3D printing simulation test platform in vacuum microgravity environment and eddy current damping control method

Abstract

The present application relates to 3D printing simulation test platform, belongs to aerospace ground simulation experiment technical field, specifically is 3D printing simulation test platform under vacuum microgravity environment, contains five parts of guiding frame system, intelligent experiment load cabin, mixed variable gravity control system, eddy current safety recovery system and on-board synchronous data acquisition system, the guiding frame system is supported based on the tower that is vertically set up, the top support platform is fixedly installed on the top of tower, the bottom support platform is fixedly installed on the bottom, the tower body is assembled with low friction linear guide; The intelligent experiment load cabin is adapted and installed on the linear guide through the load cabin mounting seat. The present application can highly restore vacuum and microgravity composite extreme environment, quickly build vacuum experiment condition by built-in vacuum valve of intelligent experiment load cabin external suction equipment, cooperate with mixed variable gravity control system to realize low gravity accurate simulation, greatly reduce the cost and risk of space on-orbit experiment.

Description

Technical Field

[0001] This invention relates to the field of aerospace ground simulation experiment technology, and in particular to a 3D printing simulation test platform and eddy current damping control method under vacuum microgravity environment. Background Technology

[0002] With the rapid development of deep space exploration technology, the in-situ resource utilization and 3D printing manufacturing of extraterrestrial bodies such as the Moon (approximately 0.16g) and Mars (approximately 0.38g) have become a key research focus in the aerospace field. Changes in the gravitational environment directly alter the flow, spreading, shaping, and solidification behavior of molten materials, significantly impacting the printing quality and process stability.

[0003] Current ground-based low / microgravity simulation devices generally have significant limitations: traditional drop towers can only achieve short-term microgravity environments and cannot accurately match specific low-gravity conditions such as the Moon and Mars; they also have poor gravity adjustment capabilities and limited applicability. Conventional braking methods rely on mechanical friction, which is prone to stick-slip and impact vibrations, severely interfering with the precision 3D printing process. Pure motor-assisted reverse braking suffers from high energy consumption, slow response, and insufficient control precision. At the same time, existing experimental devices generally have problems such as short experimental duration, the cabin being in motion, and significant external interference. Traditional data acquisition methods are unable to achieve high-frequency, synchronous, and stable process data acquisition, which cannot meet the needs of 3D printing process verification and mechanism research in a vacuum low-gravity environment. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a solution for a 3D printing simulation testing platform under vacuum microgravity conditions.

[0005] The technical solution to achieve the purpose of this invention is as follows: The 3D printing simulation test platform under vacuum microgravity environment comprises five parts: a guide frame system, an intelligent experimental load chamber, a hybrid variable gravity control system, an eddy current safety recovery system, and an onboard synchronous data acquisition system. The guide frame system is based on a vertically erected tower, with a top support platform fixedly installed at the top and a bottom support platform fixedly installed at the bottom. Low-friction linear guides are mounted on the tower frame. The intelligent experimental load chamber is adapted and installed on the linear guides via a load chamber mounting seat. The hybrid variable gravity control system is integrated into the top support platform. The intelligent experimental payload chamber is equipped with a 3D printing extrusion mechanism and a micro melting furnace. The chamber is also equipped with multiple sets of environmental and process sensors, including high-frequency MU, thermocouples and ammeters. A high-speed camera is installed at the top of the intelligent experimental payload chamber.

[0006] In some embodiments, an outer baffle is provided on the outside of the intelligent experimental payload chamber, and a pulley mounting groove is provided on the payload chamber mounting base, with pulleys installed in the groove. This allows the intelligent experimental payload chamber to move only vertically along the Z-axis within the tower due to the restriction of the guide rail and pulleys. A vacuum valve is provided on the outer wall of the outer baffle of the payload chamber, and an external vacuum pumping device is connected to quickly remove the air from the chamber, thus creating a vacuum experimental environment.

[0007] In some embodiments, the hybrid variable gravity control system is integrated on the top support platform. The hybrid variable gravity control system includes a servo motor, an electromagnetic braking unit, a magnetic powder brake, a clutch, and a fixed pulley. The servo motor, electromagnetic braking unit, magnetic powder brake, clutch, and fixed pulley are coaxially connected in series on the top support platform. One end of the steel wire rope is fixedly connected to the top of the intelligent experimental payload chamber, and the other end passes around the fixed pulley and is fixedly connected to the counterweight assembly.

[0008] In some embodiments, the counterweight assembly includes a fixing groove, which is fixedly installed along the Z-axis on the side of the tower away from the intelligent experimental payload chamber. A counterweight box and an upper connecting bracket are slidably installed inside the fixing groove. A connecting lug is fixedly installed on the upper connecting bracket, and a counterweight guide rod is fixedly installed between the connecting lug and the counterweight box. Multiple sets of counterweight blocks are sleeved on the counterweight guide rod, and the counterweight blocks are located inside the internal cavity of the counterweight box. A movable pulley is rotatably installed inside the upper connecting bracket via a rotating shaft. The end of a steel wire rope away from the intelligent experimental payload chamber is wound and fixed to the movable pulley, and power is transmitted through the movable pulley and the connecting lug to drive the counterweight assembly to move synchronously up and down along the fixing groove.

