A method and system for planning onboard missions of satellites with reduced ground speed and push-to-sweep capability.

Abstract

This invention provides a method and system for on-board pushbroom mission planning with reduced ground velocity. The method includes: first, calculating the desired attitude Euler angles for pushbroom at 1x ground velocity using Newton's iteration method, and determining the time when the satellite reaches the geometric center of the survey area. Then, a reduced ground velocity pushbroom mode control algorithm is provided, which calculates the satellite's desired attitude, current attitude, desired attitude angular velocity, and current attitude angular velocity during reduced ground velocity pushbroom. Finally, the reduced ground velocity pushbroom mode control algorithm is used to determine the start and end times of stable reduced ground velocity pushbroom, completing the on-board pushbroom mission planning. This invention not only proposes a method for on-board mission planning with reduced ground velocity but also a specific reduced ground velocity pushbroom mode control algorithm, enabling the satellite to complete the pushbroom mission with the desired attitude and achieving high-precision controllability.

Description

Technical Field

[0001] This invention relates to the field of satellite mission planning technology, and in particular to a method and system for on-board mission planning with reduced ground speed push-broom. Background Technology

[0002] Existing agile optical remote sensing satellites rely on their rapid attitude maneuverability to complete high-precision imaging of ground areas in a short period of time when performing missions.

[0003] However, traditional pushbroom missions typically employ a fixed ground-velocity pushbroom method, limiting the satellite's adaptability to special environments or requirements. Especially when long-duration, high-precision observations or coverage of specific areas are needed, a fixed pushbroom velocity cannot meet the demands. Therefore, in recent years, various new pushbroom modes and control methods have been proposed for remote sensing satellites to improve mission flexibility and efficiency. Some existing solutions have improved the completion rate of satellite imaging missions by increasing the satellite's attitude maneuverability and optimizing the pushbroom path, but certain shortcomings remain, particularly under complex observation conditions, where traditional methods have limitations in precisely controlling attitude and velocity. Summary of the Invention

[0004] This invention provides a method and system for planning satellite missions with reduced ground speed and push-to-sweep capability, in order to overcome the deficiencies in the existing technology.

[0005] In a first aspect, the present invention provides a method for planning on-board missions with reduced ground velocity push-sweep, comprising:

[0006] Based on the spatial geometric relationship between the satellite, ground target point and the Earth, calculate the expected attitude Euler angle and the time when the push sweep reaches the ground point at the geometric center of the survey area when pushing sweep at 1 times the ground speed.

[0007] The ground speed push-broom mode control algorithm is adopted to calculate the expected attitude quaternion from the inertial frame to the camera coordinate system, the expected attitude quaternion from the inertial frame to the satellite body frame, and the expected total attitude angular velocity during the ground speed push-broom of the satellite without yaw angle correction. The current attitude quaternion and the current attitude angular velocity of the satellite are obtained from the satellite attitude determination.

[0008] Calculate the start time of the satellite's ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, as well as the end time of the ground velocity stabilization push-broom and the corresponding desired attitude Euler angles.

[0009] Calculate the satellite's ground velocity push-broom start time and desired attitude Euler angles.

[0010] According to the present invention, a method for on-board mission planning of a ground-velocity push-broom system is provided, which calculates the desired attitude Euler angles and the time when the push-broom reaches the geometric center of the mapping area based on the spatial geometric relationship between the satellite, the ground target point, and the Earth, including:

[0011] The desired attitude pitch angle for push-sweep at 1x ground speed is determined as follows: At the same time, establish the geometric relationship between the satellite and the ground point at the geometric center of the mapping area;

[0012] Based on the geometric relationship between the satellite and the ground point at the geometric center of the mapping area, establish the satellite's overpass time function;

[0013] The zeros of the overpass time function are determined using Newton's method, and the time when the broom reaches the geometric center of the surveyed area at 1x speed is calculated. ;

[0014] Time from 1x speed push sweep to the ground point of the geometric center of the survey area Calculate the desired attitude Euler angles for push sweeping at 1x ground velocity. .

[0015] According to the present invention, a method for on-board mission planning with reduced ground velocity push-broom configuration is provided, which calculates the desired attitude quaternions from the inertial frame to the satellite's own frame, including:

[0016] The result is obtained from the dynamic link library based on the deflection angle calculation. :

[0017]

[0018] in, Let be a unit vector, representing the direction of the rotation axis. This is the rotational quaternion after correction for the deflection angle;

[0019] The desired attitude quaternion from the orbital system to the camera coordinate system after adding the yaw angle correction is:

[0020]

[0021] The attitude quaternions from the satellite's intrinsic coordinate system to the corresponding camera coordinate system are determined as follows: Then the expected attitude quaternion of the inertial frame to the satellite's own frame is:

[0022] .

