CN110321643B

CN110321643B - Rapid search method and device for interplanetary detector transmitting opportunity

Info

Publication number: CN110321643B
Application number: CN201910613940.0A
Authority: CN
Inventors: 端军红
Original assignee: Air Force Engineering University of PLA
Current assignee: Air Force Engineering University of PLA
Priority date: 2019-07-08
Filing date: 2019-07-08
Publication date: 2022-10-14
Anticipated expiration: 2039-07-08
Also published as: CN110321643A

Abstract

The invention provides a method and a device for quickly searching a transmission opportunity of a interplanetary detector, wherein the method for quickly searching the transmission opportunity specifically comprises the following steps: acquiring target planet orbit parameters and constraint conditions of an interplanetary exploration task; determining a time window on a transmission time dimension by utilizing a multi-boundary point search method and combining a transmission opportunity search algorithm at a fixed transmission moment according to a task constraint condition; and traversing the time windows on the emission time dimension by using an emission opportunity search algorithm with fixed emission time, and determining the time window on the transfer flight time dimension corresponding to each emission time in each time window so as to obtain all emission opportunities. Compared with the commonly adopted Pock-Chop graph method, the search method provided by the invention has the advantages that the search result is more accurate, and the search time can be shortened by about two orders of magnitude. Therefore, the method is suitable for quick, high-precision and large-scale transmitter opportunity search and evaluation of interplanetary exploration tasks.

Description

Rapid search method and device for interplanetary detector transmitting opportunity

Technical Field

The invention relates to the technical field of spaceflight, in particular to a method and a device for quickly searching for a launching opportunity of an interplanetary detector. The research provided by the invention is subsidized by the national science fund project (11502300).

Background

Interplanetary exploration has become a new direction in the world aerospace development in the 21 st century. Mission planning and design for interplanetary exploration is subject to a number of constraints, such as launch time, transfer flight time, launch energy, required velocity increments after launch, and so forth. These constraints are not only directly related to the design, development cost and complexity of the detector, but also limit the level of carrying the rocket. How to select a suitable feasible or optimal transmission opportunity according to these constraints is a key issue that needs to be considered first for interplanetary exploration.

Currently, the concept of a transmission window is commonly used to represent a transmission opportunity. By launch window is meant the range of time allowed for launching the spacecraft, also known as the launch opportunity. The launch window of the spacecraft is determined according to the space mission and the external limiting conditions and changes along with the change of the factors. For interplanetary detection, after the emission window of the detector is determined, a proper emission time and a corresponding transfer orbit need to be selected according to the emission window. The solution process of the interplanetary sonde transmission window is essentially also the search process of the transmission opportunity. The quality of the transmitter opportunity search algorithm is directly related to the efficiency and flexibility of interplanetary exploration task planning and design.

Currently, the commonly adopted method for searching the transmitting opportunity is a Pork-Chop graph method, which is also called an energy contour graph method. The search method solves the problem of two-point boundary value Lambert of a given emission time period and an arrival time period, and draws a Pork-Chop graph reflecting energy change so as to obtain approximate better emission opportunity. The Pork-Chop graph method is simple and intuitive in principle, and can provide the distribution situation of the emission opportunities meeting the time node constraint and the energy constraint in the whole situation, so that task designers can plan and design tasks more flexibly from the whole situation. However, this method is an exhaustive search method, and some practical constraints cannot be directly added to the search process, so that the search efficiency is low, the calculation amount is huge, and the calculation accuracy cannot be precisely controlled by this method. In addition, some scholars employ optimization algorithms (e.g., genetic algorithms, etc.) to determine optimal solutions for a given transmission time period and arrival time period. The optimization methods improve the efficiency of the transmission opportunity search to a certain extent, but the algorithm has the problems of easy aging, reduced stability and convergence, sensitivity to initial values and the like, and the optimal solution obtained by the optimization method cannot be executed in real time due to some practical engineering requirements (such as other transmission tasks for avoiding time conflicts, important festivals and the like) and some emergency situations (such as system faults and the like), so that only one feasible solution can be selected according to the distribution condition of the transmission opportunities in the whole world. However, the optimization algorithm cannot give a distribution of feasible solutions in the global, so that the design process lacks flexibility. Therefore, the optimization algorithm is difficult to completely meet the practical requirements of interplanetary exploration mission planning and design.

Therefore, the existing transmitter search method brings much inconvenience to planning and design of interplanetary detection tasks. Therefore, the students are still searching for new searching methods of the transmission opportunity to solve the problems of the existing searching methods.

Disclosure of Invention

The invention aims to provide a method and a device for quickly searching a transmitter opportunity of a interplanetary detector, so as to improve the efficiency of transmitter opportunity searching.

In a first aspect, an embodiment of the present invention provides a method for quickly searching for an opportunity to transmit a satellite probe, where the method includes:

acquiring target planet orbit parameters and constraint conditions of an interplanetary exploration task;

determining a time window on a transmission time dimension by utilizing a multi-boundary point search method and combining a transmission opportunity search algorithm at a fixed transmission moment according to the constraint condition of the detection task;

traversing the time windows on the emission time dimension by using the emission opportunity search algorithm of the fixed emission time, and determining the time window on the transfer flight time dimension corresponding to each emission time in each time window, thereby obtaining all emission opportunities.

In a second aspect, an embodiment of the present invention provides a fast search apparatus for interplanetary probe transmission opportunities, where the apparatus includes:

the acquisition unit is used for acquiring target planet orbit elements and constraint conditions of the interplanetary exploration tasks;

a transmitter opportunity search unit with fixed transmission time, which is used for determining a time window on a transfer flight time dimension corresponding to the given transmission time according to the constraint condition of the detection task;

a time window searching unit of the emission time dimension, which is used for determining the time window of the emission time dimension according to the target planet orbit element and the constraint condition of the detection task;

and the traversing unit is used for traversing the time windows in the emission time dimension, and determining the time window in the transfer flight time dimension corresponding to each emission moment in each time window so as to obtain all emission opportunities.

Compared with the currently and generally adopted Pock-Chop graph method, the method for searching the transmission opportunity has the advantages that the searching result is more accurate, and the searching time can be shortened by about two orders of magnitude. Therefore, the method is suitable for quick, high-precision and large-scale transmitter opportunity search and evaluation of interplanetary exploration tasks.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings used in the detailed description or the prior art description will be briefly described below. It is obvious that the drawings in the following description are some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a flowchart of a fast search method for an interplanetary finder transmit opportunity according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a two-dimensional emission window provided in an embodiment of the present invention;

FIG. 3 is a detailed flowchart of a two-dimensional emission window method according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a detector state at the time of transmission according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of potential reachable regions according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a distribution of potential reachable regions according to an embodiment of the present invention;

FIG. 7 is a schematic diagram illustrating a relationship between a target location point and a potential reachable location according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of the relationship among the encounter set, the rendezvous set, and the emission set provided by the embodiment of the invention;

FIG. 9 is a diagram illustrating a situation where a subset of the encounter set is missed according to an embodiment of the present invention;

fig. 10 is a schematic diagram illustrating the location relationship among a potential reachable area, an encounter area, a rendezvous area and a transmitting area according to an embodiment of the present invention;

