Three-degree-of-freedom micro-vibration isolator with stiffness and damping self-adaptive cooperative regulation and control function

Abstract

The invention discloses a three-degree-of-freedom micro-vibration isolator with stiffness and damping self-adaptive cooperative regulation and control functions, belongs to the technical field of precise vibration isolation, and can realize three-degree-of-freedom near-full-frequency-band vibration isolation performance under variable loads. Comprising an upper plate, a base plate and three sets of low-frequency vibration isolation dampers connected with the upper plate and the base plate. According to a negative stiffness damping regulator in the low-frequency vibration isolation damper, a single-side high-flux-density excitation magnetic field is constructed by means of multiple layers of uniform-section magnetic ring arrays which are arranged in an array mode in the axial direction and are vertically magnetized between the adjacent layers, a vertically magnetized fixed magnetic ring array and a vertically magnetized movable magnetic ring array are coaxially nested to generate the high negative stiffness characteristic, and the vertically magnetized fixed magnetic ring array and the vertically magnetized movable magnetic ring array are coaxially nested with a coil to generate the high damping characteristic; by sensing the vibration isolation load mass or excitation frequency change in real time, the magnitude of current in an electrified coil is adjusted, precise and controllable excitation magnetic flux is generated, the negative stiffness and damping requirements of near-full-band vibration isolation are met, and the multi-azimuth, near-full-band and high-performance vibration isolation effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of precision vibration isolation, in particular to a three-degree-of-freedom micro-vibration isolation device with adaptive coordinated regulation of stiffness and damping. Background Art

[0002] Low-frequency micro-vibration interference in the environment has become one of the key issues that restrict the improvement of precision in the installation, adjustment, testing and experiment of precision instruments and equipment. Equipping precision instruments and equipment with low-frequency vibration isolation platforms has gradually become the main technical means to suppress environmental micro-vibrations in the field of ultra-precision engineering. Stiffness and damping are the core parameters that determine the vibration isolation bandwidth and vibration isolation effect. They are directly related to the effect of the micro-vibration isolation platform on vibrations of different frequencies. How to effectively regulate them is the key to improving vibration isolation performance. At present, research on vibration isolation technology at home and abroad mainly focuses on single-degree-of-freedom systems, focusing on the exploration of unidirectional adjustability of stiffness or damping.

[0003] However, in actual engineering applications, the three-degree-of-freedom vibration isolation system is particularly important because it can more comprehensively cope with complex spatial vibration environments, but research in this field is relatively scarce. Therefore, how to break through the limitations of existing technologies and achieve integrated coordinated regulation of vibration isolation stiffness and damping has become a key bottleneck in achieving high-performance vibration isolation in the near-full frequency band and meeting high-precision requirements. Integrated coordinated regulation of vibration isolation stiffness and damping means that in a dynamically changing environment, the system can intelligently and in real time adjust stiffness and damping parameters to achieve the optimal vibration suppression effect.

[0004] China Construction Eighth Engineering Bureau Co., Ltd. (1. "A prefabricated magnetic negative stiffness viscous damper", application number CN202310292721.3; 2. "A self-resetting SMA negative stiffness viscous damper", application number CN202320593107.6, a prefabricated magnetic negative stiffness viscous damper;) discloses a negative stiffness damper consisting of three magnetic negative stiffness structures arranged in an attractive manner and a viscous liquid. The technical solution is characterized in that: (1) the direction in which the negative stiffness and damping of this structure are generated is limited to a single degree of freedom and is not adjustable, making it difficult to effectively isolate multiple directions. (2) The negative stiffness structure is composed of a permanent magnet piston and upper and lower fixed permanent magnets with the same magnetization direction. The excitation magnetic field formed by the upper and lower fixed permanent magnets is symmetrical about its height center, but only the magnetic field close to the piston side produces negative stiffness characteristics. The other side has a lot of leakage magnetic flux, the magnetic field utilization rate is low, and the negative stiffness value generated is limited, which has little effect on the stiffness of heavy load or high-frequency vibration isolation system; (3) The damping characteristics come from the damping force generated by the viscous liquid flowing through the gap between the piston and the cylinder when the permanent magnet piston moves, converting the vibration energy into heat energy. The properties of viscous liquid are unstable and easily affected by external environmental factors such as temperature and humidity. In high or low temperature environments, its damping performance may change, and it may even fail to work normally, affecting the damping effect and service life.

[0005] Patent No. 201410399913.5 discloses a magnetic negative stiffness damper, which uses the relative movement of one or more pairs of axially magnetized first permanent magnets and second magnets to generate negative stiffness characteristics, and uses the relative movement of the first magnet and the conductive tube to form eddy current damping. The characteristics of this technical solution are: (1) It is difficult for a single-degree-of-freedom magnetic negative stiffness damper to effectively isolate multi-directional vibration interference, and it lacks the ability to adaptively adjust with changes in load mass and excitation frequency; (2) The magnetic field utilization rate is low, and the negative stiffness and damping values ​​generated are limited, and the effect on the stiffness and damping of heavy-load or high-frequency vibration isolation systems is not significant.

