A controllable superconducting magnetic field generating device for spatial electromagnetic manipulation

Abstract

A controllable superconducting magnetic field generating device for spatial electromagnetic manipulation, comprising a moving platform, a control system and a superconducting coil assembly. The superconducting coil assembly is used to generate an electromagnetic field. The superconducting coil assembly is installed on the moving platform, supported by the moving platform and realizes three-degree-of-freedom motion control of the superconducting coil assembly through the moving platform. The superconducting coil assembly includes a vacuum dewar cylinder, a superconducting coil, a coil skeleton, a liquid nitrogen cavity and coil leads. By using high-temperature superconducting materials to wind the electromagnetic coils in the superconducting coil assembly, an electromagnetic field that is ten times or even dozens of times larger can be generated under the same size and number of turns of a normal conducting material coil, which can significantly improve the effect of spatial electromagnetic manipulation. The wall of the vacuum dewar cylinder is coated with a vacuum insulation layer, and the inside thereof is a liquid nitrogen cavity filled with liquid nitrogen. The superconducting coil and the coil skeleton are placed in the liquid nitrogen cavity, which can effectively reduce heat exchange while meeting the low-temperature environment of the high-temperature superconducting material, and improve the stability and durability of the operation of the superconducting coil.

Description

Technical Field

[0001] The present invention belongs to the technical field of space electromagnetic control and its ground test simulation, and particularly relates to a controllable superconducting magnetic field generating device for space electromagnetic control. Background Art

[0002] Currently, the number of orbital debris, including defunct satellites, is increasing, posing a great threat to human space activities and the safe operation of on-orbit spacecraft. Therefore, it is of great significance to accelerate the research on on-orbit control technologies for tasks such as capture, repair, and deorbiting. To successfully carry out on-orbit control tasks such as approaching and capturing, it is necessary to first control the position / attitude of the defunct satellite to achieve the desired relative state. However, traditional contact control means have a short action distance, high control difficulty, and high safety risks. In recent years, non-contact on-orbit control means have received extensive attention.

[0003] Space electromagnetic control is a representative non-contact on-orbit control method. It uses on-board electromagnetic devices to generate controllable electromagnetic fields, and generates non-contact field forces through the interaction between the electromagnetic fields and the target or between the electromagnetic fields, thereby achieving the control of relative position / attitude. Since the electromagnetic field strength decays inversely with the fourth power of the distance, to obtain an ideal non-contact control effect, the spacecraft needs to be able to generate a large-intensity electromagnetic field. For traditional electromagnetic coils based on normal-conducting materials, only the coil diameter and the number of coil turns can be increased, resulting in a large volume and heavy mass of the magnetic field generating device, posing a huge challenge to the overall design of the spacecraft.

[0004] The booming development of superconducting technology has brought new hope for space electromagnetic control. By using superconducting coil technology, an electromagnetic field with a strength dozens of times can be generated under the premise of the same coil diameter and number of turns, thus greatly increasing the magnitude of the inter-satellite electromagnetic force / torque and significantly improving the non-contact control effect. In addition, to meet the electromagnetic control requirements under different targets and different motion states, the electromagnetic field strength needs to be flexibly controllable and have the ability to maneuver the relative position / attitude with the target. Currently, in the experimental systems for electromagnetic docking and electromagnetic despin carried out on the ground, superconducting technology has not been verified and applied, and some experimental schemes using permanent magnets cannot achieve flexible control of the magnetic field, and there are limitations in further analyzing the electromagnetic control mechanism and characteristics. Therefore, designing a device that can achieve the generation of a controllable large-field-strength electromagnetic field and the simulation of relative motion is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To solve the problems existing in the prior art, the present invention provides a controllable superconducting magnetic field generating device for space electromagnetic control, which uses high-temperature superconducting technology to generate a controllable large-field-strength electromagnetic field.

[0006] To achieve the above technical objectives, the specific technical solutions adopted by the present invention are as follows:

[0007] A controllable superconducting magnetic field generating device for space electromagnetic manipulation, comprising a moving platform, a control system and a superconducting coil assembly. The superconducting coil assembly is used to generate an electromagnetic field under the control of the control system. The superconducting coil assembly is installed on the moving platform, supported by the moving platform and its movement is controlled by the moving platform.

[0008] As a preferred solution, the moving platform in the present invention includes a support chassis, a servo guide rail, a turntable bracket, a servo turntable and a mounting base. The superconducting coil assembly is installed on the mounting base. The mounting base is fixed on the servo turntable, and the rotation control of the superconducting coil assembly is realized by the servo turntable. The servo turntable is installed above the servo guide rail through the turntable bracket, and the turntable bracket can move along the guide rail direction of the servo guide rail, thereby driving the superconducting coil assembly to realize linear motion control. The servo guide rail is installed on the support chassis and supported by the support chassis.

