Three-dimensional unit cell type vibration absorber for inhibiting variable flutter during milling of robot and design method of three-dimensional unit cell type vibration absorber

Abstract

The invention belongs to the technical field of robot milling vibration control, and particularly relates to a three-dimensional unit cell type vibration absorber for restraining variable flutter during robot milling and a design method of the three-dimensional unit cell type vibration absorber. The vibration absorber comprises a plurality of magnetic conductive balls, a plurality of magnetorheological elastomers, a magnetic conductive block, an electromagnetic coil, an upper wall, a lower wall and four side walls. The upper wall, the lower wall and the four side walls form a cubic structure, the electromagnetic coil sleeves the outer walls of the four side walls, and the magnetic conductive block sleeves the outer wall of the electromagnetic coil and is connected with the upper wall and the lower wall; the three-dimensional unit cell type vibration absorber is of a central symmetry structure. The plurality of magnetic conductive balls are arranged in the cubic structure according to the form of the body-centered cubic structure, the inner wall of the cubic structure is connected with the magnetic conductive balls, and the magnetic conductive ball located at the body center is connected with the magnetic conductive balls located at the eight vertex angles through the magnetorheological elastomer. The whole structure has three-dimensional symmetry, so that the structure can still keep stable under any rotating posture of the robot, modals of different directions and frequencies of the robot can be restrained, and the restraining effect is good.

Description

Technical Field

[0001] The invention belongs to the technical field of robot milling vibration control, and in particular relates to a three-dimensional cellular vibration absorber for suppressing time-varying chatter of robot milling and a design method thereof. Background Art

[0002] As the demand for processing large components in modern manufacturing increases, robotic milling has been widely used in the field of complex parts processing due to its advantages such as high efficiency, low cost and versatility. However, with the development of robotic milling technology, its limitations have gradually emerged, one of which is the low-frequency flutter problem caused by low structural stiffness.

[0003] Additional vibration absorbers are a common means of suppressing low-frequency chatter in robot milling. Zhang (Mechanical Systems and Signal Processing 2023; 200: 110506) et al. designed a parallel MTMD system to suppress the forced vibration of the parallel machining robot in two feed directions. By using small polymer material springs and viscous fluid damping inside the mass block to form the MTMD system, broadband vibration suppression was achieved in a narrow space. Yuan (Mechanical Systems and Signal Processing 2019; 117: 221-37) et al. proposed the development of a semi-active vibration absorber using magnetorheological elastomer (MRE). MRE is a new type of magnetically controlled material, the magnetic conductive particles inside it will undergo structural changes under the stimulation of an external magnetic field, resulting in changes in the mechanical properties of the material. The designed MRE vibration absorber can cover the vibration frequency variation of 7-20Hz.

[0004] When the robot is performing milling processing, its posture-dependent characteristics cause the low-frequency chatter mode to be time-varying. This time-varying property is not only reflected in the frequency but also in the direction. At present, there are few studies on the suppression device of robot milling chatter that consider the time-varying properties of modal direction and frequency at the same time, and most studies can only suppress two directions. In order to effectively suppress the time-varying chatter of robot milling, higher requirements are put forward for vibration suppression equipment: First, the direction and frequency of the chatter are both time-varying, and it is necessary to develop multi-directional vibration suppression equipment that can change frequency or has wide-band vibration suppression characteristics. Second, the posture of the robot changes continuously during the processing process, especially when the posture changes greatly when processing large parts, and the vibration suppression equipment needs to be able to maintain the original vibration suppression ability under any rotation posture. Summary of the invention

[0005] The purpose of the present invention is to provide a three-dimensional lattice vibration absorber for suppressing time-varying chatter of robot milling and a design method thereof, so as to suppress the modes of the robot in different directions and frequencies and solve the problem of time-varying chatter.

