Negative stiffness and damping integrated regulation and control device for large-scale precise micro-vibration isolation

Abstract

The invention discloses a negative stiffness and damping integrated regulation and control device for large precise micro-vibration isolation, and belongs to the technical field of precise vibration isolation. A unilateral high-flux-density excitation magnetic field is constructed by adopting a plurality of layers of uniform-section magnetic ring arrays which are arranged in an array mode in the axial direction and are vertically magnetized between adjacent layers. The vertically magnetized fixed magnetic ring array and the moving magnetic ring array are coaxially nested to realize the high negative stiffness characteristic, and are coaxially nested with the coil to realize the eddy current damping characteristic; under the action of a regulation and control method based on acceleration and speed composite feedback, the characteristics of adjustable high negative stiffness, low-frequency high damping and high-frequency low damping are generated, so that rigidity and damping parameters of near-full-band high-performance vibration isolation are accurately matched with large precise micro-vibration isolation, the vibration isolation performance is maximized, and the stability of a vibration isolation system is improved; and the performance bottleneck of single parameter regulation and control is effectively avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of precision vibration isolation, and in particular to a negative stiffness damping integrated control device for large-scale precision micro-vibration isolation. Background Art

[0002] During the installation, testing and experiment of precision instruments and equipment, low-frequency micro-vibration interference in the environment has become one of the key issues affecting the research effect. Equipping precision instruments and equipment with low-frequency vibration isolators has gradually become the main technical means to suppress environmental micro-vibration in the field of precision engineering. Stiffness and damping are the core parameters that determine the vibration isolation bandwidth and vibration isolation effect, and 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 the vibration isolation performance. However, existing research mainly focuses on small optical micro-vibration isolation platforms and devices. The mass of these platforms and devices is usually within kilograms to hundreds of kilograms, and rarely exceeds the ton level. When facing the stiffness and damping control requirements of large precision micro-vibration isolation platforms of hundreds of tons and above, it is very difficult to generate sufficiently high negative stiffness and damping. In addition, most of the current research focuses on the regulation of a single parameter of stiffness or damping, and it is difficult to achieve the coordinated integrated control effect of stiffness and damping. This limitation makes it difficult for the control strategy to perform at its best in a complex vibration environment and cannot fully meet the high requirements of large precision instrument systems for micro-vibration isolation.

[0003] Patent No. CN201810625715.4 (Chongqing University, "Magnetorheological damper with controllable damping and negative stiffness") discloses a controllable damping and negative stiffness device consisting of a magnetorheological fluid, a rotating piston disposed in a cylinder assembly, and a ball screw pair cooperating with the rotating piston. The shear yield force of the magnetorheological fluid is changed by controlling the current of the excitation coil. While achieving controllable damping force, the moment of inertia is used to achieve controllable negative stiffness of the damper, thereby improving the vibration isolation effect. Patent No. CN201911144675.2 (92578th Unit of the Chinese People's Liberation Army, "A multifunctional composite vibration isolator") discloses a multifunctional composite vibration isolator consisting of an electromagnetic vibration isolator and a magnetorheological damper in parallel. The electromagnetic vibration isolator and the magnetorheological damper are independently fed with specific currents according to the control algorithm. The electromagnetic vibration isolator adopts a magnetic tooth structure. By changing the excitation current, the electromagnetic stiffness can be adjusted online, thereby reducing the vibration isolation natural frequency. The variable damping technology uses magnetorheological dampers, which also achieve variable damping characteristics by changing the input current. The patent number is CN202311509326.2 (Chongqing University, magnetorheological multi-directional broadband vibration absorber). It combines the advantages of magnetorheological dampers and particle dampers, and arranges six magnetorheological dampers between the upper platform and the lower platform in the Stewart platform manner to provide stiffness and damping in multiple directions, broadening the vibration reduction frequency band of traditional tuned mass dampers and effectively solving the traditional particle dampers.

[0004] The above-mentioned magnetorheological damper has the following problems when applied to the field of large-scale precision micro-vibration isolation: 1) The shear yield strength of the magnetorheological damper is low, and it is difficult to produce damping sufficient to regulate large-scale precision micro-vibration isolation of hundreds of tons and above; increasing the damping value by increasing the excitation voltage will increase energy consumption and cost; 2) The properties of magnetorheological fluid are unstable and are 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; 3) Long-term use or improper use may cause residue to form inside the magnetorheological damper, affecting the damping effect and service life.

[0005] Patent No. CN201721249979.1 (Tongji University, "An Electromagnetic Damping Negative Stiffness Bearing") discloses an electromagnetic damping negative stiffness bearing, which uses the electromagnetic force generated by the relative motion of two coaxial magnetic rings magnetized in the same direction to achieve negative stiffness characteristics, and uses the eddy currents generated by cutting the magnetic flux lines when the magnetic rings and the conductor plate move relative to each other to provide damping. The characteristics of this technical solution are: 1) The negative stiffness and damping characteristics are achieved by a split structure, which is relatively complex, not only increasing the material and manufacturing costs, but also difficult to install and maintain; 2) Both the negative stiffness structure and the damping structure are composed of magnetic rings magnetized in a single direction, and the excitation magnetic fields on the inner and outer sides of such magnetic rings are symmetrical. However, in actual applications, only one side of the magnetic field is used and the other side is idle, resulting in low magnetic field utilization of the electromagnetic damping negative stiffness support, and low negative stiffness and damping values, which have little effect on regulating the stiffness and damping of large-scale precision micro-vibration isolation platforms of hundreds of tons and above; 3) After the structural design is completed, the negative stiffness and damping values ​​that can be generated are constant and cannot be adaptively adjusted with changes in load mass, excitation frequency and vibration isolation requirements.

