Large-size large-mass sleeve combined type axial extension arm microgravity unloading structure

Abstract

The invention relates to a large-size large-mass sleeve combined type axial extension arm microgravity unloading structure, and belongs to the field of mechanical engineering and electronic engineering. The concrete structure comprises four supporting platforms, a bottom interface platform, an extension arm main body, five groups of extension arm connecting pieces, a suspension rope, an unloading balance piece, an unfolding supporting frame, a suspension connecting disc, a pulley assembly and a guide limiting piece, the device is formed by serially connecting and penetrating metal cylinder structures with different diameters step by step from small to small; the motor drives the hoisting mechanism to rotate to drive the power rope to complete stretching of the stretching arm. The rope-driven sleeves can be synchronously unfolded through a series rope system. The invention mainly relates to a vertical self-adaptive multi-stage unloading method, unloading point position design, unloading device design, unloading parameter description and other technologies, through the technical method, high-precision microgravity unloading of the large-size and large-mass stretching arm can be achieved, and the unfolding performance of the stretching arm is debugged to the optimal state; and the optimal unfolding precision of the stretching arm is ensured.

Description

Technical Field

[0001] The invention belongs to the fields of mechanical engineering and electronic engineering, and relates to a large-size and large-mass sleeve combined axial extension arm microgravity unloading structure. Background Art

[0002] The large-size and large-mass extension arm in space is an important supporting device for large spacecraft payloads such as rocket connection parts, solar panels, high-precision antennas, and camera systems. The reliability of its deployment directly determines the success or failure of large spacecraft space missions. The large-size and large-mass extension arm is a universal supporting component that can be used for large spacecraft payloads. This high-performance extension arm can be applied to subsequent large-scale communication payloads, deep space exploration such as lunar bases, and other space missions, and has good application prospects and economic benefits. The main functions of the large-size and large-mass extension arm are to support large payload structures; increase the distance between the payload structure and the satellite body to reduce mutual interference. The extension arm is easy to transport and store, can save mass and volume, and has the advantage of being tightened to withstand a larger load during launch.

[0003] The large-size and large-mass extension arm is a multi-stage sleeve-type series structure, and its main features are large load-bearing capacity, long distance and large height. The existing technical problems are that the multi-stage extension arm unloading is uneven during the vertical large-height deployment process, the sleeve is easy to deflect, the accuracy is difficult to control, and the microgravity unloading is difficult. It cannot meet the test requirements of large loads for precise deployment of large-size extension arms. Therefore, it is necessary to accurately describe the microgravity unloading method of the multi-stage large-size sleeve extension structure. Summary of the invention

[0004] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to propose a large-size and large-mass sleeve-assembled axial extension arm microgravity unloading structure, to verify the spatial deployment accuracy and performance of the extension arm in advance, to ensure reliable deployment in orbit, and to provide safe support for space payloads.

[0005] The solution of the present invention is:

[0006] A large-size, large-mass sleeve-assembled axial extension arm microgravity unloading structure, comprising 4 support platforms, a bottom interface platform, an extension arm body, 5 sets of extension arm connectors, a suspension rope, an unloading balance, an expansion support frame, a suspension connection plate, a pulley assembly and a guide limiter;

[0007] Among them, 4 supporting platforms are distributed on the horizontal bottom surface in all directions; the bottom interface platform is arranged on the ground and is in the middle of the 4 supporting platforms; a connecting interface is provided at the upper end of the bottom interface platform, and the extension arm body is fixed to the bottom interface platform by a thread; 5 groups of extension arm connectors are arranged at intervals on the outside of the extension arm body in the vertical direction; each group of extension arm connectors includes 3 extension arm connectors, which are evenly distributed on the outer side wall of the extension arm body at the corresponding height along the circumferential direction; the number of suspension ropes matches that of the extension arm connectors, one end of the suspension rope is connected to the extension arm connector, and the other end of the suspension rope is connected to the extension arm connector. One end is connected to the pulley assembly and connected to the unloading balance piece; the unloading balance piece fixes the suspension rope through the connecting hole; the unfolding support frame includes 4 vertical beams, 2 horizontal orthogonal beams, and an inclined reinforcement beam; the bottom end of the unfolding support frame is connected to the supporting platform; the suspension connecting plate is a circular structure, the upper end of the suspension connecting plate is fastened to the lower side of the unfolding support frame by screws, and the lower end of the suspension connecting plate is provided with a threaded hole to fix the pulley assembly; the guide limit piece is connected to the unfolding support frame; the unloading balance piece moves inside the guide limit piece, and the movement direction of the unloading balance piece is limited by the guide limit piece.

