Humanoid pole and wire dual actuation deployable membrane structure and method of making

Abstract

The present application relates to the technical field of aerospace structure, and particularly relates to a human-shaped rod and wire rope double-driven foldable membrane structure and a manufacturing method thereof, which can improve the shape precision of an antenna reflecting surface on the basis of increasing the effective aperture of the antenna, save the transportation cost of the antenna and improve the working efficiency of the antenna. The human-shaped rod and the wire rope are used to realize double driving, and the structure has the characteristics of lightweight, large folding, high shape precision and the like. Two driving devices are used in the whole structure for the first time, and the elastic force of the human-shaped rod after deformation provides the driving force in the unfolding process; the tensioned wire rope passes through three trapezoidal strips and adjusts the positions and postures of the three strips in the unfolding process, so that the unfolded membrane shape is more flat. The structure of the present application improves the shape precision of the antenna reflecting surface on the basis of increasing the effective aperture of the antenna, saves the transportation cost of the antenna and improves the working efficiency of the antenna, and has great application prospect in the field of aerospace.

Description

Technical Field

[0001] This invention relates to the field of aerospace structural technology, specifically to a foldable thin-film structure driven by both a human-shaped rod and a rope, and its fabrication method. Background Technology

[0002] With the deepening exploration of outer space and the rapid development of aerospace technology, space deployable antennas used on spacecraft such as satellites and space stations are constantly evolving towards larger size, greater precision, and lighter weight. Space folding structures are a new type of structure that has emerged with the innovation of aerospace technology, characterized by high rigidity, high storage capacity, and high geometric stability. This structure is stored in a folded state within the payload bay of each spacecraft during ground testing and launch; when the spacecraft is positioned in its working orbit, it receives a deployment command from the ground center, and the drive unit unfolds it into a pre-designed large and complex shape. Most of the space deployable antenna structures studied in the past have failed to simultaneously achieve a good folding-to-spread ratio and surface accuracy; therefore, it is necessary to study the drive unit and membrane structure of such space folding structures.

[0003] In practical engineering, key parameters are often used as evaluation indicators to describe the performance of a target. The same applies to antenna applications, where main performance parameters include mass, deflection ratio, and surface accuracy.

[0004] The most representative rigid reflector antenna currently is the Sunflower antenna developed by TRW. Rigid reflector antennas generally consist of a central hub and several solid curved surfaces, and are typically classified according to the different structures of these solid curved surfaces. Figure 1 The image shows the folded and unfolded states of a sunflower-shaped rigid reflector antenna. This type of rigid reflector antenna has a relatively simple structure. Each panel is connected to a central hub, and folding and unfolding are achieved by rotating vertically around the center. The position and direction of rotation of the hinges need to be determined based on the position of each panel during unfolding to avoid interference between components during movement. A truss is arranged behind each panel to improve the overall structural rigidity and antenna surface accuracy. Folding is achieved through hinges between the reflectors. The effective aperture of the antenna is 4.9m, and the folded aperture and height are 2.15m and 1.8m, respectively.

[0005] Rigid reflector antennas, such as those shaped like sunflowers, offer high density, structural stability, and uniform temperature field, making them suitable for frequencies above 40 GHz. However, their areal density is greater than that of mesh reflector antennas, which in turn is greater than that of inflatable deployable antennas. This larger mass translates to greater inertial forces during deployment and significantly higher spacecraft power consumption. Furthermore, the main structure of sunflower antennas is a solid panel, and due to the complexity of their mechanical construction and the limitations of their collapsible envelope size, the aperture of this type of high-precision antenna will not exceed 10 m, and its fold-down ratio is relatively low. Summary of the Invention