[0023] According to the present invention, a satellite-to-satellite mission planning method for ground-velocity push-brooming is provided, which calculates the desired total angular velocity of the satellite during ground-velocity push-brooming, including:

[0024] The attitude angle rotation sequence, including yaw angle correction, is determined to be 3213, with the c-axis representing the camera coordinate system and the b-axis representing the satellite body coordinate system.

[0025] Yaw angle of the first rotation around the Zc axis , The second rotation around the Yc axis, pitch angular velocity Perform push sweeping, and These are the desired pitch angles for the current and previous control cycles, the third rotation around the Xc axis, and the roll angle. Perform push sweeping, and These are the desired attitude roll angles for the current and previous control cycles, the yaw angle correction for the fourth rotation around the Zb axis, and the yaw rate. The angular velocity of the satellite relative to the orbital system, projected onto the camera coordinate system, can be obtained from the eccentricity calculation dynamic link library.

[0026]

[0027] M1 represents the rotation matrix around the X-axis, M2 represents the rotation matrix around the Y-axis, and M3 represents the rotation matrix around the Z-axis.

[0028] The projection of the satellite's angular velocity relative to the orbital system onto its body coordinate system is:

[0029]

[0030] The entrainment angular velocity of the orbital system is Projecting onto the satellite's body coordinate system yields:

[0031]

[0032] This represents the proportion of the satellite's ground velocity.

[0033] The desired total angular velocity of the satellite is obtained as follows:

[0034] .

[0035] According to the present invention, a method for on-board mission planning of a deceleration-stabilized pushbroom satellite is provided, which calculates the start time of the deceleration-stabilized pushbroom and the corresponding desired attitude Euler angles, including:

[0036] The ground speed reduction ratio is determined as follows: The total time for ground velocity stabilization push sweeping is Combined with the time it takes to push the broom to the geometric center of the surveyed area at 1x speed Obtain the start time of stable ground velocity push sweeping ;

[0037] Obtain satellite location Ground sweeping point at the moment of sweeping at 1 times ground speed and the satellite's position Actual ground push point at the start of stable ground velocity push sweep , The corresponding time is ;

[0038] The calculation was obtained using the ground velocity push-broom control algorithm. and Calculate the corresponding desired attitude Euler angles. .

[0039] According to the present invention, a method for on-board mission planning of a deceleration-stabilized push-broom system is provided, which calculates the end time of the deceleration-stabilized push-broom and the corresponding desired attitude Euler angles, including:

[0040] Determine the end time of stable ground velocity push sweeping The satellite position corresponding to push-broom operation at 1x ground speed is Ground sweeping point is ;

[0041] Obtain satellite location Actual ground push point at the end of the push sweep with reduced ground velocity , The corresponding time is ;

[0042] The calculation was obtained using the ground velocity push-broom control algorithm. and Calculate the corresponding desired attitude Euler angles. .

[0043] According to the present invention, a method for on-board mission planning of a satellite with decreasing ground velocity push-broom is provided, which calculates the satellite's decreasing ground velocity push-broom start time and desired attitude Euler angles, including:

[0044] Calculate the pitch rate during ground velocity stabilization push sweeping. and rolling angular velocity Through pitch angular velocity Interpolation to obtain the start time of the deceleration push sweep. ;

[0045] Calculate the start time of ground velocity push sweeping ,Depend on , , Obtain the Euler angles of the desired pose .

[0046] Secondly, the present invention also provides a ground-speed push-sweep satellite mission planning system, comprising:

[0047] The first calculation module is used to calculate the expected attitude Euler angles and the time when the push sweep reaches the geometric center of the survey area based on the spatial geometric relationship between the satellite, the ground target point and the Earth.

[0048] The second calculation module is used to calculate the expected attitude quaternion from the inertial frame to the camera coordinate system, the expected attitude quaternion from the inertial frame to the satellite body frame, and the expected total attitude angular velocity of the satellite during the ground speed push-broom mode control algorithm without yaw angle correction when the satellite is pushed-broomed at ground speed. The current attitude quaternion and the current attitude angular velocity of the satellite are obtained from the satellite attitude determination.

[0049] The third calculation module is used to calculate the start time of the satellite's ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, as well as the end time of the ground velocity stabilization push-broom and the corresponding desired attitude Euler angles.

[0050] The fourth calculation module is used to calculate the satellite's ground velocity push-broom start time and desired attitude Euler angles.

[0051] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the mission planning method for ground speed push-sweep satellites as described above.

[0052] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the on-board mission planning method for ground-speed push-sweep as described above.

