A top-shock-absorbing, space-coil extension arm using a gapless hinge

Abstract

This invention relates to the field of aerospace technology and provides a space-wound extendable arm with top vibration absorption and a gapless hinge, comprising: a top platform and a base; and a wound extendable arm installed between the top platform and the base. The top platform includes an accelerometer and an electromagnetic active vibration absorber, generating motion relative to the base to apply bending and torsional moments to compensate for the dynamic deformation of the wound extendable arm. The wound extendable arm includes a gapless hinge to eliminate hinge gaps. This invention can apply active vibration suppression and eliminate hinge gaps. Compared with existing space-wound extendable structures, it greatly improves the dynamic stability and overall stiffness of the extended arm after deployment, effectively improves the dynamic pointing accuracy of the load, is easy to implement, has high reliability of the mechanism and its components, can be adapted to a large number of control algorithms, can be combined with various hardware applications, has low manufacturing costs, high engineering feasibility, and good application prospects.

Description

Technical Field

[0001] This invention belongs to the field of aerospace technology, and in particular relates to a space-wound extendable arm with top vibration absorption and a gapless hinge. Background Technology

[0002] Space-wound extendable arms are one-dimensional flexible deployment structures with advantages such as high compressibility and large mass coefficient. They can be used as gravity gradient stabilization components for spacecraft attitude control, payload support platforms, etc. To meet the needs of satellite-borne instruments, such as high-precision optical detectors, high-precision magnetometers, or high-resolution remote sensing cameras in space missions, the movement and vibration of the extendable arm must be controlled within an extremely small range. This places higher demands on the stiffness and stability of space-wound extendable arms.

[0003] In existing spatial coiled extendable arm structures, the longitudinal and transverse connecting members of each layer need to rotate relative to each other to meet the movement requirements during folding and unfolding. Therefore, a hinge structure is used. However, the hinge design has a gap between the two parts forming the rotating pair. When the extendable arm is unfolded in space and subjected to external loads, the gap causes the hinge components to contact and wobble, affecting the overall stiffness of the extendable arm. Therefore, to enhance the stiffness and stability of the spatial coiled extendable arm, it is necessary to eliminate the gap in the hinge components.

[0004] Meanwhile, as a typical space flexible truss structure, the space spiral extension arm is prone to low-frequency, large-amplitude flexible vibrations under the excitation of the spacecraft body and external loads due to its large deflection and dense low-frequency modes. Such vibrations are difficult to attenuate in a short time and will have an adverse effect on the high-precision pointing load at the top. Summary of the Invention

[0005] The purpose of this invention is to provide a space-wound extension arm with top vibration absorption and a gapless hinge, in order to solve the problems existing in the background art.

[0006] This invention is implemented as follows: a spatially coiled extendable arm with top vibration absorption and a gapless hinge, comprising:

[0007] Top platform and base;

[0008] A coiled extension arm is installed between the top platform and the base;

[0009] The top platform includes an acceleration sensor and an electromagnetic active power vibration absorber, which generate motion relative to the base to apply bending and torsional moments to compensate for the dynamic deformation motion of the coiled extension arm.

[0010] The coiled extension arm includes a contactless gap hinge to eliminate hinge gaps.

[0011] Preferably, the coiled extension arm comprises:

[0012] A triangular crossbar, wherein the triangular crossbar has multiple layers, and each layer of the triangular crossbar consists of three crossbars and three non-contact gap hinges;

[0013] The longitudinal bar has three longitudinal bars, and the triangular crossbar is connected to the longitudinal bar by a non-contact gap hinge;

[0014] The cable connects to the triangular crossbeams of the adjacent layer.

[0015] Preferably, the contactless gap hinge comprises:

[0016] V-shaped connector, wherein the V-shaped connector has a cable connection hole, and the cable passes through the V-shaped connector for connection;

[0017] The longitudinal rod connector mates with the V-shaped connector and connects to the longitudinal rod;

[0018] The bearing is installed in the V-shaped connector and is axially fixed to the V-shaped connector. The fixing screw passes through the bearing and is threaded into the longitudinal rod connector. The longitudinal rod connector and the fixing screw form a whole and can rotate relative to the V-shaped connector.

[0019] Preferably, the top platform includes:

[0020] Top cover;

[0021] An electromagnetic active power vibration absorber, wherein three electromagnetic active power vibration absorbers are provided and are installed on the top cover in an equilateral triangular shape, consistent with the triangular crossbar;

[0022] An accelerometer is provided, and three accelerometers are mounted on the electromagnetic active power vibration absorber via a bracket. They are used to measure the vibration amplitude of the top platform in three directions.

