Stable unfolding control method based on intelligent composite material pod rod

Abstract

The invention 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 steps that a first heating film and a second heating film are sequentially pasted on a half piece of a pod rod, a reel is arranged, and extrusion winding of the pod rod is achieved through the reel; pasting an arc sheet on the heating film I, wherein the glass transition temperature of the arc sheet is higher than that of the pod rod half sheet; during unfolding, the second heating film is powered on firstly, after the pod rod section pasted with the second heating film is unfolded, the first heating film is powered on, the part, not pasted with the arc piece, of the heating film reaches the glass-transition temperature of the material firstly, and the part is heated and unfolded under driving of the shape memory function; the glass transition temperature of the part where the arc sheet is pasted is high, and stable unfolding is achieved through continuous heating. The system can be used under the condition that power supply energy and power supply lines of the spacecraft are insufficient, and the problem that the power supply energy of the spacecraft is insufficient is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of controllable deployment, and in particular relates to a stable deployment control method based on a pod rod made of intelligent composite materials. Background Art

[0002] The traditional deployable pod pole structure is a thin-walled tubular pole made of resin-based composite materials that can be flattened, curled and folded under external force. It is also called a lens-type tubular space extension arm. When folding, the common method is to use a mechanical structure to compress and wind the thin-walled shell, and cooperate with a certain locking mechanism to achieve the folding and locking of the pod pole; when unfolding, the locking mechanism is unlocked, and the elastic potential energy of the thin-walled shell is used to achieve the rapid unfolding of the pod pole. The unfolding process has a large impact and poor stability. As a space deployable structure, the pod pole is widely used in the aerospace field due to its simple structure and large storage ratio. It has broad application prospects in large space mesh antennas, deep space exploration, space robots, solar sail poles, etc.

[0003] Smart polymers and their composite materials (Shape Memory Polymer Composites, SMPCs) are a new type of smart material that can be actively deformed by external stimulation. Under different external environmental stimulations (heat, light, magnetism, etc.), they can be shaped into temporary shapes. When the stimulation and external force are removed, they still remain in the temporary state and have the ability to maintain temporary deformation; when subjected to the same external stimulation again, they can return to the initial shape, thus demonstrating the memory function of the initial shape.

[0004] The number of power supply circuits and voltages that a satellite can provide for a particular spacecraft are limited, and when large pod poles based on smart composite materials are needed, there will be a shortage of energy on board.

[0005] The cross section of the pod stem is as follows Figure 1 As shown, it has the characteristics of upper and lower symmetry and left and right symmetry. It is formed by gluing two upper and lower half pieces 1. The cross-section of the single piece is Ω-shaped, specifically including three parts: a horizontal section 11, concave arc sections 12 on both sides, and a middle arc section 13. The upper and lower half pieces 1 of the traditional bean pod rod structure are both made of fiber-reinforced resin-based composite materials. The bean pod rod is flattened and then wound on a cylindrical reel, and the locking mechanism is used to achieve the folding and locking of the bean pod rod. When working on track, there are two common ways to unfold the bean pod rod: one is to unlock the locking mechanism, and the bean pod rod relies on its own stored elastic potential energy to achieve rapid release, which has the disadvantages of large impact and uncontrollable unfolding; the other is to rely on the traditional mechanical structure to achieve the winding and unfolding of the bean pod rod. This method has the disadvantages of complex structure, heavy weight, and easy jamming of the mechanical structure. Summary of the invention

[0006] The present invention provides a stable deployment control method based on a pod rod of an intelligent composite material, the purpose of which is 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) the existing mechanical structure is heavy, complex in design, and easy to get stuck; (3) when the elastic pod rod is deployed with a load, the sudden release of elastic potential energy will cause the end reel or the load to rest on the pod rod, and the force arm will increase when the reel is lifted, resulting in incomplete deployment of the pod rod; (4) when used in the case of insufficient power supply energy and power supply lines for the spacecraft, the power supply energy of the spacecraft is insufficient.