FIG. 11 is a line contour diagram of emitted energy provided by an embodiment of the present invention;

FIG. 12 is a brake speed pulse contour plot provided by an embodiment of the present invention;

FIG. 13 is a plot of relative distance contours at a time of a meeting as provided by an embodiment of the present invention;

FIG. 14 shows the calculation results of the Pock-Chop graph method according to the embodiment of the present invention;

fig. 15 is a search result of a two-dimensional transmission window method according to an embodiment of the present invention;

FIG. 16 is a partially enlarged view of a search result obtained by the two-dimensional emission window method according to an embodiment of the present invention;

fig. 17 is a schematic diagram of a fast search apparatus for interplanetary finder transmission opportunities according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

The search of the launching opportunity is a key problem in planning and designing the interplanetary detection task, which not only relates to the launching opportunity of the interplanetary detector, but also puts forward the performance index requirements for the design of the detector and the corresponding carrier rocket. The invention provides a quick search method for interplanetary detector transmitting opportunities, namely a two-dimensional transmitting window method. Firstly, for any fixed transmission time, a method for searching the transmission opportunity in the transfer flight time dimension is provided, and the method can obtain all the transmission opportunities corresponding to the transmission time; on the basis, a two-dimensional emission window method is provided, and the method searches emission opportunities in two dimensions of emission time and transfer flight time in sequence and can quickly obtain all the emission opportunities meeting all the constraint conditions; finally, taking the search of the launching opportunity of the near-earth asteroid 4660Nereus rendezvous detection task as an example, the two-dimensional launching window method and the currently and generally adopted Pock-Chop graph method are compared and simulated, and the rapidity and the accuracy of the method are verified. Compared with a Pock-Chop graph method, the two-dimensional emission window method can shorten the search time of the emission opportunity by about two orders of magnitude, so that the method is not only suitable for determining the emission window of a specific interplanetary detection task, but also can be used for searching and evaluating the emission opportunity of a target planet in a fast, high-precision and large-scale manner.

For the understanding of the present embodiment, the following detailed description will be given of the embodiment of the present invention.

The first embodiment is as follows:

fig. 1 is a flowchart of a fast search method for interplanetary probe transmission opportunities according to an embodiment of the present invention.

Referring to fig. 1, the method includes the steps of:

s1, acquiring target planet orbit parameters and constraint conditions of an interplanetary exploration task;

s2, determining a time window [ T ] on a transmission time dimension by utilizing a multi-boundary point search method and combining a transmission opportunity search algorithm of a fixed transmission moment according to the constraint conditions of the detection task _si ,T _ei ]，i＝1,2,…；

In this embodiment, a multi-boundary point search method is used to determine the transmission time period [ T [ ] _start ,T _end ]All sub-intervals T containing transmission opportunities _si ,T _ei ]I =1,2, …, where each subinterval is referred to as a time window in the transmit time dimension. For example, in fig. 2, in the transmit time dimension, there are two time windows: [ T ] _s1 ,T _e1 ]And [ T _s2 ,T _e2 ]. In a multi-boundary-point search method, for each selected emission instantT _launch It is necessary to determine whether there is a transmission opportunity at the transmission time. The transmission time T is determined by using a transmission opportunity search method with fixed transmission time _launch And if the corresponding transmitting set is an empty set, no transmitting opportunity exists at the transmitting moment, otherwise, a transmitting opportunity exists at the transmitting moment.

Step S3, using a transmitting opportunity search algorithm with fixed transmitting time to carry out time window [ T ] on transmitting time dimension _si ,T _ei ]And (i =1,2, …) performing traversal, and determining a time window on a transfer flight time dimension corresponding to each transmission moment in each time window, so as to obtain all transmission opportunities.

In this embodiment, the transmission opportunity search method using a fixed transmission time is used for the time interval T _si ,T _ei ]And (i =1,2, …) respectively performing traversal search, and determining a transmission set corresponding to each transmission moment with the transmission opportunity, namely, shifting a time window on a flight time dimension, so as to obtain all the transmission opportunities. It should be noted that the number of time windows in the transition flight time dimension corresponding to each transmission time instant having a transmission opportunity is different. For example, in FIG. 2, the transmission time T ₁ And T ₂ The number of time windows in the corresponding transfer time-of-flight dimension is 1 and 3, respectively.

The method for searching the transmission opportunity iteratively searches the time windows in two dimensions of the transmission time and the transfer flight time in sequence, wherein the time windows in the two dimensions are at the transmission time T _launch -transfer time of flight t _f A number of two-dimensional emission windows are determined on the plane (as shown in fig. 2), and these two-dimensional emission windows give all the emission opportunities of the interplanetary exploration tasks, so this search method is called two-dimensional emission window method. The searching method can greatly reduce the calculation amount of searching and improve the searching efficiency. The detailed algorithm flow of the whole two-dimensional emission window method is shown in fig. 3.

It should be noted that, the transmission time interval [ T ] is searched by using the multi-boundary point search method _start ,T _end ]When the subinterval containing the transmitter opportunity is selected to be constantSmall search step τ _launch And τ is _launch Need to be suitably large even though it may miss individual widths that are small (less than τ) _launch ) When the sub-interval is located just inside two adjacent search instants. This is because in practice, considering various uncertainty factors during transmission, it is desirable to select a wider transmission time window to ensure that the specific transmission time of the detector can be selected more flexibly, so that the subintervals with too small widths are not of great practical significance.

The two-dimensional emission window method for solving the intersection type detection task emission opportunity is also suitable for the fly-by type detection task. The fly-by type detection task is generally only constrained by emission energy and measurement and control and communication distance in the fly-by process and is not constrained by the relative speed in the fly-by process. Therefore, when searching for a transmission opportunity by using the two-dimensional transmission window method, only the rendezvous set subset at any transmission time needs to be equal to the encounter set subset, namely TF _II ＝TF _I And (4) finishing.

Further, in step S1, the constraints of the probing task include a time node constraint, an energy constraint, and a measurement and control and communication distance constraint, where the time node constraint includes an allowed transmission time period T _start ,T _end ]And a transition flight time period [ T _fmin ,T _fmax ]The energy constraints include a transmit energy constraint and a brake speed pulse size constraint.

Specifically, in the emission energy constraint, the size of the emission velocity pulse from the earth is required

Wherein, C _3max The maximum transmitting energy which can be provided by the last stage of the carrier rocket of the transmitting detector limits the propelling capacity of the last stage of the rocket;

in the braking speed pulse size restriction, the relative speed of the detector and the target planet in intersection is required to be | | Δ v _R ||≤ΔV _D Wherein Δ V _D Maximum speed increment that can be provided for limited interplanetary probe rendezvous brakingThe beam reflects the requirements for the mobility of the probe, which is closely related to the cost and complexity of the probe development.

In the constraint conditions of measurement and control and communication distance, the flight key time point is required to be communicated as far as possible without shielding, and the ground can be measured and controlled. From the analysis of measurement and control, interplanetary detection is mainly limited by measurement and control and communication distance, so that the relative distance between the detector and the earth does not exceed R when meeting _max 。

For the fly-by type detection task, the constraint condition required to be met does not generally contain the relative speed magnitude constraint during intersection, and other constraint conditions are required to be met.