[0006] Patents CN202011189248.9, CN201610915703.6, CN201610834355.X, CN201510395953.7, CN201810300899.7, CN201811101215.7 and CN202311199383.5 all disclose multi-degree-of-freedom vibration isolators. The above technical solutions are characterized in that: (1) for a magnetic ring uniformly magnetized in the radial or axial direction, the excitation magnetic field generated is only utilized on one side, the magnetic field utilization rate is low, the negative stiffness value generated is limited, and the stiffness of the heavy-load or high-frequency vibration isolation system is not effective; (2) it only has the stiffness control function, but cannot adjust the vibration isolation damping, which limits the improvement of the vibration attenuation rate and makes it difficult to achieve high-performance attenuation of full-band vibration.

[0007] In summary, how to design a three-degree-of-freedom micro-vibration isolator that can adaptively and collaboratively control the vibration isolation stiffness and damping through the innovation of vibration isolation structure and principle, which can sense the changes of load mass and external excitation frequency in real time, and adjust the vibration isolation stiffness and damping accordingly, so as to achieve precise coordination between the two, thereby achieving high-performance vibration isolation effect in nearly full frequency band in multiple dimensions. This innovation not only effectively isolates the potential interference of environmental micro-vibration on precision instruments and equipment, but also provides a more stable and reliable operating environment for high-precision assembly, testing and experimental work, which has far-reaching strategic significance for promoting scientific and technological progress and accelerating industrial upgrading. Summary of the invention

[0008] In view of the problem that the existing three-degree-of-freedom vibration isolators cannot take into account the coordinated adaptive regulation of stiffness and damping, and it is difficult to isolate environmental micro-vibration interference in multiple directions, nearly full-band, and with high efficiency, the present invention proposes a three-degree-of-freedom micro-vibration isolator with adaptive coordinated regulation of stiffness and damping, which is composed of an upper plate, a base plate, and three sets of low-frequency vibration isolation dampers connecting the two. The negative stiffness damping controller in the low-frequency vibration isolation damper uses multiple layers of equal-section magnetic ring arrays arranged in an axial array and vertically magnetized between adjacent layers to construct a unilateral high-magnetic density excitation magnetic field, and coaxially nests the vertically magnetized fixed magnetic ring array with the moving magnetic ring array to produce high negative stiffness characteristics, and coaxially nests with the coil to produce adjustable high damping characteristics. By real-time sensing of changes in the vibration isolation load mass or the excitation frequency, the magnitude of the current in the energized coil is adjusted to generate a precisely controllable excitation flux, matching the negative stiffness and damping requirements of near full-band vibration isolation, and achieving multi-directional, near full-band and high-performance vibration isolation effects.

[0009] The technical solution of the present invention is:

[0010] A three-degree-of-freedom micro-vibration isolation device with adaptive coordinated regulation of stiffness and damping comprises an upper plate, a base plate and three sets of low-frequency vibration isolation dampers connecting the two. The upper plate has the degree of freedom of translation along the vertical z-axis and the degree of freedom of rotation around the horizontal x-axis and y-axis relative to the base plate. The top of each set of low-frequency vibration isolation dampers is connected to the fixing part at the bottom of the upper plate through an upper flexible hinge, and the connection points are evenly distributed at intervals of 120° along the circumference of the upper plate; the bottom of each set of low-frequency vibration isolation dampers is connected to the fixing part at the top of the base plate through a lower flexible hinge, and the connection points are evenly distributed at intervals of 120° along the circumference of the base plate; the low-frequency vibration isolation damper is composed of a coil spring and a negative stiffness damping controller in parallel, and the negative stiffness damping controller comprises a fixed magnetic ring array, a fixed magnetic array fixing part, a moving magnetic ring Array, moving magnetic array connector, coil, coil skeleton, sensor, signal conditioner, collector, controller, driver, upper connector and lower connector, fixed magnetic array fixture, fixed magnetic ring array, moving magnetic array connector, moving magnetic ring array, coil skeleton and coil are coaxially nested, arranged with gaps from the axis along the radius outward, and the overall structure is axially symmetrical; the fixed magnetic array fixture is a cylindrical structure with an inverted T-shaped cross-section, the bottom of which is fixedly connected to the coil skeleton by a thread, and the top maintains a certain gap with the moving magnetic array connector; the fixed magnetic ring array is coaxially nested, tightly matched, and fixedly installed on the outer side of the fixed magnetic array fixture, and has gaps with the moving magnetic array connector in the radial and axial directions; the moving magnetic array connector is an annular sleeve, the top of which is connected to the moving magnetic array fixture by a thread. The upper connecting piece is fixedly connected, an annular boss is arranged at the bottom, and an annular groove is arranged in the boss; the spiral spring is coaxially nested with the dynamic magnetic array connecting piece and the coil skeleton, and its top end is fixedly installed in the annular groove at the bottom of the dynamic magnetic array connecting piece, and the bottom is fixedly installed in the annular groove on the bottom surface of the coil skeleton; the dynamic magnetic ring array is coaxially nested, tightly matched, and fixedly installed on the outer side of the dynamic magnetic array connecting piece, and a gap is arranged radially with the coil skeleton; the fixed magnetic ring array and the dynamic magnetic ring array are both composed of multiple layers of equal-section magnetic rings arranged in an axial array and magnetized vertically between adjacent layers, wherein the heights of the odd-numbered layers of magnetic rings are equal, and the heights of the even-numbered layers of magnetic rings are equal; the first layer of magnetic rings of the fixed magnetic ring array and the dynamic magnetic ring array are magnetized in opposite directions along the radial direction, and on the right half of the front section view With each additional layer, the magnetization direction of the fixed magnetic ring rotates 90° clockwise, and the magnetization direction of the moving magnetic ring rotates 90° counterclockwise; the coil skeleton is an annular sleeve with deep grooves on the outer side along the circumference, the top of which maintains a certain gap with the upper flexible hinge, and the bottom is fixedly connected to the lower connecting piece through a thread; the coil is coaxially nested, tightly fitted, and fixedly installed on the outer side of the coil skeleton, the coil is connected to the output end of the driver, and the input end of the driver is connected to the output end of the controller through a serial port or a network. The controller integrates a control algorithm based on acceleration and velocity composite feedback, and its input end reads the information of the collector through a serial port or a network, the input end of the collector is connected to the output end of the signal conditioner, and the input end of the signal conditioner is connected to the sensor.