[0023] The upper plate is mounted on the top cover, and the coiled extension arm is connected to the upper plate.

[0024] Preferably, the electromagnetic active vibration absorber includes:

[0025] shell;

[0026] A coil sleeve, which is axially mounted inside a housing, and a coil is installed in the coil sleeve;

[0027] A permanent magnet is mounted axially inside a housing. Both ends of the permanent magnet are connected to the housing via diaphragm springs. There is a gap between the permanent magnet and the inner wall of the coil.

[0028] The present invention provides a top-shoulder, gapless, spiral-shaped extension arm that can apply active vibration suppression and eliminate hinge gaps. Compared with existing spiral-shaped extension structures, it greatly improves the dynamic stability and overall stiffness of the extension arm after deployment, effectively improves the dynamic pointing accuracy of the load, is easy to implement, has high reliability of the mechanism and its components, can be adapted to a large number of control algorithms, can be combined with various hardware applications, has low manufacturing cost, high engineering feasibility, and has good application prospects. Attached Figure Description

[0029] Figure 1 A schematic diagram of a spatial spiral extension arm with top vibration absorption and gapless hinge provided in an embodiment of the present invention;

[0030] Figure 2 A partial view of a coiled extender arm in a space coiled extender arm that absorbs vibration at the top and uses a gapless hinge, provided as an embodiment of the present invention;

[0031] Figure 3 An exploded view of the hinge in a space-coiled extension arm with top vibration absorption and a gapless hinge, provided as an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the top platform in a space-coiled extension arm that absorbs vibration at the top and uses a gapless hinge, provided as an embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the internal structure of an electromagnetic active power vibration absorber in a spatial spiral extension arm that uses a gapless hinge and top vibration absorption, as provided in an embodiment of the present invention.

[0034] In the attached diagram: 1-Top platform; 11-Top cover; 12-Acceleration sensor; 13-Electromagnetic active vibration absorber; 131-Diaphragm spring; 132-Permanent magnet; 133-Outer shell; 134-Coil; 135-Coil sleeve; 14-Bracket; 15-Connecting screw; 16-Top plate; 2-Rotating extension arm; 21-Horizontal bar; 22-Vertical bar; 23-Cable; 24-No-contact hinge; 241-Vertical bar connector; 242-V-type connector; 243-Cable connection hole; 244-Bearing; 245-Fixing screw; 3-Base. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0037] like Figures 1 to 2 , Figure 4 The diagram shown illustrates a structural design of a top-shoulder, vibration-absorbing, space-coiled extendable arm with a gapless hinge, according to an embodiment of the present invention. The arm includes:

[0038] Top platform 1 and base 3;

[0039] A coiled extension arm 2 is installed between the top platform 1 and the base 3;

[0040] The top platform 1 includes an acceleration sensor 12 and an electromagnetic active power vibration absorber 13, which generate movement relative to the base 3 to apply bending and torsional torques to compensate for the dynamic deformation movement of the coiled extension arm 2.

[0041] The coiled extension arm 2 includes a gapless hinge 24 for eliminating hinge gaps.

[0042] In one embodiment of the present invention, the top-mounted vibration-absorbing and gapless hinged spatial coiled extension arm addresses the shortcomings of the prior art by providing an electromagnetic active power vibration absorber 13, which can be subjected to bending and torsional torques from the top platform 1 to compensate for the dynamic deformation of the coiled extension arm 2. At the same time, 24 is provided in the coiled extension arm 2 as a connecting structure to eliminate hinge gaps and enhance the overall rigidity of the coiled extension arm 2.

[0043] This device can apply active vibration suppression and eliminate hinge gaps. Compared with the existing spatial coiled extension structure, it greatly improves the dynamic stability and overall stiffness of the extended arm after deployment, effectively improves the dynamic pointing accuracy of the load, is easy to implement, has high reliability of the mechanism and its components, can be adapted to a large number of control algorithms, can be combined with the application of various hardware, has low manufacturing cost, high engineering feasibility, and has good application prospects.

[0044] like Figure 2 As shown, in a preferred embodiment of the present invention, the coiled extension arm 2 includes:

[0045] A triangular crossbar, wherein the triangular crossbar has multiple layers, and each layer of the triangular crossbar consists of three crossbars 21 and three non-contact gap hinges 24;

[0046] The longitudinal rod 22 has three members, and the triangular crossbar is connected to the longitudinal rod 22 by a non-contact gap hinge 24;

[0047] Cable 23 is connected to the triangular crossbar of the adjacent layer.

