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

Abstract

The invention provides an on-satellite autonomous task planning method, device and equipment for earth target imaging, and relates to the technical field of spaceflight, and the method comprises the steps: carrying out the fitting of each circle of strict regression orbit of an earth observation satellite, and obtaining a target function corresponding to each circle of strict regression orbit; constructing a 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 circle of strict regression orbit so as to determine a corresponding latitude depression angle sequence when the earth observation satellite runs on each circle of virtual orbit and passes through the target observation point; determining an initial reference orbit point based on the latitude depression angle sequence through the target function, and performing multiple times of compensation on the initial reference orbit point to obtain a target reference orbit point; and if the target reference orbit point satisfies the preset observation constraint, executing a ground target imaging task. According to the method, the satellite autonomy and the task planning real-time performance in the process of planning the earth target imaging task can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and in particular to an on-board autonomous mission planning method, device and equipment for imaging ground targets. Background Art

[0002] At present, satellite imaging missions for earth targets are generally planned through ground stations. Specifically, the ground stations plan the location information and time information of the target observation points based on the target observation points, and upload the above planning results to the satellite, which leads to weak autonomy and real-time planning of satellite imaging missions for earth targets. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide an onboard autonomous mission planning method, device and equipment for ground target imaging, which can significantly improve the satellite autonomy and real-time performance of mission planning in the process of planning ground target imaging missions.

[0004] In a first aspect, an embodiment of the present invention provides an onboard autonomous mission planning method for imaging a ground target, the method being applied to a ground observation satellite, comprising:

[0005] Fit each strictly regressive orbit of the earth observation satellite to obtain the objective function corresponding to each strictly regressive orbit. The objective function is used to describe the mapping relationship between the position information of any orbital point in the strictly regressive orbit and the latitude depression angle;

[0006] Based on the position information of the specified target observation point and the orbital 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 when the earth observation satellite runs on each virtual orbit and passes through the target observation point;

[0007] Through the objective function, the initial reference orbit point is determined from each strict regression orbit 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 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 it passes through the target reference orbit point;

[0008] If the target reference orbit point in each strict regression orbit meets the preset observation constraints, the earth observation satellite performs the earth target imaging task for the target observation point when passing through the target reference orbit point.

[0009] In one implementation, the orbital parameters of the strict regression orbit include the semi-major axis, the eccentricity inclination, the argument of perigee, and the right ascension of the ascending node; based on the position information of the specified target observation point and the orbital parameters of each strict regression orbit, constructing a virtual orbit passing through the target observation point includes:

[0010] For each strictly regressive orbit, the semi-major axis, eccentricity inclination and perigee argument of the strictly regressive orbit are kept unchanged, the right ascension of the ascending node of the strictly regressive orbit is changed, and the position information of the specified target observation point is combined to construct a virtual orbit passing through the target observation point.

[0011] In one embodiment, the initial reference orbit point is determined from each strictly regressive orbit based on the latitude depression angle sequence through the objective function, including:

[0012] For each strictly regressive orbit, the latitude depression angle sequence is input into the objective function corresponding to the strictly regressive orbit, so that the objective function outputs the position information of the initial reference orbit point for the latitude depression angle sequence.

[0013] In one implementation, the initial reference track point is compensated multiple times to obtain the target reference track point in each strict regression track:

[0014] Based on the position information of the target observation point, the initial reference orbit point is compensated once 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;

[0015] The intermediate reference orbit point is offset to obtain an offset orbit point, and the offset orbit point is used to perform secondary compensation on the intermediate reference orbit point to obtain the position information of a new intermediate reference orbit point, and the new intermediate reference orbit point is continuously offset to obtain a new offset orbit point until a preset loop cutoff condition is met, and the new intermediate reference orbit point obtained at the loop cutoff is used as the target reference orbit point in the strict regression orbit.

[0016] In one implementation, 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, including:

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

[0018] For each strictly regressive 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 orbital parameters of the strictly regressive orbit;

[0019] 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.

