Stable deployment control method based on smart composite pod rod

Abstract

The application discloses a stable unfolding control method based on an intelligent composite material pod rod, and belongs to the technical field of controllable unfolding.The method comprises the following steps: pasting two heating films one and two on a pod rod half piece in sequence, and arranging a winding shaft, and realizing extrusion winding of the pod rod by the winding shaft; pasting an arc piece on the heating film one, and the glass transition temperature of the arc piece is higher than that of the pod rod half piece; the heating film two is powered on first during unfolding, after the pod rod segment pasted with the heating film two is unfolded, the heating film one is powered on, the part of the heating film which is not pasted with the arc piece first reaches the glass transition temperature of the material, and is unfolded under the driving of the shape memory function, and the part pasted with the arc piece has a higher glass transition temperature, and continues to be heated to realize stable unfolding.The application can be used under the condition that power supply energy and power supply lines of a spacecraft are insufficient, and overcomes the problem of insufficient power supply energy of the spacecraft.

Description

Technical Field

[0001] This invention belongs to the field of controllable deployment technology, specifically relating to a stable deployment control method based on intelligent composite material bean pod stalks. Background Technology

[0002] Traditional deployable pod-like structures are thin-walled tubular rods made of resin-based composite materials that can be flattened, rolled up, and retracted under external force; they are also known as lens-type tubular space extenders. When retracting, a common method is to use a mechanical structure to compress and wind the thin-walled shell, combined with a locking mechanism, to achieve the pod-like rod's retraction and locking. When deploying, the locking mechanism unlocks, utilizing the elastic potential energy of the thin-walled shell to rapidly unfold the pod-like rod. This deployment process involves significant impact and poor stability. As a space deployable structure, the pod-like rod is widely used in the aerospace field due to its simple structure and high retraction ratio, showing broad application prospects in large-scale space mesh antennas, deep space exploration, space robots, and solar sail masts.

[0003] Shape Memory Polymer Composites (SMPCs) are a novel type of smart material that undergoes active deformation through external stimuli. Under different external environmental stimuli (heat, light, magnetism, etc.), they can be shaped into temporary shapes. When the stimuli and external forces are removed, they remain in the temporary state, exhibiting the ability to retain temporary deformation. When subjected to the same external stimuli again, they can return to the initial shape, thus demonstrating the ability to remember the initial shape.

[0004] The number of circuits and voltages that a satellite can provide to a spacecraft are limited. When large pods based on smart composite materials are required, insufficient onboard energy may occur.

[0005] Cross-section of bean pod stem as shown Figure 1 As shown, it features vertical and horizontal symmetry, and is composed of two upper and lower halves 1 glued together. The cross-sectional shape of a single piece is Ω-shaped, specifically including three parts: a horizontal section 11, two concave arc sections 12 on both sides, and a central arc section 13. In traditional pod-like structures, both upper and lower halves 1 are made of fiber-reinforced resin-based composite materials. The pod-like stalk is flattened and wound onto a cylindrical reel, and a locking mechanism is used to achieve the stalk's retraction and locking. During on-orbit operation, there are two common ways for the pod-like stalk to unfold: one is by unlocking the locking mechanism, where the pod-like stalk relies on its stored elastic potential energy to achieve rapid release, which has the disadvantages of large impact and uncontrollable unfolding; the other is by relying on a traditional mechanical structure to achieve the winding and unfolding of the pod-like stalk, which has the disadvantages of complex structure, large weight, and easy jamming of the mechanical structure. Summary of the Invention

[0006] This invention provides a stable deployment control method for a smart composite material pod rod, which aims to solve the following problems: (1) The elastic pod rod structure has a large impact on the spacecraft during deployment, and the deployment controllability and stability are poor; (2) Existing mechanical structures are heavy, complex in design, and prone to jamming; (3) When the elastic pod rod is deployed under load, the sudden release of elastic potential energy will cause the end reel or load to be placed on the pod rod, and the lever arm will increase when the reel is lifted, resulting in incomplete deployment of the pod rod; (4) It is used when the spacecraft's power supply energy and power supply line are insufficient.

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

[0008] A method for stable deployment control of bean pod stalks based on intelligent composite materials, the method being as follows:

[0009] Two heating films, one and two heating films, are pasted onto half of the bean pod stalk in sequence, and a roller is arranged to extrude and wind the bean pod stalk.

