CN113602531B - Method and system for generating combined GEO (generic object oriented) orbit strategy under abnormal separation condition - Google Patents

Abstract

The invention provides a method and a system for generating a combined GEO (generic object oriented) orbit strategy under the condition of abnormal separation, comprising the following steps: determining a combination body separation point track parameter and a platform parameter related to combination body track transfer strategy generation according to the abnormal separation moment state between the combination body and the carrier or the combination body; determining design constraint conditions of a track transfer strategy according to platform parameters; according to the constraint condition, estimating the optimal track change times by taking the minimum speed increment required by track transfer as a principle; establishing a mathematical model describing single track change state change and multiple track change connection according to the estimation result; and generating a track transfer strategy meeting design constraint by using the mathematical model and taking the GEO track as a target through iterative optimization. The method solves the defects of large calculated amount, low calculated speed and the like of the traditional limited thrust complex design method under the abnormal separation condition of the combined spacecraft, and has certain engineering practicability.

Description

Method and system for generating combined GEO (generic object oriented) orbit strategy under abnormal separation condition

Technical Field

The invention relates to the orbit dynamics of an aerospace vehicle, in particular to a method and a system for generating a combined body GEO orbit change strategy under the condition of abnormal separation.

Background

Geostationary orbit spacecraft (GEO) has a relatively "stationary" feature with respect to the earth and is widely used in the fields of communications, navigation, relay, etc. Compared with the traditional single spacecraft, the combined spacecraft has the advantages that each cabin section carries a propulsion system, so that on one hand, the combined spacecraft has better robustness when dealing with abnormal situations of an active section and a plurality of track transfer sections, and on the other hand, the combined spacecraft is required to quickly design a track transfer strategy for the combined spacecraft or each cabin section of the combined spacecraft under the abnormal separation situation of the combined spacecraft.

The transfer orbit strategy which is applied at home and abroad at present has more design schemes, but is mostly a complex integral optimizing method based on limited thrust or a sectional orbit transferring method based on a hybrid propulsion system. Liu Junyao, zhao Jianwei and Zong Yan, etc. in the Chinese patent 'a method for transferring pulse orbits to limited thrust orbits' (patent document: CN 112455725A), firstly, the position of a pulse ignition point is determined, then limited thrust integral optimization is carried out at the position, and the ignition direction is corrected. Lin Baojun, jiang Guowei, fan Yuan and the like in China patent (patent document: CN 111891396A) propose a method and a system for transferring small geostationary satellite orbits, wherein a chemical propulsion system is firstly utilized for lifting the near-position height of a spacecraft, an electric propulsion system is utilized for adjusting the near-position height, the inclination angle and the eccentricity of the spacecraft, and finally the chemical propulsion system is utilized for capturing the spacecraft at fixed points; on one hand, the near-site height, the inclination angle and the eccentricity are adjusted in stages, so that the fuel consumption is high, and the on-orbit service life of the spacecraft is influenced.

In summary, the need for rapid generation of the GEO orbit transfer strategy of the combined spacecraft aiming at the abnormal separation condition is needed, and design optimization of the orbit transfer strategy method is developed.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method and a system for generating a combined body GEO orbit transfer strategy under the condition of abnormal separation.

The invention provides a method for generating a combined body GEO orbit transfer strategy under abnormal separation condition, which comprises the following steps:

step A: determining a combination body separation point track parameter and a platform parameter related to combination body track transfer strategy generation according to the abnormal separation moment state between the combination body and the carrier or the combination body;

and (B) step (B): determining design constraint conditions of a track transfer strategy according to platform parameters;

step C: according to the constraint condition, estimating the optimal track change times by taking the minimum speed increment required by track transfer as a principle;

step D: establishing a mathematical model describing single track change state change and multiple track change connection according to the estimation result;

step E: and generating a track transfer strategy meeting design constraint by using the mathematical model and taking the GEO track as a target through iterative optimization.

