Hybrid shear-hinge unit array type multi-layer perimeter truss foldable antenna mechanism

Abstract

The application provides a kind of based on hybrid shear hinge unit array multi-layer perimeter truss foldable antenna mechanism, and the basic unit is single-degree-of-freedom hybrid basic foldable unit, each single-degree-of-freedom hybrid basic foldable unit is formed by two first basic foldable units and second basic foldable units projected as pentagon by sharing adjacent units, and N single-degree-of-freedom hybrid basic foldable units are connected with each other by sharing adjacent shear hinge units and nodes and are distributed in a circumferential array.The mechanism is a multi-layer perimeter truss foldable antenna mechanism, each layer node has a height difference, and is high outside and low inside, which can fit the parabolic surface required by the foldable antenna mechanism, further improve the stiffness of the reflecting surface, and the size of the truss foldable antenna formed by adjusting the length of the connecting rod and the shear hinge connecting rod and the number of basic foldable units can adapt to different space needs, with high structural symmetry, strong adaptability, high stiffness, good reliability and other characteristics.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and more specifically to a multi-layer peripheral truss unfolding antenna mechanism based on a hybrid shear-hinged unit array. Background Technology

[0002] With the continuous development of my country's aerospace industry, the technology in the aerospace field is also constantly breaking through, and spaceborne antennas, as transmission tools, are receiving more and more attention. One important application of space deployment mechanisms in the aerospace field is as a support and deployment mechanism for large-aperture spaceborne antennas. Among them, peripheral truss wires are a key research focus for various countries. Peripheral ring truss space deployable antennas are currently the most numerous type of space deployable antenna in orbit. Compared with other antenna structures, they have the characteristics of a large convergence ratio and light weight, and have a wide range of applications.

[0003] Peripheral truss deployable antennas consist of front and rear cable nets providing tension, a retractable support mechanism, and a metal reflector. The retractable support mechanism determines the antenna's aperture, while the tension provided by the front and rear cable nets effectively ensures the overall structural rigidity of the antenna. Currently, the support mechanism of peripheral truss antennas mainly uses a scissor-type mechanism, which features simple structure and high rigidity. Within a certain range, increasing the aperture will not change the antenna's structural form, nor will the mass increase proportionally. This is currently an ideal structural form for large deployable antennas and has excellent development prospects. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a single-freedom multi-constrained folding and unfolding unit and a large-scale spatial folding and unfolding mechanism composed of it, which features a simple structure, large folding ratio, high rigidity, good unfolding performance, strong adaptability, high reliability, and easy control. Its overall structure is simple, and all kinematic pairs are revolute pairs, making it easy to manufacture.

[0005] This invention provides a multi-layer peripheral truss folding antenna mechanism based on a hybrid scissor-hinged unit array, comprising N single-degree-of-freedom hybrid basic folding units, where N is an integer greater than or equal to three. Each single-degree-of-freedom hybrid basic folding unit includes a first basic folding unit and a second basic folding unit. The N single-degree-of-freedom hybrid basic folding units are arranged in a circumferential array. The projections of the first and second basic folding units are both pentagons. The first basic folding unit is located in the inner circle of the antenna mechanism, and the second basic folding unit is located in the outer circle of the antenna mechanism.

[0006] The first basic folding unit includes five sets of shear hinge units and ten nodes. The ten nodes include five upper-level projection nodes with projections on the upper layer and five lower-level projection nodes with projections on the lower layer. Each of the five sets of shear hinge units is formed by two identical shear hinge rods connected together. The two identical shear hinge rods are connected by a revolute joint to form an asymmetrical X-shape. The two ends of each shear hinge rod are connected to the upper-level projection node and the lower-level projection node respectively through a revolute joint. The axes of the five revolute joints of each set of shear hinge units are parallel and perpendicular to the plane where the shear hinge rods are located.

[0007] The second basic folding unit includes two sets of linkage units, four sets of scissor hinge units, and ten nodes. The two sets of linkage units are the first linkage unit and the second linkage unit. The first linkage unit and the second linkage unit each include two structurally identical linkages. The two linkages are connected to each other and to the nodes by means of revolute joints. The axes of the revolute joints of each linkage unit are parallel and perpendicular to the plane in which the linkage is located. Each set of scissor hinge units includes two structurally identical scissor hinge linkages. The two scissor hinge linkages are connected by revolute joints to form an X shape. The two scissor hinge linkages are connected to the nodes by means of revolute joints. The ten nodes include five upper-level projection nodes with projections on the upper layer and five lower-level projection nodes with projections on the lower layer.