[0006] To achieve the above-mentioned object, the present invention provides a three-dimensional crystal cell vibration absorber for suppressing time-varying chatter of robot milling, comprising a plurality of magnetic conductive balls, a plurality of magnetorheological elastomers, a magnetic conductive block, an electromagnetic coil, an upper and lower wall and four side walls; the upper and lower walls and the four side walls form a cubic structure, the electromagnetic coil is sleeved on the outer walls of the four side walls, the magnetic conductive block is sleeved on the outer wall of the electromagnetic coil and connected to the upper and lower walls; the three-dimensional crystal cell vibration absorber is a centrally symmetrical structure;

[0007] A plurality of magnetically conductive balls are arranged in the cubic structure in the form of a body-centered cubic structure, and the inner wall of the cubic structure is connected to the magnetically conductive balls. The magnetically conductive ball located at the center of the body is connected to the magnetically conductive balls located at the eight vertex corners through the magnetorheological elastomer.

[0008] Furthermore, the magnetorheological elastomer is obtained by mixing and curing carbonyl iron powder, silicone rubber and dimethyl silicone oil in a mass ratio of (1-3):(0.5-1.5):1.

[0009] Furthermore, the magnetorheological elastomers used to connect the magnetic conductive balls in the same layer are connected to each other through the magnetorheological elastomers to form a network structure.

[0010] Furthermore, the magnetic conductive ball is connected to the magnetorheological elastomer by bonding, and the contact surface is in contact with the arc surface of the magnetic conductive ball;

[0011] The magnetic conductive ball is connected to the inner wall of the cubic structure by welding.

[0012] Furthermore, the material of the magnetic conductive ball and the magnetic conductive block is No. 10 steel;

[0013] The side wall is made of non-magnetic aluminum alloy, and the upper and lower walls are made of magnetic conductive material.

[0014] The present invention also provides a method for designing a three-dimensional lattice vibration absorber as described in any one of the above, comprising the following steps:

[0015] S1. Determine the target vibration suppression frequency;

[0016] S2. Preliminary determination of the side length L of the vibration absorber and the number of turns N of the electromagnetic coil coil and an electric current I is passed; the side length L of the vibration absorber refers to the side length of the body-centered cubic structure composed of the magnetic conductive ball and the magnetorheological elastomer in the cubic structure;

[0017] S3. Preliminarily set the initial values ​​of n and γ, and calculate the thickness h and diameter d of the magnetorheological elastomer according to the following formula MRE And the diameter d0 of the magnetic sphere:

[0018] F a =Ncoil I=φR a

[0019] φ=BS

[0020] R a =R1+R2+R MRE

[0021]

[0022] 2πd MRE 2 =γπd0 2

[0023] Where n represents the number of body-centered cubic structure layers contained in each side of the vibration absorber, γ represents the ratio of the total contact area of ​​the eight magnetorheological elastomers and the magnetic sphere to the surface area of ​​the magnetic sphere; F a is the magnetomotive force, φ is the total magnetic flux, B is the magnetic induction intensity, S is the area through which the magnetic field passes, R a is the total magnetic resistance; μ0=4π×10 -7 T·m / A is the vacuum permeability; μ MRE ≈2, is the magnetic permeability of the magnetorheological elastomer;

[0024] S4. Calculate the natural frequency based on the dynamic model according to the design parameters preliminarily determined above;

[0025] S5. Determine whether the natural frequency meets the requirements. If so, the parameters of steps S2 and S3 are the design parameters of the vibration absorber. If not, repeat steps S2-S5 until the optimized vibration absorber design parameters are obtained.

[0026] Furthermore, when determining the side length L, first select a value within 80 to 120 mm, and the number of turns N coil And the current I first flows through N coil The value is within the range of I≤7kA.

[0027] Furthermore, the value range of γ is 0.25 to 0.6; when determining the initial value of n, first determine it within the range of n≤5;

[0028] And / or, the target vibration suppression frequency is 10 to 30 Hz.

