Signal frequency selection enhancement detector and signal testing method

Abstract

The application discloses a signal frequency selection enhancement detector and a signal testing method, and belongs to the technical field of fault detection. The signal frequency selection enhancement detector comprises a base and a drum plate. The drum plate is located in a containing groove of the base. The drum plate has four spiral parts. The four spiral parts are arranged around the center of the drum plate, and gaps exist between adjacent spiral parts. The base has an adjusting part. The circumference of the base has at least four first adjusting holes. The circumference of the drum plate has second adjusting holes corresponding to the first adjusting holes. The second adjusting holes penetrate from one side of the spiral part to the other side. The first adjusting holes and the second adjusting holes are used for the adjusting part to pass through, so that the adjusting part has at least four moving positions in the radial direction of the drum plate. Two adjacent spiral parts are connected through the adjusting part. The free vibration length of the spiral part changes correspondingly when the position of the spiral part is limited. The equivalent stiffness of the signal frequency selection enhancement detector changes regularly, so that different resonance frequencies are obtained, and the signal is selectively enhanced at a specific frequency.

Description

Technical Field

[0001] This invention belongs to the technical field of fault detection, specifically relating to a signal frequency-selective enhancement detector and a signal testing method. Background Technology

[0002] In the past two years, the development of artificially engineered elastic wave metamaterials / metastructures to achieve acoustic vibration modulation performance has been extensive. Detection systems based on metamaterials / metastructures offer limitless possibilities for improving the detection limits of industrial acoustic vibration sensors, increasing the signal-to-noise ratio of key acoustic vibration signals, and enhancing the efficiency of mechanical condition monitoring and fault diagnosis. There are already several cases of using metastructures to overcome the detection limits of ordinary acoustic vibration sensors. For example, spatially coiled structures possess acoustic focusing characteristics, which can effectively amplify acoustic signals of specific frequencies. Furthermore, acoustic metastructure devices with gradient refractive indices can be used to detect weak acoustic signals and effectively amplify periodic pulse signals or specific harmonic frequencies from background noise.

[0003] Currently, most research focuses on the enhancement and detection of acoustic signals, primarily using devices such as gradient superstructures and phononic crystal defect structures. There are no readily available examples of superstructures for enhancing or amplifying vibration signals. Furthermore, once structure-based signal enhancement detectors are designed and fabricated, their frequency response characteristics are predetermined, lacking frequency selectivity and modulation capabilities. Summary of the Invention

[0004] The purpose of this invention is to provide a signal frequency-selective enhancement detector and a signal testing method, which realizes fault diagnosis or enhancement detection of weak signals, and by adjusting the equivalent parameters of the signal frequency-selective enhancement detector, the signal is selectively enhanced at a specific frequency.

[0005] The technical solution is as follows:

[0006] A frequency-selective enhancement detector includes a base and a drum plate, the drum plate being located in a receiving groove of the base, the drum plate having at least four helical members arranged around the center of the drum plate, and a gap between adjacent helical members;

[0007] The base has an adjusting member, and the base has at least four first adjusting holes in its circumferential direction. The drum plate has a second adjusting hole in its circumferential direction corresponding to the first adjusting holes. The second adjusting hole extends from one side of the spiral member to the other side. The first adjusting holes and the second adjusting holes are used for the adjusting member to pass through, so that the adjusting member has at least four moving positions in the radial direction of the drum plate. Two adjacent spiral members are connected by the adjusting member.

[0008] In one embodiment, the four spiral members are a first spiral member, a second spiral member, a third spiral member, and a fourth spiral member. In a first moving position, the adjusting member is at least partially located within the first spiral member. In a second moving position, the first spiral member and the second spiral member are connected in the radial direction of the drum plate. In a third moving position, the first, second, and third spiral members are connected in the radial direction of the drum plate. In a fourth moving position, the first, second, third, and fourth spiral members are connected in the radial direction of the drum plate.

[0009] In one embodiment, the adjusting member further has a fifth moving position, in which the adjusting member sequentially passes through the first spiral member, the second spiral member, the third spiral member, and the fourth spiral member, and abuts against the center of the drum plate.