[0008] The fourth hinge unit of the first basic folding unit and the first hinge unit of the second basic folding unit share the same nodes at both ends, thus forming a complete single-degree-of-freedom hybrid basic folding unit. That is, the upper and lower projections of each single-degree-of-freedom hybrid basic folding unit each include eight nodes. N single-degree-of-freedom hybrid basic folding units are formed by sharing the circumferential array of adjacent units. The first hinge unit, the second hinge unit, and the second hinge unit of the first basic folding unit of the first single-degree-of-freedom hybrid basic folding unit share the fifth hinge unit, the fourth hinge unit, the third hinge unit, and the nodes at both ends of the first basic folding unit of the second single-degree-of-freedom hybrid basic folding unit. The N single-degree-of-freedom hybrid basic folding units are connected in sequence to form a multi-layer peripheral truss folding antenna mechanism based on a hybrid hinge unit array.

[0009] Preferably, the five sets of shear hinge units in the first basic folding unit are a first shear hinge unit, a second shear hinge unit, a third shear hinge unit, a fourth shear hinge unit, and a fifth shear hinge unit; the upper-level projection nodes are a first upper node, a second upper node, a third upper node, a fourth upper node, and a fifth upper node; the lower-level projection nodes are a first lower node, a second lower node, a third lower node, a fourth lower node, and a fifth lower node; the first upper node, the second upper node, the third lower node, and the fourth lower node are respectively connected to the first shear hinge unit. The four endpoints are connected; the second upper node, the third upper node, the second lower node, and the third lower node are respectively connected to the four endpoints of the second scissor hinge unit; the third upper node, the fourth upper node, the third lower node, and the fourth lower node are respectively connected to the four endpoints of the third scissor hinge unit; the fourth upper node, the fifth upper node, the fourth lower node, and the fifth lower node are respectively connected to the four endpoints of the fourth scissor hinge unit; the fifth upper node, the first upper node, the fifth lower node, and the first lower node are respectively connected to the four endpoints of the fifth scissor hinge unit.

[0010] Preferably, the four sets of shear hinge units of the second basic folding unit are a first shear hinge unit, a second shear hinge unit, a third shear hinge unit, and a fourth shear hinge unit; the two sets of linkage units are a first linkage unit and a second linkage unit, and the upper projection nodes are a first upper node, a second upper node, a third upper node, a fourth upper node, and a fifth upper node; the lower projection nodes are a first lower node, a second lower node, a third lower node, a fourth lower node, and a fifth lower node; the first upper node and the second upper node, as well as the first lower node and the second lower node, are respectively connected to the first... The four endpoints of the scissor hinge unit are connected; the second upper node, the third upper node, the second lower node, and the third lower node are respectively connected to the four endpoints of the second scissor hinge unit; the third upper node, the fourth upper node, the third lower node, and the fourth lower node are respectively connected to the four endpoints of the first link unit and the second link unit; the fourth upper node, the fifth upper node, the fourth lower node, and the fifth lower node are respectively connected to the four endpoints of the third scissor hinge unit; the fifth upper node, the first upper node, the fifth lower node, and the first lower node are respectively connected to the four endpoints of the fourth scissor hinge unit.

[0011] Preferably, the second and fifth shear hinge units of the first basic folding unit have identical structures; the third and fourth shear hinge units of the first basic folding unit have identical structures; the first and fourth shear hinge units of the second basic folding unit have identical structures; and the second and third shear hinge units of the second basic folding unit have identical structures. Furthermore, the first and second nodes of the first basic folding unit have identical structures; the third and fifth nodes of the first basic folding unit have identical structures; and the second and fifth nodes of the second basic folding unit have identical structures; and the third and fourth nodes of the second basic folding unit have identical structures.

[0012] Preferably, each of the outer surfaces of the node is provided with three slots, the rotation axis of each slot is parallel to the upper and lower bottom surfaces, and each slot has a through hole for placing a rotating pair; the slot directions are the directions from each vertex of the projection of the unfolded antenna mechanism to the other three vertices; the length from the center of the node to the rotation axis of each slot is equal, and the length from the center hole of the three shear hinge connecting rods connected to the node to the end hole near the node is the same.