[0009] As a preferred solution, the superconducting coil assembly in the present invention includes a vacuum dewar cylinder, a superconducting coil, a coil skeleton, a liquid nitrogen cavity and coil leads. The liquid nitrogen cavity filled with liquid nitrogen is inside the vacuum dewar cylinder. The superconducting coil and the coil skeleton are placed in the liquid nitrogen cavity, and the superconducting coil is wound around the coil skeleton. A lead socket is provided on the vacuum dewar cylinder. The inner and outer joints of the superconducting coil are connected to the coil leads, and the coil leads are powered by a 110A constant current source at the lead socket, so that the superconducting coil generates a magnetic field. The superconducting coil is placed in the liquid nitrogen cavity, and the low temperature of the superconducting coil is maintained by filling liquid nitrogen. Further, a vacuum insulation layer is coated on the inner side wall of the vacuum dewar cylinder, which can effectively reduce heat exchange and improve the refrigeration effect.

[0010] A liquid nitrogen filling port for filling liquid nitrogen into the liquid nitrogen cavity is provided on the vacuum dewar cylinder of the present invention. Liquid nitrogen is injected into the liquid nitrogen cavity through the liquid nitrogen filling port by using a self-pressurizing liquid nitrogen tank (working pressure 0.09 Mpa). The bottom center of the vacuum dewar cylinder is fixedly connected with the mounting base. To avoid magnetic field interference caused by other metal components, the surface of the mounting base needs to be insulated. Further, a temperature sensor is also provided in the liquid nitrogen cavity. Specifically, the temperature sensor is a PT100 sensor, and there are 2 in total, which are respectively placed at the top of the superconducting coil and the intersection of the liquid nitrogen cavity and the liquid nitrogen filling port. The liquid level position of the liquid nitrogen is determined according to the temperature of the PT100 sensor. When the temperature is higher than 80K, liquid nitrogen needs to be replenished to ensure that the superconducting coil is always immersed in liquid nitrogen during operation.

[0011] As a preferred solution, the length of the servo guide rail in the present invention is 1100 mm, and the positioning accuracy in the guide rail direction is 0.1 mm. The stroke of the servo turntable is -180° to +180°, and the rotation accuracy is 0.1°.

[0012] As a preferred solution, the superconducting coil of the present invention is made of high-temperature superconducting tape, and its main component is Bi-2223 / Ag. The superconducting coil is wound in a single-wire single-pancake manner, with an inner diameter of the coil being 1 m, the wire consumption being 800 m, and the critical current of the superconducting coil being 85 A (77 K, self-field).

[0013] As a preferred solution, the control system is used for superconducting magnetic field control and motion control of the superconducting coil device. The control system includes a superconducting magnetic field control module and a servo control module.

[0014] The superconducting magnetic field control module includes a coil current control unit, a coil temperature monitoring unit, and a coil voltage monitoring unit. The coil current control unit is realized by connecting the coil lead through a constant current source. The coil temperature monitoring unit is realized by two-channel AD acquisition cards, and the two-channel AD acquisition cards are respectively connected to one temperature sensor; the liquid nitrogen liquid level position is determined according to the temperature of the PT100 sensor, and when the temperature is higher than 80 K, liquid nitrogen needs to be replenished to ensure that the superconducting coil is always immersed in liquid nitrogen. The coil voltage monitoring unit includes one-channel AD acquisition card, which is realized by connecting the coil lead. By collecting the voltage across the superconducting coil, it is judged whether the superconducting coil is in the superconducting state to prevent the superconducting coil from burning out during quenching.

[0015] The motion control is realized through the servo control module. The servo control module is respectively connected to the servo guide rail and the servo turntable to realize linear motion control and azimuth rotation control.

[0016] The present invention can be applied to various ground test systems for space electromagnetic manipulation, including but not limited to ground test systems for electromagnetic docking and electromagnetic despin. The controllable superconducting magnetic field generating device for space electromagnetic manipulation is used to generate the required controllable large magnetic field strength electromagnetic field in the ground test system for space electromagnetic manipulation.

