A bidirectional non-uniform release and deployment control method for ultra-large-scale space tethers

Abstract

A bidirectional non-uniform release and deployment control method for a space super-large-scale tether is implemented through a space super-large-scale tether system, including an upper spacecraft, a lower spacecraft, a synchronous orbit station, an upper tether, and a lower tether. In the space super-large-scale tether system, the upper tether and the lower tether are used to connect the upper spacecraft, the synchronous orbit station and the lower spacecraft, the synchronous orbit station, and the two end tethers are respectively deployed along the upper and lower directions of the synchronous orbit station under the traction of the upper spacecraft and the lower spacecraft. At the same time, relying on the joint control of the upper spacecraft, the synchronous orbit station and the lower spacecraft, the stable release and deployment of all tethers is guaranteed.

Description

Technical Field

[0001] The invention relates to a bidirectional non-uniform release and deployment control method for a space super-large-scale tether, and belongs to the technical field of aircraft dynamics and control. Background Art

[0002] As a new concept of space transportation system, the Sky Ladder connects the Earth's surface with the space node above the geosynchronous orbit through a super-large-scale ribbon-shaped rope system, and uses the climbing device on the rope system to carry the payload into space. The stable deployment of the super-large-scale rope system (about 100,000 km in length) is the basis and key to the application and operation of the Sky Ladder system.

[0003] However, the deployment process covers the ground to high orbit, with strong cross-domain and complex interference factors, including atmospheric interference, high-altitude wind interference, etc. At the same time, the tether has low damping, high flexibility and huge scale, which will lead to extremely complex tether dynamics. The tether deployment control method of traditional space tethered satellites is only applicable to small-scale tethers (no more than tens of kilometers); facing the deployment process of super-large-scale tethers represented by the space ladder, the existing control method research leads to large propellant consumption, which is difficult to support by the propellant carried by the end vehicle itself. It is necessary to comprehensively consider the fuel consumption factor from both technical design and strategy formulation to design a stable control method for tether deployment. Summary of the invention

[0004] The technical problem solved by the present invention is: in view of the problem that it is difficult to achieve stable control of the deployment process of a space super-large-scale rope system represented by a ladder in the current existing technology, a bidirectional non-uniform release and deployment control method for a space super-large-scale rope system is proposed.

[0005] The present invention solves the above technical problems by the following technical solutions:

[0006] A bidirectional non-uniform release and deployment control method for a space super-large-scale tether is implemented by a space super-large-scale tether system, including an upper spacecraft, a lower spacecraft, a synchronous orbit station, an upper tether, and a lower tether, including:

[0007] Get the rope deployment task parameters;

[0008] Determining parameters of a space ultra-large-scale tether system; in the space ultra-large-scale tether system, an upper tether and a lower tether are used to connect an upper spacecraft, a synchronous orbital station and a lower spacecraft, a synchronous orbital station;

[0009] According to the mission duration constraint of the mission parameters, the acceleration trajectories of the upper and lower aircraft during the bidirectional non-uniform deployment of the tether are determined;

[0010] Perform quality judgment of the lower aircraft at the current moment, and if the judgment conditions are met, perform quality judgment of the upper aircraft at the current moment;

[0011] Make a quality judgment on the synchronous orbit station at the current moment;

[0012] Determine the control tension of the synchronous orbit station on the lower rope system and the control tension of the upper rope system at the current moment, and determine the radial component and tangential component of the tension of the upper rope system on the upper aircraft, the radial control thrust of the synchronous orbit station at the current moment, the radial control thrust and tangential control thrust of the lower aircraft, and the radial control thrust and tangential control thrust of the upper aircraft;

[0013] Determine the attitude command vector of the synchronous orbital station, the attitude command vector of the lower aircraft, and the attitude command vector of the upper aircraft at the previous moment;

[0014] Determine the synchronous orbit station control torque vector, the lower aircraft control torque vector, and the upper aircraft control torque vector at the current moment;

[0015] According to the obtained control force, attitude command vector and control torque vector, the attitude control is performed on the synchronous orbit station, the lower spacecraft and the upper spacecraft respectively, and the control tension is applied to the upper and lower rope systems at the same time;

[0016] After completing the attitude control, determine whether the lower-stage spacecraft has reached the predetermined landing point. If so, terminate the attitude control. Otherwise, re-judge the quality of the lower-stage spacecraft, the upper-stage spacecraft, and the synchronous orbit station and calculate the subsequent attitude control parameters until the lower-stage spacecraft reaches the predetermined landing point.