[0010] An arc-shaped piece is attached to the heating film, wherein the glass transition temperature of the arc-shaped piece is higher than that of the half-piece of the pod stalk.

[0011] The specific folding process of the present invention is as follows: When unfolding, the second heating film is energized first. After the pod stem segment with the second heating film attached is unfolded, the first heating film is energized. After the first heating film is energized, the part of the heating film without the attached arc piece first reaches the glass transition temperature of the material and unfolds under the drive of the shape memory function. The part with the attached arc piece has a higher glass transition temperature and continues to be heated to achieve stable unfolding.

[0012] Furthermore, both the pod stalk halves and the arc-shaped pieces are made of materials with shape memory properties.

[0013] Furthermore, the materials of the bean pod stalk halves and the arc-shaped pieces are smart polymers or composite materials thereof; the smart polymers include epoxy resins and cyanate ester resins; the composite materials are made from raw materials including carbon fibers, glass fibers or aramid fibers.

[0014] Furthermore, the pod stalk halves are prepared by traditional vacuum hot pressing or by additive manufacturing technology.

[0015] Furthermore, other excitation methods are adopted: when thermal excitation is used, the heating element is an embedded resistance wire, an embedded electric heating film, or an externally attached electric heating film; when magnetic excitation is used, ferromagnetic materials are filled into the smart polymer composite material; when electric excitation is used, single-walled or multi-walled carbon nanotubes, graphene, carbon black, carbon nanopaper, carbon nanofibers, or hybrid particles are doped into the smart polymer composite material; if a combined driving method is adopted, the particles doped into the smart composite material system should be two or more combinations of the above.

[0016] Furthermore, the cross-section of the pod stalk can be replaced with C-shaped, circular, concave hexagonal, corrugated plate, elliptical, rounded rhomboid, hexagonal honeycomb, or herringbone cross-sections.

[0017] The advantages of this invention over the prior art are as follows:

[0018] (1) The unfolding method proposed in this invention can greatly reduce the lever arm when lifting the roll;

[0019] (2) The stable unfolding of the pod stalk structure is achieved based on intelligent composite materials. The pod stalk does not require a complex mechanical structure when unfolding. It is lightweight and simple in structure, avoiding the problem of easy jamming that may occur with mechanical structures.

[0020] (3) This invention can be used when the power supply energy and power supply lines of spacecraft are insufficient, thus overcoming the problem of insufficient power supply energy of spacecraft;

[0021] (4) By attaching additional arc pieces 4 to control the unfolding path of the pod rod, the lever arm of lifting the roll during unfolding is greatly reduced, the required restoring force of the pod rod is smaller, and the pod rod can be stably unfolded.

[0022] (5) This invention achieves stable and controllable deployment of the pod rod structure through different preparation or excitation methods, reduces the impact of the pod rod on the spacecraft during deployment, and also overcomes the problems of uncontrollable deployment path and poor stability during the deployment of elastic pod rod. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a traditional bean pod stalk cross-section;

[0024] Figure 2 A three-dimensional diagram of a traditional bean pod stalk;

[0025] Figure 3 This is a schematic diagram of Comparative Example 1;

[0026] Figure 4 This is a schematic diagram of Comparative Example 2;

[0027] Figure 5 This is a schematic diagram of Comparative Example 3;

[0028] Figure 6 This is a schematic diagram for Comparative Example 4;

[0029] Figure 7 This is a schematic diagram of the present invention;

[0030] Figure 8 A diagram illustrating the failure of an elastic pod stem to unfold;

[0031] Figure 9 This is a diagram illustrating the unfolded phenomena of the present invention;

[0032] Figure 10 This is a schematic diagram of the unfolding process in Example 1;

[0033] Figure 11 This is a schematic diagram for cases where the cross-section of the bean pod stalk has other shapes.

[0034] Among them, 1-half of bean pod stalk, 11-horizontal section, 12-inward concave arc sections on both sides, 13-middle arc section, 21-heating film one, 22-heating film two, 23-heating film three, 24-heating film four, 3-roller, 4-arc plate. Detailed Implementation

[0035] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0036] Comparative Example 1:

[0037] Comparative Example 1 of the present invention is a stable unfolding control method for a smart composite material pod stalk. The inner half of the pod stalk 1 is made of a smart polymer composite material, and the outer half of the pod stalk 1 is made of a fiber-reinforced resin-based composite material.