[0006] Professor Cui Junning of Harbin Institute of Technology proposed an ultra-low frequency air spring isolator (Harbin Institute of Technology, "Air spring isolator based on electromagnetic negative stiffness structure", Chinese Patent No.: ZL202010605223.6; 2. Ultra-low frequency isolator based on vertically magnetized magnetic ring negative stiffness structure, ZL202010605241.4; 3. Ultra-low frequency air spring isolator based on axially magnetized magnetic ring negative stiffness structure, ZL202010606309.0; 4. Large-load ultra-low frequency air spring isolator based on negative stiffness magnetic spring, ZL202010605236.3). The device can realize negative stiffness characteristics by using radially reversed magnetization, axially co-magnetized, or inner and outer magnetic rings with perpendicular magnetization, and realize damping effect by using eddy currents and throttle holes generated by the relative motion of the inner and outer magnetic rings. However, after the above device is designed, the negative stiffness and damping value cannot be adjusted, and it can only achieve a specific vibration isolation frequency and vibration attenuation effect under a constant load, and cannot adapt to changes in load mass, excitation frequency and vibration isolation requirements.

[0007] In summary, how to provide a device that can achieve integrated control of large-scale precision micro-vibration isolation stiffness and damping through structural and principle innovation to match the stiffness and damping parameters for achieving near full-band high-performance vibration isolation is of great significance for reducing the interference of environmental micro-vibration on precision instruments and equipment, ensuring the optimal working environment of precision instruments and equipment, and thus improving the accuracy of precision instruments and equipment. This innovation not only helps to ensure the optimization of the working environment of precision instruments and equipment, but also further improves its accuracy, thereby meeting the increasingly stringent needs of scientific research and industrial applications. Summary of the invention

[0008] The present invention aims to solve the problem of insufficient research on stiffness and damping control mechanisms in the current field of large-scale precision micro-vibration isolation, and designs a negative stiffness damping integrated control device for large-scale precision micro-vibration isolation. A single-sided high magnetic density excitation magnetic field is constructed by using a multi-layer axial array arrangement and an equal-section magnetic ring array with vertical magnetization between adjacent layers, and the vertically magnetized fixed magnetic ring array is coaxially nested with the dynamic magnetic ring array to achieve high negative stiffness characteristics, and coaxially nested with the coil to achieve eddy current damping characteristics; under the control method based on acceleration and velocity composite feedback, adjustable high negative stiffness and low-frequency high damping, high-frequency low damping characteristics are generated, thereby accurately matching the stiffness and damping parameters of large-scale precision micro-vibration isolation to achieve near full-band high-performance vibration isolation, maximizing the vibration isolation performance and improving the stability of the vibration isolation system, effectively avoiding the performance bottleneck of single parameter control.

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

[0010] The negative stiffness and damping integrated control device for large-scale precision micro-vibration isolation can generate adjustable high negative stiffness and low-frequency high damping as well as high-frequency low damping characteristics, accurately matching the stiffness and damping parameters of large-scale precision micro-vibration isolation of 100 tons and above to achieve near full-band high-performance vibration isolation, thereby maximizing the vibration isolation bandwidth and vibration isolation effect; it is characterized in that it includes a load platform, a stiffness and damping control device and a large-scale air-floating micro-vibration isolation device; the large-scale air-floating micro-vibration isolation device includes an upper cover plate, an elastic membrane, a cylinder and compressed gas, the upper cover plate is fixedly connected to the load platform, and forms a closed air chamber with the elastic membrane and the cylinder, and compressed gas is introduced into the closed air chamber; the stiffness and damping control device includes a fixed magnetic ring array, a fixed magnetic ring fixing, a dynamic magnetic ring array, The moving magnetic ring fixture, coil, coil skeleton, sensor, signal conditioner, collector, controller and driver, the fixed magnetic ring fixture, the fixed magnetic ring array, the moving magnetic ring array, the moving magnetic ring fixture, the coil skeleton and the coil are coaxially nested and arranged in sequence from the axis along the radius outward; the fixed magnetic ring fixture is a cylindrical structure with an inverted T-shaped cross-section, the bottom of which is fixed, the top of which maintains a gap with the load platform, and a gap is provided with the moving magnetic ring array and the moving magnetic ring fixture along the radial direction; the fixed magnetic ring array is coaxially nested and tightly fixed on the outer side of the fixed magnetic ring fixture, the top of which is pressed and fixed by the fixed magnetic ring positioning piece, and a gap is provided with the moving magnetic ring array and the moving magnetic ring fixture along the radial direction; the moving magnetic ring fixture is a cylinder with a hole on the bottom surface The structure has a top fixedly connected to the load platform, a bottom maintaining a certain gap with the bottom of the fixed magnetic ring fixing part, and a gap is provided with the coil skeleton and the coil in the radial direction; the dynamic magnetic ring array is coaxially nested and tightly fitted and fixedly installed on the inner side of the dynamic magnetic ring fixing part, the bottom is fixedly connected to the upper surface of the bottom of the dynamic magnetic ring fixing part, the top is pressed and fixed by the dynamic magnetic ring positioning part, and a gap is provided with the coil skeleton and the coil in the radial direction; the coil skeleton is an annular sleeve with deep grooves arranged along the circumference of the outer cylindrical surface, the bottom of which is fixed, and a certain gap is maintained with the top of the load platform; the coil is coaxially nested and tightly fitted and fixedly installed in the annular deep groove on the outer side of the coil skeleton; the fixed magnetic ring array and the dynamic magnetic ring array are both arranged in an axial array in multiple layers , it is composed of equal-section magnetic rings with vertical magnetization between adjacent layers, among which the heights of the magnetic rings of odd-numbered layers are all equal, and the heights of the magnetic rings of even-numbered layers are all equal; the first layer of the fixed magnetic ring array and the dynamic magnetic ring array are magnetized in radial opposite directions, 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 dynamic magnetic ring rotates 90° counterclockwise; the sensor is fixedly connected to the load platform, and its output signal is transmitted to the controller by the collector after passing through the signal conditioner. The controller processes the signal using a control algorithm of composite acceleration and velocity feedback, and then transmits the output control voltage to the driver. The driver converts the control voltage into a control current, and the drive coil generates a control force acting on the load platform.