[0006] In view of this, the present invention provides a foldable thin film structure driven by both a human-shaped rod and a rope, and a method for manufacturing the same, which can improve the surface accuracy of the antenna reflector while increasing the effective aperture of the antenna, saving antenna transportation costs and improving antenna working efficiency.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A foldable membrane structure driven by both human-shaped rods and ropes includes a central release structure, human-shaped rods, connectors, carbon rods, paper hinges, a membrane, pulleys, and ropes. The membrane and human-shaped rods are connected by paper hinges, and two human-shaped rods are bonded to the membrane to form trapezoidal strips. Carbon rods are mounted on the trapezoidal strips. The central release structure includes an inner cylinder, an outer cylinder, a latch, and a base. The connector has holes, one end of which connects to the carbon rods on the trapezoidal strips, and the other end connects to the ropes, acting as a soft hinge in the entire structure. Multiple trapezoidal strips are arranged in order of length from shortest to longest. Two strands of rope extend from the central release structure, and each strand passes through the hole of the connector at one end of the strip and is connected to a weight via the pulley. The latch is used to lock the inner and outer cylinders of the central release structure. The gap between the inner and outer cylinders of the central release structure is used to store the trapezoidal strips in the folded state. When the latch is opened, the outer cylinder opens outward under the action of gravity, and the human-shaped rods in the inner and outer cylinders drive the membrane from the folded state to the unfolded state.

[0009] The human-shaped rod consists of a straight surface and two curved surfaces, with the two curved surfaces being symmetrical.

[0010] The film is a polyimide film.

[0011] The structure includes three trapezoidal strips.

[0012] The present invention also provides a manufacturing method for fabricating the structure of the present invention, comprising the following steps:

[0013] The film is laid on the mold, and the mold and test bench are fixed with screws. The paper hinge and carbon rod are glued together with epoxy resin. The mold consists of four trapezoidal small molds. The mold has a vertical rectangular groove, a square groove above the carbon rod, and a threaded hole. The vertical rectangular groove is used to mark the position of the carbon rod in the trapezoidal strip. The square groove above the carbon rod is used to place the paper hinge that connects the film and the human-shaped rod. The threaded hole is used to fix the mold and the test bench.

[0014] Use epoxy resin to connect the carbon rod, paper hinge, and polyimide film together. Lift the film and slide the human-shaped rod into the groove in the mold so that the edge of the polyimide film is aligned with the straight edge of the human-shaped rod. Then, use epoxy resin to bond the human-shaped rod and the film together.

[0015] Arrange the trapezoidal strips from shortest to longest, thread the rope through the hole on the connector, connect one end to the central release structure, and hang a weight on the other end to complete the production.

[0016] Beneficial effects:

[0017] 1. This invention achieves dual-drive via a human-shaped rod and a tensioned rope, featuring lightweight construction, a large folding ratio, and high surface accuracy, making it widely applicable to deployable antennas. For the first time in its structure, it utilizes two drive devices (the human-shaped rod and the tensioned rope). The elastic force of the deformed rod provides the driving force for the deployment process; the tensioned rope passes through three trapezoidal strips and adjusts their position and orientation during deployment, resulting in a smoother film surface after deployment. This invention increases the effective aperture of the antenna while improving the surface accuracy of the antenna reflector, saving on antenna transportation costs (reducing spacecraft power consumption) and improving antenna efficiency, thus showing great promise for applications in the aerospace field.

[0018] 2. The human-shaped rod used in this invention is a thin-walled tubular rod structure capable of retracting and unfolding, characterized by its small cross-sectional size, high rigidity, and reusability. Using the human-shaped rod as the driving device for the thin-film structure, replacing the rigid ribs in the original rigid surface reflector antenna, significantly reduces the overall weight of the structure and lowers the antenna's transportation costs. Furthermore, the human-shaped rod is made of composite materials using a special process, possessing high rigidity to support a larger area of ​​thin film, which also makes it possible to improve the structure's fold-to-spread ratio.

[0019] 3. This invention uses a rope with weights (heavy objects) to adjust the shape accuracy of the antenna after it is deployed. The rope passes through three trapezoidal strips of different sizes through a designed hinge. Its tension is applied to the thin film through the hinge, which makes the thin film structure reach the plane faster. When the thin film reaches the equilibrium state, the position error of each part of the film surface does not exceed 10mm.

[0020] 4. In this invention, epoxy resin is used to bond two human-shaped rods together with a thin film (analog antenna) to form a trapezoidal strip. Multiple trapezoidal strips are linked together by ropes, connectors, and a central release structure. The elastic force of the human-shaped rods when bent and the tension in the ropes can quickly unfold the entire structure, and the final film surface can achieve a shape accuracy of less than 10mm. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the unfolded configuration of a sunflower antenna.

[0022] Figure 2 This is a top view of the unfoldable thin film structure of the present invention.

[0023] Figure 3This is a folded three-dimensional view of the foldable thin film structure of the present invention.

