Large scale space structure on-orbit construction system and method

Abstract

A large-scale space structure on-orbit construction system and method belong to the field of space on-orbit manufacturing and assembly, and adopts a mobile construction platform integrating manufacturing, assembly and material storage functions as a core mobile base. A continuous operation mode of "building while walking" is realized, the platform can move along the built structure, the manufacturing and assembly process can follow, the construction efficiency of large-scale structure is significantly improved, and the complex process of traditional multiple launches and multiple on-orbit docking is avoided. The manufacturing and assembly units are concentrated, the transfer distance of components from output to installation is shortened, the built-in material unit realizes the nearby supply of raw materials and prefabricated parts, the task adaptability can be enhanced, and different configuration of large-scale structure construction requirements can be flexibly adapted.

Description

Technical Field

[0001] This invention relates to a large-scale space structure on-orbit construction system and method, belonging to the field of space on-orbit manufacturing and assembly. Background Technology

[0002] Existing large-scale space structures, such as solar arrays and large-area antennas, all employ a ground-based manufacturing, single-launch launch, and on-orbit deployment model. However, this model limits the size and area of ​​the space structures. For example, the area of ​​a ground-based, single-deployment solar array is limited to 100m². 2 Ground-based fabrication, multiple launches, module assembly, and space expansion are time-consuming, costly, and slow-responding. With the significant increase in power demands from payloads, the solar array area needs to achieve scalable power output. The existing ground-based manufacturing-launch-space deployment / assembly model for solar array technology can no longer sustainably meet these demands.

[0003] In the future, large-scale solar arrays will reach sizes of hundreds of meters or even tens of kilometers, with their supporting structures primarily being space trusses. The scale of these large-scale space truss structures is far larger than the envelope size of a launch vehicle, making single-launch orbit insertion impossible. The traditional model of ground manufacturing, single launch, and in-orbit deployment is insufficient to meet engineering requirements. In-orbit construction is a crucial technological approach for the development of large-scale space structures. In-orbit construction involves the processing and assembly of raw materials or building modules into a space facility by manufacturing equipment in a target orbit or on an extraterrestrial body. Because in-orbit constructed space facilities do not require launch into orbit via a launch vehicle, the space structure does not need to withstand the harsh mechanical environment of the launch phase, effectively reducing the weight of the spacecraft structure. Furthermore, it is not limited by the envelope size of the launch vehicle fairing, thus greatly expanding the feasible domain for optimized design of space facility structures and enabling the construction of large-scale space structures that are impossible with traditional technologies. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an integrated, mobile, and highly autonomous on-orbit construction system and method for large-scale spatial structures. This system can directly manufacture the main truss structure from raw materials on-orbit and automatically assemble it, thereby realizing the efficient and reliable construction of ultra-large-scale spatial structures.

[0005] The objective of this invention is achieved through the following technical solutions: In a first aspect, the present invention provides an on-orbit construction system for large-scale spatial structures, comprising a mobile construction platform, a manufacturing unit, a space assembly unit, and a material unit. The mobile construction platform serves as the mobile base and integrated platform for the entire system. Its bottom is equipped with a walking mechanism for precise movement on the existing main truss. This walking mechanism includes at least two pairs of clamping wheel sets, each consisting of an active drive wheel and a driven clamping wheel, driven by a servo motor and equipped with a high-precision encoder for displacement feedback. The manufacturing unit is fixedly located at the front end of the mobile construction platform (referring to the structural growth section relative to the platform's direction of movement) and includes a rapid prototyping module and an additive manufacturing module.

[0006] The rapid prototyping module is used for the continuous manufacturing of standard members of the truss structure and for the welding and forming of the truss units. This module specifically includes the following sub-functional modules: The beam feeding module is used to store and supply thermoplastic prepreg tape (preferably 50mm wide and 0.2mm thick carbon fiber reinforced PEEK prepreg tape). The core of this module is to solve the problem of stable transportation of flexible tape under microgravity conditions in space. Internally, it includes a tape reel, a pre-tensioning mechanism, guide rollers, and a tape splicing station. The pre-tensioning mechanism applies a constant tension of 5-20N to the tape, preventing it from drifting, loosening, or knotting under microgravity. The guide rollers have a microtextured surface to increase friction and ensure straight tape output.