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

[0008] A stable deployment control method based on a smart composite material pod rod, the method comprising:

[0009] Two heating films 1 and 2 are sequentially pasted on the half piece of bean pod stem, and a reel is arranged to realize the extrusion and winding of the bean pod stem by the reel;

[0010] Pasting a circular arc sheet on the first heating film, wherein the glass transition temperature of the circular arc sheet is higher than the glass transition temperature of the bean pod stem half sheet;

[0011] The folding process of the present invention is specifically as follows: when unfolding, the heating film 2 is energized first, and after the bean pod rod segment with the heating film 2 is unfolded, the heating film 1 is energized; after the heating film 1 is energized, the part of the heating film where the arc piece is not pasted first reaches the glass transition temperature of the material, and is heated and unfolded under the drive of the shape memory function, while the part where the arc piece is pasted has a higher glass transition temperature, and continues to be heated to achieve stable unfolding.

[0012] Furthermore, the materials of the bean pod stem half piece and the arc piece both have shape memory properties.

[0013] Furthermore, the material of the bean pod stem half piece and the arc piece is a smart polymer or a composite material thereof; the smart polymer includes epoxy resin and cyanate resin; the composite material is made of raw materials including carbon fiber, glass fiber or aramid fiber.

[0014] Furthermore, the bean pod stem half piece is prepared by a conventional vacuum hot pressing method or by using additive manufacturing technology.

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

[0016] Furthermore, the cross section of the pod rod is replaced with a C-shaped, circular, concave hexagonal, corrugated plate, elliptical, rounded diamond, hexagonal honeycomb or herringbone cross section.

[0017] The beneficial effects of the present invention compared to the prior art are:

[0018] (1) The unfolding method proposed by the present invention can greatly reduce the force arm when lifting the reel;

[0019] (2) The pod pole structure is stably unfolded based on the intelligent composite material. The pod pole does not require a complex mechanical structure when unfolding. It is light in weight and simple in structure, thus avoiding the problem of easy jamming of the mechanical structure.

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

[0021] (4) By attaching an additional arc piece 4 to control the unfolding path of the pod rod, the force arm of the lifting reel during unfolding is greatly reduced, and the required restoring force of the pod rod is smaller, which can ensure the stable unfolding of the pod rod;

[0022] (5) The present invention realizes stable and controllable deployment of the peapod rod structure through different preparation or excitation methods of the peapod rod, reduces the impact of the peapod rod on the spacecraft during the deployment process, and overcomes the problem of uncontrollable deployment path and poor stability during the deployment of the elastic peapod rod. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0024] Figure 2 It is a three-dimensional schematic diagram of a traditional bean pod pole;

[0025] Figure 3 It is a schematic diagram of comparative example 1;

[0026] Figure 4 It is a schematic diagram of comparative example 2;

[0027] Figure 5 It is a schematic diagram of comparative example 3;

[0028] Figure 6 It is a schematic diagram of Comparative Example 4;

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

[0030] Figure 8 Schematic diagram of the problems that may occur when the elastic pod rod is unfolded;

[0031] Fig. 9 It is the unfolding phenomenon diagram of the present invention;

[0032] Fig.10 This is a schematic diagram of the development process of Example 5;

[0033] Fig.11 Schematic diagram of the case where the cross section of the pod rod has other shapes.

[0034] Among them, 1-half piece of bean pod rod, 11-horizontal segment, 12-inwardly concave arc segments on both sides, 13-middle arc segment, 21-heating film one, 22-heating film two, 23-heating film three, 24-heating film four, 3-reel, 4-arc piece. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the protection scope of the present invention.

[0036] Comparative Example 1:

[0037] Comparative Example 1 of the present invention is based on a stable unfolding control method for a bean pod stem made of an intelligent composite material. The bean pod stem half piece 1 wound inside is made of an intelligent polymer composite material, and the bean pod stem half piece 1 wound outside is made of a fiber-reinforced resin-based composite material.

[0038] Take the thermally stimulated smart polymer composite material as an example. At room temperature, the material is in a glassy state with large stiffness and elastic modulus. When its own temperature exceeds the glass transition temperature of the material, the material becomes soft and in a rubbery state. At this time, the smart polymer composite material can be shaped into a temporary shape under the action of external force, and the temperature of the smart polymer composite material can be lowered while maintaining the external force. When the temperature is lower than its glass transition temperature, the material can remember the temporary shape and be fixed in this form, and has large stiffness and elastic modulus. When the temperature of the smart polymer composite material is raised again, the material can return to its initial shape by itself, thereby showing the memory function of the initial shape.