[0010] In one embodiment, the starting ends of the four spiral members are equidistantly distributed in the circumferential direction of the drum.

[0011] In one embodiment, two adjacent spiral members are arranged in parallel; the inner diameter of the first adjusting hole is equal to the inner diameter of the second adjusting hole.

[0012] In one embodiment, the center of the drum plate has a boss, the top of which is higher than the upper surface of the auger.

[0013] In one embodiment, the inner wall of the first adjusting hole or the second adjusting hole has an internal thread, the outer wall of the adjusting member has an external thread, and the adjusting member is threadedly engaged with the first adjusting hole or the second adjusting hole.

[0014] The end of the adjusting member has a cap, the cross-section of which is polygonal, and the outer diameter of which is larger than the inner diameter of the first adjusting hole or the second adjusting hole.

[0015] This invention also proposes a signal testing method, comprising the following steps:

[0016] Step 1: Fix the signal frequency selective enhancement detector on the exciter for signal testing. Use the first accelerometer between the exciter and the signal frequency selective enhancement detector to obtain the frequency response value of the exciter.

[0017] Step 2: A second accelerometer is placed at the center of the signal frequency selective enhancement detector to obtain the frequency response value after enhancement by the signal frequency selective enhancement detector.

[0018] In one embodiment, a function generator and a linear power amplifier are connected to the exciter to drive the exciter to output a sweep frequency signal, and the frequency response values ​​of the adjustment member at the first moving position, the second moving position, the third moving position, the fourth moving position and the fifth moving position are tested respectively.

[0019] The frequency response value is recorded using a data acquisition system.

[0020] In one embodiment, the signal frequency-selective enhancement detector obtains different resonant frequencies at different moving positions of the adjusting member. The resonant frequency of the signal frequency-selective enhancement detector is expressed by the formula:

[0021]

[0022] Where, ω r n is the resonant frequency of the frequency-selective enhancement detector. b K represents the number of spiral components. eff Let m be the equivalent stiffness of the center of the signal frequency selective enhancement detector, m be the concentrated mass at the central boss of the signal frequency selective enhancement detector, F be the unit force applied to the center of the signal frequency selective enhancement detector, and D be the total vertical displacement of the center of the signal frequency selective enhancement detector.

[0023] The technical solution provided by this invention has the following advantages and effects:

[0024] 1. Four spiral components are arranged around the center of the drum plate. Due to the gaps between adjacent spiral components, the spiral components have a free-vibrating arc. When the vibration source is located at the bottom of the frequency-selective enhancement detector, the frequency response generated by the vibration source will be transmitted to the center of the drum plate through the spiral components. A first adjustment hole is provided in the circumference of the base, and a second adjustment hole corresponding to the first adjustment hole is provided in the circumference of the drum plate. The adjustment component passes through the first and second adjustment holes, thereby limiting the amplitude of two adjacent spiral components and the combined stiffness of multiple spiral components. The closer the adjustment component moves to the center of the drum plate, the greater the combined stiffness of its four spiral components becomes as the depth of the adjustment component screwed into the center of the drum plate increases. As the screw is restricted, its free vibration length gradually decreases from the outer side to the inner side of the drum plate. Because the screw is restricted at different positions, its free vibration length changes accordingly, causing a regular change in the equivalent stiffness of the frequency-selective signal enhancement detector to obtain different resonant frequencies. This enables fault diagnosis or enhanced detection of weak signals and adjusts the stiffness of the frequency-selective signal enhancement detector to select the frequency of the signal. As the adjusting element moves closer to the center of the drum plate, the vibration length of the screw decreases, and the vibration frequency of the drum plate increases accordingly, enhancing the signal detection capability of the frequency-selective signal enhancement detector at the corresponding frequency.