[0029] Furthermore, the method for constructing the kinetic model includes:

[0030] (1) Establish the mass matrix of the n-layer three-dimensional crystal cell vibration absorber:

[0031]

[0032] in, ρ and d0 represent the density and diameter of the magnetic sphere, respectively;

[0033] (2) Establish the stiffness matrix K = [Λ ij ] N×N , where Λ ij is a 3×3 matrix, representing the interaction between the i-th magnetic sphere and the j-th magnetic sphere, Λ ij =Λ ji T ;

[0034] (3) Fill the stiffness matrix K according to the different positions of the magnetic ball to obtain the characteristic equation of the multi-degree-of-freedom system:

[0035] det(K-ω 2 M)=0

[0036] Solving the above equation, we get 3N positive real roots, corresponding to the 3N natural angular frequencies of the system, that is, ω1≤ω2≤...≤ω 3N ;

[0037] (4) The three-dimensional unit cell vibration absorber is considered to have the same N-order frequency in three directions, which can be specifically expressed as:

[0038] f X =f Y =f Z =[f1,...,f N ]

[0039] The natural frequency

[0040] Furthermore, different Λ ij The expression is as follows:

[0041]

[0042]

[0043] Among them, Proj represents the interactive projection relationship, D ij is the direction matrix, indicating the direction of interaction, θ and α are the angles between the body diagonal and the side length, and between the face diagonal and the side length of the primitive, respectively; represents the dot product of matrices, is the stiffness of a single columnar MRE; E is the magnetocompression modulus of the columnar MRE.

[0044] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0045] 1. The three-dimensional unit cell vibration absorber provided by the present invention aims at the time-varying characteristics of flutter, and the magnetic balls are stacked in a body-centered cubic form to form a unit cell as the effective mass of the vibration absorber; the magnetic balls are connected by a mesh MRE, and the mesh MRE provides adjustable stiffness for the vibration absorber. The whole structure has three-dimensional symmetry, so that it can remain stable under any rotation posture of the robot.

[0046] 2. The present invention establishes a dynamic model of a three-dimensional crystalline cell vibration absorber, analyzes the influence of various parameters of the vibration absorber on the natural frequency based on the dynamic model, and obtains the design basis for developing the vibration absorber, so that the target vibration absorber can be quickly and reasonably designed according to the target vibration suppression frequency to solve the time-varying characteristics of flutter. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the overall process of designing and applying the three-dimensional cellular vibration absorber of the present invention.

[0048] Figure 2 It is a schematic structural diagram of the three-dimensional cell vibration absorber of the present invention.

[0049] Figure 3 Schematic diagram of the relative position relationship of the balls in the simplified model of the three-dimensional cell vibration absorber.

[0050] Figure 4 Schematic diagram of the simplified model of the magnetic circuit of a three-dimensional cell absorber.

[0051] Figure 5 These are the first-order frequency simulation results of the system under different parameters.

[0052] Figure 6 Schematic diagram of the design process of a three-dimensional cell vibration absorber.

[0053] Figure 7 This is the actual picture of the designed vibration absorber prototype.

[0054] Figure 8 Modal testing of the robot.

[0055] Fig. 9 For robots Figure 8 Direct and crossover frequency responses of the front and rear ends of the additional absorbers in mid-stance 2.

[0056] Fig.10 For robots Figure 8 Direct and crossover frequency responses of the front and rear ends of the additional absorbers in mid-stance 4. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0058] In view of the shortcomings of the prior art in related aspects, the present invention designs a three-dimensional cell-type vibration absorber for suppressing the time-varying vibration of a robot. Figure 1 , showing the specific implementation process: (1) Design of a three-dimensional unit cell vibration absorber structure: In view of the time-varying characteristics of the flutter, the magnetic balls 1 are stacked in a body-centered cubic form to form a unit cell as the effective mass of the vibration absorber; the magnetic balls are bonded with a mesh MRE 2, which provides adjustable stiffness for the vibration absorber. The entire structure has three-dimensional symmetry, which allows it to remain stable under any rotation posture of the robot.

[0059] (2) Conduct dynamic modeling of a three-dimensional lattice vibration absorber: simplify the system into a multi-degree-of-freedom system and establish a dynamic model of the system; then, based on this simulation, the variation law of the natural frequency under various parameters is simulated to obtain the criteria for designing a vibration absorber prototype.

[0060] (3) Design parameters of a three-dimensional lattice vibration absorber and conduct application case verification: Develop a vibration absorber prototype based on the design criteria and vibration suppression objectives, attach the vibration absorber prototype to the robot and conduct dynamic compliance suppression experiments to verify the suppression effect of the prototype.

[0061] The following is a detailed description through specific implementation methods.