[0048] The coiled extension arm 2 serves as the main support structure. During the launch phase, it retracts into the satellite platform and fully extends when in orbit. The coiled extension arm 2 includes several layers of triangular cross frames, which are connected into a whole by longitudinal bars 22 and cables 23. The triangular cross frames are specifically equilateral triangular cross frames. Each layer consists of three non-contact gap hinges 24 and three cross bars 21. There are three longitudinal bars 22, which pass through the holes of the non-contact gap hinges 24. The cables 23 are diagonally fixed between adjacent triangular cross frames.

[0049] The longitudinal bar 22 can be made of titanium-nickel alloy, which has high elasticity and strong bending deformation capacity. The three crossbars 21 are connected to each other at the apex of the triangular section by a non-contact gap hinge 24, and are connected to the longitudinal bar 22 and the cable 23 to provide lateral support for the longitudinal bar 22. The cable 23 is made of stainless steel wire rope, which can limit the diagonal displacement of the rectangular space between adjacent crossbars, bear prestress, and is in a relaxed state when retracted. When the coiled extension arm 2 is extended, it can improve the shear stiffness and torsional stiffness.

[0050] like Figure 3 As shown, in another preferred embodiment of the present invention, the contactless gap hinge 24 includes:

[0051] V-shaped connector 242, wherein a cable connection hole 243 is provided on the V-shaped connector 242, and the cable 23 passes through the V-shaped connector 242 for connection;

[0052] The longitudinal rod connector 241 mates with the V-shaped connector 242 and is connected to the longitudinal rod 22;

[0053] The bearing 244 is installed in the V-shaped connector 242 and is axially fixed to the V-shaped connector 242. The fixing screw 245 passes through the bearing 244 and is threadedly engaged with the longitudinal rod connector 241. The longitudinal rod connector 241 and the fixing screw 245 form an integral unit and can rotate relative to the V-shaped connector 242.

[0054] The V-shaped connector 242 has through holes on both sides for connecting to the crossbar 21. The crossbar 21 can be fixed to the V-shaped connector 242 with M2 screws. The V-shaped connector 242 also has cable connection holes 243 for connecting the cable 23. The outer ring of the bearing 244 mates with the middle hole of the V-shaped connector 242. The middle hole is stepped, and the bearing 244 is axially fixed using a variable radius structure. Simultaneously, the outer ring of the bearing 244 needs to be glued to the middle hole of the V-shaped connector 242 to completely fix them together, thus preventing the V-shaped connector 242 from becoming stuck. When axial movement occurs at 42, the fixing screw 245 passes through the inner ring of the bearing 244 and engages with the screw hole on the longitudinal rod connector 241. After tightening, the entire assembly formed by the longitudinal rod connector 241 and the fixing screw 245 can rotate relative to the V-shaped connector 242. Due to the fit between the inner and outer diameters of the bearing 244, there is no gap in either the axial or radial direction of the gapless hinge 24. This allows the entire gapless hinge 24 to have only a degree of rotational freedom along the radial direction of the outer circle of the coiled extension arm 2, which can improve the overall rigidity of the device and enhance its vibration resistance.

[0055] like Figure 4 As shown, in a preferred embodiment of the present invention, the top platform 1 includes:

[0056] Top cover 11;

[0057] Electromagnetic active power vibration absorber 13, three of which are installed on the top cover 11 in an equilateral triangular shape, consistent with the triangular crossbar;

[0058] Accelerometer 12, three of which are provided, are mounted on the electromagnetic active power vibration absorber 13 via bracket 14, and are used to measure the vibration amplitude of the top platform 1 in three directions;

[0059] The upper plate 16 is mounted on the top cover 11, and the coiled extension arm 2 is connected to the upper plate 16.

[0060] The side length of the electromagnetic active vibration absorber 13 is the same as the length of the crossbar 21. The axial configuration direction can be obtained by rotating the cross section of the coiled extension arm 2 counterclockwise by 60° along the Z-axis. The acceleration sensor 12 is mounted on the electromagnetic active vibration absorber 13 through the bracket 14. The bracket 14 is connected to the electromagnetic active vibration absorber 13 through the connecting screw 15. Its measurement direction is along the axial direction of the electromagnetic active vibration absorber 13. The three degrees of freedom vibration of the top of the coiled extension arm 2 can be obtained by measurement. The three electromagnetic active vibration absorbers 13 can accurately configure the output force through the algorithm to realize the movement of the top platform 1 relative to the base 3, namely translation along the X-axis, translation along the Y-axis and torsion around the Z-axis, thereby achieving the purpose of active vibration suppression.

