CN114889849A - Estimation method for multi-constraint flying-over optimal speed of spacecraft - Google Patents
Estimation method for multi-constraint flying-over optimal speed of spacecraft Download PDFInfo
- Publication number
- CN114889849A CN114889849A CN202210737971.9A CN202210737971A CN114889849A CN 114889849 A CN114889849 A CN 114889849A CN 202210737971 A CN202210737971 A CN 202210737971A CN 114889849 A CN114889849 A CN 114889849A
- Authority
- CN
- China
- Prior art keywords
- flying
- spacecraft
- speed
- constraint
- velocity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 16
- 238000012546 transfer Methods 0.000 claims abstract description 7
- 238000012937 correction Methods 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims description 4
- 230000008859 change Effects 0.000 claims description 3
- 238000006073 displacement reaction Methods 0.000 claims description 3
- 230000007774 longterm Effects 0.000 claims description 3
- 239000011159 matrix material Substances 0.000 claims description 3
- 230000008685 targeting Effects 0.000 claims description 3
- 238000005457 optimization Methods 0.000 abstract description 7
- 238000013461 design Methods 0.000 abstract description 4
- 238000007689 inspection Methods 0.000 abstract description 3
- 230000006870 function Effects 0.000 description 4
- 230000007704 transition Effects 0.000 description 3
- 230000008447 perception Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000012634 optical imaging Methods 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64G—COSMONAUTICS; VEHICLES OR EQUIPMENT THEREFOR
- B64G1/00—Cosmonautic vehicles
- B64G1/22—Parts of, or equipment specially adapted for fitting in or to, cosmonautic vehicles
- B64G1/24—Guiding or controlling apparatus, e.g. for attitude control
- B64G1/242—Orbits and trajectories
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Engineering & Computer Science (AREA)
- Remote Sensing (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Radar, Positioning & Navigation (AREA)
- Aviation & Aerospace Engineering (AREA)
- Navigation (AREA)
- Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
Abstract
The invention discloses a method for estimating the optimal speed of multi-constraint flying of a spacecraft, which comprises the following steps: s1, establishing a terminal inequality constraint expression of the fly-by patrol; s2, calculating the optimal flying time and the plane orientation of the flying orbit according to the orbital out-of-plane degree of the spacecraft and the target; and S3, giving an initial value of the flying speed according to the flying orbital plane orientation, and establishing a multi-constraint flying optimal speed estimation in fixed time based on the Cohen-Tack condition. The method sets the magnitude and three direction components of the tail end flying speed as 4 unknowns, designs an objective function of an optimization problem as a speed increment under a single pulse, introduces 3 inequality constraints including a flying inspection sunlight angle, a flying relative speed and a track near-location height during flying, lists an 8-dimensional equation set by using a Cohen-Tack condition, obtains a flying optimal speed estimation, changes the flying estimation into a rendezvous estimation, and estimates the transfer cost by using a known track root number difference.
Description
Technical Field
The invention relates to the technical field of estimation of a spacecraft flying state, in particular to a method for estimating the optimal speed of multi-constraint flying of a spacecraft.
Background
With the construction of low-orbit giant constellations such as satellite chain satellites and the like, the on-orbit targets in the near-earth space are increased sharply, and the satellite group shielding the sun presents a serious challenge to the perception capability of the future space situation. Due to the development of space-based optical imaging technology, a spatial situation perception system based on a satellite provided with an optical sensor is further emphasized. The multi-spacecraft is utilized to perform out-of-plane flying, the flying can be approached to and a plurality of target satellites can be shot in a short time at a low fuel cost, so that image data of constellation satellites, formation satellites and other cluster satellites can be quickly obtained, and support is provided for subsequent task decision.
In studying one-to-many, many-to-many fly-by patrol sequence problems, efficient single-pair single-fly-by cost estimation is needed to support. In the intersection estimation problem, since the position speeds of the beginning and the end are known, the transfer cost at the corresponding time can be estimated according to the track root number difference. However, in the fly-by mission, since the terminal speed is unknown, the optimal fly-by speed satisfying the terminal speed constraint needs to be estimated, so that the whole fly-by transition cost is minimum, and therefore, estimating the fly-by mission cost under the condition that the fly-by terminal speed cannot be determined in advance is a technical problem to be solved at present.
Disclosure of Invention
The invention aims to provide a method for estimating the optimal speed of multi-constraint flying of a spacecraft, so as to overcome the defects in the prior art.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a method for estimating the optimal speed of multi-constraint flying of a spacecraft comprises the following steps:
s1, establishing a terminal inequality constraint expression of the fly-by patrol;
s2, calculating the optimal flying time and the plane orientation of the flying orbit according to the orbital out-of-plane degree of the spacecraft and the target;
and S3, giving an initial value of the flying speed according to the flying orbital plane orientation, and establishing a multi-constraint flying optimal speed estimation in fixed time based on the Cohen-Tack condition.