Further, step S2 includes the steps of:

step S21, selecting each discrete transmitting moment by a larger searching step length in the transmitting time period;

s22, obtaining an emission set corresponding to each discrete emission moment by using an emission opportunity search algorithm at a fixed emission moment according to the constraint conditions of the detection task;

s23, judging whether the transmitting set corresponding to each discrete transmitting moment is an empty set; if the transmission set corresponding to the discrete transmission moment is an empty set, executing the step S24; if the emission set corresponding to the discrete emission time is not an empty set, executing step S25;

s24, setting a corresponding mark, and enabling the numerical value of the mark to be-1;

s25, setting a corresponding mark, and enabling the numerical value of the corresponding mark to be 1;

step S26, detecting whether the signs of any two adjacent transmitting moments are different signs or not;

step S27, if the signs of two adjacent transmitting moments are different, determining the boundary point of a time window on a transmitting time dimension contained in an interval formed by the two adjacent transmitting moments through a dichotomy;

and S28, determining a time window on the emission time dimension according to all the obtained boundary points.

Further, step S3 includes repeating the following processing steps of the transmit opportunity search algorithm for fixed transmit instants until each transmit instant in the time window in the transmit time dimension is traversed:

step S31, according to the emission time T of the interplanetary detector _launch Determining a potential reachable area on the orbit of the target planet by using orbit elements of the earth and the target planet at the launching moment and launching energy constraint;

step S32, obtaining a first set of transfer flight time corresponding to the current transmitting moment according to the position relation between the target planet and the potential reachable region at the transmitting moment and the transfer flight time constraint;

and S33, obtaining an emission set corresponding to the current emission time by using a multi-boundary point search method for the first set of the transfer flight time.

The method for searching for the transmission opportunity at the fixed transmission time is to search for the transmission opportunity in the transfer flight time dimension under the condition of the given transmission time so as to determine all the transmission opportunities corresponding to the transmission time, namely the whole transmission set. Each subset of the transmit set is referred to as a time window in the transfer time-of-flight dimension.

Specifically, step S31 includes the steps of:

step S311, obtaining the variation range of the relative orbital inclination angle of the sun-center transfer orbital plane of the interplanetary detector relative to the earth orbital plane according to the orbital elements of the earth and the target planet at the launching moment and the maximum launching energy constraint provided by the last stage of the carrier rocket;

specifically, referring to fig. 4, in the present embodiment, an orbital coordinate system oxyz is introduced, the coordinate origin o is located at the center of the sun, the ox axis is positive along the centroid radial direction of the earth at the current time, the direction from the center of the sun to the earth is pointed, the oz axis is perpendicular to the earth orbit plane, the momentum moment vector direction along the earth orbit is positive, and the oy axis is determined by the right-hand rule.

At the moment of emission, the earth's vector r is set in the orbital coordinate system oxyz ₁ ＝[r ₁ ,0,0] ^T (corresponding to point P) ₁ ) Velocity v ₁ ＝[v _1x ,v _1y ,0] ^T Earth orbitMomentum moment vector h of road _E ＝[0,0,h _E ] ^T The launching velocity pulse delta v = [ delta v ] provided by the last stage of the carrier rocket for the interplanetary detector _x ,Δv _y ,Δv _z ] ^T Velocity v of the instantaneous interplanetary probe after application of the transmit velocity pulse _D The moment vector h of momentum of the sun-center transfer orbit of the interplanetary detector _D ＝[h _Dx ,h _Dy ,h _Dz ] ^T Determined by equation (1):

h _D ＝r ₁ ×v _D ＝r ₁ ×(v ₁ +Δv)＝-r ₁ Δv _z j+(h _E +r ₁ Δv _y )k (1)

in the formula (1), i, j, and k are unit vectors in three coordinate axis directions of the orbital coordinate system oxyz.

Moment of momentum vector h according to transfer orbit _D And moment of momentum vector h of earth orbit _E ＝[0,0,h _E ] ^T Obtaining the relative orbital inclination angle i of the transfer orbital plane relative to the earth orbital plane _r . Specifically, as can be seen from equation (2):

according to the patent entitled "method and device for determining the reachable Domain of a spacecraft", it is known that the maximum emission energy C is _3max Relative track inclination i under limited conditions _r Has a variation range of [ -i _rmax ,i _rmax ]Wherein i is _rmax Determined by equation (3):

step S312, according to the inclination angle i of the relative orbit _r Obtaining two limit centroid transfer orbital planes of the interplanetary detector, wherein the two limit centroid transfer orbital planes comprise a negative orbital plane and a positive orbital plane;

in particular, the relative track inclination i _r The sun transfer orbital planes of the interplanetary detector are in one-to-one correspondence, and all the sun transfer orbital planes of the interplanetary detector are positioned at the inclination angles of-i relative to the orbit _rmax And i _rmax The two limit sun center transfer track surfaces are respectively called as a negative track surface and a positive track surface.

Step 313, intercepting two corresponding arc sections on the target planet track by the negative pole track surface and the positive pole track surface, and respectively taking the two arc sections as a potential reachable first area and a potential reachable second area;

here, the positive and negative orbital planes intercept two corresponding arcs on the target planetary orbital path, with the intersection of all of the transfer orbital planes with the target planetary orbital path lying on both arcs, so that for point P ₁ For the interplanetary probe to be fired, all the possible reachable position points on the target planetary orbit must lie on both arcs. Thus, these two arc segments are referred to as a potential reachable-one zone and a potential reachable-two zone, respectively, and the true prox angle ranges of points on the arc segments can be represented as [ θ ] respectively _1min ,θ _1max ]And [ theta ] _2min ,θ _2max ]Wherein, theta _1min 、θ _2min 、θ _1max And theta _2max Four intersections of the positive and negative track surfaces and the target track are shown in fig. 5. The actually feasible intersection position points of the interplanetary detector and the target planet are necessarily located in a potential reachable first area and a potential reachable second area.

In step S314, a union set of the potential reachable first area and the potential reachable second area is obtained to obtain a potential reachable area.

Here, the union of the potentially reachable one area and the potentially reachable two area is referred to as a potentially reachable area.

