Space camera flexible light shield capable of realizing on-orbit long-amplitude section-by-section self-unfolding

Abstract

The invention relates to a space camera flexible light shield capable of being automatically unfolded section by section in an on-orbit long-amplitude mode, and belongs to the technical field of space camera light shield design. The flexible light shield of the space camera sequentially comprises a top flange, a light shielding skin and a bottom flange from top to bottom, a locking rope and a hot working cutter are arranged on the bottom flange; an extension arm is arranged in the shading skin; the top flange is fixed to the top end of the extending arm and connected with the shading skin. According to the space camera flexible light shield capable of on-orbit long-breadth section-by-section self-unfolding, the unfolding mechanism can be passively unfolded by means of elastic strain energy stored by the material, the mass is light, the mechanism is simple, and the rigidity is high. In addition, the mechanism can reach dozens of meters after being completely unfolded, space long-range unfolding can be achieved, the compression ratio is high, the launching space is effectively utilized, the launching cost is reduced, and the mechanism has practical value.

Description

Technical Field

[0001] The present invention relates to the technical field of the design of space camera light shields, and particularly relates to a flexible space camera light shield that can be longitudinally and sectionally self-unfolded in orbit. Background Art

[0002] The design of the optical system of a space remote sensing camera needs to consider the influence of stray light on the optical system. Existing solutions include:

[0003] 1) Technical measures are taken on the inner surface of the optical system light shield to reduce the internal reflectivity, and the stray light energy is attenuated or absorbed by directly reducing, multiple reflecting, or absorbing the incident light outside the field of view, etc., so as to achieve the purpose of attenuating the stray light energy. For example, a stop ring is arranged on the inner surface of the optical system and a multi-stage light shield is designed;

[0004] 2) The purpose of suppressing stray light is achieved by lengthening the light shield. Existing lengthening light shield technologies generally adopt deployable light shields. Due to the special space environment, the light shield needs to be in a retracted state during launch to save space and be deployed after entering the predetermined orbit to achieve the effect of blocking non-imaging light sources. Therefore, it must have a light weight and high reliability.

[0005] Existing deployable light shield technologies mainly include spring deployment, mechanism deployment, and inflatable deployment. The spring-deployed light shield relies on the preset spring elasticity and automatically unfolds after releasing the locking device. This method is simple and reliable, but it requires sufficient deployment force in the space environment. And its deployment accuracy is limited, and it is difficult to accurately control the deployment angle and position. Especially in a vacuum environment, too fast spring release may cause it to exceed the designed position during deployment.

[0006] The mechanism-deployed light shield generally uses mechanical hinges as deployment units and uses motors to provide driving force to control the deployment. Such mechanisms have a good technical foundation after years of development, but such mechanisms have more deployment units, a lower compression ratio, and a complex structure, and require an external driving force for deployment, with a large weight.

[0007] The inflatable-deployed light shield uses low-density gas (such as helium) or shape memory materials to deploy the light shield by methods such as inflation or heating. After the inflatable-deployed light shield is deployed, it usually adopts the rigidification technology of materials or structures, that is, the structure self-rigidifies to make it have a certain stiffness. The inflatable-deployed light shield has a light structure and is suitable for the design of large-area light shields, but its deployment accuracy is low, and its durability is poor, and there is a risk of gas leakage. It requires additional gas storage devices and complex release control devices, increasing the system design complexity and weight. Summary of the Invention

[0008] The present invention aims to solve the technical problems in the prior art that the structural mass of the mechanical unfolding light-shielding cover is large and the mechanism is complex, and provides a flexible light-shielding cover for a space camera that can be unfolded section by section in a long length in orbit.

[0009] To solve the above technical problems, the technical solution of the present invention is specifically as follows:

[0010] A flexible light-shielding cover for a space camera that can be unfolded section by section in a long length in orbit includes, from top to bottom: a top flange, a light-shielding skin, and a bottom flange; a locking rope and a pyrotechnic cutter are provided on the bottom flange; a stretching arm is provided inside the light-shielding skin;

[0011] The top flange is fixed to the top end of the stretching arm, and the light-shielding skin is connected to the top flange;

[0012] Both the top flange and the bottom flange are circular rings, with convex platforms provided circumferentially, and grooves are provided on the convex platforms;

[0013] The pyrotechnic cutter is installed on the convex platform of the bottom flange, and a rope-passing hole is provided thereon; the locking rope passes through the rope-passing hole, and both ends are respectively fixed in the convex platform grooves of the top flange and the bottom flange, and prestress is applied to fix the stretching arm in the retracted state on the bottom flange;