[0017] The rope deployment task parameters include the deployment time constraint T max , landing speed V Touch , the initial mass of the upper vehicle M Up0 , the initial mass of the lower vehicle M Down0 , the initial mass M of the synchronous orbit station GEO0 , the fuel consumption threshold M of the upper aircraft UpTh , the fuel consumption threshold M of the lower aircraft DownTh , the burnup threshold M of the synchronous orbit station GEOTh ;

[0018] The parameters of the space super-large-scale tether system include tether density γ, tether maximum cross-sectional area A m , characteristic length Rope elastic modulus E, rope design stress value σ0, maximum rope length L max .

[0019] The quality judgment of the lower aircraft at the current moment is specifically as follows:

[0020] Preset lower aircraft mass threshold M DownTh , determine the current time t k (k=0,1,2...) Lower aircraft mass M Down (t k ) whether it satisfies M Down (t k )≤M DownTh If it is satisfied, continue to judge the mass of the upper aircraft at the current moment, otherwise, refuel the lower aircraft according to the calculation and re-judge until the mass of the lower aircraft meets M Down (t k )≤M DownTh ,in:

[0021] Calculate the current time t k (k=0,1,2...) Expected velocity of the lower aircraft Determine the orbital altitude H for refueling of the lower vehicle Down , and transport the fuel to be replenished from the ground launch site to the calculated orbital height. The mass of the fuel to be replenished is M Down0 -M DownTh .

[0022] The upper aircraft quality judgment at the current moment is specifically as follows:

[0023] Preset upper aircraft mass threshold M UpTh , determine the current time t k (k=0,1,2...) Upper vehicle mass M Up (t k ) whether it satisfies M Up (t k )≤M UpTh If it is satisfied, otherwise, the upper aircraft is refueled according to the calculation and re-judged until the upper aircraft mass meets M Up (t k )≤M UpTh ,in:

[0024] Calculate the current time t k (k=0,1,2...) upper aircraft speed Determine the orbital altitude H for refueling of the upper vehicle Up , and transport the fuel to be replenished from the ground launch site to the orbital height. The mass of the fuel to be replenished is M Up0 -M UpTh .

[0025] The current synchronous orbit station quality judgment is specifically as follows:

[0026] Preset geostationary orbit station quality threshold M GEOTh, determine the current time t k (k=0,1,2...) Geostationary orbit mass M GEO (t k ) whether it satisfies M GEO (t k )≤M GEOTh If it is satisfied, then calculate the control tension F of the synchronous orbit station on the upper rope system and the lower rope system at the current moment UpT (t k ) and F DownT (t k );

[0027] If not, the number of refuelings to be added to the synchronous orbit station is determined to be M GEO0 -M GEOTh The fuel to be refueled is transported from the ground launch site to the geosynchronous orbit altitude to refuel the geosynchronous orbit station.

[0028] According to the current time t k (k=0,1,2...) The mass M of the lower aircraft Down (t k ), distance from the center of the earth Down (t k ) and acceleration a Down (t k ), the mass of the upper vehicle M Up (t k ), distance from the center of the earth Up (t k ) and acceleration a Up (t k ), the mass of the synchronous orbit station M GEO (t k ), determine the control tension F of the synchronous orbit station on the upper and lower rope systems at the current moment UpT (t k ) and F DownT (t k ).