[0011] Preferably, the stiffness and damping control device is arranged in an adjacent gap with the large air-floating isolator micro-vibrator or the stiffness and damping control device is coaxially nested and fixedly installed in the cylinder of the large air-floating isolator micro-vibrator.

[0012] Preferably, the number of layers of the fixed magnetic ring array and the dynamic magnetic ring array satisfies 2n+1, where n≥1, n∈N + .

[0013] Preferably, the heights of the magnetic rings in the same layer in the fixed magnetic ring array and the dynamic magnetic ring array are equal, and the heights of the coil, the fixed magnetic ring array, and the dynamic magnetic ring array are equal.

[0014] Preferably, the bottom of the first layer of magnetic rings in the fixed magnetic ring array overlaps with the bottom of the first layer of magnetic rings in the moving magnetic ring array.

[0015] Preferably, the large air-floating micro-vibrator is sealed by a steel ring, an O-ring, a diaphragm or a pressure self-sealing method.

[0016] Preferably, the pressure of the compressed gas is 0.1 MPa to 0.8 MPa.

[0017] Preferably, the cylinder is connected in series with a plurality of sealed additional gas tanks via throttle holes or air pipes.

[0018] 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°.

[0019] Preferably, the sensor is a combination of a velocity sensor and an acceleration sensor.

[0020] Preferably, the numbers of throttling holes between adjacent additional gas tanks are different and their positions do not overlap.

[0021] Preferably, the throttling hole is in the shape of a triangle, a circle, a five-pointed star or other polygonal shapes.

[0022] Preferably, the velocity sensor and acceleration sensor are magnetoelectric, piezoelectric or inertial sensors.

[0023] Preferably, the coil skeleton is made of conductive but non-magnetic materials such as carbon fiber composite materials or hard plastics.

[0024] Preferably, the coil skeleton is made of non-conductive and non-magnetic materials such as boron nitride ceramics, nano-diamonds, and fiberglass.

[0025] Preferably, the signal conditioner comprises an amplifier and a filter, the gain of the amplifier is adjustable, and the filter is a high-pass filter with an adjustable cut-off frequency.

[0026] Preferably, the fixed magnetic ring fixing part, the moving magnetic ring fixing part, the fixed magnetic ring positioning part and the moving magnetic ring positioning part are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy materials.

[0027] The technical innovation and good effects of the present invention are:

[0028] (1) The present invention innovatively proposes a large-scale precision micro-vibration isolation stiffness and damping control device based on a vertical magnetization magnetic ring array. By innovating the stiffness and damping control configuration formed by the parallel magnetization magnetic array in the two-dimensional plane, a three-dimensional vertical magnetization magnetic ring array is used to construct a unilateral high magnetic density excitation magnetic field, and through advanced control algorithms and sensor feedback, adjustable high negative stiffness and eddy current damping characteristics are achieved, which greatly improves the magnetic field utilization and energy conversion efficiency, and provides a configuration basis for the stiffness and damping control of large-scale precision micro-vibration isolation of hundreds of tons and above. This is one of the innovative points that distinguish the present invention from the prior art.

[0029] (2) The present invention realizes the integrated regulation of the stiffness and damping parameters of large-scale precision micro-vibration isolation. By generating adjustable high negative stiffness and low-frequency high damping and high-frequency low damping characteristics, the stiffness and damping of large-scale precision micro-vibration isolation platforms of 100 tons and above are integrated and regulated, which can match the stiffness and damping parameters of the near full-band vibration isolation range and the full-frequency high-performance vibration isolation, thereby expanding the vibration isolation bandwidth, improving the vibration isolation performance, and achieving near full-band high-performance vibration isolation effects. This integrated regulation design effectively avoids the problem of single parameter regulation falling into a performance bottleneck, and gives large-scale precision vibration isolation systems stronger environmental adaptability and dynamic adjustment capabilities, enabling them to better adapt to complex challenges such as changes in load mass, fluctuations in excitation frequency, and diverse vibration isolation needs. This is the second innovation that distinguishes the present invention from the prior art.

[0030] (3) The present invention can improve the vibration isolation performance and stability of large-scale precision micro-vibration isolation systems. In some cases, vibration isolation systems based on single parameter control of stiffness or damping will not only fall into performance bottlenecks but also have stability problems. For example, adjusting only one parameter often cannot simultaneously meet multiple vibration isolation index requirements such as vibration isolation frequency band and vibration attenuation rate. Improper setting of stiffness and damping parameters or excessive external excitation may cause system instability. Integrated control can maximize vibration isolation performance and improve the stability of the vibration isolation system by matching stiffness and damping to achieve high-performance vibration isolation over the entire frequency band. This helps to reduce the phenomenon of vibration amplification caused by mismatch of stiffness and damping parameters or external interference. This is the third innovation that distinguishes the present invention from the prior art.