Further, the step S1 is specifically:
setting the starting time t of the spacecraft under the geocentric inertial coordinate system 0 And a position velocity at the time of flight t is [ r ] C0 ,v C0 ]And [ r C ,v C ]And the target is at the starting time t 0 And a position velocity at the time of flight t is [ r ] T0 ,v T0 ]And [ r T ,v T ]Setting the flying task as non-deviation flying with position coincidence and speed deviation; the motion of the spacecraft and the target in the set time period before the flying is set to be uniform and linear, so that the relative position vector delta r of the spacecraft and the target can be deduced to be r T –r C With relative velocity vector δ v ═ v T –v C The cross product of (a) is 0, and the sight line direction before the position coincidence is replaced by delta v; setting a sight line direction and a sun position vector r S The lower limit of the included angle of the direction is alpha smin The constraint expression on the viewing sun angle is obtained as follows:
arccos((r S /r S )·(δv/δv))-(π-α smin )≤0 (36)
setting the relative speed of the spacecraft in flying not to exceed the upper limit delta v max :
δv-δv max ≤0 (37)
Setting the height of the near point of the spacecraft in flying to be not lower than the lower limit r pmin :
r pmin -a C (1-e C )≤0 (38)
In the formula, a C And e C The semi-major axis and eccentricity of the spacecraft at the moment of flight t.
Further, the step S2 specifically includes the following steps:
s20, setting the spacecraft at the starting time t 0 And the number of tracks at the time of flight t is [ a ] C0 ,e C0 ,i C0 ,Ω C0 ,ω C0 ,M C0 ]And [ a ] C ,e C ,i C ,Ω C ,ω C ,M C ]And the target is at the starting time t 0 And the number of tracks at the time of flight t is [ a ] T0 ,e T0 ,i T0 ,Ω T0 ,ω T0 ,M T0 ]And [ a ] T ,e T ,i T ,Ω T ,ω T ,M T ]A, e, i, omega, M are respectively a semi-major axis, eccentricity, inclination, elevation intersection declination, near arch point latitude argument and near point angle, subscripts C0 and C are the space vehicle at t 0 And the number of tracks at time T, subscripts T0 and T targeting at T 0 And the number of tracks at time t, the track transfer duration Deltat being t-t 0 Calculating out the heterozygosity phi of the two initial orbital planes and the maximum heterozygosity phi allowed by the relative speed constraint according to a spherical triangle formula max Comprises the following steps:
in the formula, mu is the universal gravitation constant of the central celestial body;
s21, when phi is less than or equal to phi max The spacecraft allows flying through the target by coplanar maneuvers only, where the optimal flying time Δ t opt The expression of (a) is:
in the formula u T Phase, u, of the initial orbital plane intersection of the spacecraft and the target on the target orbit T0 An initial phase of the target, k being a non-negative integer, u T The expression of (a) is:
in the formula u T There are two solutions, only the solution on the side of the shadow,andaiming at considering only J 2 The orbit root precession rate under the long-term perturbation comprises the expression of the orbit root precession rate including a spacecraft:
in the formula, J 2 Is a perturbation term constant, R E Is the earth's average equatorial radius;
s22, according to phi and phi max And Δ t opt Determining a unit normal vector h of the flying-over orbital plane e The threshold value of the time deviation is delta t threshold When phi is less than or equal to phi max And | Δ t- Δ t opt |≤Δt threshold Considering that the spacecraft can perform coplanar maneuver, the angular edge (i) in the spherical triangle is used C0 -i T0 -u T ) Solving the elevation difference delta omega of the elevation intersection point as follows:
when phi is less than or equal to phi max And | Δ t- Δ t opt |>Δt threshold Or phi>φ max In time, the spacecraft needs to be maneuvered to orbit in different planes according to the corner angle (i) in the spherical triangle T0 -u T -φ max ) To solve for the inclination i C And the rise-crossing point declination difference delta omega is:
according to Δ Ω ═ Ω T0 –Ω C Thereby obtaining a unit normal vector h e Is composed of
Further, the step S3 specifically includes the following steps:
s30, establishing O, r with the target as the origin T The direction being the x-axis, h e Setting the flying speed with respect to a coordinate system of LVLH with the direction of the z-axisMagnitude and three directional components of v C ,γ x ,γ y ,γ z Velocity vector v C And h e Orthogonal, magnitude of flying velocity v C In the xOy plane, the magnitude v of the flying speed is set C The included angle between the positive direction of the y axis is theta epsilon-theta max ,θ max ],θ max For boundary values of the angle, the three directional components of the velocity can be described by θ by the coordinate system change as:
in the formula (I), the compound is shown in the specification,a rotation matrix from an LVLH coordinate system to a geocentric inertia coordinate system;
the magnitude of the velocity is deduced according to the displacement formula of the position velocity and the number of the tracks C Expression (c):
in the formula, e Cmax Is the allowable upper limit of the eccentricity of the fly-over orbit;
by discrete v C And the value of theta in the respective upper and lower bounds, and the guess value is:
in the formula, N 1 And N 2 For the number of discrete points, α and β are both integers, and θ is guess Carrying in formula (11) to obtain a guess initial value of the direction;
s31, if the set flying trace is estimated by a single pulse, the number of orbit deviations caused by the single pulse are:
the magnitude of the velocity increment Δ v of a single pulse is:
in the formula (I), the compound is shown in the specification,the average orbit speed of the spacecraft at the initial moment is taken as the average orbit speed;