[0039] In this comparative example, two heating films 1 21 and 2 22 are sequentially attached to the bean pod stem half sheet 1, and a reel 3 is arranged. When the bean pod stem needs to be folded, the heating film 1 21 is first powered on for heating, and when the temperature of the bean pod stem half sheet 1 made of the intelligent polymer composite material is higher than the glass transition temperature of the material, the bean pod stem is squeezed and wound by the reel 3; when the heating film 1 21 section is folded, the material temperature is lowered to below the glass transition temperature; then the heating film 2 22 is wound in the same way; after winding, the temperature of the bean pod stem is lowered to below the glass transition temperature while maintaining the external force, and then the external force is removed, and the bean pod stem is kept in the wound and folded state without the need for additional locking.

[0040] When unfolding, the heating film 2 22 is energized first. After the temperature of the pod rod half piece 1 made of the intelligent polymer composite material is higher than the glass transition temperature of the material, the pod rod will slowly unfold to the initial straight state under the action of the shape memory function. This process will limit the rapid opening of the elastic pod rod half piece 1 made of the fiber-reinforced resin-based composite material, thereby reducing the impact on the spacecraft during the unfolding process. After the first stage of unfolding is completed, the heating film 1 21 continues to be energized to achieve stable and controllable unfolding of the pod rod.

[0041] Comparative Example 2:

[0042] Comparative Example 2 of the present invention is based on a stable unfolding control method of a bean pod rod made of a smart composite material, and the upper and lower pieces of the bean pod rod are both made of a smart polymer composite material. Accordingly, taking the thermally stimulated smart polymer composite material as an example, two heating films are attached to the two bean pod rod halves 1.

[0043] The folding and unfolding process of this embodiment is similar to that of comparative example 1. Compared with comparative example 1, since the elastic bean pod rod half piece 1 made of fiber-reinforced resin-based composite material is not used, the unfolding process is controlled by the intelligent polymer composite material, and the unfolding process is more stable and reliable, slow and impact-free. At the same time, the unfolding speed can also 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 based on a stable unfolding control method for a bean pod stem made of an intelligent composite material. The bean pod stem half piece 1 wound inside is made of an intelligent polymer composite material, and the bean pod stem half piece 1 wound outside is made of a fiber-reinforced resin-based composite material.

[0046] Unlike Comparative Example 1, the number of heating films on the pod rod is changed from two to four, or other larger numbers. Compared with Comparative Example 1, Comparative Example 3 uses more heating films, and the length of the pod rod when a single heating power is turned on is shorter and more stable. When the number of heating films is large enough, the pod rod wrapped around the reel gradually disperses from the pod rod as the segmented heating proceeds, and the reel can be attached to the surface of the pod rod and gradually slide outward, and the stability of the unfolding will be greatly enhanced, achieving controllable unfolding. This avoids the situation where the length of the heating film 21 is too long, and the part of the pod rod close to the reel 3 unfolds first, disrupting the stable unfolding order of the pod rod and bringing the risk of unfolding failure.

[0047] Comparative Example 4:

[0048] On the basis of comparative example 3, the two bean pod stem half pieces 1 of comparative example 3 are both made of the smart polymer composite material to obtain comparative example 4, and a heating film is correspondingly attached to the bean pod stem half piece 1, as shown in the schematic diagram Figure 5 .

[0049] Embodiment 1:

[0050] A stable deployment control method based on a smart composite material pod rod, the method comprising:

[0051] Two heating films 1 21 and 2 2 are sequentially attached to the bean pod stem half sheet 1, and a reel 3 is arranged to realize the extrusion and winding of the bean pod stem by using the reel 3;

[0052] The arc sheet 4 made of smart polymer composite material is pasted on the heating film 21, as shown in the schematic diagram. Figure 6 The glass transition temperature of the arc piece 4 is higher than the glass transition temperature of the bean pod stem half piece 1 .