[0017] Compared with the existing methods, the advantages and beneficial effects of the present invention include:

[0018] The present invention provides a specific solution for a controllable superconducting magnetic field generating device for space electromagnetic manipulation. The electromagnetic coil wound with high-temperature superconducting materials can generate an electromagnetic field dozens of times larger than that of a normal-conducting material coil under the same size and number of turns, which can significantly improve the space electromagnetic manipulation effect. The designed vacuum dewar structure and liquid nitrogen refrigeration scheme can effectively reduce heat exchange while meeting the low-temperature environment of high-temperature superconducting materials, and improve the stability and durability of the superconducting coil operation. The servo guide rail and the servo turntable can realize three-degree-of-freedom motion control of the superconducting coil device, providing a more effective magnetic field generating device for carrying out ground tests of electromagnetic manipulation, analyzing the mechanism and characteristics of electromagnetic manipulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1It is a schematic structural diagram of a controllable superconducting magnetic field generating device for spatial electromagnetic manipulation in an embodiment of the present invention.

[0020] Figure 2 It is a top view of a controllable superconducting magnetic field generating device for spatial electromagnetic manipulation in an embodiment of the present invention.

[0021] Figure 3 It is a schematic structural diagram of a superconducting coil device in an embodiment of the present invention.

[0022] Figure 4 It is a diagram of the winding method of a superconducting coil in an embodiment of the present invention.

[0023] Figure 5 It is a control system diagram of a controllable superconducting magnetic field generating device for spatial electromagnetic manipulation in an embodiment of the present invention.

[0024] Figure 6 It is a schematic structural diagram of applying the present invention to a ground test system for electromagnetic-vortex cancellation.

[0025] Figures 1 to 5 The reference numeral descriptions in [Figure number] are as follows: 1 is a support chassis, 2 is a control box, 3 is a control line, 4 is a servo guide rail, 5 is a turntable support, 6 is a servo turntable, 7 is a mounting base, 8 is a superconducting coil assembly, 9 is a lead socket, 10 is a liquid nitrogen filling port, 11 is a vacuum dewar cylinder, 12 is a superconducting coil, 13 is a coil skeleton, 14 is a vacuum insulation layer, 15 is a liquid nitrogen chamber, 16 is a coil lead, and 17 is a temperature sensor.

[0026] Figure 6 The reference numeral descriptions in [Figure number] are as follows: 601 is a rotating platform support, 602 is a jet support, 603 is a left starting nozzle, 604 is a right starting nozzle, 605 is a wind impeller, 606 is a laser tachometer, 607 is a horizontal fine adjustment block, 608 is a dynamic seal air release port, 609 is a high-precision air bearing, 610 is a marble table, 611 is a positioning cone, 612 is a sealing groove, 613 is a gas extraction hole, 614 is a cone sleeve locking mechanism, 615 is a spatial target simulation part, 616 is a vacuum cover body, 617 is a tower-type multi-layer cover plate, and 618 is a self-locking bolt. Detailed implementation manners

[0027] In order to make the technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] Embodiment 1:

[0029] Refer to Figure 1 and Figure 2, this embodiment provides a controllable superconducting magnetic field generating device for space electromagnetic manipulation, including a support chassis 1, a control box 2, a control line 3, a servo guide rail 4, a turntable bracket 5, a servo turntable 6, a mounting base 7, a superconducting coil assembly 8, a lead socket 9, and a liquid nitrogen filling port 10.

[0030] As Figure 1 shown, the superconducting coil assembly 8 in this embodiment is installed on the mounting base 7. The bottom center of the superconducting coil assembly 8 is fixedly connected to the mounting base 7. To avoid magnetic field interference caused by other metal components, the surface of the mounting base 7 needs to be insulated. The mounting base 7 is fixed on the servo turntable 6, and the rotation control of the superconducting coil assembly 8 is realized by the servo turntable 6. The servo turntable 6 is installed above the servo guide rail 4 through the turntable bracket 5, and the turntable bracket 5 can move along the guide rail direction of the servo guide rail 4, thereby driving the superconducting coil assembly 8 to realize linear motion control. The servo guide rail 4 is installed on the support chassis 1 and is supported by the support chassis 1.

[0031] In this embodiment, the length of the servo guide rail 4 is 1100 mm, and the positioning accuracy in the guide rail direction is 0.1 mm. The stroke of the servo turntable 6 is -180° to +180°, and the rotation accuracy is 0.1°. The mounting base 7 is above the servo turntable 6. Through the servo turntable 6, the superconducting coil device 8 can realize azimuth rotation within -180° to +180° with an accuracy of 0.1°. The servo turntable 6 is installed at the center of the turntable bracket 5. The turntable bracket 5 is above the servo guide rail 4 and can move linearly along the guide rail direction, thereby driving the superconducting coil device 8 to realize position movement within a range of 1100 mm with a positioning accuracy of 0.1 mm.

