Radially and axially deployable truss mechanism and deployment method for flexible space habitats

Abstract

The application discloses a radial and axial deployable truss mechanism applied to a flexible space cabin and a deployment method. The truss mechanism comprises an adapter frame and a synchronous bidirectional deployment truss mechanism body, the body comprising a plurality of axial telescopic mechanisms uniformly distributed in the circumferential direction, radial telescopic mechanisms arranged at two ends of the axial telescopic mechanisms, a truss base supporting the radial telescopic mechanisms and a hexagonal framework telescopic mechanism connecting adjacent axial telescopic mechanisms. The two ends of each axial telescopic mechanism are connected with corresponding radial telescopic mechanisms through connecting bent rods, forming a lantern-shaped space framework, and the synchronous deployment is driven by inflation and expansion of a flexible air bag, and the bidirectional mechanical limiting is realized through cooperation of a limiting sleeve and a rod shaft shoulder. The deployment method is driven by inflation of the air bag after the pin extractor is unlocked, and each telescopic mechanism is synchronously stretched to the position. The application realizes synchronous bidirectional deployment in the radial and axial directions, has low energy consumption, high rigidity, and reserves a cavity for preloading of equipment in the contracted state.

Description

Technical Field

[0001] This invention relates to the design technology of internal support truss structure for flexible space capsules, specifically to a radially and axially deployable truss mechanism and deployment method for flexible space capsules. Background Technology

[0002] With the continued deepening of deep space exploration activities, conducting cutting-edge scientific experiments and resource development in the extreme space environment has become a key strategic direction for spacefaring nations, making the development of ultra-large, scalable, and multifunctional space platforms increasingly urgent. Traditional rigid sealed modules are limited by the size of the launch vehicle fairing, severely restricting on-orbit usable space and incurring high costs per launch, making it difficult to support the large-scale living and working space requirements of future missions such as lunar bases and manned Mars exploration. Flexible inflatable space capsules, with advantages such as "small-volume launch, large on-orbit space, and low-cost operation," are considered one of the effective technological approaches to overcome these bottlenecks.

[0003] The design challenge of flexible inflatable spacecraft lies not in its "deployability," but in finding a feasible and delicate balance within a specific and contradictory engineering scenario. This contradictory scenario includes, for example: 1) the flexible material properties of the inflatable deployment capsule cause drastic changes in structural modes during inflation, making it difficult for the attitude control system to establish a stable model, and significantly increasing the risk of coupled vibration between the capsule and the spacecraft; 2) after deployment, stiffness still relies on internal air pressure, making it prone to continuous swaying under maneuvering or impact disturbances, affecting the attitude stability of other connected modules. Therefore, it is urgent to install a rigid truss structure inside the capsule to provide stable mechanical boundaries. Existing technologies improve stiffness by adding rigid support structures inside the capsule, for example: first, using shape memory polymer composite materials to create a foldable skeleton, which is deployed by heating, but the heating process is energy-intensive and temperature field control is complex; or second, setting a retractable central cylindrical shell structure, but this can only extend and retract axially, making it difficult to achieve synchronous expansion in radial space; third... Some systems use a motor-driven lead screw in conjunction with multiple linkage mechanisms to achieve deployment. The mechanical structure is fixed, making it impossible to adjust the deployment size according to the mission. Furthermore, the transmission components are numerous and heavy, and the retracted state significantly encroaches on the internal space, which is not conducive to the pre-installation of experimental equipment and payloads during the launch phase. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a radially and axially deployable truss mechanism and deployment method for flexible space capsules. The first objective is to solve the problem of insufficient rigidity in flexible inflatable capsules, leading to structural swaying and high risk of coupled vibration during inflation and disturbance. The second objective is to address the problem that existing rigid support structures cannot simultaneously achieve radial and axial bidirectional deployment, resulting in low space expansion efficiency. The third objective is to solve the problems of high energy consumption, complex control, fixed mechanical structure, heavy weight, and encroachment on internal space during launch associated with existing drive methods.

[0005] To solve its technical problems, the present invention proposes the following technical solutions:

[0006] A radially and axially deployable truss mechanism for a flexible space capsule, comprising: a transition frame (5) and a truss mechanism body, wherein one side of the transition frame (5) is connected to the rigid section (3) of the flexible space capsule, and the other side is connected to the truss mechanism body, characterized in that:

[0007] The main body of the truss mechanism is a synchronous bidirectional unfolding truss mechanism; the synchronous bidirectional unfolding truss mechanism includes: multiple axial telescopic mechanisms (9) evenly distributed along the circumference and extending vertically, radial telescopic mechanisms (8) arranged at both ends of the multiple axial telescopic mechanisms (9), truss base (6) for supporting the radial telescopic mechanisms (8), and hexagonal skeleton telescopic mechanism (10); the axial unfolding of the truss mechanism is achieved through the axial telescopic mechanism (9); the radial unfolding of the truss mechanism is achieved through the radial telescopic mechanism (8); the hexagonal skeleton telescopic mechanism (10) is used to connect the middle rods of adjacent axial telescopic mechanisms (9) to form circumferential constraints; when unfolded, it extends outward synchronously with the axial telescopic mechanism (9), connecting each independent axial telescopic mechanism into an integral space frame, serving as a lateral tie between multiple axial telescopic mechanisms (9), so that the entire skeleton changes from "multiple independent columns" to "integrated space frame";

[0008] The radial telescopic mechanism (8) is composed of multiple first radial telescopic mechanisms (8-1) and multiple second radial telescopic mechanisms (8-2); the multiple first radial telescopic mechanisms (8-1) are arranged at one end of the multiple axial telescopic mechanisms (9), and the multiple second radial telescopic mechanisms (8-2) are arranged at the other end of the multiple axial telescopic mechanisms (9);

[0009] The truss base (6) includes a first truss base (6-1) for supporting a plurality of first radial telescopic mechanisms (8-1) and a second truss base (6-2) for supporting a plurality of second radial telescopic mechanisms (8-2); the first truss base (6-1) and the second truss base (6-2) are arranged opposite each other along the axial direction of the axial telescopic mechanism (9), the first truss base (6-1) is located on the outer end face of the first radial telescopic mechanism (8-1), and the second truss base (6-2) is located on the outer end face of the second radial telescopic mechanism (8-2).

