CN104317303A - Method for controlling formation maintenance or flying-around withdrawal of spacecraft - Google Patents

Abstract

The invention discloses a method for controlling formation maintenance or flying-around withdrawal of spacecraft. In two adjacent orbit periods of the target spacecraft, integration is performed on the x-coordinate component of the coordinate system of the main control spacecraft relative to the target spacecraft, a difference quotient of the integration result relative to the square of each corresponding period is obtained, and therefore, a period average drift velocity can be obtained; an expected period average drift velocity after the completion of formation maintenance control or flying-around withdrawal is set according to requirements, the period average drift velocity before control is subtracted from the expected period average drift velocity to obtain a period average drift velocity increment, and the horizontal components of double pulses of the formation maintenance control and single pulse of the flying-around withdrawal control both are obtained by virtue of calculation based on the increment; as a result, the formation maintenance control has the characteristics of independence, low frequentness and the like, and the lying-around withdrawal is independent, and safe and quick.

Description

A kind of Spacecraft formation maintains or the control method of withdrawing of being diversion

Technical field

The invention belongs to Spacecraft Formation Flying guidance, control technology field, be specifically related to the maintenance of a kind of Spacecraft formation or the control method of withdrawing of being diversion.

Background technology

In Spacecraft Formation Flying field, generally exist with flying, leading relative motion forms such as flying and be diversion between two spacecrafts.Master control spacecraft surrounding target spacecraft does oval relative motion and is called and is diversion, and master control spacecraft is followed and done relative motion after passive space vehicle, is called with flying, and is called that neck flies above.And master control spacecraft enters with flying or lead the state of flying from the state of being diversion for passive space vehicle, being then called is diversion withdraws.The motion of the master control spacecraft relative target spacecraft orbits controlling maintained in the specific interval range of passive space vehicle orbital coordinate system x-axis is called, and formation maintains control.

In formation flight engineering reality, master control spacecraft always drifts about along near-circular orbit passive space vehicle orbital coordinate system+x or-x direction relative to the relative motion configuration of passive space vehicle.In order to reduce as far as possible with the relative motion state that flies, leads to fly or be diversion maintenance frequency, guarantee to maintain safe spacing between two spacecrafts, accurate description relative motion complete cycle configuration has great engineering practical value in the average drift movement velocity in passive space vehicle orbital coordinate system x-axis direction.The free movement analytic solution of existing CW equation comprise a CW drift velocity parameter, but due to CW equation be in formation flight process master control spacecraft relative to the approximate description of the relative motion of passive space vehicle, the relative practical situation error of CW drift velocity is comparatively large, is not enough to the drift velocity of accurate description and forecast relative motion complete cycle configuration.In formation flight field, a relative drift rate parameter is there is in the Relative Orbit Elements theory that development in recent years is got up, make difference by master control spacecraft mean orbit angular velocity relative to passive space vehicle mean orbit angular velocity to obtain, identical with the conceptual nature being called as mean longitude degree drift rate used in the retentive control of high rail satellite position, it is the accurate description of the drift motion trend to relative motion complete cycle configuration, just immeasurable, but because mean orbit angular velocity is difficult to Obtaining Accurate accurately, so this parameter is also inconvenient in Practical Project uses.

Summary of the invention

Technical matters to be solved by this invention is to provide a kind of Spacecraft formation and maintains or the control method of withdrawing of being diversion, and makes formation maintain control and has the features such as autonomous and low-frequency degree, and making to be diversion, it is autonomous and safe and efficient to withdraw.

Technical scheme of the present invention is:

A kind of Spacecraft formation maintains control method, and step is as follows:

(1) when expecting that in follow-up a period of time, orbits controlling all can not occur for master control spacecraft and passive space vehicle, a sampling initial time t carrying out cycle average drift velocity calculating is specified ₀₀;

(2) cycle average drift velocity is carried out as follows calculating:

${\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t\right)=\frac{{\∫}_{t_0+T}^{t_0+2T}{x}_r\left(t\right)\mathrm{dt}-{\∫}_{t_0}^{t_0+T}{x}_r\left(t\right)\mathrm{dt}}{T^2}$

X in formula _rt () is the x-axis location components of master control spacecraft in the orbital coordinate system of passive space vehicle corresponding to sampling instant t, obtain according to measurement; T is the passive space vehicle orbital period; t ₀for the integration initial time of previous orbital period in adjacent two orbital periods, t ₀value is:

$t_0=\left\{\begin{array}{cc}{t}_{00}& t\≤t_{00}+2T\\ t-2T& t>t_{00}+2T\end{array}\right.;$

(3) judge whether moment t meets t>t ₀₀+ 2T, when meeting t>t ₀₀during+2T, obtain the cycle average drift velocity result that first convergence is available, and proceed to step (4); Otherwise, return step (2);

(4) judge whether moment t arrives to form into columns to maintain and control Startup time t _beforeKeepif, due in t _beforeKeep, obtain this moment t _beforeKeepcorresponding cycle average drift velocity proceed to step (5); If there is no due in t _beforeKeep, then step (2) is returned;

(5) according to cycle average drift velocity cycle average drift velocity after having controlled with the maintenance expected computation period average drift velocity increment

$\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Keep}}={\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{after\; K\; eep}}\right)-{\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{before\; K\; eep}}\right)$

(6) according to cycle average drift velocity increment calculating forms into columns maintains in level of control dipulse the formation component Δ v realizing the long adjustment of relative major semi-axis _a:

$\mathrm{\Δ}{v}_a=-\frac{1}{3}\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Keep}}$

(7) the relative eccentric ratio vector before controlling to implement is maintained according to forming into columns target relative eccentric ratio vector after having controlled with the maintenance expected calculate relative eccentric ratio delta vector wherein and determine relative eccentric ratio delta vector at passive space vehicle nodal coordinate system Ox _ny _nz _nmiddle x _naxle and y _nthe coordinate components δ Δ e of axle _xwith δ Δ e _y;

(8) according to formula calculate the amplitude δ Δ e of relative eccentric ratio delta vector; The formation component Δ v forming into columns and maintain and realize relative eccentric ratio adjustment in level of control dipulse is calculated according to the amplitude δ Δ e of relative eccentric ratio delta vector _e:

$\mathrm{\Δ}{v}_e=\frac{{\stackrel{\‾}{a}}_{t\arg \mathrm{et}}{n}_{t\arg \mathrm{et}}}{4}\mathrm{\δ\Δe}$

In formula for the flat major semi-axis of passive space vehicle is long, n _targetfor the track angular speed of passive space vehicle;

(9) according to Δ v _awith Δ v _edetermine the horizontal dipulse size maintaining and control of forming into columns, computing formula is:

$\mathrm{\Δ}{v}_{x1}=\frac{1}{2}\mathrm{\Δ}{v}_a+\mathrm{\Δ}{v}_e,$

$\mathrm{\Δ}{v}_{x2}=\frac{1}{2}\mathrm{\Δ}{v}_a-\mathrm{\Δ}{v}_e,$

Wherein, Δ v _x1be the size of the first pulse, Δ v _x2it is the size of the second pulse;

(10) according to δ Δ e _x, δ Δ e _ydetermine the track argument of horizontal dipulse application point on master control spacecraft:

u _x1＝atan2(δΔe _y,δΔe _x)

u _x2＝atan2(-δΔe _y,-δΔe _x)

Wherein, u _x1for the track argument of described first pulse application point on master control spacecraft, u _x2for the track argument of described second pulse application point on master control spacecraft, atan2 ( ^★, ^★) the expansion codomain that is suitable for for engineering is to the arctan function of [-π, π] scope;

(11) at track argument u _x1place applies the first pulse Δ v to master control spacecraft _x1, at track argument u _x2place applies the second pulse Δ v to master control spacecraft _x2, completing forms into columns maintains control.

The orbital coordinate system of passive space vehicle is defined as: initial point C is positioned at passive space vehicle barycenter, and z-axis points to direction, the earth's core by passive space vehicle barycenter, and x-axis is vertical with z-axis and point to passive space vehicle heading, and y-axis and z-axis and x-axis meet right-hand rule.

When the motion of master control spacecraft relative target spacecraft exceeds the specific interval range of passive space vehicle orbital coordinate system x-axis, think that moment t arrives to form into columns to maintain instantly and control Startup time t _beforeKeep, otherwise, think that moment t not yet arrives to form into columns to maintain instantly and control Startup time t _beforeKeep.

Passive space vehicle nodal coordinate system is defined as: initial point Ο is the earth's core, axle x _npassive space vehicle ascending node of orbit is pointed to, axle z from Ο _nalong passive space vehicle orbital angular momentum vector direction, axle y _nwith z _naxle and x _naxle meets right-hand rule.