[0011] Preferably, the number of layers of the fixed magnetic ring array and the dynamic magnetic ring array is 2n+1, where n≥1, n∈N + .

[0012] Preferably, the heights of the magnetic rings in the same layer of the fixed magnetic ring array and the moving magnetic ring array are equal.

[0013] Preferably, the bottom surface of the first layer of magnetic rings in the fixed magnetic ring array overlaps with the bottom surface of the first layer of magnetic rings in the moving magnetic ring array.

[0014] Preferably, the height of the coil is equal to the height of the fixed magnetic ring array, and is symmetrical about the axial height center of the fixed magnetic ring array.

[0015] Preferably, the driver is a linear regulator, a linear driver, a switching regulator or a switching driver.

[0016] Preferably, the radially magnetized magnetic rings in the fixed magnetic ring array and the moving magnetic ring array are composed of a plurality of tile-shaped magnets uniformly magnetized in the radial direction, the number of tile-shaped magnets can be 4, 5, 6, 8, 10, 12 and 15, and the gap between adjacent tile-shaped magnets does not exceed 3°.

[0017] Preferably, the sensor is a single three-degree-of-freedom velocity sensor or acceleration sensor, or a sensor group consisting of a velocity sensor or acceleration sensor with one translational degree of freedom and two rotational degrees of freedom.

[0018] Preferably, the signal conditioner includes an amplifier and a filter, the gain and bandwidth of the amplifier are adjustable, the filter can realize a high-pass filtering function, and its cut-off frequency is adjustable.

[0019] Preferably, the fixed magnetic array fixing part, the dynamic magnetic array connecting part, the upper connecting part, the lower connecting part, the upper flexible hinge, the lower flexible hinge and the coil spring are made of non-magnetic or weakly magnetic aluminum alloy, titanium alloy or austenitic stainless steel.

[0020] Preferably, the coil skeleton is made of ceramic, granite, fiberglass or hard plastic.

[0021] The technical innovation and good effects of the present invention are:

[0022] (1) This technical solution uses the vertical magnetization of the fixed magnetic ring array and the dynamic magnetic ring array to coaxially nest to produce high negative stiffness characteristics, and coaxial nesting with the coil to produce adjustable high damping characteristics, with high magnetic field utilization and low system energy consumption. The low-frequency vibration isolation damper uses 2n+1 (n≥1, n∈N +) layers are arranged in an axial array, and an equal-section magnetic ring array with perpendicular magnetization between adjacent layers constructs a unilateral high magnetic density excitation magnetic field, and the vertically magnetized fixed magnetic ring array and the dynamic magnetic ring array and the coil are coaxially nested to produce high negative stiffness and adjustable high damping characteristics. The unilateral high magnetic density excitation magnetic field can not only effectively weaken the magnetic field strength on the non-working side, but also significantly enhance the magnetic field strength on the working side, improve the negative stiffness and damping value of the low-frequency vibration isolation damper, and expand the vibration isolation frequency band and damping adjustment range. This is one of the innovative points that distinguish the present invention from the prior art.

[0023] (2) This technical solution can sense the fluctuations of load mass and external excitation frequency in real time, and adjust the vibration isolation stiffness and damping accordingly, so as to achieve precise coordination between the two and achieve near full-band and high-performance vibration isolation in three degrees of freedom. The low-frequency vibration isolation damper uses a vertically magnetized fixed magnetic ring array and a dynamic magnetic ring array, and coaxially nested coils to produce high negative stiffness and high damping characteristics; when the load mass changes or the external excitation frequency fluctuates, the sensor instantly captures these dynamic changes and feeds the information back to the controller. The controller integrates a control algorithm based on acceleration and velocity composite feedback, adjusts the current in the coil, and accurately adjusts the vibration isolation stiffness and damping parameters to ensure that the synergy between the two reduces the vibration isolation frequency to near zero frequency when supporting the load platform in parallel with the coil spring, greatly improving the vibration attenuation rate, and thus achieving the optimal state of near full-band high-performance vibration isolation in three degrees of freedom. This is the second innovation of the present invention that distinguishes it from the prior art.