[0062] Example 1: Structural design of a three-dimensional cell vibration absorber

[0063] Figure 2The structure of a three-dimensional crystal cell vibration absorber is shown, which consists of a magnetic block 1, a mesh MRE 2, a magnetic ball 3, a coil 4, four side walls 5 and upper and lower walls 6. Among them, the magnetorheological elastomer 2 is a magnetically driven intelligent material, which can achieve changes in its own stiffness by changing the external driving magnetic field. The magnetic balls 3 are stacked in the form of a body-centered cubic structure to form a crystal cell, providing the effective mass of the vibration absorber. Each unit cell contains a magnetic ball 3 at the center of the body and eight magnetic balls 3 at the top corners, wherein the body-center magnetic ball 3 and each magnetic ball 3 at the top corner are connected by the columnar part of the mesh MRE 2 (hereinafter referred to as columnar MRE unless otherwise specified). In order to ensure the three-dimensional symmetry of the overall structure, the side walls 5 and the upper and lower walls 6 are designed as walls with spherical balls, so that the connection between the magnetic balls 3 at the boundary and the wall is consistent with the connection between the magnetic balls 3 inside the unit cell. In order to facilitate the laying of MRE 2 and magnetic balls 3, the columnar MREs of each layer are connected to form a mesh, wherein the columnar parts provide variable stiffness for the structure and the remaining parts only play a connecting role.

[0064] The overall structure is three-dimensionally symmetrical, with the same stiffness and mass in three orthogonal directions. Each magnetic ball 3 is supported by eight surrounding columnar MREs 2, and the contact surface between the magnetic ball 3 and the columnar MREs 2 is an arc surface to ensure the stability of the support, so that the vibration absorber can maintain its vibration suppression capability after rotating at any angle.

[0065] The coil 4 is sleeved on the outer wall of the vibration absorber, wherein the upper and lower walls 6 are made of magnetic conductive material, the wall surface of the side wall 5 is made of non-magnetic aluminum alloy, and the magnetic conductive block 1 is connected to the upper and lower walls 6 of the vibration absorber. The magnetic field passes through the MRE 2 between the magnetic conductive balls 3 inside the vibration absorber in turn, and then returns to the starting point through the upper and lower walls 6 and the magnetic conductive block 1 to form a closed magnetic circuit. When working, the stiffness of the columnar MRE is changed by changing the driving current of the magnetic field, thereby realizing the variable frequency function of the vibration absorber.

[0066] Example 2: Construction of kinetic model

[0067] The n-layer three-dimensional crystal cell vibration absorber has n 3 primitives (including the primitives formed by the magnetic balls on the inner wall of the three-dimensional crystal cell absorber), containing N = n 3 +(n-1) 3 There are magnetic balls (excluding the magnetic balls on the inner wall of the three-dimensional crystal cell absorber), each of which has three degrees of freedom in the X, Y, and Z directions. The system can be regarded as a multi-degree-of-freedom system with 3N degrees of freedom, such as Figure 3 As shown ( Figure 3The magnetic sphere on the inner wall of the three-dimensional cell absorber is not included). Ignoring the influence of gravity, the static equilibrium position of the system is taken as the origin of the generalized coordinate system, and all magnetorheological elastomers (MRE) in the system are in their original state. The mass of each magnetic sphere in the X, Y, and Z directions is the same as m, so the mass matrix of the system is:

[0068]

[0069] in, ρ and d0 represent the density and diameter of the magnetic sphere, respectively.

[0070] According to the D'Alembert principle, the stiffness matrix is ​​established, and the stiffness matrix K = [Λ ij ] N×N , where Λ ij The 3×3 matrix represents the interaction between the i-th magnetic sphere and the j-th magnetic sphere, Λ ij =Λ ji T Different Λ ij The expression is as follows:

[0071]

[0072] Among them, Proj represents the interactive projection relationship, D ij is the direction matrix, indicating the direction of interaction. The specific expression is shown in equations (3)-(4) and Figure 3 , θ and α are the angles between the body diagonal and the side length, and between the face diagonal and the side length of the primitive, respectively; the number of the magnetic ball is Figure 3 It has been noted in; represents the dot product of matrices, is the stiffness of a single columnar MRE, E, d MRE and h represent the magnetocompression modulus, diameter, and thickness of the columnar MRE, respectively.