[0053] The present invention provides a method and system for on-board mission planning with reduced ground velocity push-broom, which, through a specific algorithm for controlling the push-broom mode, enables the satellite to complete push-broom imaging of a ground area within a specific time period at less than 1 times the ground velocity. By accurately calculating the satellite's desired attitude and the start and end times of the push-broom, this invention ensures that the satellite performs the push-broom mission at the desired attitude and velocity, significantly improving mission flexibility and imaging accuracy. This technical solution can meet the special needs of satellites in complex observation missions, adapt to different terrains and observation targets, and achieve more efficient imaging mission planning. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0055] Figure 1 This is a flowchart illustrating the satellite mission planning method for reducing ground speed and pushing and sweeping provided by the present invention.

[0056] Figure 2 This is a schematic diagram of the spatial geometry of the ground velocity push-broom provided by the present invention;

[0057] Figure 3 This is a schematic diagram of the total pointing deviation under the reduced ground speed push-broom mode provided by the present invention;

[0058] Figure 4 This is a schematic diagram of the elevation angle deviation of the satellite orbit system under the reduced ground speed push-broom mode provided by the present invention;

[0059] Figure 5 This is a schematic diagram of the roll angle deviation of the satellite orbit system under the reduced ground velocity push-broom mode provided by the present invention;

[0060] Figure 6 This is a schematic diagram of the yaw angle deviation of the satellite orbital system under the reduced ground speed push-broom mode provided by the present invention;

[0061] Figure 7 This is a schematic diagram of the satellite X-axis angular velocity deviation under the ground velocity push-broom mode provided by the present invention;

[0062] Figure 8 This is a schematic diagram of the satellite Y-axis angular velocity deviation under the ground velocity push-broom mode provided by the present invention;

[0063] Figure 9 This is a schematic diagram of the satellite Z-axis angular velocity deviation under the reduced ground velocity push-broom mode provided by the present invention;

[0064] Figure 10 This is a schematic diagram of the satellite X-axis angular velocity in the ground velocity push-broom mode provided by the present invention;

[0065] Figure 11 This is a schematic diagram of the satellite's Y-axis angular velocity under the reduced ground velocity push-broom mode provided by the present invention;

[0066] Figure 12 This is a schematic diagram of the satellite Z-axis angular velocity in the ground velocity push-broom mode provided by the present invention;

[0067] Figure 13 This is a schematic diagram of the structure of the ground speed reduction push-sweep satellite mission planning system provided by the present invention;

[0068] Figure 14 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0069] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0070] To address the problems existing in existing technologies, this invention proposes a reduced-ground-velocity pushbroom on-board mission planning method based on the attitude control technology of agile optical remote sensing satellites. This method, through a specific reduced-ground-velocity pushbroom mode control algorithm, enables the satellite to complete pushbroom imaging of a ground area within a specific time period at less than 1 times the ground velocity. By accurately calculating the satellite's desired attitude and the start and end times of pushbrooming, this invention ensures that the satellite performs the pushbroom mission at the desired attitude and velocity, significantly improving mission flexibility and imaging accuracy. This technical solution can meet the special needs of satellites in complex observation missions, adapt to different terrains and observation targets, and achieve more efficient imaging mission planning.

[0071] Figure 1 This is a flowchart illustrating the onboard mission planning method for reducing ground velocity and pushing and scanning satellites provided in an embodiment of the present invention, as shown below. Figure 1 As shown, it includes:

[0072] Step 100: Based on the spatial geometric relationship between the satellite, the ground target point, and the Earth, calculate the expected attitude Euler angles and the time when the push sweep reaches the geometric center of the survey area at 1 times the ground speed.

[0073] Step 200: Using the ground speed push-broom mode control algorithm, calculate the expected attitude quaternion from the inertial frame to the camera coordinate system without yaw angle correction, the expected attitude quaternion from the inertial frame to the satellite's own frame, and the expected total attitude angular velocity during the ground speed push-broom. Obtain the current attitude quaternion and the current attitude angular velocity of the satellite from the satellite attitude determination.

[0074] Step 300: Calculate the start time of the satellite's ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, as well as the end time of the ground velocity stabilization push-broom and the corresponding desired attitude Euler angles;

[0075] Step 400: Calculate the satellite's ground velocity push-broom start time and desired attitude Euler angles.

[0076] It should be noted that the main purpose of this invention is to enable a satellite to perform push-broom imaging of a ground area at less than 1 times the ground speed over a period of time, where the Euler angles involved are all in 321 revolution order. In this mode, when the satellite is in the Earth's shadow region, the hyperspectral camera performs push-broom imaging at a constant proportion of the ground speed. First, the desired attitude Euler angles for push-broom imaging at 1 times the ground speed are calculated using Newton's iteration method, along with the time when the satellite reaches the geometric center of the mapping area. Then, a control algorithm for the reduced ground speed push-broom mode is provided, which calculates the satellite's desired attitude, current attitude, desired attitude angular velocity, and current attitude angular velocity during reduced ground speed push-broom imaging. Finally, the reduced ground speed push-broom mode control algorithm is used to determine the start and end times of the stable reduced ground speed push-broom, completing the onboard push-broom mission planning.