[0007] The prestress-assisted pultrusion forming and ultrasonic welding functional module (hereinafter referred to as the welding functional module) integrates forming and welding functions. First, two flat strips from the beam feeding functional module are fed into a set of heated forming dies with specific cross-sectional cavities (e.g., "C" or "I" type). The die temperature is controlled above the melting point of the prepreg base resin (380°C-400°C for PEEK). After softening under heat, the strips are drawn through the cavities, initially forming beam preforms with the target interface shape. The two formed beam preforms are precisely aligned and enter the ultrasonic welding head's action area. High-frequency vibration and friction generate heat, causing the resin at the contact surface of the two beam preforms to melt and bond instantaneously, forming a complete closed-section beam. This process is carried out under prestress, which helps improve the fiber orientation and ultimately the critical axial mechanical properties of the composite material.

[0008] Truss structure pushing function module: Located downstream of the welding function module, it is used to clamp and stably push the formed crossbeam. This module adopts a double-sided synchronous chain drive mechanism, with flexible clamping blocks on the chain that match the crossbeam cross-section. The clamping force is adjustable and controlled by a closed-loop force sensor to ensure that the crossbeam does not slip during the pushing process and that its surface is not damaged. The pushing speed is synchronized with the welding forming speed for coordinated control.

[0009] The additive manufacturing module is used to manufacture complex connection structures, nodes, or irregularly shaped components that cannot be mass-produced using the rapid prototyping module. Specifically, this module includes: Seven-axis robotic arm: It has six rotary joints and one linear motion joint, with a repeatability accuracy better than ±0.05 mm and a working radius of not less than 2 meters. The robotic arm is fixed on a movable construction platform.

[0010] Space-Specific End Effector (Printhead): This actuator integrates a filament feeding mechanism, a heated melting chamber, micro-extrusion nozzles, a filament cutting mechanism, and multiple sensors. The filament feeding mechanism employs dual drive wheels for counter-current filament feeding, ensuring controllable filament force to address the "bird's nest" phenomenon that may occur with the filament under microgravity. The heated melting chamber utilizes high-power ceramic resistance thermometers, achieving a maximum temperature of 450°C (suitable for PEEK printing), and is controlled in a closed-loop temperature loop by a high-precision thermocouple closely attached to the melting chamber. The filament cutting mechanism uses a micro-servo motor to drive rotating blades, cleanly cutting the filament during printing pauses or filament changes, preventing residual filament from interfering with printing under microgravity.

[0011] Space Environment Printing Platform: To overcome the problem of poor adhesion of the first layer when printing under microgravity, the printing platform is designed as follows: The platform substrate is a heating plate with controllable temperature (120°C-150°C for PEEK). Above the heating plate is a detachable metal dot matrix base plate. The dot matrix structure increases the contact area and mechanical interlocking effect between the molten material and the base plate.

[0012] Active cooling module: Due to the lack of air convection in the vacuum of space, heat dissipation is slow, affecting the bonding between printing layers and dimensional accuracy. This module sets up a ring-shaped contact heat sink 10-20mm behind the extrusion nozzle. The heat sink is made of a high thermal conductivity material (such as copper) and has a fluid cooling circuit inside. Through active circulation, the heat of the deposited material is quickly carried away, promoting its rapid solidification and setting.

[0013] On-orbit inspection and material replacement module: The inspection module includes an infrared thermal imager for monitoring the printing area (monitoring the melt pool temperature and thermal field distribution) and a high-resolution vision camera (for detecting printing defects such as interlayer cracks and porosity). The material replacement module is an independent filament storage and docking mechanism. When the current filament roll is exhausted, the robotic arm can move the print head to the material replacement module position to automatically complete the process of pulling out the residual filament ends of the old filament roll and cleaning, cutting, and docking (using thermal fusion docking) the filament ends of the new filament roll. The entire process requires no manual intervention.