[0014] The stretching arm includes: three longitudinal rods, multiple articulated triangular cross frames, and multiple diagonal stiffening cables; each articulated triangular cross frame includes: three titanium-nickel alloy cross bars, three transfer hinges, and three fixed hinges; the titanium-nickel alloy cross bars are inserted into the mounting holes of adjacent two transfer hinges, and the transfer hinges and the fixed hinges are connected at the rotation center; each longitudinal rod respectively passes through the through holes of multiple fixed hinges arranged on the same straight line in the vertical direction; the diagonal stiffening cables pass through the through holes of the transfer hinges, and are obliquely tensioned and fixed between the articulated triangular cross frame sections in the loading order of left pressing right, and prestress is applied to improve the shear resistance and torsional stiffness of the stretching arm;

[0015] During the overall assembly of the camera, the bottom flange is installed at the position of the camera lens;

[0016] When the satellite is in orbit, the pyrotechnic cutter detonates to cut off the locking rope, and the stretching arm drives the light-shielding skin to unfold section by section to form a light-shielding cover.

[0017] In the above technical solution, the diagonal stiffening cable is made of multiple strands of wire ropes.

[0018] In the above technical solution, the material of the longitudinal rod is titanium-nickel shape memory alloy.

[0019] In the above technical solution, the multiple articulated triangular cross frames are fixed at a certain pitch.

[0020] In the above technical solution, the number of the articulated triangular cross frames is 3.

[0021] In the above technical solution, the number of diagonal stiffening cables is six.

[0022] The present invention has the following beneficial effects:

[0023] The flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention has a deployable mechanism that relies on the elastic strain energy stored in the material itself for passive deployment, with a relatively light mass, a simple mechanism, and a relatively high stiffness. In addition, after the sunshade mechanism is fully deployed, it can reach dozens of meters, enabling long-length space deployment, having a high compression ratio, effectively utilizing the launch space, reducing the launch cost, and having practical value. Description of the Drawings

[0024] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0025] Figure 1 It is a schematic structural view of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0026] Figure 2 It is a schematic structural view of the extension arm of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0027] Figure 3 It is a schematic structural view of the articulated triangular cross-frame in the extension arm of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0028] Figure 4 It is a deformation schematic view of a section of the extension arm of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0029] Figure 5 It is a schematic view of the deployment mode of the extension arm of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0030] Figure 6 It is a schematic view of the simulation (upper) and experimental process (lower) of the deployment process of the extension arm of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0031] Figure 7 It is a schematic structural view of the super-large-aperture sunshade formed after the synchronous deployment of the extension arms of the flexible sunshade of the space camera capable of on-orbit long-length and section-by-section self-unfolding of the present invention.

[0032] The reference numerals in the drawings are denoted as:

[0033] 1 - Top flange; 2 - Light-shielding skin; 3 - Locking rope; 4 - Pyrotechnic cutter; 5 - Bottom flange; 6 - Extension arm; 7 - Longitudinal rod; 8 - Articulated triangular cross-frame; 9 - Diagonal stiffening cable; 10 - Titanium-nickel alloy cross-bar; 11 - Adapter hinge; 12 - Fixed hinge. Detailed implementation mode

[0034] The inventive concept of the present invention is as follows:

[0035] The flexible light-shielding cover of the space camera that can be self-unfolded in a long amplitude and section by section in orbit of the present invention is a flexible light-shielding cover of the space camera that can be self-unfolded in orbit with a high compression ratio and a long unfolding distance. It does not require a motor to provide driving force and can rely on the elastic strain energy stored in the material itself to be unfolded passively in orbit. The structure is simple and the mass is relatively light.

[0036] The flexible light-shielding cover of the space camera that can be self-unfolded in a long amplitude and section by section in orbit of the present invention can reach dozens of meters after being fully unfolded, has a high compression ratio, makes more effective use of the launch space, has a high unfolding accuracy, and has high reliability and applicability.

[0037] The present invention will be described in detail below with reference to the accompanying drawings.

[0038] As Figure 1 shown, the flexible light-shielding cover of the space camera that can be self-unfolded in a long amplitude and section by section in orbit of the present invention includes: a top flange 1, a light-shielding skin 2, a locking rope 3, a pyrotechnic cutter 4, a bottom flange 5 and an extension arm 6.