Preferably, the step a includes:

step S2.1: the combined body comprises a plurality of cabin sections, each cabin section carries a propulsion system, and the abnormal separation comprises an abnormal emission section which is separated in advance when a carrier fails to send the combined body to a preset track and an abnormal transfer section which is separated in advance when a cabin section in the combined body fails to send the combined body to a quasi-geosynchronous track; firstly, determining the track state at the abnormal separation moment, describing by adopting a GEO track general form, and determining the semi-long axis a ₀ Inclination angle i ₀ Eccentricity e ₀ Geographical longitude lambda ₀ Geographic latitude eta ₀ ；

Step S2.2: defining relevant platform parameters of combined spacecraft, main star or main star and propulsion cabin, including weight m at separation moment ₀ The residual quantity of usable fuel m' ₀ Thrust F of engine ₀ Specific engine stroke Isp ₀ 。

Preferably, in the step B:

three design constraints are introduced in combination with actual engineering: ground measurement and control conditions are used for restraining geographical longitude span of an ignition section, measurement and control duration, characteristics of a thruster, arc section loss and safety protection requirements, and restraining single longest ignition time and available fuel for an orbit transfer object.

Preferably, in the step C, in order to determine the dimension of the track transfer optimization parameter, the optimal track transfer number estimation is performed according to the following steps with the minimum speed increment required for transfer as a rule:

step S4.1: the minimum speed increment Deltav of the spacecraft transferred from the abnormal separation moment state to the GEO target orbit is calculated according to the following formula:

Δv＝v _n -v ₀

wherein ,r₀ The ground center distance at the abnormal separation moment of the transfer track design object is calculated by the track number; a, a ₀ Is a semi-long axis of the track; mu is the gravitational constant; v ₀ Designing an abnormal separation moment speed of an object for a transfer track; v _n Is the target track speed; a, a _n Is a semi-long axis of the target track;

step S4.2: according to a rocket formula, calculating fuel consumption delta m corresponding to the track transfer minimum speed increment:

wherein g=9.80665 m/s ² Is the gravitational acceleration;

step S4.3: the propellant second flow dm is calculated according to the engine specific impulse, and the total track change duration t is calculated by combining the fuel consumption:

step S4.4: combined with single longest ignition time T of thruster _max Calculating to obtain an optimal track change frequency estimation value N:

wherein [ x ] is an eave function, and represents that the smallest integer which is larger than or equal to x is taken.

Preferably, the step D includes:

step S5.1: according to the variable to be optimized for each ignition: semi-long axis a of orbit transfer target _k Offset circle number Q before track change _k K=1, …, N, calculate pre-ignition parameters:

track period T _k ：

Longitude drift rate

wherein ,ω_e ＝7.2921×10 ^-5 rad/s, pi is the circumference ratio.

Ascending intersection geographic longitude lambda _k ：

Step S5.2: according to the target semi-long axis a of each orbit _k K=1, …, N, single firing point and target trajectory parameters were calculated:

calculating the target track speed v by using the vitality formula _k ：

wherein ,r_k The ground center distance of the ignition moment of the transfer track design object is calculated by the track number;

track change speed delta Deltav _k ：

Wherein alpha and beta _k Calculated according to the following formula

β _k ＝π-i _k-1 -α

Back inclination angle i of rail change _k ：

Rail change fuel consumption Δm _k ：

Ignition time t _k ：

Preferably, the step E includes:

step S6.1: converting the GEO orbit transfer strategy solving problem into a multivariable, multi-objective and multi-constraint optimizing problem, wherein an optimizing model is described as follows:

objective function:

wherein ,

representing an orbit objective penalty function;

Representing the deviation between the j-th track parameter track-change final value and the target track; Δorb= (Δa, Δi, Δe, Δλ, Δη) tableShowing the deviation of the track change result from the target track; gamma represents a weight coefficient;

constraint conditions:

step S6.2: selecting a multi-variable, multi-objective and multi-constraint optimization algorithm for iterative optimization aiming at the optimization model;

step S6.3: outputting the optimizing result, and determining the GEO orbit transfer strategy of the combined spacecraft under the abnormal separation condition.