A kind of spacecraft is diversion and withdraws control method, and step is as follows:

(1) when expecting that in follow-up a period of time, orbits controlling all can not occur for master control spacecraft and passive space vehicle, a sampling initial time t carrying out cycle average drift velocity calculating is specified ₀₀;

(2) cycle average drift velocity is carried out as follows calculating:

${\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t\right)=\frac{{\∫}_{t_0+T}^{t_0+2T}{x}_r\left(t\right)\mathrm{dt}-{\∫}_{t_0}^{t_0+T}{x}_r\left(t\right)\mathrm{dt}}{T^2}$

X in formula _rt () is the x-axis location components of master control spacecraft in the orbital coordinate system of passive space vehicle corresponding to sampling instant t, obtain according to measurement; T is the passive space vehicle orbital period; t ₀for the integration initial time of previous orbital period in adjacent two orbital periods, t ₀value is:

$t_0=\left\{\begin{array}{cc}{t}_{00}& t\≤t_{00}+2T\\ t-2T& t>t_{00}+2T\end{array}\right.;$

(3) judge whether moment t meets t>t ₀₀+ 2T, when meeting t>t ₀₀during+2T, obtain the cycle average drift velocity result that first convergence is available, and proceed to step (4); Otherwise, return step (2);

(4) judge whether moment t arrives the departure time t that is diversion specified instantly _{beforeWithdraw}if, due in t _{before Withdraw}, obtain this moment t _{before Withdraw}corresponding cycle average drift velocity proceed to step (5); If there is no due in t _before? _withdraw, then step (2) is returned;

(5) basis with the cycle average drift velocity after having withdrawn of being diversion expected computation period average drift velocity increment

$\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Withdraw}}={\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{after\; Withsraw}}\right)-{\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{before\; Withdraw}}\right)$

(6) according to cycle average drift velocity increment calculating is diversion and is withdrawn pulse at the component Δ v of passive space vehicle orbital coordinate system x-axis _x:

$\mathrm{\Δ}{v}_x=-\frac{1}{3}\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{withdraw}}$

Setting is diversion and is withdrawn pulse at the component Δ v of passive space vehicle orbital coordinate system z-axis _zfor:

In formula before withdrawing for being diversion, master control spacecraft is at the z-axis relative velocity component relative to passive space vehicle withdrawing pulse action point place that is diversion;

According to Δ v _xwith Δ v _zobtain being diversion and withdraw pulse size delta v _xzfor:

$\mathrm{\Δ}{v}_{\mathrm{xz}}=\sqrt{{\left(\mathrm{\Δ}{v}_x\right)}^2+{\left(\mathrm{\Δ}{v}_z\right)}^2};$

According to Δ v _xwith Δ v _zcalculate this to be diversion and to withdraw pulse relative to the pitching angle theta of passive space vehicle orbital coordinate system+x-axis _withdraw, wherein θ _withdraw=atan2 (-Δ v _z, Δ v _x); And specify this to be diversion to withdraw pulse it is 0 ° relative to the crab angle of passive space vehicle orbital coordinate system+x-axis;

(7) withdraw pulse action point place and apply to be diversion and to withdraw pulse being diversion completing is diversion withdraws control.

The orbital coordinate system of passive space vehicle is defined as: initial point C is positioned at passive space vehicle barycenter, and z-axis points to direction, the earth's core by passive space vehicle barycenter, and x-axis is vertical with z-axis and point to passive space vehicle heading, and y-axis and z-axis and x-axis meet right-hand rule.

When preparing to withdraw from passive space vehicle front, being diversion and withdrawing pulse action point selection at the oval some place crossing with passive space vehicle orbital coordinate system+x-axis of being diversion; When preparing to withdraw from passive space vehicle rear, being diversion and withdrawing pulse action point selection at the oval some place crossing with passive space vehicle orbital coordinate system-x-axis of being diversion.