[0014] The space assembly unit is located on the upper part of the movable construction platform and includes a space robot module, a measurement module, and a control module.

[0015] The space robot module comprises a main robot with seven degrees of freedom, featuring a standard quick-connect end effector flange interface. The platform is equipped with an integrated end effector tool library containing various end effectors, including: a three-finger adaptive gripper for grasping large trusses; a dexterous hand integrating a six-dimensional force / torque sensor and micro-manipulator for precision assembly; a universal gripper for changing raw materials and printing plates in manufacturing units; and an end effector crawling mechanism for enabling the robot to climb and move along the existing truss structure. This crawling mechanism is a key innovation of this module; its end effector is an adapter that locks onto the truss members. Through a "clamp-release-move" stepping mechanism, the robot can detach from the construction platform and move extensively along the truss structure to perform cross-platform inspection, repair, or assembly tasks.

[0016] Measurement Module: Contains at least one high-precision laser 3D vision sensor. This sensor is used not only for pose measurement and target recognition of the assembly target, but also specifically for online measurement during the on-orbit manufacturing process. For example, after the rapid prototyping module manufactures a section of truss, the measurement module immediately scans and measures the position of its key nodes and the straightness of its members, feeding the data back to the control module for comparison with the digital model, forming a closed loop of "manufacturing-measurement-compensation" to ensure the accuracy of the reference for subsequent assembly.

[0017] The control module serves as the core decision-making and control hub of the system, integrating multi-task scheduling software, motion planning algorithms, and closed-loop control algorithms. It receives real-time data from the measurement module, controlling not only the precision assembly movements of the space robot module but also coordinating the walking mechanism of the mobile construction platform with the work rhythm of the manufacturing units. For example, after a truss section is manufactured and assembled, the control module instructs the construction platform to move forward by the length of one truss unit (e.g., 2 meters), while simultaneously instructing the manufacturing unit to begin manufacturing the next truss section, achieving a streamlined collaborative operation of manufacturing, assembly, and movement.

[0018] The material unit is located inside the mobile construction platform and includes a raw material warehouse for on-orbit manufacturing of trusses and a functional component warehouse.

[0019] On-orbit manufacturing raw material warehouse for trusses: Utilizing a modular shelving design, it stores thermoplastic prepreg strip rolls (each roll capable of manufacturing at least 100 meters of longitudinal beams) required for rapid prototyping modules and high-performance polymer filament rolls (such as PEEK filament, 1.75mm in diameter) required for additive manufacturing modules. Each material roll has an independent identification tag (such as an RFID tag), and is retrieved and replaced as needed by a space robot module.

[0020] Functional Component Library: This library stores critical functional components that cannot or are unsuitable for on-orbit manufacturing, such as thin-film solar cell rolls for flexible solar arrays, cable networks, and specific electrical connectors. These components are precision-manufactured and packaged on the ground and retrieved in orbit by space robots according to their assembly sequence.

[0021] Secondly, the present invention provides an on-orbit construction method for a large-scale space structure (taking a solar cell wing as an example) based on the above system, comprising the following steps: Step 1: System launch and orbit insertion. The main satellite and the on-orbit construction system (mobile construction platform and each unit) in a folded and compressed state are regularly stacked and sent into the predetermined orbit through a single launch mission.

[0022] Step 2: On-orbit Deployment and Initialization. After separation from the launch vehicle, the pyrotechnic locking device unlocks, and the mobile construction platform and its supporting units deploy into their working configuration. The space robot module grasps the initial anchor point, temporarily securing the construction platform to the initial main truss base of the host satellite. The system performs a full-function self-test, including power-on testing of each module, sensor calibration, and robotic arm zero-point calibration. After confirming normal operation, it awaits mission instructions.

[0023] Step 3: In-orbit manufacturing.