taking the square of the speed increment as an objective function of the optimal problem, the expression is as follows:
since the modulus values in the three unit directions of velocity are 1, the equality constraint is introduced as:
establishing a Lagrange equation, wherein the expression is as follows:
L=f+λ T g+κ T σ (53)
in the formula, λ is an equality constraint multiplier, κ is an inequality constraint multiplier, and according to the kun-tak condition, the partial derivatives of the four unknowns are solved, so that an 8-dimensional equality equation set is obtained:
in the formula, relate to a C ,e C ,i C ,Ω C ,ω C For v C ,γ x ,γ y ,γ z The partial derivatives of (2) are expressed by the number of the tracks in terms of position and velocity, and are recorded in terms of h C =[h Cx ,h Cy ,h Cz ] T ,e C =[e Cx ,e Cy ,e Cz ] T The expression is:
wherein h is C For the angular momentum of the fly-over orbit, let γ ═ γ x ,γ y ,γ z ] T The partial derivatives can be derived as:
note i x =[1,0,0] T ,i y =[0,1,0] T ,i z =[0,0,1] T Angular momentum vector h C And its modulus value h C About v C The partial derivatives of γ are:
relative velocity vector δ v and its modulus value δ v with respect to v C The partial derivatives of γ are:
eccentricity vector e C About v C The partial derivatives of γ are:
based on the initial value [ v ] of the flying speed given in step S3 C ,γ x ,γ y ,γ z ] 0 And the initial values of the equality constraint and inequality constraint multipliers [ lambda, kappa ] 1 ,κ 2 ,κ 3 ] 0 When the flying speed is 0, a Powell-based mixed numerical value iterator iterates to obtain a final flying speed solution;
s32, obtaining the final flying speed solution, generating a phase difference
Wherein u is Cf Extrapolating the phase of the spacecraft to the moment of flight for the spacecraft,andfor precession of spacecraft with respect to no maneuveringRate deviation, a first order approximation of the relative average angular velocity, can be obtained:
the phase correction is carried out by using the semimajor axis deviation, so that the delta u + delta n C Δ t is 0, and the modified semimajor axis expression is:
wherein N ∈ [ -1,1] represents the number of turns, and the magnitude of the flying speed after correction is as follows:
S33, converting the flying cost estimation into a rendezvous cost estimation, and estimating according to a rendezvous estimation algorithm;
s34, repeating the steps S30-S33, counting the speed increment delta v generated by each iteration, and selecting the minimum value to be recorded as delta v best The corresponding fly-over velocity is solved as [ v C ,γ x ,γ y ,γ z ] best 。
Compared with the prior art, the invention has the advantages that: the invention provides a method for estimating the optimal speed of multi-constraint flying of a spacecraft, which is characterized in that the size and three direction components of the tail end flying speed are set as 4 unknowns, the objective function of the design optimization problem is the speed increment under a single pulse, 3 inequality constraints including the sun angle of flying inspection, the relative speed of flying and the altitude of the orbit near place during flying are introduced, an 8-dimensional equation set is listed by utilizing the Kuen-Tack condition, the optimal speed estimation of flying is obtained by solving the equation set, the flying estimation is changed into intersection estimation, and therefore the transfer cost is estimated by utilizing the known orbit root number difference.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a line-of-sight solar angle constraint schematic diagram of the spacecraft in the flying time of the invention.
FIG. 2 is a flow chart of the method for estimating the multi-constraint flying optimal speed of the spacecraft.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, and the scope of the present invention will be more clearly and clearly defined.
Referring to fig. 1 and fig. 2, the embodiment discloses a method for estimating a multi-constraint flying optimal speed of a spacecraft, which includes the following steps:
and step S1, establishing a terminal inequality constraint expression for the fly-by patrol.
Specifically, the starting time t of the spacecraft under the geocentric inertial coordinate system is set 0 And a position velocity at the time of flight t is [ r ] C0 ,v C0 ]And [ r C ,v C ]And the target is at the starting time t 0 And a position velocity at the time of flight t is [ r ] T0 ,v T0 ]And [ r T ,v T ]Setting the flying task as non-deviation flying with position coincidence and speed deviation; the motion of the spacecraft and the target in the set time period before the flying is set to be uniform and linear, so that the relative position vector delta r of the spacecraft and the target can be deduced to be r T –r C With relative velocity vector δ v ═ v T –v C Cross product of (d) is 0 and δ v is used to replace the view before the position coincidenceA line direction; setting a sight line direction and sun position vector r S The lower limit of the included angle of the direction is alpha smin The constraint expression on the viewing sun angle is obtained as follows:
arccos((r S /r S )·(δv/δv))-(π-α smin )≤0 (71)
setting the relative speed of the spacecraft in flying not to exceed the upper limit delta v max :
δv-δv max ≤0 (72)
Setting the height of the near point of the spacecraft in flying to be not lower than the lower limit r pmin :
r pmin -a C (1-e C )≤0 (73)
In the formula, a C And e C The semi-major axis and eccentricity of the spacecraft at the moment of flight t.
And step S2, calculating the optimal flying time and the plane orientation of the flying orbit according to the orbital out-of-plane degree of the spacecraft and the target.