[0020] In one implementation, performing an offset process on the intermediate reference track point to obtain an offset track point, and performing secondary compensation on the intermediate reference track point using the offset track point to obtain position information of a new intermediate reference track point, including:

[0021] For each strictly regressive 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 objective function corresponding to the strictly regressive orbit, so that the objective function outputs the position information corresponding to the offset orbit point according to the latitude depression angle of the offset orbit point;

[0022] 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 through the intermediate reference orbit point;

[0023] Based on the velocity vector, determine the projection of the vector formed by the intermediate reference orbit point and the offset orbit point in the velocity direction to determine the quadratic compensation latitude depression angle, and input the quadratic compensation latitude depression angle into the objective function corresponding to the strict regression orbit so that the objective function outputs the position information of the new intermediate reference orbit point for the quadratic compensation latitude depression angle.

[0024] In one implementation, the preset observation constraints include preset latitude and longitude constraints and preset side view constraints; if the target reference orbit point in each strict regression orbit satisfies the preset observation constraints, then when the earth observation satellite passes through the target reference orbit point, performing an earth target imaging task for the target observation point includes:

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

[0026] If the longitude and latitude information of the target reference orbit point meets the preset longitude and latitude constraints, and the side viewing angle information of the target reference orbit point meets the preset side viewing angle constraints, it is determined that the earth observation satellite can observe the target observation point when passing through the target reference orbit point, and perform the earth target imaging task for the target observation point according to the longitude and latitude information and the side viewing angle information.

[0027] In a second aspect, an embodiment of the present invention further provides an onboard autonomous mission planning device for imaging a ground target, the device being applied to a ground observation satellite, comprising:

[0028] The function fitting module is used to fit each strictly regressive orbit of the earth observation satellite to obtain the target function corresponding to each strictly regressive orbit. The target function is used to describe the mapping relationship between the position information of any orbital point in the strictly regressive orbit and the latitude depression angle;

[0029] A virtual orbit construction module is used to construct a 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, so as to determine the corresponding latitude depression angle sequence when the earth observation satellite runs on each virtual orbit and passes through the target observation point;

[0030] A reference point determination module is used to determine the initial reference orbit point from each strict regression orbit based on the latitude depression angle sequence through the objective function, and to perform multiple compensations on the initial reference orbit point 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 it passes through the target reference orbit point;

[0031] The mission planning module is used to execute the earth target imaging mission for 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.

[0032] In a third aspect, an embodiment of the present invention further provides an electronic device, comprising a processor and a memory, wherein the memory stores computer-executable instructions that can be executed by the processor, and the processor executes the computer-executable instructions to implement any one of the methods provided in the first aspect.

[0033] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement any one of the methods provided in the first aspect.

[0034] An onboard autonomous mission planning method, device and equipment for imaging a ground target provided by an embodiment of the present invention are applied to a ground observation satellite. First, each strict regression orbit of the ground observation satellite is fitted to obtain a target function corresponding to each strict regression orbit, 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 the latitude depression angle; then, based on the position information of the specified target observation point and the orbital parameters of each strict regression orbit, a virtual orbit passing through the target observation point is constructed to determine the latitude depression angle sequence corresponding to the ground observation satellite running on each virtual orbit and passing through the target observation point; then, through the target function, an initial reference orbit point is determined from each strict regression orbit based on the latitude depression angle sequence, and the initial reference orbit point is compensated 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 ground observation satellite when passing through the target reference orbit point; finally, if the target reference orbit point in each strict regression orbit satisfies the preset observation constraint, the ground observation satellite performs the ground target imaging mission for the target observation point when passing through the target reference orbit point. The above method determines the initial reference orbit point by fitting the objective function corresponding to each strict regression orbit of the earth observation satellite and constructing the virtual orbit corresponding to each strict regression orbit, and then performs multiple compensations on it to obtain the target reference orbit point that can be used to observe the target observation point, and finally executes the earth target imaging task when the target reference orbit point meets the preset observation constraints. In the embodiment of the present invention, the earth observation satellite performs autonomous on-board task planning, gets rid of the dependence on ground stations, improves the autonomy of the earth observation satellite in orbit and the real-time performance of the earth target imaging task planning.