[0025] 2. When the adjusting member is in the first moving position, it is at least partially located within the first helical member, thus limiting the vibration length of the first helical member. When the adjusting member is in the second moving position, the first and second helical members are connected in the radial direction of the drum plate, thereby limiting the combined stiffness of the first and second helical members or the vibration length of their combination. When the adjusting member is in the third moving position, the first, second, and third helical members are connected in the radial direction of the drum plate, thereby limiting the combined stiffness of the first, second, and third helical members or the vibration length of their combination. When the adjusting member is in the fourth moving position, the first, second, third, and fourth helical members are connected in the radial direction of the drum plate, thereby limiting the combined stiffness of the first, second, third, and fourth helical members or the vibration length of their combination. The combined stiffness of the signal frequency-selective enhancement detector is further adjusted to perform signal frequency selection.

[0026] 3. In the fifth moving position, the adjusting member passes through the first spiral member, the second spiral member, the third spiral member and the fourth spiral member in sequence, and abuts against the center of the drum plate, thereby completely restricting the spiral members and further adjusting the combined stiffness of the spiral members.

[0027] 4. During use, the adjusting component can sequentially limit the vibration length of each spiral component through the corresponding first adjusting hole and second adjusting hole, and the starting ends of the four spiral components are equally distributed in the circumferential direction of the drum plate, so that the position of the adjusting component on each spiral component is consistent, ensuring that the position of the adjusting component limits the length of the spiral component to the same value at the same time.

[0028] 5. The two adjacent spiral components are arranged in parallel to avoid the two spiral components abutting each other when the adjustment component is not inserted into the first adjustment hole and the second adjustment hole, thereby avoiding affecting the resonant frequency of the frequency-selective enhancement detector for testing the signal; the inner diameter of the first adjustment hole is equal to the inner diameter of the second adjustment hole to avoid the phenomenon of shaking between the spiral component and the base, thereby improving the connection stability between the drum plate and the base, as well as the connection stability between the drum plate and the spiral component.

[0029] 6. The center of this drum plate has a boss, the top of which is higher than the upper surface of the spiral component. This boss facilitates the installation of an acceleration sensor.

[0030] 7. The outer wall of the adjusting component is provided with an external thread, and the inner wall of the first adjusting hole or the second adjusting hole is provided with an internal thread; so that the adjusting component is threadedly connected to the screw component, improving the flexibility of the adjusting component entering the first adjusting hole and the second adjusting hole, so as to facilitate the adjustment of the combined stiffness of the screw component.

[0031] 8. This signal testing method verified the frequency response of the frequency-selective enhancement detector 100, obtaining its true frequency-selective enhancement capability.Figure 8 The experimentally measured frequency response results are shown. Due to the difference from the ideal boundary of the finite element method, there is some noise interference in the frequency response. Figure 8 The results show that the actual enhancement performance and frequency selectivity of the device are highly consistent with the frequency response results obtained from the finite element model, meeting the design requirements and practical applications. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a signal frequency-selective enhancement detector in one embodiment of the present invention.

[0033] Figure 2 This is an exploded view of a signal frequency-selective enhancement detector in one embodiment of the present invention.

[0034] Figure 3 This is a top view of the signal frequency-selective enhancement detector in one embodiment of the present invention. Figure 1 .

[0035] Figure 4 This is a top view of the signal frequency-selective enhancement detector in one embodiment of the present invention. Figure 2 .

[0036] Figure 5 This is a numerical simulation diagram of a signal frequency-selective enhancement detector in one embodiment of the present invention.

[0037] Figure 6 This is an effective data effect diagram of the signal frequency selective enhancement detector after numerical simulation in one embodiment of the present invention.

[0038] Figure 7 This is a flowchart of a signal testing method for a frequency-selective enhancement detector according to an embodiment of the present invention.

[0039] Figure 8 This is a diagram showing the effective data effect of the signal frequency-selective enhancement detector after detection in one embodiment of the present invention.

[0040] Figure 9 This is a schematic diagram of the theoretical model of a signal frequency-selective enhancement detector in one embodiment of the present invention.

[0041] Figure 10 This is a schematic diagram of the signal frequency-selective enhancement detector after theoretical calculation in one embodiment of the present invention.