[0073]

[0074] a, b, c, d, e, f, and g in formula (4) refer to Figure 3 The position of the magnetic ball indicated in .

[0075] Fill the stiffness matrix K according to different positions to obtain the characteristic equation of the multi-degree-of-freedom system:

[0076] det(K-ω 2 M)=0 (5)

[0077] Solving the above equation (det function is used to find the determinant of a square matrix), we get 3N positive real roots, corresponding to the 3N natural angular frequencies of the system, that is, ω1≤ω2≤...≤ω3N Since the system is three-dimensionally symmetrical, each three-order frequency is equal, corresponding to the angular frequency of the system in the X, Y, and Z directions. Therefore, the vibration absorber can be regarded as having the same N-order frequency in the three directions, specifically expressed as f X =f Y =f Z =[f1,...,f N ],in

[0078] The frequency conversion function of the three-dimensional crystal cell vibration absorber is realized by relying on an external driving magnetic field. The present invention adopts an electromagnetic coil to provide a controllable magnetic field. Figure 4 The direction of the magnetic field in the vibration absorber and the corresponding equivalent magnetic circuit diagram are shown, where F a is the total magnetomotive force, N coil is the number of coil turns, I is the input current; R1, R2 and R MRE They are the magnetic resistance of the magnetic block, magnetic ball and MRE respectively. Based on Ohm's law of magnetic circuit, the calculation relationship of the total magnetic circuit can be obtained as follows:

[0079] F a =N coil I=φR a

[0080] φ=BS (6)

[0081] R a =R1+R2+R MRE

[0082] Among them, F a is the magnetomotive force, φ is the total magnetic flux, B is the magnetic induction intensity, S is the area through which the magnetic field passes, R a is the total magnetic resistance.

[0083] The magnetic balls and blocks are made of No. 10 steel, and their relative magnetic permeability is usually above 5000. MRE ≈2. Therefore, the magnetic resistance of the first two is much smaller than that of MRE, so R a ≈R MRE , R MRE The specific expression is as follows:

[0084]

[0085] where μ0 = 4π × 10 -7 T·m / A is the vacuum magnetic permeability, and n·h is the effective magnetic path length of MRE.

[0086] MRE has a good magnetorheological effect when the magnetic field strength is 0.4 T. Taking B = 0.4 T, combining equations (6) and (7) to obtain equation (8), which can be used as a basis for subsequent coil design.

[0087]

[0088] The overall size of the three-dimensional cell absorber is mainly composed of the side length of the cell (expressed by L) and the number of coil turns (expressed by N). coil (expressed), formula (9) is the specific expression of L. When designing, it is hoped that L and N coil The value of is as small as possible. Formula (10) is the relationship between the diameter of MRE and the diameter of the magnetic ball. Considering the support requirements of the columnar MRE for the magnetic ball and the difficulty of demoulding, γ is set to 0.25-0.6.

[0089]

[0090] 2πd MRE 2 =γπd0 2 (10)

[0091] Based on the dynamic model and equations (8) to (10), the change of the first-order frequency f1 of the vibration absorber under different combination parameters can be simulated. Figure 5 a shows that given L and N coil When I, the frequency changes with n and γ. As γ and n increase, the natural frequency increases continuously. When n ≥ 5, the frequency changes slightly with the increase of n. Therefore, n ≤ 5 should be selected in the design. Figure 5 The figure (b) shows that when n and γ are given, the frequency changes with L and N. coil The results show that the natural frequency decreases with the increase of L; coil As I increases, it shows a trend of decreasing first and then increasing, especially when L is small. coil When I>7kA, the frequency increases sharply, so N is selected as much as possible during design. coil I≤7kA.

[0092] Example 3: Example application of three-dimensional cell vibration absorber

[0093] Figure 6 The parameter design process of the three-dimensional lattice vibration absorber is shown. The low-frequency modal coupling vibration frequency of the robot is usually 10-30Hz. Taking this as the design target frequency, the design parameters are shown in Table 1.