[0035] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic flow chart of an onboard autonomous mission planning method for imaging ground targets provided by an embodiment of the present invention;

[0039] Figure 2 A schematic diagram of the overall process of an onboard autonomous mission planning method for imaging ground targets provided by an embodiment of the present invention;

[0040] Figure 3 A schematic diagram of an initial reference orbit point P provided by an embodiment of the present invention;

[0041] Figure 4 A schematic diagram of a spherical triangle solution for an intermediate reference orbit point R provided by an embodiment of the present invention;

[0042] Figure 5 A schematic diagram of an iterative solution to a target reference orbit point Q provided by an embodiment of the present invention;

[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 invention;

[0044] Figure 7 A schematic diagram of the structure of an onboard autonomous mission planning device for imaging ground targets provided by an embodiment of the present invention;

[0045] Figure 8 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described in combination with the embodiments below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] At present, the existing planning methods for satellite imaging missions of ground targets have the problems of weak satellite autonomy and weak planning real-time performance. Based on this, the present invention provides an on-board autonomous mission planning method, device and equipment for ground target imaging, which can significantly improve the satellite autonomy and mission planning real-time performance in the process of planning ground target imaging missions.

[0048] To facilitate understanding of this embodiment, firstly, a satellite autonomous mission planning method for imaging a ground target disclosed in an embodiment of the present invention is described in detail. Figure 1The flowchart of a method for autonomous onboard mission planning for imaging a ground target is shown in FIG. 1 , and the method mainly includes the following steps S102 to S108:

[0049] Step S102, fitting each strictly regressive orbit of the earth observation satellite to obtain the objective function corresponding to each strictly regressive orbit.

[0050] Among them, 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. Through this objective function, the corresponding position information can be found according to the latitude depression angle of the current point. In one example, according to the orbital circles, the position information of each orbital point in each strict regression orbit in the earth-fixed coordinate system can be fitted with a function with the latitude depression angle as the independent variable to obtain the objective function corresponding to each strict regression orbit.

[0051] Step S104, based on the position information of the specified target observation point and the orbital 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 when the earth observation satellite runs on each virtual orbit and passes through the target observation point.

[0052] In one example, based on the orbital parameters of the strict regression orbit, only the right ascension of the ascending node can be changed to design a virtual orbit of the earth observation satellite passing through the target observation point. The number of circles of the virtual orbit is consistent with the number of circles of the strict regression orbit, so that the latitude depression angle u of the earth observation satellite when it is in the virtual orbit and passes through the target observation point can be obtained according to the position information of the target observation point (such as longitude and latitude information). aim .

[0053] Step S106, through the objective function, the initial reference orbit point is determined from each circle of strict regression orbit 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 circle of 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 coefficient of the objective function, the latitude depression angle u is found on the strict regression orbit. aim The initial reference orbit point P;

[0055] Then, using the geometric relationship of the 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 target observation point and the intermediate reference orbit point R form a running trajectory with a vector perpendicular to the intermediate reference orbit point R;

[0056] Finally, the intermediate reference orbit point R in each strict regression orbit is compensated cyclically. In one example, the intermediate reference orbit point R is used as the initial value Q0 of the target reference orbit point Q, and the projection of the velocity of the initial value Q0 in the inertial coordinate system in the earth-fixed coordinate system is solved. The projection That is, the aforementioned velocity vector is used, and the target reference orbit point Q is obtained by iterative optimization, so that the vector formed by the target observation point and the reference orbit point Q is equal to vertical.

[0057] 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 constraints include preset longitude and latitude constraints and preset side view constraints. In one example, the side view constraints and longitude and latitude constraints when observing the target observation point determine the target reference orbit point Q that can achieve the earth observation target.

[0059] The on-board autonomous mission planning method for imaging earth targets provided by the embodiment of the present invention determines the initial reference orbit point by fitting the objective function corresponding to each strict regression orbit of the earth observation satellite and constructing the virtual orbit corresponding to each strict regression orbit, and then performs multiple compensations on it to obtain the target reference orbit point that can be used to observe the target observation point, and finally executes the earth target imaging task when the target reference orbit point meets the preset observation constraints. The embodiment of the present invention performs on-board autonomous mission planning by the earth observation satellite, gets rid of the dependence on ground stations, improves the autonomy of the earth observation satellite in orbit and the real-time performance of the earth target imaging mission planning.

