Variable cross-section toroidal active vibration isolation element, method and vibration isolation device

Abstract

The application discloses a variable cross-section circular ring active vibration isolation element, a method and a vibration isolation device, wherein the variable cross-section circular ring active vibration isolation element comprises a variable cross-section circular ring structure, a piezoelectric sheet, an acceleration sensor and an active vibration reduction control device; the upper and lower sides of the variable cross-section circular ring structure are respectively provided with symmetrical connecting end faces; the cross section of the variable cross-section circular ring structure is in an arch shape, and two groups of grooves are arranged at the middle positions of the left and right sides of the variable cross-section circular ring structure; the two groups of grooves are respectively arranged on the inner and outer sides of the variable cross-section circular ring structure, and the piezoelectric sheet is arranged in the grooves; the acceleration sensor is arranged on the lower end face of the variable cross-section circular ring structure and is used for detecting a vibration source signal in real time; after analysis and processing by the active vibration reduction control device, a control signal is output to the piezoelectric sheet, the piezoelectric sheet generates a reverse piezoelectric effect to drive the variable cross-section circular ring structure to deform, and then the connecting end faces on the upper and lower sides are driven to generate relative displacement, so that the influence of the vibration source on the load is reduced.

Description

Technical Field

[0001] This invention relates to a vibration reduction device, specifically to a variable cross-section circular ring active vibration isolation element, method, and vibration isolation device. Background Technology

[0002] In the field of low-frequency vibration isolation, passive, active, and semi-active vibration isolation technologies are currently widely used. Passive control is characterized by not requiring external energy, simple structure, high reliability, and applicability to various applications. Rubber materials are commonly used passive vibration isolation materials; their composition and structure can be adjusted over a wide range to achieve the required elastic modulus and loss factor at specific temperatures and frequencies, thus achieving good vibration isolation performance. However, for vibrations in the ultra-low frequency range, existing rubber damping materials and other vibration isolation components cannot effectively isolate them. As requirements for vibration environments, product and structural vibration characteristics become increasingly stringent, traditional passive control can no longer meet current vibration isolation requirements. Summary of the Invention

[0003] The present invention aims to overcome the shortcomings of the prior art and provide a variable cross-section circular ring active vibration isolation element. The variable cross-section circular ring active vibration isolation element can accurately suppress the influence of vibration source on load, thereby improving the accuracy of load system and realizing ultra-low frequency vibration isolation.

[0004] A second objective of this invention is to provide a method for the aforementioned variable cross-section circular ring active vibration isolation element.

[0005] The third objective of this invention is to provide a vibration isolation device that utilizes the aforementioned variable cross-section circular ring active vibration isolation element.

[0006] The technical solution of this invention to solve the problems of the prior art is:

[0007] A variable cross-section circular ring active vibration isolation element includes a variable cross-section circular ring structure, a connecting end face disposed on the variable cross-section circular ring structure, a piezoelectric sheet, an acceleration sensor, and an active vibration reduction control device, wherein...

[0008] The connecting end faces are in two sets, symmetrically arranged on the upper and lower sides of the variable cross-section annular structure; the cross-section of the variable cross-section annular structure is arched, and grooves are provided in the middle of the left and right sides of the variable cross-section annular structure. There are two sets of grooves on each side, and the two sets of grooves are located on the inner and outer sides of the variable cross-section annular structure, respectively. The piezoelectric sheet is installed in the groove; wherein, the piezoelectric sheet on the inner groove is the first piezoelectric sheet, and the piezoelectric sheet on the outer groove is the second piezoelectric sheet.

[0009] The acceleration sensor is installed on the lower end face of the variable cross-section circular ring structure to detect vibration source signals in real time. After analysis and processing by the active vibration reduction control device, a control signal is output to the first piezoelectric element or the second piezoelectric element, causing the first piezoelectric element or the second piezoelectric element to generate the inverse piezoelectric effect, thereby causing the variable cross-section circular ring structure to deform, and in turn causing the upper and lower connecting end faces of the variable cross-section circular ring structure to generate relative displacement, thereby reducing the impact of the vibration source on the load.