[0024] (3) The present invention achieves coordinated regulation of micro-vibration isolation stiffness and damping parameters by generating adjustable high negative stiffness and low-frequency high damping, as well as high-frequency low damping. By utilizing the dynamic response and coordinated regulation of the stiffness and damping of the coil spring, the stiffness and damping parameters of the near full-band vibration isolation range and the full-frequency high-performance vibration isolation can be matched to maximize the vibration isolation frequency band and vibration isolation effect. This coordinated regulation design effectively avoids the performance bottleneck that may be encountered in single parameter adjustment, and gives the precision vibration isolation system stronger environmental adaptability and dynamic adjustment capabilities, enabling it to flexibly respond to complex scenarios such as changes in load mass, fluctuations in excitation frequency, and diverse vibration isolation requirements. This is the third innovation that distinguishes the present invention from the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A three-dimensional model of a three-degree-of-freedom microvibrator with adaptive coordinated control of stiffness and damping;

[0026] Figure 2 It is the schematic diagram of the arrangement of three sets of low-frequency vibration isolation dampers;

[0027] Figure 3 is a three-dimensional cross-sectional schematic diagram of a low-frequency vibration isolation damper;

[0028] Figure 4It is a front cross-sectional view of the low-frequency vibration isolation damper.

[0029] Description of the part numbers in the figure: 1 substrate, 2 fixed magnetic ring array, 3 fixed magnetic array fixing part, 4 dynamic magnetic ring array, 5 dynamic magnetic array connecting part, 6 coil, 7 coil frame, 8 upper plate, 9 sensor, 10 signal conditioner, 11 collector, 12 controller, 13 driver, 14 negative stiffness damping regulator, 15 coil spring, 161 upper connecting part, 162 lower connecting part, 171 upper flexible hinge, 172 lower flexible hinge, 18 fixing part, 19 low-frequency vibration isolation damper. DETAILED DESCRIPTION

[0030] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0031] A three-degree-of-freedom micro-vibration isolation device with adaptive coordinated regulation of stiffness and damping comprises an upper plate 8, a base plate 1 and three sets of low-frequency vibration isolation dampers 19 connecting the two. The upper plate 8 has the degree of freedom of translation along the vertical z-axis and the degree of freedom of rotation around the horizontal x-axis and y-axis relative to the base plate 1. The top of each set of low-frequency vibration isolation dampers 19 is connected to the fixing member 18 at the bottom of the upper plate 8 through an upper flexible hinge 171, and the connection points are evenly distributed on the upper plate 8 at intervals of 120° along the circumference; the bottom of each set of low-frequency vibration isolation dampers 19 is connected to the fixing member 18 at the top of the base plate 1 through a lower flexible hinge 172, and the connection points are evenly distributed on the base plate 1 at intervals of 120° along the circumference; the characteristics are: the low-frequency vibration isolation dampers 19 are spirally connected to the fixing member 18 at the top of the base plate 1 through a lower flexible hinge 172, and the connection points are evenly distributed on the base plate 1 at intervals of 120° along the circumference; The spring 15 is connected in parallel with the negative stiffness damping regulator 14, and the negative stiffness damping regulator 14 includes a fixed magnetic ring array 2, a fixed magnetic array fixing part 3, a dynamic magnetic ring array 4, a dynamic magnetic array connecting part 5, a coil 6, a coil skeleton 7, a sensor 9, a signal conditioner 10, a collector 11, a controller 12, a driver 13, an upper connecting part 161 and a lower connecting part 162. The fixed magnetic array fixing part 3, the fixed magnetic ring array 2, the dynamic magnetic array connecting part 5, the dynamic magnetic ring array 4, the coil skeleton 7 and the coil 6 are coaxially nested, and are arranged with a gap from the axis along the radius to the outside, and the overall structure is axially symmetrical; the fixed magnetic array fixing part 3 is a cylindrical structure with an inverted T-shaped cross-section, and its bottom is fixedly connected to the coil skeleton 7 by a thread. , a certain gap is maintained between the top and the dynamic magnetic array connector 5; the fixed magnetic ring array 2 is coaxially nested, tightly matched, and fixedly installed on the outer side of the fixed magnetic array fixing part 3, and has gaps with the dynamic magnetic array connector 5 in the radial and axial directions; the dynamic magnetic array connector 5 is an annular sleeve, the top of which is fixedly connected to the upper connector 161 by a thread, and an annular boss is arranged at the bottom, and an annular groove is arranged in the boss; the spiral spring 15 is coaxially nested with the dynamic magnetic array connector 5 and the coil skeleton 7, and the top of the spiral spring 15 is fixedly installed in the annular groove at the bottom of the dynamic magnetic array connector 5, and the bottom is fixedly installed in the annular groove on the bottom surface of the coil skeleton 7; the dynamic magnetic ring array 4 is coaxially nested, tightly matched, and fixedly installed in the dynamic magnetic array connector 5, and there is a gap between the outer side surface and the coil skeleton 7 in the radial direction; the fixed magnetic ring array 2 and the dynamic magnetic ring array 4 are both composed of multiple layers of equal-section magnetic rings arranged in an axial array and magnetized vertically between adjacent layers, wherein the heights of the odd-numbered layers of magnetic rings are equal, and the heights of the even-numbered layers of magnetic rings are equal; the first layer of magnetic rings of the fixed magnetic ring array 2 and the dynamic magnetic ring array 4 are magnetized in the opposite direction in the radial direction, and on the right half of the front cross-sectional view, with each additional layer, the magnetization direction of the fixed magnetic ring rotates 90° clockwise, and the magnetization direction of the dynamic magnetic ring rotates 90° counterclockwise; the coil skeleton 7 is an annular sleeve with deep grooves on the outer side surface along the circumference, the top of which maintains a certain gap with the upper flexible hinge 171, and the bottom is fixedly connected to the lower connecting member 162 by a thread;The coil 6 is coaxially nested, tightly matched, and fixedly installed on the outer side of the coil skeleton 7. The coil 6 is connected to the output end of the driver 13. The input end of the driver 13 is connected to the output end of the controller 12 through a serial port or a network. The controller 12 integrates a control algorithm based on the composite feedback of acceleration and velocity. Its input end reads the information of the collector 11 through a serial port or a network. The input end of the collector 11 is connected to the output end of the signal conditioner 10. The input end of the signal conditioner 10 is connected to the sensor 9. ;