[0060] The embodiment of the present invention provides an on-board autonomous mission planning method for imaging ground targets, which gets rid of the dependence on ground stations and performs on-orbit judgment of visibility and observation parameters of target observation points on the ground based on a strict regression orbit. It includes: virtual orbit construction, calculation of preliminary reference points for ground imaging (i.e., initial reference orbit points), preliminary compensation of reference points using spherical triangles, and iterative optimization to obtain the final reference points for ground imaging (i.e., target reference orbit points). The embodiment of the present invention provides a set of special calculation methods that can autonomously calculate the moment and side viewing angle of ground imaging for satellites in strict regression orbits. The embodiment of the present invention solves the problem of autonomously calculating the time of passing and the side viewing angle for a given target observation point during the autonomous mission planning process on the satellite, gets rid of the dependence on ground stations, and improves the autonomy of the satellite's on-orbit operation.

[0061] For ease of understanding, the present invention provides a specific implementation of a satellite autonomous mission planning method for imaging a ground target, see Figure 2 The overall flow diagram of an onboard autonomous mission planning method for imaging a ground target shown includes the following steps S202 to S212:

[0062] Step S202, strict regression orbit fitting, injecting the fitted polynomial coefficients into the earth observation satellite. In one example, the strict regression orbit is divided according to the orbit circle, and a polynomial fitting is performed on each circle of the strict regression orbit to fit the objective function with the latitude argument as the independent variable.

[0063] The expression of the objective 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 semi-major axis of the strict regression orbit in the earth-fixed coordinate system, C is the polynomial coefficient, u is the latitude argument, n is the fitting order, and N is the number of cycles.

[0068] Step S204, constructing a virtual orbit so that its sub-satellite point passes through the target observation point. The orbital parameters of the strict regression orbit include the semi-major axis, eccentricity inclination, perigee argument, and ascending node right ascension. In one example, for each strict regression orbit, the semi-major axis, eccentricity inclination, and perigee argument of the strict regression orbit are kept unchanged, the ascending node right ascension of the strict regression orbit is changed, and the virtual orbit passing through the target observation point is constructed in combination with the position information of the specified 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. On this basis, a virtual orbit is designed in which the sub-satellite point passes through the target observation point. The semi-major axis, eccentricity inclination, and perigee argument of the virtual orbit are consistent with those of the strict regression orbit. When the earth observation satellite is running on the virtual orbit and the sub-satellite point is the target point, the latitude argument of the earth observation satellite is:

[0070] The latitude argument sequence is as follows:

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

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

[0073]

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

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

[0076]

[0077] The initial reference orbit point of the i-th strict regression orbit is denoted as 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 A schematic diagram of an initial reference orbit point P is shown in FIG. 1 , where the reference orbit is also a strict regression orbit, Tar is the target observation point, and P fixed (i) is the initial reference orbit point of the i-th strict regression orbit.

[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, using a spherical triangle to compensate the initial reference orbit point P to obtain an intermediate reference orbit point R. That is: based on the position information of the target observation point, the initial reference orbit point is compensated once 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 process of primary compensation is as follows: first, the spherical triangle algorithm is used to determine the latitude depression angle after primary compensation corresponding to the initial reference orbit point based on the position information of the target observation point and the orbital parameters of the strict regression orbit; then, the latitude depression angle after primary 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 primary compensation.

[0083] For easier understanding, see Figure 4 The schematic diagram of a spherical triangle solution for the intermediate reference orbit point R is shown in FIG. The target observation point is denoted as A, and the i-th initial reference orbit point P fixed (i) The subsatellite point is denoted as B, and the i-th intermediate reference orbit point R(i) is denoted as C. The spherical triangle is used to perform the following solution:

[0084]

[0085] ΔLon(i)=Lon aim -Lon P(i) ;

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

[0087] β(i)=asin(tan(α(i))·cotA(i));

[0088] Among them, A(i) is the angle of ∠BAC, ΔLon(i) is the angle corresponding to the arc length of AB, which can also be expressed as γ(i), α(i) is the angle corresponding to the arc length of BC, β(i) is the angle corresponding to the arc length of AC, and β(i) can be used as the compensation amount of latitude argument.

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

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

[0091]

[0092] in, is the latitude depression angle sequence after one 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 the offset orbit point, the offset orbit point is used to perform secondary compensation on the intermediate reference orbit point to obtain the position information of the new intermediate reference orbit point, and the new intermediate reference orbit point is continuously offset to obtain the new offset orbit point until the preset loop cutoff condition is met, and the new intermediate reference orbit point obtained at the loop cutoff is used as the target reference orbit point in the strict regression orbit.

