CN106114919A - A kind of space junk rope system pulls racemization and method for cleaning - Google Patents

Abstract

A kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, relates to space junk racemization and method for cleaning, belongs to space technology field.The present invention passes through launching trolley spacecraft injection, completes the intersection with fragment；By many tethers, trailer is connected with fragment；Setting up kinetic model, the name rope of design control law regulation tether is long changes tether tension force, makes fragment racemization under many ropes coordinate, it is to avoid on fragment, projecting part is to tether cutting fracture, improves stability and redundancy that rope is acting trailer system；By trailer engine ignition, apply reversely to pull, space junk is drawn in atmosphere and burns, complete defragmentation.The present invention can be to space junk racemization, it is to avoid on fragment, projecting part is to tether cutting fracture, improves system stability, additionally, improve tether redundancy by increasing tether quantity.The present invention can be used for racemization and the cleaning of space junk.Can also be used for racemization and the control of other noncooperative target.

Description

A kind of space junk rope system pulls racemization and method for cleaning

Technical field

The present invention relates to a kind of space junk racemization and method for cleaning, particularly relate to that a kind of to use rope be the sky of pulling mode Between fragment racemization and method for cleaning, belong to space technology field, can be used for space junk (discarded satellite, rocket Upper Stage, blast Thing etc.) racemization and cleaning it can also be used to the racemization of other noncooperative target and control.

Background technology

Since the former Soviet Union is since nineteen fifty-seven succeeds in sending up its first man made earth satellite, and space debris population is along with people The solar-system operation of class occurs in that the growth of Fast Persistence.Show according to the up-to-date report data of issuing of NASA orbit debris project office Show, end on April 6th, 2016 and monitored 17385 large-scale targets in orbit, including 4041 payload and 13344 rocket rocket bodies, and the fragment Estimate of Total Number that diameter is more than 1 centimetre is in million magnitudes, main integrated distribution exists in height On LEO below 2000 kms and geostationary orbit.Scientist NASA Kessler just had been pointed out in 1978, space Collision between fragment can produce more fragment, thus greatly increases potential flakes hit probability, and thus causes broken Sheet quantity exponentially increases.It is true that the defending of the U.S.'s iridium satellite 33 occurred on February 10th, 2009 and Russian universe number 2251 Star whole star collision accident shows, the collision chain reaction of space junk has been triggered.Collision from fragment is likely to result in Spacecraft damage in various degree and destruction, carry out the safety of mankind's solar-system operation and cause threat greatly.Due to the earth It is extremely limited that air slows down effect for fragment, it is therefore necessary to fragment carries out aggressive cleaning (Gong Zizheng, Xu Kun Rich, Mu Yongqiang, Cao Yan. space debris environment present situation with actively remove technology [J]. Spacecraft Environment Engineering .2014,31 (2): 129-135)。

The space junk proposed at present actively manner of cleaning up, can be divided into three kinds (Lin Laixing. space junk present situation and cleaning [J]. spacecraft engineering .2012,21 (3): 1-10):

(1) passive method for cleaning.Clear up fragment by factor of natural environment so that it is leave the right or normal track, do not consume fuel.Typical case side Method has: electric power rope, aerodynamic drag, solar sail etc..

(2) actively method for cleaning.Need to consume fuel energy.As: motor power leaves the right or normal track, laser irradiates, the system that restricts pulls Arrest with robot for space.

(3) mixing method for cleaning.The method is two kinds of methods to be combined, and draws respective advantage.As braked sail and electricity The mixing of running rope, netting capture and the mixing etc. of electronic rope.

These method for cleaning are respectively arranged with pluses and minuses, in actual task, and can according to rail height, chip size and quantity etc. no Same factor, is respectively adopted distinct methods.Wherein, rope system dragging method is because it is lightweight, motility is high and control design case is simple Etc. advantage, become the defragmentation technology by focus of attention.Typical rope is that acting trailer system is made up of three parts: tool The trailer of standby host kinetic force, fragment for clearance, one connects fragment and the tether of trailer.But, prior art exist bright Aobvious shortcoming: in general, space junk is in rotation status, and the projecting part (such as solar array etc.) on fragment may be with tether Occur to be wound around cutting, cause projecting part to come off or tether fracture, thus cause clean-up task failure, even cause more fragment Generation.There is the problem that redundancy is relatively low in the rope system acting trailer system of single rope.