[0038] Take thermally excited smart polymer composites as an example. At room temperature, the material is in a glassy state, possessing high stiffness and elastic modulus. When its temperature exceeds its glass transition temperature, the material softens and enters a rubbery state. At this point, the smart polymer composite can be shaped into a temporary shape under external force. By lowering the temperature of the smart polymer composite while maintaining the external force, once the temperature falls below its glass transition temperature, the material can remember this temporary shape and remain fixed in that form, exhibiting high stiffness and elastic modulus. When the temperature of the smart polymer composite is raised again, the material can spontaneously return to its initial shape, thus demonstrating a shape-memory function.

[0039] In this comparative example, two heating films, 21 and 22, are sequentially attached to half of the pod stem 1, and a roller 3 is arranged. When the pod stem needs to be retracted, heating film 21 is first energized and heated. When the temperature of half of the pod stem 1, made of intelligent polymer composite material, is higher than the glass transition temperature of the material, the pod stem is squeezed and wound by the roller 3. When heating film 21 is retracted, the material temperature is lowered to below the glass transition temperature. Then, heating film 22 is wound in the same way. After winding, while maintaining external force, the temperature of the pod stem is lowered to below the glass transition temperature. At this point, the external force is removed, and the pod stem remains in the retracted state without the need for additional locking.

[0040] During deployment, the heating film 22 is first energized. After the temperature of the pod rod half piece 1, made of intelligent polymer composite material, exceeds the glass transition temperature of the material, the pod rod will slowly unfold to its initial straight state under the action of shape memory function. This process will limit the rapid opening of the elastic pod rod half piece 1, made of fiber-reinforced resin matrix composite material, and reduce the impact on the spacecraft during the deployment process. After the first section is deployed, the heating film 21 is energized again to achieve stable and controllable deployment of the pod rod.

[0041] Comparative Example 2:

[0042] Comparative Example 2 of this invention describes a stable deployment control method for a bean pod stem based on a smart composite material. Both the upper and lower halves of the bean pod stem are made of a smart polymer composite material. Taking a thermally excited smart polymer composite material as an example, two heating films are attached to each of the two bean pod stem halves 1.

[0043] The retraction and unfolding process in this embodiment is similar to that of Comparative Example 1. Compared to Comparative Example 1, this comparative example lacks the elastic pod-shaped half-piece 1 made of fiber-reinforced resin matrix composite material. The unfolding process is controlled by a smart polymer composite material, making it more stable, reliable, slow, and impact-free. Furthermore, the unfolding speed can be controlled to a certain extent by the heating power of the heating film and the material heating time.

[0044] Comparative Example 3:

[0045] Comparative Example 3 of the present invention is a stable unfolding control method for pod stalks based on intelligent composite materials. The inner half of the pod stalk 1 is made of intelligent polymer composite material, and the outer half of the pod stalk 1 is made of fiber-reinforced resin-based composite material.

[0046] Unlike Comparative Example 1, the number of heating films on the pod stem was changed from two to four, or even more. Compared to Comparative Example 1, Comparative Example 3 uses more heating films, resulting in a shorter unfolding length of the pod stem during a single heating cycle and higher stability. When there are enough heating films, the pod stem wrapped around the roll gradually unwraps as it is heated in segments. The roll can then slide outwards from the surface of the pod stem, greatly enhancing the stability of the unfolding and achieving controllable unfolding. This avoids the risk of the portion of the pod stem closer to the roll 3 unfolding first when the heating film 21 is too long, disrupting the stable unfolding sequence and leading to unfolding failure.

[0047] Comparative Example 4:

[0048] Based on Comparative Example 3, Comparative Example 4 was obtained by preparing both pod stalk halves 1 from intelligent polymer composite materials, and heating films were correspondingly attached to the pod stalk halves 1. (See schematic diagram below.) Figure 6 .

[0049] Example 1:

[0050] A method for stable deployment control of bean pod stalks based on intelligent composite materials, the method being as follows:

[0051] Two heating films, 21 and 22, are sequentially pasted onto half of the bean pod stalk 1, and a roller 3 is arranged to extrude and wind the bean pod stalk.

[0052] An arc-shaped piece 4 made of intelligent polymer composite material is attached to the heating film 21, as shown in the schematic diagram. Figure 7 The glass transition temperature of the arc-shaped piece 4 is higher than that of the pod stalk half piece 1.