According to the invention, the combined GEO orbital transfer strategy generation system under the abnormal separation condition comprises the following components:

module a: determining a combination body separation point track parameter and a platform parameter related to combination body track transfer strategy generation according to the abnormal separation moment state between the combination body and the carrier or the combination body;

module B: determining design constraint conditions of a track transfer strategy according to platform parameters;

module C: according to the constraint condition, estimating the optimal track change times by taking the minimum speed increment required by track transfer as a principle;

module D: establishing a mathematical model describing single track change state change and multiple track change connection according to the estimation result;

module E: and generating a track transfer strategy meeting design constraint by using the mathematical model and taking the GEO track as a target through iterative optimization.

Preferably, the module a comprises:

module S2.1: the combined body comprises a plurality of cabin sections, each cabin section carries a propulsion system, and the abnormal separation comprises an abnormal emission section which is separated in advance when a carrier fails to send the combined body to a preset track and an abnormal transfer section which is separated in advance when a cabin section in the combined body fails to send the combined body to a quasi-geosynchronous track; firstly, determining the track state at the abnormal separation moment, describing by adopting a GEO track general form, and determining the semi-long axis a ₀ Inclination angle i ₀ Eccentricity e ₀ Geographical longitude lambda ₀ Geographic latitude eta ₀ ；

Module S2.2: defining relevant platform parameters of combined spacecraft, main star or main star and propulsion cabin, including weight m at separation moment ₀ The residual quantity of usable fuel m' ₀ Thrust F of engine ₀ Specific engine stroke Isp ₀ 。

In the module B:

three design constraints are introduced in combination with actual engineering: ground measurement and control conditions are used for restraining geographical longitude span of an ignition section, measurement and control duration, characteristics of a thruster, arc section loss and safety protection requirements, and restraining single longest ignition time and available fuel for an orbit transfer object.

Preferably, in the module C, in order to determine the dimension of the track transfer optimization parameter, the optimal track transfer number estimation is performed according to the following module based on the minimum speed increment required for transfer:

module S4.1: the minimum speed increment Deltav of the spacecraft transferred from the abnormal separation moment state to the GEO target orbit is calculated according to the following formula:

Δv＝v _n -v ₀

wherein ,r₀ The ground center distance at the abnormal separation moment of the transfer track design object is calculated by the track number; a, a ₀ Is a semi-long axis of the track; mu is the gravitational constant; v ₀ Designing an abnormal separation moment speed of an object for a transfer track; v _n Is the target track speed; a, a _n Is a semi-long axis of the target track;

module S4.2: according to a rocket formula, calculating fuel consumption delta m corresponding to the track transfer minimum speed increment:

wherein g=9.80665 m/s ² Is the gravitational acceleration;

module S4.3: the propellant second flow dm is calculated according to the engine specific impulse, and the total track change duration t is calculated by combining the fuel consumption:

module S4.4: combined with single longest ignition time T of thruster _max Calculating to obtain an optimal track change frequency estimation value N:

wherein [ x ] is an eave function, and represents that the smallest integer which is larger than or equal to x is taken.

Preferably, the module D comprises:

module S5.1: according to the variable to be optimized for each ignition: semi-long axis a of orbit transfer target _k Offset circle number Q before track change _k K=1, …, N, calculate pre-ignition parameters:

track period T _k ：

Longitude drift rate

wherein ,ω_e ＝7.2921×10 ^-5 rad/s, pi is the circumference ratio.