[0008] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, the extension arm body includes sleeve I, sleeve II, sleeve III, sleeve IV, sleeve V and sleeve connecting flange; each sleeve outer wall is correspondingly installed with a group of extension arm connecting parts;

[0009] Among them, sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V are coaxially connected in series from bottom to top, and their diameters decrease successively; the sleeve connecting flange is sleeved on the outer wall of the bottom end of sleeve I; the sleeve connecting flange is docked with the bottom interface platform; and the axial expansion and contraction of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V are realized.

[0010] In the above-mentioned large-size, large-mass sleeve combined axial extension arm microgravity unloading structure, the bottom interface platform includes a main load-bearing rod, a hollow structure, an observation window and a sleeve mounting table; the lower end of the main load-bearing rod is in contact with the ground, and the upper end of the main load-bearing rod plays a supporting and connecting role for the sleeve mounting table; the hollow structure is a connecting channel inside and outside the bottom interface platform, allowing operators to enter and exit from it; the observation window facilitates the detection and confirmation of the situation inside the extension arm body; and the sleeve connecting flange is fixed on the sleeve mounting table.

[0011] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, the extension arm connecting part includes a main connecting part, a mounting hole, a curved surface structure, and a rope-threading hollow structure; the main connecting part is installed on the outer side of the extension arm body through the mounting hole; the curved surface structure matches the shape of the outer side surface of the extension arm body; the rope-threading hollow structure is connected and tightened with the suspension rope to realize the upward suspension and unloading of the extension arm connecting part by the suspension rope.

[0012] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, the unfolding support frame includes 4 main load-bearing trusses, 4 lower oblique cables, upper oblique cables, a cross-type structure and an upper load-bearing truss; wherein, the 4 main load-bearing trusses are fastened one by one to the upper end plane of the support platform; each lower oblique cable is used to connect the upper end of the corresponding main load-bearing truss and the outer side of the corresponding support platform, and the main load-bearing truss, the lower oblique cables and the support platform are combined to form a triangular stable structure to effectively support the pulley assembly; the cross-type structure is installed on the top of the 4 main load-bearing trusses to achieve connection to the top ends of the 4 main load-bearing trusses; the upper load-bearing truss is vertically installed at the center top of the cross-type structure; the upper oblique cables, the cross-type structure and the upper load-bearing truss form a stable triangular structure to ensure that the intermediate suspension connection plate is stably installed and has strong anti-deformation ability.

[0013] In the above-mentioned large-size and large-mass sleeve-combined axial extension arm microgravity unloading structure, the pulley assembly includes an air bearing, an angular displacement sensor, an oblique support beam, a vertical support beam, and a middle hollow structure; wherein the air bearing is fixed to the oblique support beam by a pin shaft; angular displacement sensors are arranged on both sides of the air bearing to perform real-time detection of the rotation angle of the air bearing; the oblique support beam and the vertical support beam are an integrated metal structure, which bears the gravity load of the extension arm connector and the unloading balance member; the suspension rope passes through the middle hollow structure and through the outer cylindrical surface of the air bearing for support, and the friction force is used to realize the synchronous linkage of the suspension rope and the air bearing.