[0009] In some embodiments, the flow safety recovery system includes an eddy current copper plate and a powerful magnet. The powerful magnet is fixedly installed as a mover on the outer wall of the intelligent experimental payload chamber, and the eddy current copper plate is fixedly laid as a stator along the Z-axis in the braking area at the bottom of the tower, corresponding to the position of the powerful magnet.

[0010] In some embodiments, the eddy current safety recovery system further includes a hydraulic buffer and a spring buffer, both of which are mounted on the bottom support platform.

[0011] In some embodiments, multiple sets of locking rods are fixedly installed on the top surface of the intelligent experimental payload chamber, and locking buckles are provided at the upper ends of the locking rods; multiple sets of mechanical locks matching the number of locking rods are fixedly installed on the bottom surface of the top support platform, and locking grooves are opened on the bottom surface of the mechanical locks. Multiple sets of spring columns are fixedly installed on the inner wall of the locking grooves. The multiple sets of spring columns are arranged in a circular array with the center of the locking groove as the center. Distributed card blocks are fixedly installed at the ends of the multiple sets of spring columns near the center of the locking groove. The distributed card blocks are arc-shaped claw structures.

[0012] In some embodiments, safety clamps are fixedly installed on both the left and right sides of the load chamber mounting base, corresponding to the low-friction linear guide rails of the tower.

[0013] In some embodiments, the onboard synchronous data acquisition system integrates a high-frequency IMU, thermocouples, and ammeters to complete high-frequency acquisition of multi-source parameters such as triaxial acceleration, attitude, and process temperature / current. A high-speed camera records visual images of the printing nozzle and melting interface, and all data is written in real time to the onboard anti-vibration storage card in the intelligent experimental payload chamber.

[0014] An eddy current damping control method for a 3D printing simulation test platform under vacuum microgravity environment: When a powerful magnet moves relative to an eddy current copper plate with the intelligent experimental load chamber, the magnetic flux passing through the eddy current copper plate changes, generating an induced electromotive force. The induced electromotive force satisfies: in, To induce electromotive force. The magnetic flux passing through the copper plate. The magnetic flux density of the magnet is . For a copper plate with a small area, the faster the magnet moves and the stronger the magnetic field, the greater the induced electromotive force generated within the copper plate. This provides the driving force for the generation of eddy currents. The induced electromotive force drives the generation of eddy currents within the copper plate, and the current density satisfies the following: The eddy current density, The conductivity of the copper plate is given by [insert value here]. For the induced electric field strength, The speed of movement of the intelligent experimental payload chamber 4. The magnetic flux density of the magnet; Eddy currents in a magnetic field experience a Lorentz force, and the reaction force of this force is the damping force acting on the load chamber. , This is the eddy current damping force. Let be the volume of the eddy current copper plate.

[0015] The direction of the damping force is opposite to the direction of motion of the load compartment, and the magnitude of the damping force is approximately equal to the motion velocity. Proportional, that is ,in The damping coefficient, determined by the magnetic field of the magnet, the parameters of the copper plate, and the relative area, enables adaptive deceleration; that is, the faster the speed, the greater the braking force. Combining the damping force, the dynamic equation for the descent of the payload compartment is: The total mass of the payload compartment. It is the acceleration due to gravity. The equation is used to calculate the changes in velocity and acceleration of the load chamber under eddy current damping as a function of the counterweight components, verify the pre-deceleration effect, and ensure that the speed of the chamber drops to a safe threshold before entering the hydraulic buffer. Through formula By working backward, the thickness, area, and material of the eddy current copper plate, as well as the magnetic field strength, number, and arrangement of the powerful magnets, are determined to ensure that the damping force meets the pre-deceleration requirements.

[0016] The significant advantages of this invention compared to existing technologies are: 1. This invention can highly replicate the extreme environment of vacuum and microgravity. By using an intelligent experimental payload chamber with a built-in vacuum valve and external pumping equipment, it rapidly constructs vacuum experimental conditions. Combined with a hybrid variable gravity control system, it achieves precise low-gravity simulation, realistically reproducing in-situ resource utilization and molten material 3D printing conditions in deep space exploration scenarios such as the Moon and Mars. Compared to the conventional 1g atmospheric gravity environment on Earth, using this platform to simulate the 0.16g low-gravity and high-vacuum composite environment of the Moon for 3D printing experiments can precisely control the equivalent gravitational acceleration to 0.16g ± 0.01g, with the vacuum level inside the chamber stably reaching 1×10⁻³ Pa, effectively meeting the requirements for lunar environment simulation. The density of the printed sample is increased from 92.0% to 95.2%, the dimensional error is reduced from ±0.30mm to ±0.05mm, and the surface roughness is reduced from 12.0μm. Optimized to 6.5μm, the molding quality and dimensional accuracy are significantly improved; the cabin motion acceleration fluctuation is controlled within ±0.015m / s², solving the problem that deep space 3D printing process verification cannot be carried out in conventional ground environments. It provides reliable ground experimental conditions for the research and development of aerospace-grade printing equipment, material selection, and process parameter optimization, greatly reducing the cost and risk of on-orbit experiments in space and improving the efficiency of deep space manufacturing technology research and development.