[0042] Explanation of reference numerals in the attached figures:

[0043] 100. Signal frequency selective enhancement detector; 10. Base; 101. First adjustment hole; 102. Receiving groove; 20. Adjustment component; 30. Drum plate; 301. Second adjustment hole; 40. Boss; 50. Gap; 60. First spiral component; 70. Second spiral component; 80. Third spiral component; 90. Fourth spiral component; 1. First moving position; 2. Second moving position; 3. Third moving position; 4. Fourth moving position. Detailed Implementation

[0044] To facilitate understanding of the present invention, specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0045] Unless otherwise specified or defined, the terms "first," "second," etc., used in this document are for distinguishing names only and do not represent a specific number or order.

[0046] Unless otherwise stated or defined, the term “and / or” as used herein includes any and all combinations of one or more of the associated listed items.

[0047] It should be noted that in this article, "fixed to" or "connected to" can mean directly fixed to or connected to a component, or indirectly fixed to or connected to a component.

[0048] like Figures 1 to 4As shown, a signal frequency-selective enhancement detector 100 includes a base 10 and a drum plate 30. The drum plate 30 is located in a receiving groove 102 of the base 10. The drum plate 30 has a first spiral member 60, a second spiral member 70, a third spiral member 80, and a fourth spiral member 90. The four spiral members are arranged around the center of the drum plate 30, and there is a gap 50 between adjacent spiral members. The base 10 has an adjusting member 20. The base 10 has at least four first adjusting holes 101 in its circumferential direction. The drum plate 30 has second adjusting holes 301 in its circumferential direction corresponding to the first adjusting holes 101. The second adjusting holes 301 pass through one side of the spiral member to the other side. The first adjusting holes 101 and the second adjusting holes 301 are used for the adjusting member 20 to pass through, so that the adjusting member 20 has at least four moving positions in the radial direction of the drum plate 30. Adjacent spiral members are connected by the adjusting member 20. Four spiral members are arranged around the center of the drum plate 30. Due to the gap 50 between adjacent spiral members, the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 have free vibration arcs. When the vibration source is located at the bottom of the frequency-selective enhancement detector 100, the frequency response generated by the vibration source will be transmitted to the center of the drum plate 30 through the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90. A first adjustment hole 101 is provided circumferentially on the base 10, and a second adjustment hole 301 corresponding to the first adjustment hole 101 is provided circumferentially on the drum plate 30. The adjustment member 20 passes through the first adjustment hole 101 and the second adjustment hole 301, thereby limiting the amplitude of two adjacent spiral members and the combined stiffness of multiple spiral members. The closer the adjustment member 20 moves to the center of the drum plate 30, the greater the combined stiffness of its four spiral members. As the screw-in depth of the drum plate 30 increases, the free vibration length of the corresponding helical component is gradually restricted from the outside to the inside of the drum plate 30, and its vibration length decreases sequentially. Due to the different positions where the helical component is restricted, its free vibration length changes accordingly, resulting in a regular change in the equivalent stiffness of the signal frequency-selective enhancement detector 100 to obtain different resonant frequencies. This enables fault diagnosis or enhanced detection of weak signals, and adjusts the combined stiffness of the first helical component 60, the second helical component 70, the third helical component 80, and the fourth helical component 90 to select the frequency of the signal. As the adjusting component 20 moves closer to the center of the drum plate 30, the vibration length of the first helical component 60, the second helical component 70, the third helical component 80, and the fourth helical component 90 decreases sequentially, and the vibration frequency of the drum plate 30 increases accordingly. The signal frequency-selective enhancement detector 100's signal detection capability at the corresponding frequency is enhanced.

[0049] In this embodiment, the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 of the signal frequency selective enhancement detector 100 are arranged around the center of the drum plate, making the structure of the signal frequency selective enhancement detector 100 more compact and meeting the design requirements of miniaturization of the signal frequency selective enhancement detector 100.