[0053] The folding process of the present invention is similar to that of comparative example 1. When unfolding, the heating film 2 22 is energized first, and after the pod rod segment to which the heating film 22 is pasted is unfolded, the heating film 1 21 is energized. After the heating film 1 21 is energized, the portion of the heating film where the arc piece 4 is not pasted reaches the glass transition temperature of the material first, and is heated and unfolded under the drive of the shape memory function, while the portion to which the arc piece 4 is pasted has a higher glass transition temperature and needs to continue to be heated for stable unfolding. The pasting of the arc piece 4 realizes the stable and controllable unfolding of the pod rod, and at the same time avoids the situation where the heating film 1 21 is too long. When the heating film is heated, the portion of the pod rod close to the scroll 3 unfolds first, disrupting the stable unfolding order of the pod rod and causing unfolding failure. See the schematic diagram of unfolding failure. Figure 7 .

[0054] The materials of the pod stem half sheet 1 and the arc sheet 4 have shape memory properties. The smart polymer composite material is a new type of smart material made of smart polymers and their composite materials, wherein the smart polymer includes shape memory resins such as epoxy and cyanate ester, which can actively deform and return to a preset initial shape and maintain high stiffness under external stimuli such as heat, light or magnetism, and has shape memory function, and the composite material is made of raw materials including carbon fiber, glass fiber or aramid fiber, etc., which can increase the driving force of deformation when the smart polymer is deformed, and ensure the stability of the structure made of the smart composite material, and enhance its fracture toughness.

[0055] In addition to the bean pod stem half piece 1 being made of the smart polymer composite material, according to actual needs, part of the half piece, such as the middle arc segment 13 or the middle arc segment and the concave arc segments 12 on both sides, can be made of the smart polymer composite material, and the other parts can be made of the fiber reinforced resin-based composite material.

[0056] The bean pod stem half piece 1 is prepared by conventional vacuum hot pressing of composite materials, or by using additive manufacturing technology.

[0057] The heating film pasted in the embodiment of the present invention is to achieve thermal excitation of the material. In addition, magnetic excitation 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 external electric heating film, etc. When magnetic excitation is used, ferromagnetic materials such as iron oxide particles can be filled in the smart polymer composite material. When electrical excitation is used, single-walled, multi-walled carbon nanotubes, graphene, carbon black, carbon nanopaper, carbon nanofibers or mixed particles can be doped in the smart polymer composite material; if a combined drive method is adopted, the particles doped in the system of the smart composite material should be a combination of two or more of the above.

[0058] The present invention can also replace the cross section of the pod rod with a C-shaped, circular, concave hexagonal, corrugated plate, elliptical, rounded diamond, hexagonal honeycomb, herringbone and other cross sections, such as Fig.11 shown.

[0059] The stable deployment control method proposed in the present invention can control the deployment time and deployment speed by adjusting the glass transition temperature of the material and the heating power of the heating film, and combining the cross-sectional size and thickness of the pod rod structure. The deployment time can reach the order of minutes, while the traditional elastic deployment method usually has a deployment time of the order of seconds, which will bring great impact and poor deployment stability.

[0060] Compared with the prior art, the present invention takes into account the engineering problems that are likely to occur during actual use. When the end of the elastic pod rod is loaded with a load, i.e., the reel 3 is unfolded, the disorderly unfolded pod rod is prone to the following phenomenon under the gravity of the reel, i.e., the load is placed on the pod rod, and the restoring force of the pod rod is insufficient to overcome the gravity of the reel to lift the reel, and is also insufficient to drag the reel to move in the unfolding direction, resulting in incomplete unfolding of the pod rod. Figure 7 shown.

[0061] Similarly, in Comparative Examples 1 and 2, since the heating film is long, when the last section of the heating film is heated, the entire section of the bean pod stem is heated, causing the bean pod stem near the reel to stretch in advance, which is prone to Figure 7 Comparative Examples 3 and 4 can solve this problem, but in practical applications, the energy provided by the satellite to the spacecraft is certain. When the power supply line of the spacecraft is limited and the power supply voltage is determined, the number of heating films cannot be increased infinitely and the size of the heating films cannot be changed at will. Therefore, Comparative Examples 3 and 4 in the present invention are no longer applicable.