[0010] Preferably, the piezoelectric sheet is made of piezoelectric fiber composite material; the piezoelectric fiber composite material is bonded to the corresponding groove by a two-component epoxy resin adhesive.

[0011] Preferably, the arched cross-section of the variable cross-section annular structure is composed of two circular arcs whose centers are on the same line and whose central angles are the same.

[0012] Preferably, the two sets of first piezoelectric sheets located inside the variable cross-section annular structure are connected in series by wires to form a first vibration damping branch; the two sets of second piezoelectric sheets located outside the variable cross-section annular structure are connected in series by wires to form a second vibration damping branch; the first vibration damping branch and the second vibration damping branch are connected in parallel and then connected to the input terminal of the active vibration damping control device.

[0013] Preferably, both the connecting end face and the variable cross-section ring structure are integrally formed using 3D printing technology.

[0014] Preferably, the material used in the 3D printing technology is thermoplastic polyurethane elastomer.

[0015] A method for an active vibration isolation element with variable cross-section circular ring includes the following steps:

[0016] S1, When external vibration occurs, the acceleration sensor installed on the lower end face of the variable cross-section circular ring structure will collect the vibration signal;

[0017] S2, the collected vibration signal is input to the active vibration damping control device in real time. After receiving the vibration signal, the active vibration damping control device performs prediction based on its internally constructed control model, and then outputs a control signal to control the first or second piezoelectric element. The driver achieves a two-stage voltage change in the piezoelectric element, causing it to produce an inverse piezoelectric effect, which induces deformation in the first or second piezoelectric element, thereby preventing further deformation of the variable cross-section circular ring structure.

[0018] When the variable cross-section ring structure is in an upward stretching state, the second piezoelectric sheet that receives the control signal bends and deforms, thereby causing the outer side of the middle part of the variable cross-section ring structure to bend downward, so that the variable cross-section ring structure has a downward compression tendency.

[0019] When the variable cross-section ring structure is in a downward compression state, the first piezoelectric sheet that receives the control signal bends and deforms, thereby causing the inner side of the middle part of the variable cross-section ring structure to bend inward, so that the ring structure has an upward stretching tendency.

[0020] S3. After adjustment, the accelerometer continues to receive the vibration signal generated by the vibration source in real time. The control model of the active vibration reduction control device predicts and adjusts the deformation of the first piezoelectric sheet or the second piezoelectric sheet in real time according to the magnitude of the vibration signal, thereby adjusting the shear and tensile deformation of the variable cross-section ring structure.

[0021] Preferably, in step S2, the accelerometer is used to acquire vibration signals in real time, and the signals are filtered to obtain the vibration amplitude Z and vibration frequency. And phase φ, where the transmissivity is the ratio of the vibration amplitude received by the active vibration reduction control device after vibration isolation to the vibration amplitude of the vibration source; the control model is used to obtain the magnitude of the vibration amplitude Y on the upper end face of the variable cross section circular ring structure under the vibration and the deformation displacement difference X (X=YZ) of the structure.

[0022] By controlling the voltage U across the piezoelectric element through an active vibration damping control device, the piezoelectric element is subjected to bending deformation, resulting in an output force F. c (U) = aU + b, where a and b are constants; when the variable cross-section circular ring structure is subjected to vibration and deformation, the piezoelectric element is bent and deformed by the output voltage U, and the output force F is controlled by the output voltage U. c (U) to overcome the nonlinear elastic force F a (X) and hysteresis damping force F b (X), thereby preventing further deformation of the variable cross-section ring structure, achieving reverse cancellation of vibration, and reducing the vibration on the upper end face; after adjustment, continue to repeat the previous steps to keep the upper end face in a stable state.