[0010] Each of the axial telescopic mechanisms (9) is disposed between the first truss base (6-1) and the second truss base (6-2); and one end of each of the axial telescopic mechanisms (9) is connected to the corresponding first radial telescopic mechanism (8-1) through the first connecting bent rod (22-1), and the other end is connected to the corresponding second radial telescopic mechanism (8-2) through the second connecting bent rod (22-2). The multiple axial telescopic mechanisms (9) are arranged circumferentially to form the longitudinal ribs of the lantern frame;

[0011] The inner end of the radial telescopic mechanism (8) is connected to the truss base (6), and the outer end extends radially outward and is connected to the corresponding end of the corresponding axial telescopic mechanism (9).

[0012] The axial telescopic mechanism (9) and the radial telescopic mechanism (8) are synchronously deployed by the inflation and expansion of the flexible airbag. The main body of the truss mechanism is in the shape of a folded lantern skeleton in the contracted state and in the shape of an open lantern skeleton in the deployed state.

[0013] Further, the inner end of the radial telescopic mechanism (8) is connected to the truss base (6) specifically as follows: the radial telescopic mechanism (8) consists of the following components from the inner diameter to the outer diameter: a first base telescopic rod fixing frame (11), a first limiting sleeve (13), an electromagnetic puller (17), a radial telescopic outer rod (14), a second limiting sleeve (18), a radial telescopic inner rod (16), a second base telescopic rod fixing frame (20), and a second telescopic rod connector (19); the first base telescopic rod fixing frame (11) and the second base telescopic rod fixing frame (20) are fixed to the truss base (6) by bolts and nuts, and the radial telescopic outer rod (14) is fixed at the same time; a first limiting sleeve (13) and a second limiting sleeve (18) are threaded to each end of the radial telescopic outer rod (14), and after the sleeve is screwed in, its end face forms a limiting step in the inner cavity of the outer rod.

[0014] Furthermore, the radial telescopic inner rod (16) is a stepped round rod, with its large diameter section matching the inner diameter of the radial telescopic outer rod (14) and its small diameter section matching the inner diameter of the second limiting sleeve (18). When the radial telescopic inner rod (16) slides between the two sleeves, its shoulder end face abuts against the end faces of the front and rear sleeves respectively, thereby limiting the two extreme positions of contraction and extension and realizing bidirectional mechanical limiting. A slot (15) is opened on the large diameter section of the radial telescopic inner rod (16), and an electromagnetic pin puller (17) is installed in the slot (15). A corresponding annular groove (21) is provided on the inner wall of the radial telescopic outer rod (14). When the main body of the truss mechanism is in the retracted state, the head of the electromagnetic pin puller (17) extends out and gets into the annular groove (21), locking the radial telescopic inner rod (16) in the retracted position. When the main body of the truss mechanism needs to be unfolded, the electromagnetic pin puller (17) is energized to unlock, the head of the pin comes out of the annular groove (21), and the radial telescopic inner rod (16) can slide freely axially within the radial telescopic outer rod (14).

[0015] Furthermore, the axial telescopic mechanism (9) is fitted with three layers of rods in a radial direction from the outside to the inside: the outer axial rod (32), the second axial rod (33), and the third axial rod (35). Similar to the radial telescopic mechanism (8), the axial telescopic mechanism (9) also uses a limiting sleeve to achieve bidirectional mechanical limiting.

[0016] Furthermore, an axial outer layer rod (32) is fitted with an axial outer layer rod bottom sleeve (31) at one end near the rigid section (3) of the space capsule. The axial outer layer rod bottom sleeve (31) serves as a bottom limit for the axial second layer rod (33) on the one hand, and as a connection interface on the other hand, it is fixed to the first connecting bent rod (22-2) near the rigid section (3) of the space capsule by means of threads.

[0017] Furthermore, the axial second-layer rod (33) is a composite structure, consisting of two threaded parts with different diameters: the part with a larger thread diameter is adapted to the inner diameter of the axial outer layer rod (32), and the part with a smaller thread diameter is a tubular round rod whose outer diameter is adapted to the inner diameter of the axial second-layer rod limiting sleeve (34); the larger diameter part has an annular step (37) machined at the end connected to the smaller diameter section, and the annular step (37) extends into the interior of the tubular round rod of the smaller diameter section to limit and abut against the bottom end face of the axial third-layer rod (35).

[0018] Furthermore, the axial triple-layer rod (35) is located inside the axial double-layer rod (33), and its bottom end face abuts against the annular step (37), thereby achieving bottom limiting. That is, when the axial triple-layer rod (35) is in the retracted state, the end face of its large diameter section falls exactly on the annular step (37), preventing it from coming off the bottom of the axial double-layer rod (33). When unfolded, the axial triple-layer rod (35) slides upward until its large diameter end face touches the end face of the axial triple-layer rod limiting sleeve_36, reaching the unfolding limit position. Through the above three-layer hierarchical stacking and limiting cooperation, the axial telescopic mechanism can achieve multi-stage axial stretching and unfolding, and after each stage extends to the position, its limit position is limited by the corresponding limiting sleeve.

[0019] Furthermore, the axial second-layer rod limiting sleeve (34) and the axial third-layer rod limiting sleeve (36) are evenly distributed with mounting holes at 120° intervals along the circumference. A hexagonal skeleton connector (41) is installed at each mounting hole by a threaded fixing pin (42) and two fixing nuts. There are a total of three hexagonal skeleton connectors on each limiting sleeve. Two inner adjacent connectors are used to connect the hexagonal skeleton telescopic mechanism (10), and the other outer connector is used to connect the inner fixing interface (43) of the flexible airbag.

[0020] Furthermore, each of the limiting sleeves is provided with three hexagonal skeleton connectors (41) that are 120° apart, wherein two adjacent hexagonal skeleton connectors (41) are used to connect the hexagonal skeleton telescopic mechanism (10), and the other hexagonal skeleton connector (41) is used to connect the inner wall of the flexible airbag.