[0032] The superconducting coil assembly 8 is the core component of the controllable superconducting magnetic field generating device. Based on high-temperature superconducting materials, the electromagnetic coil can pass a larger current, so it can generate an electromagnetic field with a much larger field strength compared to traditional normal-conducting coils.

[0033] Referring to Figure 3 , the superconducting coil assembly 8 includes a vacuum dewar cylinder 11, a superconducting coil 12, a coil skeleton 13, a liquid nitrogen cavity 15, and coil leads 16. To achieve the low-temperature operating environment of the high-temperature superconducting coil, liquid nitrogen is used for refrigeration. The liquid nitrogen cavity 15 filled with liquid nitrogen is inside the vacuum dewar cylinder 11. The superconducting coil 12 and the coil skeleton 13 are placed in the liquid nitrogen cavity 15, and the superconducting coil 12 is wound around the coil skeleton 13. The superconducting coil 12 is made of first-generation high-temperature superconducting tape, with the main component being Bi-2223 / Ag, and is wound in a single-wire single-pancake manner. As Figure 4 shown, the inner diameter of the coil is 1 m, and the wire consumption is 800 m.

[0034] The vacuum dewar cylinder 11 is provided with a lead socket 9, which is used to connect a constant current source for power supply. The inner and outer joints of the superconducting coil 12 are connected to the coil leads 16, and the coil leads 16 are powered by a 110A constant current source at the lead socket 9, so as to generate a magnetic field in the superconducting coil. The superconducting coil 12 is placed in the liquid nitrogen cavity 15, and the low temperature of the superconducting coil is maintained by filling liquid nitrogen. The inner side wall of the vacuum dewar cylinder 11 is coated with a vacuum insulation layer 14, which can effectively reduce heat exchange and improve the refrigeration effect. The vacuum dewar cylinder 11 has a hollow tube wall structure, and the sealed vacuum degree ≤ 2×10 -4 Pa, and the heat conductivity of the vacuum interlayer is 1.5×10-4W / (m·K). Therefore, heat exchange can be effectively reduced, ensuring the long-term operation of the superconducting coil to meet the requirements of space target electromagnetic control experiments.

[0035] The vacuum dewar cylinder 11 in the present invention is provided with a liquid nitrogen filling port 10 for filling liquid nitrogen into the liquid nitrogen cavity. The liquid nitrogen filling port is used to connect a self-pressurizing liquid nitrogen tank to fill liquid nitrogen to achieve a low-temperature working environment for the superconducting coil. The liquid nitrogen is injected into the liquid nitrogen cavity through the liquid nitrogen filling port 10 by using a self-pressurizing liquid nitrogen tank (working pressure 0.09Mpa). The bottom center of the vacuum dewar cylinder 11 is fixedly connected with an installation base 7. To avoid magnetic field interference caused by other metal components, the surface of the installation base 7 needs to be insulated.

[0036] The temperature sensors 17 arranged in the liquid nitrogen cavity 15 are PT100 sensors, with a total of 2, which are respectively placed at the top of the superconducting coil 12 and the intersection of the liquid nitrogen cavity 15 and the liquid nitrogen filling port 10. The liquid level position of the liquid nitrogen is determined according to the temperature of the PT100 sensors. When the temperature is higher than 80K, liquid nitrogen needs to be replenished to ensure that the superconducting coil is always immersed in the liquid nitrogen.

[0037] The superconducting coil 12 in the present invention is made of first-generation high-temperature superconducting tapes, with the main component being Bi-2223 / Ag. It is wound in a single-wire single-pancake manner, with an inner diameter of 1m for the coil and a wire usage of 800m. The critical current of the superconducting coil 12 is 85A (77K, self-field).

[0038] Refer to Figure 1 , the control box 2 is placed on the support chassis 1, and the control system is used for the superconducting magnetic field control and motion control of the superconducting coil device. The control box 2 is connected to the motor of the servo guide rail 2, the control box 2 is connected to the motor of the servo turntable 6, and the control box 2 is connected to the coil leads 16 through control lines respectively. The control box can achieve the azimuth rotation control and linear motion control of the superconducting coil device 8 by controlling the motors of the servo guide rail 2 and the servo turntable 6, and the control box 2 realizes the control of the superconducting magnetic field by controlling the working power supply of the superconducting coil.

[0039] The control system of the controllable superconducting magnetic field generating device is realized by connecting the upper computer to the control box 2. The control system includes a superconducting magnetic field control module and a servo control module, as Figure 5 shown.

[0040] Referring to Figure 5 , the superconducting magnetic field control module includes a coil current control unit, a coil temperature monitoring unit and a coil voltage monitoring unit.

[0041] The coil current control unit is realized by connecting the coil lead 16 through a constant current source. The constant current source uses an Itech IT6723C DC power supply with a power of 850W and a maximum output current of 110A.