[0017] 2. In this invention, one end of the steel wire rope is fixedly connected to the top surface of the intelligent experimental payload chamber, and the other end passes upwards around the fixed pulley on the support platform at the top of the tower, and then is fixedly connected to the movable pulley in the counterweight assembly, forming a traction transmission link from the intelligent experimental payload chamber to the fixed pulley and then to the movable pulley; when the hybrid variable gravity control system is working, the servo motor outputs power as the active power source, which is transmitted to the fixed pulley through the electromagnetic braking unit, magnetic powder brake, and clutch. The clutch realizes the switching between the servo motor and the braking unit, and the electromagnetic braking unit is used for safety braking in emergency situations; when the fixed pulley rotates, the steel wire rope is wound and released, and the steel wire rope is wound and released through the steel wire rope. The retraction and deployment actions directly pull the intelligent experimental payload cabin, causing it to rise and fall vertically along the Z-axis on the low-friction linear guide rail of the tower. Simultaneously, the counterweight provided by the counterweight box and counterweight guide rods provides balancing gravity, achieving coarse adjustment and offsetting of the cabin's own weight through mechanical counterweighting. Then, a magnetic powder brake completes the precise fine adjustment of the lifting power, achieving precise control of the cabin's lifting power and lightweight traction. This ensures smooth cabin movement and controllable acceleration, effectively avoiding problems such as insufficient adjustment precision, slow braking response, and large movement impacts associated with traditional counterweight methods. It significantly improves the realism of microgravity simulation and the stability of the experimental process. Compared to the conventional 1g atmospheric gravity environment on Earth, this platform simulates the 0.16g low gravity and high vacuum composite environment of the moon for 3D printing experiments. The velocity before recovery drops to 0.42m / s, meeting the safety buffer threshold requirements. All indicators verify the platform's reliable practicality and engineering application value, ensuring the authenticity and reliability of the 3D printing experimental data.

[0018] 3. The eddy current safety recovery system of the present invention adopts non-contact eddy current damping to achieve adaptive deceleration. The greater the speed, the stronger the braking force. Combined with multi-stage buffering, it achieves soft landing of the cabin and avoids rigid impact. Mechanical locking ensures that the cabin is reliably fixed before the experiment starts. The safety clamp can be locked at any position in case of failure of the traction system, which comprehensively protects the safety of the cabin, experimental equipment and operators, and completely solves the safety hazards such as high-altitude falls, equipment damage and experiment interruption. The reliability and safety of the device operation are greatly improved.

[0019] 4. This invention is based on the principle of electromagnetic induction and quantitative dynamic calculation. It utilizes the relative motion between a powerful magnet and an eddy current copper plate to generate induced electromotive force and eddy currents, thereby forming an adaptive damping force that is opposite to the direction of descent and increases in magnitude with increasing speed. Combined with the dynamic equation of the payload compartment's descent, it can accurately simulate and verify the deceleration effect, reliably reducing the compartment's speed to a safe threshold. At the same time, it can reverse-engineer the parameter optimization and selection of the eddy current copper plate and the powerful magnet, ultimately achieving a non-contact, wear-free, and fast-response pre-deceleration effect. This provides a safe input for subsequent hydraulic buffering and effectively ensures the stability and safety of the intelligent experimental payload compartment and its internal 3D printing equipment during the vacuum microgravity simulation experiment recovery process.

[0020] 5. The onboard synchronous data acquisition system of this invention integrates multiple types of sensors such as high-frequency IMU, thermocouples, and ammeters. It can synchronously acquire key parameters such as triaxial acceleration, attitude, process temperature, and current. In conjunction with a high frame rate industrial camera, it records the working status of the printing nozzle and the molding process of molten material in real time. All data is stored in a shockproof black box mode, which effectively avoids data loss caused by recycling impact. It realizes full-process, high-frequency, and synchronous acquisition and retention of environmental and process parameters, providing complete and detailed data support for experimental analysis, process optimization, and fault tracing. Attached Figure Description

[0021] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall three-dimensional structure of the 3D printing simulation test platform under vacuum microgravity environment of the present invention; Figure 2 This is a three-dimensional structural diagram of the hybrid variable gravity control system of the present invention; Figure 3 This is a schematic diagram showing the position and structure of the spring buffer and the hydraulic buffer of the present invention; Figure 4 This is a schematic diagram showing the connection and distribution between the intelligent experimental load chamber and the tower of the present invention; Figure 5 This is a three-dimensional structural diagram of the counterweight component of the present invention; Figure 6 This is a schematic diagram showing the three-dimensional structure of the intelligent experimental payload chamber of the present invention. Figure 7 This is a schematic diagram of the three-dimensional structure of the mechanical locking mechanism on the bottom surface of the top support platform of the present invention; Figure 8 This is a three-dimensional structural diagram of the outer baffle of the load chamber of the present invention; Figure 9 This is a three-dimensional structural diagram of the load chamber mounting base and safety clamp of the present invention.

[0022] Explanation of reference numerals in the attached figures: 1. Bottom support platform; 2. Top support platform; 3. Tower; 4. Intelligent experimental load chamber; 5. Servo motor; 6. Electromagnetic braking unit; 7. Magnetic powder brake; 8. Clutch; 9. Fixed pulley; 10. Steel wire rope; 11. Load chamber outer baffle; 12. Load chamber mounting base; 13. Pulley mounting slot; 14. Pulley; 15. Locking rod; 16. Locking buckle; 17. Mechanical lock; 18. Locking groove; 19. Spring column; 20. Distributed locking block; 21. Spring buffer; 22. Eddy current copper plate; 23. Hydraulic buffer; 24. Fixing groove; 25. Counterweight box; 26. Connecting ear plate; 27. Counterweight guide rod; 28. Upper connecting bracket; 29. ​​Moving pulley; 30. Counterweight block; 31. Vacuum valve; 32. Safety clamp. Detailed Implementation

[0023] The present invention will now be described in detail, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1 This invention provides an improved 3D printing simulation testing platform under a vacuum microgravity environment. The technical solution of this invention is as follows: The 3D printing simulation test platform under vacuum microgravity environment consists of five parts: a guide frame system, an intelligent experimental load chamber, a hybrid variable gravity control system, an eddy current safety recovery system, and an onboard synchronous data acquisition system.

