On-orbit autonomous task planning method, device and equipment for imaging earth target

Abstract

The application provides an on-orbit autonomous task planning method, device and equipment for imaging a ground target, and relates to the technical field of spaceflight. The method comprises the following steps: fitting each strict regression orbit of a ground observation satellite to obtain a target function corresponding to each strict regression orbit; based on the position information of a specified target observation point and the orbit parameters of each strict regression orbit, a virtual orbit passing through the target observation point is constructed to determine a latitude depression angle sequence corresponding to the ground observation satellite when the ground observation satellite runs on each virtual orbit and passes through the target observation point; an initial reference orbit point is determined based on the latitude depression angle sequence through the target function, and the initial reference orbit point is compensated for multiple times to obtain a target reference orbit point; and if the target reference orbit point satisfies a preset observation constraint, a ground target imaging task can be executed. The application can significantly improve the satellite autonomy and task planning real-time performance in the process of planning a ground target imaging task.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of space technology, and in particular to a method, device and equipment for on-board autonomous task planning for imaging a target on the earth. BACKGROUND

[0002] Currently, a ground station plans a satellite's task for imaging a target on the earth. Specifically, the ground station plans position information and time information for observing a target observation point, and uploads the planning result to the satellite, thereby resulting in weak autonomy and real-time performance of planning the satellite's task for imaging a target on the earth. SUMMARY

[0003] Therefore, the present application aims to provide a method, device and equipment for on-board autonomous task planning for imaging a target on the earth, which can significantly improve the autonomy and real-time performance of planning a satellite's task for imaging a target on the earth.

[0004] In a first aspect, the present application provides a method for on-board autonomous task planning for imaging a target on the earth, which is applied to an earth observation satellite, and includes the following steps.

[0005] Fitting each strict regression orbit of the earth observation satellite, to obtain a target function corresponding to each strict regression orbit, which is used to describe a mapping relationship between position information of any orbit point in the strict regression orbit and a latitude depression angle;

[0006] Based on position information of a specified target observation point and orbit parameters of each strict regression orbit, a virtual orbit passing through the target observation point is constructed, to determine a latitude depression angle sequence corresponding to the earth observation satellite running on each virtual orbit and passing through the target observation point;

[0007] Based on the latitude depression angle sequence, an initial reference orbit point is determined from each strict regression orbit through the target function, and the initial reference orbit point is compensated for multiple times to obtain a target reference orbit point in each strict regression orbit, so that a vector formed by the target observation point and the target reference orbit point is perpendicular to a velocity vector of the earth observation satellite passing through the target reference orbit point;

[0008] If the target reference orbit point in each strict regression orbit meets a preset observation constraint, the earth observation satellite performs a task for imaging a target on the earth with respect to the target observation point when passing through the target reference orbit point.

[0009] In an implementation, the orbit parameters of the strict regression orbit include a semi-major axis, an eccentricity, an inclination, a perigee amplitude and a ascending node right ascension; and the construction of the virtual orbit passing through the target observation point based on the position information of the specified target observation point and the orbit parameters of each strict regression orbit includes the following steps.

[0010] For each strict regression orbit, keeping the semi-major axis, eccentricity, inclination, argument of perigee of the strict regression orbit unchanged, changing the longitude of ascending node of the strict regression orbit, and combining the position information of the specified target observation point, a virtual orbit passing through the target observation point is constructed.

[0011] In an embodiment, an initial reference orbit point is determined from each strict regression orbit based on the latitude and elevation angle sequence by a target function, comprising:

[0012] For each strict regression orbit, the latitude and elevation angle sequence is input into the target function corresponding to the strict regression orbit, so that the target function outputs the position information of the initial reference orbit point for the latitude and elevation angle sequence.

[0013] In an embodiment, the initial reference orbit point is compensated multiple times to obtain a target reference orbit point in each strict regression orbit:

[0014] The initial reference orbit point is compensated once based on the position information of the target observation point to obtain an intermediate reference orbit point in each strict regression orbit, so that the vector formed by the target observation point and the intermediate reference orbit point is perpendicular to the strict regression orbit to which the intermediate reference orbit point belongs;

[0015] The intermediate reference orbit point is subjected to offset processing to obtain an offset orbit point, the intermediate reference orbit point is compensated twice using the offset orbit point to obtain new position information of the intermediate reference orbit point, and the new intermediate reference orbit point is subjected to offset processing to obtain a new offset orbit point, until a preset loop termination condition is met, and the new intermediate reference orbit point obtained at the loop termination is taken as the target reference orbit point in the strict regression orbit.

[0016] In an embodiment, the initial reference orbit point is compensated once based on the position information of the target observation point to obtain an intermediate reference orbit point in each strict regression orbit, comprising:

[0017] The initial reference orbit point is compensated once based on the position information of the target observation point to obtain an intermediate reference orbit point in each strict regression orbit, comprising:

[0018] For each strict regression orbit, the initial reference orbit point corresponding to the once-compensated latitude and elevation angle is determined based on the position information of the target observation point and the orbit parameters of the strict regression orbit using a spherical triangle algorithm.

[0019] The once-compensated latitude and elevation angle is input into the target function corresponding to the strict regression orbit, so that the target function outputs the position information of the intermediate reference orbit point for the once-compensated latitude and elevation angle.