[0032] As a specific implementation, the number of layers of the fixed magnetic ring array 2 and the moving magnetic ring array 4 is 2n+1, where n≥1, n∈N + .

[0033] As a specific implementation manner, the heights of the magnetic rings in the same layer of the fixed magnetic ring array 2 and the moving magnetic ring array 4 are equal.

[0034] As a specific implementation manner, the bottom surface of the first layer of magnetic rings in the fixed magnetic ring array 2 coincides with the bottom surface of the first layer of magnetic rings in the moving magnetic ring array 4 .

[0035] As a specific implementation manner, the height of the coil 6 is equal to the height of the fixed magnetic ring array 2 , and is symmetrical about the axial height center of the fixed magnetic ring array 2 .

[0036] As a specific implementation, the driver 13 is a linear regulator, a linear driver, a switching regulator or a switching driver.

[0037] As a specific implementation method, the radially magnetized magnetic rings in the fixed magnetic ring array 2 and the moving magnetic ring array 4 are composed of multiple tile-shaped magnets that are uniformly magnetized radially. The number of tile-shaped magnets can be 4, 5, 6, 8, 10, 12 and 15, and the gap between adjacent tile-shaped magnets does not exceed 3°.

[0038] As a specific implementation, the sensor 9 is a single velocity sensor or acceleration sensor with three degrees of freedom, or a sensor group consisting of a velocity sensor or acceleration sensor with one translational degree of freedom and two rotational degrees of freedom.

[0039] As a specific implementation, the signal conditioner 10 includes an amplifier and a filter. The gain and bandwidth of the amplifier are adjustable. The filter can realize a high-pass filtering function, and its cut-off frequency is adjustable.

[0040] As a specific implementation, the materials of the fixed magnetic array fixing member 3, the dynamic magnetic array connecting member 5, the upper connecting member 161, the lower connecting member 162, the upper flexible hinge 171, the lower flexible hinge 172 and the coil spring 15 are non-magnetic or weakly magnetic aluminum alloy, titanium alloy or austenitic stainless steel.

[0041] As a specific implementation, the material of the coil skeleton 7 is ceramic, granite, fiberglass or hard plastic.

[0042] Combine the following Figure 1 to Figure 4 An embodiment of the present invention is given.

[0043] like Figure 1 and Figure 2 As shown, the present invention includes an upper plate 8, a base plate 1, and three sets of low-frequency vibration isolation dampers 19 connecting the two. The upper plate 8 has the degree of freedom of translation along the vertical z axis and the degree of freedom of rotation around the horizontal x and y axes relative to the base plate 1. The top of each set of low-frequency vibration isolation dampers 19 is connected to the fixing member 18 at the bottom of the upper plate 8 through four threaded holes evenly distributed on the upper flexible hinge 171, and the connection points are evenly distributed on the upper plate 8 at intervals of 120° along the circumference; the bottom of each set of low-frequency vibration isolation dampers 19 is connected to the fixing member 18 at the top of the base plate 1 through four threaded holes evenly distributed on the lower flexible hinge 172, and the connection points are evenly distributed on the base plate 1 at intervals of 120° along the circumference.