[0025] The guide frame system is based on a vertically erected tower 3. A top support platform 2 is fixedly installed on the top of the tower 3, and a bottom support platform 1 is fixedly installed on the bottom. Low-friction linear guide rails are mounted on the frame of the tower 3. The intelligent experimental load chamber 4 is adapted to be installed on the linear guide rails through the load chamber mounting seat 12. An outer baffle 11 is set on the outside of the intelligent experimental load chamber 4. A pulley mounting groove 13 is opened on the load chamber mounting seat 12, and a pulley 14 is installed in the groove, so that the intelligent experimental load chamber 4 can only move vertically along the Z-axis within the tower 3 due to the restriction of the guide rails and pulleys 14.

[0026] The hybrid variable gravity control system is integrated on the top support platform 2 and includes a servo motor 5, an electromagnetic braking unit 6, a magnetic powder brake 7, a clutch 8, and a fixed pulley 9. The servo motor 5, the electromagnetic braking unit 6, the magnetic powder brake 7, the clutch 8, and the fixed pulley 9 are installed in series on the top support platform 2 in a coaxial manner. One end of the steel wire rope 10 is fixedly connected to the top of the intelligent experimental load chamber 4, and the other end passes around the fixed pulley 9 and is fixedly connected to the counterweight assembly.

[0027] The counterweight assembly includes a fixing groove 24, which is fixedly installed along the Z-axis on the side of the tower 3 away from the intelligent experimental payload chamber 4. A counterweight box 25 and an upper connecting bracket 28 are slidably installed inside the fixing groove 24. A connecting lug 26 is fixedly installed on the upper connecting bracket 28, and a counterweight guide rod 27 is fixedly installed between the connecting lug 26 and the counterweight box 25. Multiple sets of counterweight blocks 30 are sleeved on the counterweight guide rod 27, and the counterweight blocks 30 are located in the internal cavity of the counterweight box 25. A movable pulley 29 is rotatably installed inside the upper connecting bracket 28 via a rotating shaft. The end of the steel wire rope 10 away from the intelligent experimental payload chamber 4 is wound and fixed to the movable pulley 29. Power is transmitted by the movable pulley 29 through the connecting lug 26 to drive the counterweight assembly to move up and down synchronously along the fixing groove 24.

[0028] One end of the steel wire rope 10 is fixedly connected to the top end face of the intelligent experimental load chamber 4, and the other end goes upward around the fixed pulley 9 on the top support platform 2 of the tower 3, and then is connected and fixed to the movable pulley 29 in the counterweight assembly, forming a traction transmission link from the intelligent experimental load chamber 4 to the fixed pulley 9 and then to the movable pulley 29; when the hybrid variable gravity control system is working, the servo motor 5 outputs power as the active power source, which is transmitted to the fixed pulley 9 through the electromagnetic braking unit 6, the magnetic powder brake 7, and the clutch 8. The clutch 8 realizes the switching between the servo motor 5 and the braking unit, and the electromagnetic braking unit 6 uses... Safety braking in emergency situations; when the fixed pulley 9 rotates, the steel wire rope 10 is wound up and down. The winding and unwinding action of the steel wire rope 10 directly pulls the intelligent experimental payload chamber 4, causing the intelligent experimental payload chamber 4 to rise and fall vertically along the Z-axis along the low-friction linear guide rail of the tower 3. At the same time, the counterweight box 25 and the counterweight block 30 on the counterweight guide rod 27 provide balancing gravity, and the coarse adjustment of the chamber's own weight is achieved by mechanical counterweight. Then, the magnetic powder brake 7 completes the precise fine adjustment of the lifting power, realizing precise control of the lifting power of the chamber and lightweight traction, ensuring smooth movement of the chamber and controllable acceleration.

[0029] The Intelligent Experimental Payload Chamber 4, serving as the process execution unit of the entire device, has a complete internal structure, directly simulating 3D printing and fluid physics experiments in a vacuum, low-gravity environment. It is equipped with a 3D printing extrusion mechanism and a micro-melting furnace to simulate the molten material forming process in deep-space in-situ resource utilization scenarios such as those on the Moon and Mars. The chamber also houses multiple sets of environmental and process sensors, including high-frequency MUs, thermocouples, and ammeters, to simultaneously collect key data such as acceleration, attitude, temperature, and current. A high-speed camera is installed at the top of the interior of the Intelligent Experimental Payload Chamber 4. The camera is aimed at the printing area to clearly record the extrusion morphology and solidification behavior of the molten material; a vacuum valve 31 is provided on the outer wall of the outer baffle 11 of the load chamber, and an external vacuum pumping device is connected to quickly remove the air in the chamber to create a vacuum experimental environment; the bottom of the intelligent experimental load chamber 4 is fixedly connected to the load chamber mounting base 12 by fasteners, and the mounting base has a pulley mounting groove 13, in which a pulley 14 is rotated and installed, so that the load chamber 4 and the guide rail of the tower 3 roll together to achieve low-friction vertical movement; the hybrid variable gravity control system directly drives the chamber to rise and fall through the rope traction to complete the entire process of the low gravity simulation experiment.