Specifically, step S2 includes the following steps:
step S20, setting the spacecraft at the starting time t 0 And the number of tracks at the time of flight t is [ a ] C0 ,e C0 ,i C0 ,Ω C0 ,ω C0 ,M C0 ]And [ a ] C ,e C ,i C ,Ω C ,ω C ,M C ]And the target is at the starting time t 0 And the number of tracks at the time of flight t is [ a ] T0 ,e T0 ,i T0 ,Ω T0 ,ω T0 ,M T0 ]And [ a ] T ,e T ,i T ,Ω T ,ω T ,M T ]A, e, i, omega, M are respectively a semi-major axis, eccentricity, inclination, elevation intersection declination, near arch point latitude argument and near point angle, subscripts C0 and C are the space vehicle at t 0 And the number of tracks at time T, subscripts T0 and T targeting at T 0 And the number of tracks at time t, the track transfer duration Deltat being t-t 0 Calculating out the heterozygosity phi of the two initial orbital planes and the maximum heterozygosity phi allowed by the relative speed constraint according to a spherical triangle formula max Comprises the following steps:
wherein mu is the gravitational constant of the central celestial body.
Step S21, when phi is less than or equal to phi max The spacecraft allows flying through the target by coplanar maneuvers only, where the optimal flying time Δ t opt The expression of (a) is:
in the formula u T Phase, u, of the initial orbital plane intersection of the spacecraft and the target on the target orbit T0 An initial phase of the target, k being a non-negative integer, u T The expression of (a) is:
in the formula u T There are two solutions, only the solution on the side of the shadow,andaiming at considering only J 2 The orbit root precession rate under the long-term perturbation comprises the expression of the orbit root precession rate including a spacecraft:
in the formula, J 2 Is a perturbation term constant, R E Is the average equatorial radius of the earth.
Step S22, according to phi and phi max And Δ t opt Determining a unit normal vector h of the flying-over orbital plane e The threshold value of the time deviation is delta t threshold When phi is less than or equal to phi max And | Δ t- Δ t opt |≤Δt threshold Considering that the spacecraft can perform coplanar maneuver, the angular edge (i) in the spherical triangle is used C0 -i T0 -u T ) Solving the elevation difference delta omega of the elevation intersection point as follows:
when phi is less than or equal to phi max And | Δ t- Δ t opt |>Δt threshold Or phi>φ max In time, the spacecraft needs to be maneuvered to orbit in different planes according to the corner angle (i) in the spherical triangle T0 -u T -φ max ) To solve for the inclination i C And the rise-crossing point declination difference delta omega is:
according to Δ Ω ═ Ω T0 –Ω C Thereby obtaining a unit normal vector h e Is composed of
And step S3, an initial value of the flying speed is given according to the flying orbital plane orientation, and a multi-constraint flying optimal speed estimation under fixed time is established based on the Cohen-Tack condition.
Specifically, step S3 specifically includes the following steps:
step S30, establishing O, r with the target as the origin T The direction being the x-axis, h e Setting the magnitude of the flying speed and three directional components as v in a relative coordinate system of the LVLH with the direction as a z-axis C ,γ x ,γ y ,γ z Velocity vector v C And h e Orthogonal, magnitude of flying velocity v C In the xOy plane, the magnitude v of the flying speed is set C The included angle theta and the positive direction of the y axis is epsilon[-θ max ,θ max ],θ max For boundary values of the angle, the three directional components of the velocity can be described by θ by the coordinate system change as:
in the formula (I), the compound is shown in the specification,a rotation matrix from an LVLH coordinate system to a geocentric inertia coordinate system;
the magnitude of the velocity is deduced according to the displacement formula of the position velocity and the number of the tracks C Expression (c):
in the formula, e Cmax Is the allowable upper limit of the eccentricity of the fly-over orbit;
by discrete v C And the value of theta in the respective upper and lower bounds, and the guess value is:
in the formula, N 1 And N 2 For the number of discrete points, α and β are both integers, and θ is guess Carrying in formula (11) to obtain a guess initial value of the direction;
step S31, if the estimated flying trace is set by a single pulse, the number of orbit deviations caused by the single pulse are:
the magnitude of the velocity increment Δ v of a single pulse is:
in the formula,. DELTA.v a =0.5v C0 Δa/a C0 ,Δv i =v C0 Δi,Δv Ω =v C0 ΔΩsini C0 ,v C0 The average orbit speed of the spacecraft at the initial moment is taken as the average orbit speed;
taking the square of the speed increment as an objective function of the optimal problem, the expression is as follows:
since the modulus values in the three unit directions of velocity are 1, the equality constraint is introduced as:
establishing a Lagrange equation, wherein the expression is as follows:
L=f+λ T g+κ T σ (88)
in the formula, λ is an equality constraint multiplier, κ is an inequality constraint multiplier, and according to the kun-tak condition, the partial derivatives of the four unknowns are solved, so that an 8-dimensional equality equation set is obtained:
in the formula, relate to a C ,e C ,i C ,Ω C ,ω C For v C ,γ x ,γ y ,γ z The partial derivatives of (2) are expressed by the number of the tracks in terms of position and velocity, and are recorded in terms of h C =[h Cx ,h Cy ,h Cz ] T ,e C =[e Cx ,e Cy ,e Cz ] T The expression is:
wherein h is C For the angular momentum of the fly-over orbit, let γ ═ γ x ,γ y ,γ z ] T The partial derivatives can be derived as:
note i x =[1,0,0] T ,i y =[0,1,0] T ,i z =[0,0,1] T Angular momentum vector h C And its modulus value h C About v C The partial derivatives of γ are:
relative velocity vector δ v and its modulus value δ v with respect to v C And the partial derivatives of γ are:
eccentricity vector e C About v C The partial derivatives of γ are:
based on the initial value [ v ] of the flying speed given in step S3 C ,γ x ,γ y ,γ z ] 0 And the initial values of the equality constraint and inequality constraint multipliers [ lambda, kappa ] 1 ,κ 2 ,κ 3 ] 0 A final solution to the speed of flight can be obtained by iterating a Powell-based mixed-value iterator Minpack-1 [ More j.j., garhow b.s., and hillboom k.e.user guide for Minpack-1.Argonne National lab.rept.anl-80-74, Illinois,1980 ].