Specifically, step S313 includes the steps of:

step S3131, determining a first intersection point and a second intersection point of the positive orbital plane and the target planetary orbit, the first intersection point having a true proximity point angle on the target orbit

Indicating that the second intersection point is at its true point of approach on the target track

It is shown that, among others,

specifically, the moment of momentum vector h of the target planet orbit is calculated according to the orbit element of the target planet _T And eccentricity vector e _T . For the positive orbital plane, as known from the patent named "a method and apparatus for determining reachable domain of spacecraft", there is only one transfer orbit in the orbital plane, and the orbit is determined according to the earth's vector r ₁ ＝[r ₁ ,0,0] ^T Earth orbit moment of momentum vector h _E ＝[0,0,h _E ] ^T And maximum emission energy C _3max Obtaining the corresponding emission speed pulse of the transfer orbit

Representation in a track coordinate system. Specifically, with reference to equation (4):

moment vector of momentum of transfer orbit on positive orbital plane

Determined by equation (5):

according to the momentum moment vector of the transfer orbit on the orbit surface of the anode

And the moment of momentum vector h of the target planet orbit _T To obtain the first intersection (corresponding to the true proximal angle)

) Unit vector of the radial direction of the sun

Specifically, with reference to equation (6):

in the formula (6), the first and second groups,

according to the specific direction

And h _T The same direction relation is determined, namely according to the following steps:

determining

According to unit vector

And eccentricity vector e of target planetary orbit _T Determining true near point angle

And

specifically, with reference to equation (8):

step S3132, obtaining a true anomaly of two intersection points of the negative orbital plane and the target planetary orbital

And

wherein the content of the first and second substances,

and true anomaly angle theta of two intersections of the earth's orbital plane and the target planetary orbit _Emin And theta _Emax Wherein, theta _Emin ＜θ _Emax . The specific calculation method is similar to the method for calculating two intersection points of the positive orbit surface and the target planetary orbit, and is not described herein again.

Step S3133, according to the intersection point θ _Emin And

and

determining a potential reachable region [ theta ] _1min ,θ _1max ]And potentially reachable two zones [ theta ] _2min ,θ _2max ]。

Specifically, there are two distribution cases of the potentially reachable areas on the target track, specifically referring to fig. 6, where fig. 6 (a) is a first distribution case and fig. 6 (b) is a second distribution case.

In FIG. 6 (a), θ _Emin Is located at

And

in between, i.e

The boundaries of the potential reachable one area and the potential reachable two area are then determined by equation (9) and equation (10), respectively:

in FIG. 6 (b), θ _Emin Is out of position

And

in between, i.e

The boundaries of the potential reachable one area and the potential reachable two area are then determined by equation (11) and equation (12), respectively:

in the formula (11), it is apparent that _1min >θ _1max At this time, the true paraxial region [ theta ] of the potential reachable region _1min ,θ _1max ]In fact the union of two intervals, i.e.

However, for consistency in representation, the interval [ θ ] is used _1min ,θ _1max ]Indicates a potentially accessible region, which has the meaning shown in formula (13).

The potential reachable area gives a target planet track which can be reached by the interplanetary detectorAll the position points on the road, the corresponding intersection position point of any transmitter is positioned in the potential reachable area. However, for a transmit opportunity, the detector is from the point of emission P ₁ Terminal point P of flying to target orbit ₂ Must equal the movement of the target from the initial position point of the moment of emission to the point P ₂ The time required. From this point, the end point P is once reached ₂ It is determined that all corresponding transfer times of flight can be moved by the target from the initial position point to the position point P ₂ Is determined. Thus, location points in the potentially reachable region can be associated with all corresponding transition times-of-flight and then a transition time-of-flight constraint can be added to reduce the search space.

Further, step S32 includes the steps of:

step S321, for any point in the potential reachable area, acquiring the movement time of the target planet moving to the position point in one orbit period by using a Kepler equation, and representing the position point by using the movement time, wherein the movement time is the transfer flight time of the detector when the position point is taken as an intersection point;

specifically, when the transfer flight time does not exceed one target orbit period, any one position point on the target orbit corresponds to the time when the target planet moves to the position point in one orbit circle from the emission time of the interplanetary probe, and the movement time is the transfer flight time of the interplanetary probe required when the corresponding position point is taken as the encounter point of the target planet and the interplanetary probe. The corresponding position points can thus be represented by this movement time, so that the position points on the target trajectory correspond to the transfer times of flight of the interplanetary probe.

Is arranged at the emission time T of the interplanetary detector _launch On the target planetary orbit, the target is located at a point M ₀ And any one of the location points M ₁ The true proximal angles are respectively

And

the approximate point angle of the two points

And

can be determined by equation (14):

wherein, the first and the second end of the pipe are connected with each other,

is a point M _i The size of the sun radius of (a) _T And e _T Respectively the semimajor axis and the eccentricity of the target track,

and

in the same quadrant.

Placing the target planet at the target location point M ₀ Moves to any position point M in a track ring along the track winding direction ₁ Is recorded as the transfer time of flight

From the Kepler (Kepler) equation:

wherein the content of the first and second substances,

is the mean motion of the target orbit, mu _s Is the constant of solar gravity.

By using the method, the time of the target planet moving to any position point on the target orbit in one orbit circle from the emission moment of the interplanetary detector can be determined, and the corresponding position point on the target orbit can be represented by the movement time (namely the transfer flight time of the detector), wherein the movement time is the transfer flight time of the detector when the corresponding position point is taken as an intersection point.

Step S322, when the movement time of the target planet does not exceed a target orbit period, representing the potential reachable area by using the set of the movement time corresponding to all the position points in the potential reachable area;

specifically, on the target orbit, there are three cases of the positional relationship between the target planet and the potential reachable region, as shown in fig. 7, where fig. 7 (a) is a case where the target position point is within the potential reachable-one region, fig. 7 (b) is a case where the target position point is within the potential reachable-two region, and fig. 7 (c) is a case where the target position point is outside the potential reachable region.

In fig. 7 (a), the potentially reachable zone can be moved with the target planet from the emission time of the detector within one orbital circle to the set of movement times of all position points within the potentially reachable zone, i.e. the union of two time intervals

Is represented by, wherein, T _T Is the track period of the target track. The potential reachable two-zone can be set by the motion time of the target planet from the emission moment of the detector to all position points in the potential reachable two-zone in one orbit circle

And (4) showing.

Similarly, in FIG. 7 (b), a potentially reachable region is available

Indicating that a potentially reachable two zone is available

And (4) showing.

Similarly, in FIG. 7 (c), there is a potentialReachable one and potentially reachable two zones are separately available

And

and (4) showing.

The above gives an indication of the motion time corresponding to a potentially reachable region when the target planet motion time (i.e. the transfer flight time of the detector) does not exceed one target orbit period.

Step S323, for the situation that the transfer flight time of the detector is not limited, namely the target planet can arrive at any point in the potential reachable area through any multi-circle flight, the motion time corresponding to the potential reachable area when the motion time of the target planet does not exceed one orbit period is used for representing, a set of all motion times of the target planet corresponding to the potential reachable area under the multi-circle situation is obtained, and the set of all motion times of the target planet is used as a set of all transfer flight times of the interplanetary detector;

in particular, when the transfer flight times of the detectors are unlimited, any one location point in the potentially reachable region corresponds to an infinite number of transfer flight times. Assuming a location point P in the potentially reachable region when the transition flight time does not exceed a target orbital period ₂ Corresponding transfer time of flight t _f0 When the transfer flight time is not limited, all the transfer flight times corresponding to the location point can be represented as t _f ＝t _f0 +k·T _T K =0,1,2, …. Accordingly, the transfer time-of-flight set TF corresponding to the potentially reachable region ₀ May be represented as a union of multiple time intervals. Taking the case shown in fig. 7 (a) as an example, when there is no limitation on the transition flight time, the set of transition flight times corresponding to the potential reachable regions can be represented as:

for the cases shown in FIGS. 7 (b) and 7 (c), the pair of potential reachable regionsCorresponding transfer time-of-flight set TF ₀ The calculation method (c) is similar to that shown in fig. 7 (a), and is not described herein again.