[0029] Get the current time t k (k=0,1,2...) The mass M of the lower aircraft Down (t k ), speed v Down (t k ), angular velocity ω Down (t k ), acceleration a Down (t k ), expected speed The radial component F of the pulling force of the rope on the lower aircraft DownTR (t k ) and the tangential component FDownTN (t k ); the mass of the upper vehicle M Up (t k ), speed v Up (t k ), angular velocity ω Up (t k ), acceleration a Up (t k ), expected speed The radial component F of the pulling force of the rope on the upper aircraft UpTR (t k ) and the tangential component F UpTN (t k ), determine the radial control thrust F of the synchronous orbit station at the current moment GEOR (t k ), radial control thrust F of the lower vehicle DownR (t k ) and tangential control thrust F DownN (t k ), radial control thrust F of the upper vehicle UpR (t k ) and tangential control thrust F UpN (t k ).

[0030] According to the current time t k (k=0,1,2...) Radial control thrust F of the synchronous orbit station GEOR (t k ), radial control thrust F of the lower vehicle DownR (t k ) and tangential control thrust F DownN (t k ), radial control thrust F of the upper vehicle UpR (t k ) and tangential control thrust F UpN (t k ), determine the attitude command vector of the synchronous orbit station at the current moment Lower vehicle attitude command vector and the attitude command vector of the upper vehicle

[0031] Get the current time t k (k=0,1,2...) attitude vector θ of the synchronous orbit station GEO (t k ) and the angular velocity vector ω GEO (t k ), the lower vehicle attitude vector θ Down (t k ) and the angular velocity vector ωDown (t k ), and the upper vehicle attitude vector θ Up (t k ) and the angular velocity vector ω Up (t k ), determine the current synchronous orbit station control torque vector M GEO (t k ), the lower aircraft control torque vector M Down (t k ) and the upper vehicle control torque vector M Up (t k ).

[0032] Apply radial control force F to the synchronous orbit station GEOR (t k ) and the control torque vector M GEO (t k ), to achieve the current time t k (k=0,1,2...) position control of the synchronous orbit station; radial control force F is applied to the lower end spacecraft DownR (t k ), tangential control force F DownN (t k ) and the control torque vector M Down (t k ), to achieve the current time t k (k=0,1,2...) to control the position and attitude of the lower aircraft; and to implement radial control force F on the upper aircraft. UpR (t k ), tangential control force F UpN (t k ) and the control torque vector M Up (t k ), to achieve the current time t k (k=0,1,2...) The attitude control of the upper spacecraft; the tether control tension F is implemented on the upper tether release device of the synchronous orbit station UpT (t k ), the rope control tension F is applied to the lower rope release device of the synchronous orbit station DownT (t k ).

[0033] The advantages of the present invention compared with the prior art are:

[0034] (1) The present invention provides a bidirectional non-uniform release and deployment control method for a space ultra-large-scale tether, which adopts a tangential / radial composite control strategy of preset trajectory tracking. On the one hand, the preset non-uniform tether deployment motion trajectory is used to ensure the rapid release and reliable landing of the upper / lower section aircraft. On the other hand, the tangential / radial composite control is used to ensure that the aircraft motion meets the position and velocity constraints of the tether release process, while compensating for various disturbances.

[0035] (2) The present invention introduces a GEO orbital space station as an intermediate node, and effectively reduces the fuel consumption during the deployment of the tether by releasing the upper / lower section aircraft to pull the tether. At the same time, a joint control method for on-orbit fuel replenishment and robust attitude stabilization of the node aircraft based on fuel consumption prediction is proposed to achieve reasonable fuel replenishment and stable control of the node aircraft under the dual constraints of fuel transportation capacity and time, ensuring that the attitude of the upper / lower section aircraft is stable during the fuel replenishment process, and that the attitude control fuel consumption meets the constraints and the deployment configuration is stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the composition and bidirectional deployment mode of the space super-large-scale tether system provided for the invention;

[0037] Figure 2 An expanded control flow chart provided for the invention; DETAILED DESCRIPTION