[0053] The unfolding process of this invention is similar to that of Comparative Example 1. During unfolding, heating film 22 is energized first. After the pod stem segment with heating film 22 attached is unfolded, heating film 21 is then energized. When heating film 21 is energized, the portion of heating film 21 without the attached arc piece 4 reaches the glass transition temperature of the material first and unfolds under the drive of shape memory. The portion with the arc piece 4 attached has a higher glass transition temperature and requires further heating for stable unfolding. The attachment of the arc piece 4 ensures stable and controllable unfolding of the pod stem, while preventing the portion of the pod stem closer to the roll 3 from unfolding first when the heating film 21 is too long, thus disrupting the stable unfolding sequence and causing unfolding failure. A schematic diagram of unfolding failure is shown below. Figure 8 .

[0054] The materials of the pod stalk half 1 and the arc plate 4 possess shape memory properties. The intelligent polymer composite material is a novel intelligent material made from intelligent polymers and their composites. The intelligent polymers include shape memory resins such as epoxy and cyanate esters, which can actively deform and return to a preset initial shape while maintaining high stiffness under external stimuli such as heat, light, or magnetism, thus possessing shape memory function. The composite materials are made from raw materials including carbon fiber, glass fiber, or aramid fiber, which can increase the driving force of deformation when the intelligent polymer deforms, ensure the stability of the structure made from the intelligent composite material, and enhance its fracture toughness.

[0055] In addition to the pod stalk half piece 1 being made of smart polymer composite material, other parts of the half piece, such as the middle arc section 13 or the middle arc section and the two concave arc sections 12 on both sides, can also be made of smart polymer composite material as needed, while other parts are made of fiber-reinforced resin-based composite material.

[0056] The pod stalk half-piece 1 is prepared by traditional vacuum hot pressing of composite materials or by additive manufacturing technology.

[0057] The heating film attached in the embodiments of the present invention is for thermal excitation of the material. Magnetic or electrical excitation can also be applied. When thermal excitation is used, the heating element can be an embedded resistance wire, an embedded electric heating film, an externally attached electric heating film, etc. When magnetic excitation is used, ferromagnetic materials, such as iron oxide particles, can be filled into the intelligent polymer composite material. When electrical excitation is used, single-walled or multi-walled carbon nanotubes, graphene, carbon black, carbon nanopaper, carbon nanofibers, or hybrid particles can be doped into the intelligent polymer composite material. If a combined driving method is used, the particles doped into the intelligent composite material system should be a combination of two or more of the above.

[0058] This invention can also replace the cross-section of the bean pod stalk with C-shaped, circular, concave hexagonal, corrugated plate, elliptical, rounded rhomboid, hexagonal honeycomb, herringbone, and other cross-sections, such as... Figure 11 As shown.

[0059] The stable unfolding control method proposed in this invention can control the unfolding time and speed by adjusting the glass transition temperature of the material and the heating power of the heating film, combined with the cross-sectional dimensions and thickness of the pod stalk structure. The unfolding time can reach the minute level, while the traditional elastic unfolding method usually has an unfolding time in the second level, which will bring large impacts and poor unfolding stability.

[0060] Compared with existing technologies, this invention addresses engineering problems that are prone to occur during practical use. When the end of the elastic pod stem is under load, i.e., when the scroll 3 is unfurled, the disorderly unfurled pod stem, under the weight of the scroll, is prone to the following phenomenon: the load rests on the pod stem, and the restoring force of the pod stem is insufficient to overcome the weight of the scroll and lift it, nor is it sufficient to drag the scroll along the unfurling direction, resulting in incomplete unfurling of the pod stem. Figure 8 As shown.

[0061] Similarly, in Comparative Examples 1 and 2, because the heating film is longer, when the last section of the heating film heats up, the entire pod stalk is heated, causing the pod stalk near the roll to extend prematurely, which easily leads to… Figure 8 The phenomenon of incomplete unfolding of the pod stems is observed. Comparative Examples 3 and 4 can solve this problem, but in practical applications, the energy supplied by the satellite to the spacecraft is limited. Given the limited power supply lines and fixed power supply voltage of the spacecraft, the number of heating films cannot be increased indefinitely, nor can the size of the heating films be arbitrarily changed. Therefore, Comparative Examples 3 and 4 are no longer applicable in this invention.