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

[0096] (1) For each strict regression orbit, the intermediate reference orbit point is offset to obtain the offset orbit point, and the latitude depression angle of the offset orbit point is 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 according to the latitude depression angle of the offset orbit point.

[0097] See also Figure 5 FIG. 1 is a schematic diagram of an iterative solution to the target reference orbit point Q, wherein the intermediate reference orbit point is used as the initial value of the target reference orbit point. Specifically:

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

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

[0100]

[0101] Wherein, Q0(i) is the initial position information of the i-th target reference orbit point Q, u0(i) is the initial latitude depression angle of the i-th target reference orbit point Q, u1(i) is the latitude depression angle of the offset orbit point obtained after offsetting the i-th target reference orbit point Q by 0.001°, and ΔT is the time corresponding to a 0.001° change in latitude angle from Q0 to Q1. Among them, a is the semi-major axis of the strictly homing orbit, and μ is the gravitational constant of the Earth.

[0102] Calculate the position information of the offset orbit point Q1 corresponding to the latitude depression angle u1(i):

[0103]

[0104]

[0105] in, is the latitude depression angle sequence of the orbital points after migration;

[0106] Then, the position information of the orbit point Q1 in the ground-fixed coordinate system after the offset 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 in the earth-fixed coordinate system when it passes through the intermediate reference orbit point.

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

[0109]

[0110] The velocity V e (i)=[0,0,n earth ]×Q0(i); where n earth is the angular velocity of the Earth's rotation.

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

[0112]

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

[0114] In one example, the vector from Q0 to the target observation point is: Where R aim is the position of the target observation point in the ground-fixed coordinate system, R ain =[R earth ·cos Lat aim ·cos Lon ain ,R earth ·cosLat aim ·sin Lon ain ,R earth ·sin Lat aim ]; R earth is the radius of the Earth.

[0115] calculate Projection in the direction of velocity:

[0116] Calculate the compensation for latitude argument

[0117] Using the compensation value u of latitude argument del Update the latitude depression angle of Q0. The compensated latitude depression angle is the secondary compensated latitude depression angle u0(i): u0(i) = u0(i) + u del .

[0118] (4) The quadratic compensation 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 new intermediate reference orbit point according to the quadratic compensation latitude depression angle.

[0119] In one example, the quadratic compensation latitude depression angle u0(i) is input to the objective function to update Q0(i):

[0120]

[0121] in, is the secondary compensation latitude depression angle sequence;

[0122] Then, the position information of the new intermediate reference orbit point Q0(i) in the earth-fixed coordinate system is: Q0(i) = [XQ0 fixed (i),YQ0 fixed (i),ZQ0 fixed (i)].

[0123] Optionally, the loop (1) to (4) stops when a preset number of times (such as ten times) is reached, and Q0(i) is the position of the target observation point.end (i) = Q0(i), Q end (i) is also the i-th target reference orbit point.

[0124] Step S220, select a target reference orbit point Q that can observe the target observation point according to the threshold. That is, calculate the Earth observation satellite at the target reference orbit point Q end (i) When imaging ground targets, the side viewing angle is used to extract the position where observation can be performed based on the latitude and longitude thresholds and the side viewing angle thresholds. Specifically, it includes the following (i) to (ii):

[0125] (i) Determine the latitude and longitude information and side view information of the target reference orbit point in each strict regression orbit.

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

[0127]

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

[0129] Calculate the side viewing angle ang according to the following formula cs (i)

[0130]

[0131]

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

[0133] The side view direction Tmp2 is calculated according to the following formula:

[0134]

[0135] in, It is an intermediate parameter and has no actual meaning. In one example, if: Tmp2>0, it is right view, otherwise it is left view.

[0136] (ii) If the latitude and longitude information of the target reference orbit point satisfies the preset longitude and latitude constraints, and the side viewing angle information of the target reference orbit point satisfies the preset side viewing angle constraints, it is determined that the earth observation satellite can observe the target observation point when passing through the target reference orbit point, and performs the earth target imaging task for the target observation point according to the longitude and latitude information and the side viewing angle information.