After the final fly-over velocity solution is obtained in step S32, a phase difference is generated
Wherein u is Cf Extrapolating the phase of the spacecraft to the moment of flight for the spacecraft,andis a spacecraft havingThe deviation of precession rate when maneuvering is relative to that when no maneuvering, the relative average angular velocity is approximated to the first order, and the following can be obtained:
the phase correction is carried out by using the semimajor axis deviation, so that the delta u + delta n C Δ t is 0, and the modified semimajor axis expression is:
wherein N ∈ [ -1,1] represents the number of turns, and the magnitude of the flying speed after correction is as follows:
Step S33, when the terminal speed is obtained, the fly-over cost estimation is converted into the rendezvous cost estimation, and the estimation is carried out according to the rendezvous estimation algorithm, the rendezvous estimation algorithm can refer to the existing mature perturbation rendezvous estimation algorithm (Luoya, Huangsho Ying, Lihengzheng, Wushenggai, Zhang-in, and Populan) 2 Method for quickly estimating optimal speed increment of long-time rail crossing under perturbation [ P ]]The province of Hunan province: CN110789739B,2020-12-11.
Step S34, repeating steps S30-S33, counting the speed increment delta v generated in each iteration, and selecting the minimum value to be recorded as delta v best The corresponding fly-over velocity is solved as [ v C ,γ x ,γ y ,γ z ] best . As shown in the flow chart of fig. 2.
The invention is further described below by way of examples.
1) Establishing an inequality constraint expression of a terminal for fly-by patrol;
given alpha smin Given as 30deg, δ v max 2km/s, given r pmin =6600km。
2) And calculating the optimal flying time and the plane azimuth of the flying orbit according to the orbital out-of-plane degree of the spacecraft and the target.
2.1) recording the initial epoch as t 0 59274MJD shows the number of orbits of the spacecraft and target at the initial moment in table 1:
TABLE 1 spacecraft and target at t 0 59274MJD orbit number
According to the spherical triangle formula, the heterosurface degree phi of the two initial orbital planes is calculated to be 2.349deg, and the maximum heterosurface degree phi is calculated max =15.298deg。
2.2) setting the number of flying turns k to 11, and the optimal flying time delta t opt 68731.86s, the fly-by transition time Δ t is given 68731.86 s.
2.3) according to phi and phi max And Δ t opt Determining a unit normal vector h of the flying-over orbital plane e =[0.12908,-0.52305,0.84247] T 。
3) And giving an initial value of the flying speed according to the flying orbital plane azimuth, and establishing multi-constraint flying optimal speed estimation in fixed time based on the Cohen-Tack condition.
3.1) given θ max =1.5deg,e Cmax 0.02,. multidot.v Cmax =7.57km/s,v Cmin 7.42 km/s. Setting the value step length of theta to be 0.5deg, then N 2 7; v. the C The step length of the value of (1) is 0.01km/s, then N 1 15. Alpha and beta are both 0, and the initial value of the first flying speed is [ v C ,γ x ,γ y ,γ z ] 0 =[7.425,0.464,0.783,0.415]。
3.2) iterating the initial velocity value by using a Minpack-1 solver according to the established 8-dimensional equation set to obtain an iteration value [ v ] of the flying velocity C ,γ x ,γ y ,γ z ]=[7.500,0.436,0.877,0.204]。
3.3) the phase difference produced at this speed is 96.085 DEG, and a new flying speed is obtained by trimming with a magnitude of v C =7.446km/s。
3.4) obtaining the flying speed, estimating the transition cost according to the orbit root difference between the new tail end flying state and the initial state of the spacecraft, and obtaining the corresponding speed increment delta v which is 215.6 m/s.
3.5) circularly taking values for 105 times, sequentially executing the steps 3.1) to 3.4), and taking the solution of the minimum delta v as the optimal flying speed [ v C ,γ x ,γ y ,γ z ] best And an optimum velocity increment Δ v best . In order to compare the accuracy and the efficiency of the algorithm, a differential evolution algorithm is adopted to carry out 3-pulse fly-by trajectory optimization on the same example, and the final optimization and estimation results and relative errors are shown in a table 2:
TABLE 2 fly-by estimation versus optimization of differential evolution algorithm
In the table, the relative error of 4 variables of the optimized flying speed is small, the maximum is not more than 5%, and the corresponding speed increment error is not more than 8%, so the precision of the estimation algorithm is considerable.
In optimization time, the 3-pulse flying track has 9 design variables, the population of a differential evolution algorithm is set as 108, the evolution algebra is 200, the number of parallel kernels is 6, and the average time for 20-time operation is 15 s; the algorithm provided by the invention only needs about 0.001s for each cycle, and needs about 0.1s for 105 times of operation, which is two orders of magnitude less than that of the differential algorithm.