[0042] The coil temperature monitoring unit is realized by a 2-channel AD acquisition card. The 2-channel AD acquisition card is respectively connected to 1 temperature sensor 16; the temperature sensor 16 uses a PT100 sensor, a total of 2, which are respectively placed at the top of the superconducting coil 12 and the intersection of the liquid nitrogen cavity 14 and the liquid nitrogen filling port 10. The AD acquisition card collects the voltage of the PT100 sensor, thereby calculating the resistance of the PT100 sensor, determining the temperature of the PT100 sensor according to the relationship between the resistance of the PT100 sensor and the temperature, and further determining the liquid level position of the liquid nitrogen. When the temperature is higher than 80K, liquid nitrogen needs to be replenished to ensure that the superconducting coil 12 is always immersed in liquid nitrogen.

[0043] The coil voltage monitoring unit uses another 1-channel AD acquisition card to connect to the coil lead 16, and judges whether the superconducting coil 12 is in a superconducting state by collecting the voltage across the superconducting coil 12, preventing the superconducting coil 12 from burning out during quenching.

[0044] The motion control is realized through the servo control module. The servo control module is respectively connected to the servo guide rail 4 and the servo turntable 6 to realize linear motion control and azimuth rotation control.

[0045] The construction method of a controllable superconducting magnetic field generating device for space electromagnetic manipulation in this embodiment is as follows:

[0046] Step 1: Level the support chassis 1 equipped with the superconducting coil device 8 using a spirit level to ensure the stability of the superconducting coil device 8 during movement.

[0047] Step 2: Connect the self-pressurizing liquid nitrogen tank filled with liquid nitrogen to the liquid nitrogen filling port 10 using a liquid nitrogen delivery pipe. Observe the pressure gauge of the self-pressurizing liquid nitrogen tank. When the pressure ≥ 0.05 Mpa, open the liquid outlet valve of the self-pressurizing liquid nitrogen tank to continuously fill until the liquid nitrogen cavity 14 is full of liquid nitrogen.

[0048] Step 3: Connect the circuit and power on the control box 2 and the host computer. Monitor the temperature of the PT100 temperature sensor 16. When it stabilizes at around 77K, check whether the resistance of the superconducting coil has decreased to the order of a few ohms, and monitor the voltage of the superconducting coil 12 to determine whether the superconducting coil 12 is in the superconducting state.

[0049] Step 4: According to the requirements of the experimental design, control the servo guide rail 4 and the servo turntable 6 to move the superconducting coil device 8 to the desired relative position / attitude; supply power to the superconducting coil 12 through a 110A constant current source, and slowly adjust the current source to the desired current magnitude; use a magnetic field measurement device to measure the magnetic field strength at the desired position near the coil.

[0050] Step 5: Maintain the superconducting magnetic field strength and direction, and perform a ground experiment for space electromagnetic manipulation. During the process, it is necessary to monitor the coil temperature and coil quench in real time, and replenish liquid nitrogen in time to ensure the normal operation of the system.

[0051] Embodiment 2:

[0052] The present invention can be applied to various ground experiment systems for space electromagnetic manipulation. As Figure 6 shown, this embodiment provides a ground experiment system for space electromagnetic manipulation, specifically a ground experiment system for simulating the electromagnetic-vortex cancellation of a space target, which utilizes the controllable superconducting magnetic field generating device for space electromagnetic manipulation proposed by the present invention to generate the controllable electromagnetic field required for the experiment. As Figure 6 shown, it includes a space target simulation device and a controllable superconducting magnetic field generating device for space electromagnetic manipulation. The structure, principle, and construction method of the controllable superconducting magnetic field generating device for space electromagnetic manipulation have been described in detail in Embodiment 1 and will not be elaborated here. In the ground experiment system for simulating the electromagnetic-vortex cancellation of a space target shown in this embodiment, the controllable superconducting magnetic field generating device for space electromagnetic manipulation is arranged on one side of the space target simulation device, where the controllable superconducting magnetic field generating device for space electromagnetic manipulation simulates a satellite, and the space target simulation device simulates another satellite. The relative movement of the two satellites is simulated through the servo guide rail and the servo turntable in the controllable superconducting magnetic field generating device for space electromagnetic manipulation.