[0020] In an embodiment, the intermediate reference track point is offset to obtain an offset track point, the intermediate reference track point is compensated twice by using the offset track point to obtain position information of a new intermediate reference track point, including:

[0021] For each strict regression track, the intermediate reference track point is offset to obtain an offset track point, and the latitude and depression angle of the offset track point is input into a target function corresponding to the strict regression track, so that the target function outputs position information corresponding to the offset track point for the latitude and depression angle of the offset track point;

[0022] Based on the position information corresponding to the offset track point, a velocity vector of the earth observation satellite passing through the intermediate reference track point in the earth-fixed coordinate system is determined;

[0023] Based on the velocity vector, a projection of the vector formed by the intermediate reference track point and the offset track point in the velocity direction is determined to determine a twice-compensated latitude and depression angle, and the twice-compensated latitude and depression angle is input into the target function corresponding to the strict regression track, so that the target function outputs position information of a new intermediate reference track point for the twice-compensated latitude and depression angle.

[0024] In an embodiment, the preset observation constraint includes a preset latitude and longitude constraint and a preset side view angle constraint; if the target reference track point in each strict regression track satisfies the preset observation constraint, the earth observation satellite performs an earth target imaging task for a target observation point when passing through the target reference track point, including:

[0025] Determine the latitude and longitude information and the side view angle information of the target reference track point in each strict regression track;

[0026] If the latitude and longitude information of the target reference track point satisfies the preset latitude and longitude constraint, and the side view angle information of the target reference track point satisfies the preset side view angle constraint, it is determined that the earth observation satellite can observe the target observation point when passing through the target reference track point, and performs an earth target imaging task for the target observation point according to the latitude and longitude information and the side view angle information.

[0027] In a second aspect, the embodiments of the present application also provide an on-board autonomous task planning device for earth target imaging, which is applied to an earth observation satellite and includes:

[0028] A function fitting module is configured to fit each strict regression track of the earth observation satellite to obtain a target function corresponding to each strict regression track, the target function being configured to describe a mapping relationship between position information of any track point in the strict regression track and a latitude and depression angle;

[0029] a virtual orbit construction module configured to construct a virtual orbit passing through the target observation point based on position information of the target observation point and orbit parameters of the strict regression orbit of each orbit, so as to determine a corresponding latitude and elevation angle sequence of the earth observation satellite when passing through the target observation point on each virtual orbit;

[0030] a reference point determination module configured to determine an initial reference orbit point from the strict regression orbit of each orbit based on the latitude and elevation angle sequence through the target function, and to obtain a target reference orbit point in the strict regression orbit of each orbit by compensating the initial reference orbit point for multiple times, so that a vector formed by the target observation point and the target reference orbit point is perpendicular to a velocity vector of the earth observation satellite when passing through the target reference orbit point;

[0031] a task planning module configured to perform an earth target imaging task for the target observation point when the earth observation satellite passes through the target reference orbit point if the target reference orbit point in the strict regression orbit of each orbit satisfies a preset observation constraint.

[0032] In a third aspect, an embodiment of the present application further provides an electronic device, including a processor and a memory, the memory storing computer executable instructions capable of being executed by the processor, and the processor executes the computer executable instructions to implement the method of any one of the first aspect.

[0033] In a fourth aspect, an embodiment of the present application further provides a computer readable storage medium, the computer readable storage medium storing computer executable instructions, and the computer executable instructions, when called and executed by a processor, cause the processor to implement the method of any one of the first aspect.

[0034] The embodiment of the present application provides a kind of on-orbit autonomous task planning method, device and equipment for imaging ground target, applied to earth observation satellite, first, the strict regression orbit of each circle of earth observation satellite is fitted, the target function corresponding to the strict regression orbit of each circle is obtained, and the target function is used to describe the mapping relationship between the position information of any orbit point in the strict regression orbit and latitude depression angle;Then, based on the position information of the specified target observation point and the orbit parameters of the strict regression orbit of each circle, the virtual orbit passing through the target observation point is constructed, to determine the latitude depression angle sequence corresponding to the earth observation satellite running on each circle of virtual orbit and passing through the target observation point;Then, through the target function, the initial reference orbit point is determined from the strict regression orbit of each circle based on the latitude depression angle sequence, and the initial reference orbit point is compensated multiple times to obtain the target reference orbit point in the strict regression orbit of each circle, so that the vector formed by the target observation point and the target reference orbit point is perpendicular to the velocity vector of the earth observation satellite passing through the target reference orbit point;Finally, if the target reference orbit point in the strict regression orbit of each circle meets the preset observation constraint, the earth observation satellite executes the ground target imaging task for the target observation point when passing through the target reference orbit point.The above method fits the target function corresponding to the strict regression orbit of each circle of earth observation satellite and constructs the virtual orbit corresponding to the strict regression orbit of each circle, determines the initial reference orbit point, and then compensates multiple times to obtain the target reference orbit point that can be used for observing the target observation point, and finally executes the ground target imaging task when the target reference orbit point meets the preset observation constraint, so that the on-orbit autonomous task planning of the earth observation satellite is realized, and the dependence on ground station is eliminated, so that the autonomy of the earth observation satellite in on-orbit operation and the real-time performance of the ground target imaging task planning are improved.

[0035] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by the structure particularly pointed out in the description, claims and drawings.

[0036] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the description of specific embodiments or prior art. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0038] Figure 1 A flowchart of an on-orbit autonomous task planning method for imaging a ground target provided by an embodiment of the present application is shown in FIG. 1.

[0039] Figure 2 A flowchart of an on-orbit autonomous task planning method for imaging a ground target provided by an embodiment of the present application is shown in FIG. 1.

[0040] Figure 3 A schematic diagram of an initial reference orbit point P provided by an embodiment of the present application is shown in FIG. 2.

[0041] Figure 4 A schematic diagram of a spherical triangle solution intermediate reference orbit point R provided by an embodiment of the present application is shown in FIG. 3.

[0042] Figure 5 A schematic diagram of an iterative solution target reference orbit point Q provided by an embodiment of the present application is shown in FIG. 4.

[0043] Figure 6 An effect diagram of observing a target observation point at a target reference orbit point provided by an embodiment of the present application is shown in FIG. 5.