[0013] Preferably, the size of the assembled truss folding antenna is changed by adjusting the lengths of the connecting rods and the shear hinge connecting rods, as well as the number of single-degree-of-freedom basic folding units.

[0014] Preferably, the X-shaped structure of the innermost vertical shear hinge unit is a symmetrical structure, while the X-shaped structures of the remaining shear hinge units are asymmetrical structures.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) The present invention is a multi-layer peripheral truss folding antenna mechanism. Through the design of the pentagonal projection structure of the inner and outer layers, the overall stiffness is greatly improved. Furthermore, it has good mechanical properties and a high folding ratio, thus giving the antenna mechanism the potential to form a large antenna of the hundred-meter level.

[0017] (2) The present invention is a single-degree-of-freedom spatial basic deployable unit, that is, multiple units can be deployed and retracted with just one drive. It has good deployment performance, high reliability, and can meet the needs of various application scenarios.

[0018] (3) The present invention has a simple overall structure. All kinematic pairs between the mechanisms are connected by rotating pairs. Each rotating pair is universal and easy to manufacture. It can save manufacturing costs, reduce the waste of manpower and material resources, and facilitate large-scale production.

[0019] (4) This invention has a high degree of structural symmetry. By assembling multiple deployable units, a double-layer peripheral truss folding antenna mechanism of arbitrary size can be formed. Each layer of the node has a height difference, and the outer layer is higher than the inner layer. This can fit the parabolic surface required by the folding antenna mechanism, further improving the stiffness of the reflector. By adjusting the length of the connecting rod and the shear hinge connecting rod, as well as the number of basic folding units, the size of the assembled truss folding antenna can be changed, which can adapt to different aerospace requirements and thus meet various aviation needs. Attached Figure Description

[0020] Figure 1 This is a simplified three-dimensional schematic diagram of the fully deployed state of the multi-layer peripheral truss folding antenna mechanism based on the hybrid shear-hinged unit array of the present invention.

[0021] Figure 2 for Figure 1 A simplified diagram illustrating the projection in its fully extended state;

[0022] Figure 3 for Figure 1 A simplified frontal view of the fully unfolded state;

[0023] Figure 4 for Figure 1 A simplified 3D diagram of the normal unfolded state;

[0024] Figure 5 for Figure 1 A simplified 3D diagram of the fully retracted state;

[0025] Figure 6 This is a simplified three-dimensional schematic diagram of the fully unfolded state of the single-degree-of-freedom hybrid basic unfolding unit of the present invention;

[0026] Figure 7 for Figure 5 A simplified 3D diagram of the normal unfolded state;

[0027] Figure 8 for Figure 5 A simplified 3D diagram of the fully retracted state;

[0028] Figure 9 This is a simplified three-dimensional schematic diagram of the conventional unfolded state of the single-degree-of-freedom basic unfolding unit of the present invention, which is projected as a pentagon.

[0029] Figure 10 This is a simplified three-dimensional schematic diagram of the conventional unfolded state of the basic folding unit C of the single degree of freedom, which is projected as a pentagon in this invention.

[0030] Figure 11 This is a simplified three-dimensional schematic diagram of the inner ring nodes of the present invention;

[0031] Figure 12 This is a simplified three-dimensional schematic diagram of the second ring of nodes in this invention;

[0032] Figure 13 This is a simplified three-dimensional schematic diagram of the third ring node of the present invention;

[0033] Figure 14 This is a simplified three-dimensional schematic diagram of the outer ring nodes of the present invention;

[0034] Figure 15 This is a simplified three-dimensional schematic diagram of the shear hinge unit of the present invention.

[0035] The following are descriptions of some of the attached figures:

[0036] 100 - Single-degree-of-freedom hybrid basic folding element, 200 - First basic folding element, 300 - Second basic folding element, 301-303 - Revolute joint, 1 - Fifth node of the first basic folding element, 2 - First node of the first basic folding element, 3 - Fourth node of the first basic folding element, 4 - Second node of the first basic folding element, 5 - Third node of the first basic folding element, 6 - Fifth shear hinge element of the first basic folding element, 7 - Fourth shear hinge element of the first basic folding element, 8 - First shear hinge element of the first basic folding element, 9 - First basic folding element The third scissor hinge unit of the unit, 10 - the second scissor hinge unit of the first basic folding and unfolding unit, 11 - the fourth node of the second basic folding and unfolding unit, 12 - the fifth node of the second basic folding and unfolding unit, 13 - the first node of the second basic folding and unfolding unit, 14 - the link unit, 15 - the second node of the second basic folding and unfolding unit, 16 - the third node of the second basic folding and unfolding unit, 17 - the third scissor hinge unit of the second basic folding and unfolding unit, 18 - the fourth scissor hinge unit of the second basic folding and unfolding unit, 19 - the first scissor hinge unit of the second basic folding and unfolding unit, 20 - the second scissor hinge unit of the second basic folding and unfolding unit. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0038] In the description of this invention, it should be understood that the terms "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0039] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0040] like Figures 1-5 As shown, the present invention discloses a multi-layer peripheral truss folding antenna mechanism based on a hybrid scissor-hinged unit array, which includes N single-degree-of-freedom hybrid basic folding units 100, where N is greater than or equal to 3. In this embodiment, N is 20. The multiple single-degree-of-freedom hybrid basic folding units 100 are interconnected by sharing adjacent scissor-hinged units and nodes and are arranged in a circumferential array to form a specific folding antenna mechanism. Figure 3 A side view of the antenna mechanism 100 is shown.

[0041] Each single-degree-of-freedom hybrid basic unit 100 includes a first basic unit 200 located in the inner circle and a second basic unit 300 located in the outer circle. The first basic unit 200 and the second basic unit 300 together constitute a single-degree-of-freedom hybrid basic unit 100. Figure 2 As can be seen, the first basic folding unit 200 and the second basic folding unit 300 diagonally behind it together form a single single-degree-of-freedom hybrid basic folding unit 100. The first basic folding unit 200 is located in the inner circle, and the second basic folding unit 300 is located in the outer circle.

[0042] In this configuration, when multiple single-degree-of-freedom hybrid basic folding units 100 are connected, the first hinge unit 8, the second hinge unit 10 of the first basic folding unit 200 of the first single-degree-of-freedom hybrid basic folding unit 100, and the second hinge unit 20 of the second basic folding unit 300 share the fifth hinge unit 6 of the first basic folding unit 200 and the fourth hinge unit 18 and the third hinge unit 17 of the second basic folding unit 300, as well as their respective end nodes. The remaining single-degree-of-freedom hybrid basic folding units 100 sequentially share the aforementioned units with adjacent single-degree-of-freedom hybrid basic folding units 100, thereby forming a complete folding antenna mechanism. In the figure, α is the included angle of the center of each single-degree-of-freedom hybrid basic folding unit 100, where α = 180° / N.

[0043] like Figures 6-8 As shown, the single-degree-of-freedom hybrid basic folding unit 100 includes two pentagonal projected basic folding units: a first basic folding unit 200 and a second basic folding unit 300. The first basic folding unit 200 and the second basic folding unit 300 are formed by sharing adjacent units. The first basic folding unit 200 is located in the inner circle of the single-degree-of-freedom hybrid basic folding unit 100, and the second basic folding unit 300 is located in the outer circle of the single-degree-of-freedom hybrid basic folding unit 100. They share a portion of the shear hinge unit and endpoints. Specifically, the fourth shear hinge unit 7 of the first basic folding unit 200 and the first shear hinge unit 19 of the second basic folding unit 300, along with their two end nodes, are shared.

[0044] like Figure 9As shown, the first basic folding unit 200 includes five sets of scissor hinge units and ten nodes. In the first basic folding unit 200, the five sets of scissor hinge units are respectively the first scissor hinge unit, the second scissor hinge unit, the third scissor hinge unit, the fourth scissor hinge unit, and the fifth scissor hinge unit; the upper-level projection nodes are respectively the first upper node, the second upper node, the third upper node, the fourth upper node, and the fifth upper node; the lower-level projection nodes are respectively the first lower node, the second lower node, the third lower node, the fourth lower node, and the fifth lower node; the first upper node, the second upper node, the next lower node, and the second lower node are respectively connected to the first scissor hinge unit. The four endpoints are connected; the second upper node, the third upper node, the second lower node, and the third lower node are respectively connected to the four endpoints of the second scissor hinge unit; the third upper node, the fourth upper node, the third lower node, and the fourth lower node are respectively connected to the four endpoints of the third scissor hinge unit; the fourth upper node, the fifth upper node, the fourth lower node, and the fifth lower node are respectively connected to the four endpoints of the fourth scissor hinge unit; the fifth upper node, the first upper node, the fifth lower node, and the first lower node are respectively connected to the four endpoints of the fifth scissor hinge unit. For ease of illustration, only some nodes are labeled in the figure.