[0053] The space target simulation device includes a rotating platform bracket 601, a jet bracket 602, 603 is the left air nozzle for starting rotation, 604 is the right air nozzle for starting rotation, 605 is the wind impeller, 606 is the laser tachometer, 607 is the horizontal fine-tuning block, 608 is the dynamic seal air release port, 609 is the high-precision air bearing, 610 is the marble table, 611 is the positioning cone, 612 is the seal groove, 613 is the air extraction hole, 614 is the cone sleeve locking mechanism, 615 is the space target simulation part, 616 is the vacuum cover, 617 is the tower-shaped multi-layer cover plate, and 618 is the self-locking bolt.

[0054] The space target simulator 615 is fixedly connected to the positioning cone 611 along the axis. The positioning cone 611 is vertically inserted into the cone sleeve of the high-precision air bearing 609, and the vertical fixation is achieved through the cone sleeve locking mechanism 614. The high-precision air bearing 609 is installed in the center of the marble table 610. The marble table 610 is located above the rotary platform bracket 601, and the level of the marble table is adjusted by four horizontal fine-tuning blocks 607 in between. The wind impeller 605 is installed at the bottom center of the high-precision air bearing 609. The left starting air nozzle 603 and the right starting air nozzle 604 are parallelly installed on the jet bracket 602, and the jet ports are aligned with the blades of the wind impeller 605. The laser tachometer 606 is installed at an appropriate position on the rotary platform bracket 601, and is aligned with the black and white graduation marks on the blades of the wind impeller 605. When the high-precision air bearing 609 drives the space target simulator 615 to rotate, the real-time rotation speed of the space target simulator 615 can be measured by using the laser tachometer 606.

[0055] The space target simulator 615 is arranged in a vacuum container. The vacuum container includes a vacuum cover 616 and a tower-shaped multi-layer cover plate 617. The top surface of the vacuum cover 616 is sealed by the tower-shaped multi-layer cover plate 617, and the bottom of the vacuum cover 616 is sealed and fixed on the marble table 610. The tower-shaped multi-layer cover plate 617 includes multiple cover plates stacked in a tower shape. The multiple cover plates are fastened together by the self-locking bolts 618 in the center. The bottom of the vacuum cover 19 is placed in the corresponding sealing groove 15 opened on the marble table 13, and an EPDM rubber sealing strip is placed in the sealing groove 15. Four air extraction holes 613 are opened on the marble platform 610. The vacuum pump evacuates the space inside the vacuum cover through the four air extraction holes 613, and a sealed space is naturally formed during the evacuation. A dynamic seal air release port 608 is arranged between the high-precision air bearing 609 and the marble table 610. After the high-precision air bearing 609 is ventilated, air is discharged through the dynamic seal air release port 608 to minimize the air entering the space inside the vacuum cover.

[0056] Both the vacuum cover 616 and the tower-shaped multi-layer cover plate 617 are made of 10 mm thick PC material. While ensuring the requirements of light transmittance (for facilitating the viewing of test effects) and insulation (non-metallic conductor), they have good toughness and strength characteristics to ensure that the deformation of the vacuum cover during vacuum pumping is within the allowable range of strength. The bottom of the vacuum cover 19 is placed in the corresponding sealing groove 15 opened on the marble table 13, and an EPDM rubber sealing strip is placed in the sealing groove 15 to naturally form a sealed space during vacuum pumping.

[0057] The left starting air nozzle 603 and the right starting air nozzle 604 are parallelly and oppositely installed on both sides of the wind impeller 605, and are respectively aligned with the front and rear two fan blades of the wind impeller 605, and the jet flow rate can be precisely adjusted.

[0058] For the test system provided in Sampling Example 2, a ground test method for electromagnetic-vortex cancellation of a spatially rotating target includes the following steps:

[0059] Step 1: Level the marble table 610 equipped with the high-precision air bearing 609 using a spirit level. Then install the spatial target simulator 615 and level it again using the spirit level to ensure the levelness of the rotation of the spatial target simulator.

[0060] Step 2: Slightly rotate the spatial target simulator 615 and measure the runout of the top edge of the spatial target simulator 615 with a micrometer to ensure that the coaxiality is no greater than 0.05 mm in the rotating state of the target. Then tighten the taper bushing locking mechanism 614.

[0061] Step 3: Place the vacuum chamber and evacuate it with a vacuum pump until the vacuum degree reaches the test design requirement; and continuously evacuate with the vacuum pump during the test to always maintain this vacuum degree.

[0062] Step 4: Turn on the jet mechanism. The left starting nozzle 603 and the right starting nozzle 604 are aligned to jet air onto the wind impeller to slowly start the rotation of the spatial target simulator 615. Stop jetting after reaching and stabilizing at the desired rotational speed. Measure the change in the rotational speed decay of the spatial target simulator 615 until the spatial target simulator 615 stops rotating.