[0039] The top flange 1 is fixed to the top end of the extension arm 6. The light-shielding skin 2 is connected to the top flange 1 by screws. Both the top flange 1 and the bottom flange 5 are circular rings, with circumferential bosses provided with grooves. The pyrotechnic cutter 4 is installed on the boss of the bottom flange 5 and is provided with a rope-passing hole. The locking rope 3 passes through the rope-passing hole and its two ends are respectively fixed in the groove of the boss of the top flange 1 and the bottom flange 5, and prestress is applied to fix the extension arm 6 in the retracted state on the bottom flange 5. When assembling the camera, the bottom flange 5 is installed at the position of the camera lens. When the satellite is in orbit, the pyrotechnic cutter 4 detonates to cut off the locking rope 3, and the extension arm 6 drives the light-shielding skin 2 to unfold section by section to form a light-shielding cover.

[0040] As Figure 2 shown, in the flexible light-shielding cover of the space camera that can be self-unfolded in a long amplitude and section by section in orbit of the present invention, there is an extension arm 6 that can be self-unfolded section by section, which mainly includes: three longitudinal rods 7, multiple articulated triangular cross-frames 8 and multiple diagonal stiffening cables 9.

[0041] As Figure 3As shown, each section of the articulated triangular cross frame 8 is composed of three titanium-nickel alloy cross bars 10, three transfer hinges 11 and three fixed hinges 12, providing lateral support for the longitudinal bars 7; the titanium-nickel alloy cross bars 10 are inserted into the mounting holes of two adjacent transfer hinges 11, and the transfer hinges 11 and the fixed hinges 12 are connected by screws at the rotation center. The length of the titanium-nickel alloy cross bars 10 determines the winding radius of the extension arm 6; there are three longitudinal bars 7 extending from the top flange 1 to the bottom flange 5, made of titanium-nickel shape memory alloy, which pass through the through holes of the fixed hinges 12 and are fixed by screws. Several sections of the articulated triangular cross frames 8 are fixed at a certain pitch, and the number of articulated triangular cross frames 8 is 3. Figure 4 As shown, the length of the longitudinal rod 7 is That is, the fully extended length of the extension arm 6, and the height of the extension arm 6 during the extension process ,in: is the rotation angle between two adjacent articulated triangular transverse frames 8, is the coiling radius (i.e. the circumscribed circle radius); the diagonal stiffening cables 9 are made of multiple strands of steel wire ropes, a total of 6, passing through the through hole of the transfer hinge 11, strictly implementing the loading sequence of left-pressing-right, and are fixed obliquely between the hinged triangular cross frames 8 to apply prestress , which can greatly improve the shear and torsional rigidity of the extension arm 6.

[0042] The flexible light shield for a space camera that can be self-deployed section by section on-orbit in the present invention has two states: unfolded and folded. It can be formed into a folded body in a curled form during the launch phase of the spacecraft, and unfolded to a predetermined configuration after entering orbit. The extension arm 6 is made of a superelastic shape memory alloy material, and the longitudinal rod 7 is coiled circumferentially to store strain energy when the extension arm 6 is folded, and the strain energy is converted into axial kinetic energy when it is unfolded. The articulated triangular cross frame 8 is composed of three transfer hinges 11, three fixed hinges 12 and three titanium-nickel alloy cross bars 10, which are orthogonal to the unfolding direction, and are used to limit the coiling radius of the extension arm 6 and increase the lateral stiffness.

[0043] like Figure 4 and 5 As shown, the extension arm 6 is a passive deployment mechanism, and its deployment mode is determined by the stiffness ratio of the longitudinal rod 7 and the titanium-nickel alloy cross rod 10 ( Figure 5 The ratio of longitudinal and transverse rod stiffness) and pitch and coil radius For the circular cross-section rods of the longitudinal rod 7 and the titanium-nickel alloy cross rod 10, the bending stiffness , is the radius of the longitudinal rod 7 or the titanium-nickel alloy crossbar 10, Indicates the elastic modulus of the material. When the critical state longitudinal rod 7 exerts pressure on the next section of the titanium-nickel alloy cross bar 10 Greater than the tension of the titanium-nickel alloy crossbar 10 itself When, that is , where: is the radial component of the tension of the diagonal stiffening cable 9, is an elliptic integral, is the length of the titanium-nickel alloy cross bar 10, is the flexural rigidity. When the parameter point falls above the curve, the extension arm 6 can be unfolded section by section, and the unfolding process is stable.