[0014] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, the guide limiter includes an end connecting piece, a mounting hole, an intermediate transparent structure, and a guide slope; wherein the guide limiter is fixed to the main load-bearing truss through the mounting hole; the intermediate transparent structure is connected to the end connecting piece through a threaded hole; the intermediate transparent structure is used to observe the sliding operation state of the unloading balance piece on the inner side; the guide slope is a chamfered structure at the upper end of the intermediate transparent structure, which is convenient for the unloading balance piece to automatically align and smoothly enter the channel inside the intermediate transparent structure.

[0015] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, the overall height of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V after extension is 20m, and the aspect ratio is greater than 10; the weight of a single metal sleeve of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V is 100kg; the end of the extension arm body is loaded with a large-mass and overweight new energy payload.

[0016] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, an angular displacement sensor is arranged on the outside of the air bearing shaft system of the pulley assembly to monitor the traction rotation angle of the suspension rope during the deployment process under different sleeves and different unloading angles; at the same time, the angle difference is compared and calculated and analyzed through an algorithm, and feedback is given when the difference is greater than >0.5°, and the operation is stopped.

[0017] In the above-mentioned large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, the calculation method of the angle difference of the angular displacement sensor at different suspension points on the same sleeve structure is:

[0018] Set the angles on the left and right sides to be α and β respectively; the absolute value of the difference between α and β is |α-β;

[0019] When |α-β≤0.5°, it operates normally; when |α-β>0.5°, it stops operating.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] (1) Based on the characteristics of large-size and large-mass extension arms, the present invention innovatively designs a process method that can adapt to the high-precision assembly and microgravity unloading of multi-stage series-type large-size and large-mass sleeve structures, optimizes the microgravity test method, and reasonably screens and matches the unloading position and unloading layout according to the spatial relationship of the multi-stage sleeves;

[0022] (2) During the large-scale and large-mass extension arm deployment test of the present invention, a digital measurement process method is added to monitor and check multiple parameters such as deployment displacement during the deployment process in real time to ensure the reliability of the microgravity deployment test process;

[0023] (3) Aiming at the quantification and refinement of the test requirements for the large-size and large-mass extension arm test process, the present invention designs a multi-point balanced unloading method, which can achieve balanced unloading of the sleeve structure; adopts an open interface design method to accurately simulate the spacecraft interface, solving the problems of inconvenient operation in a small space and ergonomic design;

[0024] (4) The sleeve-type extension arm of the present invention has a large axial dimension, and the spatial dimensions of the sleeve, unloading balance member, rope, etc. are large. The unfolding length is long and the running trajectory is complex. During the unfolding process, there is easy to be yaw, tilt, and imbalance, which causes the sleeve to become unstable during the unfolding process and affects the unfolding accuracy and performance. By setting a guide limiter to guide and limit the movement trajectory of the unloading balance member and the rope, only the vertical extension movement is performed, which effectively reduces the disturbance caused by suspension error, motion friction, eccentricity error, etc., and improves the stability of the sleeve movement, providing a reference for the subsequent unfolding of large-size and large-mass sleeve-type mechanisms, and can meet the subsequent application needs of various models and markets. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the microgravity unloading structure of the extension arm of the present invention;

[0026] Figure 2 It is a schematic diagram of the main body of the extension arm of the present invention;

[0027] Figure 3 This is a top detail view of the microgravity unloading structure of the extending arm of the present invention;

[0028] Figure 4 This is a schematic diagram of the bottom interface platform of the present invention;

[0029] Figure 5 It is a schematic diagram of the extension arm connecting member of the present invention;

[0030] Figure 6 This is a schematic diagram of the support frame of the present invention;

[0031] Figure 7 It is a schematic diagram of the pulley assembly of the present invention;

[0032] Figure 8 It is a schematic diagram of the guide and limiting member of the present invention. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the embodiments.