[0062] Specifically, when using large pod stalks based on smart composite materials, in order to achieve successful unfolding and avoid [missing information] Figure 8 The problem is that, due to the consistent power supply voltage, in order for each heating film to reach the glass transition temperature of the intelligent composite material, multiple heating films of approximately equal length need to be attached to the pod stem to achieve stable deployment of the pod stem, as shown in Comparative Examples 3 and 4. However, the power supply lines on the spacecraft cannot be increased indefinitely, so it is impossible to significantly increase the number of heating films. In addition, under the condition of consistent power supply voltage, if the deployment success rate is increased by increasing the length of heating film 22, heating film 23, and heating film 4 24 while decreasing the length of heating film 1 21, the temperature of heating film 22, heating film 23, and heating film 4 24 will be too low, failing to reach the glass transition temperature of the intelligent composite material. The solution proposed in this invention can solve the above two problems. Without increasing the number of heating films or changing the length of the heating films, the deployment process of the corresponding segment of heating film 1 21 is changed to ensure successful deployment of the pod stem. The proposed solution of this invention further improves the controllability of unfolding, and avoids the risk of unfolding failure caused by the part of the pod stem closer to the roller 3 unfolding first when the heating film is too long, which would disrupt the stable unfolding sequence of the pod stem.

[0063] The proposed solution eliminates the need for additional power supply lines; it only requires attaching a high-glass transition temperature smart polymer composite material to the pod stem. The length of the arc-shaped piece 4 near the pod and the glass transition temperature of the material can be flexibly adjusted based on the spool size, test requirements such as unfolding time, and test phenomena to meet spacecraft requirements. After attaching the arc-shaped piece 4, ensuring the final, stable rolling unfolding of the spool 3 is sufficient to meet the requirements. Under the control of this invention, no issues will occur during the pod stem unfolding process. Figure 8 The experimental phenomenon shown is that the end load roll 3 rests on the pod stem, which would normally cause the pod stem to unfold stably. During the unfolding process, the following phenomena occur: Figure 9 The unfolding phenomenon shown indicates that in this case, the lever arm is smaller when lifting the reel during the unfolding process of the pod stalk, and the required restoring force of the pod stalk is smaller, allowing the reel to be lifted to complete the unfolding. Alternatively, the reel can be dragged along the unfolding direction to complete the unfolding. The state of the pod stalk before unfolding is shown in the diagram. Figure 9 .

Claims

1. A stable unfolding control method based on intelligent composite material pod stalks, characterized in that: The method is as follows: Two heating films, one and two heating films, are pasted onto half of the bean pod stalk in sequence, and a roller is arranged to extrude and wind the bean pod stalk. An arc-shaped piece is attached to the heating film, wherein the glass transition temperature of the arc-shaped piece is higher than that of the half-piece of the pod stalk. The unfolding process is as follows: First, the second heating film is energized. After the pod stem segment with the second heating film attached is unfolded, the first heating film is energized. After the first heating film is energized, the part of the heating film without the attached arc piece first reaches the glass transition temperature of the material and unfolds under the drive of the shape memory function. The part with the attached arc piece has a higher glass transition temperature and needs to be heated to unfold stably. Both the pod stalk halves and the arc-shaped pieces are made of materials with shape memory properties.

2. The stable deployment control method based on intelligent composite material pod stalks according to claim 1, characterized in that: The materials of the pod stalk halves and the arc-shaped pieces are smart polymers or composite materials thereof; the smart polymers include epoxy resins and cyanate ester resins; the composite materials are made from raw materials including carbon fibers, glass fibers or aramid fibers.

3. The stable deployment control method based on intelligent composite material pod stalks according to claim 1, characterized in that: The pod stalk halves are prepared by traditional vacuum hot pressing or by additive manufacturing technology.

4. The stable deployment control method based on intelligent composite material pod stalks according to claim 1, characterized in that: Other excitation methods are adopted: when thermal excitation is used, the heating element is an embedded resistance wire, an embedded electric heating film, or an externally attached electric heating film; when magnetic excitation is used, ferromagnetic materials are filled into the smart polymer composite material; when electric excitation is used, single-walled or multi-walled carbon nanotubes, graphene, carbon black, carbon nanopaper, carbon nanofibers, or hybrid particles are doped into the smart polymer composite material; if a combined driving method is adopted, the particles doped into the smart composite material system should be two or more of the above combinations.

5. The stable deployment control method based on intelligent composite material pod stalks according to claim 1, characterized in that: Replace the cross-section of the pod stalk with a C-shaped, circular, concave hexagonal, corrugated plate, elliptical, rounded rhomboid, hexagonal honeycomb, or herringbone cross-section.

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