CN117471562A - Vibration isolation system and relative gravity meter - Google Patents

Abstract

The application relates to a vibration isolation system and relative gravity appearance, this vibration isolation system includes: base, pendulum rod and magnetic levitation device. The magnetic levitation device comprises two first magnets and two second magnets. The vibration isolation system provided by the application enables the second magnets to be equal in stress places in the uniform magnetic field through the uniform magnetic field generated by each first magnet, so that approximately zero rigidity is realized. And the static magnetic force generated by each first magnet on the second magnet can balance the effective load of the second magnet and the swing rod, so that the problem that the larger the load is, the weaker the vibration isolation effect is, due to the contradiction between the load and the vibration isolation is solved.

Description

Vibration isolation system and relative gravity meter

Technical Field

The application relates to the technical field of measurement, in particular to a vibration isolation system and a relative gravity meter.

Background

Gravitational acceleration is an important physical quantity in celestial physics and celestial mechanics. It has important significance for understanding the provenance and evolution of universe, astrophysics, planetary science and other fields. In the process of measuring the gravitational acceleration, the gravitational acceleration of a measuring point is generally obtained by measuring the displacement and the time interval of the falling body relative to a reference prism in a free falling manner. During the measurement process, ground vibration can interfere with the reference prism, thereby affecting measurement accuracy.

In practice, vibration isolation devices of elastic structures of limited stiffness (such as springs) are often used to reduce the disturbance of ground vibrations to the reference prism when measuring gravitational acceleration.

However, vibration isolation using an elastic structure has a problem that there is a contradiction between load and vibration isolation.

Disclosure of Invention

In view of the above, it is desirable to provide a vibration isolation system and a relative gravimeter that can solve the contradiction between the load and the vibration isolation.

In a first aspect, the present application provides a vibration isolation system. The vibration isolation system includes: the device comprises a base, a swing rod and a magnetic levitation device;

the swing rod is connected with the base and is parallel to the base;

the magnetic levitation device comprises two first magnets and a second magnet, wherein one first magnet is arranged on one side of the swing rod close to the base, and the other first magnet is arranged on the other side of the swing rod far away from the base; the second magnets are arranged on the surface of the swing rod and are positioned between the two first magnets;

a uniform magnetic field is formed between the two first magnets, and the magnetic field force generated by each first magnet aiming at the second magnet is opposite to the gravity direction of the swing rod; the magnetic field force is used to balance a payload comprising the second magnet and the pendulum.

In one embodiment, the two first magnets have the same size, and the two first magnets have a size larger than that of the second magnet.

In one embodiment, the two first magnets have the same shape, and the two first magnets are any one of ring magnets, cylindrical magnets, and wedge magnets.

In one embodiment, the second magnet is a cylindrical magnet.

In one embodiment, the vibration isolation system further includes a first coil wound around a surface of the first magnet;

the first coil is used for generating a variable first magnetic field, and the first magnetic field is used for providing stress for the second magnet.

In one embodiment, the vibration isolation system further includes a second coil wound around a surface of the second magnet;

the second coil is used for generating a changed second magnetic field, and the second magnetic field is used for providing stress for the second magnet.

In one embodiment, the second coil is a helmholtz secondary coil.

In one embodiment, the vibration isolation system further comprises a displacement detection device and an adjusting device, wherein the displacement detection device is arranged between the swing rod and the base, the adjusting device is arranged between the swing rod and the base, and the displacement detection device is connected with the adjusting device;

the displacement detection device is used for detecting the displacement of the swing rod and transmitting the displacement to the adjustment device;

the adjusting device is used for applying compensation force to the swing rod according to displacement, and the compensation force is used for enabling the swing rod to move to the balance position.

In one embodiment, the vibration isolation adjustment device includes a voice coil motor.

In one embodiment, the vibration isolation system further includes a filter circuit, an input end of the filter circuit is connected with the displacement detection device, and an output end of the filter circuit is connected with the adjustment device.