[0024] Figure 4 This is a three-dimensional view of the unfoldable thin film structure of the present invention.

[0025] Figure 5 This is a schematic diagram of the human-shaped rod of the foldable thin film structure of the present invention.

[0026] Figure 6 This is a schematic diagram of the connector with the foldable thin film structure of the present invention.

[0027] Figure 7 This is a schematic diagram of the mold used to manufacture the foldable thin film structure of the present invention.

[0028] Among them, 1-central release structure, 2-human-shaped rod, 3-connector, 4-pulley, 5-rope, 6-carbon rod; 11-inner cylinder of central release structure, 12-outer cylinder of central release structure, 13-central release structure latch, 14-central release structure chassis; 21-straight surface of human-shaped rod, 22-curved surface of human-shaped rod; 71-vertical rectangular groove, 72-square groove above carbon rod, 73-threaded hole; 8-weight. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] This invention proposes a foldable thin film structure with dual drive by a human-shaped rod and a string. Figure 2 This is a top view of the unfoldable thin film structure of the present invention. Figure 3 This is a folded three-dimensional view of the foldable thin film structure of the present invention. Figure 4 This is a three-dimensional view of the unfolded foldable thin film structure of the present invention. The foldable thin film structure of the present invention includes a central release structure, a human-shaped rod, a connector, a carbon rod, a paper hinge, a thin film (analog antenna), a pulley, and a rope; the thin film and the human-shaped rod are connected by the paper hinge, and two human-shaped rods are bonded together with the thin film to form a trapezoidal strip, on which the carbon rod is provided. Figure 3 This is the posture of the foldable thin film structure before release, showing the central release structure, which includes an inner cylinder, an outer cylinder, a latch, and a base. The latch is used to lock the inner and outer cylinders of the central release structure, and the gap between the inner and outer cylinders of the central release structure is used to store the trapezoidal strip in the folded state (e.g., Figure 3 When the latch is opened, the outer cylinder opens outward under the influence of gravity, and the human-shaped rod inside the inner and outer cylinders pulls the membrane from... Figure 3 The folded state becomes Figure 4The unfolded state. The principle of the center release structure is that the inner and outer cylinders, which are tightened at both ends, bend the human-shaped rod. The deformed human-shaped rod has a large elastic force inside, and the elastic force after the human-shaped rod is deformed provides the driving force for the unfolding process. Furthermore, the film is a polyimide film.

[0031] Figure 5 This is a schematic diagram of the human-shaped rod of the foldable thin-film structure of the present invention. The human-shaped rod consists of a straight surface 21 and two symmetrical curved surfaces 22. In this invention, the human-shaped rod is used as the driving device for the thin-film structure, replacing the rigid ribs in the original rigid surface reflective antenna. This significantly reduces the overall weight of the structure, lowering the antenna's transportation costs. Furthermore, the human-shaped rod is made of composite material using a special process, possessing high rigidity to support a larger area of ​​thin film, which also makes it possible to improve the structure's folding-out ratio. The human-shaped rod is described in detail in patent 202311558433.4.

[0032] Multiple trapezoidal strips are arranged in ascending order of length. Two strands of cord extend from the central release structure, each strand passing through a hole in a connector at one end of the strip before being connected to a weight via a pulley. In this embodiment, the weight is a 0.4 kg weight. The connector is as follows... Figure 6 As shown, in this embodiment, the connector is a 3D printed part made of soft material. The connector has holes, one end of which is connected to a carbon rod on a trapezoidal strip, and the other end is connected to a wire, acting as a soft hinge in the entire structure. The structure of this embodiment includes three trapezoidal strips.

[0033] In summary, this invention is the first to use two driving devices (a human-shaped rod and a tensioned rope). The elastic force of the deformed human-shaped rod provides the driving force for the deployment process. The tensioned rope passes through three trapezoidal strips and adjusts the position and orientation of the three strips during deployment, making the unfolded film surface smoother. Specifically, a rope with weights is used to control the surface accuracy of the antenna after deployment. The rope passes through three trapezoidal strips of different sizes through a designed hinge, and its tension acts on the film through the hinge, allowing the film structure to reach the plane more quickly. When the film reaches equilibrium, the maximum positional error at various points on the film surface does not exceed 10mm.