[0044] Figure 7 A structural schematic diagram of an on-orbit autonomous task planning device for imaging a ground target provided by an embodiment of the present application is shown in FIG. 6.

[0045] Figure 8 A structural schematic diagram of an electronic device provided by an embodiment of the present application is shown in FIG. 7. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of embodiments of the present application clearer, the technical solutions of the present application will be described below in connection with embodiments. Obviously, the described embodiments are only some, but not all, of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0047] Currently, the existing satellite ground target imaging task planning means has weak satellite autonomy and weak planning real-time, and based on this, the present application provides an on-orbit autonomous task planning method, device, and equipment for imaging a ground target, which can significantly improve the satellite autonomy and task planning real-time in the process of planning a ground target imaging task.

[0048] To facilitate understanding of the embodiments, first, a on-orbit autonomous task planning method for imaging a ground target disclosed by the embodiments of the present application is described in detail, referring to FIG. 1. Figure 1A flowchart of an on-orbit autonomous mission planning method for imaging a ground target is shown, which mainly includes the following steps S102 to S108:

[0049] Step S102, fitting each strict regression orbit of the earth observation satellite to obtain a target function corresponding to each strict regression orbit.

[0050] The target function is used to describe the mapping relationship between the position information of any orbit point in the strict regression orbit and the latitude depression angle, and through the target function, the corresponding position information can be found according to the latitude depression angle of the current point. In an example, the position information of each orbit point in each strict regression orbit in the earth-fixed coordinate system can be fitted as a function of the latitude depression angle according to the orbit revolution to obtain the target function corresponding to each strict regression orbit.

[0051] Step S104, based on the position information of the specified target observation point and the orbit parameters of each strict regression orbit, a virtual orbit passing through the target observation point is constructed to determine the corresponding latitude depression angle sequence of the earth observation satellite when running on each virtual orbit and passing through the target observation point.

[0052] In an example, the virtual orbit of the earth observation satellite passing through the target observation point can be constructed only by changing the ascending node right ascension of the strict regression orbit based on the orbit parameters of the strict regression orbit, and the revolution of the virtual orbit is consistent with that of the strict regression orbit, so that the latitude depression angle u aim .

[0053] Step S106, determining the initial reference orbit point from each strict regression orbit based on the latitude depression angle sequence through the target function, and compensating the initial reference orbit point multiple times to obtain the target reference orbit point in each strict regression orbit, so that the vector formed by the target observation point and the target reference orbit point is perpendicular to the velocity vector of the earth observation satellite when passing through the target reference orbit point.

[0054] First, according to the latitude depression angle sequence and the fitting coefficients of the target function, the initial reference orbit point P with the latitude depression angle u aim is found on the strict regression orbit;

[0055] Then, by using the geometric relationship of spherical triangle, the initial reference orbit point P in each strict regression orbit is compensated once to obtain the intermediate reference orbit point R in each strict regression orbit, so that the vector formed by the target observation point and the intermediate reference orbit point R is perpendicular to the running track of the intermediate reference orbit point R;

[0056] Finally, a second compensation is cycled for the intermediate reference orbit point R in each strict regression orbit. In an example, the intermediate reference orbit point R is taken as an initial value Q0 of the target reference orbit point Q, and the initial value Q0 is solved in the projection of the velocity in the inertial coordinate system in the ground coordinate system The projection That is, the aforementioned velocity vector, the target reference orbit point Q is iteratively optimized to make the vector formed by the target observation point and the reference orbit point Q perpendicular to .

[0057] In step S108, if the target reference orbit point in each strict regression orbit satisfies the preset observation constraint, the earth observation satellite performs the earth target imaging task for the target observation point when passing through the target reference orbit point.

[0058] The preset observation constraint includes a preset latitude and longitude constraint and a preset side view angle constraint. In an example, the target reference orbit point Q that can realize the observation of the earth observation target is determined by the side view angle constraint and the latitude and longitude constraint when observing the target observation point.

[0059] The on-orbit autonomous task planning method for earth target imaging provided by the embodiment of the present application determines the initial reference orbit point by fitting the target function corresponding to each strict regression orbit and constructing the virtual orbit corresponding to each strict regression orbit for the earth observation satellite, and obtains the target reference orbit point that can be used for observing the target observation point by performing multiple compensations on the initial reference orbit point. Finally, the earth target imaging task is executed when the target reference orbit point satisfies the preset observation constraint. The on-orbit autonomous task planning method for earth target imaging provided by the embodiment of the present application is performed by the earth observation satellite, and thus the dependence on the ground station is eliminated, and the autonomy of the earth observation satellite in on-orbit operation and the real-time performance of the earth target imaging task planning are improved.

[0060] The on-orbit autonomous task planning method for earth target imaging provided by the embodiment of the present application eliminates the dependence on the ground station and judges the visibility and observation parameters of the target observation point on the ground based on the strict regression orbit. The method includes: virtual orbit construction, calculation of the reference point (that is, the initial reference orbit point) for preliminary earth imaging, preliminary compensation of the reference point by using the spherical triangle, and iterative optimization to obtain the final reference point (that is, the target reference orbit point) for earth imaging. The embodiment of the present application provides a special calculation method, which can autonomously calculate the time and side view angle for earth imaging of the satellite in the strict regression orbit. The embodiment of the present application solves the problem of autonomously calculating the over-the-top time and side view angle for the given target observation point in the process of on-orbit autonomous task planning on the satellite, eliminates the dependence on the ground station, and improves the autonomy of the satellite in on-orbit operation.