[0031] (4) The present invention has the advantages of compact structure, easy installation, and low maintenance cost. The core advantage of the stiffness and damping control device is that it can simultaneously produce adjustable high negative stiffness and low-frequency high damping and high-frequency low damping characteristics, avoiding the complex combination of independent negative stiffness structure and damping structure in the existing method. Through the integrated design, not only the volume and weight of the system are significantly reduced, making the overall structure more compact and saving installation space; in addition, due to the reduction of connecting parts between different components, while reducing the complexity of the system, it effectively reduces potential failure points and maintenance difficulties, the installation and maintenance costs are low, and the reliability and stability are improved. This is the fourth innovation that distinguishes the present invention from the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a three-dimensional view of the stiffness and damping control device;

[0033] Figure 2 is a front cross-sectional view of the stiffness and damping control device;

[0034] Figure 3 A three-dimensional diagram of Example 1 of the integrated control device for negative stiffness damping for large-scale precision micro-vibration isolation;

[0035] Figure 4 It is a front cross-sectional view of embodiment 1 of the negative stiffness damping integrated control device for large-scale precision micro-vibration isolation;

[0036] Figure 5 A three-dimensional diagram of Example 2 of the integrated control device for negative stiffness damping for large-scale precision micro-vibration isolation;

[0037] Figure 6 It is a front cross-sectional view of embodiment 2 of the negative stiffness damping integrated control device for large-scale precision micro-vibration isolation;

[0038] Figure 7 It is a front cross-sectional view of a large air-floating micro-vibrator when the air cylinder is connected in series with multiple additional air tanks through air pipes;

[0039] Figure 8 A front cross-sectional view of a large air-floating isolator micro-vibrator when the cylinder is connected in series with multiple additional air tanks through throttle holes.

[0040] Explanation of the part numbers in the figure: 1 ground, 2 fixed magnetic ring array, 3 fixed magnetic ring fixing part, 4 dynamic magnetic ring array, 5 dynamic magnetic ring fixing part, 6 coil, 7 coil frame, 8 load platform, 9 sensor, 10 signal conditioner, 11 collector, 12 controller, 13 driver, 14 stiffness and damping control device, 15 large air floating micro-vibrator, 16 upper cover, 17 elastic membrane, 18 cylinder, 19 compressed gas, 20 throttle hole, 21 additional gas tank, 22 fixed magnetic ring positioning part, 23 dynamic magnetic ring positioning part, 24 air pipe. DETAILED DESCRIPTION

[0041] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0042] The negative stiffness and damping integrated control device for large-scale precision micro-vibration isolation can accurately match the stiffness and damping parameters of large-scale precision micro-vibration isolation of 100 tons and above to achieve near full-band high-performance vibration isolation by generating adjustable high negative stiffness and low-frequency high damping and high-frequency low damping characteristics, so as to maximize the vibration isolation bandwidth and vibration isolation effect; it includes a load platform 8, a stiffness and damping control device 14 and a large-scale air-floating micro-vibration isolation device 15; the large-scale air-floating micro-vibration isolation device 15 includes an upper cover plate 16, an elastic membrane 17, a cylinder 18 and compressed gas 19, the upper cover plate 16 is fixedly connected to the load platform 8, and forms a closed air chamber with the elastic membrane 17 and the cylinder 18, and compressed gas 19 is introduced into the closed air chamber; the stiffness and damping control device 14 includes a fixed magnetic ring array 2, a fixed magnetic ring fixing part 3, a dynamic magnetic ring array 4, a dynamic magnetic ring fixing part 5, a dynamic magnetic ring fixing part 6, a dynamic magnetic ring fixing part 7, a dynamic magnetic ring fixing part 8, a dynamic magnetic ring fixing part 9, a dynamic magnetic ring fixing part 10, a dynamic magnetic ring fixing part 11, a dynamic magnetic ring fixing part 12, a dynamic magnetic ring fixing part 13, a dynamic magnetic ring fixing part 14, a dynamic magnetic ring fixing part 15, a dynamic magnetic ring fixing part 16 ...6, a dynamic magnetic ring fixing part 13, a dynamic magnetic ring fixing part 14, a dynamic magnetic ring fixing part 14, a dynamic magnetic ring fixing The magnetic ring fixing part 5, the coil 6, the coil skeleton 7, the sensor 9, the signal conditioner 10, the collector 11, the controller 12 and the driver 13, the fixed magnetic ring fixing part 3, the fixed magnetic ring array 2, the moving magnetic ring array 4, the moving magnetic ring fixing part 5, the coil skeleton 7 and the coil 6 are coaxially nested, and are arranged in sequence from the axis along the radius outward; the fixed magnetic ring fixing part 3 is a cylindrical structure with an inverted T-shaped cross-section, the bottom of which is fixed, and a gap is maintained between the top end and the load platform 8, and a gap is provided with the moving magnetic ring array 4 and the moving magnetic ring fixing part 5 in the radial direction; the fixed magnetic ring array 2 is coaxially nested and fixedly installed on the outer side surface of the fixed magnetic ring fixing part 3 in a tight fit, and the top end is pressed and fixed by the fixed magnetic ring positioning part 22, and a gap is provided with the moving magnetic ring array 4 and the moving magnetic ring fixing part 5 in the radial direction; the moving magnetic ring fixing part 5 is The cylindrical structure with a hole on the bottom surface has its top fixedly connected to the load platform 8, and its bottom maintains a certain gap with the bottom of the fixed magnetic ring fixing part 3, and has a gap with the coil skeleton 7 and the coil 6 in the radial direction; the dynamic magnetic ring array 4 is coaxially nested and tightly fitted on the inner side of the dynamic magnetic ring fixing part 5, and its bottom is fixedly connected to the upper surface of the bottom of the dynamic magnetic ring fixing part 5, and the top is pressed and fixed by the dynamic magnetic ring positioning part 23, and has a gap with the coil skeleton 7 and the coil 6 in the radial direction; the coil skeleton 7 is an annular sleeve with deep grooves arranged along the circumference of the outer cylindrical surface, and its bottom is fixed, and a certain gap is maintained between the top and the load platform 8; the coil 6 is coaxially nested and tightly fitted in the annular deep groove on the outer side of the coil skeleton 7; the fixed magnetic ring array 2 and the dynamic magnetic ring array 4 are both composed of multiple layers arranged along the axial direction. The structure is composed of equal-section magnetic rings arranged in rows and magnetized perpendicularly between adjacent layers, wherein the heights of the odd-numbered magnetic rings are all equal, and the heights of the even-numbered magnetic rings are all equal; the first layers of the fixed magnetic ring array 2 and the dynamic magnetic ring array 4 are magnetized in opposite directions along 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 sensor 9 is fixedly connected to the load platform 8, and its output signal is transmitted to the controller 12 by the collector 11 after passing through the signal conditioner 10. The controller 12 processes the signal using a control algorithm of composite acceleration and velocity feedback, and then transmits the output control voltage to the driver 13. The driver 13 converts the control voltage into a control current, and the drive coil 6 generates a control force acting on the load platform 8.