[0021] A radial-axial deployment method for a flexible spacecraft, characterized by the following steps:

[0022] 1) All telescopic rods of the truss mechanism are in a fully retracted state: In the radial telescopic mechanism, the electromagnetic pin puller is energized and locked, the pin head extends and engages in the annular groove on the inner wall of the outer rod, locking the radial telescopic inner rod in the retracted position; in the axial telescopic mechanism, each layer of rods is stacked and retracted step by step, and each layer of limiting sleeves is in an initial non-contact state; the hexagonal frame telescopic mechanism is also in a retracted and locked state. Each limiting sleeve and the shoulder limiting surface of the stepped rod maintains a slight gap in the retracted state, ensuring that each rod can slide freely after unlocking. Check the tightness of each threaded fixing pin and connector to confirm there is no looseness.

[0023] 2) Orbital insertion and separation: After the rocket launches, it enters the predetermined orbit and the fairing is jettisoned; the onboard avionics system issues a separation command, the capsule separates from the rocket, and the control circuit inside the capsule receives the signal;

[0024] 3) Unlocking the pin pullers: After receiving the separation signal, the control circuit immediately outputs an unlocking command to each electromagnetic pin puller. The electromagnetic pin pullers are energized and actuate, the pin head exits from the annular groove on the inner wall of the outer rod, the radially telescopic inner rod is released from constraint, and the entire truss mechanism changes from a locked state to a freely movable state;

[0025] 4) Airbag Inflation and Truss Deployment: The control circuit drives the solenoid valve to open, and the high-pressure gas cylinder inflates the cabin. The gas is evenly released through pipelines to reduce disturbance to the cabin's attitude. As the flexible airbag gradually inflates, the inner wall of the airbag pulls the axial telescopic mechanisms and the hexagonal skeleton telescopic mechanism outward through the hexagonal skeleton connector. The specific deployment process is as follows: The hexagonal skeleton telescopic mechanism first extends radially under the action of the airbag inflation force; at the same time, the rods in each layer of the axial telescopic mechanism are pulled out step by step—the second axial rod slides out relative to the outer axial rod, and after it is in place, its second-layer limiting sleeve abuts against the bottom sleeve or limiting step of the outer axial rod, realizing the first level of limiting; the third axial rod continues to slide out relative to the second axial rod until its bottom end face abuts against the inner step of the large diameter section of the second axial rod, while its top touches the third-layer limiting sleeve, realizing the second level of bidirectional limiting. During this process, the six radial telescopic mechanisms on the base are simultaneously subjected to force and extend outward radially. After the stepped shoulders of each inner rod contact the end face of the corresponding limiting sleeve, they reach the extended limit position. After all the telescopic rods are fully extended, a complete hexagonal honeycomb support frame is formed. Advantages and effects of the present invention

[0026] 1. Significantly improves the structural stiffness and stability of the flexible space capsule. The present invention uses an axial telescopic mechanism (9), a radial telescopic mechanism (8), and a hexagonal frame telescopic mechanism (10) to form a complete hexagonal honeycomb spatial support frame. After each telescopic mechanism is deployed, it achieves bidirectional mechanical limiting through hard contact between the end face of the limiting sleeve and the shoulder of the rod. This solves the problem of insufficient stiffness of the flexible inflatable capsule, structural swaying during inflation and disturbance, and high risk of coupled vibration. It ensures that the deployed shape does not depend on the air pressure inside the capsule. Even if the capsule is depressurized or subjected to impact disturbance, the rigid frame can still provide a stable mechanical boundary for the capsule.

[0027] 2. Achieve synchronous bidirectional expansion in both radial and axial directions, significantly improving space expansion efficiency. This invention uses a connecting rod (22) to rigidly link the axial telescopic mechanism (9) and the radial telescopic mechanism (8), enabling them to expand synchronously driven by the inflation of the flexible airbag. This solves the problem that existing rigid support structures can only expand and contract along the axial direction and cannot achieve synchronous radial space expansion. It achieves space multiplication in both axial and radial dimensions, significantly improving the effective volume of the cabin.

[0028] 3. The energy consumption for deployment is extremely low, and the control is simple and reliable. This invention uses the electromagnetic pin puller (17) for instantaneous unlocking and the inflation force of the flexible airbag as the only driving force for deployment. After unlocking, it relies entirely on the airbag force to passively drive each telescopic mechanism to deploy synchronously. This solves the problems of high energy consumption, complex temperature control, and many and heavy components of the motor screw drive of shape memory polymer heating. The deployment process only requires milliwatt-level instantaneous electrical energy from the pin puller. The control logic is only power-on unlocking, without the need for complex force / position closed-loop control or precise temperature control.

[0029] 4. The retracted state does not encroach on the internal space, allowing for pre-installation of equipment. The telescopic mechanisms of this invention adopt a multi-layered rod design with sequentially stacked rods from the outside to the inside. Even in the fully retracted state, the interior still retains a cavity for pre-installation of equipment. This solves the problem that existing linkage mechanisms fill the internal space with transmission components when retracted, which is not conducive to the pre-installation of experimental equipment and payloads during the launch phase. This achieves efficient utilization of the space inside the launch vehicle fairing and reduces launch costs. Attached Figure Description

[0030] Figure 1 This is an illustration of the application effect of the flexible space capsule of the present invention;

[0031] Figure 2 This is a schematic diagram of the main body of the truss mechanism of the present invention;

[0032] Figure 3 This is a view of the main base assembly and radial telescopic mechanism of the truss mechanism of the present invention;

[0033] Figure 4 This is a schematic diagram of the axial telescopic mechanism of the main body of the truss mechanism of the present invention;

[0034] Figure 5 A schematic diagram of the bidirectional unfolding of the main body of the truss mechanism of the present invention;

[0035] Figure 6 A schematic diagram of the connection point of the hexagonal skeleton of the main body of the truss mechanism of the present invention;

[0036] Figure 7 Schematic diagram of the telescopic rod fixing bracket 2 of the main body base of the truss mechanism of the present invention;

[0037] Figure 8 Schematic diagram of the telescopic rod fixing bracket 1 of the main body base of the truss mechanism of the present invention;

[0038] Figure 9 A schematic diagram of the main body transition frame of the truss mechanism of the present invention.

