the limiting part 31 at the top of the shell 3 prevents the main cantilever beam 2 from deflecting too much, thereby inhibiting the vibration amplitude of the main cantilever beam 2. Since 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 at the middle part of the shell 3, which prevents the fluorine rubber at the bottom of the shell 3 from being compressed when the main cantilever beam 2 deflects, thereby causing local stress concentration of the shell 3, and dispersing stress and delaying local deformation of the shell 3.

[0045] 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 processus articularis 21 of the main cantilever beam 2 and the counterweight 1 ensure the vibration direction of the main cantilever beam 2 and inhibit axial interference.

[0046] The vibration is transmitted from the main cantilever beam 2 to the secondary cantilever beam 41, and the vibration at the root of the main cantilever beam 2 drives 8 groups of secondary cantilever beam structures 4 to vibrate synchronously. The secondary cantilever beams 41 in each group of secondary cantilever beam structures 4 have different lengths, and the inherent frequency distribution of the secondary cantilever beams 41 with different lengths covers the target frequency band. When the input vibration frequency approaches the inherent frequency of a certain secondary cantilever beam 41, the amplitude of the secondary cantilever beam 41 is significantly increased compared with other secondary cantilever beams 41. Among them, the short secondary cantilever beam 41 realizes high-frequency resonance, the medium-long secondary cantilever beam 41 realizes medium-frequency resonance, and the long secondary cantilever beam 41 realizes low-frequency resonance.

[0047] The resonance frequency of the secondary cantilever beam 41 is related to its geometric size and material properties. For a uniform secondary cantilever beam 41, the nth order inherent frequency can be expressed as:

[0048]

[0049] wherein is a constant related to the vibration mode, E is the Young's modulus of the material of the secondary cantilever beam 41, I is the cross-sectional moment of inertia of the secondary cantilever beam 41, is the density of the material of the secondary cantilever beam 41, is the cross-sectional area of the secondary cantilever beam 41, is the length of the secondary cantilever beam 41.

[0050] In a second aspect, an embodiment of the present application provides a vibration frequency identification system, comprising:

[0051] The above-mentioned bionic cantilever beam sensor.

[0052] A strain gauge is arranged 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; wherein the strain signal amplitude of the resonant secondary cantilever beam 41 is significantly different from that of the non-resonant secondary cantilever beam 41.

[0053] The controller is in communication with the strain gauges, and performs differential amplification, RMS amplitude calculation, resonance determination and output of the main frequency signal on the multi-channel strain signals; by controlling the synchronous sampling of the multi-channel ADC, the time alignment of the data of each sensing channel is ensured. When there is no vibration input, the static offset voltage of each channel is recorded to eliminate the zero drift. The original signal is digitally band-pass filtered to suppress low-frequency noise and high-frequency interference. When there is vibration input, the root mean square (RMS) voltage of the vibration signal of each sensing channel is calculated, reflecting the vibration energy of each secondary cantilever beam 41. The signals of the secondary cantilever beams 41 in the same secondary cantilever beam structure group are processed by intra-group difference to further highlight the response of the resonant secondary cantilever beam 41.

[0054] The root mean square formula is:

[0055]

[0056] wherein, represents the original voltage value of the vibration signal output by one sensing channel collected at the i-th sampling point, and N represents the total number of sampling points, represents the root mean square voltage of the vibration signal output by one sensing channel.

[0057] As shown in Figure 2 , the amplitudes of the secondary cantilever beams 41 of the same number in the 8 groups of secondary cantilever beam structures 4 are compared (such as all #7 beams), and if a certain number of beams shows the maximum amplitude in the four groups (such as #7 beam amplitude > #6, #8 beam), it is determined that the #7 beam is the resonance main frequency carrier. Before shipment, the natural frequency of each secondary cantilever beam 41 is calibrated by a frequency sweep experiment, and the real-time lookup table logic is used: if the #7 beam has the maximum amplitude in all sensing channels, the pre-stored mapping table is directly called to output the corresponding frequency value, and the digital interface is used to transmit the frequency value to the upper computer.

[0058] The controller executes the following algorithm:

[0059] Synchronously sampling each strain gauge sensing channel to obtain a vibration signal;

[0060] Digitally band-pass filtering each channel signal to remove common-mode noise;

[0061] Calculating the RMS value of the filtered signal, and determining the resonant beam of the secondary cantilever beam 41 as the one with the maximum RMS value;

[0062] Outputting the natural frequency corresponding to the resonant beam according to the pre-stored mapping table as the current vibration main frequency.

[0063] An additional device is connected to the controller for displaying, recording or utilizing the main frequency signal and providing power for the system. The additional device is an energy recovery circuit which recovers mechanical energy generated by the vibration of the secondary cantilever beam 41, the main cantilever beam 2 and the counterweight 1 through piezoelectric or electromagnetic methods and supplies power to the controller and the strain gauges.

[0064] In a third aspect, the present application provides a preparation method of the bionic cantilever beam sensor for vibration frequency measurement as described above, comprising:

[0065] The main cantilever beam 2 and the secondary cantilever beam 41 are prepared by using a material containing one or more of polyurethane acrylate or metal;

[0066] The resonance frequencies of the secondary cantilever beams 41 of each order of the secondary cantilever beam structure 4 are obtained through finite element simulation and calculation;

[0067] The main cantilever beam 2 and the secondary cantilever beam structure 4 are printed by 3D integrated printing, and the strain gauge mounting interface of the secondary cantilever beam 41 is reserved;

[0068] The counterweight is made of high-density metal, such as tungsten alloy or platinum alloy, and is mechanically fixed to the top end of the main cantilever beam 2;

[0069] Fluorine rubber is selected as the base material to embed a 316L stainless steel wire spiral skeleton, and a micro-injection molding mold is used to manufacture the inner and outer structures of the shell 3;

[0070] The elastic bending of the articular process 21 is generated by the micro-gripper, the long axis direction of the articular process 21 is aligned with the short axis direction of the elliptical cavity 33 of the shell 3, and the articular process 21 is inserted, and after release, the articular process 21 is embedded in the elliptical cavity 33 to realize self-alignment by the material resilience;

[0071] The shell 3 is adhered to the base 5 by using a special adhesive;

[0072] The base 5 contains a threaded hole, which is installed on the measured device through the threaded hole.

[0073] It should be understood that the various forms of the flow shown above can be reordered, added or deleted steps. For example, the steps described in the present disclosure can be executed in parallel, sequentially or in different order, as long as the desired results of the technical solutions of the present disclosure can be achieved, which is not limited herein.

[0074] The above specific embodiments do not constitute a limitation on the scope of protection of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A bionic cantilever beam sensor for vibration frequency measurement, characterized in that, The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor.

2. The biomimetic cantilever sensor according to claim 1, wherein, The application relates to a bionic cantilever beam sensor.

3. The biomimetic cantilever sensor of claim 1, wherein, The application relates to a bionic cantilever beam sensor.

4. The biomimetic cantilever sensor according to claim 3, wherein, The application relates to a bionic cantilever beam sensor.

5. The biomimetic cantilever sensor according to claim 4, wherein, The application relates to a bionic cantilever beam sensor.

6. The biomimetic cantilever sensor of claim 3, wherein, The application relates to a bionic cantilever beam sensor.

7. The biomimetic cantilever sensor of claim 1, wherein, The application relates to a bionic cantilever beam sensor.

8. The biomimetic cantilever sensor of claim 1, wherein, The application relates to a bionic cantilever beam sensor.

9. A vibration frequency identification system characterized by, The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor.

10. The identification system of claim 9, wherein, The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam sensor. The application relates to a bionic cantilever beam

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