[0094] Table 1 Design parameters of three-dimensional cell vibration absorber

[0095]

[0096] Carbonyl iron powder, silicone rubber, and dimethyl silicone oil were mixed and cured in a mass ratio of 2:1:1 to obtain a mesh MRE with the above parameters for the development of the vibration absorber prototype. Figure 7The developed vibration absorber prototype was displayed.

[0097] Robot dynamic compliance suppression experiment

[0098] Modal experiments were carried out on the prototype without vibration absorber and the prototype with vibration absorber under different postures of the robot to verify the suppression effect of the three-dimensional cell vibration absorber on the dynamic compliance of different modes of the robot. Figure 8 The modal test site of SIASUN GCR20-1100 collaborative robot is shown. The robot in different postures is hammered using DYTRAN 3263A2 three-axis accelerometer and PCB 086C03 impulse sledge hammer, and the collected signals are analyzed using m+pVibRunner data acquisition system. Table 2 shows the experimental settings.

[0099] Table 2 Experimental settings

[0100]

[0101] Fig. 9 The direct and cross frequency responses of the robot before and after the vibration absorber is attached in posture 2 are given. The reference coordinate system is the tool coordinate system of the robot end (the tool coordinate system is used as a reference unless otherwise specified in the following text). xy Indicates that the Y direction excites the X direction, and the rest are similar. Select 12Hz and 25Hz as the suppression modes respectively, and adjust the control current of the vibration absorber to suppress different modes. When the current passed through the vibration absorber is 0.3A, the maximum dynamic flexibility of the 12Hz mode decreases from 136μm / N to 25μm / N, and the decrease ratio reaches 82%. Changing the control current of the vibration absorber to 1.9A, the maximum dynamic flexibility of the 25Hz mode decreases from 25.9μm / N to 2.6μm / N, and the decrease ratio reaches 86%. Fig.10 The experimental results in posture 4 are shown. It can be seen that the three-dimensional crystal cell vibration absorber suppresses the robot's maximum dynamic compliance by 71% and 87% in the two modes of 12Hz and 29Hz respectively. The results of the remaining postures are shown in Table 3. The prototype can maintain three-dimensional working stability at different rotation angles at the end of the robot, and the maximum dynamic compliance suppression rate is always maintained above 40%. The experimental results verify the suppression effect of the three-dimensional crystal cell vibration absorber prototype.

[0102] Table 3 Experimental results

[0103]

[0104] In summary, the present invention proposes a three-dimensional lattice vibration absorber structure, which is composed of a mesh MRE and magnetic balls embedded therein in a lattice distribution form. The overall structure is lattice-shaped and has three-dimensional symmetry. It can act in any direction in three-dimensional space and can maintain the vibration suppression ability unchanged after rotation. The present invention performs dynamic modeling on the vibration absorber, analyzes the influence of various parameters on the natural frequency of the vibration absorber, and obtains the design basis for developing a prototype. Finally, a vibration absorber is attached to the end of the robot, and a dynamic flexibility suppression experiment is carried out. The experiment shows that the prototype can suppress modes of different directions and frequencies, verifying the suppression effect and application value of the proposed vibration absorber.

[0105] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional cell vibration absorber for suppressing time-varying chatter in robot milling, characterized in that: It includes a plurality of magnetic balls, a plurality of magnetorheological elastomers, a magnetic block, an electromagnetic coil, an upper and lower wall and four side walls; the upper and lower walls and the four side walls form a cubic structure, the electromagnetic coil is sleeved on the outer wall of the four side walls, the magnetic block is sleeved on the outer wall of the electromagnetic coil and connected to the upper and lower walls; the three-dimensional cellular vibration absorber is a centrally symmetrical structure; A plurality of magnetically conductive balls are arranged in the cubic structure in the form of a body-centered cubic structure, and the inner wall of the cubic structure is connected to the magnetically conductive balls. The magnetically conductive ball located at the body center is connected to the magnetically conductive balls located at the eight vertex corners through the magnetorheological elastomer.

2. The three-dimensional lattice vibration absorber according to claim 1, characterized in that: The magnetorheological elastomer is obtained by mixing carbonyl iron powder, silicone rubber and dimethyl silicone oil in a mass ratio of (1-3):(0.5-1.5):1 and curing.