[0044] As Figure 6 shown, the simulation and experiment show that after the locking of the extension arm 6 is released, relying on the strain energy stored in the elastic material itself, the longitudinal rod 7 that is coiled and retracted layer by layer starts elastic recovery from the root, drives the overall structure to be unfolded section by section, and drives the light-shielding skin 2 to be unfolded synchronously to form a light-shielding cover structure. The flexible light-shielding cover of the space camera that can be unfolded in orbit with a long amplitude and section by section of the present invention is practical and effective.

[0045] As Figure 7 shown, controlling the synchronous unfolding of multiple extension arms 6 can form a light-shielding cover with an ultra-large aperture. Controlling the simultaneous detonation of the pyrotechnic cutters 4 to cut off the locking ropes 3 of multiple extension arms 6 enables multiple extension arms 6 to be unfolded synchronously, and at the same time drives the light-shielding skin 2 connected between adjacent extension arms 6 to be unfolded synchronously to form a light-shielding cover with an ultra-large aperture.

[0046] The flexible light-shielding cover of the space camera that can be unfolded in orbit with a long amplitude and section by section of the present invention, its unfolding mechanism relies on the elastic strain energy stored in the material itself for passive unfolding, with a light weight, a simple structure, and a high rigidity. In addition, after the light-shielding cover mechanism is fully unfolded, it can reach dozens of meters, can realize long-amplitude unfolding in space, and has a high compression ratio, effectively utilizes the launch space, reduces the launch cost, and has practical value.

[0047] Obviously, the above embodiments are only examples given for clear illustration, and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A flexible light shield for a space camera that can be unfolded section by section in a long stroke in orbit, characterized in that, From top to bottom, it successively includes: a top flange (1), a light-shielding skin (2), and a bottom flange (5); a locking rope (3) and a pyrotechnic cutter (4) are provided on the bottom flange (5); an extension arm (6) is provided inside the light-shielding skin (2). The top flange (1) is fixed to the top end of the extension arm (6), and the light-shielding skin (2) is connected to the top flange (1). Both the top flange (1) and the bottom flange (5) are circular rings, with bosses provided circumferentially, and grooves provided on the bosses. The pyrotechnic cutter (4) is installed on the boss of the bottom flange (5), and a rope-passing hole is provided thereon; the locking rope (3) passes through the rope-passing hole, and both ends are respectively fixed in the boss grooves of the top flange (1) and the bottom flange (5), and prestress is applied to fix the extension arm (6) in the retracted state on the bottom flange (5). The extension arm (6) includes: three longitudinal rods (7), multiple articulated triangular cross frames (8), and multiple diagonal stiffening cables (9); each articulated triangular cross frame (8) includes: three titanium-nickel alloy cross bars (10), three transfer hinges (11), and three fixed hinges (12); the titanium-nickel alloy cross bars (10) are inserted into the mounting holes of two adjacent transfer hinges (11), and the transfer hinges (11) and the fixed hinges (12) are connected at the rotation center; each longitudinal rod (7) respectively passes through the through holes of multiple fixed hinges (12) arranged on the same straight line in the vertical direction; the diagonal stiffening cables (9) pass through the through holes of the transfer hinges (11), and are obliquely tension-fixed between the sections of the articulated triangular cross frames (8) in the loading order of left pressing right, and prestress is applied to improve the shear resistance and torsional stiffness of the extension arm (6). When performing the overall assembly of the camera, the bottom flange (5) is installed at the position of the camera lens. After the satellite is in orbit, the pyrotechnic cutter (4) detonates to cut off the locking rope (3), and the extension arm (6) drives the light-shielding skin (2) to unfold section by section to form a light-shielding cover.

2. The flexible light shield of the space camera capable of on-orbit long-stroke and section-by-section self-unfolding according to claim 1, wherein, The diagonal stiffening cables (9) are made of multiple strands of wire ropes.

3. The flexible light shield of the space camera capable of on-orbit long-stroke and section-by-section self-unfolding according to claim 1, wherein The material of the longitudinal rods (7) is titanium-nickel shape memory alloy.

4. The flexible light shield of the space camera capable of on-orbit long-stroke and section-by-section self-unfolding according to claim 1, characterized in that, The multiple articulated triangular cross frames (8) are fixed at a certain pitch.

5. The flexible light shield of the space camera capable of long-stroke and section-by-section self-unfolding in orbit according to claim 1, characterized in that, The number of the articulated triangular cross frames (8) is 3.

6. The flexible sunshade for a space camera that can be self-expanded section by section on track according to claim 1, characterized in that: The number of the diagonal stiffening cables (9) is 6.

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