[0061] For ease of understanding, a specific implementation of the on-orbit autonomous task planning method for earth target imaging is provided in the embodiment of the present application, which is described in detail with reference to the accompanying drawingsFigure 2 An overall flowchart of an on-board autonomous mission planning method for imaging a ground target is shown, including the following steps S202 to S212:

[0062] Step S202, strictly regression orbit fitting, the obtained polynomial coefficients are uploaded to the earth observation satellite. In an example, the strictly regression orbit is divided according to the orbit revolution, and the polynomial fitting is performed for each revolution of the strictly regression orbit, and the target function is fitted with the latitude amplitude angle as the independent variable.

[0063] The expression of the target function is as follows:

[0064] x fixedN =C Nnx ·u n +C Nn-1x ·u n-1 +…+C N2x u 2 +C N1x u+C N0x ;

[0065] y fixedN =C Nny ·u n +C Nn-1y ·u n-1 +…+C N2y u 2 +C N1y u+C N0y ;

[0066] z fixedN =C Nnz ·u n +C Nn-1z ·u n-1 +…+C N2z u 2 +C N1z u+C N0z ;

[0067] Where x fixed , y fixed , z fixed , a are the position information (x, y, z) and the semi-major axis of the strictly regression orbit in the earth-fixed coordinate system, respectively, C is the polynomial coefficient, u is the latitude amplitude angle, n is the fitting order, and N is the revolution.

[0068] Step S204, a virtual orbit is constructed, and the subsolar point of the virtual orbit passes through the target observation point. In one example, the orbit parameters of the strict regression orbit include semi-major axis, eccentricity, inclination, argument of perigee, and right ascension of the ascending node. For each orbit of the strict regression orbit, the semi-major axis, eccentricity, and argument of perigee of the strict regression orbit are kept unchanged, the right ascension of the ascending node of the strict regression orbit is changed, and a virtual orbit passing through the target observation point is constructed in combination with the position information of the target observation point.

[0069] For example, the longitude of the target point is Lon aim , the latitude of the target point is Lat aim , the inclination of the strict regression orbit is incl, and a virtual orbit whose subsolar point passes through the target observation point is designed on this basis. The semi-major axis, eccentricity, argument of perigee, and right ascension of the ascending node of the virtual orbit are consistent with those of the strict regression orbit. When the earth observation satellite runs on the virtual orbit and the subsolar point is the target point, the latitude amplitude of the earth observation satellite is as follows:

[0070] The latitude amplitude sequence is as follows:

[0071] Step S206, the initial reference orbit point P and its position information are calculated. In one example, for each orbit of the strict regression orbit, the latitude elevation angle sequence is input into the target function corresponding to the strict regression orbit, so that the target function outputs the position information of the initial reference orbit point for the latitude elevation angle sequence.

[0072] According to the polynomial coefficients fitted in step S202, the initial reference orbit points in N orbits of the strict regression orbit, i.e., N initial reference orbit points P, are calculated. The calculation formula of the initial reference orbit point P is as follows:

[0073]

[0074] i = 1, 2, …, N, i.e., the i-th orbit of the strict regression orbit or the i-th initial reference orbit point P.

[0075] is the polynomial fitting coefficient of the i-th orbit of the strict regression orbit on the X-axis of the earth-fixed coordinate system, is the polynomial fitting coefficient of the i-th orbit of the strict regression orbit on the Y-axis of the earth-fixed coordinate system, is the polynomial fitting coefficient of the i-th orbit of the strict regression orbit on the Z-axis of the earth-fixed coordinate system, i.e.,

[0076]

[0077] is the initial reference orbit point of the i-th orbit of the strict regression orbit, and P fixed (i) = [X fixed (i)Yfixed (i)Z fixed (i)], used to describe the initial reference orbit point P fixed (i) Position information in the Earth-fixed coordinate system, such as Figure 3 The diagram shows an initial reference orbit point P, which is also the strict regression orbit. Tar is the target observation point, and P is the reference orbit point. fixed (i) is the initial reference orbit point of the strict regression orbit of the i-th cycle.

[0078] Then the initial reference orbit point P fixed (i) The latitude and longitude information of the sub-satellite point is:

[0079]

[0080] Lon P(i) =atan2(Y fixed (i),X fixed (i)).

[0081] Step S208: The initial reference orbit point P is compensated using a spherical triangle to obtain the intermediate reference orbit point R. That is, the initial reference orbit point is compensated once based on the position information of the target observation point to obtain the intermediate reference orbit point in each strict regression orbit, so that the vector formed by the target observation point and the intermediate reference orbit point is perpendicular to the strict regression orbit to which the intermediate reference orbit point belongs.

[0082] The compensation process is as follows: First, using the spherical triangle algorithm, based on the position information of the target observation point and the orbital parameters of the strict regression orbit, the latitude depression angle corresponding to the initial reference orbit point after the first compensation is determined; then, the latitude depression angle after the first compensation is input into the objective function corresponding to the strict regression orbit, so that the objective function outputs the position information of the intermediate reference orbit point for the latitude depression angle after the first compensation.

[0083] For ease of understanding, see [link to relevant documentation]. Figure 4 The diagram shows a method for solving an intermediate reference orbit point R using a spherical triangle. The target observation point is denoted as A, and the i-th initial reference orbit point is P. fixed (i) Let B be the sub-satellite point and C be the i-th intermediate reference orbit point R(i). The following solution is performed using a spherical triangle:

[0084]

[0085] ΔLon(i)=Lon aim -Lon P(i) ;

[0086] α(i)=asin(sin(ΔLon(i))·sinA(i));

[0087] β(i) = asin(tan(a(i)) · cot A(i));

[0088] Wherein, A(i) is the angle of ∠BAC, ΔLon(i) is the angle corresponding to the arc length of AB, which can also be denoted as γ(i), a(i) is the angle corresponding to the arc length of BC, and β(i) is the angle corresponding to the arc length of AC, which can be used as the compensation of the latitude amplitude angle.