[0043] As a specific implementation, the stiffness damping control device 14 is arranged in an adjacent gap to the large air-floating isolation micro-vibrator 15 or the stiffness damping control device 14 is coaxially nested and fixedly installed in the cylinder 18 of the large air-floating isolation micro-vibrator 15 .

[0044] As a specific implementation method, the number of layers of the fixed magnetic ring array 2 and the moving magnetic ring array 4 satisfies 2n+1, where n≥1, n∈N + .

[0045] 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, and the heights of the coil 6 and the fixed magnetic ring array 2 and the moving magnetic ring array 4 are equal.

[0046] As a specific implementation manner, the bottom of the first layer of magnetic rings in the fixed magnetic ring array 2 coincides with the bottom of the first layer of magnetic rings in the moving magnetic ring array 4 .

[0047] As a specific implementation, the large air-floating micro-vibrator 15 adopts a steel ring seal, an O-type seal, a diaphragm seal or a pressure self-sealing method.

[0048] As a specific implementation, the pressure of the compressed gas 19 is 0.1 MPa to 0.8 MPa.

[0049] As a specific implementation, the cylinder 18 is connected in series with a plurality of sealed additional gas tanks 21 via a throttle hole 20 or an air pipe 24 .

[0050] 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°.

[0051] As a specific implementation, the sensor 9 is a combination of a velocity sensor and an acceleration sensor.

[0052] As a specific implementation, the number of throttle holes 20 between adjacent additional gas tanks 21 is different and the positions do not overlap.

[0053] As a specific implementation, the throttle hole 20 is in the shape of a triangle, a circle, a five-pointed star or other polygonal shapes.

[0054] As a specific implementation, the velocity sensor and the acceleration sensor are magnetoelectric, piezoelectric or inertial sensors.

[0055] As a specific implementation, the coil skeleton 7 is made of conductive but non-magnetic materials such as carbon fiber composite materials or hard plastics.

[0056] As a specific implementation, the coil skeleton 7 is made of non-conductive and non-magnetic materials such as boron nitride ceramics, nano-diamonds, and fiberglass.

[0057] As a specific implementation, the signal conditioner 10 includes an amplifier and a filter. The gain of the amplifier is adjustable, and the filter is a high-pass filter with an adjustable cutoff frequency.

[0058] As a specific implementation, the fixed magnetic ring fixing part 3, the moving magnetic ring fixing part 5, the fixed magnetic ring positioning part 22 and the moving magnetic ring positioning part 23 are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy materials.

[0059] Combine the following Figure 1 to Figure 4 An embodiment of the present invention is given.

[0060] The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation is composed of a load platform 8, a stiffness damping control device 14 and a large-scale air-floating micro-vibration isolation device 15. The stiffness damping control device 14 and the large-scale air-floating micro-vibration isolation device 15 are arranged in adjacent gaps and support the load platform 8 in parallel. The large-scale air-floating micro-vibration isolation device 15 stably supports the load platform 8 of 100 tons or more in a passive air-floating manner, and effectively isolates the medium and high frequency vibrations it is subjected to. The stiffness and damping control device 14 utilizes active magnetic levitation to generate adjustable high negative stiffness and low-frequency high damping and high-frequency low damping characteristics, and supports the load platform 8 in parallel with the large-scale air-floating micro-vibration isolation device 15. Without affecting the load-bearing mass, the stiffness and damping of large-scale precision micro-vibration isolation platforms of 100 tons and above can be integratedly controlled, thereby matching the stiffness and low-frequency high damping and high-frequency low damping parameters for achieving near-full-band high-performance vibration isolation, generating local near-zero stiffness and near-zero transmission rate characteristics, reducing the natural frequency of vibration isolation, expanding the vibration isolation bandwidth, and improving the vibration attenuation rate, thereby maximizing the vibration isolation performance and improving the stability of the vibration isolation system, providing an "ultra-quiet" working environment for cutting-edge instruments and equipment such as ultra-precision lithography machines, high-resolution satellite cameras, and ultra-precision machine tools.

[0061] As the core equipment of ultra-precision air-floating micro-vibration isolation technology, the large air-floating micro-vibration isolation device 15 is a non-metallic spring that fills compressed gas 19 in an elastic membrane 17 and uses the compressibility of the gas to achieve elastic support. Structurally, the large air-floating micro-vibration isolation device 15 is composed of an upper cover plate 16, an elastic membrane 17, a cylinder 18 and compressed gas 19. The upper cover plate 16 is fixedly connected to the load platform 8, and forms a closed air chamber with the elastic membrane 17 and the cylinder 18 through a steel ring seal, an O-ring seal, a diaphragm seal or a pressure self-sealing method. A compressed gas 19 of 0.1MPa to 0.8MPa is passed into the closed air chamber. When external micro-vibration interference acts on the large air-floating micro-vibration isolation device 15, the compressed gas 19 in the closed air chamber will be compressed and expanded accordingly according to the frequency and amplitude of the micro-vibration, thereby effectively absorbing and dissipating the vibration energy and achieving the vibration isolation effect. At the same time, by adjusting the pressure of the compressed gas 19 in the closed air chamber, stable support for different load masses and high-performance vibration isolation effects in the medium and high frequency bands can be achieved.