[0063] Step 5: The superconducting coil in the controllable superconducting magnetic field generating device for spatial electromagnetic control is maneuvered to the preset relative position and attitude through the servo guide rail and the servo turntable, and is energized to generate an electromagnetic field to reach the required magnetic field strength designed. Re-turn on the jet mechanism. The left starting nozzle 603 and the right starting nozzle 604 are aligned to jet air onto the wind impeller to slowly start the rotation of the spatial target simulator 615. Stop jetting after reaching and stabilizing at the desired rotational speed in Step 4. Measure the change in the rotational speed decay of the spatial target simulator 615 until the spatial target simulator 615 stops rotating.

[0064] Step 6: Compare the measurement results of Step 4 and Step 5, and the electromagnetic-vortex cancellation ability and action characteristics can be analyzed.

[0065] Set different required magnetic field strengths for the test and different desired rotational speeds of the spatial target simulator. Repeat the test according to the methods in Steps 1 to 6, and the electromagnetic-vortex cancellation ability and action characteristics at different magnetic field strengths and desired rotational speeds can be analyzed.

[0066] It should be noted again that the controllable superconducting magnetic field generating device for space electromagnetic manipulation provided by the present invention can be applied to various ground test systems for space electromagnetic manipulation. Embodiment 2 is only an application example of one aspect of a controllable superconducting magnetic field generating device for space electromagnetic manipulation of the present invention, and does not thereby limit the application of the present invention in other ground test systems related to electromagnetic docking and electromagnetic despinning.

[0067] In summary, although the present invention has been disclosed above in preferred embodiments, it is not intended to limit the present invention. Any person of ordinary skill in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A ground test system for space electromagnetic control, characterized in that, it includes a controllable superconducting magnetic field generating device for space electromagnetic control, which is used to generate the required controllable electromagnetic field, and also includes a space target simulation device; The controllable superconducting magnetic field generating device for space electromagnetic control includes a moving platform, a control system and a superconducting coil assembly. The superconducting coil assembly is used to generate an electromagnetic field under the control of the control system. The superconducting coil assembly is installed on the moving platform, supported by the moving platform and its movement is controlled through the moving platform; The controllable superconducting magnetic field generating device for space electromagnetic control is arranged on one side of the space target simulation device. Among them, the controllable superconducting magnetic field generating device for space electromagnetic control simulates a satellite, and the space target simulation device simulates another satellite. The relative movement of the two satellites is simulated through the servo guide rail and servo turntable in the controllable superconducting magnetic field generating device for space electromagnetic control, and a ground test of space rotating target electromagnetic-vortex cancellation is carried out to obtain the electromagnetic-vortex cancellation ability and action characteristics at different magnetic field intensities and desired rotational speeds; The space target simulation device includes a rotating platform bracket, a jet bracket, a left starting nozzle, a right starting nozzle, a wind impeller, a laser tachometer, a horizontal fine adjustment block, a dynamic seal air release port, a high-precision air bearing, a marble table, a positioning cone, a sealing groove, an air extraction hole, a cone sleeve locking mechanism, a space target simulation part, a vacuum cover, a tower-shaped multi-layer cover plate, and a self-locking bolt; the space target simulation part is arranged in a vacuum container. The vacuum container includes a vacuum cover and a tower-shaped multi-layer cover plate. The top surface of the vacuum cover is sealed by the tower-shaped multi-layer cover plate. The bottom of the vacuum cover is sealed and fixed on the marble table. The space target simulation part and the positioning cone are fixedly connected along the axis. The positioning cone is vertically inserted into the cone sleeve of the high-precision air bearing, and vertical fixation is realized through the cone sleeve locking mechanism; the high-precision air bearing is installed in the center of the marble table. The marble table is located above the rotating platform bracket, and the marble table is adjusted horizontally through four horizontal fine adjustment blocks in between; the wind impeller is installed at the center of the bottom of the high-precision air bearing. The left starting nozzle and the right starting nozzle are installed in parallel on the jet bracket, and the jet ports are aligned with the blades of the wind impeller; the laser tachometer is installed at an appropriate position on the rotating platform bracket and is aligned with the black and white graduation marks on the blades of the wind impeller. When the high-precision air bearing drives the space target simulation part to rotate, the real-time rotational speed of the space target simulation part is measured by the laser tachometer.

2. The ground test system for space electromagnetic control according to claim 1, characterized in that: The tower-shaped multi-layer cover plate includes multiple cover plates stacked in a tower shape. The multiple cover plates are fastened together through a self-locking bolt in the center; the bottom of the vacuum cover is placed in a sealing groove correspondingly opened on the marble table, and an EPDM rubber sealing strip is placed in the sealing groove.