[0023] A vibration isolation device includes n vibration isolation modules and n+1 connecting plates, where n is a positive integer; wherein the n+1 connecting plates are coaxial and equidistant, and each vibration isolation module is disposed between two adjacent connecting plates; the vibration isolation module is composed of multiple variable cross-section circular ring active vibration isolation elements connected in parallel.

[0024] Preferably, the connecting plate is flat; the multiple variable cross-section ring structures are arranged in a rectangular array or in a circular array.

[0025] Preferably, the connecting plate is cylindrical; multiple variable cross-section annular structures are evenly distributed on the cylindrical surface and arranged along the radial direction of the cylindrical surface.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. This invention achieves low-frequency vibration isolation by combining piezoelectric sheets with active suppression. It utilizes the inverse piezoelectric effect of piezoelectric composite materials to convert electrical energy into mechanical energy. The tensile and compressive states of the piezoelectric sheets are controlled by an active vibration reduction control device, thereby adjusting the shear and tensile deformation of the variable cross-section circular ring structure. This improves the energy dissipation value of structural vibration and achieves ultra-low frequency vibration isolation.

[0028] 2. This invention uses only a single accelerometer for signal reception. After prediction using the control model of the active vibration reduction control device, the driver outputs a micro-displacement by controlling the two-stage voltage of the first or second piezoelectric element, thereby actively reducing the impact of the lower end face vibration on the load. The control model can calculate the excitation value based on the vibration source signal and then perform real-time adjustment to suppress vibration.

[0029] 3. The present invention uses a variable cross-section circular ring structure as the connection structure between the upper and lower end faces. Different shapes and sizes of the variable cross-section circular ring structure can make the present invention applicable to various vibration conditions, and have better adaptability and reliability. Attached Figure Description

[0030] Figure 1 This is a perspective view of the variable cross-section circular ring active vibration isolation element of the present invention.

[0031] Figure 2 This is a cross-sectional view of a variable cross-section circular ring structure.

[0032] Figure 3 This is a schematic diagram of the compressive deformation of a variable cross-section circular ring structure.

[0033] Figure 4 This is a schematic diagram showing the selected position and compression deformation result of a variable cross-section circular ring structure during compression.

[0034] Figure 5 This is an equivalent schematic diagram of the variable cross-section circular ring active vibration isolation element of the present invention.

[0035] Figure 6 This is a schematic diagram of the stress state of the first piezoelectric element.

[0036] Figure 7 This is a schematic diagram of the force state of the second piezoelectric element.

[0037] Figure 8 This is a dynamic model diagram of the variable cross-section circular ring active vibration isolation element of the present invention.

[0038] In the figure: 1-Upper end face; 2-Lower end face; 3-Variable cross-section circular ring structure; 4-Piezoelectric sheet; 5-Active vibration damping control device; 6-Acceleration sensor; 7-Outer arc; 8-Inner arc; 9-Variable cross-section circular ring structure before compression deformation; 10-Variable cross-section circular ring structure after compression deformation; 11-Mass block; 12-Equivalent spring; 13-Equivalent damping; 14-Equivalent bending. Detailed Implementation

[0039] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0040] Example 1

[0041] See Figures 1-7 The variable cross-section circular ring active vibration isolation element of the present invention includes a variable cross-section circular ring structure 3, a connecting end face disposed on the variable cross-section circular ring structure, a piezoelectric sheet 4, an acceleration sensor 6, and an active vibration reduction control device 5; the connecting end face is in two sets, and the two sets of connecting end faces are symmetrically disposed on the upper and lower sides of the variable cross-section circular ring structure 3, wherein the connecting end face located on the upper side of the variable cross-section circular ring structure 3 is the upper end face 1, and the connecting end face located on the lower side of the variable cross-section circular ring structure 3 is the lower end face 2; the cross-sectional shape of the variable cross-section circular ring structure 3 is arched, composed of two arcs (i.e., outer arc 7 and inner arc 8) with their centers on the same line and their sector central angles being consistent; the variable cross-section circular ring structure 3 is disposed between the upper end face 1 and the lower end face 2; when the upper end face 1 and the lower end face 2 are compressed in the length direction, the variable cross-section circular ring structure 3 compresses and deforms to generate nonlinear stiffness and damping, thereby achieving excellent vibration isolation effect.