[0050] like Figure 3 and Figure 4 As shown, in the first moving position 1, the adjusting member 20 is at least partially located within the first spiral member 60; in the second moving position 2, the first spiral member 60 and the second spiral member 70 are connected in the radial direction of the drum plate 30; in the third moving position 3, the first spiral member 60, the second spiral member 70, and the third spiral member 80 are connected in the radial direction of the drum plate 30; in the fourth moving position 4, the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 are connected in the radial direction of the drum plate 30. When the adjusting member 20 is in the first moving position 1, the adjusting member 20 is at least partially located within the first helical member 60, thereby limiting the vibration length of the first helical member 60; when the adjusting member 20 is in the second moving position 2, the first helical member 60 and the second helical member 70 are connected in the radial direction of the drum plate 30, thereby limiting the combined stiffness of the first helical member 60 and the second helical member 70 or the vibration length of their combination; when the adjusting member 20 is in the third moving position 3, the first helical member 60, the second helical member 70, and the third helical member 80 are connected in the radial direction of the drum plate 30, from The combined stiffness of the first helical member 60, the second helical member 70, and the third helical member 80, or the vibration length of their combination, is limited. When the adjusting member 20 is in the fourth moving position 4, the first helical member 60, the second helical member 70, the third helical member 80, and the fourth helical member 90 are connected in the radial direction of the drum plate 30, thereby limiting the combined stiffness of the first helical member 60, the second helical member 70, the third helical member 80, and the fourth helical member 90, or the vibration length of their combination. The combined stiffness of the signal frequency selective enhancement detector 100 is further adjusted to perform signal frequency selection.

[0051] In this embodiment, as Figure 4As shown, the first spiral component 60, the second spiral component 70, the third spiral component 80, and the fourth spiral component 90 are all based on the Archimedean spiral and are arranged in a periodic rotational pattern. The Archimedean spiral is the trajectory generated by a point moving away from a fixed point at a constant speed while rotating around that fixed point at a fixed angular velocity. The four spiral components have equal length, height, and width. The gap 50 between adjacent spiral components is p = 15.5 mm, the diameter of the spiral component is r = 25 mm, the length of the spiral component is l = 1.2π, the width of the spiral component is w = 5 mm, and the height of the spiral component is h1 = 5 mm. To enable the signal frequency selective enhancement detector 100 to obtain a selective enhancement frequency band to adapt to a wider range of scenarios, the spiral components of the signal frequency selective enhancement detector 100 are designed with adjustable stiffness. Multiple adjusting parts 20 can be screwed into different positions on the side of the signal frequency selective enhancement detector 100 to adjust the stiffness of the drum plate 30. The principle behind this detector is to limit the free vibration lengths of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 through adjusting members 20. Due to differences in the screw-in length or position of the adjusting members 20, the signal frequency selective enhancement detector 100 will obtain different equivalent combined stiffnesses, achieving rich vibration frequency selectivity characteristics. The signal frequency selective enhancement detector 100 has a total of 12 adjusting members 20. As each adjusting member 20 moves towards the center of the drum plate 30, the free vibration lengths of the corresponding first spiral member 60, second spiral member 70, third spiral member 80, and fourth spiral member 90 will be gradually limited from the outermost edge towards the center of the drum plate 30. Through the mixed adjustment of the 12 adjusting members 20, a richer frequency bandwidth or the effect of multiple frequency coupling can be obtained. In this embodiment, the drum plate 30 only needs to consider three completely different screw-in positions: A, B, and C. All other circumferential positions of the drum plate 30 have rotational periodicity relative to A, B, and C. That is, all positions A, B, or C simultaneously restrict the lengths of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 to the same length. Therefore, taking the B-2 mode as an example, it means that the free vibration length of all spiral members is restricted one by one outside the second moving position 2.

[0052] like Figure 4 As shown, the adjusting member 20 also has a fifth movable position. In this fifth movable position, the adjusting member 20 sequentially passes through the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90, and abuts against the center of the drum plate 30. This completely restricts the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90, and further adjusts the combined stiffness of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90.

[0053] like Figure 3 and Figure 4As shown, the starting ends of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 are equidistantly distributed in the circumferential direction of the drum plate 30. In use, the adjusting member 20 can sequentially limit the vibration length of each spiral member through the corresponding first adjusting hole 101 and second adjusting hole 301. Furthermore, the equidistant distribution of the starting ends of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 in the circumferential direction of the drum plate 30 ensures that the position of the adjusting member 20 on each spiral member remains consistent, guaranteeing that at any given moment, the position of the adjusting member 20 limits the lengths of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90 to the same value.