[0062] The stiffness damping control device 14 includes a fixed magnetic ring array 2, a fixed magnetic ring fixture 3, a moving magnetic ring array 4, a moving magnetic ring fixture 5, a coil 6, a coil skeleton 7, a sensor 9, a signal conditioner 10, a collector 11, a controller 12 and a driver 13. The fixed magnetic ring fixture 3, the fixed magnetic ring array 2, the moving magnetic ring array 4, the moving magnetic ring fixture 5, the coil skeleton 7 and the coil 6 are coaxially nested and arranged in sequence from the axis along the radius outward. The fixed magnetic ring fixture 3 is a cylindrical structure with an inverted T-shaped cross-section, the bottom of which is fixed, and the top of the fixed magnetic ring is kept at a gap of 30mm to 100mm with the load platform 8, which is greater than the sum of the floating height of the large air-floating micro-vibrator 15 and the maximum vibration amplitude of the load platform 8. The fixed magnetic ring fixture 3 is provided with a gap with the moving magnetic ring array 4 and the moving magnetic ring fixture 5 in the radial direction. The fixed magnetic ring array 2 is coaxially nested and fixedly mounted on the outer side of the fixed magnetic ring fixture 3 in a tight fit, and its top end is pressed and fixed by the fixed magnetic ring positioning piece 22, and a gap is provided with the moving magnetic ring array 4 and the moving magnetic ring fixture 5 in the radial direction. The moving magnetic ring fixture 5 is a cylindrical structure with a hole on the bottom surface, and its top end is fixedly connected to the load platform 8, and the bottom and the bottom of the fixed magnetic ring fixture 3 maintain a gap of 30mm to 100mm, and a gap is provided with the coil skeleton 7 and the coil 6 in the radial direction; the moving magnetic ring array 4 is coaxially nested and fixedly mounted on the inner side of the moving magnetic ring fixture 5 in a tight fit, and its bottom end is fixedly connected to the upper surface of the bottom of the moving magnetic ring fixture 5, and the top end is pressed and fixed by the moving magnetic ring positioning piece 23, and a gap is provided with the coil skeleton 7 and the coil 6 in the radial direction. Among them, the fixed magnetic ring fixing part 3, the moving magnetic ring fixing part 5, the fixed magnetic ring positioning part 22 and the moving magnetic ring positioning part 23 are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy materials, and the coil frame 7 is made of conductive and non-magnetic materials such as carbon fiber composite materials or hard plastics, or non-conductive and non-magnetic materials such as boron nitride ceramics, nano-diamonds, and fiberglass.

[0063] The fixed magnetic ring array 2 and the dynamic magnetic ring array 4 are both composed of multiple layers of magnetic rings with equal cross-sections arranged in an axial array and perpendicular magnetization between adjacent layers. The magnetic rings are all N44H brand Ru-Fe-B permanent magnets with a remanence of 13.54 kGs, an intrinsic coercive force of 12.66 kOe, and a relative magnetic permeability μ r =1.23. The inner radius and outer radius of the fixed magnetic ring array 2 are 13mm and 64mm respectively, the height of the odd-numbered fixed magnetic rings is 20mm, and the height of the even-numbered fixed magnetic rings is 34mm. The inner radius and outer radius of the moving magnetic ring array 4 are 70mm and 100mm respectively, the height of the odd-numbered moving magnetic rings is 20mm, and the height of the even-numbered moving magnetic rings is 34mm. The first layer of fixed magnetic rings is magnetized along the radius toward the axis, and the first layer of moving magnetic rings is magnetized from the axis along the radius outward. On the right half of the front section view, with each additional layer of magnetic rings, the magnetization direction of the fixed magnetic ring rotates 90° clockwise, and the magnetization direction of the moving magnetic ring rotates 90° counterclockwise. The radially magnetized magnetic rings in the fixed magnetic ring array 2 and the moving magnetic ring array 4 are both made of 8 42° tile-shaped magnets spliced ​​together, and the gap between adjacent tile-shaped magnets is 3°.

[0064] The coil frame 7 is an annular sleeve with deep grooves arranged along the circumference of the outer cylindrical surface. The bottom is fixed, and the top is kept at a gap of 30mm to 100mm with the load platform 8; the coil 6 is coaxially nested and tightly fixed in the annular deep groove on the outer side of the coil frame 7. The coil 6 is wound by a copper wire in a circle, and the diameter of the copper wire is not less than 0.25mm and not more than 2mm. Insulation treatment is performed between each layer or each section of the copper wire using insulating paint, insulating paper or insulating sleeve and other materials to prevent short circuit. The height of the coil 6 is equal to that of the fixed magnetic ring array 2 and the moving magnetic ring array 4, and the current is not more than 10A. The heat dissipation efficiency can be improved by increasing the heat dissipation area of ​​the coil 6 surface (such as using a heat sink or increasing air circulation), and liquid cooling or phase change cooling and other efficient cooling methods can also be used to quickly and effectively dissipate the heat generated by the coil 6 when it is working to prevent the coil 6 from overheating. The sensor 9 is a combination of a magnetoelectric, piezoelectric or inertial velocity sensor and an acceleration sensor. It collects the vibration of the load platform 8 in real time. The vibration signal is processed by a signal conditioner 10 with integrated amplification and filtering functions, and then transmitted to the controller 12 by the collector 11. The amplification factor of the signal conditioner 10 is adjustable, and the filter realizes a high-pass filtering function, and its cut-off frequency is adjustable. The controller 12 has a built-in precision control algorithm for composite acceleration and velocity feedback, and generates a control voltage after analyzing and accurately calculating the received signal. The control voltage is output to the driver 13 through the analog output function of the collector 11, and the driver 13 converts the control voltage into a control current to act on the coil 6.