[0039] In the diagram, 1: Flexible space capsule deployable truss; 2: Flexible space capsule airbag; 3: Flexible space capsule rigid section; 4: Satellite platform; 5: Adapter frame; 6: Truss base; 7: Through slot; 8: Radial telescopic mechanism; 9: Axial telescopic mechanism; 10: Hexagonal skeleton telescopic mechanism; 11: First base telescopic rod fixing frame; 12: First telescopic rod connector; 13: First limiting sleeve; 14: Radial telescopic outer rod; 15: Hole slot; 16: Radial telescopic inner rod; 17: Electromagnetic puller; 18: Second limiting sleeve; 19: Second telescopic rod connector; 20: Second base telescopic rod fixing frame; 21: Annular groove; 22: Connecting bent rod; 32: Axial outer rod; 33: Axial second rod; 34: Axial second rod limiting sleeve; 41: Hexagonal skeleton connector; 42: Threaded fixing pin; 43: Flexible airbag inner fixing interface; 51: Telescopic rod fixing baffle. Detailed Implementation Innovation of this invention

[0040] Innovation Point 1: Synchronous bidirectional expansion of the lantern-shaped spatial skeleton structure: The present invention forms a complete lantern-shaped spatial frame by coordinating the axial telescopic mechanism (9) and the radial telescopic mechanism (8), and the hexagonal skeleton telescopic mechanism (10) circumferentially connecting the adjacent axial telescopic mechanism rods, thereby realizing synchronous bidirectional expansion in both the radial and axial directions and solving the problem that the existing technology can only telescopic in one direction and has low spatial expansion efficiency.

[0041] Innovation Point 2: Completely passive airbag inflation and deployment method: In this invention, each telescopic mechanism is driven by the inflation and expansion of flexible airbags to deploy synchronously, without the need for active driving components such as motors and lead screws. The electromagnetic pin puller (17) is only used for unlocking. After unlocking, the entire deployment action is completed by the inflation force of the airbags. The energy consumption is extremely low, which solves the problems of high energy consumption, complex temperature field control, or many transmission components and heavy weight in the prior art.

[0042] Innovation Point 3: The nested rod design that retains the internal cavity in the retracted state: Each telescopic mechanism of this invention adopts a multi-level nested rod. In the retracted state, the main body of the truss mechanism is in the shape of a closed lantern skeleton, and the interior still retains a cavity for equipment pre-installation. This solves the problem that existing mechanical structures encroach on the internal space when retracted, which is not conducive to the pre-installation of equipment during the launch phase.

[0043] Innovation Point 4: Two-way mechanical limiting ensures rigidity after deployment: Each telescopic mechanism of this invention achieves two-way mechanical limiting at the two extreme positions of contraction and extension by abutting the end face of the limiting sleeve and the shoulder of the rod. After deployment, the skeleton shape is maintained by mechanical limiting. Even if the cabin is depressurized or impacted, the skeleton can provide a stable mechanical boundary, which solves the problem of insufficient rigidity and easy shaking of flexible cabins. Design principle of the invention

[0044] This invention addresses three core issues facing flexible inflatable space capsules, proposing solutions from three levels: mechanical structure, kinematic design, and propulsion strategy.

[0045] I. Design principle for addressing the problem of "insufficient stiffness and easy swaying of flexible cabin": The stiffness of the flexible airbag after deployment depends entirely on the internal air pressure. Once the air pressure fluctuates or is subjected to external impact, the structure will experience continuous low-frequency swaying, which cannot provide a stable mechanical boundary for the cabin. Solution principle: The present invention adopts a mechanical strategy of "rigid-flexible separation" - the flexible airbag only serves as the power source for deployment and the sealing skin, and does not bear the main load-bearing function; the shape maintenance and load transfer after deployment are completely completed by the rigid truss. Specifically, it is achieved through a three-level structure: the axial telescopic mechanism (9) serves as the longitudinal main load-bearing rib and bears the axial load; the radial telescopic mechanism (8) serves as the end radial support and transfers the load to the truss base (6); the hexagonal skeleton telescopic mechanism (10) serves as the middle circumferential stirrup and connects the rods of each axial telescopic mechanism to each other, so that each independent column is connected into an overall spatial grid. The three together constitute a complete hexagonal honeycomb spatial skeleton - this configuration has the highest in-plane stiffness and buckling resistance under the same weight. More importantly, after each telescopic mechanism is deployed, it is mechanically limited in both directions by the hard contact end face of the limiting sleeve and the shoulder of the rod. The deployed shape does not depend on air pressure. Even if the cabin is completely depressurized, the rigid frame can still provide a stable mechanical boundary, which solves the problem of insufficient stiffness of the flexible cabin from the root.

[0046] II. Design principle for addressing the problem of "inability to deploy in both directions simultaneously and low efficiency of space expansion": Existing structures such as central cylindrical shells can only extend and retract in one direction along the axial direction. The radial space is limited by the fairing envelope during launch and cannot be expanded after entering orbit, resulting in limited improvement in effective volume. This invention decomposes the space expansion into two mutually orthogonal motion dimensions, axial and radial, and achieves synchronous driving of the two through kinematic coupling: Axial dimension: The axial telescopic mechanism (9) adopts a three-stage stacked rod, which is pulled out step by step to achieve multi-stage amplification of the axial dimension; Radial dimension: The radial telescopic mechanism (8) is fixed on the truss base (6), with the inner end connected to the base and the outer end connected to the end of the axial telescopic mechanism (9) through the connecting bent rod (22), extending outward in the radial direction. The kinematic coupling between the two is reflected in the fact that the axial telescopic mechanism (9) and the radial telescopic mechanism (8) are rigidly connected by a connecting rod (22). When the radial telescopic mechanism (8) extends outward in the radial direction, it drives the axial telescopic mechanism (9) to translate outward in the radial direction at the same time through the connecting rod. When the axial telescopic mechanism (9) extends in the axial direction, it transmits the axial displacement to the radial telescopic mechanism through the connecting rod at the end. The radial telescopic mechanism drives the synchronous expansion of the axial telescopic mechanism, and the axial telescopic mechanism in turn drives the radial telescopic mechanism to move outward further. The two-dimensional motion promotes and amplifies each other, realizing a true synchronous bidirectional expansion. The spatial volume is multiplied in both the axial and radial dimensions.