[0038] A bidirectional non-uniform release and deployment control method of a space super-large-scale tether is implemented by a space super-large-scale tether system, including an upper spacecraft, a lower spacecraft, a synchronous orbit station, an upper tether, and a lower tether. In the space super-large-scale tether system, the upper tether and the lower tether are used to connect the upper spacecraft, the synchronous orbit station and the lower spacecraft, and the synchronous orbit station. The specific control method is as follows:

[0039] Get the rope deployment task parameters;

[0040] Determine the parameters of ultra-large-scale tether systems in space;

[0041] According to the mission duration constraint of the mission parameters, the acceleration trajectories of the upper and lower aircraft during the bidirectional non-uniform deployment of the tether are determined;

[0042] Perform quality judgment of the lower aircraft at the current moment, and if the judgment conditions are met, perform quality judgment of the upper aircraft at the current moment;

[0043] Make a quality judgment on the synchronous orbit station at the current moment;

[0044] Determine the control tension of the synchronous orbit station on the lower rope system and the control tension of the upper rope system at the current moment, and determine the radial component and tangential component of the tension of the upper rope system on the upper aircraft, the radial control thrust of the synchronous orbit station at the current moment, the radial control thrust and tangential control thrust of the lower aircraft, and the radial control thrust and tangential control thrust of the upper aircraft;

[0045] Determine the attitude command vector of the synchronous orbit station, the attitude command vector of the lower aircraft, and the attitude command vector of the upper aircraft at the current moment;

[0046] Determine the synchronous orbit station control torque vector, the lower aircraft control torque vector, and the upper aircraft control torque vector at the current moment;

[0047] According to the obtained control force, attitude command vector and control torque vector, the attitude control is performed on the synchronous orbit station, the lower spacecraft and the upper spacecraft respectively, and the control tension is applied to the upper and lower rope systems at the same time;

[0048] After completing the attitude control, determine whether the lower-stage spacecraft has reached the predetermined landing point. If so, terminate the attitude control. Otherwise, re-judge the quality of the lower-stage spacecraft, the upper-stage spacecraft, and the synchronous orbit station and calculate the subsequent attitude control parameters until the lower-stage spacecraft reaches the predetermined landing point.

[0049] The following is further described in conjunction with the accompanying drawings and preferred embodiments of the specification:

[0050] In the current embodiment, it is applied to a space ultra-large-scale tethered system represented by a sky ladder to solve the problem of stable control of release and deployment under the constraints of fuel consumption and deployment time, such as Figure 1 As shown, the space super-large-scale tether system consists of an upper spacecraft, a synchronous orbital station, a lower spacecraft and a tether, and the synchronous orbital station runs in the GEO orbit; one end of the upper tether is connected to the synchronous orbital station, and the other end is connected to the upper spacecraft, and the upper tether is continuously deployed and released by the upper tether releasing device installed on the synchronous orbital station; one end of the lower tether is connected to the synchronous orbital station, and the other end is connected to the lower spacecraft, and the lower tether is continuously deployed and released by the lower tether releasing device installed on the synchronous orbital station; under the action of the two tether releasing devices, the tethers at both ends are deployed along the upper and lower directions of the synchronous orbital station respectively under the traction of the upper spacecraft and the lower spacecraft, and at the same time, relying on the joint control of the upper spacecraft, the synchronous orbital station and the lower spacecraft, the stable release and deployment of all tethers is guaranteed.

[0051] like Figure 2 As shown, a bidirectional non-uniform speed deployment stabilization control method for a space super-large-scale tether includes the following steps:

[0052] (1) Obtain task parameters, including the expansion time constraint Tmax , landing speed V Touch (can be set to 30m / s), the initial mass of the upper aircraft M Up0 , the initial mass of the lower vehicle M Down0 , the initial mass M of the synchronous orbit station GEO0 , the fuel consumption threshold M of the upper aircraft UpTh , the fuel consumption threshold M of the lower aircraft DownTh , the burnup threshold M of the synchronous orbit station GEOTh .