3. The three-dimensional lattice vibration absorber according to claim 1, characterized in that: The magnetorheological elastomers used to connect the magnetic conductive balls in the same layer are connected to each other through the magnetorheological elastomers to form a network structure.

4. The three-dimensional lattice vibration absorber according to claim 1, characterized in that: The magnetic conductive ball is connected to the magnetorheological elastomer by bonding, and the contact surface is in contact with the arc surface of the magnetic conductive ball; The magnetic conductive ball is connected to the inner wall of the cubic structure by welding.

5. The three-dimensional lattice vibration absorber according to claim 1, characterized in that: The material of the magnetic ball and the magnetic block is No. 10 steel; The side wall is made of non-magnetic aluminum alloy, and the upper and lower walls are made of magnetic conductive material.

6. A design method for a three-dimensional cellular vibration absorber according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Determine the target vibration suppression frequency; S2. Preliminary determination of the side length L of the vibration absorber and the number of turns N of the electromagnetic coil coil and an electric current I is passed; the side length L of the vibration absorber refers to the side length of the body-centered cubic structure composed of the magnetic conductive ball and the magnetorheological elastomer in the cubic structure; S3. Preliminarily set the initial values ​​of n and γ, and calculate the thickness h and diameter d of the magnetorheological elastomer according to the following formula MRE And the diameter d0 of the magnetic sphere: F a =N coil I=φR a φ=BS R a =R1+R2+R MRE 2πd MRE 2 =γπd0 2 Where n represents the number of body-centered cubic structure layers contained in each side of the vibration absorber, γ represents the ratio of the total contact area of ​​the eight magnetorheological elastomers and the magnetic sphere to the surface area of ​​the magnetic sphere; F a is the magnetomotive force, φ is the total magnetic flux, B is the magnetic induction intensity, S is the area through which the magnetic field passes, R a is the total magnetic resistance; μ0=4π×10 -7 T·m / A is the vacuum permeability; μ MRE is the magnetic permeability of the magnetorheological elastomer; S4. Calculate the natural frequency based on the dynamic model according to the design parameters preliminarily determined above; S5. Determine whether the natural frequency meets the requirements. If so, the parameters of steps S2 and S3 are the design parameters of the vibration absorber. If not, repeat steps S2-S5 until the optimized vibration absorber design parameters are obtained.

7. The design method according to claim 6, characterized in that: When determining the side length L, first select a value within 80 to 120 mm, and the number of turns N coil And the current I first flows through N coil The value is within the range of I≤7kA.

8. The design method according to claim 6, characterized in that: The value range of γ is 0.25~0.6; when determining the initial value of n, first determine it within the range of n≤5; And / or, the target vibration suppression frequency is 10 to 30 Hz.

9. The design method according to any one of claims 6 to 8, characterized in that: The method for constructing the kinetic model comprises: (1) Establish the mass matrix of the n-layer three-dimensional crystal cell vibration absorber: in, ρ and d0 represent the density and diameter of the magnetic sphere, respectively; (2) Establish the stiffness matrix K = [Λ ij ] N×N , where Λ ij is a 3×3 matrix, representing the interaction between the i-th magnetic sphere and the j-th magnetic sphere, Λ ij =Λ ji T ; (3) Fill the stiffness matrix K according to the different positions of the magnetic ball to obtain the characteristic equation of the multi-degree-of-freedom system: det(K-ω 2 M)=0 Solving the above equation, we get 3N positive real roots, corresponding to the 3N natural angular frequencies of the system, that is, ω1≤ω2≤...≤ω 3N ; (4) The three-dimensional unit cell vibration absorber is considered to have the same N-order frequency in three directions, which can be specifically expressed as: in X =f Y =f Z =[f1,...,f N ] The natural frequency 10. The design method according to claim 9, characterized in that: Different Λ ij The expression is as follows: Among them, Proj represents the interactive projection relationship, D ij is the direction matrix, indicating the direction of interaction, θ and α are the angles between the body diagonal and the side length, and between the face diagonal and the side length of the primitive, respectively; represents the dot product of matrices, is the stiffness of a single columnar MRE; E represents the magneto-compression modulus of the columnar MRE; a, b, c, d, e, f, g represent the magnetic conductive spheres at the eight corners of the body-centered cubic structure.

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