[0044] like Figures 1 to 4As shown, each set of low-frequency vibration isolation damper 19 is composed of a coil spring 15 and a negative stiffness damping regulator 14 in parallel. The negative stiffness damping regulator 14 includes a fixed magnetic ring array 2, a fixed magnetic array fixing part 3, a dynamic magnetic ring array 4, a dynamic magnetic array connecting part 5, a coil 6, a coil skeleton 7, a sensor 9, a signal conditioner 10, a collector 11, a controller 12, a driver 13, an upper connecting part 161 and a lower connecting part 162. The fixed magnetic array fixing part 3, the fixed magnetic ring array 2, the dynamic magnetic array connecting part 5, the dynamic magnetic ring array 4, the coil skeleton 7 and the coil 6 are coaxially nested and arranged from the axis along the radius to the outside. The overall structure is axially symmetrical; the fixed magnetic array fixing part 3 is a cylindrical structure with an inverted T-shaped cross-section, and the material is 7075 aluminum alloy, and its bottom is through Four threaded holes evenly distributed along the circumference are fixedly connected to the coil skeleton 7, and a certain gap is maintained between the top and the dynamic magnetic array connector 5; the fixed magnetic ring array 2 is coaxially nested, tightly matched, and fixedly installed on the outer side of the fixed magnetic array fixture 3, and there are gaps with the dynamic magnetic array connector 5 in the radial and axial directions; the dynamic magnetic array connector 5 is an annular sleeve, made of 7075 aluminum alloy, and its top is fixedly connected to the upper connector 161 through four threaded holes evenly distributed along the circumference, and an annular boss is arranged at the bottom, and an annular groove is arranged in the boss; the spiral spring 15 is coaxially nested with the dynamic magnetic array connector 5 and the coil skeleton 7, and its top is fixedly installed in the annular groove at the bottom of the dynamic magnetic array connector 5, and its bottom is fixedly installed in the annular groove on the bottom surface of the coil skeleton 7. The spiral spring 15 is a left-handed cylindrical spiral spring made of stainless steel, and its positive stiffness characteristics are used to stably support the vibration isolation load. The dynamic magnetic ring array 4 is coaxially nested, tightly matched, and fixedly installed on the outer side of the dynamic magnetic array connector 5, and there are gaps with the coil skeleton 7 in the radial direction. The moving magnetic ring array 4 and the fixed magnetic ring array 2 are both composed of 2n+1 (n≥1, n∈N + ) layers are arranged in an axial array and are composed of equal-section magnetic rings with perpendicular magnetization between adjacent layers. The material of the magnetic rings is N50 brand neodymium iron boron, with a residual magnetic induction intensity of 1.43T and a relative magnetic permeability of 1.03. The inner radius and outer radius of the fixed magnetic ring array 2 are 1.3mm and 6.4mm respectively, the height of the moving magnetic rings of the odd-numbered layers is 2mm, and the height of the moving magnetic rings of the even-numbered layers is 3.4mm. The inner radius and outer radius of the moving magnetic ring array 4 are 7mm and 10mm respectively, the height of the fixed magnetic rings of the odd-numbered layers is 2mm, and the height of the fixed magnetic rings of the even-numbered layers is 3.4mm.

[0045] The first layer of magnetic rings of the fixed magnetic ring array 2 and the moving magnetic ring array 4 are magnetized in opposite directions in the radial direction. On the right half of the front cross-sectional view, with each additional layer, the magnetization direction of the fixed magnetic ring rotates 90° clockwise, and the magnetization direction of the moving magnetic ring rotates 90° counterclockwise; the coil skeleton 7 is an annular sleeve made of 99 alumina ceramic, and a deep groove is provided on its outer side surface along the circumference. A certain gap is maintained between the top and the upper flexible hinge 171, and the bottom is fixedly connected to the lower connecting piece 162 through four threaded holes evenly distributed along the circumference; the coil 6 is formed by winding an insulated copper enameled wire, has a circular cross-section, is coaxially nested, tightly fitted, and fixedly mounted on the outer side of the coil skeleton 7, and the coil 6 is symmetrical about the axial height center of the fixed magnetic ring array 2 and the moving magnetic ring array 4. The coil 6 is connected to the output end of the driver 13, and the input end of the driver 13 is connected to the output end of the controller 12 through a serial port or a network. The controller 12 integrates a control algorithm based on the composite feedback of acceleration and velocity, and its input end reads the information of the collector 11 through a serial port or a network. The input end of the collector 11 is connected to the output end of the signal conditioner 10, and the input end of the signal conditioner 10 is connected to the sensor 9. When the low-frequency vibration isolation damper 19 is working, the sensor 9 will collect the vibration of the vibration isolation load supported by the upper plate 8 in three degrees of freedom in real time. These vibration signals are then processed by the signal conditioner 10, amplified to a detectable electrical signal level, and high-frequency interference and DC bias are filtered out at the same time. The processed signal is transmitted from the collector 11 to the controller 12. After being processed by the control algorithm based on the composite feedback of acceleration and velocity, the controller 12 sends the voltage control signal to the driver 13 through a serial port or a network. The driver 13 converts the received voltage control voltage signal into a corresponding control current and loads it onto the coil 6.