[0042] See Figures 1-7 The variable cross-section annular structure 3 has grooves at the middle positions of its left and right sides. There are two sets of grooves on each side, located on the inner and outer sides of the variable cross-section annular structure 3. Piezoelectric sheets 4 are installed in the grooves. The piezoelectric sheet on the inner groove is the first piezoelectric sheet 4b, and the piezoelectric sheet on the outer groove is the second piezoelectric sheet 4a. The first piezoelectric sheet 4b on the inner side of the variable cross-section annular structure 3 is connected in series with a wire to form a first vibration damping branch. The second piezoelectric sheet 4a on the outer side of the variable cross-section annular structure 3 is connected in series with a wire to form a second vibration damping branch. The first and second vibration damping branches are respectively connected to the input end of the active vibration damping control device 5, so as to make active vibration damping and passive vibration damping integrated in form and independent in mechanism, thereby achieving ultra-low frequency vibration damping.

[0043] In this embodiment, the first piezoelectric sheet 4b and the second piezoelectric sheet 4a are made of piezoelectric fiber composite material. The piezoelectric fiber composite material is a completely bubble-free composite material formed by embedding a piezoelectric ceramic plate into fiber reinforced plastic (GRP) and bonding them together. It can achieve rapid, high-precision and repeatable deformation and has strong real-time controllability. The dimensions of the first piezoelectric sheet 4b and the second piezoelectric sheet 4a are slightly smaller than their corresponding grooves, and they are bonded to their corresponding grooves by a two-component epoxy resin adhesive.

[0044] See Figure 3 , Figure 3 The image shows a comparison between 9 and 10 of a variable cross-section circular ring structure before compressive deformation:

[0045] When the upper end face 1 is subjected to force, the external force is transmitted to the variable cross-section ring structure 3, causing the variable cross-section ring structure 3 to be compressed into an elliptical shape. In order to comprehensively analyze the deformation of the cross-section of the variable cross-section ring structure 3 during the compression process, three specific locations (A, B and C) were selected for evaluation.

[0046] See Figure 4 , Figure 4The diagram shows the selected positions and compression deformation results of the cross-section of the variable cross-section ring structure 3 during compression. The cross-section of the variable cross-section ring structure 3 undergoes different deformations at each of its three positions, resulting in nonlinear stiffness characteristics during compression. The stress is mainly distributed at the edges of the outer arc 7 and inner arc 8 of the cross-section. By comparing the shapes of the cross-section before and after compression, it can be clearly seen that the radius of curvature of the cross-section increases, and the shape continuously approaches a flat rectangle (position A). This deformation reduces the area moment of inertia of the cross-section, thereby reducing its resistance to bending moments. As the cross-sectional shape of the variable cross-section ring structure 3 continuously approaches a rectangle, it is easier to compress compared to the previous moment. This characteristic also makes the variable cross-section ring structure 3 have high stiffness in the early stage of compression, enabling it to support heavy loads. At the static equilibrium point, the variable cross-section ring structure 3 maintains low stiffness characteristics while possessing high load-bearing capacity. Throughout the vibration process, the cross-sectional shape of the variable cross-section ring structure 3 continuously changes, causing the convex surface (outer surface of the cross-section ring structure 3) to stretch outward and the concave surface (inner surface of the cross-section ring structure 3) to compress inward. The resulting tensile and compressive stresses are transformed into nonlinear elastic forces in the variable cross-section ring structure 3 during the reciprocating linear motion. Evaluation of the cross-sectional deformation at three points on the variable cross-section ring structure 3 reveals that the main deformation occurs at point A in the middle portion of the variable cross-section ring structure 3; therefore, grooves are provided both inside and outside point A. Furthermore, the variable cross-section ring structure 3 of this invention utilizes the characteristics of its deformable cross-section during compression to generate geometrical nonlinear stiffness, achieving excellent vibration isolation performance, which is highly advantageous for active vibration reduction of structures.