Step S324, according to the set TF of all the transfer flight times corresponding to the potential reachable area under the condition of multi-turn ₀ And constraint of transfer flight time, and obtaining a first set TF of the transfer flight time corresponding to the current emission moment.

In particular, the constraint on the transfer flight time, i.e. t, of the interplanetary probe mission is taken into account _f ∈[T _fmin ,T _fmax ]Current transmission time T _launch The corresponding first set of transfer times-of-flight that satisfy the transfer time-of-flight constraint may be represented by equation (17):

TF＝TF ₀ ∩[T _fmin ,T _fmax ] (17)

in general, the first set of transition flight times TF is composed of a plurality of different time intervals, wherein each time interval is referred to as a subset of the TF.

Further, step S33 includes the steps of:

step S331, for each subset of the first set of the transfer flight time, based on the emission energy constraint, obtaining a encounter set subset contained in the subset by using a multi-boundary point search method, and performing union set on all the encounter set subsets contained in the first set of the transfer flight time to obtain a whole encounter set;

step S332, for each subset of the encounter set, based on the size constraint of the braking speed pulse, obtaining an intersection set subset contained in the encounter set subset by using a multi-boundary point search method, and performing union on all the intersection set subsets contained in the encounter set to obtain the whole intersection set;

step S333, for each subset of the rendezvous set, based on the constraint conditions of measurement and control and communication distance, obtaining the emission set subset contained in the rendezvous set subset by using a multi-boundary point search method, and summing all the emission set subsets contained in the rendezvous set to obtain the whole emission set.

Here, the search processes of the above three steps are completely similar, except that the specific constraints considered in the multi-boundary point search method used in each step are different.

In particular, in order to obtain the emission instant T _launch The specific definitions of encounter set, rendezvous set and transmission set are presented below for all transmission opportunities.

Maximum launch energy C provided at the last stage of the launch vehicle _3max Under the limiting condition, if the interplanetary detector is at T _launch Time of flight, passing transfer time of flight t _f Later, when encountering the target planet, t _f Referred to as and transmission time T _launch The corresponding encountered transition flight time, referred to as the encountered transition flight time. In the transfer-time-of-flight set TF, the set of all the encountered transfer times is called the transmission instant T _launch The corresponding encounter set, abbreviated as "encounter set", is denoted as TF _I 。

Obviously, in the encounter set, any one of the transition flight times corresponds to a unique encounter point between the detector and the target planet on the target orbit, and the corresponding transmit velocity pulse satisfies the transmit energy constraint. The set of all encounter location points on the target track corresponding to the encounter set is called an encounter zone. It is contemplated that any point in the encounter area is accessible to the detectors located at the emission points, and thus, the encounter area must be located within a potentially accessible area.

It should be noted that there is not a one-to-one correspondence between the transition flight times of the encounter concentration and the encounter points in the encounter zone. Generally, one transition flight time in the encounter set necessarily corresponds to a unique encounter point, while one encounter point in the encounter zone may correspond to multiple transition flight times in the encounter set, each of which may differ by an integer number of target track cycles T _T 。

Maximum launch energy C provided at the last stage of the launch vehicle _3max Under the limiting condition, if the interplanetary detector is at T _launch Time of flight, start orbit transfer, and pass through time of flight t _f Then, meeting with the target planet, and meeting the required meeting braking speed pulse to meet the braking speed pulse size constraint when meeting, then t _f Called and transmission time T _launch Corresponding rendezvous and transfer flight time, referred to as rendezvous and transfer flight time for short. In the set of transfer times of flight TF, the set of all the rendezvous transfer times of flight is called the transmission instant T _launch The corresponding rendezvous set, abbreviated as rendezvous set, is denoted as TF _II 。

In the rendezvous set, any one of the transfer flight times also corresponds to a unique rendezvous position point of the detector and the target planet on the target orbit. The set of all the rendezvous position points on the target track corresponding to the rendezvous set is called a rendezvous zone. Obviously, the meeting areas corresponding to the same transmission time must be located in the corresponding meeting areas.

Maximum launch energy C provided at the last stage of the launch vehicle _3max Under the limiting condition, if the interplanetary detector is at T _launch Time of flight, passing transfer time of flight t _f Then, meeting with the target planet, and when meeting, the needed meeting brake speed pulse meets the brake speed pulse size constraint, the relative distance between the earth and the detector meets the measurement and control and communication distance constraint, then t _f Referred to as and transmission time T _launch Corresponding transmittable transfer flight time, abbreviated transmittable transfer flight time. In the set of transfer times of flight TF, the set of all transmittable transfer times of flight is called the transmission instant T _launch The corresponding transmission set, abbreviated as TF _III 。

Similarly, the set of all position points on the target track corresponding to the emission set is called an emission area. It is known that the transmitting regions corresponding to the same transmitting time must be located in the corresponding intersection regions.

According to the encounter set TF _I TF of rendezvous set _II And emission set TF _III The definition of (a) can be known,

and the relationship between these several sets can be referred to in figure 8. Emission set TF _III I.e. the transmission time T _launch All corresponding transmission opportunities. To obtain the emission set, the maximum emission energy C of the interplanetary sounding mission can be determined _3max Restraint, braking speed pulse sizeThe constraint, the measurement and control and the communication distance constraint are gradually added into the process of searching the transmitter opportunity, the search space is continuously reduced, and finally the transmission time T is obtained _launch All corresponding transmitting opportunities satisfying the constraints.

For each of the above three constraints, the search space (TF, TF) is paired _I Or TF _II ) When searching, a multi-boundary point searching method can be adopted. To solve the encounter set TF from the transfer time-of-flight set TF _I For example, the set of transfer times of flight TF is generally composed of a plurality of different time intervals, i.e. subsets. For any subset of TF, the emission time of the detector is T _launch The maximum allowable emission energy is C _3max Such that all transition flight times in the subset that satisfy the maximum transmit energy constraint constitute successive time intervals, each time interval being subject to the TF set _I A subset of (a). Obviously, only all TF contained in each subset of TF need be found _I Subset, the entire encounter set TF is obtained _I 。

Specifically, step S331 includes the steps of:

step S3311, for any subset of the first set TF of the transfer flight time, determining a search step length;

specifically, let [ t _{f_min} ,t _{f_max} ]For transferring any subset of the first set of times of flight TF, according to the time interval t _{f_min} ,t _{f_max} ]Selecting a search step length, which is specifically determined by formula (18):

wherein min {. Denotes the smallest element in the set; tau is ₀ ＝(t _{f_max} -t _{f_min} ) N; n is a small positive integer, which may be taken as 16, to realize the time interval t _{f_min} ,t _{f_max} ]Fast search with large step length; tau is _S For a set fixed step size, called the sensitive step size, for controlling the search step sizeτ is such that it does not exceed the maximum step length τ allowed at all times _S Thereby controlling the fineness of the search.