Intersection point of ascendingGeographical longitude lambda _k ：

Module S5.2: according to the target semi-long axis a of each orbit _k K=1, …, N, single firing point and target trajectory parameters were calculated:

calculating the target track speed v by using the vitality formula _k ：

wherein ,r_k The ground center distance of the ignition moment of the transfer track design object is calculated by the track number;

track change speed delta Deltav _k ：

Wherein alpha and beta _k Calculated according to the following formula

β _k ＝π-i _k-1 -α

Back inclination angle i of rail change _k ：

Rail change fuel consumption Δm _k ：

Ignition time t _k ：

Preferably, the module E comprises:

module S6.1: converting the GEO orbit transfer strategy solving problem into a multivariable, multi-objective and multi-constraint optimizing problem, wherein an optimizing model is described as follows:

objective function:

wherein ,

representing an orbit objective penalty function;

Representing the deviation between the j-th track parameter track-change final value and the target track; Δorb= (Δa, Δi, Δe, Δλ, Δη) representing the track change result deviation from the target track; gamma represents a weight coefficient;

constraint conditions:

module S6.2: selecting a multi-variable, multi-objective and multi-constraint optimization algorithm for iterative optimization aiming at the optimization model;

module S6.3: outputting the optimizing result, and determining the GEO orbit transfer strategy of the combined spacecraft under the abnormal separation condition.

Compared with the prior art, the invention has the following beneficial effects:

the method solves the defects of large calculated amount, low calculated speed and the like of the traditional limited thrust complex design method under the abnormal separation condition of the combined spacecraft, and has certain engineering practicability.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the detailed description of non-limiting embodiments, given with reference to the accompanying drawings in which:

FIG. 1 is a schematic block diagram of a method for quickly generating a combined GEO orbit transfer strategy under the abnormal separation condition;

FIG. 2 is a schematic view of the configuration of the combined spacecraft (two cabin sections);

FIG. 3 is a schematic view of an assembled spacecraft and launch anomaly separation (tilt angle out-of-tolerance) orbit;

FIG. 4 is a simulation diagram of a GEO orbit transfer strategy for an assembled spacecraft based on abnormal separation conditions.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any way. It should be noted that variations and modifications could be made by those skilled in the art without departing from the inventive concept. These are all within the scope of the present invention.

As shown in figure 1, the invention provides a method for quickly generating a combined GEO orbit transfer strategy under the condition of abnormal separation. The method specifically comprises the following steps:

step A: and determining the track parameters of the separation points of the combination and the platform parameters related to the generation of the track transfer strategy of the combination according to the abnormal separation moment state between the combination and the carrier or the combination.

And (B) step (B): and determining the design constraint conditions of the track transfer strategy according to factors such as ground measurement and control requirements, single ignition capability and the like.

Step C: and estimating the optimal track change times by taking the minimum speed increment required by track transfer as a principle.

Step D: as shown in fig. 4, a mathematical model describing the single change of track state and the relationship between multiple tracks is established.

Step E: and (3) taking the GEO track as a target, and rapidly generating a track transfer strategy meeting design constraint through iterative optimization.

The step A comprises the following steps:

step S2.1: as shown in fig. 2, the composite spacecraft typically comprises a plurality of tanks, and each tank carries a propulsion system. As shown in fig. 3, the anomaly separation includes anomaly of a launching segment, which is a premature separation, of the combined spacecraft, which is a failure of the carrier to send the combined spacecraft to a predetermined orbit, and anomaly of a transfer segment, which is a premature separation, of the combined spacecraft, which is a failure of a certain cabin of the combined spacecraft to a quasi-geosynchronous orbit, and in order to design a spacecraft orbit transfer strategy, firstly, an orbit state at the moment of anomaly separation needs to be clarified. Without loss of generality, the description is given in general form of GEO orbits, i.e., semi-major axis a ₀ Inclination angle i ₀ Eccentricity e ₀ Geographical longitude lambda ₀ Geographic latitude eta ₀ ；

Step S2.2: in addition, there is also a need for explicit transfer strategy to design relevant platform parameters of the object (combined spacecraft, main star or main star and propulsion pod), typically including the separation moment weight m ₀ The residual quantity of usable fuel m' ₀ Thrust F of engine ₀ Specific engine stroke Isp ₀ ；