[0046] Since the number of layers of the moving magnetic ring array 4 and the fixed magnetic ring array 2 satisfies 2n+1 (n≥1, n∈N +), and the bottom surface of the first layer of magnetic rings in the fixed magnetic ring array 2 coincides with the bottom surface of the first layer of magnetic rings in the dynamic magnetic ring array 4, so the overall structure of the negative stiffness damping regulator 14 is symmetrical about the n+1th layer of magnetic rings. Under this design, the magnetic force on the dynamic magnetic ring array 4 is zero and is in a balanced state. When the negative stiffness damping regulator 14 is connected in parallel with the coil spring 15, it does not affect the bearing capacity of the coil spring 15. However, under axial micro-disturbance excitation, the dynamic magnetic ring array 4 will move relative to the fixed magnetic ring array 2 and the coil 6. At this time, the axial equilibrium state of the dynamic magnetic ring array 4 is broken, while the radial balance is still maintained. At this time, the axial magnetic force of the fixed magnetic ring array 2 on the dynamic magnetic ring array 4 is the same as the vibration direction, so that it continues to move away from the equilibrium position, and in the absence of external force, the balance cannot be restored by itself, that is, the axial magnetic force of the fixed magnetic ring array 2 on the dynamic magnetic ring array 4 presents a negative stiffness characteristic. This characteristic can regulate the vibration isolation bandwidth of the coil spring 15 by only generating negative stiffness characteristics without affecting the load of the coil spring 15. When the dynamic magnetic ring array 4 moves relative to the coil 6, the magnetic flux passing through the coil 6 changes; under the coupling of the magnetic field and the electric field, the dynamic magnetic ring array 4 will be subjected to a damping force that is positively correlated with the movement speed and in the opposite direction, thereby converting the vibration energy into electrical energy and dissipating it in the form of heat energy.

[0047] The low-frequency vibration isolation damper 19 can sense the fluctuations of the load mass and the external excitation frequency in real time, and adjust the vibration isolation stiffness and damping accordingly, so as to achieve precise coordination between the two and achieve near full-band and high-performance vibration isolation effects. The low-frequency vibration isolation damper 19 uses the vertically magnetized fixed magnetic ring array 2 and the dynamic magnetic ring array 4 and the coil 6 to coaxially nest to produce high negative stiffness and high damping characteristics; when the load mass changes or the external excitation frequency fluctuates, the sensor 9 instantly captures these dynamic changes and feeds the information back to the controller 12. The controller 12 uses a control algorithm based on acceleration and velocity composite feedback to adjust the current in the coil 6, accurately adjust the vibration isolation stiffness and damping parameters, and ensure that the synergy between the two reduces the vibration isolation frequency to near zero frequency when supporting the load platform in parallel with the coil spring 15, greatly improving the vibration attenuation rate, thereby achieving the optimal state of near full-band high-performance vibration isolation in multiple degrees of freedom, and effectively promoting the leapfrog improvement of the accuracy of precision instruments and equipment. Specifically, when the load mass increases, the controller 12 will increase the current in the coil 6 to enhance the axial magnetic force of the negative stiffness damping regulator 14, so that it can provide greater negative stiffness and damping to balance the increased load mass, thereby ensuring that the vibration isolation system can still achieve high performance and near full-band vibration isolation effects under a large load mass. In addition, when the excitation frequency is reduced to a level close to or lower than the natural frequency of the precision micro-vibration isolation system, the controller 12 will adjust the magnitude and direction of the current in the coil 6 to enhance the negative stiffness value of the negative stiffness damping regulator 14, thereby effectively reducing the natural frequency of the vibration isolation, avoiding the resonance area, ensuring that the vibration isolation system is free from resonance interference, and ensuring its long-term stable operation and high reliability.