[0047] III. Design Principles for Addressing the Issues of "High Energy Consumption, Complex Control, and Intrusion into Internal Space During Launch"

[0048] Shape memory polymers require continuous heating for operation, resulting in high energy consumption and complex temperature control. The motor screw mechanism requires continuous power supply and complex force / position control, with many components, heavy weight, and connecting rods filling the internal space when retracted. This invention decomposes the unfolding process into two stages: "unlocking" and "unfolding," each employing a distinctly different driving strategy: Unlocking stage: Only a momentary electrical energy needs to be applied to the electromagnetic pin puller (17), causing the pin head to exit from the annular groove (21), allowing each telescopic rod to transition from a locked to a freely movable state—the energy consumption in this stage is only a milliwatt-level instantaneous power consumption, and the control logic is a simple power-on unlocking, requiring no closed-loop feedback. Unfolding stage: Completely zero energy consumption—the flexible airbag itself inflates as the sole driving force, and the inner wall of the airbag pulls each telescopic mechanism outward synchronously through the hexagonal skeleton connector (41), without consuming any additional energy. Unlike shape memory polymers that require full-process heating or motor leadscrews that require full-process active drive, this invention combines "energy" and "driving force" into one, utilizing the inevitable inflation process of the cabin to complete the deployment without adding any extra energy requirements or control system complexity. Space utilization strategy: Each telescopic mechanism adopts a multi-level nested rod design from the outside in. In the retracted state, each layer of rods is nested within the same contour, with the middle area completely hollow, forming a complete cavity for equipment pre-assembly. Unlike linkage mechanisms where the rods intersect and fill the internal space in the retracted state, the nested rods occupy only the cross-sectional area of ​​the outermost rod, completely releasing the internal space and achieving efficient utilization of the launch space.

[0049] Based on the above principles, this invention designs a radially and axially deployable truss mechanism for flexible spacecraft, such as... Figure 1-9 As shown, the truss mechanism includes: a transition frame 5 and a truss mechanism body. The transition frame 5 is connected to the rigid section 3 of the flexible space capsule on one side and to the truss mechanism body on the other side. Its characteristics are:

[0050] The main body of the truss mechanism is a synchronously bidirectionally deployable truss mechanism. This synchronously bidirectionally deployable truss mechanism includes: multiple axial telescopic mechanisms 9 evenly distributed circumferentially and extending vertically; radial telescopic mechanisms 8 arranged at both ends of the multiple axial telescopic mechanisms 9; a truss base 6 for supporting the radial telescopic mechanisms 8; and a hexagonal skeleton telescopic mechanism 10. The axial deployment of the truss mechanism is achieved through the axial telescopic mechanisms 9; the radial deployment of the truss mechanism is achieved through the radial telescopic mechanisms 8. The hexagonal skeleton telescopic mechanism 10 is used to connect the intermediate bars of adjacent axial telescopic mechanisms 9, forming a circumferential constraint. During deployment, it extends outward synchronously with the axial telescopic mechanisms 9, connecting the various independent axial telescopic mechanisms into a whole space frame, serving as a lateral tie between multiple axial telescopic mechanisms 9, transforming the entire skeleton from "multiple independent columns" into a "whole spatial space frame."

[0051] The radial telescopic mechanism 8 consists of multiple first radial telescopic mechanisms 8-1 and multiple second radial telescopic mechanisms (8-2); the multiple first radial telescopic mechanisms 8-1 are arranged at one end of the multiple axial telescopic mechanisms 9, and the multiple second radial telescopic mechanisms 8-2 are arranged at the other end of the multiple axial telescopic mechanisms 9.

[0052] The truss base 6 includes a first truss base 6-1 for supporting a plurality of first radial telescopic mechanisms 8-1 and a second truss base 6-2 for supporting a plurality of second radial telescopic mechanisms 8-2. The first truss base 6-1 and the second truss base 6-2 are arranged opposite each other along the axial direction of the axial telescopic mechanism 9. The first truss base 6-1 is located on the outer end face of the first radial telescopic mechanism 8-1, and the second truss base 6-2 is located on the outer end face of the second radial telescopic mechanism 8-2.

[0053] Each of the axial telescopic mechanisms 9 is disposed between the first truss base 6-1 and the second truss base 6-2; and one end of each of the axial telescopic mechanisms 9 is connected to the corresponding first radial telescopic mechanism 8-1 through the first connecting bent rod 22-1, and the other end is connected to the corresponding second radial telescopic mechanism 8-2 through the second connecting bent rod 22-2. The plurality of axial telescopic mechanisms 9 are arranged circumferentially to form the longitudinal ribs of the lantern frame.

[0054] The inner end of the radial telescopic mechanism 8 is connected to the truss base 6, and the outer end extends radially outward and is connected to the corresponding end of the axial telescopic mechanism 9.

[0055] The axial telescopic mechanism 9 and the radial telescopic mechanism 8 are synchronously deployed by the inflation and expansion of the flexible airbag. The main body of the truss mechanism is in the shape of a folded lantern skeleton in the contracted state and in the shape of an open lantern skeleton in the deployed state.

[0056] Further, the inner end of the radial telescopic mechanism 8 is connected to the truss base 6 specifically as follows: the radial telescopic mechanism 8, from the inner diameter to the outer diameter, consists of: a first base telescopic rod fixing frame 11, a first limiting sleeve 13, an electromagnetic puller 17, a radial telescopic outer rod 14, a second limiting sleeve 18, a radial telescopic inner rod 16, a second base telescopic rod fixing frame 20, and a second telescopic rod connector 19; the first base telescopic rod fixing frame 11 and the second base telescopic rod fixing frame 20 are fixed to the truss base 6 by bolts and nuts, and the radial telescopic outer rod 14 is also fixed; a first limiting sleeve 13 and a second limiting sleeve 18 are threaded to each end of the radial telescopic outer rod 14, and after the sleeves are screwed in, their end faces form a limiting step in the inner cavity of the outer rod.