[0047] When external vibrations occur, the accelerometer 6 fixed to the lower end face 2 of the variable cross-section ring structure 3 collects the vibration signal. After analysis and processing, the signal is input to the active vibration reduction control device 5 in real time. After receiving the vibration signal, the active vibration reduction control device 5 outputs a control signal to the piezoelectric element 4 after prediction by the control model. The driver realizes the two-stage voltage change of the piezoelectric element 4, generating the inverse piezoelectric effect, which converts electrical energy into mechanical energy, thereby causing the piezoelectric element 4 to deform. This, in turn, drives the variable cross-section ring structure 3 to deform, realizing the relative movement of the upper and lower end faces (upper end face 1 and lower end face 2) of the variable cross-section ring structure 3, reducing the impact of the vibration on the lower end face 2 on the upper platform of the base.

[0048] The following are the specific implementation methods:

[0049] See Figures 1-7 The variable cross-section ring structure 3 is connected to the load through the upper end face 1 and to the vibration source through the lower end face 2. The nonlinear stiffness generated by the compression deformation of the variable cross-section ring structure 3 reduces the vibration between the vibration source and the load.

[0050] See Figures 1-7 The acceleration sensor 6 is installed on the lower end face 2 of the variable cross-section circular ring structure 3 and is used to detect the vibration signal received by the lower end face 2 in real time.

[0051] See Figures 1-7 The active vibration damping control device 5 is connected to the acceleration sensor 6 and is used to receive the detection signal from the acceleration sensor 6. After analysis and processing, it sends a control command to the piezoelectric element 4.

[0052] See Figures 1-7 The piezoelectric sheet 4 is attached to the groove on the variable cross-section ring structure 3. According to the control command of the active vibration reduction control device 5, the output voltage drives the piezoelectric sheet 4 to produce the inverse piezoelectric effect, so that the piezoelectric sheet 4 deforms and changes the deformation of the variable cross-section ring structure 3, thereby driving the upper end face 1 and the lower end face 2 to move relative to each other, thereby reducing the vibration of the vibration source on the load.

[0053] In this embodiment, the variable cross-section circular ring vibration isolation element can be integrally molded using 3D printing technology, wherein the material used for 3D printing is thermoplastic polyurethane elastomer. Compared with other vibration damping platforms, the variable cross-section circular ring structure in this invention can adopt an integrated design, greatly reducing the impact of gaps caused by parts assembly on the platform's vibration damping effect. Simultaneously, the piezoelectric fiber composite material can achieve rapid, high-precision, and repeatable deformation, meeting the system's requirements for actuators under various vibration environments. Furthermore, the piezoelectric fiber composite material is divided into a convex piezoelectric fiber composite material (i.e., the second piezoelectric sheet 4a) and a concave piezoelectric fiber composite material (i.e., the first piezoelectric sheet 4b).

[0054] Finally, to avoid coupling between multiple channels and increase control difficulty, only 4 piezoelectric fiber composite materials are provided on the variable cross-section ring structure 3, so as to place the control points in the locations with larger structural deformations as much as possible.

[0055] See Figures 1-7 The variable cross-section circular ring active vibration isolation method of the present invention includes the following steps:

[0056] Step 1: When external vibration occurs, the accelerometer 6 installed on the lower end face 2 of the variable cross-section circular ring structure 3 collects the vibration signal.

[0057] Step 2: The collected vibration signal is input to the active vibration damping control device 5 in real time. After receiving the vibration signal, the active vibration damping control device 5 performs prediction based on its internally constructed control model, and then outputs a control signal to control the first piezoelectric element 4b or the second piezoelectric element 4a. The driver achieves a two-stage voltage change in the piezoelectric element 4, causing it to generate an inverse piezoelectric effect, which induces deformation of the first piezoelectric element 4b or the second piezoelectric element 4a, thereby preventing further deformation of the variable cross-section circular ring structure 2.