[0054] like Figure 3 and Figure 4 As shown, two adjacent spiral components are arranged in parallel; the inner diameter of the first adjustment hole 101 is equal to the inner diameter of the second adjustment hole 301. The parallel arrangement of the two adjacent spiral components prevents them from abutting when the adjustment component 20 is not inserted into the first adjustment hole 101 or the second adjustment hole 301, thus avoiding affecting the resonant frequency of the frequency-selective enhancement detector 100 used for testing the signal. Equal inner diameters of the first adjustment hole 101 and the second adjustment hole 301 prevent wobbling between the first spiral component 60, the second spiral component 70, the third spiral component 80, and the fourth spiral component 90 and the base 10, improving the connection stability between the drum plate 30 and the base 10, as well as the connection stability between the drum plate 30 and the first spiral component 60, the second spiral component 70, the third spiral component 80, and the fourth spiral component 90.

[0055] like Figure 1 and Figure 2 As shown, the center of the drum plate 30 has a boss 40, the top of which is higher than the upper surfaces of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90. This boss 40 facilitates the installation of the second acceleration sensor.

[0056] Furthermore, the inner wall of the first adjusting hole 101 or the second adjusting hole 301 has internal threads, and the outer wall of the adjusting member 20 has external threads. The adjusting member 20 is threadedly engaged with the first adjusting hole 101 or the second adjusting hole 301. This allows the adjusting member 20 to be threadedly connected to the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90, improving the flexibility of the adjusting member 20 entering the first adjusting hole 101 and the second adjusting hole 301, thus facilitating the adjustment of the combined rigidity of the first spiral member 60, the second spiral member 70, the third spiral member 80, and the fourth spiral member 90. The end of the adjusting member 20 has a cap, the outer diameter of which is larger than the inner diameter of the first adjusting hole 101 or the second adjusting hole 301. This cap is polygonal, making it easy to hold the adjusting member 20. By rotating the adjusting member 20 through the cap, the adjusting member 20 can be moved to the first moving position 1, the second moving position 2, the third moving position 3, and the fourth moving position 4.

[0057] like Figure 7 and Figure 8 As shown, the present invention also proposes a signal testing method, comprising the following steps:

[0058] Step 1: Fix the signal frequency selective enhancement detector 100 on the exciter for signal testing. Use a first accelerometer between the exciter and the signal frequency selective enhancement detector 100 to obtain the frequency response value of the exciter.

[0059] Step 2: A second accelerometer is installed on the protrusion 40 of the signal frequency selective enhancement detector 100 to obtain the frequency response value after being enhanced by the signal frequency selective enhancement detector 100.

[0060] Figure 7 This is an experimental flowchart of the signal testing method for the frequency-selective enhancement detector 100. The bottom of the frequency-selective enhancement detector 100 faces the exciter, and the second accelerometer is mounted on the protrusion 40 of the drum plate 30, opposite to the exciter. This signal testing method verifies the frequency response of the frequency-selective enhancement detector 100, obtaining its true frequency-selective enhancement capability. Figure 8 The experimentally measured frequency response results are shown. Due to the difference from the ideal boundary of the finite element method, there is some noise interference in the frequency response. Figure 8 The results show that the actual enhancement performance and frequency selectivity of the device are highly consistent with the frequency response results obtained from the finite element model, meeting the design requirements and practical applications.

[0061] like Figure 7As shown, a function generator and a linear power amplifier are connected to the exciter to drive the exciter to output a sweep frequency signal. The frequency response values ​​of the adjusting component 20 at the first moving position 1, the second moving position 2, the third moving position 3, the fourth moving position 4, and the fifth moving position are tested respectively. The frequency response values ​​are recorded using a data acquisition system, and then the data is analyzed to obtain the results. Figure 8 The trend chart of normalized amplitude and frequency.