[0065] Since the number of layers of the fixed magnetic ring array 2 and the moving magnetic ring array 4 satisfies 2n+1 (n≥1, n∈N +), the overall structure is symmetrical about the n+1th layer of magnetic rings, and the magnetic force on the moving magnetic ring array 4 is zero, and it is in a state of equilibrium. Under the excitation of axial micro-disturbance, the moving magnetic ring array 4 and the fixed magnetic ring array 2 will move relative to each other. At this time, the axial equilibrium state of the moving magnetic ring array 4 is broken, while the radial direction is still balanced. The axial magnetic force of the fixed magnetic ring array 2 on the moving magnetic ring array 4 is in the same direction as the vibration, so that it continues to move away from the equilibrium position. Without external force, the balance cannot be restored, that is, its axial magnetic force presents a negative stiffness characteristic. When the moving 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 moving magnetic ring array 4 is 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. When the number of layers of the fixed magnetic ring array 2 and the dynamic magnetic ring array 4 is 3 and the current in the coil 6 is 0, the stiffness damping control device 14 with the four structural parameters mentioned above can reduce the stiffness of the 53.13-ton large air-floating micro-vibration isolation platform by 28.40%, increase the attenuation rate of random vibration of the ground 1 from 70.85% to 75.44%, reduce the peak value of the vibration transmission rate from 15.61dB to 3.94dB, and attenuate by 74.76%, thereby expanding the vibration isolation bandwidth and improving the vibration isolation performance. When the load mass or the excitation frequency changes, the controller 12 uses the precision control algorithm of the composite acceleration and velocity feedback to analyze and accurately calculate the vibration signal to generate a control voltage, and the driver 13 converts the control voltage into a control current of the control coil 6, thereby adjusting the excitation magnetic field, changing the negative stiffness and damping value of the stiffness damping control device 14, and matching the stiffness and damping parameters to achieve near full-band high-performance vibration isolation. Therefore, the stiffness and damping control device 14 does not affect the bearing mass of the large precision micro-vibration isolation platform, and only controls its vibration isolation bandwidth and vibration isolation effect by generating negative stiffness and damping characteristics, thereby achieving high-performance vibration isolation effect in the full frequency band.

[0066] Figure 5 and Figure 6They are respectively a three-dimensional diagram and a front cross-sectional view of Example 2 of the negative stiffness and damping integrated control device for large-scale precision micro-vibration isolation, wherein the stiffness and damping control device 14 is coaxially nested and fixedly installed in the cylinder 18 of the large air-floating micro-vibrator isolation 15, and supports the load platform 8 in parallel with the large air-floating micro-vibrator isolation 15. The fixed magnetic ring array 2, the dynamic magnetic ring array 4 and the coil 6 in the stiffness and damping control device 14 are coaxially nested and fixedly mounted on the fixed magnetic ring fixture 3, the dynamic magnetic ring fixture 5 and the coil skeleton 7 respectively; the bottom of the fixed magnetic ring fixture 3 and the coil skeleton 7 are fixedly connected to the upper surface of the lower base plate of the cylinder 18, and the top thereof maintains a gap of 30mm to 100mm with the bottom of the upper cover plate 16, which is greater than the sum of the floating height of the large air-floating micro-vibrator 15 and the maximum vibration amplitude of the load platform 8; the top of the dynamic magnetic ring fixture 5 is fixedly connected to the bottom of the upper cover plate 16, and the bottom thereof maintains a gap of 30mm to 100mm with the upper surface of the lower base plate of the cylinder 18.

[0067] Figure 7 and Figure 8 These are two specific embodiments of a large-scale air-floating micro-vibrator 15. In these two designs, the cylinder 18 of the large-scale air-floating micro-vibrator 15 is connected in series with m additional gas tanks 21 through an air pipe 24 or a throttle hole 20. The number of throttle holes 20 between adjacent additional gas tanks 21 is different and the positions do not overlap. The two structures are respectively suitable for occasions with larger horizontal or vertical installation spaces. Both the air pipe 24 and the throttle hole 20 play a role in limiting the gas flow rate, so that the large-scale precision micro-vibration isolation system can respond to external vibrations more stably. By adjusting the diameter or length of the air pipe 24, the number, size and shape of the throttle hole 20, the vibration isolation damping characteristics can be optimized to meet different vibration isolation requirements.