In the step B, 3 aspects of design constraint are induced by combining the actual engineering requirements: ground measurement and control conditions are used for restraining the geographical longitude span of the ignition section, the measurement and control duration, the characteristics of a thruster, the arc loss and the safety protection requirements, and restraining the single longest ignition time and the available fuel of a rail-changing object;

in step C, in order to determine the dimension of the track transfer optimization parameter, the optimal track transfer frequency estimation is performed according to the following steps with the minimum speed increment required by transfer as a principle:

step S4.1: the minimum speed increment Deltav of the spacecraft transferred from the abnormal separation moment state to the GEO target orbit is calculated according to the following formula:

Δv＝v _n -v ₀

wherein ,r₀ The earth center distance at the moment of abnormal separation of the design object of the transfer track can be calculated by the track numberObtaining; v ₀ Designing an abnormal separation moment speed of an object for a transfer track; v _n Is the target track speed; a, a _n For the semi-long axis of the target track, the GEO track is usually 42164km;

step S4.2: according to a rocket formula, calculating fuel consumption delta m corresponding to the track transfer minimum speed increment:

wherein g=9.80665 m/s ² Is the gravitational acceleration;

step S4.3: the propellant second flow dm is calculated according to the engine specific impulse, and the total track change duration t is calculated by combining the fuel consumption:

step S4.4: combined with single longest ignition time T of thruster _max Calculating to obtain an optimal track change frequency estimation value N:

wherein [ x ] is an eave function, and represents that the smallest integer which is larger than or equal to x is taken.

The step D comprises the following steps:

step S5.1: according to the variable to be optimized for each ignition, i.e. the semi-long axis a of the orbit transfer target _k Offset circle number Q before track change _k K=1, …, N calculates the pre-ignition parameter:

track period T _k ：

Longitude drift rate

wherein ,ω_e ＝7.2921×10 ^-5 rad/s

Ascending intersection geographic longitude lambda _k ：

Step S5.2: according to the target semi-long axis a of each orbit _k K=1, …, N, single firing point and target trajectory parameters were calculated:

calculating the target track speed v by using the vitality formula _k ：

wherein ,r_k The ground center distance of the ignition moment of the transfer track design object can be calculated by the track number;

track change speed delta Deltav _k ：

Wherein alpha and beta _k Calculated according to the following formula

β _k ＝π-i _k-1 -α

Back inclination angle i of rail change _k ：

Rail change fuel consumption Δm _k ：

Ignition time t _k ：

The step E comprises the following steps:

step S6.1: converting the GEO orbit transfer strategy solving problem into a multivariable, multi-objective and multi-constraint optimizing problem, wherein an optimizing model is described as follows:

objective function:

wherein ,

representing an orbit objective penalty function;

Representing the deviation between the j-th track parameter track-change final value and the target track; Δorb= (Δa, Δi, Δe, Δλ, Δη) representing the track change result deviation from the target track; gamma represents a weight coefficient, and a larger positive integer is taken for carrying out large weight penalty on parameters which do not meet the precision index;

constraint conditions:

step S6.2: selecting the existing multivariable, multi-objective and multi-constraint optimization algorithm for the optimization model to perform iterative optimization;

step S6.3: outputting the optimizing result, and determining the GEO orbit transfer strategy of the combined spacecraft under the abnormal separation condition.