Summary of the invention

Increasingly the problem to space mission safety of the serious harm is increased for space junk, disclosed by the invention a kind of empty Between fragment rope system pull racemization and method for cleaning to solve the technical problem that and to be, pull defragmentation method basis in the system that restricted On, it is achieved the space junk being in rotation status is carried out racemization, to avoid the projecting part on fragment that tether is produced cutting Fracture, improves the stability that rope is acting trailer system, additionally, the present invention can also improve tether redundancy by increasing tether quantity Degree.

It is an object of the invention to be achieved through the following technical solutions.

A kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, is entered by launching trolley spacecraft Track, completes the intersection with fragment；By many tethers, trailer is attached with fragment；Setting up many ropes is the dynamic of acting trailer system Mechanical model, the name rope of design control law regulation tether is long, thus changes tether tension force, makes broken under the cooperation of many ropes Sheet racemization, it is to avoid the projecting part on fragment produces cutting fracture to tether, improves stability and redundancy that rope is acting trailer system Degree；Finally by trailer engine ignition, apply reversely to pull, space junk is drawn in atmosphere and burns, thus complete whole Defragmentation process.

Described tether can be accomplished in several ways with the connection of space junk, preferably fly pawl arrest, flying mesh capture or Fly lance to inject.

Described applying reversely pulls preferred thrust direction all the time along local level, contrary with the fragment direction of motion, thus Make fragment slowing effect optimum, effectively reduce fragment orbit altitude, make fragment step into atmosphere and burn.

Depending on the quantity of described many tethers is according to control task, preferably two.

A kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, owing to using between trailer and fragment Two tethers connect, and as caused a tethers fracture because of the winding of fragment projecting part cutting, also are able to by another tethers Complete fragment is pulled cleaning, therefore use two tethers to make system possess certain redundancy, reduce because tether fracture is drawn The fragment risk out of control risen.

A kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, comprises the steps:

Step one: launching trolley spacecraft injection, completes the intersection with fragment.

Step 2: trailer is attached with fragment by two tethers.

Tether can be accomplished in several ways with the connection of space junk, and pawl like flying is arrested, flying mesh captures, fly lance injects Deng.

Step 3: the rope regulating two tethers by long draw off gear of restricting is long, thus changes tether tension force, coordinates at two ropes Under make fragment racemization, it is to avoid the projecting part on fragment to tether produce cutting fracture, improve rope be stablizing of acting trailer system Property and redundancy.

Step 3.1: set up the kinetic model that rope is acting trailer system.

For describing the motion of the system of trailer-fragment composition, define orbital coordinate system C₀x₀y₀z₀As follows: initial point C₀It is positioned at and is System barycenter；x₀Outside axle is pointed to along local vertical by the earth's core；y₀Axle is in fragment orbit plane and x₀Axle is vertical, points to fragment The direction of motion；z₀Axle is perpendicular to fragment orbit plane, constitutes right-handed coordinate system.For describing the attitude of fragment, define fragment body Coordinate system C₂x₂y₂z₂As follows: initial point C₂It is positioned at fragment barycenter；Three coordinate axess are three principal axis of inertia of fragment rigid body.Trailer produces Raw thrust vectoring F size is permanent, and direction is all the time along-y₀Axle, i.e. at C₀x₀y₀z₀F=[0 ,-F, 0] is had under system.Two tethers exist The coordinate of two junction points on fragment is by C₂x₂y₂z₂Vector ρ under Xi_a=[x_a,y_a, 0] and ρ_b=[x_b,y_b, 0] be given.Under Mark a with b corresponding a rope and b respectively restrict.