[0024] Step 3a: The control module generates the manufacturing task sequence. The rapid prototyping module starts, the longitudinal beam feeding module supplies strip, and the welding module continuously manufactures the main truss longitudinal beams of the specified cross-section according to the set process parameters (mold temperature 390°C, ultrasonic welding pressure 350N, time 1s), and outputs them at a constant speed (e.g., 5cm / s) through the push module. When the output length reaches the design length of one truss unit (e.g., 2 meters), the rapid prototyping module pauses.

[0025] Step 3b: Based on the digital model, the additive manufacturing module uses a seven-axis robotic arm to drive the print head and print the complex connectors required for the current construction stage on the printing platform along a set path (layer thickness 0.2mm, printing speed 30mm / s, nozzle temperature 410°C, substrate temperature 130°C). During the printing process, the heat dissipation module works continuously, and an infrared thermal imager monitors the state of the molten pool.

[0026] Step 4: On-orbit assembly.

[0027] Step 4a: The measurement module scans the newly manufactured main truss segment to confirm its geometric dimensions are within acceptable limits. The space robot module uses a large gripper end effector to pick up and transport this main truss segment to the assembly position, where it docks with the previously fixed main truss segment or the spacecraft base. The robot then switches to a dexterous hand equipped with a six-dimensional force sensor to perform precise orientation adjustment and fastening of the docking surface (e.g., inserting and tightening space-grade high-strength bolts).

[0028] Step 4b: The space robot module removes the cooled and formed connector from the printing platform of the additive manufacturing module and assembles it onto the designated node of the main truss. Simultaneously, the robot retrieves a crossbeam from the crossbeam feeding module, restores its shape and positions it using the crossbeam gripping and positioning module, and the welding module of the rapid prototyping module initiates spot welding mode to weld and fix the crossbeam to the longitudinal beam of the main truss, forming a complete truss unit.

[0029] Step 4c: The space robot module takes out the thin-film solar cell roll from the functional component library and assembles and connects its front end to the interface on the connector.

[0030] Step 5: Construction Platform Movement and Iterative Construction. After the current truss unit assembly and battery roll front-end connection are completed, the control module instructs the walking mechanism of the movable construction platform to move, releasing the clamping wheel set and driving the drive wheel to rotate, so that the entire platform moves forward precisely along the existing main truss by the length of one truss unit (2 meters), with positioning accuracy controlled within ±1mm. After the platform moves into position, its posture is locked.

[0031] Step 6: Repeated Iteration. The system repeats steps 3 and 4 to manufacture and assemble the next truss unit, while gradually unfolding the thin-film solar array rolls. Once the rolls are fully unfolded, the space robot performs the final assembly and fixation of their ends to the main truss.

[0032] Step 7: Complete construction. According to the mission plan (e.g., construct the other wing symmetrically), repeat steps 3 to 6 until the entire large-scale solar array system is completed and the system enters on-orbit operation.

[0033] Compared with the prior art, the present invention has the following advantages: (1) This invention achieves efficient continuous construction through an integrated mobile platform. The technical improvement lies in using a mobile construction platform that integrates manufacturing, assembly, and material storage functions as the core mobile base. It realizes a continuous operation mode of "building while moving". The platform can move along the existing structure, so that the manufacturing and assembly processes can follow closely, which significantly improves the construction efficiency of large structures and avoids the complex process of traditional multi-launch and multiple on-orbit docking. By centralizing the manufacturing and assembly units, the transfer distance of components from production to installation is shortened. The built-in material unit realizes the supply of raw materials and prefabricated parts nearby, which can enhance the adaptability of the mission and flexibly adapt to the construction needs of large-scale structures with different configurations.

[0034] (2) The manufacturing unit uses rapid prototyping modules to mass-produce standard truss members, and combines them with additive manufacturing modules to print complex nodes and irregular structures on demand. This allows each unit to leverage its own technological advantages and reduce reliance on prefabricated ground components.