[0077] Specifically, the process of this embodiment of the invention includes the following steps:

[0078] Step 1: Calculate the desired attitude Euler angles for push sweeping at 1x ground velocity. The moment when the broom reaches the geometric center of the surveyed area. Specifically, it includes the following steps:

[0079] Step 1.1, the desired pitch angle during 1x ground speed push-broom is: The geometric relationship between the satellite and the ground point at the geometric center of the mapping area is established as follows;

[0080] like Figure 2 As shown, when the satellite push-broom reaches the ground point T, the geometric center of the mapping area, the geocentric vector of the ground point T is denoted as... The geocentric radius of satellite S is denoted as Speed ​​is denoted as , causing yaw angle , This represents the vector from ground point T to satellite position S. Let represent the angular momentum vector, describing the direction of the satellite's orbital plane in inertial space. Then, the satellite's attitude corresponds to... The axis direction is:

[0081]

[0082] Let the pitch angle be 1 times the ground speed for push sweeping. ,but The axis and the geocentric radius of the satellite Angle between the radius and the vector And since the satellite-target line does not pass through the Earth, we have:

[0083]

[0084] The satellite overpass time function established in step 1.2 is as follows:

[0085] The conditions for the satellite's overhead transit are:

[0086]

[0087] The overpass time function constructed based on the above formula is:

[0088]

[0089] Taking the derivative, we get:

[0090]

[0091] when The time is the moment the satellite passes overhead.

[0092] In step 1.3, Newton's method is used to find the function. The zero point is used to determine the time of the overpass.

[0093] Let the initial value be... During each iteration:

[0094]

[0095] when and The difference is less than a certain small quantity When the solution process converges, The iteration ends when the numerical solution of the equation is obtained.

[0096] If the number of iterations exceeds a certain upper limit If the initial value still does not converge, then it is considered unreliable. Note The value should not be too large, otherwise there is a possibility of convergence to zero points in other visible segments. Considering the fast convergence characteristics of Newton's iteration method, this invention takes... .

[0097] Initial value The selection is as follows, based on the first orbital period (in terms of...). for The latitude of the satellite entering and exiting the quasi-visible phase within the starting point of its orbital period is used to calculate the estimated true anomaly angle at those times. The perigee argument is then used to replace the perigee argument at any given moment within that period, and the true anomaly angle is used... Angle with near point The relationship and the angle of proximity and time The relationship can be used to determine the time of entry and exit from the quasi-visible segment.

[0098] The geocentric longitude of the satellite varies depending on whether it is a ascending or descending orbit. and These represent the upper and lower bounds of the satellite's geocentric longitude during the ascent phase. and The upper and lower bounds of the satellite's geocentric longitude during the descent phase. Combined with... , , , And the time of entering and exiting the quasi-visible segment, to obtain the longitude of the nadir point at the time of entering and exiting the quasi-visible segment, i.e. , , and . and These represent the upper and lower bounds of the longitude of the nadir point at the moment of entering the quasi-visible period. and These represent the upper and lower bounds of the longitude of the nadir point at the moment of exiting the quasi-visible period. Note that after solving, [the following will be applied]. The range of values ​​is limited to .

[0099] Taking longitude From leap to The possibility, for any Let L represent the longitude of the satellite's nadir. When L meets the following conditions, it indicates that the satellite is within the visible area, that is, the forward and retrograde orbits are different.

[0100]

[0101] Then the corresponding and As a set of feasible initial values ​​to be substituted Solve for it in the middle.

[0102] Similarly, if (the forward and reverse tracks are different)

[0103]

[0104] Then the corresponding and As a set of feasible initial values ​​to be substituted Solve for it in the middle.

[0105] Otherwise, the first The orbital period does not have the capability to target The possibility of observation is not involved in the solution process.

[0106] This screening process can also avoid... This is unreasonable.

[0107] Finally, the initial values ​​are substituted into the observation equation. Solution time .

[0108] Step 1.4: Calculate the time it takes for the satellite push-broom to reach the geometric center of the ground point in the mapping area. Then, the position of the target in the inertial frame can be determined. ,speed And the satellite's position in the inertial frame. ,speed Yaw angle Then the desired attitude coordinate system of the satellite is:

[0109]

[0110] The satellite's current orbital coordinate system is:

[0111]

[0112] The desired attitude Euler angles during satellite push-brooming

[0113] .

[0114] Step 2, the specific process of the control algorithm for the reduced ground speed push sweep mode is as follows;

[0115] Step 2.1 Calculate the desired attitude quaternion from the inertial frame to the camera coordinate system without yaw angle correction during satellite ground velocity pushbroom. , as follows:

[0116] This mode involves the hyperspectral camera performing push-broom motion at a constant ground velocity when the satellite is in the Earth's shadow region. The coordinate system during hyperspectral operation is defined as the coordinates from the home system to the hyperspectral camera coordinate system. The attitude quaternions from the satellite's own coordinate system to the corresponding camera coordinate system can be obtained. .