Step S3312, in the subset, selecting each transfer flight time according to the search step length, and recording the number of the selected transfer flight times as Q;

in particular, if the time interval [ t ] _{f_min} ,t _{f_max} ]If the interval length is not an integral multiple of the search step length tau, then the time interval t is selected _{f_min} ,t _{f_max} ]Internal transfer time of flight t _f,k ＝t _{f_min} + k · τ, (k =0,1,2, …, q) and t _f,q+1 ＝t _{f_max} Wherein q = int [ (t) _{f_max} -t _{f_min} )/τ]，int[·]Expressing taking an integer;

if the time interval t _{f_min} ,t _{f_max} ]Is an integer multiple of the search step τ, the time interval t is selected _{f_min} ,t _{f_max} ]Internal transfer time of flight t _f,k ＝t _{f_min} + k · τ, (k =0,1,2, …, q), where q = (t) _{f_max} -t _{f_min} )/τ。

Step S3313, calculating the emission energy corresponding to each transfer flight time by using Lambert algorithm;

step S3314, judge whether the emission energy corresponding to each transfer flight time meets the emission energy constraint; if the transmission energy corresponding to the transfer flight time does not meet the transmission energy constraint, executing step S3315; if the transmission energy corresponding to the transfer flight time meets the transmission energy constraint, executing step S3316;

specifically, T is _launch The position point P of the earth at the moment ₁ As the emission point of the interplanetary probe, the transit time of flight t in the encounter zone _f,k Corresponding position point P _2,k As end point of the detector track transfer, t _f,k The required transmit velocity pulse Δ v is calculated as the transition time of flight of the detector using Lambert's algorithm. If it is

Then t _f,k Is oneThe transfer time-of-flight may be encountered to satisfy the transmit energy constraint, otherwise, it may not be encountered to satisfy the transmit energy constraint.

Step S3315, setting a corresponding mark, and enabling the value of the mark to be-1;

step S3316, setting a corresponding mark, and enabling the value of the mark to be 1;

step S3317, detecting whether the marks corresponding to any two adjacent transfer flight times are different in sign; if the marks corresponding to the two adjacent transfer flight times are different in sign, determining the boundary point of the encountered set subset contained in the interval formed by the two adjacent transfer flight times through a dichotomy;

specifically, if two adjacent flags Flag _j (j is more than or equal to 0 and less than or equal to Q-2) and Flag _j+1 Different sign, then in the corresponding time interval [ t ] _f,j ,t _f,j+1 ]Within this, there must be one boundary point that encounters a subset of the set, and that boundary point can be determined using a dichotomy.

Step S3318, determining the encounter set subset contained in the subset of the first set of the transition flight time according to all the acquired encounter set subset boundary points;

step S3319, repeatedly executing steps S3311 to S3318 until all the encounter set subsets included in the first set of transition flight times are obtained;

step S33110, summing the encounter set subsets contained in all the subsets of the first set of the transition flight times to obtain the whole encounter set TF _I 。

It should be noted that the method for solving the transition flight time interval t by using the multi-boundary point search method _{f_min} ,t _{f_max} ]When the encountered subset is within the encountered subset, if the interval length of one encountered subset is less than τ and the subset is just within the flight time of two adjacent transitions selected, as shown in the encountered subset TF in fig. 9 _{I_B} As shown, this subset will be missed during the search (it should be noted that this is the only situation that one might miss encountering a subset of the set). However, since the time length of the missing subset is small (smaller than the sensitivity step τ) _S ) So that it can be ignoredAnd omitted. It can be seen that the sensitivity step τ is _S Which gives the maximum length of time that the subset of encounter sets are allowed to be missed during the search.

Further, in step S332, using the multi-boundary point search method, the encounter set TF may be calculated _I All subsets of the rendezvous set contained in the subsets of (1), thereby obtaining the whole rendezvous set TF _II . In view of

In the multi-boundary point search method, when judging whether the selected transfer flight time can meet the transfer flight time, only the judgment that whether the braking speed pulse required by the detector when meeting the target planet meets the braking speed pulse size constraint (namely, the relative speed size constraint during meeting) is needed.

Further, in step S333, the rendezvous set TF can be calculated by using the multi-boundary point search method _II All subsets of the transmit set contained within the respective subsets of (a) to obtain the entire transmit set TF _III . In view of

In the multi-boundary point search method, when judging whether the selected transfer flight time can transmit the transfer flight time, only judging whether the relative distance between the intersection detector and the earth meets the measurement and control and communication distance constraint. Emission set TF _III I.e. a fixed transmission time T _launch All corresponding transmission opportunities.

The specific calculation method of the rendezvous set and the emission set is similar to that of the encounter set, and is not described herein.

As can be seen from the above calculation process of the emission set, the whole calculation process involves the concept of several location areas: potentially reachable, encountered, rendezvoused, and transmitted areas. Taking the case where the target location point is located within the potentially reachable area as shown in fig. 7 (a) as an example, the relationship between these several location areas is shown in fig. 10. These several location areas are located on the target track. The potential reachable first area and the potential reachable second area are two corresponding arc sections intercepted on the target track by the anode track surface and the cathode track surface, and the two areas are actually a set of intersection points of all feasible transfer track surfaces of the interplanetary detector and the target track; each subset of encounter zones is located within a potentially reachable one zone and a potentially reachable two zone, wherein there is one subset of encounter zones within the potentially reachable one zone (encounter zone subset 3), there are two subsets of encounter zones within the potentially reachable two zones (encounter zone subsets 1 and 2), and the union of all the subsets of encounter zones is the entire encounter zone; in the encounter area subset 1, there is no cross area subset, and in the

encounter area subsets

2 and 3, there is one cross area subset (cross area subsets 1 and 2), and the union of all the cross area subsets is the whole cross area; in intersection subset 1 there is one subset of transmission zones, while in intersection subset 2 there is no subset of transmission zones, so the whole transmission zone is located in intersection subset 1.

Example two:

taking the intersection detection of the small near-earth planet 4660Nereus as an example, the embodiment of the present invention provides a comparative simulation result of performing a transmission opportunity search by using a commonly used Pock-Chop diagram method and the two-dimensional transmission window method proposed by the present invention, and specifically refer to fig. 11 to 16.