[0045] In the diagram, the top and bottom markers are omitted; the upper and lower nodes on the projection are collectively referred to as "node number". For example, the first node 2 of the first basic folding unit actually includes the first upper node and the first lower node of the first basic folding unit. The second scissor hinge unit 10 and the fifth scissor hinge unit 6 of the first basic folding unit have identical structures; the third scissor hinge unit 9 and the fourth scissor hinge unit 7 of the first basic folding unit have identical structures; the second scissor hinge unit 20 and the third scissor hinge unit 17 of the second basic folding unit have identical structures; the first scissor hinge unit 19 and the fourth scissor hinge unit 18 of the second basic folding unit have identical structures; the first node 2 and the second node 4 of the first basic folding unit have identical structures; the third node 5 and the fifth node 1 of the first basic folding unit have identical structures; the second node 15 and the fifth node 12 of the second basic folding unit have identical structures; and the third node 16 and the fourth node 11 of the second basic folding unit have identical structures. The fourth node 3 of the first basic folding unit is its own independent structure.

[0046] In the first basic folding unit 200, the distance from the center to both ends of the first shearing unit 8 is equal: L1 = 100mm, meaning the first shearing unit 8 of the first basic folding unit 200 is a symmetrical X-shaped structure. The distances from the center to both ends of the second shearing unit 10 and the fifth shearing unit 6 of the first basic folding unit 200 are not equal, with the short side and long side being L1 = 100mm and L2 = 120mm respectively. The distances from the center to both ends of the third shearing unit 9 and the fourth shearing unit 7 of the first basic folding unit 200 are not equal, with the short side and long side being L2 = 120mm and L3 = 135.4mm respectively.

[0047] like Figure 10 As shown, the second basic folding unit 300 includes two sets of linkage units, four sets of hinge units (two of which are shared with the first basic folding unit 200), and ten nodes (two of which are shared with the first basic folding unit 200, connecting the upper and lower nodes of the two shared hinge units). In the second basic folding unit 300, the four hinge units are the first hinge unit, the second hinge unit, the third hinge unit, and the fourth hinge unit; the two linkage units are the first linkage unit and the second linkage unit, both formed by connecting two linkages via a revolute joint 303. The two linkage units are located at the upper and lower parts of the outermost layer of the antenna, respectively. Except for the two outermost linkage units, all others are connected by hinge units.

[0048] The upper-layer projection nodes are the first upper node, the second upper node, the third upper node, the fourth upper node, and the fifth upper node; the lower-layer projection nodes are the first lower node, the second lower node, the third lower node, the fourth lower node, and the fifth lower node. The first upper node, the second upper node, the first lower node, and the second lower node are connected to the four endpoints of the first scissor hinge unit, respectively. The second upper node, the third upper node, the second lower node, and the third lower node are connected to the four endpoints of the second scissor hinge unit, respectively. The third upper node, the fourth upper node, the third lower node, and the fourth lower node are connected to the four endpoints of the first link unit and the second link unit, respectively. The fourth upper node, the fifth upper node, the fourth lower node, and the fifth lower node are connected to the four endpoints of the third scissor hinge unit, respectively. The fifth upper node, the first upper node, the fifth lower node, and the first lower node are connected to the four endpoints of the fourth scissor hinge unit, respectively. The fifth node of the first layer and the first node of the second layer are connected to the four endpoints of the fourth scissor hinge unit, respectively. The distances from the centers to both ends of the second scissor hinge unit 20 and the third scissor hinge unit 17 of the second basic folding unit 300 are also unequal, with the short and long sides being L3 = 135.4 mm and L4 = 150 mm, respectively, and the connecting rod length being L5 = 240 mm. For ease of illustration, only some nodes are labeled in the figure. The distances from the centers to both ends of the first scissor hinge unit 19 and the fourth scissor hinge unit 18 of the second basic folding unit 300 are equal, and they are the same as the first scissor hinge unit 8 of the first basic folding unit 200.