In this embodiment, assuming that an abnormality occurs at the separation time of the carrier and the combined spacecraft, the orbit inclination angle is deviated due to the carrier failure leading to the separation time, and the separation orbit parameter is determined according to step a:

Orb ₀ ＝(a ₀ ,i ₀ ,e ₀ ,λ ₀ ,η ₀ )＝(24473.64km,30°,0.731215,-9.21°,30°)

the platform parameters for determining the combination and track transfer are as follows: weight at separation time m ₀ =3863 kg, available fuel remaining m' ₀ 1820kg, engine thrust F ₀ =350n, engine specific impulse Isp ₀ ＝315s；

Determining track transfer strategy design constraints according to step B: shortest measurement and control time t _fire More than or equal to 30min, the ground measurement and control geographical longitude range [30 DEG E,170 DEG E]Maximum time t for single ignition of engine _engine 4050s or less and the most available fuel for track transfer

According to step C, the GEO target orbit parameter Orb is combined _n = (42164 km,30 °,0,60 °,0 °) estimates the number of track changes:

and finally, according to the established optimization model in the step E, carrying out single track change state change and multiple track change parameter updating in combination with the step D, and generating a track transfer strategy meeting design constraints as shown in the table 1 through iterative optimization.

TABLE 1 iterative optimization solution for track transfer strategy

The invention also provides a system for generating the combined GEO orbit transfer strategy under the abnormal separation condition, which comprises the following steps:

module a: and determining the track parameters of the separation points of the combination and the platform parameters related to the generation of the track transfer strategy of the combination according to the abnormal separation moment state between the combination and the carrier or the combination.

Module B: and determining design constraint conditions of the track transfer strategy according to the platform parameters.

Module C: and estimating the optimal track change times according to the constraint condition by taking the minimum speed increment required by track transfer as a principle.

Module D: and establishing a mathematical model describing single track change state change and multiple track change connection according to the estimation result.

Module E: and generating a track transfer strategy meeting design constraint by using the mathematical model and taking the GEO track as a target through iterative optimization.

Those skilled in the art will appreciate that the invention provides a system and its individual devices, modules, units, etc. that can be implemented entirely by logic programming of method steps, in addition to being implemented as pure computer readable program code, in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. Therefore, the system and various devices, modules and units thereof provided by the invention can be regarded as a hardware component, and the devices, modules and units for realizing various functions included in the system can also be regarded as structures in the hardware component; means, modules, and units for implementing the various functions may also be considered as either software modules for implementing the methods or structures within hardware components.

The foregoing describes specific embodiments of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that various changes or modifications may be made by those skilled in the art within the scope of the appended claims without affecting the spirit of the invention. The embodiments of the present application and features in the embodiments may be combined with each other arbitrarily without conflict.

Claims (2)

1. The method for generating the combined GEO orbit transfer strategy under the abnormal separation condition is characterized by comprising the following steps of:

step A: determining a combination body separation point track parameter and a platform parameter related to combination body track transfer strategy generation according to the abnormal separation moment state between the combination body and the carrier or the combination body;

and (B) step (B): determining design constraint conditions of a track transfer strategy according to platform parameters;

the ground measurement and control conditions are used for restraining the geographical longitude span of the ignition section, the measurement and control duration, the characteristics of the thruster, the arc section loss and the safety protection requirement, and restraining the longest ignition time of a single time and the available fuel of a rail-changing object;

step C: according to the constraint condition, estimating the optimal track change times by taking the minimum speed increment required by track transfer as a principle;

step D: establishing a mathematical model describing single track change state change and multiple track change connection according to the estimation result;

step E: generating a track transfer strategy meeting design constraint by using the mathematical model and taking a GEO track as a target through iterative optimization;

the step A comprises the following steps:

step S2.1: the combined body comprises a plurality of cabin sections, each cabin section carries a propulsion system, and the abnormal separation comprises an abnormal emission section which is separated in advance when a carrier fails to send the combined body to a preset track and an abnormal transfer section which is separated in advance when a cabin section in the combined body fails to send the combined body to a quasi-geosynchronous track; firstly, determining the track state at the abnormal separation moment, describing by adopting a GEO track general form, and determining the semi-long axis a ₀ Tilting and leaningAngle i ₀ Eccentricity e ₀ Geographical longitude lambda ₀ Geographic latitude eta ₀ ；