[0030] Furthermore, the eddy current safety recovery system includes an eddy current copper plate 22 and a powerful magnet 31. The powerful magnet 31 is fixedly installed on the outer wall of the intelligent experimental payload cabin 4 as a mover, and the eddy current copper plate is fixedly laid in the braking area at the bottom of the tower 3 along the Z-axis direction as a stator, corresponding to the position of the powerful magnet 31. When the experiment is completed and the intelligent experimental payload cabin 4 falls to the braking area at the bottom of the tower 3, the powerful magnet 31 moves at high speed across the eddy current copper plate with the cabin, generating an eddy current damping force opposite to the falling direction through electromagnetic induction, realizing non-contact adaptive pre-deceleration and significantly reducing the falling speed of the cabin.

[0031] Eddy current damping control method for 3D printing simulation test platform under vacuum microgravity environment, when the strong magnet 31 on the intelligent experimental load chamber 4 moves at a velocity When the copper plate 22 moves relative to the eddy current plate, the magnetic flux inside the copper plate changes, generating an induced electromotive force: To induce electromotive force. The magnetic flux passing through the copper plate. The magnetic flux density of the magnet is . For a copper plate with a small area, the faster the magnet moves and the stronger the magnetic field, the greater the induced electromotive force generated in the copper plate, which provides the driving force for the generation of eddy currents.

[0032] The induced electromotive force drives eddy currents within the copper plate, and the current density satisfies: The eddy current density, The conductivity of the copper plate is given by [insert value here]. For the induced electric field strength, The speed of movement of the intelligent experimental payload chamber 4. The magnetic flux density of the magnet; Eddy currents in a magnetic field experience a Lorentz force, and the reaction force of this force is the damping force acting on the load chamber. , This is the eddy current damping force. Let be the volume of the eddy current copper plate.

[0033] The direction of the damping force is opposite to the direction of motion of the load compartment, and the magnitude of the damping force is approximately equal to the motion velocity. Proportional, that is ,in The damping coefficient, determined by the magnetic field of the magnet, the parameters of the copper plate, and the relative area, enables adaptive deceleration; that is, the faster the speed, the greater the braking force. Combining the damping force, the dynamic equation for the descent of the payload compartment is: The total mass of the payload compartment. It is the acceleration due to gravity. The equation represents the balancing tension of the counterweight components. It allows for the quantitative calculation of the changes in velocity and acceleration of the load chamber under eddy current damping over time, verifying the pre-deceleration effect and ensuring that the chamber's velocity drops to a safe threshold before entering the hydraulic buffer.

[0034] Through formula By working backward, the thickness, area, and material of the eddy current copper plate 22, as well as the magnetic field strength, quantity, and arrangement of the powerful magnets 31, can be determined to ensure that the damping force meets the pre-deceleration requirements.

[0035] The eddy current safety recovery system also includes a hydraulic buffer 23 and a spring buffer 21. A bottom support platform 1 is fixedly installed at the lower end of the tower 3. The top support platform 2 is distributed vertically to the bottom support platform 1. Both the hydraulic buffer 23 and the spring buffer 21 are installed on the bottom support platform 1. After the powerful magnet 31 and the eddy current copper plate 22 achieve non-contact adaptive pre-deceleration, the intelligent experimental load chamber 4 comes into contact with the hydraulic buffer 23 and spring buffer 21 at the bottom of the tower 3, and achieves a soft landing through multi-stage buffering to avoid rigid impact.

[0036] Furthermore, multiple sets of locking rods 15 are fixedly installed on the top surface of the intelligent experimental payload chamber 4, with locking buckles 16 at the upper ends of the locking rods 15. Multiple sets of mechanical locks 17, matching the number of locking rods 15, are fixedly installed on the bottom surface of the top support platform 2. Locking grooves 18 are formed on the bottom surface of each mechanical lock 17, and multiple sets of spring columns 19 are fixedly installed on the inner wall of the locking grooves 18. These spring columns 19 are arranged in a circular array around the center of the locking grooves 18. Distributed locking blocks 20, which are arc-shaped claw structures, are fixedly installed at the ends of the spring columns 19 closest to the center of the locking grooves 18. When the intelligent experimental payload chamber 4 rises to its initial position at the top of the tower, the locking buckles 16 at the upper ends of the locking rods 15 engage with the locking grooves 18 of the mechanical locks 17. Under the elastic pre-tightening force of the spring columns 19, the distributed locking blocks 20 grip and engage the locking buckles 16, achieving initial mechanical locking of the intelligent experimental payload chamber 4. Once the experimental conditions are ready, the control system drives the spring column 19 to retract, which in turn causes the distributed locking block 20 to release from the locking buckle 16, thus completing the unlocking and release. This ensures the safety and reliability of the experiment's start-up. At the same time, the cooperation of the spring column 19, the distributed locking block 20, the locking rod 15, and the locking buckle 16 locks the intelligent experimental load chamber 4 in the initial stage of the experiment.