[0057] Furthermore, the radial telescopic inner rod 16 is a stepped round rod, with its large diameter section fitting the inner diameter of the radial telescopic outer rod 14 and its small diameter section fitting the inner diameter of the second limiting sleeve 18. When the radial telescopic inner rod 16 slides between the two sleeves, its shoulder end face abuts against the end faces of the front and rear sleeves respectively, thereby limiting the two extreme positions of contraction and extension, and realizing bidirectional mechanical limiting. A slot 15 is opened on the large diameter section of the radial telescopic inner rod 16, and an electromagnetic pin puller 17 is installed in the slot 15. A corresponding annular groove 21 is provided on the inner wall of the radial telescopic outer rod 14. When the main body of the truss mechanism is in the contracted state, the pin head of the electromagnetic pin puller 17 extends out and gets into the annular groove 21, locking the radial telescopic inner rod 16 in the contracted position. When the main body of the truss mechanism needs to be extended, the electromagnetic pin puller 17 is energized to unlock, the pin head is dislodged from the annular groove 21, and the radial telescopic inner rod 16 can slide freely axially within the radial telescopic outer rod 14.

[0058] Furthermore, the axial telescopic mechanism 9 is radially fitted with three layers of rods from the outside to the inside: the outer axial rod 32, the second axial rod 33, and the third axial rod 35. Similar to the radial telescopic mechanism 8, the axial telescopic mechanism 9 also uses a limiting sleeve to achieve bidirectional mechanical limiting.

[0059] Furthermore, an axial outer layer rod 32 is fitted with an axial outer layer rod bottom sleeve 31 at one end near the rigid section 3 of the space capsule. The axial outer layer rod bottom sleeve 31 serves as a bottom limit for the axial second layer rod 33 and as a connection interface, which is fixed to the first connecting bent rod 22-2 near the rigid section 3 of the space capsule by threads.

[0060] Furthermore, the axial second-layer rod 33 is a composite structure, consisting of two threaded parts with different diameters: the part with a larger thread diameter is adapted to the inner diameter of the axial outer-layer rod 32, and the part with a smaller thread diameter is a tubular round rod whose outer diameter is adapted to the inner diameter of the axial second-layer rod limiting sleeve 34; the larger diameter part has an annular step 37 machined at the end connected to the smaller diameter section, and the annular step 37 extends into the interior of the tubular round rod of the smaller diameter section to limit and abut against the bottom end face of the axial third-layer rod 35.

[0061] Furthermore, the axial triple-layer rod 35 is located inside the axial double-layer rod 33, and its bottom end face abuts against the annular step 37, thereby achieving bottom limiting. That is, when the axial triple-layer rod 35 is in the retracted state, the end face of its large-diameter section falls exactly on the annular step 37, preventing it from coming off the bottom of the axial double-layer rod 33. When unfolded, the axial triple-layer rod 35 slides upward until its large-diameter end face touches the end face of the axial triple-layer rod limiting sleeve 36, reaching the unfolded limit position. Through the above-mentioned three-layer hierarchical stacking and limiting cooperation, the axial telescopic mechanism can achieve multi-stage axial stretching and unfolding, and after each stage extends to its full position, its limit position is limited by the corresponding limiting sleeve.

[0062] Furthermore, the axial second-layer rod limiting sleeve 34 and the axial third-layer rod limiting sleeve 36 are evenly distributed with mounting holes at 120° intervals around the circumference. A hexagonal skeleton connector 41 is installed at each mounting hole by a threaded fixing pin 42 and two fixing nuts. Each limiting sleeve has a total of three hexagonal skeleton connectors, of which two inner adjacent connectors are used to connect to the hexagonal skeleton telescopic mechanism 10, and the other outer connector is used to connect to the inner fixing interface 43 of the flexible airbag.

[0063] Furthermore, each of the limiting sleeves is provided with three hexagonal skeleton connectors 41 that are 120° apart, wherein two adjacent hexagonal skeleton connectors 41 are used to connect the hexagonal skeleton telescopic mechanism 10, and the other hexagonal skeleton connector 41 is used to connect the inner wall of the flexible airbag.

[0064] A radial-axial deployment method for a flexible spacecraft, characterized by the following steps:

[0065] 1) All telescopic rods of the truss mechanism are in a fully retracted state: In the radial telescopic mechanism, the electromagnetic pin puller is energized and locked, the pin head extends and engages in the annular groove on the inner wall of the outer rod, locking the radial telescopic inner rod in the retracted position; in the axial telescopic mechanism, each layer of rods is stacked and retracted step by step, and each layer of limiting sleeves is in an initial non-contact state; the hexagonal frame telescopic mechanism is also in a retracted and locked state. Each limiting sleeve and the shoulder limiting surface of the stepped rod maintains a slight gap in the retracted state, ensuring that each rod can slide freely after unlocking. Check the tightness of each threaded fixing pin and connector to confirm there is no looseness.

[0066] 2) Orbital insertion and separation: After the rocket launches, it enters the predetermined orbit and the fairing is jettisoned; the onboard avionics system issues a separation command, the capsule separates from the rocket, and the control circuit inside the capsule receives the signal;

[0067] 3) Unlocking the pin pullers: After receiving the separation signal, the control circuit immediately outputs an unlocking command to each electromagnetic pin puller. The electromagnetic pin pullers are energized and actuate, the pin head exits from the annular groove on the inner wall of the outer rod, the radially telescopic inner rod is released from constraint, and the entire truss mechanism changes from a locked state to a freely movable state;