[0137] In practical applications, if the longitude and latitude information [Lat Q (i),Lon Q (i)] The deviation between the latitude and longitude information of the target observation point is within the threshold range, and the side viewing angle ang cs (i) Within the side viewing angle threshold range, then Q end (i) The target observation point can be observed, such as Figure 6 The figure shows an effect diagram of observing a target observation point at a target reference orbit point.

[0138] In summary, the embodiments of the present invention solve the problem of autonomous planning of imaging of earth targets on board, ensure the real-time performance on orbit, and improve the autonomy and redundancy of the satellite; it also avoids the problem of poor accuracy of orbit recursion on board, and uses the nominal reference orbit to calculate the parameters of imaging of earth targets.

[0139] Based on the above-mentioned embodiments, the present invention provides an on-board autonomous mission planning device for imaging ground targets. Figure 7 The schematic diagram of the structure of an on-board autonomous mission planning device for imaging ground targets is shown, and the device mainly includes the following parts:

[0140] Function fitting module 702, used for fitting each strictly regressive orbit of the earth observation satellite to obtain the target function corresponding to each strictly regressive orbit, where the target function is used to describe the mapping relationship between the position information of any orbital point in the strictly regressive orbit and the latitude depression angle;

[0141] The virtual orbit construction module 704 is used to construct a 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, so as to determine the corresponding latitude depression angle sequence when the earth observation satellite runs on each virtual orbit and passes through the target observation point;

[0142] The reference point determination module 706 is used to determine the initial reference orbit point from each strictly regressive orbit based on the latitude depression angle sequence through the objective function, and to perform multiple compensations on the initial reference orbit point to obtain the target reference orbit point in each strictly regressive 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 it passes through the target reference orbit point;

[0143] The mission planning module 708 is used to perform the earth target imaging mission for 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-board autonomous mission planning method for imaging earth targets provided by the embodiment of the present invention determines the initial reference orbit point by fitting the objective function corresponding to each strict regression orbit of the earth observation satellite and constructing the virtual orbit corresponding to each strict regression orbit, and then performs multiple compensations on it to obtain the target reference orbit point that can be used to observe the target observation point, and finally executes the earth target imaging task when the target reference orbit point meets the preset observation constraints. The embodiment of the present invention performs on-board autonomous mission planning by the earth observation satellite, gets rid of the dependence on ground stations, improves the autonomy of the earth observation satellite in orbit and the real-time performance of the earth target imaging mission planning.

[0145] In one implementation, the orbital parameters of the strict regression orbit include the semi-major axis, the eccentricity inclination, the argument of perigee, and the right ascension of the ascending node; the virtual orbit construction module 704 is specifically used for:

[0146] For each strictly regressive orbit, the semi-major axis, eccentricity inclination and perigee argument of the strictly regressive orbit are kept unchanged, the right ascension of the ascending node of the strictly regressive orbit is changed, and the position information of the specified target observation point is combined to construct a virtual orbit passing through the target observation point.

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

[0148] For each strictly regressive orbit, the latitude depression angle sequence is input into the objective function corresponding to the strictly regressive orbit, so that the objective function outputs the position information of the initial reference orbit point for the latitude depression angle sequence.

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

[0150] Based on the position information of the target observation point, the initial reference orbit point is compensated once 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;

[0151] The intermediate reference orbit point is offset to obtain an offset orbit point, and the offset orbit point is used to perform secondary compensation on the intermediate reference orbit point to obtain the position information of a new intermediate reference orbit point, and the new intermediate reference orbit point is continuously offset to obtain a new offset orbit point until a preset loop cutoff condition is met, and the new intermediate reference orbit point obtained at the loop cutoff is used as the target reference orbit point in the strict regression orbit.

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

[0153] Based on the position information of the target observation point, the initial reference orbit point is compensated once to obtain the intermediate reference orbit point in each strict regression orbit, including:

[0154] For each strictly regressive 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 orbital parameters of the strictly regressive orbit;

[0155] 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.

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

[0157] For each strictly regressive 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 objective function corresponding to the strictly regressive orbit, so that the objective function outputs the position information corresponding to the offset orbit point according to the latitude depression angle of the offset orbit point;

[0158] 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 through the intermediate reference orbit point;

[0159] Based on the velocity vector, determine the projection of the vector formed by the intermediate reference orbit point and the offset orbit point in the velocity direction to determine the quadratic compensation latitude depression angle, and input the quadratic compensation latitude depression angle into the objective function corresponding to the strict regression orbit so that the objective function outputs the position information of the new intermediate reference orbit point for the quadratic compensation latitude depression angle.