In one embodiment, the vibration isolation system further includes a flexible connection member disposed between the swing link and the base for connecting the swing link and the base.

In one embodiment, the flexible connection unit includes a flexible hinge.

In a second aspect, the present application also provides a relative gravimeter. The relative gravimeter includes: a reference prism and the vibration isolation system of the first aspect described above; the reference prism is arranged on the swing rod in the vibration isolation system.

Above-mentioned vibration isolation system and relative gravity appearance, this vibration isolation system includes: the device comprises a base, a swing rod and a magnetic levitation device; the swing rod is connected with the base and is parallel to the base; the magnetic levitation device comprises two first magnets and a second magnet, wherein one first magnet is arranged on one side of the swing rod close to the base, and the other first magnet is arranged on the other side of the swing rod far away from the base; the second magnets are arranged on the surface of the swing rod and are positioned between the two first magnets; a uniform magnetic field is formed between the two first magnets, and the magnetic field force generated by each first magnet aiming at the second magnet is opposite to the gravity direction of the swing rod; the magnetic field force is used to balance a payload comprising the second magnet and the pendulum. According to the vibration isolation system, the second magnets are stressed everywhere in the uniform magnetic field through the uniform magnetic field generated by each first magnet, so that approximately zero rigidity is achieved. And the static magnetic force generated by each first magnet on the second magnet can balance the effective load of the second magnet and the swing rod, so that the contradiction between the load and the vibration isolation is solved, namely the problem that the larger the load is, the weaker the vibration isolation effect is.

Drawings

FIG. 1 is a schematic diagram of a prior art vibration isolation based on near zero stiffness of a permanent magnet;

FIG. 2 is a schematic diagram showing a second vibration isolation based on the near zero stiffness of the permanent magnet in the related art;

FIG. 3 is a schematic diagram of a related art ring permanent magnet based near zero stiffness system;

FIG. 4 is a schematic diagram of a vibration isolation system in one embodiment;

FIG. 5 is a schematic diagram of a vibration isolation system in another embodiment;

FIG. 6 is a schematic diagram of a relative gravimeter in one embodiment.

Reference numerals:

vibration isolation device: a vibration isolation system 1; a relative gravimeter 2; a base 11; a swing rod 12; a magnetic levitation device 13; a counterweight 14; a displacement detection module 15; an adjustment module 16; a flexible connection 17; a reference prism 18; a first magnet 131; a second magnet 132; a reflecting mirror 151; a beam splitter 151; a photodetector 153; a laser 154; voice coil motor 161.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

In the description of the present application, it should be understood that, if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., these terms refer to the orientation or positional relationship based on the drawings, which are merely for convenience of description and simplification of description, and do not indicate or imply that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

Furthermore, in the description of the present application, the terms "plurality" and "a plurality" mean at least two, such as two, three, etc., unless specifically defined otherwise.

In this application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly. For example, the two parts can be fixedly connected, detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this application, unless expressly stated or limited otherwise, the meaning of a first feature being "on" or "off" a second feature, and the like, is that the first and second features are either in direct contact or in indirect contact through an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that if an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. If an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein, if any, are for descriptive purposes only and do not represent a unique embodiment.

First, before a technical solution of an embodiment of the present application is specifically described, a description is first given of a technical background on which the embodiment of the present application is based.

During the process of measuring the gravitational acceleration, the ground vibration can interfere with the reference prism, thereby affecting the measurement accuracy. The ultra-low frequency vertical vibration isolation system can reduce the influence of ground vibration on the reference prism, and provides an inertial reference point for the system.