[0117] 321 Transition to the next sequence The initial expected attitude Euler angles at time t are The satellite from Starting at a certain time, sweeping is performed at a constant ground velocity, let the ratio be 1. That is, the ground velocity of the satellite payload optical axis pushbroom is ,in For the satellite, use attitude Euler angles During normal ground sweeping, the moving speed of the time axis pointing to the ground point is 1 times the ground speed.

[0118] exist At that moment, the satellite position changed from Exercise If the satellite performs normal Earth push-brooming, the attitude Euler angles are: Its optical axis points to the ground point as If the satellite performs a ground-based pushbroom at a reduced velocity, the point on the ground that its optical axis points to is... It is easy to see that the ground point and At that moment, the satellite's position moved to Normal ground-pushing sweep, attitude Euler angles are The timeline points to the same ground point. Find... and After obtaining the coordinates, use and The relationship can be used to determine the satellite's position. The expected posture at all times.

[0119] The coordinates are The position of the satellite can be directly obtained from the orbit in the J2000 inertial frame, and then transferred to the WGS84 Earth-fixed frame.

[0120] Next, please ask... The coordinates are first obtained through orbit prediction. Time, satellite position Then, by attitude Euler angles The ground point can be determined. Specifically, let's assume... The coordinates under the WGS84 geofixed system are: ( time), The coordinates under the WGS84 geofixed system are: ( (moment), vector The unit vector under the WGS84 geofixed system is ( (At any given moment), this vector can be obtained from the attitude Euler angles during normal ground push-broom operation. Seeking. And. ,but

[0121]

[0122] Due to ground points On the Earth's surface, it is considered to be an oblate spheroid.

[0123]

[0124] The formula Substituting into the above equation, we can obtain:

[0125] because You shouldn't wear Earth. Take the smaller of the two. From this, we can obtain the ground point. Coordinates under the WGS84 geofixed system ( time).

[0126] Depend on Coordinates under the WGS84 geofixed system ( (moment), get The coordinates under the WGS84 geofixed system are still […]. ( (moment), will The coordinates in the WGS84 Earth-Fixed Frame are transformed into the inertial frame as follows: ( (Time). Also. Coordinates in an inertial frame ( (Time), the satellite can be obtained at Vector coordinates of the load at any given time Therefore, the satellite's position can be determined. The attitude of the inertial frame at time t is the desired attitude quaternion from the inertial frame to the camera coordinate system without yaw angle correction. .

[0127] Step 2.2, calculate the desired attitude quaternion from the inertial frame to the satellite's own frame. , as follows:

[0128] First, the pose obtained in step 2.1 Flow angle correction is required. This is calculated using a dynamic link library based on the flow angle calculation. .

[0129]

[0130] The desired attitude quaternion from the orbital system to the camera coordinate system after adding the yaw angle correction is:

[0131]

[0132] Since the attitude quaternion from the satellite's own coordinate system to the corresponding camera coordinate system is Then the expected attitude quaternion of the inertial frame to the satellite's own frame is:

[0133]

[0134] Step 2.3: Calculate the desired total attitude angular velocity during satellite ground velocity push-broom operation. , as follows:

[0135] First, calculate the relative angular velocity with respect to the orbital frame. Since the attitude angle rotation sequence, including yaw correction, is 3213, the yaw angle of the first rotation about the Zc axis is... , The second rotation around the Yc axis, pitch angular velocity Perform push sweeping, and These are the desired pitch angles for the current and previous control cycles, respectively; the roll angle for the third rotation around the Xc axis. Perform push sweeping, and These are the desired attitude roll angles for the current and previous control cycles, respectively; the yaw angle correction is performed during the fourth rotation around the Zb axis, and the yaw rate is... This can be obtained from the yaw angle calculation dynamic link library. Here, subscript c represents the camera coordinate system, and subscript b represents the satellite body coordinate system. M1 represents the rotation matrix around the X-axis, M2 represents the rotation matrix around the Y-axis, and M3 represents the rotation matrix around the Z-axis. The projection of the satellite's angular velocity relative to the orbital system onto the camera coordinate system is:

[0136]

[0137] The projection of the satellite's angular velocity relative to the orbital system onto its body coordinate system is:

[0138]

[0139] On the other hand, the entrainment angular velocity of the orbital system is Projecting it onto the satellite's body coordinate system yields:

[0140]

[0141] The expected total angular velocity of the satellite is

[0142]

[0143] Step 2.4, obtain the quaternion of the satellite's current attitude. and the satellite's current attitude angular velocity ;

[0144] Satellite current attitude quaternion The current attitude angular velocity of the satellite is obtained from attitude determination. Acquired by attitude determination.