[0035] (3) The multi-functional robot module integrates 3D vision to achieve intelligent autonomous assembly. The 3D vision system can accurately measure and identify the robot, workpiece, and environment, guiding the robot to complete operations such as grasping, alignment, and docking. The multi-functional robot can perform various tasks such as inspection, handling, and assembly, reducing the number of specialized equipment and system complexity. (4) By controlling the manufacturing and assembly collaboratively, the accuracy and stability of the entire construction process are ensured, and the global closed-loop control is realized. The links such as structural manufacturing, component handling, precise assembly, and platform relocation are connected into a controlled overall process, ensuring the precise connection of actions in each link and improving the engineering reliability and final product quality of the entire construction system. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the layout of the large-scale space structure on-orbit construction system described in this invention; Figure 2 This is a schematic diagram of the large-scale space structure on-orbit construction system described in this invention; Figure 3 This is a schematic diagram of the on-orbit construction process of the large-scale space structure described in this invention; Figure 4 This is a schematic diagram illustrating the completion of the on-orbit construction of the large-scale space structure described in this invention.

[0037] Numbering in the diagram: 1-Mobile construction platform, 2-Manufacturing unit, 2-1-Rapid prototyping module, 2-2-Additive manufacturing module, 3-Space assembly unit, 3-1-Space robot module, 3-2-Measurement module, 3-3-Control module, 4-Material unit, 4-1-Truss on-orbit manufacturing raw material library, 4-2-Functional component library, 5-Main truss, 6-Secondary truss, 7-Complex structural component, 8-Connector, 9-Solar array thin-film battery roll, 10-Main star. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0039] like Figure 1 and Figure 2As shown, a large-scale space structure on-orbit construction system includes a mobile construction platform 1, a manufacturing unit 2, a space assembly unit 3, and a material unit 4. The manufacturing unit 2 is located at the front end of the mobile construction platform 1, the space assembly unit 3 is located on the mobile construction platform 1, and the material unit 4 is located inside the mobile construction platform 1. The manufacturing unit includes a rapid prototyping module 2-1 and an additive manufacturing module 2-2. The rapid prototyping module 2-1 manufactures the truss support structure, and the additive manufacturing module 2-2 manufactures the complex connection structure. The space assembly unit 3 includes a space robot module 3-1, a measurement module 3-2, and a control module 3-3. The space robot module 3-1 includes a multi-functional robot and various end effectors. The measurement module 3-2 measures the space environment and feeds the measurement results back to the space robot. The control module 3-3 is responsible for the motion control of the space robot module 3-1 during assembly and the movement control of the construction platform 1. The material unit 4 includes a truss on-orbit manufacturing raw material library 4-1 and a functional component library 4-2, which are prepared and mounted on the ground.

[0040] The rapid prototyping module 2-1 includes sub-functional modules: a longitudinal beam feeding module, a truss structure pushing module, a crossbeam feeding module, a crossbeam gripping and positioning module, and a welding module. The composite material strip is selected as thermoplastic prepreg strip, which is used to manufacture supporting structural members through prestressed assisted pultrusion molding, and then connected to the truss in orbit via ultrasonic welding. At the start of operation, the strip is flat and is shaped into a longitudinal beam with a specific cross-sectional shape by the longitudinal beam feeding module. The welding module welds two pieces of prestressed strip into a single unit in the welding forming module. The truss structure pushing module pushes the formed longitudinal beam stably and evenly via chain drive. During the stable operation phase, the crossbeam feeding module uses a clip-like crossbeam storage structure to effectively achieve rapid replacement of old and new materials. The crossbeam gripping and positioning module removes the crossbeam from the feeding device, restores the flattened crossbeam to its original shape, clamps the crossbeam, moves and positions the restored crossbeam to the welding position, and then welds it to the formed longitudinal beam via the welding module.