In the aspect of achieving vibration isolation based on approximately zero rigidity of a permanent magnet as shown in fig. 1, vibration isolation with six degrees of freedom is achieved by utilizing a pair of permanent magnets, and a magnetic field with uniform central gradient is constructed by adopting an upper annular magnet and a lower annular magnet, wherein a region with approximately zero gradient exists in the middle part of the central magnet under force as shown in fig. 2. The experimental and theoretical resonant frequencies of the system in the direction X, Y, Z are about 2.9Hz, 3Hz, 1.8Hz and 3Hz, 1.6Hz, respectively. However, this technique has a problem that the period is not long enough.

The approximate zero stiffness system based on the annular permanent magnet is shown in fig. 3, and the principle is that two magnetic rings magnetized in the axial direction are adopted to generate negative stiffness, and vibration isolation frequency finally obtained by the system is about 15 Hz. The vibration isolation frequency of the system is overlarge, and the elastic material is adopted for vibration isolation, so that the period of the vibration isolation system is shorter due to the design contradiction between the bearing capacity and the vibration isolation performance.

In addition, a linear electromagnetic spring and a linear spring are utilized to realize quasi-zero stiffness, the Linear Electromagnetic Spring (LES) is connected in parallel with a traditional linear isolation system, the LES can generate linear negative stiffness, positive stiffness of the traditional system is balanced, and natural frequency can be adjusted from 10Hz to the lowest 2Hz. The system utilizes elastic materials to perform vibration isolation, and the contradiction between rigidity and load exists.

As is clear from the above related art, in the conventional passive vibration isolation device, a limited stiffness elastic structure is often used, and it is necessary to solve the design contradiction between the bearing capacity and the vibration isolation performance by a complicated geometry structure or the like, and at the same time, there is a disadvantage in temperature characteristics.

Based on this, the application provides a vibration isolation system and relative gravimeter, aims at solving the technical problem.

In one embodiment, as shown in fig. 4, there is provided a vibration isolation system 1, the vibration isolation system 1 including: base 11, pendulum rod 12 and magnetic levitation device 13.

The swing rod 12 is connected with the base 11, alternatively, the swing rod 12 and the base 11 may be connected by a hinge, riveted, or connected by a bearing, and the connection mode of the swing rod 12 and the base 11 is not specifically limited in this embodiment of the present application. The swing rod 12 is transversely arranged and is parallel to the base 11 and the ground. Meanwhile, the swing rod 12 can be overlapped with a spring and the like to increase positive rigidity.

The magnetic levitation device 13 includes two first magnets 131 and two second magnets 132. The first magnet 131 and the second magnet 132 in the embodiment of the present application are permanent magnets. The first magnet 131 may include one of a ring magnet, a cylinder magnet, and a wedge magnet. The second magnet 132 may include a circular magnet, a cylindrical magnet.

One of the first magnets 131 is disposed on one side of the swing rod 12 close to the base 11, and the other first magnet 131 is disposed on the other side of the swing rod 12 far from the base 11. I.e. one first magnet 131 above the second magnet 132 and the other first magnet 131 below the second magnet 132. The first magnet 131 may be supported on the ground by a post. The number of columns is not particularly limited in this application. The second magnet 132 is disposed on the surface of the swing rod 12 and located between the two first magnets 131. The spacing can be adjusted by adding or reducing gaskets between the column and the upper and lower bases so as to achieve the effect of adjusting the stress interval and the rigidity of the instrument. In the magnetic field of the structure, particularly in a working range, the stress has good linearity.

The two first magnets 131 are used to form a uniform magnetic field, so that the second magnets 132 are forced to be equal everywhere in the uniform magnetic field. And the magnetic force generated by each first magnet 131 against the second magnet 132 is opposite to the gravity direction of the swing rod 12.

Optionally, the N-level of the first magnet 131 above the second magnet 132 faces upward S-level downward, and the N-level of the first magnet 131 below the second magnet 132 faces downward S-level upward, and the N-level of the middle second magnet 132 faces upward S-level downward, so that the first magnet 131 above and the second magnet 132 have the same polarization, and attractive force is generated to the second magnet 132. While the lower first magnet 131 has an opposite magnetization direction to the second magnet 132, generating a repulsive force to the second magnet 132, thereby achieving an upward force to the second magnet 132.