[0145] Step 3, calculate the start time of ground velocity stabilization push sweeping. Desired attitude Euler angle , as follows:

[0146] Given the ratio of ground speed decreases as follows: The total time for ground velocity stabilization push sweeping is Then the ground velocity stabilizes and the push sweep begins at the start time. The satellite is in Figure 2 middle If the sweeping is performed at 1x ground speed, the ground point swept will be... At the start of the ground velocity stabilization push sweep, the actual ground point being swept is... This is equivalent to the satellite being located in Figure 2 middle The time corresponding to the ground point swept at 1 times the ground speed is Using the speed reduction push-broom control algorithm in step 2, the following can be calculated: , The desired attitude Euler angles are then calculated. ( , , ).

[0147] Step 4: Calculate the end time of ground velocity stabilization push sweeping. Desired attitude Euler angle , as follows:

[0148] End of push sweeping at reduced speed The satellite is in Figure 2 middle If the sweeping is performed at 1x ground speed, the ground point swept will be... At the end of the ground sweeping operation with reduced ground velocity, the actual ground point swept is... This is equivalent to the satellite being located in the image. The time corresponding to the ground point swept at 1 times the ground speed is Similarly, using the speed reduction push-broom control algorithm from step 2, the following calculations are performed: , Further calculate the Euler angles of the desired pose. ( , , ).

[0149] Step 5, calculate the start time of the ground velocity push-broom and the desired attitude Euler angles, which includes the following two steps:

[0150] Step 5.1, calculate the pitch angular velocity during ground velocity stabilization push sweeping. Rolling angular velocity Through pitch angular velocity Interpolation to obtain the maneuver time at the start of the ground speed reduction push sweep .

[0151] During ground speed stabilization push sweeping, pitch angular velocity Rolling angular velocity Through pitch angular velocity Interpolation to obtain the maneuver time at the start of the ground speed reduction push sweep .

[0152] Step 5.2, calculate the start time of ground velocity reduction push sweeping. Desired attitude Euler angle .

[0153] Deceleration push sweep start time Desired attitude Euler angle Depend on , , It can be obtained.

[0154] Based on the above embodiments, in order to verify the effectiveness of the present invention in mission planning for the ground-rate push-broom satellite of the agile remote sensing optical satellite, the parameters used for on-orbit testing of the satellite are as follows:

[0155] I. Target Parameters

[0156] Longitude 139.7°

[0157] Latitude 35.7°

[0158] 41m in height

[0159] Maximum roll angle of ground speed push sweeper: 30°

[0160] Solar altitude angle: -26°

[0161] II. Command Parameters

[0162] Ground speed reduction mode starts at 489761498s

[0163] Imaging begins at 489761520s

[0164] Broom push duration 120s

[0165] Yaw angle 0°

[0166] Pitch angle 37.9350°

[0167] Roll angle 4.3251°

[0168] Pitch angular velocity -0.46302813° / s

[0169] Rolling angular velocity -0.02335323° / s

[0170] Let the ground speed reduction ratio be Based on the above parameters, on-orbit testing of the satellite was conducted, and simulations were performed on the ground speed reduction planning and control method. The results are as follows:

[0171] The expected Euler angles are (0, 0, 26.164730)°, the total pointing deviation during the ground velocity push-broom period is 0.25° (3σ), the X-axis attitude stability is 0.002° / s (3σ), the Y-axis attitude stability is 0.001° / s (3σ), and the Z-axis attitude stability is 0.005° / s (3σ).

[0172] like Figures 3 to 12 The simulation results verify that the ground velocity push-broom imaging planning and control method proposed in this invention can achieve rapid dynamic response and stable adjustment during satellite attitude control, and the attitude error gradually converges to a low level, meeting the imaging accuracy requirements and ensuring the successful completion of the on-orbit mission.

[0173] The mission planning system for satellites with reduced ground speed and push-broom capability provided by this invention is described below. The mission planning system for satellites with reduced ground speed and push-broom capability described below can be referred to in correspondence with the mission planning method for satellites with reduced ground speed and push-broom capability described above.

[0174] Figure 13 This is a schematic diagram of the structure of the ground-speed-reducing push-sweep satellite mission planning system provided in an embodiment of the present invention, as shown below. Figure 13 As shown, it includes: a first calculation module 1301, a second calculation module 1302, a third calculation module 1303, and a fourth calculation module 1304, wherein:

[0175] The first calculation module 1301 is used to calculate the desired attitude Euler angles and the time when the satellite pushes to the ground point at the geometric center of the mapping area, based on the spatial geometric relationship between the satellite, the ground target point, and the Earth. The second calculation module 1302 is used to calculate the desired attitude quaternions from the inertial frame to the camera coordinate system, the desired attitude quaternions from the inertial frame to the satellite's own frame, and the desired total angular velocity of the satellite during the reduced ground speed push, respectively, using the reduced ground speed push mode control algorithm. The current attitude quaternions and the current attitude angular velocity of the satellite are obtained from the satellite attitude determination. The third calculation module 1303 is used to calculate the start time of the reduced ground speed stable push and the corresponding desired attitude Euler angles, as well as the end time of the reduced ground speed stable push and the corresponding desired attitude Euler angles. The fourth calculation module 1304 is used to calculate the start time of the reduced ground speed push and the desired attitude Euler angles.