[0034] The present invention provides a large-size, large-mass sleeve combined axial extension arm microgravity unloading structure. The large-size, large-mass extension arm is a rope-driven extension arm, which is mainly composed of metal cylinder structures of different diameters, which are connected in series step by step from small to large. The main components include a hoisting mechanism, a rope pulley device, a locking mechanism, and a sleeve mechanism. The hoisting mechanism is driven by a motor to rotate, driving the power rope to complete the extension of the extension arm. The rope-driven sleeve can be synchronously unfolded through a series of ropes. The present invention mainly involves a vertical adaptive multi-stage unloading method, unloading point design, unloading device design, unloading parameter description and other technologies. The above technical methods can realize high-precision microgravity unloading for large-size, large-mass extension arms, debug the extension arm deployment performance to the optimal state, and ensure that the deployment accuracy of the extension arm reaches the optimal state.

[0035] Large-size and large-mass sleeve combined axial extension arm microgravity unloading structure, such as Figure 1 As shown, it specifically includes 4 support platforms 1, a bottom interface platform 2, an extension arm body 3, 5 groups of extension arm connecting parts 4, a suspension rope 5, an unloading balance part 6, an unfolding support frame 7, a suspension connecting plate 8, a pulley assembly 9 and a guide limiter 10.

[0036] Among them, four supporting platforms 1 are distributed on the horizontal bottom surface in all directions; the bottom interface platform 2 is arranged on the ground and is in the middle position of the four supporting platforms 1; a connecting interface is provided at the upper end of the bottom interface platform 2, and the extension arm body 3 is fixed to the bottom interface platform 2 by a thread; five groups of extension arm connectors 4 are arranged at intervals on the outside of the extension arm body 3 in the vertical direction; each group of extension arm connectors 4 includes three extension arm connectors 4, which are evenly distributed on the outer side wall of the extension arm body 3 at a corresponding height along the circumferential direction; the number of suspension ropes 5 matches that of the extension arm connectors 4, one end of the suspension rope 5 is connected to the extension arm connector 4, and the other end of the suspension rope 5 is connected to the extension arm connector 4 Connect the pulley assembly 9 and connect it to the unloading balance member 6; the unloading balance member 6 fixes the suspension rope 5 through the connecting hole; the unfolding support frame 7 includes 4 vertical beams, 2 horizontal orthogonal beams, and an inclined reinforcement beam; the bottom end of the unfolding support frame 7 is connected to the supporting platform 1; the suspension connecting plate 8 is a circular structure, and the upper end of the suspension connecting plate 8 is fastened to the lower side of the unfolding support frame 7 by screws, and the lower end of the suspension connecting plate 8 is provided with a threaded hole to fix the pulley assembly 9; the guide limit member 10 is connected to the unfolding support frame 7; the unloading balance member 6 moves inside the guide limit member 10, and the movement direction of the unloading balance member 6 is limited by the guide limit member 10, such as Figure 3 shown.

[0037] like Figure 2 As shown, the extension arm body 3 includes sleeve I, sleeve II, sleeve III, sleeve IV, sleeve V and sleeve connecting flange; a set of extension arm connecting parts 4 are installed on the outer wall of each sleeve. Among them, sleeve I, sleeve II, sleeve III, sleeve IV, sleeve V are coaxially connected in series from bottom to top, and the diameters decrease in sequence; the sleeve connecting flange is sleeved on the outer wall of the bottom end of sleeve I; the sleeve connecting flange is docked with the bottom interface platform 2; and the axial extension and contraction of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V are realized.

[0038] like Figure 4 As shown, the bottom interface platform 2 includes a main load-bearing rod 2-1, a hollow structure 2-2, an observation window 2-3 and a sleeve mounting table 2-4; the lower end of the main load-bearing rod 2-1 is in contact with the ground, and the upper end of the main load-bearing rod 2-1 supports and connects the sleeve mounting table 2-4; the hollow structure 2-2 is a connecting channel inside and outside the bottom interface platform 2, allowing operators to enter and exit; the observation window 2-3 facilitates detection and confirmation of the situation inside the extension arm body 3; the sleeve connecting flange is fixed on the sleeve mounting table 2-4.