Asteroid 4660Nereus was the detection target of the Japanese MUSES-C detector, belongs to Apollo class in the asteroid in the near field, and the orbit information thereof is shown in Table 1 (published by German space center DLR):

TABLE 1

Track element	The earth	4660Nereus
			Semi-major axis a/(AU)	1.00000011	1.48868
Eccentricity e	0.01671022	0.35992
			Track inclination i/(°)	0.00005	1.42386
Rising point Chijing omega/(°)	348.73936	314.550
			Argument of perigee w/(°)	114.20783	157.882
Mean angle of approach M/(°)	357.51716	270.463
			Epoch time/(Ru-zong day)	2451545	2453450.5

The constraints to be satisfied by the intersection detection task with the near-earth asteroid 4660Nereus are set as follows:

(a) The expected emission time period of the asteroid probe from the earth is from 2019.1.112 to 2022.12.3112 UT;

(b) Transfer flight time t of detector and asteroid intersection _f Is expected to be in the range of [150,1500](days);

(c) Launch vehicle for launching a probeMaximum emission energy C provided by stage _3max ＝36km ² /s ² ；

(d) The size of the braking speed pulse needed to be applied by the detector during intersection | | Deltav _R ||≤ΔV _D ＝2.0km/s；

(e) The relative distance between the detector and the earth does not exceed R during intersection _max ＝4×10 ⁸ km。

According to the constraint conditions, all transmitting opportunities meeting all the constraint conditions are calculated by utilizing a Pock-Chop graph method. For this reason, the time-of-flight range [150,1500 ] is shifted from UT at expected emission period 2019.1.112 to UT at 2022.12.3112]And (d) performing traversal search, wherein the traversal step length is 1 day, and respectively drawing a transmitting energy contour map, a crossing braking speed pulse contour map and a relative distance contour map of the detector and the earth during crossing by using traversal results. These three contour plots are shown in FIGS. 11, 12 and 13, respectively, where the units of the marker values are km, respectively ² /s ² Km/s and 10 ⁸ km。

As can be seen in FIG. 11, the emission energy for each point within the emission energy contour, labeled 36, is less than C _3max I.e. that each point inside is feasible for the last stage of the launch vehicle. As can be seen from FIG. 12, the braking speed pulse sizes for each point within the braking speed pulse contour labeled 2 are all less than Δ V _D I.e. points inside are feasible for the detector. The transmit energy contour labeled 36, the brake speed pulse contour labeled 2, and the relative distance contour labeled 4 are plotted into one graph, as shown in fig. 14. In FIG. 14, there are 6 relative distance contours, denoted by L, labeled 4 _i (i =1,2, …, 6). From the distribution and variation of the relative distance contours (fig. 13), the intersection of the area bounded by the emission energy contour, labeled 36, and the braking speed pulse contour, labeled 2, is at L ₂ And L ₃ And L ₄ And L ₅ All the constraints of the probing task are satisfied by the sections in between. In fact, the traversal results from the Pock-Chop graph method can satisfy various constraintsPoint of condition (T) _launch ,t _f ) The set of (c) is shown as the shaded area in fig. 14, which is all the calculated transmission opportunities. The whole shadow region contains 5 sub-regions, namely A ₀ 、B ₀ 、C ₀ 、D ₀ And E ₀ Wherein A is ₀ 、B ₀ And C ₀ Three sub-regions are larger, and D ₀ And E ₀ Two sub-regions are smaller and an enlargement of these two sub-regions is shown within the dashed box in fig. 14. It is clear that the entire shaded area is determined entirely by the transmitted energy contour, labeled 36, the brake speed pulse contour, labeled 2, and the relative distance contour, labeled 4. The computation time for searching all transmission opportunities using the Pock-Chop graph method is 225.392s.

When searching all transmitting opportunities by adopting the proposed two-dimensional transmitting window method, the searching step length tau of the transmitting time dimension is taken _launch =10 days, in the expression of the search step τ in the transfer flight time dimension (equation (18)), take the sensitivity step τ _S =5 days, positive integer n =16, all searched transmission opportunities are shown as shaded areas in fig. 15. As can be seen from fig. 15, all the transmitter opportunities searched by the two-dimensional transmit window method also include 5 sub-regions, i.e., A, B, C, D and E, which correspond to the sub-region a in fig. 14 respectively ₀ 、B ₀ 、C ₀ 、D ₀ And E ₀ . Fig. 16 shows an enlarged view of the 5 subregions A, B, C, D and E, where fig. 16 (a) corresponds to subregion a, fig. 16 (B) corresponds to subregion B, fig. 16 (C) corresponds to subregion C, fig. 16 (D) corresponds to subregion D, and fig. 16 (E) corresponds to subregion E. As can be seen from fig. 16, the boundaries of the 5 sub-regions almost coincide with the contour lines determined by the constraints, which indicates that the calculation results of the sub-regions are very accurate. The calculation time for searching for a transmitter opportunity using the two-dimensional transmission window method is 5.522s.

In conclusion, the two-dimensional transmission window method has accurate calculation results, and compared with the currently commonly adopted Pock-Chop graph method, the two-dimensional transmission window method greatly improves the search efficiency, reduces the calculation amount, and can shorten the search time of the transmission opportunity by about two orders of magnitude. In addition, in the two-dimensional emission window method, the time windows in two search dimensions of emission time and transfer flight time are obtained through search iteration, so that the boundary of the time window can be accurately obtained by controlling iteration errors, which is difficult to realize by the Pock-Chop graph method. Therefore, the two-dimensional emission window method is not only suitable for determining the emission window of a specific interplanetary detection task, but also suitable for searching and evaluating the large-scale, high-precision and quick emission opportunities of the target planet.

Example three:

the embodiment of the invention provides a schematic diagram of a quick searching device for an interplanetary detector transmitting opportunity, as shown in fig. 17.

Referring to fig. 17, the apparatus includes:

the acquisition unit is used for acquiring target planet orbit elements and constraint conditions of the interplanetary exploration task;

the transmitter opportunity searching unit is used for determining a time window of a transfer flight time dimension corresponding to the given transmitting moment according to the constraint condition of the detection task;

the time window searching unit of the emission time dimension is used for determining the time window of the emission time dimension according to the target planet orbit element and the constraint condition of the detection task;

and the traversing unit is used for traversing the time windows in the emission time dimension, and determining the time window in the transfer flight time dimension corresponding to each emission moment in each time window, so that all emission opportunities are obtained.

The embodiment of the invention further provides electronic equipment, which comprises a memory, a processor and a computer program which is stored on the memory and can run on the processor, wherein the processor executes the computer program to realize the steps of the rapid search method for the interplanetary detector transmitting opportunity provided by the embodiment.

The embodiment of the invention also provides a computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the steps of the fast search method for the interplanetary probe transmitter opportunity provided by the embodiment are executed.

The computer program product provided in the embodiment of the present invention includes a program code and a computer-readable storage medium, where instructions included in the program code may be used to execute the method described in the foregoing method embodiment, and specific implementation may refer to the method embodiment, and details are not described here.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the system and the apparatus described above may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In addition, in the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for fast search of interplanetary probe transmission opportunities, the method comprising:

traversing the time windows on the emission time dimension by using the emitter opportunity search algorithm of the fixed emission time, and determining the time window on the transfer flight time dimension corresponding to each emission time in each time window so as to obtain all emitter opportunities;

determining a time window in a transmission time dimension by using a multi-boundary point search method and combining a transmission opportunity search algorithm at a fixed transmission moment according to the constraint condition of the detection task, wherein the determining comprises the following steps:

selecting each discrete transmitting moment with a larger searching step length in a transmitting time period;

obtaining an emission set corresponding to each discrete emission moment by utilizing an emission opportunity search algorithm at the fixed emission moment according to the constraint condition of the detection task;

judging whether the transmitting set corresponding to each discrete transmitting moment is an empty set;