[0068] 4) Airbag Inflation and Truss Deployment: The control circuit drives the solenoid valve to open, and the high-pressure gas cylinder inflates the cabin. The gas is evenly released through pipelines to reduce disturbance to the cabin's attitude. As the flexible airbag gradually inflates, the inner wall of the airbag pulls the axial telescopic mechanisms and the hexagonal skeleton telescopic mechanism outward through the hexagonal skeleton connector. The specific deployment process is as follows: The hexagonal skeleton telescopic mechanism first extends radially under the action of the airbag inflation force; at the same time, the rods in each layer of the axial telescopic mechanism are pulled out step by step—the second axial rod slides out relative to the outer axial rod, and after it is in place, its second-layer limiting sleeve abuts against the bottom sleeve or limiting step of the outer axial rod, realizing the first level of limiting; the third axial rod continues to slide out relative to the second axial rod until its bottom end face abuts against the inner step of the large diameter section of the second axial rod, while its top touches the third-layer limiting sleeve, realizing the second level of bidirectional limiting. During this process, the six radial telescopic mechanisms on the base are simultaneously subjected to force and extend outward radially. After the stepped shoulders of each inner rod contact the end face of the corresponding limiting sleeve, they reach the unfolded state.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, and improvements 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 radially and axially deployable truss mechanism for use in a flexible space capsule, the truss mechanism comprising: The adapter frame (5) and the main body of the truss mechanism are characterized in that: one side of the adapter frame (5) is connected to the rigid section (3) of the flexible space capsule, and the other side is connected to the main body of the truss mechanism. The main body of the truss mechanism is a synchronous bidirectional unfolding truss mechanism; the synchronous bidirectional unfolding truss mechanism includes: multiple axial telescopic mechanisms (9) evenly distributed along the circumference and extending vertically, radial telescopic mechanisms (8) arranged at both ends of the multiple axial telescopic mechanisms (9), truss base (6) for supporting the radial telescopic mechanisms (8), and hexagonal skeleton telescopic mechanism (10); the axial unfolding of the main body of the truss mechanism is achieved through the axial telescopic mechanism (9); the radial unfolding of the main body of the truss mechanism is achieved through the radial telescopic mechanism (8); the hexagonal skeleton telescopic mechanism (10) is used to connect the middle rods of adjacent axial telescopic mechanisms (9) to form a circumferential constraint; when unfolded, it extends outward synchronously with the axial telescopic mechanism (9), connecting each independent axial telescopic mechanism into an integral space frame, serving as a lateral tie between multiple axial telescopic mechanisms (9), so that the entire skeleton changes from "multiple independent columns" to "integrated space frame"; The radial telescopic mechanism (8) is composed of multiple first radial telescopic mechanisms (8-1) and multiple second radial telescopic mechanisms (8-2); the multiple first radial telescopic mechanisms (8-1) are arranged at one end of the multiple axial telescopic mechanisms (9), and the multiple second radial telescopic mechanisms (8-2) are arranged at the other end of the multiple axial telescopic mechanisms (9); The truss base (6) includes a first truss base (6-1) for supporting a plurality of first radial telescopic mechanisms (8-1) and a second truss base (6-2) for supporting a plurality of second radial telescopic mechanisms (8-2); the first truss base (6-1) and the second truss base (6-2) are arranged opposite each other along the axial direction of the axial telescopic mechanism (9), the first truss base (6-1) is located on the outer end face of the first radial telescopic mechanism (8-1), and the second truss base (6-2) is located on the outer end face of the second radial telescopic mechanism (8-2). Each of the axial telescopic mechanisms (9) is disposed between the first truss base (6-1) and the second truss base (6-2); and one end of each of the axial telescopic mechanisms (9) is connected to the corresponding first radial telescopic mechanism (8-1) through the first connecting bent rod (22-1), and the other end is connected to the corresponding second radial telescopic mechanism (8-2) through the second connecting bent rod (22-2). The multiple axial telescopic mechanisms (9) are arranged circumferentially to form the longitudinal ribs of the lantern frame; The inner end of the radial telescopic mechanism (8) is connected to the truss base (6), and the outer end extends radially outward and is connected to the corresponding end of the corresponding axial telescopic mechanism (9). The axial telescopic mechanism (9) and the radial telescopic mechanism (8) are synchronously deployed by the inflation and expansion of the flexible airbag. The main body of the truss mechanism is in the shape of a folded lantern skeleton in the contracted state and in the shape of an open lantern skeleton in the deployed state.

2. The radially and axially deployable truss mechanism for a flexible space capsule according to claim 1, characterized in that, The inner end of the radial telescopic mechanism (8) is connected to the truss base (6) in the following ways: the radial telescopic mechanism (8) consists of the following components from the inner diameter to the outer diameter: a first base telescopic rod fixing frame (11), a first limiting sleeve (13), an electromagnetic puller (17), a radial telescopic outer rod (14), a second limiting sleeve (18), a radial telescopic inner rod (16), a second base telescopic rod fixing frame (20), and a second telescopic rod connector (19); the first base telescopic rod fixing frame (11) and the second base telescopic rod fixing frame (20) are fixed to the truss base (6) by bolts and nuts, and the radial telescopic outer rod (14) is fixed at the same time; a first limiting sleeve (13) and a second limiting sleeve (18) are threaded to each end of the radial telescopic outer rod (14), and after the sleeve is screwed in, its end face forms a limiting step in the inner cavity of the outer rod.

3. A radially and axially deployable truss mechanism for a flexible space capsule according to claim 2, characterized in that, The radial telescopic inner rod (16) is a stepped round rod. Its large diameter section matches the inner diameter of the radial telescopic outer rod (14), and its small diameter section matches the inner diameter of the second limiting sleeve (18). When the radial telescopic inner rod (16) slides between the two sleeves, its shoulder end face abuts against the end faces of the front and rear sleeves respectively, thereby limiting the two extreme positions of contraction and extension, and realizing bidirectional mechanical limiting. A slot (15) is opened on the large diameter section of the radial telescopic inner rod (16), and an electromagnetic pin puller (17) is installed in the slot (15). A corresponding annular groove (21) is provided on the inner wall of the radial telescopic outer rod (14). When the main body of the truss mechanism is in the contracted state, the pin head of the electromagnetic pin puller (17) extends out and is inserted into the annular groove (21), locking the radial telescopic inner rod (16) in the retracted position. When the main body of the truss mechanism needs to be unfolded, the electromagnetic pin puller (17) is energized to unlock, the pin head is dislodged from the annular groove (21), and the radial telescopic inner rod (16) can slide freely axially within the radial telescopic outer rod (14).