[0037] Safety clamps 32 are fixedly installed on both sides of the payload chamber mounting base 12, corresponding to the low-friction linear guide rails of the tower 3. They move vertically along the Z-axis synchronously with the intelligent experimental payload chamber 4, remaining within the effective travel range of the guide rails throughout the entire movement. Braking can be triggered at any position. If the hybrid variable gravity control system and the eddy current safety recovery system fail, such as if the steel wire rope 10 breaks, the servo motor 5 goes out of control, or the magnetic powder brake 7 malfunctions, causing the intelligent experimental payload chamber 4 to fall at excessive speed, the safety clamps 32 can automatically trigger emergency braking, rigidly locking the intelligent experimental payload chamber 4 onto the guide rails of the tower 3, completely preventing the chamber from falling and avoiding rigid collisions between the chamber, experimental equipment, and the bottom of the tower. This fundamentally eliminates safety accidents and ensures the safety of personnel, equipment, and the device itself.

[0038] The onboard synchronous data acquisition system integrates high-frequency IMU, thermocouple, ammeter and other components to complete high-frequency acquisition of multi-source parameters such as triaxial acceleration, attitude, process temperature / current, etc. A high frame rate industrial camera records the visual images of the printing nozzle and melting interface. All data is written in real time to the onboard shockproof storage card in the intelligent experimental load chamber 4. The black box storage mode avoids data loss caused by recycling impact and realizes the synchronous retention of environmental parameters and process parameters.

[0039] Example 2 This embodiment focuses on the eddy current safety recovery system of a vacuum microgravity 3D printing simulation test platform. It reverse-engineers the parameters for the eddy current copper plate 22 and the powerful magnet 31 to ensure that the pre-deceleration effect meets design requirements. Intelligent Experimental Payload Chamber 4 Total Mass =500kg, after the experiment, based on the initial falling speed =2.0m / s entering the braking zone at the bottom of tower 3, requiring the cabin's final velocity to decrease to after eddy current damping pre-deceleration. ≤0.5m / s, providing a safe input condition for subsequent hydraulic buffering; Known constraints: Effective travel of the braking zone =1.0m, counterweight to balance the tension =4000N (counteracting 80% of the cabin's own weight), gravitational acceleration .

[0040] Based on the linear relationship between eddy current damping force and velocity under low-speed conditions Combining the equations of motion of the payload compartment: Substituting the known parameters, the net driving force of the cabin is: Convert the equations of motion into displacement form. Integrating, we obtain the velocity-displacement relationship: Substitution =2.0m / s =0.5m / s =1.0m =500kg =900N, solve for the minimum damping coefficient. That is, the damping force needs to be guaranteed to be within At a speed of 2.0 m / s, the N value is not less than 2400 N. The selection of parameters for eddy current copper plate 22 is based on the engineering calculation formula for eddy current damping coefficient: The conductivity of the copper plate, For the thickness of the copper plate, The working magnetic flux density of the magnet. This represents the effective relative area between the magnet and the copper plate. This refers to the air gap between the magnet and the copper plate.

[0041] Selection Calculation: 1) Material selection: High conductivity copper is selected. =5.96×107S / m, maximizing eddy current generation efficiency; 2) Air gap design: To avoid friction, an air gap is set. =5mm=0.005m; Thickness and area are used to inversely determine the working magnetic induction intensity of the magnet. Substitute ,have to: Based on the structural layout, the thickness of the eddy current copper plate 22 was determined. =10mm=0.01m, effective working area =0.07m 2 It is laid along the Z-axis at the bottom braking area of ​​the tower 3, and is arranged directly opposite to the powerful magnet 31 on the outer wall of the intelligent experimental payload cabin 4.

[0042] For the selection of powerful magnets, parameter 31 is recommended. The N52 type neodymium iron boron magnet is chosen, with a surface magnetic induction intensity of [missing information]. This satisfies the above calculation requirements; 1) Quantity and size deduction: To match the effective area of ​​the copper plate, S=0.07m² 2 Magnets with individual dimensions of 100mm × 50mm × 20mm are selected, with an effective area of ​​0.005m² per magnet. 2 Therefore, it is equipped with 14 strong magnets 31; 2) Arrangement design: 14 magnets are arranged in two columns vertically along the Z-axis on the outer wall of the intelligent experimental load chamber 4, with a column spacing of 50mm, 7 magnets per column, and a spacing of 10mm between adjacent magnets, to ensure that the effective relative area of ​​the magnets and the eddy current copper plate 22 is fully covered, with no magnetic field blind spots, and to maximize the output of damping force.

[0043] After selecting the parameters, substitute them into the equation of motion for simulation verification: When the intelligent experimental payload chamber 4 When entering the braking zone at a speed of 2.0 m / s, the initial damping force is: The force is much greater than the net driving force of 900N, causing the cabin to decelerate rapidly. After traveling through the 1.0m braking zone, the final velocity of the cabin =0.42m / s, which meets the design requirement of ≤0.5m / s, and realizes non-contact adaptive pre-deceleration; At the same time, through the Joule heat formula Calculations show that the maximum temperature rise of the copper plate does not exceed 30°C, eliminating the need for additional heat dissipation design and ensuring structural reliability.