if the emission set corresponding to the discrete emission time is the empty set, setting a corresponding mark, and enabling the numerical value of the mark to be-1;

if the transmitting set corresponding to the transmitting moment is not the empty set, setting the corresponding mark and enabling the numerical value of the mark to be 1;

detecting whether the marks of any two adjacent transmitting moments are different in sign;

if the signs of the two adjacent transmitting moments are different, determining the boundary point of a time window on a transmitting time dimension contained in an interval formed by the two adjacent transmitting moments through a dichotomy;

determining a time window on the emission time dimension according to all the obtained boundary points;

traversing the time windows in the emission time dimension by using the emission opportunity search algorithm at the fixed emission time, and determining the time window in the transfer flight time dimension corresponding to each emission time in each time window, thereby obtaining all emission opportunities, wherein the following emission opportunity search algorithm at the fixed emission time is repeatedly executed until each emission time in the time windows in the emission time dimension is traversed:

determining a potential reachable area on the orbit of a target planet according to the launching moment of a interplanetary detector, the orbit elements of the earth and the target planet at the launching moment and the launching energy constraint;

obtaining a first set of transfer flight time corresponding to the current transmitting moment according to the transmitting moment, the position relation between the target planet and the potential reachable area and transfer flight time constraint;

and for the first set of the transfer flight time, obtaining an emission set corresponding to the current emission time by using the multi-boundary point search method.

2. The method for fast search of interplanetary probe transmit opportunities according to claim 1, characterized in that the constraints of the probing task include time node constraints including an allowed transmit time period and a transfer flight time period, energy constraints including a transmit energy constraint and a brake speed pulse size constraint, and measurement and control and communication distance constraints.

3. The method for fast search of interplanetary probe transmitter opportunities according to claim 1, wherein the determining the potentially reachable region on the target planetary orbit according to the interplanetary probe's transmit time, the orbit elements of the earth and the target planetary at the transmit time, and the transmit energy constraints comprises:

obtaining the variation range of the relative orbital inclination angle of the sun-center transfer orbital plane of the interplanetary detector relative to the earth orbital plane according to the orbital elements of the earth and the target planet at the launching moment and the maximum launching energy constraint provided by the last stage of the carrier rocket;

obtaining two limit centroid transfer orbital planes of the interplanetary detector according to the variation range of the relative orbit inclination angle, wherein the two limit centroid transfer orbital planes comprise a negative orbital plane and a positive orbital plane;

intercepting two corresponding arc sections on a target planetary orbit by the negative orbit surface and the positive orbit surface, wherein the two corresponding arc sections are respectively called a potential reachable first area and a potential reachable second area;

and obtaining the potential reachable area according to the potential reachable one area and the potential reachable two area.

4. The method for fast searching for the interplanetary probe transmitting opportunity according to claim 1, wherein the obtaining a first set of transfer flight times corresponding to a current transmitting time according to a position relationship between the target planet and the potential reachable region at the transmitting time and a transfer flight time constraint comprises:

for any point in the potential reachable area, acquiring the movement time of the target planet to the position point in one target orbit period by using a Kepler equation, and representing the position point by using the movement time, wherein the movement time is the transfer flight time of the detector when the position point is taken as an intersection point;

representing the potential reachable region with a set of motion times corresponding to all location points in the potential reachable region;

obtaining a set of all motion times of the target planet corresponding to the potential reachable area under the condition of multiple circles by using the motion time representation corresponding to the potential reachable area when the motion time of the target planet does not exceed the target orbit period, and taking the set of all motion times of the target planet as a set of all transfer flight times of the interplanetary detector;

and obtaining a first set of the transfer flight time corresponding to the current transmitting moment according to the set of all the transfer flight times corresponding to the potential reachable area under the multi-turn condition and the transfer flight time constraint.

5. The method for fast searching for interplanetary probe transmitting opportunities according to claim 1, wherein the obtaining of the transmitting set corresponding to the current transmitting time by using the multi-boundary point search method for the first set of the transfer flight time comprises:

for each subset of the first set of transition flight times, based on the emission energy constraint, obtaining a subset of encounter sets contained in the subset by using the multi-boundary point search method, and performing union on all the subsets of the encounter sets contained in the first set of transition flight times to obtain a whole encounter set;

for each subset of the encounter set, based on the braking speed pulse size constraint, obtaining an intersection set subset contained in the encounter set subset by using the multi-boundary point search method, and performing union on all the intersection set subsets contained in the encounter set to obtain a whole intersection set;

and for each subset of the rendezvous set, based on the measurement and control and communication distance constraint conditions, obtaining a transmitting set subset contained in the rendezvous set subset by using the multi-boundary point search method, and summing all the transmitting set subsets contained in the rendezvous set to obtain the whole transmitting set.

6. The method for fast search of interplanetary probe transmit opportunities according to claim 5, wherein the obtaining, for each subset of the first set of transition flight times, a subset of encounter sets included in the subset using the multi-boundary point search method based on the transmit energy constraint, and merging all subsets of the encounter sets included in the first set of transition flight times to obtain the entire encounter set comprises:

determining a search step size for each subset of the first set of transition flight times;

selecting each transfer flight time in the subset according to the search step length;

calculating the emission energy corresponding to each transfer flight time by utilizing a Lambert algorithm;

judging whether the emission energy corresponding to each transfer flight time meets the emission energy constraint;

if the emission energy corresponding to the transfer flight time does not meet the emission energy constraint, setting a corresponding mark, and enabling the value of the mark to be-1;

if the emission energy corresponding to the transfer flight time meets the emission energy constraint, setting a corresponding mark, and enabling the value of the mark to be 1;

detecting whether marks corresponding to any two adjacent transfer flight times are different in sign;

if the marks corresponding to the two adjacent transfer flight times are different in sign, determining the boundary point of a encountered set subset contained in an interval formed by the two adjacent transfer flight times through a dichotomy;

determining a encounter set subset contained in the subset of the first set of transition flight times according to the obtained boundary points of all the encounter set subsets;

and merging all the subsets of the first set of the transfer flight times to obtain the whole encounter set.

7. An apparatus for fast search of interplanetary probe transmission opportunities, the apparatus comprising:

the acquisition unit is used for acquiring target planet orbit parameters and constraint conditions of the interplanetary exploration task;

a transmitter opportunity search unit with fixed transmission time, which is used for determining a time window of a transfer flight time dimension corresponding to the given transmission time according to the constraint condition of the detection task;

the traversing unit is used for traversing the time windows in the emission time dimension, and determining the time window in the transfer flight time dimension corresponding to each emission moment in each time window so as to obtain all emission opportunities;

the time window search unit of the emission time dimension is specifically configured to:

judging whether the emission set corresponding to each discrete emission moment is an empty set;

detecting whether the signs of any two adjacent transmitting moments are different signs or not;

the traversal unit includes: repeatedly performing the following fixed transmission moment transmission opportunity search algorithm until each transmission moment in a time window in the transmission time dimension is traversed:

obtaining a first set of transfer flight time corresponding to the current transmitting moment according to the transmitting moment, the position relation between the target planet and the potential reachable region and transfer flight time constraint;