[0058] When the variable cross-section annular structure 3 is in an upward stretching state, the second piezoelectric piece 4a, which receives a control signal, bends and deforms, thereby causing the outer side of the middle part of the variable cross-section annular structure 3 to bend downward, so that the variable cross-section annular structure 3 has a downward compression tendency.

[0059] When the variable cross-section annular structure 3 is in a downward compression state, the first piezoelectric piece 4b, receiving a control signal, bends and deforms, thereby causing the inner surface of the middle part of the variable cross-section annular structure 3 to bend inward, giving the variable cross-section annular structure 3 an upward stretching tendency; according to Figure 4 As can be seen, with the compression of the variable cross-section annular structure 3, its intermediate cross-section A gradually approaches a flat rectangle. Therefore, in order to prevent it from becoming a rectangle, it needs to be compressed inward to prevent further deformation. Here, the first piezoelectric piece 4b is placed horizontally, unlike the second piezoelectric piece 4a which is placed vertically.

[0060] Step 3: After adjustment, the accelerometer 6 continues to receive the vibration signal generated by the vibration source in real time. The control model of the active vibration reduction control device 5 predicts and adjusts the deformation of the first piezoelectric sheet 4b or the second piezoelectric sheet 4a in real time according to the magnitude of the vibration signal, thereby adjusting the shear and tensile deformation of the variable cross-section ring structure 2.

[0061] Specifically, the vibration isolation principle for step 2 is as follows:

[0062] like Figure 8 As shown, a single-degree-of-freedom vibration isolation element consists of harmonic excitation, a variable cross-section circular ring active vibration isolation element, and a mass block. Based on the principle of nonlinear dynamics, the vibration isolation element is simplified into a dynamic model of nonlinear elastic force and hysteretic damping force. Where Z and Y represent the harmonic excitation and mass displacement, respectively, and M represents the mass. F b (X) and F c (U) represents the nonlinear elastic force function, the hysteresis damping force function, and the bending output force function, respectively, where X is the displacement difference between the harmonic excitation and the mass displacement, i.e., X = YZ; U is the voltage across the piezoelectric element; It is the first derivative of X with respect to time t. It is the second derivative of X with respect to time t.

[0063] The differential equations of motion of the system are solved using the Lagrange method:

[0064]

[0065] Where d is the differential operator, is the partial differential operator, t is time, and D is the non-conservative generalized force. L is the first derivative of Y with respect to time t, where L = TV, and the total kinetic energy of the system is T and the total potential energy of the system is V.

[0066] Solving the differential equations of motion for this system yields:

[0067]

[0068] in, This is the second derivative of Z with respect to time t. Based on the above function model, the displacement transmissibility of the vibration isolation element can be calculated using the harmonic balance method. For the vibration experienced by the lower end face 2, the accelerometer 6 will collect the vibration signal in real time. After filtering, the vibration amplitude Z and vibration frequency of the signal are obtained. And phase φ. Wherein, transmissibility is defined as the ratio of the vibration amplitude transmitted to the device after vibration isolation to the vibration amplitude of the vibration source. The control model constructed in this invention can, according to the built-in algorithm, obtain the magnitude of the vibration amplitude Y on the upper end face 1 of the vibration isolation element under this vibration and the structural deformation displacement difference X.

[0069] At this time, the active vibration damping control device 5 outputs the voltage U across the piezoelectric element 4, causing the piezoelectric element 4 to bend and deform, outputting a force F. c (U) = aU + b (where a and b are constants). When the variable cross-section circular ring structure is subjected to vibration and deforms, the piezoelectric element 4 is controlled by the output voltage U to bend and deform, outputting a force F. c (U), overcoming the nonlinear elastic force F a (X) and hysteresis damping force F b (X), thereby preventing further deformation of the variable cross-section circular ring structure 3, achieving reverse cancellation of vibration, and reducing the vibration experienced by the upper end face 1. After adjustment, the previous steps are repeated to keep the upper end face 1 in a stable state.