Step S2.2: defining relevant platform parameters of combined spacecraft, main star or main star and propulsion cabin, including weight m at separation moment ₀ The residual quantity of usable fuel m' ₀ Thrust F of engine ₀ Specific engine stroke Isp ₀ ；

In the step C, in order to determine the dimension of the track transfer optimization parameter, the optimal track transfer frequency estimation is performed according to the following steps with the minimum speed increment required by transfer as a principle:

step S4.1: the minimum speed increment Deltav of the spacecraft transferred from the abnormal separation moment state to the GEO target orbit is calculated according to the following formula:

Δv＝v _n -v ₀

wherein ,r₀ The ground center distance at the abnormal separation moment of the transfer track design object is calculated by the track number; a, a ₀ Is a semi-long axis of the track; mu is the gravitational constant; v ₀ Designing an abnormal separation moment speed of an object for a transfer track; v _n Is the target track speed; a, a _n Is a semi-long axis of the target track;

step S4.2: according to a rocket formula, calculating fuel consumption delta m corresponding to the track transfer minimum speed increment:

wherein g=9.80665 m/s ² Is the gravitational acceleration;

step S4.3: the propellant second flow dm is calculated according to the engine specific impulse, and the total track change duration t is calculated by combining the fuel consumption:

step S4.4: combined with single longest ignition time T of thruster _max Calculating to obtain an optimal track change frequency estimation value N:

wherein [ x ] is an eave function, and represents that the minimum integer which is more than or equal to x is taken;

the step D comprises the following steps:

step S5.1: according to the variable to be optimized for each ignition: semi-long axis a of orbit transfer target _k Offset circle number Q before track change _k K=1, …, N, calculate pre-ignition parameters:

track period T _k ：

Longitude drift rate

wherein ,ω_e ＝7.2921×10 ^-5 rad/s, pi is the circumference ratio;

ascending intersection geographic longitude lambda _k ：

Step S5.2: according to the target semi-long axis a of each orbit _k K=1, …, N, single firing point and target trajectory parameters were calculated:

calculating the target track speed v by using the vitality formula _k ：

wherein ,r_k The ground center distance of the ignition moment of the transfer track design object is calculated by the track number;

track change speed delta Deltav _k ：

Wherein alpha and beta _k Calculated according to the following formula

β _k ＝π-i _k-1 -α

Back inclination angle i of rail change _k ：

Rail change fuel consumption Δm _k ：

Ignition time t _k ：

The step E comprises the following steps:

step S6.1: converting the GEO orbit transfer strategy solving problem into a multivariable, multi-objective and multi-constraint optimizing problem, wherein an optimizing model is described as follows:

objective function:

wherein ,

representing an orbit objective penalty function;

Representing the deviation between the j-th track parameter track-change final value and the target track; Δorb= (Δa, Δi, Δe, Δλ, Δη) representing the track change result deviation from the target track; gamma represents a weight coefficient;

constraint conditions:

step S6.2: selecting a multi-variable, multi-objective and multi-constraint optimization algorithm for iterative optimization aiming at the optimization model;

step S6.3: outputting the optimizing result, and determining the GEO orbit transfer strategy of the combined spacecraft under the abnormal separation condition.

2. An assembly GEO-tracking strategy generation system under abnormal separation conditions, comprising:

module a: determining a combination body separation point track parameter and a platform parameter related to combination body track transfer strategy generation according to the abnormal separation moment state between the combination body and the carrier or the combination body;

module B: determining design constraint conditions of a track transfer strategy according to platform parameters;

the module B is used for limiting the geographic longitude span of the ignition section, the measurement and control duration, the characteristics of the thruster, the arc section loss and the safety protection requirement of the ground measurement and control condition to the single longest ignition time and the available fuel of the track-changing object;

module C: according to the constraint condition, estimating the optimal track change times by taking the minimum speed increment required by track transfer as a principle;

module D: establishing a mathematical model describing single track change state change and multiple track change connection according to the estimation result;