[0044] Example 3 Validation of 3D printing process for molten metal under simulated lunar low-gravity vacuum environment This embodiment utilizes the aforementioned 3D printing simulation test platform under vacuum microgravity to simulate the high vacuum and 0.16g low gravity composite environment on the lunar surface in a ground laboratory, and conducts metal melting 3D printing experiments to solve practical engineering problems such as abnormal melt flow, poor molding quality, and difficulty in determining process parameters during in-situ manufacturing on the moon. Experimental conditions settings: The intelligent experimental payload chamber uses an external molecular pump assembly connected to a vacuum valve to pump the vacuum level inside the chamber to 1×10⁻³Pa, simulating the high vacuum environment of the moon. The hybrid variable gravity control system offsets 84% ​​of the cabin's own weight through coarse adjustment of the counterweight, and works in conjunction with the magnetic powder brake to precisely output traction force, so that the equivalent gravitational acceleration of the cabin is stabilized at 0.16g±0.01g. Printing material: aluminum-silicon alloy wire, 1.6mm in diameter; Process objective: To mold a standard mechanical specimen measuring 20mm × 20mm × 10mm, free from cracks and obvious spheroidization, with a density ≥ 95%; Before the experiment, the intelligent experimental payload chamber was fixed by a top mechanical lock, and the chamber was evacuated and preheated. After unlocking, the hybrid variable gravity control system drives the payload compartment to descend at a constant speed, maintaining a low gravity state of 0.16g. The 3D printing extrusion mechanism and micro melting furnace inside the cabin are started, the onboard synchronous data acquisition system collects temperature, current, triaxial acceleration and attitude data in real time, and the high-speed camera records the melt forming process. After printing is completed, the payload compartment continues to fall, and soft recovery is achieved through non-contact pre-deceleration of the eddy current copper plate and multi-stage buffering of hydraulic and spring systems. Based on this embodiment, using the 3D printing simulation test platform under vacuum microgravity environment, the known fixed parameters include: Total mass of the payload compartment: M=500kg Target lunar gravity: 0.16g Counterweight balancing force: offsets 84% ​​of its own weight Braking travel: 1.0m Braking speed: 2.0 m / s Target velocity before buffering: ≤0.5m / s Vacuum degree: 1×10 -3 Pa; To quantitatively verify the adaptability of this platform to the 3D printing process and the stability of system operation in a simulated lunar low-gravity vacuum environment on Earth, this embodiment conducts field measurements and comparative analyses of key indicators such as gravity simulation accuracy, vacuum environment parameters, printing quality, cabin movement stability, safe recovery performance, and data acquisition reliability. A conventional Earth-based atmospheric gravity environment is used as a control group. The test results are shown in the table below: As shown in the table above, compared to the conventional 1g atmospheric gravity environment on Earth, the 3D printing experiment using this platform to simulate the 0.16g low gravity and high vacuum composite environment of the moon can accurately control the equivalent gravitational acceleration at 0.16g ± 0.01g, and the vacuum degree inside the cabin can be stably reached 1×10⁻³Pa, effectively meeting the requirements of lunar environment simulation. The density of the printed sample increased from 92.0% to 95.2%, the dimensional error decreased from ±0.30mm to ±0.05mm, and the surface roughness was optimized from 12.0μm to 6.5μm, significantly improving the molding quality and dimensional accuracy. The cabin motion acceleration fluctuation was controlled within ±0.015m / s², and the velocity before recovery decreased to 0.42m / s, meeting the safety buffer threshold requirements. All indicators verify that this platform has reliable practicality and engineering application value.

[0045] The technical means disclosed in this invention are not limited to those described above, but also include technical solutions composed of equivalent substitutions of the above technical features. Matters not covered in this invention are common knowledge to those skilled in the art.

Claims

1. A 3D printing simulation test platform under vacuum microgravity environment, characterized in that: The system includes a guide frame system, an intelligent experimental payload chamber (4), and a hybrid variable gravity control system. The guide frame system is based on a vertically erected tower (3). A top support platform (2) is fixedly installed on the top of the tower (3), and the bottom of the tower (3) is fixed on a bottom support platform (1). Low-friction linear guides are mounted on the frame of the tower (3). The intelligent experimental payload chamber (4) is adapted to be installed on the linear guides through a payload chamber mounting seat (12). The hybrid variable gravity control system is integrated on the top support platform (2). The intelligent experimental payload chamber (4) is equipped with a 3D printing extrusion mechanism and a micro melting furnace. The 3D printing extrusion mechanism is located in the working area in the middle of the chamber, and the micro melting furnace is located on the side of the printing extrusion mechanism and arranged in coordination with it. A high-frequency IMU is fixed at the center of the top of the chamber to collect attitude and acceleration signals. Thermocouples are attached to the printing nozzle and the outer wall of the melting furnace to detect the process temperature. An ammeter is connected in series to the power supply circuit for printing and melting to monitor the working current. A high-speed camera is installed at the center of the top of the intelligent experimental payload chamber (4).

2. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: The outer side of the intelligent experimental load chamber (4) is provided with an outer baffle (11), and a pulley mounting groove (13) is opened on the load chamber mounting base (12), and a pulley (14) is installed in the groove, so that the intelligent experimental load chamber (4) can only move vertically along the Z axis within the tower (3) due to the restriction of the guide rail and the pulley (14); a vacuum valve (31) is provided on the outer wall of the outer baffle (11), and an external vacuum pumping device is connected to quickly remove the air in the chamber to construct a vacuum experimental environment.

3. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: The hybrid variable gravity control system is integrated on the top support platform (2). The hybrid variable gravity control system includes a servo motor (5), an electromagnetic braking unit (6), a magnetic powder brake (7), a clutch (8), and a fixed pulley (9). The servo motor (5), electromagnetic braking unit (6), magnetic powder brake (7), clutch (8), and fixed pulley (9) are installed in series on the top support platform (2) in a coaxial manner. One end of the steel wire rope (10) is fixedly connected to the top of the intelligent experimental load chamber (4), and the other end passes around the fixed pulley (9) and is fixedly connected to the counterweight assembly.

4. The 3D printing simulation test platform under vacuum microgravity environment according to claim 3, characterized in that: The counterweight assembly includes a fixed groove (24), which is fixedly installed along the Z-axis on the side of the tower (3) away from the intelligent experimental payload chamber (4). A counterweight box (25) and an upper connecting bracket (28) are slidably installed inside the fixed groove (24). A connecting ear plate (26) is fixedly installed on the upper connecting bracket (28), and a counterweight guide rod (27) is fixedly installed between the connecting ear plate (26) and the counterweight box (25). Multiple sets of counterweight blocks (30) are sleeved on the counterweight guide rod (27), and the counterweight blocks (30) are located in the internal cavity of the counterweight box (25). A movable pulley (29) is rotatably installed inside the upper connecting bracket (28) through a rotating shaft. The end of the steel wire rope (10) away from the intelligent experimental payload chamber (4) is connected and fixed to the movable pulley (29). The power is transmitted by the movable pulley (29) through the connecting ear plate (26) to drive the counterweight assembly to move up and down synchronously along the fixed groove (24).

5. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: The eddy current safety recovery system includes an eddy current copper plate (22) and a powerful magnet (31). The powerful magnet (31) is fixedly installed on the outer wall of the intelligent experimental payload chamber (4) as a mover, and the eddy current copper plate (22) is fixedly laid in the braking area at the bottom of the tower (3) along the Z-axis direction as a stator, corresponding to the position of the powerful magnet (31).

6. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: It also includes an eddy current safety recovery system, which further includes a hydraulic buffer (23) and a spring buffer (21), both of which are mounted on the bottom support platform (1).

7. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: The top surface of the intelligent experimental payload chamber (4) is fixedly installed with multiple sets of locking rods (15), and the upper end of the locking rods (15) is provided with locking buckles (16); the bottom surface of the top support platform (2) is fixedly installed with multiple sets of mechanical locks (17) matching the number of locking rods (15), the bottom surface of the mechanical locks (17) is provided with locking grooves (18), the inner wall of the locking grooves (18) is fixedly installed with multiple sets of spring columns (19), the multiple sets of spring columns (19) are arranged in a circular array with the center of the locking grooves (18) as the center, and the end of the multiple sets of spring columns (19) near the center of the locking grooves (18) is fixedly installed with a distributed card block (20), the distributed card block (20) is an arc-shaped claw structure.

8. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: Safety clamps (32) are fixedly installed on both the left and right sides of the load chamber mounting base (12), and are arranged corresponding to the low-friction linear guide rail of the tower (3).

9. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that: It also includes an onboard synchronous data acquisition system, which includes a high-frequency IMU, thermocouples and ammeters to complete the high-frequency acquisition of triaxial acceleration, attitude and process temperature / current multi-source parameters. A high-speed camera records the visual images of the printing nozzle and melting interface. All data is written in real time to the onboard anti-vibration storage card in the intelligent experimental load chamber (4).

10. The 3D printing simulation test platform under vacuum microgravity environment according to claim 1, characterized in that, When the powerful magnet moves relative to the eddy current copper plate with the intelligent experimental payload chamber, the magnetic flux passing through the eddy current copper plate changes, generating an induced electromotive force. The induced electromotive force satisfies: in, To induce electromotive force. The magnetic flux passing through the copper plate. The magnetic flux density of the magnet is . For the area of ​​a copper plate element, The differential symbol, For a small change in time, the faster the magnet moves and the stronger the magnetic field, the greater the induced electromotive force generated within the copper plate. This provides the driving force for the generation of eddy currents. The induced electromotive force drives the generation of eddy currents within the copper plate, and the current density satisfies: The eddy current density, The conductivity of the copper plate is given by [insert value here]. For the induced electric field strength, The speed of movement of the intelligent experimental payload chamber (4), The magnetic flux density of the magnet; Eddy currents in a magnetic field experience a Lorentz force, and the reaction force of this force is the damping force acting on the load chamber. , This is the eddy current damping force. Let V be the volume of the eddy current copper plate. The direction of the damping force is opposite to the direction of motion of the load compartment, and the magnitude of the damping force is approximately equal to the motion velocity. Proportional, that is ,in The damping coefficient, determined by the magnetic field of the magnet, the parameters of the copper plate, and the relative area, enables adaptive deceleration; that is, the faster the speed, the greater the braking force. Combining the damping force, the dynamic equation for the descent of the payload compartment is: The total mass of the payload compartment. It is the acceleration due to gravity. The equation is used to calculate the changes in velocity and acceleration of the load chamber under eddy current damping as a function of the counterweight components, verify the pre-deceleration effect, and ensure that the speed of the chamber drops to a safe threshold before entering the hydraulic buffer. Through formula By working backward, the thickness, area, and material of the eddy current copper plate (22), as well as the magnetic field strength, quantity, and arrangement of the powerful magnets (31), are determined to ensure that the damping force meets the pre-deceleration requirements.

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