4. A radially and axially deployable truss mechanism for a flexible space capsule according to claim 1, characterized in that, The axial telescopic mechanism (9) is fitted with three layers of rods in the radial direction from the outside to the inside: the outer axial rod (32), the second axial rod (33), and the third axial rod (35). Similar to the radial telescopic mechanism (8), the axial telescopic mechanism (9) also uses a limiting sleeve to achieve bidirectional mechanical limiting.

5. A radially and axially deployable truss mechanism for a flexible space capsule according to claim 4, characterized in that: The outer axial rod (32) is fitted with an axial outer rod bottom sleeve (31) at one end near the rigid section (3) of the space capsule. The axial outer rod bottom sleeve (31) serves as a bottom limit for the axial second rod (33) on the one hand, and as a connection interface on the other hand, it is fixed to the first connecting bent rod (22-2) near the rigid section (3) of the space capsule by means of threads.

6. The radially and axially deployable truss mechanism for a flexible space capsule according to claim 4, characterized in that: The axial second-layer rod (33) is a composite structure, consisting of two threaded parts with different diameters: the part with a larger thread diameter is adapted to the inner diameter of the axial outer layer rod (32), and the part with a smaller thread diameter is a tubular round rod whose outer diameter is adapted to the inner diameter of the axial second-layer rod limiting sleeve (34); the larger diameter part has an annular step (37) machined at the end connected to the smaller diameter section, and the annular step (37) extends into the interior of the tubular round rod of the smaller diameter section to limit and abut against the bottom end face of the axial third-layer rod (35).

7. A radially and axially deployable truss mechanism for a flexible space capsule according to claim 4, characterized in that: The axial three-layer rod (35) is inside the axial two-layer rod (33), and its bottom end face abuts against the annular step (37), thereby achieving bottom limiting. That is, when the axial three-layer rod (35) is in the retracted state, the end face of its large diameter section falls exactly on the annular step (37), preventing it from coming out of the bottom of the axial two-layer rod (33). When unfolded, the axial three-layer rod (35) slides upward until its large diameter end face touches the end face of the axial three-layer rod limiting sleeve_36, reaching the unfolding limit position. Through the above three-layer stacking and limiting cooperation, the axial telescopic mechanism can realize multi-stage axial stretching and unfolding, and after each stage extends into place, its limit position is limited by the corresponding limiting sleeve.

8. A radially and axially deployable truss mechanism for a flexible space capsule according to claim 4, characterized in that: On the axial double-layer rod limiting sleeve (34) and the axial triple-layer rod limiting sleeve (36), there are mounting holes evenly distributed in the circumferential direction at 120° intervals. At each mounting hole, a hexagonal skeleton connector (41) is installed by a threaded fixing pin (42) and two upper and lower fixing nuts. There are three hexagonal skeleton connectors on each limiting sleeve. Two of the inner adjacent connectors are used to connect the hexagonal skeleton telescopic mechanism (10), and the other outer connector is used to connect the inner fixing interface (43) of the flexible airbag.

9. A radially and axially deployable truss mechanism for a flexible space capsule according to claim 7, characterized in that, Each of the limiting sleeves is provided with three hexagonal skeleton connectors (41) that are 120° apart. Two adjacent hexagonal skeleton connectors (41) are used to connect the hexagonal skeleton telescopic mechanism (10), and the other hexagonal skeleton connector (41) is used to connect the inner wall of the flexible airbag.

10. A method for radially and axially deploying a flexible spacecraft based on a radially and axially deployable truss mechanism according to any one of claims 1-9, characterized in that, Includes the following steps: 1) All telescopic rods of the truss mechanism are in a fully retracted state: In the radial telescopic mechanism, the electromagnetic pin puller is energized and locked, the pin head extends and engages in the annular groove on the inner wall of the outer rod, locking the radial telescopic inner rod in the retracted position; in the axial telescopic mechanism, each layer of rods is stacked and retracted step by step, and each layer of limiting sleeves is in an initial non-contact state; the hexagonal skeleton telescopic mechanism is also in a retracted and locked state; each limiting sleeve and the shoulder limiting surface of the stepped rod maintain a small gap in the retracted state to ensure that each rod can slide freely after unlocking; check the tightness of each threaded fixing pin and connector to confirm that there is no looseness; 2) Orbital insertion and separation: After the rocket launches, it enters the predetermined orbit and the fairing is jettisoned; the onboard avionics system issues a separation command, the capsule separates from the rocket, and the control circuit inside the capsule receives the signal; 3) Unlocking the pin puller: After receiving the separation signal, the control circuit immediately outputs an unlocking command to each electromagnetic pin puller; the electromagnetic pin puller is energized and the pin head exits from the annular groove on the inner wall of the outer rod, the radial telescopic inner rod is released from constraint, and the entire truss mechanism changes from the locked state to the free movable state. 4) Airbag Inflation and Truss Deployment: The control circuit drives the solenoid valve to open, and the high-pressure gas cylinder inflates the cabin. The gas is evenly released through pipelines to reduce disturbance to the cabin's attitude. As the flexible airbag gradually inflates, the inner wall of the airbag pulls the axial telescopic mechanisms and the hexagonal skeleton telescopic mechanism outward through the hexagonal skeleton connector. The specific deployment process is as follows: the hexagonal skeleton telescopic mechanism first extends radially under the action of the airbag inflation force; at the same time, the rods in each layer of the axial telescopic mechanism are pulled out step by step—the second-layer axial rod slides out relative to the outer layer axial rod, and after reaching its position, its second-layer limiting sleeve and... The outermost axial rod's bottom sleeve or limiting step abuts, achieving the first level of limiting; the third axial rod continues to slide out relative to the second axial rod until its bottom end face abuts against the inner step of the large-diameter section of the second axial rod, while its top touches the third limiting sleeve, achieving the second level of bidirectional limiting; during this process, the six radial telescopic mechanisms on the base are simultaneously subjected to force and extend outward radially, and the stepped shoulders of each inner rod touch the end face of the corresponding limiting sleeve and reach the extended limit position; after all telescopic rods are fully extended, a complete hexagonal honeycomb support skeleton is formed.

Images