Choose tri-variablees of φ, γ, l generalized coordinates as system: φ is x₂Axle and the angle of local vertical, suitable Clockwise is just；γ is the angle of fragment trailer barycenter line and local horizontal direction, is just clockwise；L is fragment Distance between barycenter and trailer barycenter.The system motion differential equation represented by generalized coordinates is obtained by Lagrange's equation As shown in formula (1), (2), (3), i.e. set up the kinetic model of duplex type system acting trailer system:

$\stackrel{\·\·}{\mathrm{\φ}}={\mathrm{\ϵ}}_0-\frac{3\mathrm{\μ}(J_y-J_x)}{2J_z{R}_0^3}sin2\mathrm{\φ}+\frac{{\mathrm{l\ξ}}_a}{J_z}{K}_a+\frac{{\mathrm{l\ξ}}_b}{J_z}{K}_b---\left(1\right)$

$\stackrel{\·\·}{\mathrm{\γ}}={\mathrm{\ϵ}}_0+2({\mathrm{\ω}}_0-\stackrel{\·}{\mathrm{\γ}})\frac{\stackrel{\·}{l}}{l}+\frac{3\mathrm{\μ}}{2R_0^3}sin2\mathrm{\γ}-\frac{{\mathrm{\ξ}}_a}{\stackrel{\‾}{m}l}{K}_a-\frac{{\mathrm{\ξ}}_b}{\stackrel{\‾}{m}l}{K}_b-\frac{F}{m_{1}l}sin\mathrm{\γ}---\left(2\right)$

$\stackrel{\·\·}{l}=l{({\mathrm{\ω}}_0-\stackrel{\·}{\mathrm{\γ}})}^2-\frac{\mathrm{\μ}l}{R_0^3}(1-3{\sin }^2\mathrm{\γ})-\frac{l-{\mathrm{\η}}_a}{\stackrel{\‾}{m}}{K}_a-\frac{l-{\mathrm{\η}}_b}{\stackrel{\‾}{m}}{K}_b+\frac{F}{m_1}cos\mathrm{\γ}---\left(3\right)$

Wherein, μ=3.986005 × 10¹⁴m³/s²For terrestrial gravitation parameter；J_x、J_yAnd J_zIt is that fragment principal axes of a body rotates Inertia；It it is trailer quality m₁With chip mass m₂Function,F is motor power amplitude；R₀It is Rope system acting trailer system barycenter C₀Instantaneous distance with the earth's core；ω₀And ε₀It is coordinate system C respectively₀x₀y₀z₀Instantaneous angular velocity and angle Acceleration；ξ_a、η_aAnd K_aExpression formula respectively as shown in formula (4), (5), (6):

ξ_a=x_acos(φ-γ)+y_asin(φ-γ) (4)

η_a=x_asin(φ-γ)-y_acos(φ-γ) (5)

$K_a=\frac{H(l_a-l_{a0})}{l_a}\[k_a(l_a-l_{a0})+c_a{\stackrel{\·}{l}}_a\]---\left(6\right)$

Wherein, k_a=EA/l_a0And c_a=DA/l_a0Being stiffness coefficient and the structure d amping coefficient of a rope respectively, E is Young mould Amount, D is damped coefficient, A and l_a0The cross-sectional area and the name rope that are a rope respectively are long.H () is He Wei Saden jump function.A restricts Actual rope long gone out as shown in formula (7) by generalized coordinates table:

$l_a={\[{(x_a-lsin(\mathrm{\φ}-\mathrm{\γ}\left)\right)}^2+{(y_a+lcos(\mathrm{\φ}-\mathrm{\γ}\left)\right)}^2\]}^{\frac{1}{2}}---\left(7\right)$

ξ_b、η_b、K_bAnd l_bExpression formula only subscript a in formula (4)-(7) need to be replaced to b.