[0049] Because some of the shear hinge units and nodes of the second basic folding unit 300 are shared with the first basic folding unit 200, the second basic folding unit 300 only needs to be provided with two additional sets of shear hinge units and six nodes. Specifically, the fourth shear hinge unit 7 of the first basic folding unit 200 is also used as the first shear hinge unit 19 of the second basic folding unit 300. At the same time, the two sets of upper and lower nodes connected to both ends of this shear hinge unit are also shared.

[0050] like Figure 11 The diagram shown is a simplified 3D representation of the innermost upper and lower layer nodes. For these innermost nodes, the thickness is 5mm, and the distance from the node center to the axis of each rotary joint is n = 10mm. The included angle between adjacent rotary joint axes is 360°*(N-2) / N.

[0051] like Figure 12 In the schematic diagram of the second ring of nodes from the inside to the outside, the thickness of the second ring of nodes is 5mm, the distance from the center of the node to the axis of each rotation joint is n = 10mm, and the included angle between adjacent rotation joint axes is 360°*(N-2) / N.

[0052] In this embodiment, space is reserved at the innermost node for mounting the rotating joints of the other mechanisms. In fact, in other embodiments, the structure of the innermost node can be exactly the same as the structure of the second ring node from the inside out.

[0053] like Figure 13 In the simplified three-dimensional schematic diagram of the third ring of nodes from the inside out, the thickness of the third ring of nodes is 5mm, the distance from the center of the node to the axis of each rotation joint is n=14.6mm, β=41.1°, and the included angle between adjacent rotation joint axes is 2β.

[0054] like Figure 14 In the simplified 3D schematic diagram of the outermost ring nodes shown, for the upper and lower layers of the outermost ring nodes, the thickness of this ring node is 5mm, and the distance from the center of the node to the axis of each rotation joint is n = 10mm. The included angle between adjacent rotation joint axes is 360° - (360° * (N - 2) / N).

[0055] like Figure 15 In the schematic diagram of the three-dimensional scissor unit shown, each group of scissor units in each basic folding unit is connected by two identical scissor links. Each scissor link has three holes at both ends and in the middle for placing a rotating joint. The two identical scissor links are connected by a rotating joint 302 in the middle to form an X shape. Except for the first scissor unit 8 of the first basic folding unit 200 and the first scissor unit 19 of the second basic folding unit 300, which are symmetrical X shapes, the X shapes of the remaining scissor units are not symmetrical X shapes, but rather X shapes that are shorter inside and longer outside, thus meeting the antenna folding requirements. In the embodiment, both ends of the scissor links and both ends of the connecting rods are connected to the nodes by rotating joints 301. Two scissor links are connected by rotating joints 302, and two connecting rods are connected by rotating joints 303. In the embodiment of the present invention, all rotating joints 301, 302, and 303 can be rotated and connected between the connecting rods by means of pins or pins.