[0039] like Figure 5As shown, the extension arm connector 4 includes a main connector 4-1, a mounting hole 4-2, an arcuate surface structure 4-3, and a rope threading hollow structure 4-4; the main connector 4-1 is installed on the outer surface of the extension arm body 3 through the mounting hole 4-2; the arcuate surface structure 4-3 matches the shape of the outer surface of the extension arm body 3; the rope threading hollow structure 4-4 is connected and fastened to the suspension rope 5, so as to realize the upward hanging and unloading of the extension arm connector 4 by the suspension rope 5.

[0040] like Figure 6 As shown, the unfolded support frame 7 includes four main load-bearing trusses 7-1, four lower inclined slings 7-2, upper inclined slings 7-3, a cross structure 7-4 and an upper load-bearing truss 7-5; wherein the four main load-bearing trusses 7-1 are fastened one by one to the upper plane of the support platform 1; each lower inclined sling 7-2 is used to connect the upper end of the corresponding main load-bearing truss 7-1 and the outer side of the corresponding support platform 1, and the main load-bearing truss 7-1, the lower inclined sling 7-2 and the support platform 1 are combined to form a A triangular stable structure is formed to effectively support the pulley assembly 9; the cross structure 7-4 is installed on the top of the four main load-bearing trusses 7-1 to connect the tops of the four main load-bearing trusses 7-1; the upper load-bearing truss 7-5 is vertically installed at the center top of the cross structure 7-4; the upper inclined suspension cable 7-3, the cross structure 7-4, and the upper load-bearing truss 7-5 form a stable triangular structure to ensure that the middle suspension connection plate 8 is stably installed and has strong anti-deformation ability.

[0041] The gantry is a cross-type double gantry support structure, the lower bottom of the double gantry cross-type is a four-leg support, which has high stability and reliability, and the cross-connection area can meet the multi-point suspension requirements of the sleeve structure. The deployment support adopts a diagonal reinforcement structure to strengthen the truss structure, and diagonally supports the truss structure to improve the support stiffness of the truss structure, and the gravity unloading reliability is effectively improved.

[0042] like Figure 7 As shown, the pulley assembly 9 includes an air bearing 9-1, an angular displacement sensor 9-2, an oblique support beam 9-3, a vertical support beam 9-4, and an intermediate hollow structure 9-5; wherein the air bearing 9-1 is fixed to the oblique support beam 9-3 by a pin; angular displacement sensors 9-2 are arranged on both sides of the air bearing 9-1 to detect the rotation angle of the air bearing 9-1 in real time; the oblique support beam 9-3 and the vertical support beam 9-4 are an integrated metal structure, which bears the gravity load of the extension arm connector 4 and the unloading balance member 6; the suspension rope 5 passes through the intermediate hollow structure 9-5 and passes through the outer cylindrical surface of the air bearing 9-1 for support, and the friction force is used to realize the synchronous linkage of the suspension rope 5 and the air bearing 9-1.

[0043] like Figure 8As shown, the guide limit member 10 includes an end connection member 10-1, a mounting hole 10-2, an intermediate transparent structure 10-3, and a guide slope 10-4; wherein, the guide limit member 10 is fixed to the main load-bearing truss 7-1 through the mounting hole 10-2; the intermediate transparent structure 10-3 is connected to the end connection member 10-1 through a threaded hole; the intermediate transparent structure 10-3 is used to observe the sliding operation state of the unloading balance member 6 on the inner side; the guide slope 10-4 is a chamfered structure at the upper end of the intermediate transparent structure 10-3, which is convenient for the unloading balance member 6 to automatically align and smoothly enter the inner channel of the intermediate transparent structure 10-3.

[0044] In the present invention, the overall height of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V after extension is 20m, and the aspect ratio is greater than 10; the weight of a single metal sleeve of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V is 100kg; the end of the extension arm body 3 is loaded with a large-mass overweight new energy load.