As can be seen from the formula of the magnetic dipole (the second magnet 132 in the embodiment of the present application) being stressed in the magnetic field, the magnetic dipole is stressed equally everywhere in the magnetic field with uniform gradient. In this magnetic field, a second magnet 132 is placed so that the magnetic field forces it receives in the magnetic field are balanced with itself and the pendulum 12 and the required devices, i.e. there is a everywhere equivalent restoring force of zero.

The vibration isolation system comprises a base, a swing rod and a magnetic levitation device. The swing rod is connected with the base, and the swing rod is parallel to the base. The magnetic levitation device comprises two first magnets and a second magnet, wherein one first magnet is arranged on one side of the swing rod close to the base, and the other first magnet is arranged on the other side of the swing rod far away from the base; the second magnet is arranged on the surface of the swing rod and is positioned between the two first magnets. A uniform magnetic field is formed between the two first magnets, and the magnetic field force generated by each first magnet aiming at the second magnet is opposite to the gravity direction of the swing rod. The magnetic field force is used to balance a payload comprising the second magnet and the pendulum. According to the vibration isolation system, the second magnets are stressed everywhere in the uniform magnetic field through the uniform magnetic field generated by each first magnet, so that approximately zero rigidity is achieved. And the static magnetic force generated by each first magnet on the second magnet can balance the effective load of the second magnet and the swing rod, so that the contradiction between the load and the vibration isolation is solved, namely the problem that the larger the load is, the weaker the vibration isolation effect is.

In another embodiment, the two first magnets 131 have the same size, and the two first magnets 131 have a larger size than the second magnets 132.

The present embodiment sets the first magnet 131 to a larger size and the second magnet 132 to a smaller size. The first magnet 131 generates a larger magnetic force to balance the gravity of the second magnet 132, the swing rod 12 and the counterweight 14. The specific dimensions of the first magnet 131 and the second magnet 132 are determined by the actual requirements.

According to the vibration isolation system, the two first magnets are identical in size, and the first magnets can generate magnetic fields with uniform gradients, so that the second magnets are equal everywhere, the vibration isolation period is effectively prolonged from the fact that approximately zero rigidity is realized. The two first magnets are set to be larger than the second magnet in size, so that the first magnets can generate magnetic field force to balance the gravity of the second magnet, the swing rod and the counterweight.

In one embodiment, the shapes of the two first magnets 131 are the same, and the two first magnets 131 are any one of ring magnets, cylindrical magnets, and wedge magnets.

In the embodiment of the present application, since the first magnet 131 is a permanent magnet, it is known in theory that the permanent magnet can generate a uniform magnetic field. By arranging the two first magnets 131 having the same shape, a magnetic field having a uniform gradient can be generated. The shape of the first magnet 131 may be any of a plurality of types, including a ring magnet, a cylindrical magnet, and a wedge magnet, and the specific shape of the first magnet 131 to be used is determined by actual needs.

In the vibration isolation system 1, the two first magnets 131 are arranged in the same shape, so that the first magnets 131 generate magnetic fields with uniform gradients, and the second magnets 132 are equal everywhere, thereby realizing approximately zero rigidity and effectively prolonging the vibration isolation period.

In another embodiment, the first magnet 131 may be of a variety of types with high applicability.

In one embodiment, the vibration isolation system 1 further includes a first coil wound around a surface of the first magnet 131.

In the embodiment of the application, the first coil includes, but is not limited to, a helm Huo Ci coil, a saddle-shaped coil, and the like, and a coil capable of generating a uniform magnetic field. The generated uniform magnetic field is the first magnetic field that can be varied. The first coil may be wound on the surface of the first magnet 131, or may be wound on any one of the two second magnets 132, which is not specifically limited in this embodiment.

The vibration isolation system 1 further comprises a first coil, the first coil can generate a first magnetic field with uniform intensity, the first coil is wound on the surface of the first magnet 131, the first magnetic field can provide stress for the second magnet 132, and the second magnet 132 can obtain a better stress curve.

In one embodiment, the vibration isolation system 1 further includes a second coil wound around a surface of the second magnet 132.

The second coil includes, but is not limited to, a helm Huo Ci coil, a saddle-shaped coil, and the like, which can generate a uniform magnetic field. The generated uniform magnetic field may generate a varying second magnetic field. The second coil may be wound on the first magnet 131. Alternatively, the second coil may be wound around both first magnets.

Above-mentioned vibration isolation system still includes the second coil, and the second coil can produce the even second magnetic field of intensity, twines the second coil on the surface of second magnet, and the second magnetic field can provide the atress for first magnet, can make the second magnet obtain better atress curve.

In another embodiment, the second coil is a helmholtz secondary coil.

Wherein the helmholy secondary coil is used to generate the magnetic field of the device in a nearly uniform region, a region of magnetic field strength closer to zero can be generated.

As shown in fig. 5, it can be seen that the second magnet 132 is stressed to vary by a small amount over a longer period, thus substantially satisfying the vibration isolation requirement. A helmholtz secondary coil may be added to the upper and lower first magnets 131 or the second magnets 132 to obtain a better stress curve or to compensate. If the helm Huo Ci coil is used to fine tune the magnetic field when the second magnet 132 is off-center, the stress at the off-center position can be closer to the stress at the center position, and the working interval can be enlarged, so that a better stress curve can be obtained. Meanwhile, the coil wound on the first magnet 131 may be energized, and the force of the second magnet 132 may be finely adjusted to compensate by generating a variable magnetic field by the current passing through the feedback control coil.

According to the vibration isolation system, the second coil is arranged as the Helmholtz secondary coil, so that the second magnet can obtain a better stress curve or compensate, and the vibration isolation capability of the vibration isolation system is further improved.

In another embodiment, as shown in fig. 6, the vibration isolation system 1 further includes a displacement detecting device 15 and an adjusting device 16.

In the embodiment of the present application, the displacement detecting device 15 is a photoelectric detecting circuit, and is disposed between the swing rod 12 and the base 11. The photodetection circuit includes a mirror 151, a beam splitter 152, a photodetector 153, and a laser 154. The reflector 151 is arranged below the swing rod 12, the spectroscope 152 and the four-quadrant photoelectric detector 153 are arranged right below the reflector 151, the four-quadrant photoelectric detector 153 is arranged on the base 11, and the spectroscope 152 is arranged on the four-quadrant photoelectric detector 153. The laser 154 is disposed on one side of the photodetector 153. The displacement detecting device 15 is used for detecting the displacement of the swing rod 12 and transmitting the displacement to the adjusting device 16. The adjusting device 16 is used for applying a compensation force to the swing rod 12 according to the displacement, and the compensation force is used for enabling the swing rod 12 to move to the balance position.

Optionally, the detector is a four-quadrant photodetector, which can accurately measure the motion state of the object.

Specifically, the laser 154 outputs the detection light, the detection light passes through the beam splitter 152 to the reflecting mirror 151, and then the detection light passes through the reflecting mirror 151 and then strikes the four-quadrant photodetector 153, so that if the swing rod 12 swings, the detection light on the four-quadrant photodetector 153 moves, and the swing displacement of the swing rod 12 can be calculated through the output of the four-quadrant photodetector 153. The photodetector 153 then transmits the displacement of the swing link 12 to the adjustment device 16. The adjustment device 16 applies a compensating force to the swing link 12 in accordance with the displacement to move the swing link 12 to the equilibrium position.

The vibration isolation system further comprises a displacement detection device and an adjusting device, and the displacement of the swing rod can be accurately calculated according to the four-quadrant photoelectric detector in the displacement detection device, so that the adjusting device can adjust the swing rod according to the displacement of the swing rod to compensate the drift of the vibration isolation system, and the vibration isolation capability of the vibration isolation system is further improved.