[0160] In one embodiment, the preset observation constraints include preset latitude and longitude constraints and preset side viewing angle constraints; the task planning module 708 is specifically used to:

[0161] Determine the latitude and longitude information and side view 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 meets the preset longitude and latitude constraints, and the side viewing angle information of the target reference orbit point meets the preset side viewing angle constraints, it is determined that the earth observation satellite can observe the target observation point when passing through the target reference orbit point, and perform the earth target imaging task for the target observation point according to the longitude and latitude information and the side viewing angle information.

[0163] The device provided in the embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0164] An embodiment of the present invention provides an electronic device. Specifically, the electronic device includes a processor and a storage device. The storage device stores a computer program, and when the computer program is executed by the processor, it executes the method described in any one of the above-mentioned implementation methods.

[0165] Figure 8 A structural diagram of an electronic device provided in an embodiment of the present invention, the electronic device 100 includes: a processor 80, a memory 81, a bus 82 and a communication interface 83, wherein the processor 80, the communication interface 83 and the memory 81 are connected via the bus 82; the processor 80 is used to execute an executable module stored in the memory 81, such as a computer program.

[0166] The memory 81 may include a high-speed random access memory (RAM), and may 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 may be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. may be used.

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

[0168] Among them, the memory 81 is used to store programs, and the processor 80 executes the program after receiving the execution instruction. The method executed by the device for flow process definition disclosed in any embodiment of the above-mentioned embodiments of the present invention can be applied to the processor 80 or implemented by the processor 80.

[0169] The processor 80 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 80. The above processor 80 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present invention can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in the embodiments of the present invention can be directly embodied as a hardware decoding processor to be executed, or the hardware and software modules in the decoding processor can be executed. The software module can be located in a mature storage medium in the field such as 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 is located in the memory 81, and the processor 80 reads the information in the memory 81 and completes the steps of the above method in combination with its hardware.

[0170] The computer program product of the readable storage medium provided in the embodiment of the present invention includes a computer-readable storage medium storing program code, and the instructions included in the program code can be used to execute the methods described in the previous method embodiments. The specific implementation can be referred to the previous method embodiments, which will not be repeated here.

[0171] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc., which can store program codes.

[0172] Finally, it should be noted that the above-described embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for autonomous onboard mission planning for imaging of ground targets, characterized in that: The method is applied to an earth observation satellite, comprising: Fitting each strictly regressive orbit of the earth observation satellite to obtain an objective function corresponding to each strictly regressive orbit, wherein the objective function is used to describe a mapping relationship between position information of any orbital point in the strictly regressive orbit and a latitude depression angle; Based on the position information of the designated target observation point and the orbital parameters of each circle of the strict regression orbit, a virtual orbit passing through the target observation point is constructed to determine the latitude depression angle sequence corresponding to when the earth observation satellite runs on each circle of the virtual orbit and passes through the target observation point; By means of the objective function, an initial reference orbit point is determined from each circle of the strict regression orbit based on the latitude depression angle sequence, and the initial reference orbit point is compensated multiple times to obtain a target reference orbit point in each circle of the 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 when passing through the target reference orbit point; If the target reference orbit point in each circle of the strict regression orbit satisfies a preset observation constraint, the earth observation satellite performs an earth target imaging task for the target observation point when passing through the target reference orbit point.

2. The method for autonomous onboard mission planning for ground target imaging according to claim 1, characterized in that: The orbital parameters of the strict regression orbit include semi-major axis, eccentricity inclination, perigee argument, and ascending node right ascension; Based on the position information of the specified target observation point and the orbit parameters of each circle of the strict regression orbit, a virtual orbit passing through the target observation point is constructed, including: For each circle of the strict regression orbit, the semi-major axis, the eccentricity inclination, and the perigee argument of the strict regression orbit are kept unchanged, the right ascension of the ascending node of the strict regression orbit is changed, and the position information of the specified target observation point is combined to construct a virtual orbit passing through the target observation point.