[0089] Then the latitude depression angle after the first compensation is u plus (i) = u aim + β(i);

[0090] Calculate the position information of the intermediate reference orbit point R:

[0091]

[0092] Wherein, is the latitude depression angle sequence after the first compensation;

[0093] Then, the position information of the i-th intermediate reference orbit point R(i) in the earth-fixed coordinate system is: R(i) = [XR fixed (i), YR fixed (i), ZR fixed (i)].

[0094] Step S210, the intermediate reference orbit point R is optimized by iteration to obtain the target reference orbit point Q. That is, the intermediate reference orbit point is offset to obtain an offset orbit point, the intermediate reference orbit point is compensated twice by using the offset orbit point, the position information of the new intermediate reference orbit point is obtained, and the new intermediate reference orbit point is continuously offset to obtain a new offset orbit point, until the preset loop termination condition is met, and the new intermediate reference orbit point obtained at the loop termination is taken as the target reference orbit point in the strict regression orbit.

[0095] The process of the second compensation is as follows, including (1) to (4):

[0096] (1) For each strict regression orbit, the intermediate reference orbit point is offset to obtain an offset orbit point, and the latitude depression angle of the offset orbit point is input into the target function corresponding to the strict regression orbit, so that the target function outputs the position information corresponding to the offset orbit point for the latitude depression angle of the offset orbit point.

[0097] Referring to Figure 5 Fig. 1 is a schematic diagram of an iterative solution of the target reference orbit point Q, wherein the intermediate reference orbit point is taken as the initial value of the target reference orbit point, and specifically:

[0098] Q0(i) = R(i);

[0099] u0(i) = u plus (i);

[0100]

[0101] wherein Q0(i) is initial position information of the i-th target reference orbit point Q, u0(i) is initial latitude elevation angle of the i-th target reference orbit point Q, ui(i) is latitude elevation angle of the offset orbit point obtained after offsetting the i-th target reference orbit point Q by 0.001°, and ΔT is time corresponding to change of 0.001° in latitude amplitude angle from Q0 to Q1. wherein a is semi-major axis of the strict return orbit, and μ is earth gravity constant.

[0102] Calculate position information of the offset orbit point Q1 corresponding to the latitude elevation angle ui(i):

[0103]

[0104]

[0105] wherein, is latitude elevation angle sequence of the offset orbit point;

[0106] Then, position information of the offset orbit point Q1 in the earth-fixed coordinate system is: Q1(i) = [XQ1 fixed (i), YQ1 fixed (i), ZQ1 fixed (i)].

[0107] (2) Based on the position information corresponding to the offset orbit point, determine the velocity vector of the earth observation satellite when passing through the intermediate reference orbit point in the earth-fixed coordinate system.

[0108] In an example, calculate the velocity V fixed (i) of Q0 in the earth-fixed coordinate system:

[0109]

[0110] The Coriolis velocity is V e (i) = [0, 0, n earth ] × Q0(i); wherein n earth is earth rotation angular velocity.

[0111] Then, the projection of the velocity of the inertial coordinate system at Q0 in the earth-fixed coordinate system is:

[0112]

[0113] ​(3) Based on the velocity vector, the projection of the vector formed by the intermediate reference orbit point and the offset orbit point in the velocity direction is determined to determine the secondary compensation latitude depression angle.

[0114] In an example, the vector of Q0 to the target observation point is: wherein R aim is the position of the target observation point in the earth-fixed coordinate system, R ain = [R earth · cos Lat aim · cos Lon ain , R earth · cos Lat aim · sin Lon ain , R earth · sin Lat aim ]; and R earth is the radius of the earth.

[0115] The projection in the velocity direction is calculated as: The compensation amount of the latitude amplitude angle is calculated as:

[0116] The latitude depression angle of Q0 is updated using the compensation amount u del of the latitude amplitude angle, and the compensated latitude depression angle is the secondary compensation latitude depression angle u0(i): u0(i) = u0(i) + u del .

[0117] (4) The secondary compensation latitude depression angle is input into the target function corresponding to the strict regression orbit, so that the target function outputs the position information of the new intermediate reference orbit point with respect to the secondary compensation latitude depression angle.

[0118] In an example, the secondary compensation latitude depression angle u0(i) is input into the target function to update Q0(i):

[0119]

[0120] wherein,

[0121] is the secondary compensation latitude depression angle sequence; The position information of the new intermediate reference orbit point Q0(i) in the earth-fixed coordinate system is: fixed Q0(i) = [XQ0 fixed (i), YQ0 fixed (i), ZQ0 end (i)].

[0122] Optionally, the steps (1) to (4) are repeated until a preset number of times (such as ten times) is reached, and then Q0(i) is the position of the target observation point.end (i) = Q0(i), Q end (i) is the i-th target reference orbit point.

[0124] Step S220, according to the threshold, the target reference orbit point Q that can observe the target observation point is selected. That is, the side-looking angle of the earth observation satellite when imaging the target observation point at the target reference orbit point Q end (i) is calculated. According to the latitude and longitude threshold and the side-looking angle threshold, the position that can be observed is extracted. Specifically, it includes the following (I) to (II):

[0125] (I) Determine the latitude and longitude information and the side-looking angle information of the target reference orbit point in each strictly recurrent orbit.

[0126] The subspace point latitude and longitude information [Lat Q (i), Lon Q (i)] is calculated according to the following formula:

[0127]

[0128] Lon Q (i) = atan2 (YQ0 fixed (i), XQ0 fixed (i));

[0129] The side-looking angle size ang cs (i) is calculated according to the following formula:

[0130]

[0131]

[0132] Wherein, is the vector from Q0(i) to the target observation point.

[0133] Tmp2 is calculated according to the following formula:

[0134]

[0135] Wherein, is an intermediate parameter, which has no actual meaning. In an example, if: Tmp2>0, it is right side view, otherwise it is left side view.

[0136] (II) If the latitude and longitude information of the target reference orbit point meets the preset latitude and longitude constraint, and the side-looking angle information of the target reference orbit point meets the preset side-looking angle constraint, it is determined that the earth observation satellite can observe the target observation point when passing through the target reference orbit point, and the earth target imaging task is executed for the target observation point according to the latitude and longitude information and the side-looking angle information.

[0137] In practical applications, if the latitude and longitude information [Lat Q (i), Lon Q (i)] of the target observation point deviates from the latitude and longitude information of the target observation point within a threshold range, and the side view angle size ang cs (i) is within a side view angle threshold range, the target observation point can be observed at Q end (i), such as Figure 6 An effect diagram of observing a target observation point at a target reference orbit point.

[0138] In summary, the embodiment of the application solves the problem of autonomous planning of on-orbit target imaging, ensures the real-time performance of the on-orbit satellite, improves the autonomy and redundancy of the satellite, avoids the problem of poor accuracy of on-orbit orbit recursion, and calculates the parameters of the target imaging on the ground using the nominal reference orbit.

[0139] On the basis of the foregoing embodiment, the embodiment of the application provides an on-orbit autonomous task planning device for target imaging on the ground, referring to Figure 7 An on-orbit autonomous task planning device for target imaging on the ground, as shown in a structural schematic diagram of the device, mainly includes the following parts:

[0140] The function fitting module 702 is configured to fit each strict regression orbit of the earth observation satellite to obtain a target function corresponding to each strict regression orbit, the target function being configured to describe the mapping relationship between the position information of any orbit point in the strict regression orbit and the latitude depression angle.

[0141] The virtual orbit construction module 704 is configured to construct a virtual orbit passing through the target observation point based on the position information of the target observation point and the orbit parameters of each strict regression orbit, and determine the corresponding latitude depression angle sequence of the earth observation satellite when running on each virtual orbit and passing through the target observation point.

[0142] The reference point determination module 706 is configured to determine an initial reference orbit point from each strict regression orbit based on the latitude depression angle sequence through the target function, and compensate the initial reference orbit point multiple times to obtain a target reference orbit point in each strict regression orbit, so that the vector formed by the target observation point and the target reference orbit point is perpendicular to the velocity vector of the earth observation satellite when passing through the target reference orbit point.

[0143] The task planning module 708 is configured to execute the target imaging task on the target observation point when the earth observation satellite passes through the target reference orbit point if the target reference orbit point in each strict regression orbit meets the preset observation constraint.

[0144] The on-orbit autonomous task planning method for imaging the target on the earth provided by the embodiment of the application comprises the following steps: fitting a target function corresponding to a strict regression orbit of each orbit of an earth observation satellite and constructing a virtual orbit corresponding to the strict regression orbit of each orbit, determining an initial reference orbit point, performing compensation on the initial reference orbit point multiple times to obtain a target reference orbit point which can be used for observing a target observation point, and finally executing a task of imaging the target on the earth under the condition that the target reference orbit point meets a preset observation constraint. The on-orbit autonomous task planning method for imaging the target on the earth provided by the embodiment of the application is performed by the earth observation satellite, and thus the dependence on the ground station is eliminated, and the autonomy of the earth observation satellite in on-orbit operation and the real-time performance of the task planning for imaging the target on the earth are improved.

[0145] In an embodiment, the orbit parameters of the strict regression orbit comprise a semi-major axis, an eccentricity, an inclination, an argument of perigee, and a longitude of ascending node; and the virtual orbit construction module 704 is specifically configured to:

[0146] For the strict regression orbit of each orbit, the semi-major axis, the eccentricity, and the argument of perigee of the strict regression orbit are kept unchanged, the longitude of ascending node of the strict regression orbit is changed, and a virtual orbit passing through the target observation point is constructed in combination with the position information of the specified target observation point.

[0147] In an embodiment, the reference point determination module 706 is specifically configured to:

[0148] For the strict regression orbit of each orbit, the latitude and the pitch angle sequence are input to the target function corresponding to the strict regression orbit, so that the target function outputs the position information of the initial reference orbit point for the latitude and the pitch angle sequence.

[0149] In an embodiment, the reference point determination module 706 is specifically configured to:

[0150] The initial reference orbit point is compensated once based on the position information of the target observation point to obtain an intermediate reference orbit point in the strict regression orbit of each orbit, so that the vector formed by the target observation point and the intermediate reference orbit point is perpendicular to the strict regression orbit to which the intermediate reference orbit point belongs;

[0151] The intermediate reference orbit point is subjected to offset processing to obtain an offset orbit point, the intermediate reference orbit point is compensated twice by using the offset orbit point to obtain the position information of a new intermediate reference orbit point, and the new intermediate reference orbit point is subjected to offset processing to obtain a new offset orbit point, until a preset loop termination condition is met, and the new intermediate reference orbit point obtained at the loop termination is taken as the target reference orbit point in the strict regression orbit.

[0152] In an embodiment, the reference point determination module 706 is specifically configured to:

[0153] Compensate the initial reference orbit point based on the position information of the target observation point to obtain an intermediate reference orbit point in a strict regression orbit of each orbit, including:

[0154] For each strict regression orbit, determine a once-compensated latitude and elevation angle corresponding to the initial reference orbit point based on the position information of the target observation point and the orbit parameters of the strict regression orbit by using a spherical triangle algorithm.

[0155] Input the once-compensated latitude and elevation angle into the target function corresponding to the strict regression orbit, so that the target function outputs the position information of the intermediate reference orbit point for the once-compensated latitude and elevation angle.

[0156] In an implementation, the reference point determination module 706 is specifically configured to:

[0157] For each strict regression orbit, perform offset processing on the intermediate reference orbit point to obtain an offset orbit point, input the latitude and elevation angle of the offset orbit point into the target function corresponding to the strict regression orbit, so that the target function outputs the position information corresponding to the offset orbit point for the latitude and elevation angle of the offset orbit point.

[0158] Determine the velocity vector of the earth observation satellite in the earth-fixed coordinate system when passing through the intermediate reference orbit point based on the position information corresponding to the offset orbit point.

[0159] Determine the projection of the vector formed by the intermediate reference orbit point and the offset orbit point in the velocity direction based on the velocity vector, to determine a twice-compensated latitude and elevation angle, and input the twice-compensated latitude and elevation angle into the target function corresponding to the strict regression orbit, so that the target function outputs the position information of a new intermediate reference orbit point for the twice-compensated latitude and elevation angle.

[0160] In an implementation, the preset observation constraints include preset longitude and latitude constraints and preset side-view angle constraints; the task planning module 708 is specifically configured to:

[0161] Determine the longitude and latitude information and the side-view angle information of the target reference orbit point in each strict regression orbit.

[0162] If the longitude and latitude information of the target reference orbit point satisfies the preset longitude and latitude constraints, and the side-view angle information of the target reference orbit point satisfies the preset side-view angle constraints, it is determined that the target observation point can be observed by the earth observation satellite when passing through the target reference orbit point, and the earth target imaging task is performed on the target observation point according to the longitude and latitude information and the side-view angle information.

[0163] The device provided in the embodiments of the present application has the same implementation principle and technical effects as the foregoing method embodiments. For brevity, the part not mentioned in the device embodiment part can be referred to the corresponding content in the foregoing method embodiments.

[0164] The electronic device provided by the embodiments of the present application specifically comprises a processor and a storage device; the storage device stores a computer program, and the computer program performs the method according to any one of the embodiments when executed by the processor.

[0165] Figure 8 The electronic device 100 provided by the embodiments of the present application comprises a processor 80, a memory 81, a bus 82 and a communication interface 83, the processor 80, the communication interface 83 and the memory 81 are connected through the bus 82; the processor 80 is used to execute the executable modules stored in the memory 81, such as a computer program.

[0166] The memory 81 can contain a high-speed random access memory (RAM) and can also include a non-volatile memory, such as at least one disk memory. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 83 (which can be wired or wireless), and the Internet, a wide area network, a local area network, a metropolitan area network, etc. can be used.

[0167] The bus 82 can be an ISA bus, a PCI bus or an EISA bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, Figure 8 Only one bidirectional arrow is used in the figure, but it does not mean that there is only one bus or only one type of bus.

[0168] The memory 81 is used to store a program, and the processor 80 executes the program after receiving an execution instruction. The method performed by the device defined by the flow process disclosed in any one of the embodiments of the present application can be applied to the processor 80 or realized by the processor 80.

[0169] The processor 80 can be an integrated circuit chip with signal processing capability. In implementation, each step of the above method can be completed by integrated logic circuit of hardware in the processor 80 or by instructions in the form of software. The processor 80 described above can be a general processor, including a central processing unit (CPU), a network processor (NP), etc.; can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. Each method, step and logic block diagram disclosed in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium in the art. The storage medium is located in the memory 81, and the processor 80 reads the information in the memory 81, and combines the hardware to complete the steps of the above method.

[0170] The computer program product of the readable storage medium provided by the embodiments of the present application comprises a computer readable storage medium storing program codes, and the program codes comprise instructions for executing the method described in the foregoing method embodiments. For specific implementation, reference can be made to the foregoing method embodiments, which will not be described here.

[0171] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the present application that essentially contribute to the prior art or the parts of the technical solutions can be embodied in the form of software products. The computer software product is stored in a storage medium and includes instructions for making a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0172] Finally, it should be noted that: the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, but not to limit them. The protection scope of the present application is not limited to this. Although the present application has been 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 think of changes to the technical solutions recorded in the foregoing embodiments within the technical range disclosed by the present application, or make equivalent replacements to some technical features. The modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A satellite-based autonomous mission planning method for imaging Earth targets, characterized in that, The method is applied to Earth observation satellites, including: The Earth observation satellite's strict regression orbit is fitted to obtain the objective function corresponding to each strict regression orbit. The objective function is used to describe the mapping relationship between the position information of any orbital point in the strict regression orbit and the latitude depression angle. Based on the location information of the specified target observation point and the orbit parameters of the strict regression orbit for each orbit, a virtual orbit passing through the target observation point is constructed to determine the latitude depression angle sequence corresponding to the Earth observation satellite running on the virtual orbit for each orbit and passing through the target observation point; Using the objective function, an initial reference orbit point is determined from each of the strictly regressed orbits based on the latitude depression angle sequence, and the initial reference orbit point is compensated multiple times to obtain the target reference orbit point in each of the strictly regressed orbits, so that the vector formed by the target observation point and the target reference orbit point is perpendicular to the velocity vector of the Earth observation satellite when it passes the target reference orbit point; If the target reference orbit point in each of the strictly regressed orbits satisfies the preset observation constraints, then when the Earth observation satellite passes the target reference orbit point, it performs an Earth target imaging task for the target observation point.

2. The on-board autonomous mission planning method for imaging Earth targets according to claim 1, characterized in that, The orbital parameters of the strictly regressed orbit include the semi-major axis, eccentricity inclination, perigee argument, and right ascension of the ascending node; Based on the location information of the specified target observation point and the orbital parameters of the strict regression orbit for each lap, a virtual orbit passing through the target observation point is constructed, including: For each lap of the strictly regressed orbit, the semi-major axis, the eccentricity inclination, and the perigee argument of the strictly regressed orbit are kept constant. The right ascension of the ascending node of the strictly regressed orbit is changed, and a virtual orbit passing through the target observation point is constructed by combining the position information of the specified target observation point.