The method sets the magnitude and three direction components of the tail end flying speed as 4 unknowns, designs an objective function of an optimization problem as a speed increment under a single pulse, introduces 3 inequality constraints including a flying inspection sunlight angle, a flying relative speed and a track near-location height during flying, lists an 8-dimensional equation set by using a Cohn-Tack condition, obtains a flying optimal speed estimation by solving the equation set, changes the flying estimation into a rendezvous estimation, and estimates the transfer cost by using a known track root number difference.
Although the embodiments of the present invention have been described with reference to the accompanying drawings, various changes or modifications may be made by the patentees within the scope of the appended claims, and within the scope of the invention, as long as they do not exceed the scope of the invention described in the claims.
Claims (4)
1.A method for estimating the optimal speed of multi-constraint flying of a spacecraft is characterized by comprising the following steps:
s1, establishing a terminal inequality constraint expression of the fly-by patrol;
s2, calculating the optimal flying time and the plane orientation of the flying orbit according to the orbital out-of-plane degree of the spacecraft and the target;
and S3, giving an initial value of the flying speed according to the flying orbital plane orientation, and establishing a multi-constraint flying optimal speed estimation in fixed time based on the Cohen-Tack condition.
2. The method for estimating the multi-constraint flying optimal speed of the spacecraft of claim 1, wherein the step S1 specifically comprises:
setting the starting time t of the spacecraft under the geocentric inertial coordinate system 0 And a position velocity at the time of flight t is [ r ] C0 ,v C0 ]And [ r C ,v C ]And the target is at the starting time t 0 And a position velocity at the time of flight t is [ r ] T0 ,v T0 ]And [ r T ,v T ]Setting the flying task as non-deviation flying with position coincidence and speed deviation; the motion of the spacecraft and the target in the set time period before the flying is set to be uniform and linear, so that the relative position vector delta r of the spacecraft and the target can be deduced to be r T –r C With relative velocity vector δ v ═ v T –v C The cross product of (a) is 0, and the sight line direction before the position coincidence is replaced by delta v; setting a sight line direction and sun position vector r S The lower limit of the included angle of the direction is alpha smin The constraint expression on the viewing sun angle is obtained as follows:
arccos((r S /r S )·(δv/δv))-(π-α smin )≤0 (1)
setting the relative speed of the spacecraft in flying not to exceed the upper limit delta v max :
δv-δv max ≤0 (2)
Setting the height of the near point of the spacecraft in flying to be not lower than the lower limit r pmin :
r pmin -a C (1-e C )≤0 (3)
In the formula, a C And e C The semi-major axis and eccentricity of the spacecraft at the moment of flight t.
3. The method for estimating multi-constraint flyover optimal speed of a spacecraft according to claim 1, wherein the step S2 specifically comprises the following steps:
s20, setting the spacecraft at the starting time t 0 And the number of tracks at the time of flight t is [ a ] C0 ,e C0 ,i C0 ,Ω C0 ,ω C0 ,M C0 ]And [ a ] C ,e C ,i C ,Ω C ,ω C ,M C ]And the target is at the starting time t 0 And the number of tracks at the time of flight t is [ a ] T0 ,e T0 ,i T0 ,Ω T0 ,ω T0 ,M T0 ]And [ a ] T ,e T ,i T ,Ω T ,ω T ,M T ]A, e, i, omega, M are respectively a semi-major axis, eccentricity, inclination, elevation intersection declination, near arch point latitude argument and near point angle, subscripts C0 and C are the space vehicle at t 0 And the number of tracks at time T, subscripts T0 and T targeting at T 0 And the number of tracks at time t, the track transfer duration Deltat being t-t 0 Calculating out the heterozygosity phi of the two initial orbital planes and the maximum heterozygosity phi allowed by the relative speed constraint according to a spherical triangle formula max Comprises the following steps:
in the formula, mu is the universal gravitation constant of the central celestial body;
s21, when phi is less than or equal to phi max The spacecraft allows flying over the target by coplanar maneuvers only, at which time the optimal flying time Δ t opt The expression of (a) is:
in the formula u T Phase, u, of the initial orbital plane intersection of the spacecraft and the target on the target orbit T0 An initial phase of the target, k being a non-negative integer, u T The expression of (a) is:
in the formula u T There are two solutions, only the solution on the side of the shadow,andaiming at considering only J 2 The orbit root precession rate under the long-term perturbation comprises the expression of the orbit root precession rate including a spacecraft:
in the formula, J 2 Is a perturbation term constant, R E Is the earth's average equatorial radius;
s22, according to phi and phi max And Δ t opt Determining a unit normal vector h of the flying-over orbital plane e Time biasThe threshold value of the difference is Δ t threshold When phi is less than or equal to phi max And | Δ t- Δ t opt |≤Δt threshold Considering that the spacecraft can perform coplanar maneuver, the angular edge (i) in the spherical triangle is used C0 -i T0 -u T ) Solving the elevation difference delta omega of the elevation intersection point as follows:
when phi is less than or equal to phi max And | Δ t- Δ t opt |>Δt threshold Or phi>φ max In time, the spacecraft needs to be maneuvered to orbit in different planes according to the corner angle (i) in the spherical triangle T0 -u T -φ max ) To solve for the inclination i C And the rise-crossing point declination difference delta omega is:
according to Δ Ω ═ Ω T0 –Ω C Thereby obtaining a unit normal vector h e Is composed of
4. The method for estimating multi-constraint flying optimal speed of a spacecraft according to claim 1, wherein the step S3 specifically comprises the following steps:
s30, establishing O, r with the target as the origin T The direction being the x-axis, h e Setting the magnitude of the flying speed and three directional components as v in a relative coordinate system of the LVLH with the direction as a z-axis C ,γ x ,γ y ,γ z Velocity vector v C And h e Orthogonal, magnitude of flying velocity v C In the xOy plane, the magnitude v of the flying speed is set C The included angle between the positive direction of the y axis is theta epsilon-theta max ,θ max ],θ max For boundary values of the angle, the three directional components of the velocity can be described by θ by the coordinate system change as:
in the formula (I), the compound is shown in the specification,a rotation matrix from an LVLH coordinate system to a geocentric inertia coordinate system;
the magnitude of the velocity is deduced according to the displacement formula of the position velocity and the number of the tracks C Expression (c):
in the formula, e Cmax Is the allowable upper limit of the eccentricity of the fly-over orbit;
by discrete v C And the value of theta in the respective upper and lower bounds, and the guess value is:
in the formula, N 1 And N 2 For the number of discrete points, α and β are both integers, and θ is guess Carrying in formula (11) to obtain a guess initial value of the direction;
s31, if the set flying trace is estimated by a single pulse, the number of orbit deviations caused by the single pulse are:
the magnitude of the velocity increment Δ v of a single pulse is:
in the formula,. DELTA.v a =0.5v C0 Δa/a C0 ,Δv i =v C0 Δi,Δv Ω =v C0 ΔΩsini C0 ,v C0 The average orbit speed of the spacecraft at the initial moment is taken as the average orbit speed;
taking the square of the speed increment as an objective function of the optimal problem, the expression is as follows:
since the modulus values in the three unit directions of velocity are 1, the equality constraint is introduced as:
establishing a Lagrange equation, wherein the expression is as follows:
L=f+λ T g+κ T σ (18)
in the formula, λ is an equality constraint multiplier, κ is an inequality constraint multiplier, and according to the kun-tak condition, the partial derivatives of the four unknowns are solved, so that an 8-dimensional equality equation set is obtained:
in the formula, relate to a C ,e C ,i C ,Ω C ,ω C For v C ,γ x ,γ y ,γ z The partial derivatives of (2) are expressed by the number of the tracks in terms of position and velocity, and are recorded in terms of h C =[h Cx ,h Cy ,h Cz ] T ,e C =[e Cx ,e Cy ,e Cz ] T The expression is:
wherein h is C For the angular momentum of the fly-over orbit, let γ ═ γ x ,γ y ,γ z ] T The partial derivatives can be derived as:
note i x =[1,0,0] T ,i y =[0,1,0] T ,i z =[0,0,1] T Angular momentum vector h C And its modulus value h C About v C The partial derivatives of γ are:
relative velocity vector δ v and its modulus value δ v with respect to v C The partial derivatives of γ are:
eccentricity vector e C About v C The partial derivatives of γ are:
based on the initial value [ v ] of the flying speed given in step S3 C ,γ x ,γ y ,γ z ] 0 And the initial values of the equality constraint and inequality constraint multipliers [ lambda, kappa ] 1 ,κ 2 ,κ 3 ] 0 When the flying speed is 0, a Powell-based mixed numerical value iterator iterates to obtain a final flying speed solution;
s32, obtaining the final flying speed solution, generating a phase difference
Wherein u is Cf Extrapolating the phase of the spacecraft to the moment of flight for the spacecraft,andfor the precession rate deviation of the spacecraft when the spacecraft has movement relative to no movement, the relative average angular velocity is approximated to the first order, and the following can be obtained:
the phase correction is carried out by using the semimajor axis deviation, so that the delta u + delta n C Δ t is 0, and the modified semimajor axis expression is:
wherein N ∈ [ -1,1] represents the number of turns, and the magnitude of the flying speed after correction is as follows:
S33, converting the flying cost estimation into a rendezvous cost estimation, and estimating according to a rendezvous estimation algorithm;
s34, repeating the steps S30-S33, counting the speed increment delta v generated by each iteration, and selecting the minimum value to be recorded as delta v best The corresponding fly-over velocity is solved as [ v C ,γ x ,γ y ,γ z ] best 。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202210737971.9A CN114889849B (en) | 2022-06-23 | 2022-06-23 | Estimation method for multi-constraint fly-through optimal speed of spacecraft |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202210737971.9A CN114889849B (en) | 2022-06-23 | 2022-06-23 | Estimation method for multi-constraint fly-through optimal speed of spacecraft |
Publications (2)
Publication Number | Publication Date |
---|---|
CN114889849A true CN114889849A (en) | 2022-08-12 |
CN114889849B CN114889849B (en) | 2023-10-20 |
Family
ID=82730118