[0045] An angular displacement sensor 9-2 is arranged on the outside of the air bearing 9-1 shaft system of the pulley assembly to monitor the traction rotation angle of the suspension rope 5 during the unfolding process under different sleeves and different unloading angles; at the same time, an algorithm is used to compare and calculate the angle difference, and when the difference is greater than >0.5°, feedback is given and the operation is stopped.

[0046] The calculation method of the angle difference of the angular displacement sensor 9-2 at different suspension points on the same sleeve structure is:

[0047] Set the angles on the left and right sides to α and β respectively; the absolute value of the difference between α and β is |α-β|;

[0048] When |α-β|≤0.5°, it operates normally; when |α-β|>0.5°, it stops operating.

[0049] The roughness of the inner surface of the unloading balance member 6 is set within Ra3.2, and the unloading balance member 6 moves downward along the guide limit member 10 with low friction and low disturbance under the action of gravity.

[0050] Preferably, multiple connection points are set on the sleeve II, sleeve III, sleeve IV, and sleeve V. In order to ensure the stability and balance of the suspension, the suspension adopts an equal-angle distribution, and a three-point balanced unloading method is adopted on the circumference. Three points are arranged on the circumference at intervals of 120°, and the force on the circumference of the sleeve structure is evenly distributed, so that the deployment process is smooth and reliable.

[0051] The bottom interface platform 2 is configured as a hollow structure with a size greater than 800-900 mm, taking into account the portability of operators entering the inner cavity of a large-diameter metal cylinder for operation, and can meet the ergonomic connection channel.

[0052] Preferably, the guide limiter 10 is composed of an end connector 10-1, a mounting hole 10-2, an intermediate transparent structure 10-3, a guide slope 10-4, etc. The end connector 10-1 is mainly used to realize the transfer of load from the truss, the mounting hole 10-2 is used to connect with the truss structure of the unfolding support frame 7, and the intermediate transparent structure 10-3 is made of highly transparent material, which is convenient for observing the slippage, eccentricity, bumping, etc. of the unloading balance member 6 on the inner side of the guide limiter 10, and timely obtaining the movement state of the unloading balance member 6. The guide slope is used to guide the unloading balance member 6 to prevent bumps and scratches, reduce the frictional movement resistance of the sleeve structure and the influence of the guide limiter 10 on the movement disturbance of the sleeve structure.

[0053] According to the characteristics of large-size and large-mass extension arms, the present invention innovatively designs a process method that can adapt to the high-precision assembly and microgravity unloading of multi-stage series-type large-size and large-mass sleeve structures, optimizes the microgravity test method, and reasonably screens and matches the unloading position and unloading layout according to the spatial relationship of the multi-stage sleeves.

[0054] The present invention adds a digital measurement process method during the large-size and large-mass extension arm deployment test, monitors and checks multiple parameters such as deployment displacement during the deployment process in real time, and ensures the reliability of the microgravity deployment test process.

[0055] Aiming at quantifying and refining the test requirements of the large-size and large-mass extension arm test process, the present invention designs a multi-point balanced unloading method, which can achieve balanced unloading of the sleeve structure. It adopts an open interface design method to accurately simulate the spacecraft interface, thus solving the problems of inconvenient operation in a small space and ergonomic design.

[0056] The telescopic extension arm of the present invention has a large axial dimension, and the spatial dimensions of the sleeve, unloading balance member, rope, etc. are large. The unfolding length is long and the running trajectory is complex. During the unfolding process, there is easy to be yaw, tilt, and imbalance, which causes the sleeve to become unstable during the unfolding process and affects the unfolding accuracy and performance. By setting a guide limiter, the unloading balance member and the rope movement trajectory are guided and restricted, and only the vertical extension movement is performed, which effectively reduces the disturbance caused by suspension error, motion friction, eccentricity error, etc., and improves the stability of the sleeve movement, providing a reference for the subsequent unfolding of large-size and large-mass telescopic mechanisms, and can meet the subsequent application needs of various models and markets.