[0041] The additive manufacturing module 2-2 includes the following sub-modules: a multi-axis robotic arm, an end effector, a printing platform, a guide rail, a heat dissipation module, a detection module, a material changing module, and a control module. The multi-axis robotic arm consists of one unit with full seven-axis linkage control, capable of driving the end effector along a pre-planned path. The end effector is heated by a high-power resistance thermometer and its temperature is detected using a high-precision thermocouple. The 3D printing material is heated and melted in the heating block, extruded through a nozzle, and deposited onto the printing platform. At the point where interruption is needed, a filament-cutting mechanism rotates to cut the filament, and the printing end moves to the next forming area. Preferably, the material is PEEK. The printing platform is positioned above the guide rail platform, supported by a lattice horizontal base plate, and has a heating plate underneath for temperature control.

[0042] The space assembly unit 3 includes a space robot module 3-1, a measurement module 3-2, and a control module 3-3, which performs on-orbit assembly of the structural components produced by the manufacturing unit. The space robot module 3-1 includes a multi-functional robot and various end effectors. The multi-functional robot has a built-in end-effector tool library, enabling the assembly and fixing of the truss structure, the replacement of raw materials, movement, and crawling. The measurement module 3-2 includes a three-dimensional vision sensor for assembly positioning and assembly accuracy measurement. The control module 3-3 is responsible for the motion control of the robotic arm during assembly and the movement control of the construction platform.

[0043] The material unit 4 includes a raw material library 4-1 for truss on-orbit manufacturing and a functional component library 4-2. The raw material library 4-1 includes prestressed strip raw materials required for preparation by the rapid prototyping module 2-1 and PEEK raw materials required for preparation by the additive manufacturing module 2-2. The raw materials for the rapid prototyping module 2-1 and the additive manufacturing module 2-2 are replaced by the space robot module 3-1. The functional component library 4-2 includes thin-film solar cell rolls, which are prepared on the ground.

[0044] The specific steps for the on-orbit construction of large-scale space-structured solar arrays are as follows: Step 1: Launch of the primary satellite 10 and the construction system into orbit. The primary satellite provides attitude control, communication, and power supply capabilities, and carries a power source with a certain power output. The construction system includes a mobile construction platform, manufacturing units, space assembly units, and material units. After being stacked in a regular pattern, they are launched into orbit in a single operation.

[0045] Step 2: On-orbit Deployment. The locking device is unlocked, the movable construction platform is deployed, fixed to the initial main truss, a system self-check is performed to confirm that the on-orbit construction system is in normal operating condition, system initialization is performed, manufacturing preparation is completed, and the system awaits mission instructions.

[0046] Step 3: In-orbit manufacturing. The space structure is manufactured using the rapid prototyping module 2-1 and the additive manufacturing module 2-2 in manufacturing unit 2. A manufacturing task sequence is generated, with the following steps: Step 3a: Rapid prototyping module 2-1 manufactures the main truss 5 and the secondary truss 6 to the specified length.

[0047] Step 3b: Additive manufacturing module 2-2 prints the required complex structural parts 7 and connectors 8 according to the task instructions.

[0048] Step 4: On-orbit assembly. The manufactured structural components are assembled using space assembly unit 3, space robot module 3-1. An assembly task sequence is generated, with the following steps: Step 4a: The main truss 5 is connected to the star body via the space robot module 3-1, and the mobile construction platform 1 moves to the designated position on the main truss 5.

[0049] Step 4b: The sub-truss 6 is assembled with the structural component 7 and the connector 8 using the space robot module 3-1. The thin-film solar cell roll is taken out from the functional component library 4-2. The front end of the thin-film solar cell roll 9 is assembled with the connector 8.

[0050] Step 4c: Wait for the solar cell array thin-film battery roll 9 to be fully deployed, and then use the space robot module 3-1 to assemble the rear end of the solar cell array thin-film battery roll 9 with the main truss 5.

[0051] The manufacturing and assembly of the single solar cell wing has been completed.

[0052] Step 5: The movable construction platform 1 moves to the next position on the main truss 5, and repeats steps 3 and 4 in the order of the symmetrical sides of the main star until the construction of the entire solar cell wing system is completed.