[0062] like Figure 5 and Figure 6 As shown, numerical simulations were performed using the commercial finite element software COMSOL 5.5 to calculate the frequency enhancement and frequency selectivity capabilities of the frequency-selective signal enhancement detector 100. Figure 5 As shown, a sweeping acceleration excitation is applied to the bottom of the signal frequency selective enhancement detector 100. An additional mass m = 5g is added at the center of the signal frequency selective enhancement detector 100 to simulate the mass of an accelerometer, and the vibration output signal is picked up and recorded at the center of the signal frequency selective enhancement detector 100 to obtain the frequency response.

[0063] like Figure 5 As shown, the first spiral component 60, the second spiral component 70, the third spiral component 80, and the fourth spiral component 90 are composed of red and blue regions. The vibration length of the spiral component in the red region is not limited by the adjusting component 20, while the vibration length of the spiral component in the blue region is limited by the adjusting component 20. Figure 6 The frequency response curves obtained from numerical simulations are shown, clearly demonstrating that the adjustment element 20 enables the frequency-selective enhancement detector 100 to exhibit excellent frequency-selective enhancement characteristics. In mode B-2, the enhanced center frequency is approximately 210 Hz, and the enhancement bandwidth is approximately 200 Hz. Furthermore, as the adjustment element 20 moves closer to the center of the drum plate 30, from position B-2 to position B-3, the center frequency of the frequency-selective enhancement detector 100 gradually increases at a rate of approximately 150 Hz. Upon reaching mode B-4, the enhanced center frequency approaches 1000 Hz, and the enhancement bandwidth correspondingly increases to approximately 400 Hz. Figure 6 The mode shapes corresponding to the device in modes B-2, A-3, C-3, and B-4 were extracted. In this embodiment, mode B-2 represents the measurement point when the adjusting member 20 is screwed into position B-2, mode A-3 represents the measurement point when the adjusting member 20 is screwed into position A-3, mode C-3 represents the measurement point when the adjusting member 20 is screwed into position C-3, and mode B-4 represents the measurement point when the adjusting member 20 is screwed into position B-4.

[0064] Furthermore, at different moving positions, the signal frequency selective enhancement detector 100 obtains different resonant frequencies, and the resonant frequency of the signal frequency selective enhancement detector 100 is expressed by the formula:

[0065]

[0066] Where, ω r n is the resonant frequency of the frequency-selective enhancement detector 100. b K represents the number of spiral components. eff Let m be the equivalent stiffness of the center of the signal frequency selective enhancement detector 100, m be the concentrated mass at the central boss of the signal frequency selective enhancement detector 100, F be the unit force applied to the center of the signal frequency selective enhancement detector 100, and D be the total vertical displacement of the center of the signal frequency selective enhancement detector 100.

[0067] Furthermore, the resonant frequency of the frequency-selective enhancement detector 100 can be derived using the following formula, where D is the total vertical displacement of the center of the frequency-selective enhancement detector 100, expressed by the formula:

[0068]

[0069] like Figure 9 As shown, R(θ) is the vector from the origin o to the restricted position at angle θ, R′(θ) is the derivative of R(θ), and d is the differential sign. M is the total helix angle of the screw component from point a to point b, which is the restricted position. b (θ) is the bending moment of the helical component at angle θ, M t (θ) represents the torque of the helical component at angle θ.

[0070] also,

[0071] Among them, I b Let v be the moment of inertia of the cross section, μ be the shear modulus, A be the effective shear area, and v be the effective shear area. p For Poisson's ratio, E p Here, E represents Young's modulus, and w represents the width of the helical component. In this embodiment, the frequency-selective enhancement detector 100 can be made of polylactic acid (PLA), which has a Young's modulus of E. p = 3.8 GPa, Poisson's ratio is u p =0.34, density is ρ p =1250kg / m 3 .

[0072] In addition, the torsional moment of inertia I of the helical component t Expressed as a formula:

[0073]

[0074] Among them, I t Let h1 be the torsional inertia of the helical component and h1 be the height of the helical component.