[0176] Figure 14 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 14As shown, the electronic device may include: a processor 1410, a communications interface 1420, a memory 1430, and a communication bus 1440, wherein the processor 1410, the communications interface 1420, and the memory 1430 communicate with each other through the communication bus 1440. The processor 1410 can call logic instructions in the memory 1430 to execute a reduced-speed pushbroom on-board mission planning method. This method includes: calculating the desired attitude Euler angles and the time when the pushbroom reaches the geometric center of the mapping area at 1x ground speed based on the spatial geometric relationship between the satellite, the ground target point, and the Earth; using a reduced-speed pushbroom mode control algorithm, calculating the desired attitude quaternions from the inertial frame to the camera coordinate system without yaw angle correction, the desired attitude quaternions from the inertial frame to the satellite's own frame, and the desired total angular velocity of the satellite during reduced-speed pushbroom; obtaining the current attitude quaternions and the current attitude angular velocity of the satellite based on the satellite attitude determination; calculating the start time of the reduced-speed stable pushbroom and the corresponding desired attitude Euler angles, as well as the end time of the reduced-speed stable pushbroom and the corresponding desired attitude Euler angles; and calculating the start time of the reduced-speed pushbroom and the desired attitude Euler angles.

[0177] Furthermore, the logical instructions in the aforementioned memory 1430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0178] On the other hand, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon. When executed by a processor, the computer program implements the on-board mission planning method for reduced ground velocity pushbroom provided by the above methods. The method includes: calculating the desired attitude Euler angles and the time when the pushbroom reaches the geometric center ground point of the mapping area during pushbroom operation at 1x ground velocity, based on the spatial geometric relationship between the satellite, the ground target point, and the Earth; using a reduced ground velocity pushbroom mode control algorithm, calculating the desired attitude quaternions from the inertial frame to the camera coordinate system, the desired attitude quaternions from the inertial frame to the satellite's own frame, and the desired total angular velocity of the satellite during reduced ground velocity pushbroom operation, respectively; obtaining the current attitude quaternions and the current attitude angular velocity of the satellite from the satellite attitude determination; calculating the start time of the reduced ground velocity stable pushbroom operation and the corresponding desired attitude Euler angles, as well as the end time of the reduced ground velocity stable pushbroom operation and the corresponding desired attitude Euler angles; and calculating the start time of the reduced ground velocity pushbroom operation and the desired attitude Euler angles.

[0179] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0180] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for planning onboard missions of a satellite with reduced ground velocity push-sweep, characterized in that, include: Based on the spatial geometric relationship between the satellite, ground target point and the Earth, calculate the expected attitude Euler angle and the time when the push sweep reaches the ground point at the geometric center of the survey area when pushing sweep at 1 times the ground speed. The ground speed push-broom mode control algorithm is adopted to calculate the expected attitude quaternion from the inertial frame to the camera coordinate system, the expected attitude quaternion from the inertial frame to the satellite body frame, and the expected total attitude angular velocity during the ground speed push-broom of the satellite without yaw angle correction. The current attitude quaternion and the current attitude angular velocity of the satellite are obtained from the satellite attitude determination. Calculate the start time of the satellite's ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, as well as the end time of the ground velocity stabilization push-broom and the corresponding desired attitude Euler angles. Calculate the satellite's ground velocity push-broom start time and desired attitude Euler angles.

2. The method for planning satellite-to-ground missions with reduced ground velocity and push-to-sweep capability according to claim 1, characterized in that, Based on the spatial geometric relationship between the satellite, ground target point, and Earth, calculate the expected attitude Euler angles and the time when the push sweep reaches the geometric center of the surveyed area at 1x ground velocity, including: The desired attitude pitch angle for push-sweep at 1x ground speed is determined as follows: At the same time, establish the geometric relationship between the satellite and the ground point at the geometric center of the mapping area; Based on the geometric relationship between the satellite and the ground point at the geometric center of the mapping area, establish the satellite's overpass time function; The zeros of the overpass time function are determined using Newton's method, and the time when the broom reaches the geometric center of the surveyed area at 1x speed is calculated. ; Time from 1x speed push sweep to the ground point of the geometric center of the survey area Calculate the desired attitude Euler angles for push sweeping at 1x ground velocity. .