[0053] (2) Obtain the parameters of the rope system, including the rope density γ and the maximum cross-sectional area A of the rope system m , characteristic length Rope elastic modulus E, rope design stress value σ0, maximum rope length L max , usually set to L max =100000km,

[0054] (3) According to the task duration constraint, the acceleration trajectories of the upper and lower aircraft during the bidirectional non-uniform deployment of the tether are determined according to the following steps.

[0055] Sub-step 1: Select parameter a Down1 ,a Down2 and R Down1 ,R Down2 , so that the following equation holds

[0056] T Down1 +T Down2 +T Down2 ≤T max / 2

[0057] in

[0058]

[0059] In the formula, H G is the geosynchronous orbit altitude, R E is the radius of the earth. Therefore, the acceleration trajectory of the lower aircraft is obtained and satisfies the following formula:

[0060]

[0061] Among them, r Down is the distance from the center of the earth to the lower aircraft.

[0062] Sub-step 2: Select parameter a Up1 ,a Up2 and R Up1 ,R Up2 , so that the following equation holds

[0063]

[0064] Among them, H G is the geosynchronous orbit altitude,

[0065]

[0066] Therefore, the acceleration trajectory of the upper aircraft is obtained and satisfies the following equation:

[0067]

[0068] Among them, r Up is the distance from the center of the earth to the upper aircraft.

[0069] (4) Determine the current time t k (k=0,1,2...) Lower aircraft mass M Down (t k ) whether it reaches the threshold M DownTh , that is, to judge M Down (t k )≤M DownTh If satisfied, then go to step (5), otherwise, go to step (6).

[0070] (5) Calculate the current time t k (k=0,1,2...) Expected velocity of the lower aircraft Considering the time consumed by ground launch and space transfer, the orbital height H for fuel replenishment of the lower spacecraft is determined according to the following formula: Down The fuel to be added is transported from the ground launch site to the orbital altitude, and the lower spacecraft is refueled. The mass of the fuel to be added is M Down0 -M DownTh .

[0071]

[0072] Among them, H0 is the transition orbit altitude, which can be set to 200km, μ is the earth's gravitational constant, and T0 is the transition orbit flight time, which can be set to 500s.

[0073] (6) Determine the current time t k (k=0,1,2...) Upper vehicle mass M Up (t k ) whether it reaches the threshold M UpTh , that is, to judge M Up (t k )≤M UpTh , if satisfied, then go to step (7), otherwise, go to step (8).

[0074] (7) Calculate the current time t k(k=0,1,2...) upper aircraft speed Considering the time consumed by ground launch and space transfer, the orbital altitude H for refueling the upper spacecraft is determined according to the following formula: Up The fuel to be added is transported from the ground launch site to the orbital altitude, and the upper spacecraft is refueled. The mass of the fuel to be added is M Up0 -M UpTh .

[0075]

[0076] (8) Determine the current time t k (k=0,1,2...) Geostationary orbit mass M GEO (t k ) whether it reaches the threshold M GEOTh , that is, to judge M GEO (t k )≤M GEOTh If satisfied, then go to step (9), otherwise, go to step (10).

[0077] (9) Determine the amount of fuel to be added to the synchronous orbit station M GEO0 -M GEOTh The fuel to be refueled is transported from the ground launch site to the geosynchronous orbit altitude to refuel the geosynchronous orbit station.

[0078] (10) Get the current time t k (k=0,1,2...) The mass M of the lower aircraft Down (t k ), distance from the center of the earth Down (t k ) and acceleration a Down (t k ), the mass of the upper vehicle M Up (t k ), distance from the center of the earth Up (t k ) and acceleration a Up (t k ), the mass of the synchronous orbit station M GEO (t k ), determine the current time t by the following formula k (k=0,1,2...) The control tension of the lower rope system by the synchronous orbit station

[0079]

[0080] in,

[0081]

[0082] At the same time, the current time t is determined by the following formula k (k=0,1,2...) The control tension of the upper rope system by the synchronous orbit station

[0083]