[0061] like Figure 5 As shown, in a preferred embodiment of the present invention, the electromagnetic active vibration absorber 13 includes:

[0062] Casing 133;

[0063] A coil sleeve 135 is axially mounted inside a housing 133, and a coil 134 is installed in the coil sleeve 135.

[0064] A permanent magnet 132 is installed axially inside a housing 133. Both ends of the permanent magnet 132 are connected to the housing 133 via diaphragm springs 131. There is a gap between the permanent magnet 132 and the inner wall of the coil 134.

[0065] The mass of the permanent magnet 132 is close to that of the outer shell 133. Both the permanent magnet 132 and the coil sleeve 135 are installed axially inside the coil sleeve 135. A coil 134 of a certain diameter (specifically 0.45 mm) is wound in the groove of the coil sleeve 135. There is a certain gap (specifically 1 mm) between its inner wall and the permanent magnet 132. The two ends of the permanent magnet 132 are connected to the outer shell 133 through diaphragm springs 131 to prevent the permanent magnet 132 from shifting laterally during movement and to ensure that the permanent magnet 132 always moves in the axial direction. When current flows through the coil 134, due to the action of electromagnetic force, the permanent magnet 132 moves relative to the electromagnetic active vibration absorber 13 and outputs a reaction force, thereby causing the electromagnetic active vibration absorber 13 to drive the top cover 11 and the upper plate 16 to move relative to the base 3, achieving the effect of active vibration suppression.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A spatial spiral extension arm with top vibration absorption and a gapless hinge, characterized in that, include: Top platform (1) and base (3); A coiled extension arm (2) is installed between the top platform (1) and the base (3); The top platform (1) includes an acceleration sensor (12) and an electromagnetic active power vibration absorber (13) to generate motion relative to the base (3) to apply bending and torsional torques to compensate for the dynamic deformation motion of the coiled extension arm (2). The coiled extension arm (2) includes a gapless hinge (24) for eliminating hinge gaps; The coiled extension arm (2) includes: A triangular crossbar, wherein the triangular crossbar has multiple layers, each layer of the triangular crossbar consists of three crossbars (21) and three non-contact gap hinges (24); The longitudinal bar (22) has three members, and the triangular crossbar is connected to the longitudinal bar (22) by a non-contact gap hinge (24); Cable (23) is connected to the triangular crossbeam of the adjacent layer; The top platform (1) includes: Top cover (11); Electromagnetic active power vibration absorber (13), three of which are installed on the top cover (11) in an equilateral triangle shape, consistent with the triangular cross frame; Accelerometer (12), three of the acceleration sensors (12) are provided. The acceleration sensors (12) are mounted on the electromagnetic active power vibration absorber (13) by bracket (14) and are used to measure the vibration amplitude of the top platform (1) in three directions. The upper top plate (16) is mounted on the top cover (11), and the coiled extension arm (2) is connected to the upper top plate (16); The electromagnetic active vibration absorber (13) includes: Outer shell (133); A coil sleeve (135) is axially mounted inside a housing (133), and a coil (134) is installed in the coil sleeve (135). A permanent magnet (132) is installed axially inside a housing (133). The two ends of the permanent magnet (132) are connected to the housing (133) via diaphragm springs (131). There is a gap between the permanent magnet (132) and the inner wall of the coil (134).

2. The spatial spiral extension arm with top vibration absorption and a gapless hinge according to claim 1, characterized in that, The contactless gap hinge (24) includes: V-shaped connector (242), wherein a cable connection hole (243) is provided on the V-shaped connector (242), and the cable (23) passes through the V-shaped connector (242) for connection; The longitudinal rod connector (241) cooperates with the V-shaped connector (242) and is connected to the longitudinal rod (22); The bearing (244) is installed in the V-shaped connector (242) and is axially fixed to the V-shaped connector (242). The fixing screw (245) passes through the bearing (244) and is threadedly engaged with the longitudinal rod connector (241). The longitudinal rod connector (241) and the fixing screw (245) form a whole that can rotate relative to the V-shaped connector (242).

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