Step 3.2: the name rope that design control law regulates two tethers is long, thus changes tether tension force, coordinates at two ropes Under make fragment racemization, it is to avoid the projecting part on fragment to tether produce cutting fracture, improve rope be stablizing of acting trailer system Property and redundancy.

Rope long draw off gear is installed on trailer spacecraft, regulates the nominal length l of two tethers_a0And l_b0Indirectly change Tether tension force, thus the rotation of fragment is suppressed.Controlling target is at set-point φ=φ by the attitude stabilization of fragment_d, Meanwhile, the most closely collide with trailer distance in order to avoid fragment, it is desirable to the centroid distance of fragment and trailer is controlled to given Value l=l_d.For convenience of design control law, equation (1) and (3) are rewritten into the most respectively as shown in formula (8), (9):

$\stackrel{\·\·}{\mathrm{\φ}}=h_{\mathrm{\φ}}+f_{\mathrm{\φ}}\·\frac{1}{l_{a0}}+g_{\mathrm{\φ}}\·\frac{1}{l_{b0}}---\left(8\right)$

$\stackrel{\·\·}{l}=h_l+f_l\·\frac{1}{l_{a0}}+g_l\·\frac{1}{l_{b0}}---\left(9\right)$

Wherein, h_φ、f_φ、g_φ、h_l、f_lAnd g_lExpression formula can be derived by by formula (1) and (3).

Introduce virtual controlling input u_φAnd u_lRespectively as shown in formula (10), (11):

$u_{\mathrm{\φ}}=f_{\mathrm{\φ}}\·\frac{1}{l_{a0}}+g_{\mathrm{\φ}}\·\frac{1}{l_{b0}}---\left(10\right)$

$u_l=f_l\·\frac{1}{l_{a0}}+g_l\·\frac{1}{l_{b0}}---\left(11\right)$

Then design of control law is formula (12), (13):

$u_{\mathrm{\φ}}=-h_{\mathrm{\φ}}-{\mathrm{\κ}}_{\mathrm{\φ}d}\stackrel{\·}{\mathrm{\φ}}-{\mathrm{\κ}}_{\mathrm{\φ}p}(\mathrm{\φ}-{\mathrm{\φ}}_d)---\left(12\right)$

$u_l=-h_l-{\mathrm{\κ}}_{ld}\stackrel{\·}{l}-{\mathrm{\κ}}_{lp}(l-l_d)---\left(13\right)$

Wherein, κ_φd、κ_φp、κ_ldAnd κ_lpBe take on the occasion of control gain.

The name rope of two tethers is long then to be solved by formula (10) and (11):

$l_{a0}=\frac{f_{\mathrm{\φ}}{g}_l-f_l{g}_{\mathrm{\φ}}}{u_{\mathrm{\φ}}{g}_l-u_l{g}_{\mathrm{\φ}}},l_{b0}=-\frac{f_{\mathrm{\φ}}{g}_l-f_l{g}_{\mathrm{\φ}}}{u_{\mathrm{\φ}}{f}_l-u_l{f}_{\mathrm{\φ}}}---\left(14\right)$

The name rope long value calculated according to formula (14) by the trailer long draw off gear of spaceborne rope regulates two ropes Rope is long, then be capable of the fragment by rotating stable at given attitude φ=φ_d, simultaneously by fragment and the centroid distance of trailer Stable at set-point l=l_d, it is to avoid the projecting part on fragment produces cutting fracture to tether, and improving rope is the steady of acting trailer system Qualitative, improve, by two tethers, the redundancy that rope is acting trailer system.

Step 4: trailer engine ignition, applies reversely to pull, space junk is drawn in atmosphere and burns, thus complete Whole defragmentation process.

Beneficial effect:

1, a kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, by between trailer and fragment Connect two ropes so that long by the rope being arranged on trailer long draw off gear regulation two rope rope, indirectly adjust tether tension force, The rotation of fragment can be suppressed under two ropes coordinate, make fragment rigid body stable in given attitude, it is possible to effectively to advise The projecting part kept away on fragment rigid body is wound around with tether, it is ensured that stablizing of whole rope system acting trailer system.