The present invention's advantage is compared with prior art: for obtaining the situation of master control spacecraft relative to passive space vehicle station-keeping data continuously, directly at near-circular orbit passive space vehicle x coordinate direction, get the relative measurement data of two complete cycles, by after cycle summation again to summed result about passive space vehicle orbital period square do difference coefficient, provide the parameter that is referred to as cycle average drift velocity.It is firm that this parameter directly has speed amount, describes the average drift movement velocity of relative motion complete cycle configuration exactly.Set after formation retentive control completes as required or be diversion withdraw after the cycle average drift velocity expected, before this expectation drift velocity deducts control, cycle average drift velocity obtains cycle average drift velocity increment, dipulse and the horizontal component of withdrawing control monopulse of being diversion of formation retentive control obtain by this incremental computations, thus make formation retentive control have the features such as autonomous and low-frequency degree, making to be diversion, it is autonomous and safe and efficient to withdraw.

Accompanying drawing explanation

Fig. 1 is the FB(flow block) of the inventive method;

Fig. 2 is passive space vehicle orbital coordinate system definition schematic diagram;

Fig. 3 is passive space vehicle nodal coordinate system definition schematic diagram;

Fig. 4 is that master control Spacecraft formation maintains control dipulse application point schematic diagram;

Fig. 5 is be diversion the pulse action point and pulse orientation schematic diagram withdrawn.

Embodiment

As shown in Figure 1, Spacecraft formation of the present invention maintains control method, and step is as follows:

(1) when expecting that in follow-up a period of time, orbits controlling all can not occur for master control spacecraft and passive space vehicle, a sampling initial time t carrying out cycle average drift velocity calculating is specified ₀₀.

(2) cycle average drift velocity is carried out as follows calculating:

${\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t\right)=\frac{{\∫}_{t_0+T}^{t_0+2T}{x}_r\left(t\right)\mathrm{dt}-{\∫}_{t_0}^{t_0+T}{x}_r\left(t\right)\mathrm{dt}}{T^2}$

X in formula _rt () is the x-axis location components of master control spacecraft in the orbital coordinate system of passive space vehicle corresponding to sampling instant t, obtain according to measurement; As shown in Figure 2, the orbital coordinate system of passive space vehicle is defined as: initial point C is positioned at passive space vehicle barycenter, z-axis points to direction, the earth's core by passive space vehicle barycenter, and x-axis is vertical with z-axis and point to passive space vehicle heading, and y-axis and z-axis and x-axis meet right-hand rule; T is the passive space vehicle orbital period; t ₀for the integration initial time of previous orbital period in adjacent two orbital periods, t ₀value is:

$t_0=\left\{\begin{array}{cc}{t}_{00}& t\≤t_{00}+2T\\ t-2T& t>t_{00}+2T\end{array}\right.$

I.e. t ₀at t≤t ₀₀when+2T, equal value is t ₀₀, but t ₀from t>t ₀₀first point of+2T starts to slide on a timeline value, thus the slip on a timeline of average drift velocity performance period calculates.

(3) judge whether moment t meets t>t ₀₀+ 2T, when meeting t>t ₀₀during+2T, obtain the cycle average drift velocity result that first convergence is available, and proceed to step (4); Otherwise, return step (2).

(4) judge whether moment t arrives to form into columns to maintain instantly and control Startup time t _beforeKeepif, due in t _beforeKeep, obtain this moment t _beforeKeepcorresponding cycle average drift velocity proceed to step (5); If there is no due in t _beforeKeep, then step (2) is returned;

When the motion of master control spacecraft relative target spacecraft exceeds the specific interval range of passive space vehicle orbital coordinate system x-axis, think that moment t arrives to form into columns to maintain instantly and control Startup time t _beforeKeep, otherwise, think that moment t not yet arrives to form into columns to maintain instantly and control Startup time t _beforeKeep.

(5) according to cycle average drift velocity cycle average drift velocity after having controlled with the maintenance expected calculate the cycle average drift velocity increment of forming into columns and maintaining and controlling

$\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Keep}}={\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{after\; K\; eep}}\right)-{\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{before\; K\; eep}}\right)$

Reversal periods average drift velocity after the retentive control expected completes is according to form into columns with fly or be diversion configuration along passive space vehicle orbital coordinate system x-axis the circle time of specifying wish drift about distance determine, be known quantity.

(6) according to cycle average drift velocity increment calculating forms into columns maintains in level of control dipulse the formation component Δ v realizing the long adjustment of relative major semi-axis _a:

$\mathrm{\Δ}{v}_a=-\frac{1}{3}\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Keep}}$

(7) the relative eccentric ratio vector before controlling to implement is maintained according to forming into columns target relative eccentric ratio vector after having controlled with the maintenance expected calculate relative eccentric ratio delta vector

And determine relative eccentric ratio delta vector at passive space vehicle nodal coordinate system Ox _ny _nz _nmiddle x _naxle and y _nthe coordinate components δ Δ e of axle _xwith δ Δ e _y, namely at passive space vehicle nodal coordinate system Ox _ny _nz _nin have:

As shown in Figure 3, passive space vehicle nodal coordinate system Ox _ny _nz _nbe defined as: initial point Ο is the earth's core, axle x _npassive space vehicle ascending node of orbit is pointed to, axle z from Ο _nalong passive space vehicle orbital angular momentum vector direction, axle y _nwith z _naxle and x _naxle meets right-hand rule.

(8) according to formula calculate the amplitude δ Δ e of relative eccentric ratio delta vector; The formation component Δ v forming into columns and maintain and realize relative eccentric ratio adjustment in level of control dipulse is calculated according to the amplitude δ Δ e of relative eccentric ratio delta vector _e:

$\mathrm{\Δ}{v}_e=\frac{{\stackrel{\‾}{a}}_{t\arg \mathrm{et}}{n}_{t\arg \mathrm{et}}}{4}\mathrm{\δ\Δe}$

In formula for the flat major semi-axis of passive space vehicle is long, n _targetfor the track angular speed of passive space vehicle.

(9) according to Δ v _awith Δ v _edetermine the horizontal dipulse size maintaining and control of forming into columns, computing formula is:

$\mathrm{\Δ}{v}_{x1}=\frac{1}{2}\mathrm{\Δ}{v}_a+\mathrm{\Δ}{v}_e$

$\mathrm{\Δ}{v}_{x2}=\frac{1}{2}\mathrm{\Δ}{v}_a-\mathrm{\Δ}{v}_e$

Wherein, Δ v _x1be the size of the first pulse, Δ v _x2it is the size of the second pulse;

As Δ v _x1or Δ v _x2when being greater than 0, corresponding pulse action direction is consistent with passive space vehicle orbital coordinate system+x direction; As Δ v _x1or Δ v _x2when being less than 0, corresponding pulse action direction is contrary with passive space vehicle orbital coordinate system-x direction.

(10) according to δ Δ e _x, δ Δ e _ydetermine the track argument of horizontal dipulse application point on master control spacecraft:

u _x1＝atan2(δΔe _y,δΔe _x)

u _x2＝atan2(-δΔe _y,-δΔe _x)

Wherein, u _x1for the track argument of described first pulse application point on master control spacecraft, u _x2for the track argument of described second pulse application point on master control spacecraft, see Fig. 4; Atan2 ( ^★, ^★) the expansion codomain that is suitable for for engineering is to the arctan function of [-π, π] scope;

(11) at track argument u _x1place applies the first pulse Δ v to master control spacecraft _x1, at track argument u _x2place applies the second pulse Δ v to master control spacecraft _x2, completing forms into columns maintains control.

As shown in Figure 1, spacecraft of the present invention is diversion and withdraws control method, and step is as follows:

(1) when expecting that in follow-up a period of time, orbits controlling all can not occur for master control spacecraft and passive space vehicle, a sampling initial time t carrying out cycle average drift velocity calculating is specified ₀₀;

(2) cycle average drift velocity is carried out as follows calculating:

${\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t\right)=\frac{{\∫}_{t_0+T}^{t_0+2T}{x}_r\left(t\right)\mathrm{dt}-{\∫}_{t_0}^{t_0+T}{x}_r\left(t\right)\mathrm{dt}}{T^2}$

X in formula _rt () is the x-axis location components of master control spacecraft in the orbital coordinate system of passive space vehicle corresponding to sampling instant t, obtain according to measurement; As shown in Figure 2, the orbital coordinate system of passive space vehicle is defined as: initial point C is positioned at passive space vehicle barycenter, z-axis points to direction, the earth's core by passive space vehicle barycenter, and x-axis is vertical with z-axis and point to passive space vehicle heading, and y-axis and z-axis and x-axis meet right-hand rule; T is the passive space vehicle orbital period; t ₀for the integration initial time of previous orbital period in adjacent two orbital periods, t ₀value is:

$t_0=\left\{\begin{array}{cc}{t}_{00}& t\≤t_{00}+2T\\ t-2T& t>t_{00}+2T\end{array}\right.$

I.e. t ₀at t≤t ₀₀when+2T, equal value is t ₀₀, but t ₀from t>t ₀₀first point of+2T starts to slide on a timeline value, thus the slip on a timeline of average drift velocity performance period calculates;

(3) judge whether moment t meets t>t ₀₀+ 2T, when meeting t>t ₀₀during+2T, obtain the cycle average drift velocity result that first convergence is available, and proceed to step (4); Otherwise, return step (2);

(4) judge whether moment t arrives the departure time t that is diversion instantly _{beforeWithdraw}if, due in t _{beforeWithdraw}, obtain this moment t _{beforeWithdraw}corresponding cycle average drift velocity proceed to step (5); If there is no due in t _{beforeWithdraw}then return step (2);

Be diversion departure time t _{beforeWithdraw}for the known quantity of specifying;

(5) basis with the cycle average drift velocity after having withdrawn of being diversion expected calculating is diversion withdraws the cycle average drift velocity increment of control

$\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Withdraw}}={\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{after\; Withsraw}}\right)-{\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{before\; Withdraw}}\right)$

Wherein, the cycle average drift velocity after having withdrawn of being diversion expected for the known quantity of specifying;

(6) according to cycle average drift velocity increment calculating is diversion and is withdrawn pulse at the component Δ v of passive space vehicle orbital coordinate system x-axis _x:

$\mathrm{\Δ}{v}_x=-\frac{1}{3}\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Withdraw}}$

Setting is diversion and is withdrawn pulse at the component Δ v of passive space vehicle orbital coordinate system z-axis _zfor:

$\mathrm{\Δ}{v}_z=-{\stackrel{\·}{z}}_0$

In formula before withdrawing for being diversion, master control spacecraft is withdrawing the z-axis relative velocity component relative to passive space vehicle at pulse action point place; As shown in Figure 5, when preparing to withdraw from passive space vehicle front, being diversion and withdrawing pulse action point selection at the oval some place crossing with passive space vehicle orbital coordinate system+x-axis of being diversion; When preparing to withdraw from passive space vehicle rear, being diversion and withdrawing pulse action point selection at the oval some place crossing with passive space vehicle orbital coordinate system-x-axis of being diversion;

According to Δ v _xwith Δ v _zobtain being diversion and withdraw pulse size delta v _xzfor:

$\mathrm{\Δ}{v}_{\mathrm{xz}}=\sqrt{{\left(\mathrm{\Δ}{v}_x\right)}^2+{\left(\mathrm{\Δ}{v}_z\right)}^2}$

See Fig. 5, according to Δ v _xwith Δ v _zcalculate this to be diversion and to withdraw pulse relative to the pitching angle theta of passive space vehicle orbital coordinate system+x-axis _withdraw:

θ _Withdraw＝atan2(-Δv _z,Δv _x)

Atan2 ( ^★, ^★) the expansion codomain that is suitable for for engineering is to the arctan function of [-π, π] scope; And specify this to be diversion to withdraw pulse it is 0 ° relative to the crab angle of passive space vehicle orbital coordinate system+x-axis;

(7) apply to be diversion and to withdraw pulse withdrawing pulse action point place completing is diversion withdraws control.

The content be not described in detail in instructions of the present invention belongs to the known technology of those skilled in the art.

Claims (7)

1. Spacecraft formation maintains a control method, it is characterized in that step is as follows:

(1) when expecting that in follow-up a period of time, orbits controlling all can not occur for master control spacecraft and passive space vehicle, a sampling initial time t carrying out cycle average drift velocity calculating is specified ₀₀;

(2) cycle average drift velocity is carried out as follows calculating:

${\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t\right)=\frac{{\∫}_{t_0+T}^{t_0+2T}{x}_r\left(t\right)\mathrm{dt}-{\∫}_{t_0}^{t_0+T}{x}_r\left(t\right)\mathrm{dt}}{T^2}$

X in formula _rt () is the x-axis location components of master control spacecraft in the orbital coordinate system of passive space vehicle corresponding to sampling instant t, obtain according to measurement; T is the passive space vehicle orbital period; t ₀for the integration initial time of previous orbital period in adjacent two orbital periods, t ₀value is:

$t_0=\left\{\begin{array}{cc}{t}_{00}& t\≤t_{00}+2T\\ t-2T& t>t_{00}+2T\end{array}\right.;$

(3) judge whether moment t meets t>t ₀₀+ 2T, when meeting t>t ₀₀during+2T, obtain the cycle average drift velocity result that first convergence is available, and proceed to step (4); Otherwise, return step (2);

(4) judge whether moment t arrives to form into columns to maintain and control Startup time t _beforeKeepif, due in t _beforeKeep, obtain this moment t _beforeKeepcorresponding cycle average drift velocity proceed to step (5); If there is no due in t _beforeKeep, then step (2) is returned;

(5) according to cycle average drift velocity cycle average drift velocity after having controlled with the maintenance expected computation period average drift velocity increment

$\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Keep}}={\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{afterKeep}}\right)-{\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{beforeKeep}}\right)$

(6) according to cycle average drift velocity increment calculating forms into columns maintains in level of control dipulse the formation component Δ v realizing the long adjustment of relative major semi-axis _a:

${\mathrm{\Δv}}_a=-\frac{1}{3}\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Keep}}$

(7) the relative eccentric ratio vector before controlling to implement is maintained according to forming into columns target relative eccentric ratio vector after having controlled with the maintenance expected calculate relative eccentric ratio delta vector wherein and determine relative eccentric ratio delta vector at passive space vehicle nodal coordinate system Ox _ny _nz _nmiddle x _naxle and y _nthe coordinate components δ Δ e of axle _xwith δ Δ e _y;

(8) according to formula calculate the amplitude δ Δ e of relative eccentric ratio delta vector; The formation component Δ v forming into columns and maintain and realize relative eccentric ratio adjustment in level of control dipulse is calculated according to the amplitude δ Δ e of relative eccentric ratio delta vector _e:

${\mathrm{\Δv}}_e=\frac{{\stackrel{\‾}{a}}_{t\arg \mathrm{et}}{n}_{t\arg \mathrm{et}}}{4}\mathrm{\δ\Δe}$

In formula for the flat major semi-axis of passive space vehicle is long, n _targetfor the track angular speed of passive space vehicle;

(9) according to Δ v _awith Δ v _edetermine the horizontal dipulse size maintaining and control of forming into columns, computing formula is:

$\mathrm{\Δ}{v}_{x1}=\frac{1}{2}{\mathrm{\Δv}}_a+{\mathrm{\Δv}}_e,$

${\mathrm{\Δv}}_{x2}=\frac{1}{2}{\mathrm{\Δv}}_a-{\mathrm{\Δv}}_e,$

Wherein, Δ v _x1be the size of the first pulse, Δ v _x2it is the size of the second pulse;

(10) according to δ Δ e _x, δ Δ e _ydetermine the track argument of horizontal dipulse application point on master control spacecraft:

u _x1＝atan2(δΔe _y,δΔe _x)

u _x2＝atan2(-δΔe _y,-δΔe _x)

Wherein, u _x1for the track argument of described first pulse application point on master control spacecraft, u _x2for the track argument of described second pulse application point on master control spacecraft, the expansion codomain that atan2 (*, *) is suitable for for engineering is to the arctan function of [-π, π] scope;

(11) at track argument u _x1place applies the first pulse Δ v to master control spacecraft _x1, at track argument u _x2place applies the second pulse Δ v to master control spacecraft _x2, completing forms into columns maintains control.

2. Spacecraft formation according to claim 1 maintains control method, it is characterized in that, the orbital coordinate system of passive space vehicle is defined as: initial point C is positioned at passive space vehicle barycenter, z-axis points to direction, the earth's core by passive space vehicle barycenter, x-axis is vertical with z-axis and point to passive space vehicle heading, and y-axis and z-axis and x-axis meet right-hand rule.

3. Spacecraft formation according to claim 1 maintains control method, it is characterized in that, when the motion of master control spacecraft relative target spacecraft exceeds the specific interval range of passive space vehicle orbital coordinate system x-axis, think that moment t arrives to form into columns to maintain instantly and control Startup time t _beforeKeep, otherwise, think that moment t not yet arrives to form into columns to maintain instantly and control Startup time t _beforeKeep.

4. a kind of Spacecraft formation according to claim 1 maintains control method, and it is characterized in that, passive space vehicle nodal coordinate system is defined as: initial point Ο is the earth's core, axle x _npassive space vehicle ascending node of orbit is pointed to, axle z from Ο _nalong passive space vehicle orbital angular momentum vector direction, axle y _nwith z _naxle and x _naxle meets right-hand rule.

5. spacecraft is diversion and withdraws a control method, it is characterized in that step is as follows:

(1) when expecting that in follow-up a period of time, orbits controlling all can not occur for master control spacecraft and passive space vehicle, a sampling initial time t carrying out cycle average drift velocity calculating is specified ₀₀;

(2) cycle average drift velocity is carried out as follows calculating:

${\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t\right)=\frac{{\∫}_{t_0+T}^{t_0+2T}{x}_r\left(t\right)\mathrm{dt}-{\∫}_{t_0}^{t_0+T}{x}_r\left(t\right)\mathrm{dt}}{T^2}$

X in formula _rt () is the x-axis location components of master control spacecraft in the orbital coordinate system of passive space vehicle corresponding to sampling instant t, obtain according to measurement; T is the passive space vehicle orbital period; t ₀for the integration initial time of previous orbital period in adjacent two orbital periods, t ₀value is:

$t_0=\left\{\begin{array}{cc}{t}_{00}& t\≤t_{00}+2T\\ t-2T& t>t_{00}+2T\end{array}\right.;$

(3) judge whether moment t meets t>t ₀₀+ 2T, when meeting t>t ₀₀during+2T, obtain the cycle average drift velocity result that first convergence is available, and proceed to step (4); Otherwise, return step (2);

(4) judge whether moment t arrives the departure time t that is diversion specified instantly _{beforeWithdraw}if, due in t _{beforeWithdraw}, obtain this moment t _{beforeWithdraw}corresponding cycle average drift velocity proceed to step (5); If there is no due in t _{beforeWithdraw}, then step (2) is returned;

(5) basis with the cycle average drift velocity after having withdrawn of being diversion expected computation period average drift velocity increment

$\mathrm{\Δ}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Withdraw}}={\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{afterWithdraw}}\right)-{\stackrel{\‾}{V}}_{\mathrm{drift}}\left(t_{\mathrm{beforeWithdraw}}\right)$

(6) according to cycle average drift velocity increment calculating is diversion and is withdrawn pulse at the component Δ v of passive space vehicle orbital coordinate system x-axis _x:

${\mathrm{\Δv}}_x=-\frac{1}{3}{\stackrel{\‾}{V}}_{\mathrm{drift},\mathrm{Withdraw}}$

Setting is diversion and is withdrawn pulse at the component Δ v of passive space vehicle orbital coordinate system z-axis _zfor:

${\mathrm{\Δv}}_z=-{\stackrel{\·}{z}}_0$

In formula before withdrawing for being diversion, master control spacecraft is at the z-axis relative velocity component relative to passive space vehicle withdrawing pulse action point place that is diversion;

According to Δ v _xwith Δ v _zobtain being diversion and withdraw pulse size delta v _xzfor:

${\mathrm{\Δv}}_{\mathrm{xz}}=\sqrt{{\left({\mathrm{\Δv}}_x\right)}^2+{\left({\mathrm{\Δv}}_z\right)}^2};$

According to Δ v _xwith Δ v _zcalculate this to be diversion and to withdraw pulse relative to the pitching angle theta of passive space vehicle orbital coordinate system+x-axis _withdraw, wherein θ _withdraw=atan2 (-Δ v _z, Δ v _x); And specify this to be diversion to withdraw pulse it is 0 ° relative to the crab angle of passive space vehicle orbital coordinate system+x-axis;

(7) withdraw pulse action point place and apply to be diversion and to withdraw pulse being diversion completing is diversion withdraws control.

6. spacecraft according to claim 5 is diversion and withdraws control method, it is characterized in that, the orbital coordinate system of passive space vehicle is defined as: initial point C is positioned at passive space vehicle barycenter, z-axis points to direction, the earth's core by passive space vehicle barycenter, x-axis is vertical with z-axis and point to passive space vehicle heading, and y-axis and z-axis and x-axis meet right-hand rule.

7. spacecraft according to claim 5 is diversion and withdraws control method, it is characterized in that, when preparing to withdraw from passive space vehicle front, being diversion and withdrawing pulse action point selection at the oval some place crossing with passive space vehicle orbital coordinate system+x-axis of being diversion; When preparing to withdraw from passive space vehicle rear, being diversion and withdrawing pulse action point selection at the oval some place crossing with passive space vehicle orbital coordinate system-x-axis of being diversion.