[0053] Step 6: In-orbit Operation. The large-scale space structure solar array was successfully constructed in orbit and put into operation.

[0054] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0055] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A large scale space structure on-orbit construction system, characterized in that, It includes a mobile construction platform (1), a manufacturing unit (2), a spatial assembly unit (3), and a material unit (4). The mobile construction platform (1) is the mobile base and integrated platform of the entire system. The bottom is equipped with a walking mechanism for precise movement on the completed main truss (5). The walking mechanism includes at least two pairs of clamping wheel sets. The clamping wheel sets are composed of active drive wheels and driven clamping wheels. They are driven by servo motors and equipped with high-precision encoders for displacement feedback. The manufacturing unit (2) is fixedly installed at the front end of the movable construction platform (1), and includes a rapid prototyping module (2-1) and an additive manufacturing module (2-2); the rapid prototyping module (2-1) is used to continuously manufacture standard members of the truss structure and complete the welding and forming of the truss unit; the additive manufacturing module (2-2) is used to manufacture complex connection structures, node parts or irregular components that cannot be mass-produced by the rapid prototyping module. The space assembly unit (3) is set on the upper part of the mobile construction platform (1) and includes a space robot module (3-1), a measurement module (3-2) and a control module (3-3). The measurement module (3-2) is used to perform pose measurement and target recognition on the assembly target and to perform online measurement in the on-orbit manufacturing process, and feeds the data back to the control module (3-3). The control module (3-3) controls the space robot module (3-1) and controls the walking mechanism of the mobile construction platform (1) and the working rhythm of the manufacturing unit (2). The material unit (4) is located inside the movable construction platform (1) and includes a truss on-orbit manufacturing raw material warehouse (4-1) and a functional component warehouse (4-2); the truss on-orbit manufacturing raw material warehouse (4-1) is used to store raw materials, and the functional component warehouse (4-2) stores components that cannot or are not suitable for on-orbit manufacturing.

2. The large scale space structure on-orbit construction system of claim 1, wherein, The rapid prototyping module (2-1) includes a beam feeding module, a welding module, and a truss structure pushing module. The beam feeding module is used to store and supply thermoplastic prepreg strips. The welding module is used to complete the welding. The truss structure pushing module is used to clamp and stably push the formed beam.

3. The large-scale space structure on-orbit construction system of claim 2, wherein, The welding module works as follows: two flat strips from the beam feeding module are fed into a heated forming mold with a cavity. The temperature of the heated forming mold is controlled above the melting point of the prepreg resin. After the strips soften from the heat, they are pulled through the cavity to initially form a beam blank with the target interface shape. The two formed beam blanks are precisely aligned and enter the ultrasonic welding head's action area. High-frequency vibration and friction generate heat, causing the resin at the contact surface of the two beam blanks to melt and bond instantly, forming a complete closed-section beam.

4. The large scale space structure on-orbit construction system of claim 2, wherein, The truss structure pushing function module adopts a double-sided synchronous chain drive mechanism. The chain is equipped with flexible clamping blocks that match the crossbeam cross section. The clamping force is adjustable and controlled by a closed loop force sensor to ensure that the crossbeam does not slip and the surface is not damaged during the pushing process. The pushing speed is synchronized with the welding forming speed and coordinated control.

5. The large scale space structure on-orbit construction system of claim 2, wherein, The additive manufacturing module (2-2) includes a seven-axis robotic arm, an end effector, a space environment printing platform, an active heat dissipation module, and an on-orbit detection and material changing module; The seven-axis robotic arm is fixed on a mobile construction platform (1); the end effector is used to realize printing; the space environment printing platform can provide a heated platform substrate and a detachable metal dot matrix base plate is set on the platform substrate; the active heat dissipation module is used for heat dissipation; the on-orbit detection and material changing module is used for detection and material changing.

6. The large scale space structure on-orbit construction system of claim 5, wherein, The seven-axis robotic arm has six rotary joints and one linear motion joint, with a repeatability better than ±0.05 mm and a working radius of not less than 2 meters.