[0075] By deriving the above equations, the resonant frequency ω of the frequency-selective enhancement detector 100 can be estimated. r ;pass Figure 10 It can be seen that the frequency values ​​of the spiral component are located at different positions of the adjusting component 20.

[0076] The above embodiments are not an exhaustive list based on the present invention, and there may be many other embodiments not listed. Any substitutions and improvements made without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A signal frequency-selective enhancement detector, characterized in that, It includes a base and a drum plate, the drum plate being located in a receiving groove of the base, the drum plate having at least four helical members arranged around the center of the drum plate, and a gap between adjacent helical members; The base has an adjusting member, and the base has at least four first adjusting holes in its circumferential direction. The drum plate has a second adjusting hole in its circumferential direction corresponding to the first adjusting holes. The second adjusting hole extends from one side of the spiral member to the other side. The first adjusting holes and the second adjusting holes are used for the adjusting member to pass through, so that the adjusting member has at least four moving positions in the radial direction of the drum plate. Two adjacent spiral members are connected by the adjusting member. The four spiral components are a first spiral component, a second spiral component, a third spiral component, and a fourth spiral component. In the first moving position, the adjusting component is at least partially located within the first spiral component. In the second moving position, the first spiral component and the second spiral component are connected in the radial direction of the drum plate. In the third moving position, the first spiral component, the second spiral component, and the third spiral component are connected in the radial direction of the drum plate. In the fourth moving position, the first spiral component, the second spiral component, the third spiral component, and the fourth spiral component are connected in the radial direction of the drum plate.

2. The signal frequency-selective enhancement detector as described in claim 1, characterized in that... The adjusting member also has a fifth moving position, in which the adjusting member passes through the first spiral member, the second spiral member, the third spiral member and the fourth spiral member in sequence, and abuts against the center of the drum plate.

3. The signal frequency-selective enhancement detector as described in claim 1, characterized in that, The starting ends of the four spiral components are equidistantly distributed in the circumferential direction of the drum.

4. The signal frequency-selective enhancement detector as described in claim 1, characterized in that... The two adjacent spiral components are arranged in parallel; the inner diameter of the first adjusting hole is equal to the inner diameter of the second adjusting hole.

5. The signal frequency-selective enhancement detector as described in claim 1, characterized in that... The drum plate has a boss at its center, and the top of the boss is higher than the upper surface of the spiral component.

6. The signal frequency-selective enhancement detector as described in claim 1, characterized in that... The inner wall of the first adjustment hole or the second adjustment hole has an internal thread, and the outer wall of the adjustment member has an external thread. The adjustment member is threadedly engaged with the first adjustment hole or the second adjustment hole. The end of the adjusting member has a cap, the cross-section of which is polygonal, and the outer diameter of which is larger than the inner diameter of the first adjusting hole or the second adjusting hole.

7. A signal testing method based on the frequency-selective enhancement detector of claim 1, characterized in that... This includes the following steps: The signal frequency selective enhancement detector is fixed on the exciter for signal testing. The first accelerometer is set between the exciter and the signal frequency selective enhancement detector to obtain the frequency response value of the exciter. A second accelerometer is positioned at the center of the signal frequency selective enhancement detector to obtain the frequency response value after enhancement by the detector.

8. The signal testing method as described in claim 7, characterized in that... A function generator and a linear power amplifier are connected to the exciter to drive the exciter to output a sweep frequency signal, and the frequency response values ​​of the adjustment component at the first, second, third, fourth and fifth moving positions are tested respectively. The frequency response value is recorded using a data acquisition system.

9. The signal testing method as described in claim 7, characterized in that... At different moving positions of the adjusting element, the signal frequency-selective enhancement detector obtains different resonant frequencies. The resonant frequency of the signal frequency-selective enhancement detector is expressed by the formula: ； in, To enhance the resonant frequency of the frequency-selective detector, The number of spiral components, To enhance the equivalent stiffness of the detector center through signal frequency selection, To enhance the concentrated mass at the central boss of the frequency-selective detector; To apply a unit force to the center of the frequency-selective enhancement detector, The total vertical displacement of the detector center is to enhance the signal frequency selection.

Images