[0062] Specifically, when using large smart composite-based pod poles, in order for deployment to be successful, it is important to avoid Figure 7 , and because the power supply voltage is consistent, in order for each heating film to reach the glass transition temperature of the smart composite material, it is necessary to stick multiple heating films of approximately equal length on the pod rod to achieve stable deployment of the pod rod, such as Comparative Examples 3 and 4. However, due to the limitation that the power supply lines on the spacecraft cannot be increased indefinitely, it is impossible to increase the number of heating films. In addition, when the power supply voltage is consistent, if the deployment success rate is increased by increasing the length of heating film two 22, heating film three 23, and heating film four 24 and reducing the length of heating film one 21, the temperature of heating film two 22, heating film three 23, and heating film four 24 will be low, and the glass transition temperature of the smart composite material will not be reached. The solution proposed in the present invention can solve the above two problems. Without increasing the number of heating films and changing the length of the heating films, the deployment process of the pod rod corresponding to the section of heating film one 21 is changed to ensure the successful deployment of the pod rod. The scheme of the present invention further improves the controllability of the deployment, and avoids the situation where the portion of the pod rod close to the reel 3 is deployed first when the heating film is too long, thereby disrupting the stable deployment sequence of the pod rod and bringing the risk of deployment failure.

[0063] The solution proposed by the present invention does not require additional power supply lines, but only requires the additional bonding of a high glass transition temperature intelligent polymer composite material on the pod rod. According to the size of the reel, test requirements such as the unfolding time, etc., and test phenomena, the length of the arc piece 4 near the reel and the glass transition temperature of the material can be flexibly adjusted to meet the requirements of spacecraft use. After the arc piece 4 is bonded, it is ensured that the end reel 3 finally rolls and unfolds stably to meet the requirements. Under the control of the present invention, no pod rod will appear during the unfolding process. Figure 7 The test phenomenon of the unfolding failure shown is that the end load reel 3 is placed on the pod rod, so that the pod rod can be unfolded stably, and the unfolding process shows Figure 8 The unfolding phenomenon shown in the figure, in this case, the force arm when lifting the reel during the unfolding of the pod rod is small, and the required restoring force of the pod rod is smaller, and the reel can be lifted to complete the unfolding. Or the reel can be dragged in the unfolding direction to complete the unfolding. The state of the pod rod before unfolding is shown in the figure Fig. 9 .

Claims

1. A stable deployment control method based on a smart composite material pod pole, characterized in that: The method is: Two heating films 1 and 2 are sequentially pasted on the half piece of bean pod stem, and a reel is arranged to realize the extrusion and winding of the bean pod stem by the reel; Pasting a circular arc sheet on the first heating film, wherein the glass transition temperature of the circular arc sheet is higher than the glass transition temperature of the bean pod stem half sheet; The folding process of the present invention is specifically as follows: when unfolding, the heating film 2 is energized first, and after the bean pod rod segment with the heating film 2 is unfolded, the heating film 1 is energized; after the heating film 1 is energized, the part of the heating film where the arc piece is not pasted first reaches the glass transition temperature of the material, and is heated and unfolded under the drive of the shape memory function, while the part where the arc piece is pasted has a higher glass transition temperature, and continues to be heated to achieve stable unfolding.

2. The stable deployment control method based on the intelligent composite material pod rod according to claim 1 is characterized in that: The materials of the bean pod rod half piece and the arc piece both have shape memory properties.

3. The stable deployment control method based on the intelligent composite material pod rod according to claim 2 is characterized in that: The material of the bean pod stem half piece and the arc piece is a smart polymer or a composite material thereof; the smart polymer includes epoxy resin and cyanate resin; the composite material is made of raw materials including carbon fiber, glass fiber or aramid fiber.

4. The stable deployment control method based on the intelligent composite material pod rod according to claim 1 is characterized in that: The bean pod stem half piece is prepared by a conventional vacuum hot pressing method or by using an additive manufacturing technology.

5. The stable deployment control method based on the intelligent composite material pod rod according to claim 1 is characterized in that: Other excitation methods are used: when thermal excitation is used, the heating element is an embedded resistance wire, an embedded electric heating film or an external electric heating film; when magnetic excitation is used, ferromagnetic material is filled in the smart polymer composite material; when electrical excitation is used, single-walled, multi-walled carbon nanotubes, graphene, carbon black, carbon nanopaper, carbon nanofibers or mixed particles are doped in the smart polymer composite material; if a combined drive method is used, the particles doped in the smart composite material system should be a combination of two or more of the above.

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

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