3. The ground test system for space electromagnetic control according to claim 2, characterized in that: Four air extraction holes are provided on the marble table. The vacuum pump evacuates the space inside the vacuum hood through the four air extraction holes, and a sealed space is naturally formed during evacuation; a dynamic seal air leakage port is provided between the high-precision air bearing and the marble table. After the high-precision air bearing is ventilated, air is discharged through the dynamic seal air leakage port to minimize the entry of air into the space inside the vacuum hood.

4. The ground test system for space electromagnetic manipulation according to claim 1 or 2 or 3, characterized in that: The motion platform includes a support chassis, a servo guide rail, a turntable support, a servo turntable, and a mounting base. The superconducting coil assembly is installed on the mounting base, and the mounting base is fixed on the servo turntable. The rotation control of the superconducting coil assembly is realized by the servo turntable; the servo turntable is installed above the servo guide rail through the turntable support, and the turntable support can move along the guide rail direction of the servo guide rail, thereby driving the superconducting coil assembly to realize linear motion control; the servo guide rail is installed on the support chassis and is supported by the support chassis.

5. The ground test system for space electromagnetic manipulation according to claim 4, characterized in that: The superconducting coil assembly includes a vacuum dewar cylinder, a superconducting coil, a coil skeleton, a liquid nitrogen cavity, and coil leads; the liquid nitrogen cavity filled with liquid nitrogen is inside the vacuum dewar cylinder, and the superconducting coil and the coil skeleton are placed in the liquid nitrogen cavity, wherein the superconducting coil is wound around the coil skeleton; a lead socket is provided on the vacuum dewar cylinder, the inner and outer joints of the superconducting coil are connected to the coil leads, and the coil leads are powered by a 110A constant current source at the lead socket, so that the superconducting coil generates a magnetic field.

6. The ground test system for space electromagnetic manipulation according to claim 5, characterized in that: A vacuum insulation layer is coated on the inner side wall of the vacuum dewar cylinder.

7. The ground test system for space electromagnetic manipulation according to claim 5, characterized in that: A liquid nitrogen filling port for filling liquid nitrogen into the liquid nitrogen cavity is provided on the vacuum dewar cylinder, and liquid nitrogen is injected into the liquid nitrogen cavity through the liquid nitrogen filling port by using a self-pressurizing liquid nitrogen tank; the bottom center of the vacuum dewar cylinder is fixedly connected to the mounting base, and the surface of the mounting base is insulated.

8. The ground test system for space electromagnetic manipulation according to any one of claims 5 to 7, characterized in that: The superconducting coil assembly further includes temperature sensors provided in the liquid nitrogen cavity. The temperature sensors are PT100 sensors, and there are 2 in total, which are respectively placed at the top of the superconducting coil and at the intersection of the liquid nitrogen cavity and the liquid nitrogen filling port.

9. The ground test system for space electromagnetic manipulation according to claim 8, characterized in that: The length of the servo guide rail is 1100mm, and the positioning accuracy in the guide rail direction is 0.1mm; the stroke of the servo turntable is -180° to +180°, and the rotation accuracy is 0.1°.

10. The ground test system for space electromagnetic manipulation according to claim 8, characterized in that: The superconducting coil is made of high-temperature superconducting tape, and the main component is Bi-2223 / Ag; the superconducting coil is wound in a single-wire single-pancake manner, the inner diameter of the coil is 1m, the wire consumption is 800m, and the critical current of the superconducting coil is 85A.

11. The ground test system for space electromagnetic manipulation according to claim 8, characterized in that: The control system is used for the superconducting magnetic field control and motion control of the superconducting coil assembly; the control system includes a superconducting magnetic field control module and a servo control module; The superconducting magnetic field control module includes a coil current control unit, a coil temperature monitoring unit and a coil voltage monitoring unit; The coil current control unit is realized by connecting the coil lead through a constant current source; the coil temperature monitoring unit is realized by a 2-channel AD acquisition card, and the 2-channel AD acquisition card is respectively connected to 1 temperature sensor; the liquid nitrogen liquid level position is determined according to the temperature of the PT100 sensor. When the temperature is higher than 80K, liquid nitrogen needs to be replenished to ensure that the superconducting coil is always immersed in liquid nitrogen; the coil voltage monitoring unit includes a 1-channel AD acquisition card, and the 1-channel AD acquisition card is connected to the coil lead to judge whether the superconducting coil is in a superconducting state by collecting the voltage across the superconducting coil, preventing the superconducting coil from burning out during quenching; The motion control is realized through the servo control module. The servo control module is respectively connected to the servo guide rail and the servo turntable to realize linear motion control and azimuth rotation control.

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