[0084] (11) Get the current time t k (k=0,1,2..the mass of the lower aircraft M Down (t k ), speed v Down (t k ), angular velocity ω Down (t k ), acceleration a Down (t k ), expected speed The radial component F of the pulling force of the rope on the lower aircraft DownTR (t k ) and the tangential component F DownTN (t k ); the mass of the upper vehicle M Up (t k ), speed v Up (t k ), angular velocity ω Up (t k ), acceleration a Up (t k ), expected speed The radial component F of the pulling force of the rope on the upper aircraft UpTR (t k ) and the tangential component F UpTN (t k ), the radial control thrust F of the synchronous orbit station at the current moment is determined by the following formula: GEOR (t k ), radial control thrust F of the lower vehicle DownR (t k ) and tangential control thrust F DownN (t k ), radial control thrust F of the upper vehicle UpR (t k ) and tangential control thrust F UpN (t k )

[0085] F GEOR (t k )=F UpT (t k )-F DownT (t k )

[0086]

[0087] F DownN (t k )=2M Down (t k )v Down (t k )ω Down (t k )+F DownTN (t k )

[0088]

[0089] F UpN (t k )=2M Up (t k )v Up (t k )ω Up (t k )+F UpTN (t k )

[0090] (12) According to the current time t k (k=0,1,2...) Radial control thrust F of the synchronous orbit station GEOR (t k ), radial control thrust F of the lower vehicle DownR (t k ) and tangential control thrust F DownN (t k ), radial control thrust F of the upper vehicle UpR (t k ) and tangential control thrust F UpN (t k ), the synchronous orbit station attitude command vector at the current moment is determined by the following formula: Lower vehicle attitude command vector and the attitude command vector of the upper vehicle

[0091]

[0092] (13) Get the current time t k (k=0,1,2...) attitude vector θ of the synchronous orbit station GEO (t k ) and the angular velocity vector ω GEO (t k ), the lower vehicle attitude vector θ Down (t k ) and the angular velocity vector ω Down (t k), and the upper vehicle attitude vector θ Up (t k ) and the angular velocity vector ω Up (t k ), the current synchronous orbit station control torque vector M is determined as follows: GEO (t k ), the lower aircraft control torque vector M Down (t k ) and the upper vehicle control torque vector M Up (t k )

[0093]

[0094]

[0095]

[0096] Among them, k GEO ,k Down ,k Up are the given proportional gains of the synchronous orbit station, the lower spacecraft and the upper spacecraft respectively, k GEOD ,k DownD ,k UpD are the given differential gains of the synchronous orbit station, the lower spacecraft and the upper spacecraft respectively.

[0097] (14) Apply radial control force F to the synchronous orbit station GEOR (t k ) and the control torque vector M GEO (t k ), to achieve the current time t k (k=0,1,2...) position control of the synchronous orbit station; radial control force F is applied to the lower end spacecraft DownR (t k ), tangential control force F DownN (t k ) and the control torque vector M Down (t k ), to achieve the current time t k (k=0,1,2...) to control the position and attitude of the lower aircraft; and to implement radial control force F on the upper aircraft. UpR (t k ), tangential control force F UpN (t k ) and the control torque vector M Up (t k ), to achieve the current time t k(k=0,1,2...) The attitude control of the upper spacecraft; the tether control tension F is implemented on the upper tether release device of the synchronous orbit station UpT (t k ), the rope control tension F is applied to the lower rope release device of the synchronous orbit station DownT (t k ).

[0098] (15) Determine whether the next stage aircraft has reached the predetermined landing point. If so, r Down (t k )=R E , then the control ends, otherwise returns to step (4) until the lower aircraft reaches the predetermined landing point.