[0070] Example 2

[0071] The vibration isolation device of the present invention includes n vibration isolation modules and n+1 connecting plates, where n is a positive integer; wherein, the n+1 connecting plates are coaxial and equidistant, and each vibration isolation module is respectively disposed between two adjacent connecting plates; the vibration isolation module is composed of multiple variable cross-section circular ring active vibration isolation elements connected in parallel.

[0072] The connecting plate is flat; the multiple variable cross-section ring structures are arranged in a rectangular array or a circular array; or the connecting plate is cylindrical; the multiple variable cross-section ring structures are evenly distributed on the cylindrical surface and arranged along the radial direction of the cylindrical surface.

[0073] The vibration isolation device of the present invention can be specifically implemented with reference to the vibration isolation device disclosed in the invention patent application with application publication number CN 116104905A, which is "an elastic circular ring vibration isolation element with an arched cross section and a vibration isolation device".

[0074] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A variable cross-section circular ring active vibration isolation element, characterized in that, It includes a variable cross-section circular ring structure, a connecting end face disposed on the variable cross-section circular ring structure, a piezoelectric sheet, an acceleration sensor, and an active vibration damping control device, wherein, The connecting end faces are in two sets, symmetrically arranged on the upper and lower sides of the variable cross-section annular structure, with the upper end face located on the upper side and the lower end face located on the lower side. The cross-section of the variable cross-section annular structure is arched, and grooves are provided in the middle of the left and right sides of the variable cross-section annular structure. There are two sets of grooves on each side, located on the inner and outer sides of the variable cross-section annular structure, respectively. The piezoelectric sheet is installed in the groove. The piezoelectric sheet in the inner groove is the first piezoelectric sheet, and the piezoelectric sheet in the outer groove is the second piezoelectric sheet. The acceleration sensor is installed on the lower end face of the variable cross-section circular ring structure to detect vibration source signals in real time. After analysis and processing by the active vibration reduction control device, a control signal is output to the first piezoelectric element or the second piezoelectric element, causing the first piezoelectric element or the second piezoelectric element to generate the inverse piezoelectric effect, thereby driving the variable cross-section circular ring structure to deform, and then driving the connection end faces of the upper and lower sides of the variable cross-section circular ring structure to generate relative displacement, thereby reducing the influence of the vibration source on the load. When the variable cross-section circular ring structure is subjected to vibration and deforms, the piezoelectric sheet is controlled by the output voltage to bend and deform, thereby overcoming the nonlinear elastic force and hysteresis damping force, thus preventing further deformation of the variable cross-section circular ring structure and achieving reverse cancellation of vibration. When the variable cross-section ring structure is in an upward stretching state, the second piezoelectric sheet, which receives a control signal, bends and deforms, thereby causing the outer surface of the middle part of the variable cross-section ring structure to bend downward, giving the variable cross-section ring structure a downward compression tendency; when the variable cross-section ring structure is in a downward compression state, the first piezoelectric sheet, which receives a control signal, bends and deforms, thereby causing the inner surface of the middle part of the variable cross-section ring structure to bend inward, giving the ring structure an upward stretching tendency.

2. The variable cross-section circular ring active vibration isolation element according to claim 1, characterized in that, The piezoelectric sheet is made of piezoelectric fiber composite material; the piezoelectric fiber composite material is bonded to the corresponding groove by a two-component epoxy resin adhesive.

3. The variable cross-section circular ring active vibration isolation element according to claim 1, characterized in that, The arched cross-section of the variable cross-section circular ring structure is composed of two circular arcs whose centers are on the same line and whose central angles are the same.