3. The method for planning satellite-to-ground missions with reduced ground velocity and push-to-sweep capability according to claim 1, characterized in that, Calculate the desired attitude quaternion from the inertial frame to the satellite's own frame, including: The result is obtained from the dynamic link library based on the deflection angle calculation. : in, Let be a unit vector, representing the direction of the rotation axis. This is the rotational quaternion after correction for the deflection angle; The desired attitude quaternion from the orbital system to the camera coordinate system after adding the yaw angle correction is: The attitude quaternions from the satellite's intrinsic coordinate system to the corresponding camera coordinate system are determined as follows: Then the expected attitude quaternion of the inertial frame to the satellite's own frame is: 。 4. The method for planning satellite-to-ground missions with reduced ground velocity and push-sweep capability according to claim 3, characterized in that, The calculation of the desired total attitude angular velocity during satellite ground velocity push-broom includes: The attitude angle rotation sequence, including yaw angle correction, is determined to be 3213, with the c-axis representing the camera coordinate system and the b-axis representing the satellite body coordinate system. Yaw angle of the first rotation around the Zc axis , The second rotation around the Yc axis, pitch angular velocity Perform push sweeping, and These are the desired pitch angles for the current and previous control cycles, the third rotation around the Xc axis, and the roll angle. Perform push sweeping, and These are the desired attitude roll angles for the current and previous control cycles, the yaw angle correction for the fourth rotation around the Zb axis, and the yaw rate. The angular velocity of the satellite relative to the orbital system, projected onto the camera coordinate system, can be obtained from the eccentricity calculation dynamic link library. M1 represents the rotation matrix around the X-axis, M2 represents the rotation matrix around the Y-axis, and M3 represents the rotation matrix around the Z-axis. The projection of the satellite's angular velocity relative to the orbital system onto its body coordinate system is: The entrainment angular velocity of the orbital system is Projecting onto the satellite's body coordinate system yields: This represents the proportion of the satellite's ground velocity. The desired total angular velocity of the satellite is obtained as follows: 。 5. The method for planning satellite-to-ground missions with reduced ground velocity and push-to-sweep capability according to claim 1, characterized in that, Calculate the start time of the satellite's ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, including: The ground speed reduction ratio is determined as follows: The total time for ground velocity stabilization push sweeping is Combined with the time it takes to push the broom to the geometric center of the surveyed area at 1x speed Obtain the start time of stable ground velocity push sweeping ; Obtain satellite location Ground sweeping point at the moment of sweeping at 1 times ground speed and the satellite's position Actual ground push point at the start of stable ground velocity push sweep , The corresponding time is ; The calculation was obtained using the ground velocity push-broom control algorithm. and Calculate the corresponding desired attitude Euler angles. .

6. The method for planning satellite-to-ground missions with reduced ground velocity and push-sweep capability according to claim 5, characterized in that, Calculate the end time of the ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, including: Determine the end time of stable ground velocity push sweeping The satellite position corresponding to push-broom operation at 1x ground speed is Ground sweeping point is ; Obtain satellite location Actual ground push point at the end of the push sweep with reduced ground velocity , The corresponding time is ; The calculation was obtained using the ground velocity push-broom control algorithm. and Calculate the corresponding desired attitude Euler angles. .

7. The method for planning onboard missions with reduced ground velocity and push-sweep capability according to claim 6, characterized in that, Calculate the satellite's ground velocity push-broom start time and desired attitude Euler angles, including: Calculate the pitch rate during ground velocity stabilization push sweeping. and rolling angular velocity Through pitch angular velocity Interpolation to obtain the start time of the deceleration push sweep. ; Calculate the start time of ground velocity push sweeping ,Depend on , , Obtain the Euler angles of the desired pose .

8. A mission planning system for a satellite with reduced ground speed and push-sweep capability, characterized in that, include: The first calculation module is used to calculate the expected attitude Euler angles and the time when the push sweep reaches the geometric center of the survey area based on the spatial geometric relationship between the satellite, the ground target point and the Earth. The second calculation module is used to calculate the expected attitude quaternion from the inertial frame to the camera coordinate system, the expected attitude quaternion from the inertial frame to the satellite body frame, and the expected total attitude angular velocity of the satellite during the ground speed push-broom mode control algorithm without yaw angle correction when the satellite is pushed-broomed at ground speed. The current attitude quaternion and the current attitude angular velocity of the satellite are obtained from the satellite attitude determination. The third calculation module is used to calculate the start time of the satellite's ground velocity stabilization push-broom and the corresponding desired attitude Euler angles, as well as the end time of the ground velocity stabilization push-broom and the corresponding desired attitude Euler angles. The fourth calculation module is used to calculate the satellite's ground velocity push-broom start time and desired attitude Euler angles.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the on-board mission planning method for ground-speed push-broom satellite as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the on-board mission planning method for ground speed push-broom satellite as described in any one of claims 1 to 7.

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