In another embodiment, with continued reference to fig. 6, the vibration isolation adjustment device 16 described above includes a voice coil motor 161.

The voice coil motor 161 is a special type of direct drive motor. Has the characteristics of simple structure, small volume, high speed, quick response and the like. The principle of operation is that an energized coil (conductor) will generate a force when placed in a magnetic field, wherein the magnitude of the force is proportional to the current applied to the coil.

In this embodiment, the vibration isolation adjusting device 16 adopts the voice coil motor 161, and can generate a corresponding force according to the displacement when receiving the displacement of the swing rod 12 output by the four-quadrant photodetector 153, and apply the corresponding force on the swing rod 12.

The vibration isolation system has the characteristics of simple structure, small volume, high speed, quick response and the like, and the vibration isolation adjusting device adopts the voice coil motor and can quickly adjust the displacement of the swing rod 12 through the displacement of the swing rod to generate corresponding force.

In another embodiment, the vibration isolation system 1 further includes a filter circuit, an input end of the filter circuit is connected to the displacement detecting device 15, and an output end of the filter circuit is connected to the adjusting device 16.

The filter circuit includes PI (Power Integrity) circuit, PI circuit and photoelectric detection circuit and voice coil motor 161.

In this embodiment, the PI circuit filters and amplifies the received displacement signal sent by the displacement detecting device 15, and then transmits the filtered and amplified displacement signal to the voice coil motor 161.

The vibration isolation system further comprises a filter circuit, and the filter circuit is arranged to filter and amplify the received displacement signals, so that the displacement signals received by the voice coil motor are more accurate.

In another embodiment, with continued reference to fig. 6, the vibration isolation system 1 further includes a flexible connection member 17, where the flexible connection member 17 is disposed between the swing link 12 and the base 11, and is used to connect the swing link 12 and the base 11.

Wherein, the flexible connecting piece 17 can be hinged connection, snap ring connection, spring connection, etc., and the flexible connecting piece 17 can connect the swing rod 12 and the base 11, so that the swing rod 12 can move in the vertical direction.

According to the vibration isolation system, the flexible connecting piece is arranged between the swing rod and the base, so that the swing rod can be limited to move in one dimension, and the system is limited to have one degree of freedom in the vertical direction, and errors caused by other degrees of freedom can be reduced.

In another embodiment, with continued reference to FIG. 6, the flexible connector 17 includes a flexible hinge.

The flexible hinge is an elastic support with simple structure and regular shape, has a rotation center coincident with a geometric center axis, and works by virtue of limited deformation of elastic sheets uniformly distributed in the circumferential radial direction. Under torsional loading, a rotational movement is produced about its center of rotation over a limited angular range.

The flexible connecting piece 17 of the embodiment of the application adopts a flexible hinge, and the swing rod 12 can be connected with the base 11 through the flexible hinge, so that the swing rod 12 can move in the vertical direction.

According to the vibration isolation system, the flexible connecting piece is connected with the base through the flexible hinge, so that mechanical friction between the swing rod and the base in the rotating process can be avoided, and system errors can be reduced in the balancing process.

In a second aspect, embodiments of the present application also provide a relative gravimeter 2. With continued reference to fig. 6, the relative gravity meter 2 includes: the reference prism 18 and the vibration isolation system 1 of the first aspect described above; as shown in fig. 6, the vibration isolation system 1 includes: a base 11, a swing rod 12 and a magnetic levitation device 13; the swing rod 12 is connected with the base 11, and the swing rod 12 is parallel to the base 11; the magnetic levitation device 13 comprises two first magnets 131 and a second magnet 132, wherein one first magnet 131 is arranged on one side of the swing rod 12 close to the base 11, and the other first magnet 131 is arranged on the other side of the swing rod 12 far from the base 11; the second magnet 132 is arranged on the surface of the swing rod 12 and is positioned between the two first magnets 131; a uniform magnetic field is formed between the two first magnets 131, and the magnetic field force generated by each first magnet 131 for the second magnet 132 is opposite to the gravity direction of the swing rod 12; the magnetic field force is used to balance the payload, which includes the second magnet 132 and the pendulum 12. A reference prism 18 is arranged on said pendulum 12 in the vibration isolation system 1.

The vibration isolation system of the embodiment of the application generates the uniform magnetic field through each first magnet, so that the second magnets are stressed everywhere in the uniform magnetic field to be equal, and zero-approximate rigidity is realized. And the static magnetic force generated by each first magnet on the second magnet can balance the effective load of the second magnet and the swing rod, so that the contradiction between the load and the vibration isolation is solved, namely the problem that the larger the load is, the weaker the vibration isolation effect is. Meanwhile, the vibration isolation system is used for isolating the reference prism, so that the influence on the stability of the reference prism can be reduced under the condition that the ground vibrates, and the measurement accuracy of the relative gravimeter is guaranteed.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.

Claims (13)

1. A vibration isolation system, the vibration isolation system comprising: the device comprises a base, a swing rod and a magnetic levitation device;

the swing rod is connected with the base, and the swing rod is parallel to the base;

the magnetic levitation device comprises two first magnets and two second magnets, one first magnet is arranged on one side of the swing rod, which is close to the base, and the other first magnet is arranged on the other side of the swing rod, which is far away from the base; the second magnets are arranged on the surface of the swing rod and are positioned between the two first magnets;

a uniform magnetic field is formed between the two first magnets, and the magnetic field force generated by each first magnet for the second magnet is opposite to the gravity direction of the swing rod; the magnetic field force is used to balance a payload comprising the second magnet and the pendulum rod.

2. The vibration isolation system of claim 1, wherein the two first magnets are the same size and the two first magnets are larger in size than the second magnets.

3. The vibration isolation system according to claim 1, wherein the two first magnets are identical in shape and are any one of a ring magnet, a cylindrical magnet, and a wedge magnet.

4. The vibration isolation system of claim 1, wherein the second magnet is a cylindrical magnet.

5. The vibration isolation system according to any one of claims 1 to 4, further comprising a first coil wound on a surface of the first magnet;

the first coil is used for generating a variable first magnetic field, and the first magnetic field is used for providing stress for the second magnet.

6. The vibration isolation system according to any one of claims 1 to 4, further comprising a second coil wound on a surface of the second magnet;

the second coil is used for generating a changed second magnetic field, and the second magnetic field is used for providing stress for the second magnet.

7. The vibration isolation system of claim 6, wherein the second coil is a helmholtz secondary coil.

8. The vibration isolation system according to any one of claims 1 to 4, further comprising a displacement detection device and an adjustment device, wherein the displacement detection device is disposed between the swing link and the base, the adjustment device is disposed between the swing link and the base, and the displacement detection device is connected to the adjustment device;

the displacement detection device is used for detecting the displacement of the swing rod and transmitting the displacement to the adjustment device;

the adjusting device is used for applying compensation force to the swing rod according to the displacement, and the compensation force is used for enabling the swing rod to move to the balance position.

9. The vibration isolation system of claim 8, wherein the adjustment device comprises a voice coil motor.

10. The vibration isolation system of claim 8, further comprising a filter circuit having an input coupled to the displacement detection device and an output coupled to the adjustment device.

11. The vibration isolation system according to any one of claims 1-4, further comprising a flexible connection member disposed between the pendulum bar and the base for connecting the pendulum bar and the base.

12. The vibration isolation system of claim 11, wherein the flexible connection comprises a flexible hinge.

13. A relative gravimeter, said relative gravimeter comprising: a reference prism and a vibration isolation system according to any one of claims 1-12;

the reference prism is arranged on the swing rod in the vibration isolation system.