Claims

1. A three-degree-of-freedom micro-vibration isolation device with adaptive coordinated control of stiffness and damping, comprising an upper plate (8), a base plate (1) and three sets of low-frequency vibration isolation dampers (19) connecting the two, wherein the upper plate (8) has the degree of freedom of translation along the vertical z-axis and the degree of freedom of rotation around the horizontal x-axis and y-axis relative to the base plate (1), the top of each set of low-frequency vibration isolation dampers (19) is connected to a fixing member (18) at the bottom of the upper plate (8) through an upper flexible hinge (171), and the connection points are evenly distributed on the upper plate (8) at intervals of 120° along the circumference; the bottom of each set of low-frequency vibration isolation dampers (19) is connected to a fixing member (18) at the top of the base plate (1) through a lower flexible hinge (172), and the connection points are evenly distributed on the base plate (1) at intervals of 120° along the circumference; characterized in that: The low-frequency vibration isolation damper (19) is composed of a coil spring (15) and a negative stiffness damping regulator (14) connected in parallel. The negative stiffness damping regulator (14) comprises a fixed magnetic ring array (2), a fixed magnetic array fixing member (3), a dynamic magnetic ring array (4), a dynamic magnetic array connecting member (5), a coil (6), a coil skeleton (7), a sensor (9), a signal conditioner (10), a collector (11), a controller (12), a driver (13), an upper connecting member (161) and a lower connecting member (162). The fixed magnetic array fixing member (3), the fixed magnetic ring array (2), the dynamic magnetic array connecting member (5), the dynamic magnetic ring array (4), the coil skeleton (7) and the coil (6) are coaxially nested and arranged with a gap from the axis along the radius outward. The overall structure The fixed magnetic array fixing part (3) is a cylindrical structure with an inverted T-shaped cross section, the bottom of which is fixedly connected to the coil frame (7) by means of a thread, and the top of which maintains a certain gap with the moving magnetic array connecting part (5); the fixed magnetic ring array (2) is coaxially nested, tightly matched, and fixedly installed on the outer side surface of the fixed magnetic array fixing part (3), and has gaps with the moving magnetic array connecting part (5) in both radial and axial directions; the moving magnetic array connecting part (5) is an annular sleeve, the top of which is fixedly connected to the upper connecting part (161) by means of a thread, and an annular boss is arranged at the bottom, and an annular groove is arranged in the boss; the spiral spring (15) is coaxially nested with the moving magnetic array connecting part (5) and the coil frame (7), and the top of which is fixedly installed in the annular groove at the bottom of the moving magnetic array connecting part (5) The bottom is fixedly mounted in an annular groove on the bottom surface of the coil frame (7); the moving magnetic ring array (4) is coaxially nested, tightly matched, and fixedly mounted on the outer side of the moving magnetic array connector (5), and a gap is provided with the coil frame (7) in the radial direction; the fixed magnetic ring array (2) and the moving magnetic ring array (4) are both composed of multiple layers of equal-section magnetic rings arranged in an axial array and magnetized vertically between adjacent layers, wherein the heights of the odd-numbered layers of magnetic rings are equal, and the heights of the even-numbered layers of magnetic rings are equal; the first layer of magnetic rings of the fixed magnetic ring array (2) and the moving magnetic ring array (4) are magnetized in opposite directions in the radial direction, and on the right half of the front cross-sectional view, with each additional layer, the magnetization direction of the fixed magnetic ring rotates 90° clockwise, and the magnetization direction of the moving magnetic ring rotates 90° counterclockwise; the coil frame (7) is an outer side surface along An annular sleeve with deep grooves on its circumference maintains a certain gap between its top and the upper flexible hinge (171), and its bottom is fixedly connected to the lower connecting piece (162) through a thread; the coil (6) is coaxially nested, tightly fitted, and fixedly installed on the outer side of the coil skeleton (7), the coil (6) is connected to the output end of the driver (13), the input end of the driver (13) is connected to the output end of the controller (12) through a serial port or a network, the controller (12) integrates a control algorithm based on acceleration and velocity composite feedback, and its input end reads information from the data collector (11) through a serial port or a network, the input end of the data collector (11) is connected to the output end of the signal conditioner (10), and the input end of the signal conditioner (10) is connected to the sensor (9).

2. The three-degree-of-freedom microvibration isolator with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The number of layers of the fixed magnetic ring array (2) and the dynamic magnetic ring array (4) is 2n+1, where n≥1, n∈N + .

3. The three-degree-of-freedom microvibration isolator with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The heights of the magnetic rings in the same layer of the fixed magnetic ring array (2) and the moving magnetic ring array (4) are equal.

4. The three-degree-of-freedom microvibration isolator with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The bottom surface of the first layer of magnetic rings in the fixed magnetic ring array (2) overlaps with the bottom surface of the first layer of magnetic rings in the moving magnetic ring array (4).

5. The three-degree-of-freedom microvibration isolator with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The height of the coil (6) is equal to the height of the fixed magnetic ring array (2), and is symmetrical about the axial height center of the fixed magnetic ring array (2).

6. The three-degree-of-freedom microvibration isolation device with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The driver (13) is a linear regulator, a linear driver, a switching regulator or a switching driver.

7. The three-degree-of-freedom microvibration isolation device with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The radially magnetized magnetic rings in the fixed magnetic ring array (2) and the moving magnetic ring array (4) are formed by splicing a plurality of tile-shaped magnets uniformly magnetized in the radial direction. The number of tile-shaped magnets can be 4, 5, 6, 8, 10, 12 or 15, and the gap between adjacent tile-shaped magnets does not exceed 3°.

8. The three-degree-of-freedom microvibration isolation device with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The sensor (9) is a single three-degree-of-freedom velocity sensor or acceleration sensor, or a sensor group consisting of a velocity sensor or acceleration sensor with one translational degree of freedom and two rotational degrees of freedom.

9. The three-degree-of-freedom microvibration isolator with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The signal conditioner (10) comprises an amplifier and a filter. The gain and bandwidth of the amplifier are adjustable. The filter can realize a high-pass filtering function and its cut-off frequency is adjustable.

10. The three-degree-of-freedom microvibration isolator with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The fixed magnetic array fixing member (3), the moving magnetic array connecting member (5), the upper connecting member (161), the lower connecting member (162), the upper flexible hinge (171), the lower flexible hinge (172) and the coil spring (15) are made of non-magnetic or weakly magnetic aluminum alloy, titanium alloy or austenitic stainless steel.

11. The three-degree-of-freedom microvibration isolation device with adaptive coordinated control of stiffness and damping according to claim 1, characterized in that: The material of the coil frame (7) is ceramic, granite, glass fiber reinforced plastic or hard plastic.

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