[0056] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A multi-layer peripheral truss folding antenna mechanism based on a hybrid shear-hinged unit array, characterized in that: It includes N single-degree-of-freedom hybrid basic folding units, where N is an integer greater than or equal to three. Each single-degree-of-freedom hybrid basic folding unit includes a first basic folding unit and a second basic folding unit. The N single-degree-of-freedom hybrid basic folding units are arranged in a circumferential array. The projections of the first and second basic folding units are both pentagons. The first basic folding unit is located in the inner circle of the antenna mechanism, and the second basic folding unit is located in the outer circle of the antenna mechanism. The first basic folding unit includes five sets of shear hinge units and ten nodes. The ten nodes include five upper-layer projection nodes with projections on the upper layer and five lower-layer projection nodes with projections on the lower layer. Each of the five sets of shear hinge units is formed by two identical shear hinge rods connected together. The two identical shear hinge rods are connected by a revolute joint to form an X shape. The two ends of each shear hinge rod are connected to the upper-layer projection node and the lower-layer projection node respectively through a revolute joint. The axes of the five revolute joints of each set of shear hinge units are parallel and perpendicular to the plane where the shear hinge rods are located. The second basic folding unit includes two sets of linkage units, four sets of scissor hinge units, and ten nodes. The two sets of linkage units are the first linkage unit and the second linkage unit. The first linkage unit and the second linkage unit each include two structurally identical linkages. The two linkages are connected to each other and to the nodes by means of revolute joints. The axes of the revolute joints of each linkage unit are parallel and perpendicular to the plane in which the linkage is located. Each set of scissor hinge units includes two structurally identical scissor hinge linkages. The two scissor hinge linkages are connected by revolute joints to form an X shape. The two scissor hinge linkages are connected to the nodes by means of revolute joints. The ten nodes include five upper-level projection nodes with projections on the upper layer and five lower-level projection nodes with projections on the lower layer. The fourth hinge unit of the first basic folding unit and the first hinge unit of the second basic folding unit share the same nodes at both ends, thus forming a complete single-degree-of-freedom hybrid basic folding unit. That is, the upper and lower projections of each single-degree-of-freedom hybrid basic folding unit each include eight nodes. N single-degree-of-freedom hybrid basic folding units are formed by sharing the circumferential array of adjacent units. The second hinge unit, the third hinge unit of the first basic folding unit of the first single-degree-of-freedom hybrid basic folding unit and the second hinge unit of the second basic folding unit share the fifth hinge unit of the first basic folding unit and the fourth hinge unit, the third hinge unit of the second basic folding unit and the nodes at both ends. N single-degree-of-freedom hybrid basic folding units are connected in sequence to form a multi-layer peripheral truss folding antenna mechanism. The five sets of shear hinge units in the first basic folding unit are the first shear hinge unit, the second shear hinge unit, the third shear hinge unit, the fourth shear hinge unit, and the fifth shear hinge unit; the upper-level projection nodes are the first upper node, the second upper node, the third upper node, the fourth upper node, and the fifth upper node; the lower-level projection nodes are the first lower node, the second lower node, the third lower node, the fourth lower node, and the fifth lower node; the first upper node, the second upper node, the third lower node, and the fourth lower node are respectively connected to the four shear hinge units of the first shear hinge unit. Endpoint connections: The second upper node, the third upper node, the second lower node, and the third lower node are respectively connected to the four endpoints of the second scissor hinge unit; the third upper node, the fourth upper node, the third lower node, and the fourth lower node are respectively connected to the four endpoints of the third scissor hinge unit; the fourth upper node, the fifth upper node, the fourth lower node, and the fifth lower node are respectively connected to the four endpoints of the fourth scissor hinge unit; the fifth upper node, the first upper node, the fifth lower node, and the first lower node are respectively connected to the four endpoints of the fifth scissor hinge unit. The second basic folding unit comprises four sets of shear hinge units: a first shear hinge unit, a second shear hinge unit, a third shear hinge unit, and a fourth shear hinge unit; two sets of linkage units: a first linkage unit and a second linkage unit; upper-level projected nodes: a first upper node, a second upper node, a third upper node, a fourth upper node, and a fifth upper node; lower-level projected nodes: a first lower node, a second lower node, a third lower node, a fourth lower node, and a fifth lower node; and the first upper node, the second upper node, the first lower node, and the second lower node are respectively connected to the first shear hinge. The four endpoints of the unit are connected; the second upper node, the third upper node, the second lower node, and the third lower node are respectively connected to the four endpoints of the second scissor hinge unit; the third upper node, the fourth upper node, the third lower node, and the fourth lower node are respectively connected to the four endpoints of the first link unit and the second link unit; the fourth upper node, the fifth upper node, the fourth lower node, and the fifth lower node are respectively connected to the four endpoints of the third scissor hinge unit; the fifth upper node, the first upper node, the fifth lower node, and the first lower node are respectively connected to the four endpoints of the fourth scissor hinge unit.

2. The multi-layer peripheral truss folding antenna mechanism based on a hybrid shear-hinged unit array as described in claim 1, characterized in that: The second and fifth shear hinge units of the first basic folding unit have identical structures; the third and fourth shear hinge units of the first basic folding unit have identical structures; the second and third shear hinge units of the second basic folding unit have identical structures; the first and fourth shear hinge units of the second basic folding unit have identical structures; the first and second nodes of the first basic folding unit have identical structures; the third and fifth nodes of the first basic folding unit have identical structures; the second and fifth nodes of the second basic folding unit have identical structures; and the third and fourth nodes of the second basic folding unit have identical structures.

3. The multi-layer peripheral truss folding antenna mechanism based on a hybrid shear-hinged unit array as described in claim 1, characterized in that: The size of the assembled truss folding antenna can be changed by adjusting the lengths of the connecting rods and shear hinges, as well as the number of single-degree-of-freedom basic folding units.

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