[0034] The entire structure of this embodiment weighs approximately 50g. When the human-shaped rod is bent, the elastic force and tension in the rope can quickly unfold the entire structure, achieving a folding-to-unfold ratio of 1:50. Furthermore, the final shape of the thin film does not differ by more than 10mm. It features lightweight, high folding-to-unfold ratio, and high surface accuracy, which can solve the current predicament of rigid reflector antennas.

[0035] The present invention also provides a manufacturing method for fabricating the foldable thin film structure with dual drive of humanoid rod and rope, comprising the following steps:

[0036] The film is laid on the 3D-printed mold (e.g.) Figure 7 As shown, screws are used to fix the mold and the test bench (the mold has an M6 threaded hole). Epoxy resin is used to bond the paper hinge and carbon rod (3mm*0.5mm cross-section) together (the mold has a groove to hold the model airplane paper hinge and carbon rod). The mold consists of four trapezoidal small molds. The mold has a vertical rectangular groove, a square groove above the carbon rod, and a threaded hole. The vertical rectangular groove is used to mark the position of the carbon rod in the trapezoidal strip. The square groove above the carbon rod is used to hold the paper hinge connecting the film and the human-shaped rod. The threaded hole is used to fix the mold and the test bench. In this embodiment, an M6 threaded hole is used.

[0037] Use epoxy resin to connect the carbon rod, paper hinge, and polyimide film together. Lift the film and slide the human-shaped rod into the groove in the mold, so that the edge of the polyimide film is aligned with the straight edge of the human-shaped rod. Then, use epoxy resin to bond the human-shaped rod and the film together.

[0038] Arrange the three trapezoidal strips in order of length from shortest to longest. Thread the string through the hole on the connector, connect one end to the central release structure, and hang a 0.4kg weight on the other end to complete the assembly.

[0039] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A foldable thin-film structure driven by both a human-shaped rod and a rope, characterized in that, The system includes a central release structure, humanoid rods, connectors, carbon rods, paper hinges, a membrane, pulleys, and ropes. The membrane and humanoid rods are connected by paper hinges, and two humanoid rods are bonded to the membrane to form a trapezoidal strip. Carbon rods are mounted on the trapezoidal strip. The central release structure includes an inner cylinder, an outer cylinder, a latch, and a base. The connector has holes, one end of which connects to the carbon rod on the trapezoidal strip, and the other end connects to the rope, acting as a flexible hinge in the entire structure. Multiple trapezoidal strips are arranged in order of length from shortest to longest. Two strands of rope extend from the central release structure, and each strand passes through the hole of the connector at one end of the strip and is connected to a weight via the pulley. The latch is used to lock the inner and outer cylinders of the central release structure. The gap between the inner and outer cylinders of the central release structure is used to store the trapezoidal strip in its folded state. When the latch is opened, the outer cylinder opens outward under the action of gravity, and the humanoid rods inside the inner and outer cylinders drive the membrane from the folded state to the unfolded state.

2. The structure as described in claim 1, characterized in that, The human-shaped rod consists of a straight surface and two curved surfaces, which are symmetrical.

3. The structure as described in claim 1 or 2, characterized in that, The film is a polyimide film.

4. The structure as described in claim 1 or 2, characterized in that, The structure comprises three trapezoidal strips.

5. A manufacturing method, characterized in that, The method for fabricating the structure as described in any one of claims 1-4 includes the following steps: The film is laid on the mold, and the mold and test bench are fixed with screws. The paper hinge and carbon rod are glued together with epoxy resin. The mold consists of four trapezoidal small molds. The mold has a vertical rectangular groove, a square groove above the carbon rod, and a threaded hole. The vertical rectangular groove is used to mark the position of the carbon rod in the trapezoidal strip. The square groove above the carbon rod is used to place the paper hinge that connects the film and the human-shaped rod. The threaded hole is used to fix the mold and the test bench. Use epoxy resin to connect the carbon rod, paper hinge, and film together. Lift the film and slide the human-shaped rod into the groove in the mold so that the edge of the film and the straight edge of the human-shaped rod are aligned. Then, use epoxy resin to bond the human-shaped rod and the film together. Arrange the trapezoidal strips from shortest to longest, thread the rope through the hole on the connector, connect one end to the central release structure, and hang a weight on the other end to complete the production.

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