[0099] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

[0100] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A bidirectional non-uniform release and deployment control method for a space super-large-scale tether, implemented by a space super-large-scale tether system, comprising an upper-end spacecraft, a lower-end spacecraft, a synchronous orbit station, an upper-end tether, and a lower-end tether, characterized in that include: Get the rope deployment task parameters; Determining parameters of a space ultra-large-scale tether system; in the space ultra-large-scale tether system, an upper tether and a lower tether are used to connect an upper spacecraft, a synchronous orbital station and a lower spacecraft, a synchronous orbital station; According to the mission duration constraint of the mission parameters, the acceleration trajectories of the upper and lower aircraft during the bidirectional non-uniform deployment of the tether are determined; Perform quality judgment of the lower aircraft at the current moment, and if the judgment conditions are met, perform quality judgment of the upper aircraft at the current moment; Make a quality judgment on the synchronous orbit station at the current moment; Determine the control tension of the synchronous orbit station on the lower rope system and the control tension of the upper rope system at the current moment, and determine the radial component and tangential component of the tension of the upper rope system on the upper aircraft, the radial control thrust of the synchronous orbit station at the current moment, the radial control thrust and tangential control thrust of the lower aircraft, and the radial control thrust and tangential control thrust of the upper aircraft; Determine the attitude command vector of the synchronous orbital station, the attitude command vector of the lower aircraft, and the attitude command vector of the upper aircraft at the previous moment; Determine the synchronous orbit station control torque vector, the lower aircraft control torque vector, and the upper aircraft control torque vector at the current moment; According to the obtained control force, attitude command vector and control torque vector, the attitude control is performed on the synchronous orbit station, the lower spacecraft and the upper spacecraft respectively, and the control tension is applied to the upper and lower rope systems at the same time; After completing the attitude control, determine whether the lower-stage spacecraft has reached the predetermined landing point. If so, terminate the attitude control. Otherwise, re-judge the quality of the lower-stage spacecraft, the upper-stage spacecraft, and the synchronous orbit station and calculate the subsequent attitude control parameters until the lower-stage spacecraft reaches the predetermined landing point.

2. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 1 is characterized in that: The rope deployment task parameters include the deployment time constraint T max , landing speed V Touch , the initial mass of the upper vehicle M Up0 , the initial mass of the lower vehicle M Down0 , the initial mass M of the synchronous orbit station GEO0 , the fuel consumption threshold M of the upper aircraft UpTh , the fuel consumption threshold M of the lower aircraft DownTh , the burnup threshold M of the synchronous orbit station GEOTh ; The parameters of the space super-large-scale tether system include tether density γ, tether maximum cross-sectional area A m , characteristic length Rope elastic modulus E, rope design stress value σ0, maximum rope length L max .

3. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 2 is characterized in that: The quality judgment of the lower aircraft at the current moment is specifically as follows: Preset lower aircraft mass threshold M DownTh , determine the current time t k (k=0,1,2...) Lower aircraft mass M Down (t k ) whether it satisfies M Down (t k )≤M DownTh If it is satisfied, continue to judge the mass of the upper aircraft at the current moment, otherwise, refuel the lower aircraft according to the calculation and re-judge until the mass of the lower aircraft meets M Down (t k )≤M DownTh ,in: Calculate the current time t k (k=0,1,2...) Expected velocity of the lower aircraft Determine the orbital altitude H for refueling of the lower vehicle Down , and transport the fuel to be replenished from the ground launch site to the calculated orbital height. The mass of the fuel to be replenished is M Down0 -M DownTh .

4. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 3 is characterized by: The upper aircraft quality judgment at the current moment is specifically as follows: Preset upper aircraft mass threshold M UpTh , determine the current time t k (k=0,1,2...) Upper vehicle mass M Up (t k ) whether it satisfies M Up (t k )≤M UpTh If it is satisfied, otherwise, the upper aircraft is refueled according to the calculation and re-judged until the upper aircraft mass meets M Up (t k )≤M UpTh ,in: Calculate the current time t k (k=0,1,2...) upper aircraft speed Determine the orbital altitude H for refueling of the upper vehicle Up , and transport the fuel to be replenished from the ground launch site to the orbital height. The mass of the fuel to be replenished is M Up0 -M UpTh .

5. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 4 is characterized in that: The current synchronous orbit station quality judgment is specifically as follows: Preset geostationary orbit station quality threshold M GEOTh , determine the current time t k (k=0,1,2...) Geostationary orbit mass M GEO (t k ) whether it satisfies M GEO (t k )≤M GEOTh If it is satisfied, then calculate the control tension F of the synchronous orbit station on the upper rope system and the lower rope system at the current moment UpT (t k ) and F DownT (t k ); If not, the number of refuelings to be added to the synchronous orbit station is determined to be M GEO0 -M GEOTh The fuel to be refueled is transported from the ground launch site to the geosynchronous orbit altitude to refuel the geosynchronous orbit station.

6. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 5 is characterized by: According to the current time t k (k=0,1,2...) The mass M of the lower aircraft Down (t k ), distance from the center of the earth r Down (t k ) and acceleration a Down (t k ), the mass of the upper vehicle M Up (t k ), distance from the center of the earth Up (t k ) and acceleration a Up (t k ), the mass of the synchronous orbit station M GEO (t k ), determine the control tension F of the synchronous orbit station on the upper and lower rope systems at the current moment UpT (t k ) and F DownT (t k ).

7. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 6 is characterized by: Get the current time t k (k=0,1,2...) The mass M of the lower aircraft Down (t k ), speed v Down (t k ), angular velocity ω Down (t k ), acceleration a Down (t k ), expected speed The radial component F of the pulling force of the rope on the lower aircraft DownTR (t k ) and the tangential component F DownTN (t k ); the mass of the upper vehicle M Up (t k ), speed v Up (t k ), angular velocity ω Up (t k ), acceleration a Up (t k ), expected speed The radial component F of the pulling force of the rope on the upper aircraft UpTR (t k ) and the tangential component F UpTN (t k ), determine the radial control thrust F of the synchronous orbit station at the current moment GEOR (t k ), radial control thrust F of the lower vehicle DownR (t k ) and tangential control thrust F DownN (t k ), radial control thrust F of the upper vehicle UpR (t k ) and tangential control thrust F UpN (t k ).

8. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 7 is characterized by: According to the current time t k (k=0,1,2...) Radial control thrust F of the synchronous orbit station GEOR (t k ), radial control thrust F of the lower vehicle DownR (t k ) and tangential control thrust F DownN (t k ), radial control thrust F of the upper vehicle UpR (t k ) and tangential control thrust F UpN (t k ), determine the attitude command vector of the synchronous orbit station at the current moment Lower vehicle attitude command vector and the attitude command vector of the upper vehicle 9. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 8, characterized in that: Get the current time t k (k=0,1,2...) attitude vector θ of the synchronous orbit station GEO (t k ) and the angular velocity vector ω GEO (t k ), the lower vehicle attitude vector θ Down (t k ) and the angular velocity vector ω Down (t k ), and the upper vehicle attitude vector θ Up (t k ) and the angular velocity vector ω Up (t k ), determine the current synchronous orbit station control torque vector M GEO (t k ), the lower aircraft control torque vector M Down (t k ) and the upper vehicle control torque vector M Up (t k ).

10. The bidirectional non-uniform release and deployment control method of a space super-large-scale tether according to claim 9, characterized in that: Apply radial control force F to the synchronous orbit station GEOR (t k ) and the control torque vector M GEO (t k ), to achieve the current time t k (k=0,1,2...) position control of the synchronous orbit station; radial control force F is applied to the lower end spacecraft DownR (t k ), tangential control force F DownN (t k ) and the control torque vector M Down (t k ), to achieve the current time t k (k=0,1,2...) to control the position and attitude of the lower aircraft; and to apply radial control force F to the upper aircraft. UpR (t k ), tangential control force F UpN (t k ) and the control torque vector M Up (t k ), to achieve the current time t k (k=0,1,2...) The attitude control of the upper spacecraft; the tether control tension F is implemented on the upper tether release device of the synchronous orbit station UpT (t k ), the rope control tension F is applied to the lower rope release device of the synchronous orbit station DownT (t k ).

Images