module E: generating a track transfer strategy meeting design constraint by using the mathematical model and taking a GEO track as a target through iterative optimization;

the module a includes:

module S2.1: the combined body comprises a plurality of cabin sections, each cabin section carries a propulsion system, and the abnormal separation comprises an abnormal emission section which is separated in advance when a carrier fails to send the combined body to a preset track and an abnormal transfer section which is separated in advance when a cabin section in the combined body fails to send the combined body to a quasi-geosynchronous track; firstly, determining the track state at the abnormal separation moment, describing by adopting a GEO track general form, and determining the semi-long axis a ₀ Inclination angle i ₀ Eccentricity e ₀ Geographical longitude lambda ₀ Geographic latitude eta ₀ ；

Module S2.2: defining relevant platform parameters of combined spacecraft, main star or main star and propulsion cabin, including weight m at separation moment ₀ The residual quantity of usable fuel m' ₀ Thrust F of engine ₀ Specific engine stroke Isp ₀ ；

In the module C, in order to determine the dimension of the track transfer optimization parameter, the optimal track transfer frequency estimation is performed according to the following module with the minimum speed increment required by transfer as a principle:

module S4.1: the minimum speed increment Deltav of the spacecraft transferred from the abnormal separation moment state to the GEO target orbit is calculated according to the following formula:

Δv＝v _n -v ₀

wherein ,r₀ The ground center distance at the abnormal separation moment of the transfer track design object is calculated by the track number; a, a ₀ Is a semi-long axis of the track; mu is the gravitational constant; v ₀ Designing an abnormal separation moment speed of an object for a transfer track; v _n Is the target track speed; a, a _n Is a semi-long axis of the target track;

module S4.2: according to a rocket formula, calculating fuel consumption delta m corresponding to the track transfer minimum speed increment:

wherein g=9.80665 m/s ² Is the gravitational acceleration;

module S4.3: the propellant second flow dm is calculated according to the engine specific impulse, and the total track change duration t is calculated by combining the fuel consumption:

module S4.4: combined with single longest ignition time T of thruster _max Calculating to obtain an optimal track change frequency estimation value N:

wherein [ x ] is an eave function, and represents that the minimum integer which is more than or equal to x is taken;

the module D includes:

module S5.1: according to the variable to be optimized for each ignition: semi-long axis a of orbit transfer target _k Offset circle number Q before track change _k K=1, …, N, calculate pre-ignition parameters:

track period T _k ：

Longitude drift rate

wherein ,ω_e ＝7.2921×10 ^-5 rad/s, pi is the circumference ratio;

ascending intersection geographic longitude lambda _k ：

Module S5.2: according to the target semi-long axis a of each orbit _k K=1, …, N, single firing point and target trajectory parameters were calculated:

calculating the target track speed v by using the vitality formula _k ：

wherein ,r_k The ground center distance of the ignition moment of the transfer track design object is calculated by the track number;

track change speed delta Deltav _k ：

Wherein alpha and beta _k Calculated according to the following formula

β _k ＝π-i _k-1 -α

Back inclination angle i of rail change _k ：

Rail change fuel consumption Δm _k ：

Ignition time t _k ：

The module E comprises:

module S6.1: converting the GEO orbit transfer strategy solving problem into a multivariable, multi-objective and multi-constraint optimizing problem, wherein an optimizing model is described as follows:

objective function:

wherein ,

representing an orbit objective penalty function;

Representing the deviation between the j-th track parameter track-change final value and the target track; Δorb= (Δa, Δi, Δe, Δλ, Δη) representing the track change result deviation from the target track; gamma represents a weight coefficient;

constraint conditions:

module S6.2: selecting a multi-variable, multi-objective and multi-constraint optimization algorithm for iterative optimization aiming at the optimization model;

module S6.3: outputting the optimizing result, and determining the GEO orbit transfer strategy of the combined spacecraft under the abnormal separation condition.

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