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202210737971.9A Active CN114889849B (en) | 2022-06-23 | 2022-06-23 | Estimation method for multi-constraint fly-through optimal speed of spacecraft |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN114889849B (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115790607A (en) * | 2023-01-31 | 2023-03-14 | 南京航空航天大学 | Short arc historical data-based non-cooperative target maneuvering characteristic detection method |
CN116495196A (en) * | 2023-06-29 | 2023-07-28 | 南京航空航天大学 | Determination method for deep space exploration spacecraft star capturing orbit |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6302354B1 (en) * | 2000-06-07 | 2001-10-16 | The Aerospace Corporation | Space vehicular fly-by guidance method |
CN107992682A (en) * | 2017-12-05 | 2018-05-04 | 北京理工大学 | A kind of optimal multiple-pulse transfer method of interplanetary multi-body system asteroid detection |
CN112231943A (en) * | 2020-12-17 | 2021-01-15 | 中国人民解放军国防科技大学 | Multi-star fly-over sequence searching method and system containing 'one stone and multiple birds' fly-over segments |
CN113343561A (en) * | 2021-05-25 | 2021-09-03 | 中国科学院国家空间科学中心 | Method and system for solving optimal moon fly-by transfer orbit |
CN114019995A (en) * | 2021-11-09 | 2022-02-08 | 北京航空航天大学 | Different-plane multi-target rapid fly-by trajectory planning method with optimal fuel |
-
2022
- 2022-06-23 CN CN202210737971.9A patent/CN114889849B/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6302354B1 (en) * | 2000-06-07 | 2001-10-16 | The Aerospace Corporation | Space vehicular fly-by guidance method |
CN107992682A (en) * | 2017-12-05 | 2018-05-04 | 北京理工大学 | A kind of optimal multiple-pulse transfer method of interplanetary multi-body system asteroid detection |
CN112231943A (en) * | 2020-12-17 | 2021-01-15 | 中国人民解放军国防科技大学 | Multi-star fly-over sequence searching method and system containing 'one stone and multiple birds' fly-over segments |
CN113343561A (en) * | 2021-05-25 | 2021-09-03 | 中国科学院国家空间科学中心 | Method and system for solving optimal moon fly-by transfer orbit |
CN114019995A (en) * | 2021-11-09 | 2022-02-08 | 北京航空航天大学 | Different-plane multi-target rapid fly-by trajectory planning method with optimal fuel |
Non-Patent Citations (2)
Title |
---|
朱彦伟,杨乐平: "航天器在轨服务接近策略研究", 中国空间科学技术, no. 01, pages 14 - 20 * |
潘迅,泮斌峰,唐硕: "求解中途飞越燃料最优转移轨道的同伦方法", 宇航学报, vol. 38, no. 04, pages 393 - 400 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115790607A (en) * | 2023-01-31 | 2023-03-14 | 南京航空航天大学 | Short arc historical data-based non-cooperative target maneuvering characteristic detection method |
CN115790607B (en) * | 2023-01-31 | 2023-05-12 | 南京航空航天大学 | Non-cooperative target maneuvering characteristic detection method based on short arc historical data |
CN116495196A (en) * | 2023-06-29 | 2023-07-28 | 南京航空航天大学 | Determination method for deep space exploration spacecraft star capturing orbit |
CN116495196B (en) * | 2023-06-29 | 2023-09-29 | 南京航空航天大学 | Determination method for deep space exploration spacecraft star capturing orbit |
Also Published As
Publication number | Publication date |
---|---|
CN114889849B (en) | 2023-10-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN109823571B (en) | Multi-stage attitude control method for remote sensing micro-nano satellite | |
CN114889849A (en) | Estimation method for multi-constraint flying-over optimal speed of spacecraft | |
CN109911249B (en) | Interstellar transfer limited thrust orbit-entering iterative guidance method for low thrust-weight ratio aircraft | |
CN109269504B (en) | Attitude maneuver path planning method with terminal constraint | |
CN112572835B (en) | Satellite in-orbit angular momentum management and control method with attitude switching function | |
CN110632935B (en) | Autonomous control method for formation satellite flying around | |
CN110244767B (en) | Formation configuration reconstruction optimization method adopting finite element method | |
CN113602532A (en) | Solid carrier rocket in-orbit correction method | |
CN111605737A (en) | Spacecraft three-phase control multi-level collaborative planning and agile maneuvering method | |
CN111338367A (en) | Method for determining middle track under double-pulse control of same track for freezing eccentricity ratio | |
CN112713922A (en) | Visibility rapid forecasting algorithm of multi-beam communication satellite | |
CN115373423A (en) | Formation capture method for commercial satellite | |
CN113447043A (en) | GNSS-based satellite astronomical navigation system error autonomous calibration method and system | |
McAdams et al. | MESSENGER mission design and navigation | |
CN110955255A (en) | High-precision orbit control attitude maintaining method, system and medium based on CMG | |
CN114063645B (en) | Eccentricity inclination angle vector-based inclination flying-around holding control effect evaluation method | |
CN114684389A (en) | Moon-to-earth transfer window considering reentry constraint and accurate transfer orbit determination method | |
CN114070403B (en) | Feedforward tracking control method and system for inter-satellite laser communication system | |
CN111891402B (en) | Mars detection ground antenna pointing recovery method based on autonomous maneuvering | |
Lincoln et al. | Components of a vision assisted constrained autonomous satellite formation flying control system | |
Somov et al. | A space robot control at approaching and inspecting a geostationary satellite state | |
Han et al. | Engineering Optimization Method of Orbit Transfer Strategy for All-electric Propulsion Satellites | |
CN112455725A (en) | Method for transferring and converting pulse orbit transfer direction to limited thrust orbit | |
Xie et al. | Autonomous guidance, navigation, and control of spacecraft | |
CN113071712B (en) | Rapid calculation method for monthly transition injection-to-orbit strategy |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |