Zero-gravity suspension compensation device and compensation method based on magnetic suspension

Abstract

The zero-gravity suspension compensation device based on magnetic suspension comprises an overall vertical frame and a truss, the overall vertical frame comprises a chassis, a plurality of stand columns are evenly distributed on the chassis, and one stand column serves as a main stand column and is connected with the tops of the other stand columns through suspension rails; a suspension concave frame capable of sliding along each suspension track is nested on each suspension track, a hanging spring is connected to the bottom of each suspension concave frame, the other end of each hanging spring is connected to a truss, and the truss is connected with the inner side of the main stand column. The invention further discloses a suspension compensation method, the permanent magnets on the bottom face interact to provide magnetic force for balancing gravity, and the permanent magnets on the side face interact to provide guiding force; when the suspension concave frame generates transverse displacement, non-contact and friction-free suspension is realized, and the resistance of the suspension concave frame in the linear motion direction along the suspension track is extremely small; when the suspension body rotates around the track under the action of torque, the guide wheels also rotate and make contact with the suspension track to offset the action of the torque, and gravity compensation is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of truss-type mesh deployable antenna devices, and in particular relates to a zero-gravity suspension compensation device based on magnetic levitation, and also relates to a zero-gravity suspension compensation method based on magnetic levitation. Background Art

[0002] Space deployable antennas are widely used in space missions such as satellite communications, earth observation, and deep space exploration, and have become a hot topic for research in various countries. Among various antenna designs, the annular truss mesh deployable antenna has become the first choice for space deployable antenna research due to its advantages of large storage ratio and low surface density.

[0003] The ring antenna is mainly composed of a front cable net, a metal reflective net, a vertical cable, a peripheral truss, a rear cable net, etc. The peripheral truss is composed of multiple truss units, and the truss unit structure is composed of rods, cables, joints, etc. The rods are divided into: steel frame rods, synchronization rods, and connecting rods. The joints are divided into: radial joints and circumferential joints. The hinged four-bar synchronization mechanism is used at the steel frame joint to ensure the synchronous deployment of adjacent steel frames. In addition, when the mechanism is fully deployed and the joint is locked, the four-bar mechanism will evolve into a triangular structure. The mechanism is deployed by winding the cable through the motor, tensioning the diagonal of the four-bar mechanism to continuously reduce the distance. The connecting rod is installed between two adjacent hinged four-bar units and constructs a parallelogram unit to ensure the synchronous deployment effect. In order to ensure the smooth deployment of the antenna in orbit, it is necessary to conduct a ground deployment test on it, so a device is needed to simulate the zero-gravity environment in space.

[0004] The traditional method is to simulate the microgravity environment by using the wire counterweight method. This method compensates for gravity by applying a vertical upward external force to the antenna suspension point. It mainly consists of two parts: a follow-up system and a suspension system: the suspension system consists of a counterweight and a fixed pulley to provide a constant suspension force for the wire; the follow-up system mainly consists of a pulley and a guide rail. The traction force of the antenna deployment causes the pulley to move with it, thereby achieving synchronous movement of the wire and the suspension point. Because the counterweight and the mass of the antenna both act on the pulley, although the sliding line is in contact, the friction generated is still very large, resulting in asynchronous movement of the pulley and the suspension point. And the wire is a flexible rope, and the wire will have a non-plumb effect during movement, which will cause insufficient unloading force. Summary of the invention

[0005] The purpose of the present invention is to provide a zero-gravity suspension compensation device based on magnetic levitation, so as to solve the problem that the traditional suspension method uses a fixed pulley and a counterweight to compensate for gravity, resulting in excessive friction resistance that affects the deployment of the truss.

[0006] The present invention also aims to provide a zero-gravity suspension compensation method based on magnetic levitation.

[0007] The first technical solution adopted by the present invention is: a zero-gravity suspension compensation device based on magnetic levitation, including an overall frame and a truss, the overall frame includes a chassis, and a plurality of columns are evenly distributed on the chassis, one of which is used as a main column and is connected to the tops of the remaining columns through a suspension track; each suspension track is nested with a suspension concave frame that can slide along the suspension track, the bottom of the suspension concave frame is connected with a hanging wire, the other end of the hanging wire is connected to the truss, and the truss is connected to the inner side of the main column.

[0008] The present invention is also characterized in that:

[0009] The truss is composed of multiple truss units, which are composed of rods, cables, and joints. The rods are divided into steel frame rods, synchronous rods, and connecting rods. The steel frame rods, synchronous rods, and connecting rods are connected by radial joints and circumferential joints. A hinged four-bar synchronization mechanism is adopted at the joints of the steel frame rods to ensure the synchronous expansion of adjacent steel frame rods. The steel frame rods are connected to the inner side of the main column through fixed supports and hexagon socket screws.

[0010] The uprights are inserted into the rectangular slots of the chassis to form an overall upright frame.

[0011] The suspension track comprises a U-shaped aluminum alloy groove, the bottom and side surfaces of the U-shaped aluminum alloy groove are both affixed with acrylic plates, and a permanent magnet array is affixed to the acrylic plate.

[0012] The suspended concave frame is adapted to the shape of the U-shaped aluminum alloy groove. A guide wheel is arranged close to the outer side surface of the suspended concave frame and the U-shaped aluminum alloy groove. A deep groove ball bearing is installed in the guide wheel. The deep groove ball bearing can bear radial load and axial load at the same time. The inner side surface of the U-shaped aluminum alloy groove is provided with a side suspension array in the length direction, and the inner side surface of the suspended concave frame is provided with a side suspension permanent magnet. The side suspension array repels the side suspension permanent magnet and the positions thereof correspond. The concave inner bottom surface of the suspended concave frame is provided with a bottom suspension permanent magnet. The inner bottom surface of the U-shaped aluminum alloy groove is provided with a bottom suspension array in the length direction. The bottom suspension array repels the bottom suspension permanent magnet and the positions thereof correspond.

[0013] A U-shaped pulley is arranged at the middle position of the lower bottom surface of the suspended concave frame close to the U-shaped aluminum alloy groove, the hanging wire is wound around the U-shaped pulley, and the other end of the hanging wire is connected to the annular joint of the truss.

[0014] The suspension rail is fixed to the top of the column with bolts through the hexagonal holes.

[0015] The second technical solution adopted by the present invention is a zero-gravity suspension compensation method based on magnetic levitation, which adopts a suspension concave frame provided with permanent magnets and a U-shaped aluminum alloy groove provided with a permanent magnet array. The bottom permanent magnets interact with each other to provide magnetic force to balance gravity, and the side permanent magnet array interacts with the side permanent magnets of the suspension concave frame to provide guiding force; when the suspension concave frame undergoes lateral displacement, the guide wheel contacts the U-shaped aluminum alloy groove and is in line contact, the contact friction is extremely small, the magnetic levitation is contactless and frictionless suspension, and the suspension concave frame has extremely small resistance in the straight line motion direction of the suspension track; when the suspension body rotates around the track under the action of torque, the guide wheel also rotates and contacts the suspension track to offset the torque to achieve gravity compensation.

[0016] The present invention is also characterized in that:

[0017] The specific steps are as follows:

[0018] Step 1: Install the column on the chassis, and then fix one end of the suspension track on the column; determine the mass of the truss to be m, and according to the truss structure design, the number of unloading tracks is n, and the unloading weight of each suspension track is

[0019] Step 2: Put the suspended concave frame on the suspended track, and then fix the other end of the suspended track; wrap a long enough hanging wire around the U-shaped pulley at the bottom of the suspended concave frame. At this time, there is no load, the suspended concave frame floats up, and the U-shaped pulley is close to the bottom of the suspended track;

[0020] Step 3: Connect one end of the hanging wire to the truss. At this time, the truss is in an unexpanded state. The suspended concave frame begins to slowly sink under the load until it reaches a stable state and is located at a balanced position in the center of the track. The permanent magnet array on the bottom and the permanent magnet array on the side of the suspension track are respectively facing the permanent magnet on the bottom and the permanent magnet on the side of the suspension body. At this time, the force in the Z direction is: F z The magnetic force in the Z direction is: F y1 =F y2 ;

[0021] Step 4: The motor starts to drive the cable to slowly unfold the truss, and the suspended concave frame moves along the length direction of the suspension track as the truss unfolds;

[0022] Due to the non-plumb effect of the hanging wire, the truss expansion process will generate a lateral disturbance force F y , the suspended concave frame produces a lateral displacement Δy1; at this time, the distance between the permanent magnet on one side of the suspension and the permanent magnet array on the side of the track decreases, while the distance on the other side increases, resulting in a magnetic force difference, F y1 ≠F y2 ; When |F y1 -F y2 |=F yIt reaches a stable state again and continues to move along the length of the suspension track until the suspension wire is in a plumb state. y disappears, generating a magnetic force difference that allows the suspended body to move to an equilibrium position;

[0023] If |F y1 -F y2 |≠F y , the suspended concave frame continues to move horizontally until the guide wheel contacts the side of the suspended track. At this time, the suspended concave frame moves along the length direction of the suspended track and is subject to contact friction resistance: F f =μ(F y1 -F y2 +F y ), μ is the friction coefficient;

[0024] When the suspended concave frame is subjected to the interference torque, it will produce angular displacement The center of gravity o undergoes a displacement of Δy. In this process, F y1 、F y2 、F y From the energy point of view, if the gravitational potential energy increases during the process, the original equilibrium position can be returned to; at this time, the torque is: The structure is in an unstable state, and the suspended concave frame begins to rotate. When the guide wheel rotates to contact the suspension track, the torque T is obtained.

[0025]

[0026] Wherein, L is the distance from the outer side of the side permanent magnet to the center of gravity o, and K is the distance from the bottom surface of the bottom permanent magnet to the center of gravity o;

[0027] At this time, the torque is balanced, the structure is in a stable state, and the suspended concave frame no longer moves.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The magnetic levitation antenna is suspended horizontally by magnetic force. The non-contact suspension makes the movement frictionless and eliminates the jamming phenomenon of the traditional solution. And as the load changes, the suspension height will be passively adjusted to solve the problem of insufficient vertical suspension force of the suspension wire caused by the non-plumb effect of the suspension wire.

[0030] (2) The present invention adopts a guide wheel structure, which has anti-interference capabilities against lateral disturbances and rotational torque, and solves the problem of lateral additional external force generated by the non-plumb effect of the hanging wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the overall structure of the zero-gravity suspension compensation device based on magnetic levitation of the present invention.

[0032] Figure 2It is a schematic diagram of the connection structure between the suspended concave frame and the U-shaped aluminum alloy groove of the present invention.

[0033] Figure 3 It is a schematic diagram of the suspended concave frame structure of the present invention.

[0034] Figure 4 It is a schematic diagram of the fixing structure of the column top and the suspension track of the present invention.

[0035] Figure 5 It is a schematic diagram of the overall force analysis of the suspended concave frame of the present invention.

[0036] Figure 6 It is a schematic diagram of the connection method between the truss and the column of the present invention.

[0037] Figure 7 It is a schematic diagram of the truss unit structure of the present invention.

[0038] In the figure, 1. chassis, 2. column, 3. suspension concave frame, 4. suspension track, 5. guide wheel, 6. side suspension array, 7. side suspension permanent magnet, 8. hexagonal head bolt, 9. U-shaped aluminum alloy groove, 10. hanging wire, 11. U-shaped pulley, 12. bottom suspension array, 13. bottom suspension permanent magnet, 14. deep groove ball bearing, 15. truss, 16. hexagonal head bolt for reamed hole, 17. fixed support, 18. hexagon socket screw. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the present invention more clear, the implementation modes of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0040] Example 1

[0041] The zero-gravity suspension compensation device based on magnetic suspension of the present invention is as follows: Figure 1 As shown, it includes an overall frame and a truss 15, the overall frame includes a chassis 1, and a plurality of columns 2 are evenly distributed on the chassis 1, one of which serves as a main column and is connected to the tops of the remaining columns through a suspension track 4; each suspension track 4 is embedded with a suspension concave frame 3 that can slide along the suspension track 4, the bottom of the suspension concave frame 3 is connected to a hanging wire 10, the other end of the hanging wire 10 is connected to the truss 15, and the truss 15 is connected to the inner side of the main column.

[0042] like Figure 6-7 As shown, the truss 15 is composed of multiple truss units, and the truss units are composed of rods, cables, and joints. The rods are divided into steel frame rods, synchronization rods, and connecting rods. The steel frame rods, synchronization rods, and connecting rods are connected by radial joints and circumferential joints; a hinged four-bar synchronization mechanism is adopted at the joints of the steel frame rods to ensure the synchronous expansion of adjacent steel frame rods. The steel frame rods are connected to the inner side of the main column through a fixed support 17 and a hexagon socket screw 18.

[0043] In addition, when the mechanism is fully deployed and the joints are locked, the four-bar mechanism will evolve into a triangular structure. The mechanism is deployed by winding the cable with the motor, which stretches the diagonal of the four-bar mechanism to reduce its distance. The connecting rod is installed between two adjacent articulated four-bar units and forms a parallelogram unit to ensure synchronous deployment.

[0044] like Figure 4 As shown, the suspension track 4 is fixed to the top of the column 2 by means of hexagonal head reamed hole bolts 16. The hexagonal head reamed hole bolts 16 can bear a large lateral load and tightly connect the suspension track to the column to prevent the suspension track from lateral displacement.

[0045] like Figure 2 As shown, the suspension track 4 includes a U-shaped aluminum alloy groove 9, the bottom and side surfaces of the U-shaped aluminum alloy groove 9 are both attached with acrylic plates, and a permanent magnet array is attached on the acrylic plate in the extension direction.

[0046] like Figure 3 As shown, the suspended concave frame 3 is adapted to the shape of the U-shaped aluminum alloy groove 9, and a guide wheel 5 is provided near the outer side of the suspended concave frame 3 and the U-shaped aluminum alloy groove 9. A deep groove ball bearing 14 is installed in the guide wheel 5, and the deep groove ball bearing 14 can bear radial load and axial load at the same time. The inner side of the U-shaped aluminum alloy groove 9 is provided with a side suspension array 6 in the length direction, and the inner side of the suspended concave frame 3 is provided with a side suspension permanent magnet 7. The side suspension array 6 repels the side suspension permanent magnet 7 and the positions thereof correspond; the concave inner bottom surface of the suspended concave frame 3 is provided with a bottom suspension permanent magnet 13, and the inner bottom surface of the U-shaped aluminum alloy groove 9 is provided with a bottom suspension array 12 in the length direction, and the bottom suspension array 12 repels the bottom suspension permanent magnet 13 and the positions thereof correspond;

[0047] A U-shaped pulley 11 is provided at the middle position of the lower bottom surface of the suspended concave frame 3 near the U-shaped aluminum alloy groove 9, and the hanging wire 10 is wound around the U-shaped pulley 11, and the other end of the hanging wire 10 is connected to the annular joint of the truss.

[0048] The permanent magnets of the present invention are installed in array form on the bottom and side surfaces of the U-shaped aluminum alloy groove. The bottom permanent magnet array interacts with the bottom permanent magnets on the suspended concave frame to provide a magnetic force that balances gravity. The side permanent magnet array interacts with the side permanent magnets on the suspended concave frame to provide a guiding force.

[0049] The guide wheel 5 is installed on the left and right sides of the suspended concave frame with hexagonal bolts, flat washers and hexagonal bolts 8, and the U-shaped pulley 11 is installed on the bottom surface of the suspended concave frame in the same way. A deep groove ball bearing 14 is installed in the guide wheel 5. The deep groove ball bearing 14 has a small friction coefficient and can bear radial loads and axial loads at the same time. The U-shaped pulley 11 is wound with a hanging wire 10, one end of which is connected to the truss annular joint, and the suspended concave frame 3 is sleeved on the suspension track 4, and the suspension track 4 is connected between two columns; the suspended truss begins to unfold under the drive of the motor, and the suspended concave frame passively moves in a straight line along the suspension track along the unfolding trajectory of the annular joint. When the truss unfolds and is disturbed by the lateral force and the suspended concave frame is laterally displaced, the guide wheel 5 contacts the U-shaped aluminum alloy groove 9 and is in line contact, and the contact friction is extremely small. Magnetic suspension is a contactless and frictionless suspension, and the resistance of the suspended concave frame 3 along the linear motion direction of the suspension track is extremely small. When the suspended concave frame 3 is subjected to the torque and rotates around the suspended track, the guide wheel 5 also rotates and contacts the track to offset the torque.

[0050] In the technical solution of the present invention, the column 2 is inserted into the rectangular groove of the chassis 1 to form an overall frame. Magnetic levitation gravity compensation is passive compensation, which reduces the levitation height as the load increases, provides greater levitation force, and does not require active control.

[0051] Example 2

[0052] Zero-gravity suspension compensation methods based on magnetic levitation, such as Figure 5 The specific steps are as follows:

[0053] Step 1: Install the column on the chassis, and then fix one end of the suspension track on the column; determine the mass of the truss to be m, and according to the truss structure design, the number of unloading tracks is n, and the unloading weight of each suspension track is

[0054] Step 2: Put the suspended concave frame on the suspended track, and then fix the other end of the suspended track; wrap a long enough hanging wire around the U-shaped pulley at the bottom of the suspended concave frame. At this time, there is no load, the suspended concave frame floats up, and the U-shaped pulley is close to the bottom of the suspended track;

[0055] Step 3: Connect one end of the hanging wire to the truss. At this time, the truss is in an unexpanded state. The suspended concave frame begins to slowly sink under the load until it reaches a stable state and is located at a balanced position in the center of the track. The permanent magnet array on the bottom and the permanent magnet array on the side of the suspension track are facing the permanent magnet on the bottom and the permanent magnet on the side of the user suspension body respectively. At this time, the force in the Z direction is: F z The magnetic force in the Z direction is: F y1 =F y2 ;

[0056] Step 4: The motor starts to drive the cable to slowly unfold the truss, and the suspended concave frame moves along the length direction of the suspension track as the truss unfolds;

[0057] Due to the non-plumb effect of the hanging wire, the truss expansion process will generate a lateral disturbance force F y , the suspended concave frame produces a lateral displacement Δy1; at this time, the distance between the permanent magnet on one side of the suspension and the permanent magnet array on the side of the suspension track decreases, while the distance on the other side increases, resulting in a magnetic force difference, F y1 ≠F y2 ; When |F y1 -F y2 |=F y It reaches a stable state again and continues to move along the length of the suspension track until the suspension wire is in a plumb state. y disappears, generating a magnetic force difference that allows the suspended body to move to an equilibrium position;

[0058] If |F y1 -F y2 |≠F y , the suspended concave frame continues to move laterally until the guide wheel contacts the side of the suspension track. At this time, the suspended concave frame moves along the length direction of the suspension track and is subject to contact friction resistance: F f =μ(F y1 -F y2 +F y ), μ is the friction coefficient;

[0059] When the suspended concave frame is subjected to the interference torque, it will produce angular displacement The center of gravity o of the suspended concave frame undergoes a displacement of Δy. In this process, F y1 、F y2 、F y From the energy point of view, if the gravitational potential energy increases during the process, the original equilibrium position can be returned to; at this time, the torque is: The structure is in an unstable state, and the suspended concave frame begins to rotate. When the guide wheel rotates to contact the suspension track, the torque T is obtained.

[0060]

[0061] Wherein, L is the distance from the outer side of the side permanent magnet to the center of gravity o, and K is the distance from the bottom surface of the bottom permanent magnet to the center of gravity o;

[0062] At this time, the torque is balanced, the structure is in a stable state, and the suspended concave frame no longer moves.

[0063] Example 3

[0064] When the mass of the truss 15 changes, the height of the suspended concave frame 3 also changes, resulting in a change in the facing area between the side suspended permanent magnet 7 of the suspended concave frame 3 and the side suspended array 6 on the inner side of the U-shaped aluminum alloy groove; when subjected to lateral disturbance at this time, the difference in repulsive force on the left and right sides is not enough to adjust the suspended concave frame 3 to the center position, and the suspended concave frame 3 will have surface contact with the suspended track 4, generating sliding friction during the truss deployment process, affecting the deployment effect; therefore, guide wheels are installed on the left and right sides of the suspended concave frame 3, changing the above-mentioned surface contact into line contact, and changing the sliding friction into rolling friction, thereby greatly reducing the contact friction.

[0065] The truss 15 is suspended on the suspended concave frame 3 by the hanging wire 10 to obtain gravity compensation, and the steel frame rod of the truss is connected to the column 2 by the fixed support 17; the truss is unfolded by the motor winding the cable, and the diagonal of the four-bar mechanism is tensioned to reduce the distance. As the truss is unfolded, the suspended concave frame also moves synchronously on the suspended track with the movement of the truss until the unfolding process is completed.

[0066] The permanent magnet array and the size of the permanent magnets are determined according to the mass of the truss and the weight that needs to be unloaded on each suspension track.

[0067] The above specific implementation methods of the present invention do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A zero-gravity suspension compensation device based on magnetic levitation, characterized in that: The invention comprises an overall frame and a truss (15), wherein the overall frame comprises a chassis (1), a plurality of columns (2) are evenly distributed on the chassis (1), one of which is used as a main column and is connected to the tops of the other columns via a suspension track (4); a suspension concave frame (3) capable of sliding along the suspension track (4) is embedded on each suspension track (4), a hanging wire (10) is connected to the bottom of the suspension concave frame (3), the other end of the hanging wire (10) is connected to the truss (15), and the truss (15) is connected to the inner side of the main column.

2. The zero-gravity suspension compensation device based on magnetic levitation according to claim 1, characterized in that: The truss (15) is composed of a plurality of truss units, each of which is composed of rods, cables, and joints. The rods are divided into steel frame rods, synchronous rods, and connecting rods. The steel frame rods, synchronous rods, and connecting rods are connected via radial joints and circumferential joints. A hinged four-bar synchronization mechanism is used at the joints of the steel frame rods to ensure the synchronous expansion of adjacent steel frame rods. The steel frame rods are connected to the inner side of the main column via a fixed support (17) and a hexagon socket screw (18).

3. The zero-gravity suspension compensation device based on magnetic levitation according to claim 1, characterized in that: The upright post (2) is inserted into the rectangular groove of the chassis (1) to form an overall upright frame.

4. The zero-gravity suspension compensation device based on magnetic levitation according to claim 2, characterized in that: The suspension track (4) comprises a U-shaped aluminum alloy groove (9), the bottom and side surfaces of the U-shaped aluminum alloy groove (9) are both affixed with acrylic plates, and a permanent magnet array is affixed to the acrylic plate.

5. The zero-gravity suspension compensation device based on magnetic levitation according to claim 4, characterized in that: The suspended concave frame (3) is adapted to the shape of the U-shaped aluminum alloy groove (9); a guide wheel (5) is arranged near the outer side surface of the suspended concave frame (3) and the U-shaped aluminum alloy groove (9); a deep groove ball bearing (14) is installed in the guide wheel (5); the deep groove ball bearing (14) can bear radial load and axial load at the same time; the inner side surface of the U-shaped aluminum alloy groove (9) is provided with a side suspension array (6) in the length direction; the inner side surface of the suspended concave frame (3) is provided with a side suspension permanent magnet (7); the side suspension array (6) and the side suspension permanent magnet (7) repel each other and their positions correspond; the concave inner bottom surface of the suspended concave frame (3) is provided with a bottom suspension permanent magnet (13); the inner bottom surface of the U-shaped aluminum alloy groove (9) is provided with a bottom suspension array (12) in the length direction; the bottom suspension array (12) and the bottom suspension permanent magnet (13) repel each other and their positions correspond; A U-shaped pulley (11) is provided at the middle position of the lower bottom surface of the suspended concave frame (3) close to the U-shaped aluminum alloy groove (9), the hanging wire (10) is wound around the U-shaped pulley (11), and the other end of the hanging wire (10) is connected to the annular joint of the truss.

6. The zero-gravity suspension compensation device based on magnetic levitation according to claim 1, characterized in that: The suspension track (4) is fixed to the top of the column (2) by bolts (16) through hexagonal holes.

7. A zero-gravity suspension compensation method based on magnetic levitation, characterized in that: A suspended concave frame with permanent magnets and a U-shaped aluminum alloy slot with a permanent magnet array are used. The bottom permanent magnets interact with each other to provide magnetic force to balance gravity, and the side permanent magnet array interacts with the side permanent magnets of the suspended concave frame to provide guiding force. When the suspended concave frame undergoes lateral displacement, the guide wheel contacts the U-shaped aluminum alloy groove and is in line contact. The contact friction is extremely small. The magnetic levitation is contactless and frictionless suspension. The resistance of the suspended concave frame along the linear motion direction of the suspension track is extremely small. When the suspended body rotates around the track under the action of torque, the guide wheel also rotates and contacts the suspension track to offset the torque and achieve gravity compensation.

8. The zero-gravity suspension compensation method based on magnetic levitation according to claim 7, characterized in that: The details are as follows: Step 1: Install the column on the chassis, and then fix one end of the suspension track on the column; determine the mass of the truss to be m, and according to the truss structure design, the number of unloading tracks is n, and the unloading weight of each suspension track is Step 2: Put the suspended concave frame on the suspended track, and then fix the other end of the suspended track; wind a sufficiently long hanging wire around the U-shaped pulley at the bottom of the suspended concave frame; at this time, there is no load, the suspended concave frame floats up, and the U-shaped pulley is close to the bottom of the suspended track; Step 3: Connect one end of the hanging wire to the truss. At this time, the truss is in an unexpanded state. The suspended concave frame begins to slowly sink under the load until it reaches a stable state and is located at a balanced position in the center of the track. The permanent magnet array on the bottom and the permanent magnet array on the side of the suspension track are respectively facing the permanent magnet on the bottom and the permanent magnet on the side of the suspension body. At this time, the force in the Z direction is: F z The magnetic force in the Z direction is: F y1 =F y2 ; Step 4: The motor starts to drive the cable to slowly unfold the truss, and the suspended concave frame moves along the length direction of the suspension track as the truss unfolds; Due to the non-plumb effect of the hanging wire, the truss expansion process will generate a lateral disturbance force F y , the suspended concave frame produces a lateral displacement Δy1; at this time, the distance between the permanent magnet on one side of the suspension and the permanent magnet array on the side of the track decreases, while the distance on the other side increases, resulting in a magnetic force difference, F y1 ≠F y2 ; When |F y1 -F y2 |=F y It reaches a stable state again and continues to move along the length of the suspension track until the suspension wire is in a plumb state. y disappears, generating a magnetic force difference that allows the suspended body to move to an equilibrium position; If |F y1 -F y2 |≠F y , the suspended concave frame continues to move horizontally until the guide wheel contacts the side of the suspended track. At this time, the suspended concave frame moves along the length direction of the suspended track and is subject to contact friction resistance: F f =μ(F y1 -F y2 +F y ), μ is the friction coefficient; When the suspended concave frame is subjected to the interference torque, it will produce angular displacement The center of gravity o undergoes a displacement of Δy. In this process, F y1 、F y2 、F y From the energy point of view, if the gravitational potential energy increases during the process, the original equilibrium position can be returned to; at this time, the torque is: The structure is in an unstable state, and the suspended concave frame begins to rotate. When the guide wheel rotates to contact the suspension track, the torque T is obtained. Wherein, L is the distance from the outer side of the side permanent magnet to the center of gravity o, and K is the distance from the bottom surface of the bottom permanent magnet to the center of gravity o; At this time, the torque is balanced, the structure is in a stable state, and the suspended concave frame no longer moves.

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