Claims

1. The negative stiffness and damping integrated control device for large-scale precision micro-vibration isolation can accurately match the stiffness and damping parameters of large-scale precision micro-vibration isolation of 100 tons and above to achieve high-performance vibration isolation in the near full frequency band, thereby maximizing the vibration isolation bandwidth and vibration isolation effect by generating adjustable high negative stiffness and low-frequency high damping and high-frequency low damping characteristics; it is characterized by The invention comprises a load platform (8), a stiffness and damping control device (14) and a large air-floating micro-vibrator (15); the large air-floating micro-vibrator (15) comprises an upper cover plate (16), an elastic membrane (17), a cylinder (18) and compressed gas (19); the upper cover plate (16) is fixedly connected to the load platform (8) and forms a closed air chamber with the elastic membrane (17) and the cylinder (18); the compressed gas (19) is introduced into the closed air chamber; the stiffness and damping control device (14) comprises a fixed magnetic ring array (2), a fixed magnetic ring fixing part (3), a moving magnetic ring array (4), a moving magnetic ring fixing part (5), a coil (6), a coil frame (7), a sensor (9), a signal conditioner ( 10), a collector (11), a controller (12) and a driver (13), a fixed magnetic ring fixture (3), a fixed magnetic ring array (2), a dynamic magnetic ring array (4), a dynamic magnetic ring fixture (5), a coil skeleton (7) and a coil (6) are coaxially nested and arranged in sequence from the axis along the radius outward; the fixed magnetic ring fixture (3) is a cylindrical structure with an inverted T-shaped cross-section, the bottom of which is fixed, the top of which maintains a gap with the load platform (8), and a gap is provided with the dynamic magnetic ring array (4) and the dynamic magnetic ring fixture (5) along the radial direction; the fixed magnetic ring array (2) is coaxially nested and fixedly mounted on the outer side of the fixed magnetic ring fixture (3) in a tightly fitting manner, and the top of which is pressed and fixed by a fixed magnetic ring positioning member (22) , a gap is provided with the moving magnetic ring array (4) and the moving magnetic ring fixing part (5) in the radial direction; the moving magnetic ring fixing part (5) is a cylindrical structure with a hole in the bottom surface, the top end of which is fixedly connected to the load platform (8), the bottom of which maintains a certain gap with the bottom of the fixed magnetic ring fixing part (3), and a gap is provided with the coil skeleton (7) and the coil (6) in the radial direction; the moving magnetic ring array (4) is coaxially nested and fixedly installed on the inner side surface of the moving magnetic ring fixing part (5) in a tightly fitting manner, the bottom of which is fixedly connected to the upper surface of the bottom of the moving magnetic ring fixing part (5), the top end is pressed and fixed by the moving magnetic ring positioning part (23), and a gap is provided with the coil skeleton (7) and the coil (6) in the radial direction; the coil skeleton (7) is an outer cylindrical surface along the circular An annular sleeve with deep grooves arranged around the periphery thereof is fixed at the bottom and a certain gap is maintained between the top and the load platform (8); the coil (6) is coaxially nested and fixedly mounted in the annular deep groove on the outer side of the coil frame (7) in a tightly fitting manner; the fixed magnetic ring array (2) and the dynamic magnetic ring array (4) are both composed of multiple layers of magnetic rings of equal cross-section arranged in an axial array and magnetized perpendicularly between adjacent layers, wherein the heights of the magnetic rings of odd-numbered layers are all equal and the heights of the magnetic rings of even-numbered layers are all equal; the first layers of the fixed magnetic ring array (2) and the dynamic 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 dynamic magnetic ring rotates 90° counterclockwise;The sensor (9) is fixedly connected to the load platform (8), and its output signal is transmitted to the controller (12) by the acquisition instrument (11) after passing through the signal conditioner (10). The controller (12) processes the signal using a control algorithm of composite acceleration and velocity feedback, and then outputs a control voltage to the driver (13). The driver (13) converts the control voltage into a control current, and the drive coil (6) generates a control force to act on the load platform (8).

2. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The stiffness damping control device (14) is arranged in an adjacent gap with the large air-floating isolation micro-vibrator (15), or the stiffness damping control device (14) is coaxially nested and fixedly installed in the cylinder (18) of the large air-floating isolation micro-vibrator (15).

3. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The number of layers of the fixed magnetic ring array (2) and the dynamic magnetic ring array (4) satisfies 2n+1, where n≥1, n∈N + .

4. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claims 1 and 3 is characterized in that: The heights of the magnetic rings in the same layer in the fixed magnetic ring array (2) and the moving magnetic ring array (4) are equal, and the heights of the coil (6) and the fixed magnetic ring array (2) and the moving magnetic ring array (4) are equal.

5. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claims 1, 3 and 4, characterized in that: The bottom of the first layer of magnetic rings in the fixed magnetic ring array (2) overlaps with the bottom of the first layer of magnetic rings in the moving magnetic ring array (4).

6. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The large air-floating micro-vibrator (15) adopts a steel ring seal, an O-type seal, a diaphragm seal or a pressure self-sealing method.

7. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized by: The pressure of the compressed gas (19) is 0.1 MPa to 0.8 MPa.

8. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The cylinder (18) is connected in series with a plurality of sealed additional gas tanks (21) via throttle holes (20) or gas pipes (24).

9. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claims 1, 3, 4 and 5, 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°.

10. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The sensor (9) is a combination of a velocity sensor and an acceleration sensor.

11. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claims 1 and 8, characterized in that: The numbers of the throttle holes (20) between the adjacent additional gas tanks (21) are different and their positions do not overlap.

12. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claims 1, 8 and 11, characterized in that: The throttle hole (20) is in the shape of a triangle, a circle, a five-pointed star or other polygons.

13. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claims 1 and 10, characterized in that: The velocity sensor and the acceleration sensor are magnetoelectric, piezoelectric or inertial sensors.

14. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The coil frame (7) is made of conductive but non-magnetic materials such as carbon fiber composite materials or hard plastics.

15. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The coil skeleton (7) is made of non-conductive and non-magnetic materials such as boron nitride ceramics, nano-diamonds, and glass fiber reinforced plastics.

16. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The signal conditioner (10) comprises an amplifier and a filter. The gain of the amplifier is adjustable, and the filter is a high-pass filter with an adjustable cut-off frequency.

17. The negative stiffness damping integrated control device for large-scale precision micro-vibration isolation according to claim 1 is characterized in that: The fixed magnetic ring fixing part (3), the moving magnetic ring fixing part (5), the fixed magnetic ring positioning part (22) and the moving magnetic ring positioning part (23) are made of non-magnetic or weakly magnetic aluminum alloy or titanium alloy materials.

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