2, a kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, by between trailer and fragment Connect two ropes, compare traditional list rope rope system acting trailer system, increase tether redundancy, reduce because tether ruptures the fragment caused Risk out of control.

3, a kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning, described dynamic modeling method It is not limited to two tethers, it is possible to promote and be applicable to many tethers with design of control law method.

Accompanying drawing explanation

The schematic diagram of the space junk duplex type system acting trailer system that Fig. 1 present invention builds；

Fig. 2 is the workflow diagram that a kind of space junk disclosed by the invention rope system pulls racemization and method for cleaning；

Fig. 3 is each generalized coordinates and the time history of two rope rope length in embodiment.

Fig. 4 be single rope be the time history at acting trailer system φ angle.

Detailed description of the invention

The present invention will be further described with embodiment below in conjunction with the accompanying drawings.

Embodiment 1:

For the feasibility of verification method, one group Numerical Simulation Results is given below.The geometry physics of rope system acting trailer system The numerical simulation parameters such as parameter are listed in Table 1.

Table 1 numerical simulation parameter

Disclosed in the present embodiment, one space junk rope system pulls racemization and method for cleaning, can implement according to following steps, See Fig. 2.

Step one: launching trolley spacecraft injection, completes the intersection with fragment.

Step 2: trailer is attached with fragment by two tethers.

Step 3: set up the kinetic model of duplex type system acting trailer system, design control law regulates the name rope of two tethers Long, thus change tether tension force, under two ropes coordinate, make fragment racemization, it is to avoid tether is produced and cuts by the projecting part on fragment Cut off and split, improve stability and redundancy that rope is acting trailer system.

Rope long draw off gear is installed on trailer spacecraft, the nominal length l of two tethers can be regulated_a0And l_b0, indirectly Change tether tension force, thus the rotation of fragment is suppressed.Control target be by the attitude stabilization of fragment set-point φ= φ_d=45 °, meanwhile, in order to avoid fragment the most closely collides with trailer distance, it is desirable to by the centroid distance control of fragment and trailer System arrives set-point l=l_d=100m.

Design of control law is given by formula (12) and (13), and control gain value therein is κ_φd=κ_ld=0.1, κ_φp=κ_lp =0.0025.

The name rope of two tethers is long then to be solved by formula (10) and (11).

Five subgraphs of Fig. 3 depict three generalized coordinates and the time history data of two tethers name rope length respectively. Understood at initial time fragment with the angular velocity of 4 degree per second around z by the data in table 1₂Axle rotates counterclockwise.By trailer space flight Long draw off gear of restricting on device is long according to the aforementioned name rope long value regulation two rope rope calculated, and from Fig. 3 a, fragment is 300 Attitude φ=the φ given is converged in Miao_d=45 °, the centroid distance of Fig. 3 c display fragment and trailer has also converged to set-point L=l_d=100m.In initial 30 seconds, fragment attitude angle φ has the trend of reduction, and this is the counterclockwise rotation initial by fragment Tarnsition velocity causes.The most therefore, seeing in Fig. 3 d, a restricts during just starting to pull fragment progressively racemization, in order to keep away Exempting from tether and produce excessive tension force, a rope is ensureing that tether tension force is enough to also experience of short duration rope length while fragment slows down and releases Put.

In order to contrast, being that acting trailer system has been also carried out numerical simulation to single rope, Fig. 4 depicts the time of φ under single rope system Course curve.Because what φ portrayed is the fragment attitude relative to local vertical, Fig. 4 see, broken under single rope system Sheet presents and significantly swings up and down.Understand compared with the duplex type system φ curve shown in Fig. 3 a, the duplex type that the present embodiment builds It is that acting trailer system is compared traditional list rope system acting trailer system and had more preferable stability.

Step 4: trailer engine ignition, applies reversely to pull, space junk is drawn in atmosphere and burns, thus complete Whole scale removal process.

Owing to using two tethers to be connected between trailer with fragment, as caused one because of the winding of fragment projecting part cutting Tether ruptures, and also can complete by another tethers fragment is pulled cleaning, therefore make rope system acting trailer system possess certain Redundancy, reduces the fragment risk out of control caused because of tether fracture.

Above-described specific descriptions, are further elaborated to purpose, technical scheme and the beneficial effect of invention, Be it should be understood that the specific embodiment that the foregoing is only the present invention, the protection domain being not intended to limit the present invention, All within the spirit and principles in the present invention, any modification, equivalent substitution and improvement etc. done, should be included in the present invention's Within protection domain.

Claims (8)

1. space junk rope system pulls racemization and a method for cleaning, including step one: launching trolley spacecraft injection, complete Become the intersection with fragment；Step 4: trailer engine ignition, applies reversely to pull, space junk is drawn in atmosphere and burns, from And complete whole defragmentation process；It is characterized in that: also comprise the steps two, step 3,

Step 2: trailer is attached with fragment by two tethers；

Step 3: the rope regulating two tethers by long draw off gear of restricting is long, thus changes tether tension force, under two ropes coordinate Make fragment racemization, it is to avoid the projecting part on fragment to tether produce cutting fracture, improve rope be acting trailer system stability and Redundancy.

A kind of space junk the most according to claim 1 rope system pulls racemization and method for cleaning, it is characterised in that: step 3 Concrete methods of realizing is,

Step 3.1: set up the kinetic model that rope is acting trailer system；

For describing the motion of the system of trailer-fragment composition, define orbital coordinate system C₀x₀y₀z₀As follows, initial point C₀It is positioned at System Nature The heart；x₀Outside axle is pointed to along local vertical by the earth's core；y₀Axle is in fragment orbit plane and x₀Axle is vertical, points to fragment motion Direction；z₀Axle is perpendicular to fragment orbit plane, constitutes right-handed coordinate system；For describing the attitude of fragment, define fragment body coordinate It is C₂x₂y₂z₂As follows, initial point C₂It is positioned at fragment barycenter；Three coordinate axess are three principal axis of inertia of fragment rigid body；Trailer produces Thrust vectoring F size is permanent, and direction is all the time along-y₀Axle, i.e. at C₀x₀y₀z₀F=[0 ,-F, 0] is had under system；Two tethers are at fragment On the coordinate of two junction points by C₂x₂y₂z₂Vector ρ under Xi_a=[x_a,y_a, 0] and ρ_b=[x_b,y_b, 0] be given；Subscript a and B the most corresponding a rope and b restrict；

Choosing tri-variablees of φ, γ, l generalized coordinates as system, φ is x₂Axle and the angle of local vertical, clockwise Direction is just；γ is the angle of fragment trailer barycenter line and local horizontal direction, is just clockwise；L is fragment barycenter And the distance between trailer barycenter；The system motion differential equation such as public affairs represented by generalized coordinates is obtained by Lagrange's equation Shown in formula (1), (2), (3), i.e. set up the kinetic model of duplex type system acting trailer system,

$\stackrel{\·\·}{\mathrm{\φ}}={\mathrm{\ϵ}}_0-\frac{3\mathrm{\μ}(J_y-J_x)}{2J_z{R}_0^3}sin2\mathrm{\φ}+\frac{{\mathrm{l\ξ}}_a}{J_z}{K}_a+\frac{{\mathrm{l\ξ}}_b}{J_z}{K}_b---\left(1\right)$

$\stackrel{\·\·}{\mathrm{\γ}}={\mathrm{\ϵ}}_0+2({\mathrm{\ω}}_0-\stackrel{\·}{\mathrm{\γ}})\frac{\stackrel{\·}{l}}{l}+\frac{3\mathrm{\μ}}{2R_0^3}sin2\mathrm{\γ}-\frac{{\mathrm{\ξ}}_a}{\stackrel{\‾}{m}l}{K}_a-\frac{{\mathrm{\ξ}}_b}{\stackrel{\‾}{m}l}{K}_b-\frac{F}{m_{1}l}sin\mathrm{\γ}---\left(2\right)$

$\stackrel{\·\·}{l}=l{({\mathrm{\ω}}_0-\stackrel{\·}{\mathrm{\γ}})}^2-\frac{\mathrm{\μ}l}{R_0^3}(1-3{\sin }^2\mathrm{\γ})-\frac{l-{\mathrm{\η}}_a}{\stackrel{\‾}{m}}{K}_a-\frac{l-{\mathrm{\η}}_b}{\stackrel{\‾}{m}}{K}_b+\frac{F}{m_1}cos\mathrm{\γ}---\left(3\right)$

Wherein, μ=3.986005 × 10¹⁴m³/s²For terrestrial gravitation parameter；J_x、J_yAnd J_zIt it is fragment principal axes of a body rotary inertia；It it is trailer quality m₁With chip mass m₂Function,F is motor power amplitude；R₀It it is rope system Acting trailer system barycenter C₀Instantaneous distance with the earth's core；ω₀And ε₀It is coordinate system C respectively₀x₀y₀z₀Instantaneous angular velocity and angle accelerate Degree；ξ_a、η_aAnd K_aExpression formula respectively as shown in formula (4), (5), (6),

ξ_a=x_acos(φ-γ)+y_asin(φ-γ) (4)η_a=x_asin(φ-γ)-y_acos(φ-γ) (5)

$K_a=\frac{H(l_a-l_{a0})}{l_a}\[k_a(l_a-l_{a0})+c_a{\stackrel{\·}{l}}_a\]---\left(6\right)$

Wherein, k_a=EA/l_a0And c_a=DA/l_a0Being stiffness coefficient and the structure d amping coefficient of a rope respectively, E is Young's modulus, D It is damped coefficient, A and l_a0The cross-sectional area and the name rope that are a rope respectively are long；H () is He Wei Saden jump function；The reality of a rope Border rope is long to be gone out as shown in formula (7) by generalized coordinates table,

$l_a={\[{(x_a-lsin(\mathrm{\φ}-\mathrm{\γ}\left)\right)}^2+{(y_a+lcos(\mathrm{\φ}-\mathrm{\γ}\left)\right)}^2\]}^{\frac{1}{2}}---\left(7\right)$

ξ_b、η_b、K_bAnd l_bExpression formula only subscript a in formula (4) (7) need to be replaced to b；

Step 3.2: the name rope that design control law regulates two tethers is long, thus changes tether tension force, under two ropes coordinate Make fragment racemization, it is to avoid the projecting part on fragment to tether produce cutting fracture, improve rope be acting trailer system stability and Redundancy；

Rope long draw off gear is installed on trailer spacecraft, regulates the nominal length l of two tethers_a0And l_b0Indirectly change tether to open Power, thus the rotation of fragment is suppressed；Controlling target is at set-point φ=φ by the attitude stabilization of fragment_d, meanwhile, for Fragment and trailer distance is avoided the most closely to collide, it is desirable to control the centroid distance of fragment and trailer to set-point l=l_d； For convenience of design control law, equation (1) and (3) are rewritten into the most respectively as shown in formula (8), (9),

$\stackrel{\·\·}{\mathrm{\φ}}=h_{\mathrm{\φ}}+f_{\mathrm{\φ}}\·\frac{1}{l_{a0}}+g_{\mathrm{\φ}}\·\frac{1}{l_{b0}}---\left(8\right)$

$\stackrel{\·\·}{l}=h_l+f_l\·\frac{1}{l_{a0}}+g_l\·\frac{1}{l_{b0}}---\left(9\right)$

Wherein, h_φ、f_φ、g_φ、h_l、f_lAnd g_lExpression formula is derived by by formula (1) and (3)；

Introduce virtual controlling input u_φAnd u_lRespectively as shown in formula (10), (11),

$u_{\mathrm{\φ}}=f_{\mathrm{\φ}}\·\frac{1}{l_{a0}}+g_{\mathrm{\φ}}\·\frac{1}{l_{b0}}---\left(10\right)$

$u_l=f_l\·\frac{1}{l_{a0}}+g_l\·\frac{1}{l_{b0}}---\left(11\right)$

Then design of control law is formula (12), (13),

$u_{\mathrm{\φ}}=-h_{\mathrm{\φ}}-{\mathrm{\κ}}_{\mathrm{\φ}d}\stackrel{\·}{\mathrm{\φ}}-{\mathrm{\κ}}_{\mathrm{\φ}p}(\mathrm{\φ}-{\mathrm{\φ}}_d)---\left(12\right)$

$u_l=-h_l-{\mathrm{\κ}}_{ld}\stackrel{\·}{l}-{\mathrm{\κ}}_{lp}(l-l_d)---\left(13\right)$

Wherein, κ_φd、κ_φp、κ_ldAnd κ_lpBe take on the occasion of control gain；

The name rope of two tethers is long then to be solved by formula (10) and (11),

$l_{a0}=\frac{f_{\mathrm{\φ}}{g}_l-f_l{g}_{\mathrm{\φ}}}{u_{\mathrm{\φ}}{g}_l-u_l{g}_{\mathrm{\φ}}},l_{b0}=-\frac{f_{\mathrm{\φ}}{g}_l-f_l{g}_{\mathrm{\φ}}}{u_{\mathrm{\φ}}{f}_l-u_l{f}_{\mathrm{\φ}}}---\left(14\right)$

Two rope ropes are regulated according to the name rope long value that formula (14) calculates long by the trailer long draw off gear of spaceborne rope, Then it is capable of the fragment by rotating stable at given attitude φ=φ_d, simultaneously that the centroid distance of fragment and trailer is stable At set-point l=l_d, it is to avoid the projecting part on fragment produces cutting fracture to tether, and improving rope is stablizing of acting trailer system Property, improve, by two tethers, the redundancy that rope is acting trailer system.

A kind of space junk the most according to claim 1 and 2 rope system pulls racemization and method for cleaning, it is characterised in that: institute In the step 2 stated the connection of tether and space junk preferably fly pawl arrest, flying mesh capture or fly lance and inject.

A kind of space junk the most according to claim 1 and 2 rope system pulls racemization and method for cleaning, it is characterised in that: step Applying described in rapid four reversely pulls preferred thrust direction all the time along local level, contrary with the fragment direction of motion, so that Fragment slowing effect is optimum, effectively reduces fragment orbit altitude, makes fragment step into atmosphere and burn.

A kind of space junk the most according to claim 2 rope system pulls racemization and method for cleaning, it is characterised in that: described Dynamic modeling method and design of control law method are not limited to two tethers, it is possible to promote and be applicable to many tethers.

6. a space junk rope system pulls racemization and method for cleaning, it is characterised in that: enter rail by launching trolley spacecraft Road, completes the intersection with fragment；By many tethers, trailer is attached with fragment；Set up the power that many ropes are acting trailer system Learning model, the name rope of design control law regulation tether is long, thus changes tether tension force, makes fragment under the cooperation of many ropes Racemization, it is to avoid the projecting part on fragment produces cutting fracture to tether, improves stability and redundancy that rope is acting trailer system； Finally by trailer engine ignition, apply reversely to pull, space junk is drawn in atmosphere and burns, thus complete whole fragment Scale removal process.

A kind of space junk the most according to claim 6 rope system pulls racemization and method for cleaning, it is characterised in that: described By two tethers be attached trailer and fragment preferably flying pawl arrest, flying mesh capture or fly lance and inject.

8. pull racemization and method for cleaning according to a kind of space junk rope system described in claim 6 or 7, it is characterised in that: institute The applying stated reversely pulls preferred thrust direction all the time along local level, contrary with the fragment direction of motion, so that fragment slows down Effect is optimum, effectively reduces fragment orbit altitude, makes fragment step into atmosphere and burn.