7. The large scale space structure on-orbit construction system of claim 5, wherein, The end effector integrates a wire feeding mechanism, a heating and melting chamber, a wire cutting mechanism, and sensors. The wire feeding mechanism uses dual drive wheels to counteract the wire feeding, and the wire feeding force is controllable to cope with the "bird's nest" phenomenon that may occur in the wire under microgravity. The heating and melting chamber is heated by a high-power ceramic resistance thermometer, and the temperature is controlled in a closed loop by a sensor that is closely attached to the melting chamber. The filament cutting mechanism is driven by a micro servo motor to rotate the blade, which can cleanly cut the filament when printing is paused or when changing materials, avoiding residual filament from interfering with printing under microgravity.

8. The large-scale space structure on-orbit construction system according to claim 5, characterized in that, The active cooling module is a ring-shaped contact heat sink made of a high thermal conductivity material. It has an internal fluid cooling circuit that actively circulates the heat of the deposited material to quickly remove it.

9. The large-scale space structure on-orbit construction system according to claim 5, characterized in that, The detection module includes an infrared thermal imager and a high-resolution vision camera to monitor the printed area; the infrared thermal imager monitors the molten pool temperature and thermal field distribution; the high-resolution vision camera is used to detect printing defects. When the current filament roll is exhausted, the robotic arm can move the print head to the material changing module position to automatically pull out the residual filament ends of the old filament roll and clean, cut, and connect the filament ends of the new filament roll.

10. An on-orbit construction method of an on-orbit construction system of a large-scale space structure according to claim 5, characterized by, include: The space robot module (3-1) grabs the initial anchor point and temporarily fixes the construction platform (1) on the initial main truss (5) base of the main star (10); the on-orbit construction system performs a full-function self-check, and after confirming that the status is normal, it waits for mission instructions. The control module (3-3) generates a manufacturing task sequence; the rapid prototyping module (2-1) starts, the longitudinal beam feeding function module supplies strip material, the welding function module continuously manufactures the main truss longitudinal beam with a specified cross-section according to the set process parameters, and outputs it at a constant speed through the push function module; when the output length reaches the design length of a truss unit, the rapid prototyping module pauses; the additive manufacturing module (2-2) drives the print head with a seven-axis robotic arm according to the digital model, and prints the complex connectors (8) required for the current construction stage on the printing platform along the set path; during the printing process, the heat dissipation module works continuously, and the infrared thermal imager monitors the state of the molten pool; The measurement module (3-2) scans the newly manufactured main truss segment to confirm that its geometric dimensions are qualified; the space robot module (3-1) grabs and transports the main truss segment to the assembly position, docks it with the fixed previous main truss segment or star base, and completes the precise orientation adjustment and fastening of the docking surface; the space robot module (3-1) takes the cooled and formed connector (8) from the printing platform of the additive manufacturing module (2-2) and assembles it onto the designated node of the main truss; at the same time, the space robot module (3-1) takes a crossbeam from the crossbeam feeding function module, restores its shape and positions it through the crossbeam grabbing and positioning function module, and the welding function module of the rapid prototyping module (2-1) starts the spot welding mode to weld and fix the crossbeam to the longitudinal beam of the main truss to form a complete truss unit; the space robot module (3-1) takes the solar cell array thin film battery roll (9) from the functional component library (4-2) and assembles and connects it with the interface on the connector (8); After the current truss unit assembly and battery roll front end connection are completed, the control module (3-3) instructs the walking mechanism of the movable construction platform (1) to move, the clamping wheel group is released, the drive wheel rotates, so that the entire platform moves forward precisely along the main truss (5) by the length of one truss unit; after the platform moves into place, the posture is locked. The next truss unit is manufactured and assembled iteratively, while the solar cell array thin-film battery roll (9) is gradually unfolded. When the battery roll is fully unfolded, the space robot performs final assembly and fixation of its end to the main truss.

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