3. The on-board autonomous mission planning method for ground target imaging according to claim 1, characterized in that: Determining an initial reference orbit point from each circle of the strict regression orbit based on the latitude depression angle sequence through the objective function includes: For each circle of the strict regression orbit, the latitude depression angle sequence is input into the objective function corresponding to the strict regression orbit, so that the objective function outputs the position information of the initial reference orbit point for the latitude depression angle sequence.

4. The method for autonomous onboard mission planning for ground target imaging 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 circle of the strict regression orbit: 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 circle 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 processed to obtain an offset orbit point, the intermediate reference orbit point is secondary compensated using the offset orbit point to obtain new position information of the intermediate reference orbit point, and the new intermediate reference orbit point is continuously offset processed to obtain a new offset orbit point until a preset loop cutoff condition is met, and the new intermediate reference orbit point obtained at the loop cutoff is used as the target reference orbit point in the strict regression orbit.

5. The method for autonomous onboard mission planning for ground target imaging according to claim 4, characterized in that: 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 circle of the strict regression orbit, including: 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 circle of the strict regression orbit, including: For each circle of the strict regression orbit, using a spherical triangle algorithm, based on the position information of the target observation point and the orbital parameters of the strict regression orbit, determine the first compensated latitude depression angle corresponding to the initial reference orbit point; 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.

6. The method for autonomous onboard mission planning for ground target imaging according to claim 4, characterized in that: Performing an offset process on the intermediate reference track point to obtain an offset track point, and performing secondary compensation on the intermediate reference track point using the offset track point to obtain new position information of the intermediate reference track point, including: For each circle of the 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 objective function corresponding to the strict regression orbit, so that the objective function outputs the position information corresponding to the offset orbit point according to the latitude depression angle of the offset orbit point; Determining, based on the position information corresponding to the offset orbit point, a velocity vector of the earth observation satellite in an earth-fixed coordinate system when the earth observation satellite passes through the intermediate reference orbit point; Based on the velocity vector, determine the projection of the vector formed by the intermediate reference orbit point and the offset orbit point in the velocity direction to determine the secondary compensation latitude depression angle, and input the secondary compensation latitude depression angle 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 method for autonomous onboard mission planning for ground target imaging according to claim 1, characterized in that: The preset observation constraints include preset longitude and latitude constraints and preset side viewing angle constraints; if the target reference orbit point in each circle of the strict regression orbit satisfies the preset observation constraints, then when the earth observation satellite passes through the target reference orbit point, performing an earth target imaging task for the target observation point, including: Determine the latitude and longitude information and side viewing angle information of the target reference orbit point in each circle of the strict regression orbit; If the longitude and latitude information of the target reference orbit point satisfies the preset longitude and latitude constraints, and the side viewing angle information of the target reference orbit point satisfies the preset side viewing angle constraints, it is determined that the earth observation satellite can observe the target observation point when passing through the target reference orbit point, and performs the earth target imaging task for the target observation point according to the longitude and latitude information and the side viewing angle information.

8. An onboard autonomous mission planning device for imaging ground targets, characterized in that: The device is applied to an earth observation satellite, and comprises: A function fitting module, used for fitting each strict regression orbit of the earth observation satellite to obtain an objective function corresponding to each strict regression orbit, wherein 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; A virtual orbit construction module is used to construct a 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 circle of the strict regression orbit, so as to determine the latitude depression angle sequence corresponding to when the earth observation satellite runs on each circle of the virtual orbit and passes through the target observation point; A reference point determination module, configured to determine an initial reference orbit point from each circle of the strict regression orbit based on the latitude depression angle sequence through the objective function, and to perform multiple compensations on the initial reference orbit point to obtain a target reference orbit point in each circle of the 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 when it passes through the target reference orbit point; The mission planning module is used to perform the earth target imaging mission for the target observation point when the earth observation satellite passes through the target reference orbit point if the target reference orbit point in each circle of the strict regression orbit meets the preset observation constraint.

9. An electronic device, characterized in that: The method comprises a processor and a memory, wherein the memory stores computer executable instructions that can be executed by the processor, and the processor executes the computer executable instructions to implement the method according to 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, and when the computer-executable instructions are called and executed by a processor, the computer-executable instructions prompt the processor to implement the method according to any one of claims 1 to 7.

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