4. The variable cross-section circular ring active vibration isolation element according to claim 1, characterized in that, Two sets of first piezoelectric sheets located inside the variable cross-section annular structure are connected in series by wires to form a first vibration damping branch; two sets of second piezoelectric sheets located outside the variable cross-section annular structure are connected in series by wires to form a second vibration damping branch; the first vibration damping branch and the second vibration damping branch are connected in parallel and then connected to the input terminal of the active vibration damping control device.

5. The variable cross-section circular ring active vibration isolation element according to claim 1, characterized in that, Both the connecting end face and the variable cross-section ring structure are integrally formed using 3D printing technology.

6. The variable cross-section circular ring active vibration isolation element according to claim 5, characterized in that, The material used in the 3D printing technology is thermoplastic polyurethane elastomer.

7. A method for active vibration isolation of a variable cross-section circular ring used in any one of claims 1-6, characterized in that, Includes the following steps: S1, When external vibration occurs, the acceleration sensor installed on the lower end face of the variable cross-section circular ring structure will collect the vibration signal; S2, the collected vibration signal is input to the active vibration damping control device in real time. After receiving the vibration signal, the active vibration damping control device performs prediction based on its internally constructed control model, and then outputs a control signal to control the first or second piezoelectric element. The driver achieves a two-stage voltage change in the piezoelectric element, causing it to produce an inverse piezoelectric effect, which induces deformation in the first or second piezoelectric element, thereby preventing further deformation of the variable cross-section circular ring structure. When the variable cross-section ring structure is in an upward stretching state, the second piezoelectric sheet that receives the control signal bends and deforms, thereby causing the outer side of the middle part of the variable cross-section ring structure to bend downward, so that the variable cross-section ring structure has a downward compression tendency. When the variable cross-section ring structure is in a downward compression state, the first piezoelectric sheet that receives the control signal bends and deforms, thereby causing the inner side of the middle part of the variable cross-section ring structure to bend inward, so that the ring structure has an upward stretching tendency. S3, the accelerometer continues to receive the vibration signal generated by the vibration source in real time. After prediction by the control model of the active vibration reduction control device, the deformation of the first piezoelectric sheet or the second piezoelectric sheet is adjusted in real time according to the magnitude of the vibration signal, thereby adjusting the shear and tensile deformation of the variable cross-section ring structure.

8. The variable cross-section circular ring active vibration isolation method according to claim 7, characterized in that, In step S2, the accelerometer is used to acquire vibration signals in real time. After filtering by a filter, the vibration amplitude of the vibration signal is obtained. Vibration frequency and phase The transmissibility is the ratio of the vibration amplitude received by the active vibration reduction control device after vibration isolation to the vibration amplitude of the vibration source; the control model is used to obtain the vibration amplitude experienced by the upper surface of the variable cross-section circular ring structure under this vibration. Size and structural deformation displacement difference ,in, ; The voltage across the piezoelectric element is output through the active vibration damping control device. The control allows the piezoelectric element to bend and deform, outputting force. ,in , The voltage is constant; when the variable cross-section circular ring structure is subjected to vibration and deformation, the output voltage is constant. Controlling the output force of piezoelectric element bending deformation To overcome nonlinear elastic forces and hysteresis damping force This prevents further deformation of the variable cross-section ring structure, achieves reverse cancellation of vibration, and reduces the vibration on the upper end face; after adjustment, the previous steps are repeated to keep the upper end face in a stable state.

9. A vibration isolation device, characterized in that, It includes n vibration isolation modules and n+1 connecting plates, where n is a positive integer; wherein the n+1 connecting plates are coaxial and equidistant, and each vibration isolation module is respectively disposed between two adjacent connecting plates; the vibration isolation module is composed of multiple variable cross-section circular ring active vibration isolation elements as described in any one of claims 1-6 connected in parallel.

10. The vibration isolation device according to claim 9, characterized in that, The connecting plate is flat; multiple variable cross-section ring structures are arranged in a rectangular array or in a circular array; or, the connecting plate is cylindrical; multiple variable cross-section ring structures are evenly distributed on the cylindrical surface and arranged along the radial direction of the cylindrical surface.

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