[0057] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A large-size, large-mass sleeve-assembled axial extension arm microgravity unloading structure, characterized in that: It comprises four supporting platforms (1), a bottom interface platform (2), an extension arm body (3), five sets of extension arm connecting parts (4), a suspension rope (5), an unloading balance part (6), an unfolding support frame (7), a suspension connection plate (8), a pulley assembly (9) and a guide limiter (10); The four support platforms (1) are distributed on the horizontal bottom surface in a surrounding manner; the bottom interface platform (2) is arranged on the ground and is located in the middle of the four support platforms (1); a connection interface is provided at the upper end of the bottom interface platform (2), and the extension arm body (3) is fixed to the bottom interface platform (2) by means of a thread; five groups of extension arm connectors (4) are arranged at intervals on the outside of the extension arm body (3) in the vertical direction; each group of extension arm connectors (4) includes three extension arm connectors (4), which are evenly distributed on the outer side wall of the extension arm body (3) at a corresponding height in the circumferential direction; the number of suspension ropes (5) matches that of the extension arm connectors (4), one end of the suspension rope (5) is connected to the extension arm connector (4), and the other end of the suspension rope (5) is connected to the extension arm connector (4). The pulley assembly (9) is connected to the unloading balance member (6); the unloading balance member (6) fixes the suspension rope (5) through the connection hole; the unfolding support frame (7) includes 4 vertical beams, 2 horizontal orthogonal beams, and an inclined reinforcement beam; the bottom end of the unfolding support frame (7) is connected to the support platform (1); the suspension connection plate (8) is a circular structure, the upper end of the suspension connection plate (8) is fastened to the lower side of the unfolding support frame (7) by screws, and the lower end of the suspension connection plate (8) is provided with a threaded hole to fix the pulley assembly (9); the guide limit member (10) is connected to the unfolding support frame (7); the unloading balance member (6) moves inside the guide limit member (10), and the movement direction of the unloading balance member (6) is limited by the guide limit member (10).

2. According to claim 1, a large-size, large-mass sleeve combined axial extension arm microgravity unloading structure is characterized by: The extension arm body (3) comprises a sleeve I, a sleeve II, a sleeve III, a sleeve IV, a sleeve V and a sleeve connecting flange; a set of extension arm connecting parts (4) are correspondingly installed on the outer wall of each sleeve; Among them, sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V are coaxially connected in series from bottom to top, and their diameters decrease in sequence; the sleeve connecting flange is sleeved on the outer wall of the bottom end of sleeve I; the sleeve connecting flange is docked with the bottom interface platform (2); and the axial expansion and contraction of sleeve I, sleeve II, sleeve III, sleeve IV, and sleeve V are realized.

3. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 2 is characterized in that: The bottom interface platform (2) comprises a main load-bearing rod (2-1), a hollow structure (2-2), an observation window (2-3) and a sleeve installation table (2-4); the lower end of the main load-bearing rod (2-1) contacts the ground, and the upper end of the main load-bearing rod (2-1) supports and connects the sleeve installation table (2-4); the hollow structure (2-2) is a connecting channel inside and outside the bottom interface platform (2), allowing operators to enter and exit; the observation window (2-3) facilitates detection and confirmation of the inner side of the extension arm body (3); and a sleeve connection flange is fixed on the sleeve installation table (2-4).

4. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 3 is characterized in that: The extension arm connecting member (4) comprises a main connecting member (4-1), a mounting hole (4-2), an arcuate surface structure (4-3), and a rope threading hollow structure (4-4); the main connecting member (4-1) is mounted on the outer side surface of the extension arm main body (3) through the mounting hole (4-2); the arcuate surface structure (4-3) matches the shape of the outer side surface of the extension arm main body (3); the rope threading hollow structure (4-4) is connected and fastened to the suspension rope (5), so that the suspension rope (5) can hang and unload the extension arm connecting member (4) upward.

5. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 4 is characterized in that: The unfolded support frame (7) comprises four main load-bearing trusses (7-1), four lower inclined slings (7-2), an upper inclined sling (7-3), a cross structure (7-4) and an upper load-bearing truss (7-5); wherein the four main load-bearing trusses (7-1) are fastened one by one to the upper plane of the support platform (1); each lower inclined sling (7-2) is used to connect the upper end of the corresponding main load-bearing truss (7-1) and the outer side of the corresponding support platform (1), so as to form a three-piece structure of the main load-bearing truss (7-1), the lower inclined sling (7-2) and the support platform (1). After being combined, a triangular stable structure is formed, which effectively supports the pulley assembly (9); the cross-shaped structure (7-4) is installed on the top of the four main load-bearing trusses (7-1) to achieve the connection of the top ends of the four main load-bearing trusses (7-1); the upper load-bearing truss (7-5) is vertically installed on the center top of the cross-shaped structure (7-4); the upper inclined suspension cable (7-3), the cross-shaped structure (7-4), and the upper load-bearing truss (7-5) form a stable triangular structure, which ensures that the middle suspension connection plate (8) is stably installed and has strong anti-deformation ability.

6. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 5 is characterized in that: The pulley assembly (9) comprises an air bearing (9-1), an angular displacement sensor (9-2), an oblique support beam (9-3), a vertical support beam (9-4), and an intermediate hollow structure (9-5); wherein the air bearing (9-1) is fixed to the oblique support beam (9-3) by a pin shaft; angular displacement sensors (9-2) are arranged on both sides of the air bearing (9-1) to detect the rotation angle of the air bearing (9-1) in real time; the oblique support beam (9-3) and the vertical support beam (9-4) are an integrated metal structure to bear the gravity load of the extension arm connector (4) and the unloading balance member (6); the suspension rope (5) passes through the intermediate hollow structure (9-5) and passes through the outer cylindrical surface of the air bearing (9-1) for support, and the suspension rope (5) and the air bearing (9-1) are synchronously linked by friction.

7. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 6 is characterized by: The guide limiter (10) comprises an end connection piece (10-1), a mounting hole (10-2), an intermediate transparent structure (10-3), and a guide slope (10-4); wherein the guide limiter (10) is fixed to the main load-bearing truss (7-1) via the mounting hole (10-2); the intermediate transparent structure (10-3) is connected to the end connection piece (10-1) via a threaded hole; the intermediate transparent structure (10-3) is used to observe the sliding operation state of the unloading balance piece (6) on the inner side; and the guide slope (10-4) is a chamfered structure at the upper end of the intermediate transparent structure (10-3), which facilitates the unloading balance piece (6) to automatically align and smoothly enter the inner channel of the intermediate transparent structure (10-3).

8. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 7 is characterized in that: The overall height of the sleeve I, sleeve II, sleeve III, sleeve IV and sleeve V after extension is 20m, and the aspect ratio is greater than 10; the weight of a single metal sleeve of sleeve I, sleeve II, sleeve III, sleeve IV and sleeve V is 100kg; the end of the extension arm body (3) is loaded with a large-mass overweight new energy load.

9. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 7, characterized in that: An angular displacement sensor (9-2) is arranged outside the shaft system of the air bearing (9-1) of the pulley assembly to monitor the traction rotation angle of the suspension rope (5) during the unfolding process under different sleeves and different unloading angles; at the same time, an algorithm is used to perform a difference comparison calculation and analysis on the angle difference, and feedback is given when the difference is greater than >0.5°, and the operation is stopped.

10. The large-size, large-mass sleeve-assembled axially extending arm microgravity unloading structure according to claim 9, characterized in that: The calculation method of the angle difference of the angular displacement sensors (9-2) at different suspension points on the same sleeve structure is: Set the angles on the left and right sides to be α and β respectively; the absolute value of the difference between α and β is |α-β; When |α-β≤0.5°, it operates normally; when |α-β>0.5°, it stops operating.

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