3. The on-board autonomous mission planning method for imaging Earth targets according to claim 1, characterized in that, Using the objective function, the initial reference orbit points are determined from each of the strictly regressed orbits based on the latitude depression angle sequence, including: For each lap of the strictly regressed orbit, the latitude depression sequence is input into the objective function corresponding to the strictly regressed orbit, so that the objective function outputs the position information of the initial reference orbit point for the latitude depression sequence.

4. The on-board autonomous mission planning method for imaging Earth targets according to claim 1, characterized in that, The initial reference orbit point is compensated multiple times to obtain the target reference orbit point in each lap of the strict regression orbit: Based on the location information of the target observation point, the initial reference orbit point is compensated once to obtain the intermediate reference orbit point in each cycle of the strict regression orbit, so that the vector formed by the target observation point and the intermediate reference orbit point is perpendicular to the strict regression orbit to which the intermediate reference orbit point belongs. The intermediate reference orbit point is offset to obtain an offset orbit point. The offset orbit point is then used to perform secondary compensation on the intermediate reference orbit point to obtain the position information of the new intermediate reference orbit point. The offset process is then continued to be performed on the new intermediate reference orbit point to obtain a new offset orbit point, until a preset cycle cutoff condition is met. The new intermediate reference orbit point obtained at the end of the cycle is taken as the target reference orbit point in the strict regression orbit.

5. The on-board autonomous mission planning method for imaging Earth targets according to claim 4, characterized in that, Based on the location information of the target observation point, the initial reference orbit point is compensated once to obtain the intermediate reference orbit point in each cycle of the strict regression orbit, including: Based on the location information of the target observation point, the initial reference orbit point is compensated once to obtain the intermediate reference orbit point in each cycle of the strict regression orbit, including: For each lap of the strictly regressed orbit, the spherical triangle algorithm is used to determine the first-compensated latitude depression angle corresponding to the initial reference orbit point based on the position information of the target observation point and the orbit parameters of the strictly regressed orbit. The first-compensated latitude depression angle is input into the objective function corresponding to the strict regression orbit, so that the objective function outputs the position information of the intermediate reference orbit point for the first-compensated latitude depression angle.

6. The on-board autonomous mission planning method for imaging Earth targets according to claim 4, characterized in that, The intermediate reference orbit point is offset to obtain an offset orbit point. The offset orbit point is then used to perform secondary compensation on the intermediate reference orbit point to obtain new position information for the intermediate reference orbit point, including: For each lap of the strict regression orbit, the intermediate reference orbit point is offset to obtain the offset orbit point. The latitude and depression angle of the offset orbit point are input into the objective function corresponding to the strict regression orbit, so that the objective function outputs the position information corresponding to the offset orbit point based on the latitude and depression angle of the offset orbit point. Based on the position information corresponding to the offset orbit point, determine the velocity vector of the Earth observation satellite in the Earth-fixed coordinate system when it passes the intermediate reference orbit point; Based on the velocity vector, the projection of the vector formed by the intermediate reference orbit point and the offset orbit point in the velocity direction is determined, which is used to determine the secondary compensation latitude depression angle. The secondary compensation latitude depression angle is input into the objective function corresponding to the strict regression orbit, so that the objective function outputs the new position information of the intermediate reference orbit point for the secondary compensation latitude depression angle.

7. The on-board autonomous mission planning method for imaging Earth targets according to claim 1, characterized in that, The preset observation constraints include preset latitude and longitude constraints and preset side-view constraints; if the target reference orbit point in each of the strictly regressed orbits satisfies the preset observation constraints, then when the Earth observation satellite passes the target reference orbit point, it performs an Earth target imaging task for the target observation point, including: Determine the latitude, longitude, and side view information of the target reference orbit point in each of the strictly regressed orbits; If the latitude and longitude information of the target reference orbit point meets the preset latitude and longitude constraints, and the side view information of the target reference orbit point meets the preset side view constraints, then it is determined that the Earth observation satellite can observe the target observation point when passing the target reference orbit point, and performs an Earth target imaging task for the target observation point according to the latitude and longitude information and the side view information.

8. An onboard autonomous mission planning device for imaging Earth targets, characterized in that, The device is applied to Earth observation satellites and includes: The function fitting module is used to fit each strict regression orbit of the Earth observation satellite to obtain the objective function corresponding to each strict regression orbit. The objective function is used to describe the mapping relationship between the position information of any orbit point in the strict regression orbit and the latitude depression angle. The virtual orbit construction module is used to construct a virtual orbit passing through the target observation point based on the location information of the specified target observation point and the orbit parameters of the strict regression orbit for each orbit, so as to determine the latitude depression angle sequence corresponding to the Earth observation satellite running on the virtual orbit for each orbit and passing through the target observation point; The reference point determination module is used to determine an initial reference orbit point from each of the strictly regressed orbits based on the latitude depression angle sequence using the objective function, and to perform multiple compensations on the initial reference orbit point to obtain a target reference orbit point in each of the strictly regressed orbits, so that the vector formed by the target observation point and the target reference orbit point is perpendicular to the velocity vector of the Earth observation satellite when it passes the target reference orbit point; The mission planning module is used to perform an Earth target imaging mission on the target observation point when the Earth observation satellite passes the target reference orbit point if the target reference orbit point in each orbit of the strict regression orbit meets the preset observation constraints.

9. An electronic device, characterized in that, The method includes a processor and a memory, the memory storing computer-executable instructions executable by the processor, the processor executing the computer-executable instructions to implement the method of any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions that, when invoked and executed by a processor, cause the processor to perform the method according to any one of claims 1 to 7.

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