Reverse push-broom multi-strip push-broom on-satellite task planning method and reverse push-broom multi-strip push-broom on-satellite task planning system

Abstract

The invention provides a reverse push-broom multi-strip push-broom on-satellite task planning method and system, and the method comprises the steps: firstly, setting an expected attitude pitch angle during the first forward push-broom, building a forward push-broom observation equation, solving a zero point of the observation equation through a Newton method, and obtaining an attitude pitch angle of the forward push-broom; the time from the first forward push-broom to the ground point of the geometric center of the surveying and mapping area and the expected attitude of the satellite can be obtained, the first push-broom task is completed, then the satellite attitude maneuver is performed to complete the reverse push-broom task, and the expected attitude pitch angle during the reverse push-broom is set. The time of reverse push-broom to the ground of the geometric center of the surveying and mapping area and the attitude of the satellite are calculated, after the reverse push-broom task is completed, the attitude of the satellite is maneuvered to the expected attitude of the second forward push-broom, then the third push-broom task can be completed, and the starting time and the ending time of the third push-broom task can be calculated.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite mission planning, and in particular to a mission planning method and system for a reverse push-broom multi-band push-broom satellite. Background Art

[0002] In traditional push-broom imaging, the satellite observes along the orbit. Due to the limitation of the camera width, a single shot cannot cover a large area. In order to increase the width of a single satellite image, strip stitching is required.

[0003] However, the traditional multi-strip splicing method usually completes one strip and adjusts the satellite's pitch angle to stabilize before conducting the next observation. This method affects the satellite's operating efficiency. Summary of the invention

[0004] The present invention provides a reverse push-broom multi-band push-broom satellite mission planning method and system, which are used to solve the defects existing in the prior art.

[0005] In a first aspect, the present invention provides a method for planning a mission on a multi-band push-sweep satellite with a reverse push-sweep, comprising: Calculate the time and expected Euler angle of the satellite's first forward push scan to the ground point at the geometric center of the survey area; Calculate the time, expected Euler angle and half push-scan time for the satellite to push back to the ground point at the geometric center of the survey area; Calculate the time and expected Euler angle of the satellite's second forward push scan to the ground point at the geometric center of the survey area; The reverse push-broom mode control algorithm is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-broom process, and the current attitude and current attitude angular velocity of the satellite during the push-broom process are obtained by attitude determination; Calculate the start and end times of the satellite's three push-scans.

[0006] According to a reverse push-sweep multi-band push-sweep satellite mission planning method provided by the present invention, the time and expected Euler angle of the satellite's first forward push-sweep to the ground point at the geometric center of the surveying area are calculated, including: Get the expected attitude pitch angle during the first forward push sweep , establish the geometric relationship between the satellite and the ground point of the geometric center of the surveying area; Establish the satellite observability condition equation ; Solving with Newton's method The zero point of the first forward push sweep is calculated to calculate the time for the first forward push sweep to the ground point at the geometric center of the survey area. ; By time Calculate the expected attitude Euler angles for the first forward push sweep .

[0007] According to a reverse push-sweep multi-band push-sweep satellite mission planning method provided by the present invention, the time for the satellite to reverse push-sweep to the ground point of the geometric center of the surveying area, the expected Euler angle and the half push-sweep time are calculated, including: Determine the satellite passing overhead during reverse push-scanning and establish the observable condition equation of the satellite during reverse push-scanning; The Newton method is used to solve the zero point of the observable condition equation of the satellite during reverse push scanning, and the time from reverse push scanning to the ground point of the geometric center of the surveying area is obtained. ; Depend on Calculate the expected attitude Euler angles of the reverse push scan to the ground point at the geometric center of the survey area ; Calculating half of the satellite push-sweep time using the satellite observable condition equation during reverse push-sweep .

[0008] According to a reverse push-sweep multi-band push-sweep satellite mission planning method provided by the present invention, the time and expected Euler angle of the satellite's second forward push-sweep to the ground point at the geometric center of the surveying area are calculated, including: The expected attitude pitch angle during the second forward push sweep is obtained as , establish the geometric relationship between the satellite and the ground point of the geometric center of the surveying area; Establish the satellite observability condition equation ; Solving with Newton's method The time for the second forward push sweep to the ground point at the geometric center of the survey area is calculated. ; By time Calculate the expected attitude Euler angles for the second forward push sweep .

[0009] According to a reverse push-broom multi-band push-broom satellite mission planning method provided by the present invention, a reverse push-broom mode control algorithm is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-broom process, and the current attitude and current attitude angular velocity of the satellite during the push-broom process are obtained by attitude determination, including: The expected attitude quaternion from the inertial system to the camera coordinate system without drift angle correction during satellite reverse push scanning is: ; Calculate the expected attitude quaternion from the inertial system to the satellite system: ; Calculate the expected total angular velocity of the satellite during reverse push-scanning ; Obtain the satellite's current attitude quaternion and the satellite's current attitude angular velocity .

[0010] According to a reverse push-broom multi-band push-broom satellite mission planning method provided by the present invention, the expected attitude quaternion from the inertial system to the satellite system is calculated as ,include: According to the dynamic link library of the deviation angle calculation, it is obtained :

[0011] The expected attitude quaternion from the orbit system to the camera coordinate system is:

[0012] Then the desired attitude quaternion from the inertial system to the camera coordinate system is , the attitude quaternion from the satellite system to the corresponding camera coordinate system is , then the expected attitude quaternion from the inertial system to the satellite system is .

[0013] According to a multi-band push-sweep satellite mission planning method for reverse push-sweep provided by the present invention, the expected total angular velocity of the satellite attitude during reverse push-sweep is calculated. ,include: Determine that the attitude angle rotation sequence including the drift angle correction is 3213, the c-axis is the camera coordinate system, and the b-axis is the satellite body coordinate system; The yaw angle of the first rotation around the Zc axis , , the second rotation around the Yc axis, the pitch angular velocity Push sweep, and They are the desired attitude pitch angle of the current and previous control cycles, the third rotation around the Xc axis, and the roll angle Push sweep, and are the expected attitude roll angles of the current and previous control cycles, the fourth rotation around the Zb axis for drift angle correction, and the yaw angular velocity It can be obtained from the drift angle calculation dynamic link library, and the satellite's relative orbital angular velocity is projected in the camera coordinate system as:

[0014] 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 in the body coordinate system is:

[0015] The angular velocity of the orbital system is Projected to the satellite coordinate system:

[0016] is the satellite's ground speed ratio; The expected total angular velocity of the satellite is obtained as: .

[0017] According to a reverse push-sweep multi-band push-sweep satellite mission planning method provided by the present invention, the start time and the end time of three push-sweeps of the satellite are calculated, including: Calculate the start time of the first forward push sweep And the first sweep end time ; Calculate the time for reverse push-sweep to start stable push-sweep And the end time of reverse push sweep ; Calculate the start time of the third push sweep And find the end time of the third push sweep ; calculate ,like , then The value of Then restart the calculation.

[0018] In a second aspect, the present invention further provides a reverse push-sweep multi-band push-sweep satellite mission planning system, comprising: The first calculation module is used to calculate the time and expected Euler angle of the satellite's first forward push sweep to the ground point at the geometric center of the surveying and mapping area; The second calculation module is used to calculate the time, expected Euler angle and half push-scan time for the satellite to push back to the ground point of the geometric center of the surveying area; The third calculation module is used to calculate the time and expected Euler angle of the satellite's second forward push sweep to the ground point at the geometric center of the surveying and mapping area; A fourth calculation module is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-scan process by using a reverse push-scan mode control algorithm, and obtain the current attitude and current attitude angular velocity of the satellite during the push-scan process by attitude determination; The fifth calculation module is used to calculate the start time and end time of three push-scans of the satellite.

[0019] In a third aspect, the present invention further provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, a method for planning a mission on a multi-band push-scan satellite for reverse push-scanning as described in any one of the above-mentioned methods is implemented.

[0020] The reverse push-scan multi-strip push-scan satellite mission planning method and system provided by the present invention, after the first strip is photographed, the second strip is imaged directly in the retracement process. This strategy significantly reduces the maneuvering time and improves the strip splicing efficiency, thereby achieving effective coverage of multiple strips in one mission. Compared with the traditional multi-strip forward push method, the reverse push-scan technology utilizes the flexibility of satellite attitude maneuvers and can perform multi-strip observations more efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic flow chart of a task planning method on a multi-band push-sweep satellite for reverse push-sweep provided by the present invention; Figure 2 It is a schematic diagram of the geometric relationship of the stereoscopic surveying and mapping space provided by the present invention; Figure 3 Schematic diagram of total pointing deviation in the first ground push-scan mode provided by the present invention; Figure 4 It is a schematic diagram of the satellite X-axis angular velocity deviation in the first earth push-scan mode provided by the present invention; Figure 5 It is a schematic diagram of the satellite Y-axis angular velocity deviation in the first earth push-scan mode provided by the present invention; Figure 6 It is a schematic diagram of the satellite Z-axis angular velocity deviation in the first ground push-scan mode provided by the present invention; Figure 7 Schematic diagram of total pointing deviation in the reverse push-scan mode provided by the present invention; Figure 8 It is a schematic diagram of the satellite X-axis angular velocity deviation in the reverse push-scan mode provided by the present invention; Fig. 9 It is a schematic diagram of the satellite Y-axis angular velocity deviation in the reverse push-scan mode provided by the present invention; Fig.10 It is a schematic diagram of the satellite Z-axis angular velocity deviation in the reverse push-scan mode provided by the present invention; Fig.11 Schematic diagram of total pointing deviation in the second ground push-scan mode provided by the present invention; Fig.12 It is a schematic diagram of the satellite X-axis angular velocity deviation in the second earth push-scan mode provided by the present invention; Fig.13 It is a schematic diagram of the satellite Y-axis angular velocity deviation in the second earth push-scan mode provided by the present invention; Fig.14 It is a schematic diagram of the satellite Z-axis angular velocity deviation in the second earth push-scan mode provided by the present invention; Fig.15 It is a schematic diagram of the structure of the mission planning system on a multi-band push-sweep satellite of the reverse push-sweep provided by the present invention; Fig.16 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. 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.

[0024] In view of the shortcomings of the prior art, the present invention proposes a multi-strip push-scan satellite mission planning method including reverse push-scanning. After the first strip is shot, the second strip is imaged directly during the retracement process, thereby reducing the maneuvering time and improving the strip splicing efficiency, thereby achieving effective coverage of multiple strips in one mission.

[0025] To achieve the above objectives, the Euler angles involved in the technical solution provided by the present invention are all in 321 order. Figure 1 FIG. 1 is a flow chart of a method for planning a task on a multi-band push-sweep satellite for reverse push-sweep according to an embodiment of the present invention. Figure 1 As shown, including: Step 100: Calculate the time and expected Euler angle of the satellite's first forward push scan to the ground point at the geometric center of the surveying area; Step 200: Calculate the time, expected Euler angle and half push-scan time for the satellite to push back to the ground point at the geometric center of the surveying area; Step 300: Calculate the time and expected Euler angle of the satellite's second forward push sweep to the ground point at the geometric center of the surveying area; Step 400: using a reverse push-broom mode control algorithm to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-broom process, and obtaining the current attitude and current attitude angular velocity of the satellite during the push-broom process based on the attitude determination; Step 500: Calculate the start time and end time of three push-scans of the satellite.

[0026] The embodiment of the present invention first sets the expected attitude pitch angle during the first forward push-sweep to establish the observation equation of the forward push-sweep, and uses Newton's method to obtain the zero point of the observation equation, so as to obtain the time when the first forward push-sweep reaches the ground point at the geometric center of the surveying area and the expected attitude of the satellite, thereby completing the first push-sweep task, and then maneuvers the satellite attitude to complete the reverse push-sweep task. By setting the expected attitude pitch angle during the reverse push-sweep, the time when the reverse push-sweep reaches the ground point at the geometric center of the surveying area and the attitude of the satellite are calculated. After completing the reverse push-sweep task, the satellite attitude maneuvers to the expected attitude during the second forward push-sweep, thereby completing the third push-sweep task, and calculating the start and end times of the three push-sweep tasks.

[0027] Specifically, the steps include: Step 1: Calculate the time of the first forward push scan to the ground point at the geometric center of the survey area and the expected Euler angle of the satellite.

[0028] Step 1.1, such as Figure 2 , the expected attitude pitch angle during the first forward push sweep is , establish the geometric relationship between the satellite and the ground point of the geometric center of the surveying area; Record the satellite push scan to the ground point of the geometric center of the survey area T When the ground point T The geocentric vector is denoted as ,satellite S The geocentric vector is denoted as , the speed is recorded as , then the radius vector of the ground point relative to the satellite is (1) To make the center of the camera lens point to the ground point, there should be (2) is the satellite orbital angular momentum The unit vector is calculated as follows (3) Yaw angle , then the satellite attitude corresponds to The axis points to (4) Set the pitch angle for forward sweep , the expected attitude pitch angle during the first forward push sweep is ,but Axis and satellite's geocentric radius Angle of the radius vector , and the satellite-target line does not pass through the earth, there is (5) Step 1.2, establish the satellite observability condition equation.

[0029] Ignoring the constraint that the satellite-target line does not pass through the earth, the observation function constructed based on formula (2) is: (6) Using the vector triple product to expand the Lagrange formula, we have

[0030] Substituting in: (7) Step 1.3, use Newton's method to find the zero point of the observation equation in step 1.2, and calculate the time of the first forward push sweep to the ground point at the geometric center of the survey area The specific implementation process is as follows: Let the observation equation in step 1.2 be When , the target is at the critical position of the satellite's visible range.

[0031] Finding functions using Newton's method The zero point of the target is determined to determine the start and end time of the target. Newton's solution has Convergence speed: When the initial value is designed reasonably, it has a faster convergence speed, and the implementation method is as follows.

[0032] Assume that the initial value of the solution is , in each iteration, (8) when and The difference is less than a small amount When , the solution process converges to is the numerical solution of the equation and the iteration ends.

[0033] If the number of iterations is greater than a certain upper limit If it still does not converge, the initial value is considered unreliable. It cannot be designed to be too large, otherwise there is a possibility of converging to the zero point in other visible segments. Considering the fast convergence characteristics of the Newton iteration method, in the embodiment of the present invention, .

[0034] Initial Value The screening is as follows, based on the first orbital period (in for The latitude of the satellite when it enters and exits the quasi-visible segment within the orbital period (the starting point of the orbital period) is calculated to obtain the true anomaly estimate when entering and exiting the quasi-visible segment. The argument of perigee is used to replace the argument of perigee at any time in the period, and the true anomaly is used to calculate the true anomaly estimate when entering and exiting the quasi-visible segment. and the angle of approach The relationship between the angle of approach and and time The relationship between them can be used to determine the time of entering and exiting the quasi-visible segment.

[0035] According to the satellite's geocentric longitude during the ascending and descending orbits (different for prograde and retrograde orbits), combined with , , , and the time of entering and exiting the quasi-visible segment, and They represent the upper and lower limits of the satellite’s geocentric longitude during the orbit raising phase. and The upper and lower limits of the satellite's geocentric longitude during the descending phase are obtained to obtain the sub-satellite point longitude when entering and leaving the quasi-visible phase, that is, , , and , and They represent the upper and lower limits of the longitude of the lower point of the satellite when entering the quasi-visible period. and They represent the upper and lower limits of the longitude of the lower point of the star when exiting the quasi-visible period. The value range is limited to .

[0036] Considering the longitude From the jump to The possibility of , if (direct and retrograde orbits are different) (9) Then the corresponding and As a set of feasible initial values, substitute them into equation (8) and solve them.

[0037] Similarly, if (the direct and retrograde orbits are different) (10) Then the corresponding and As a set of feasible initial values, substitute them into equation (8) and solve them.

[0038] Otherwise, The orbital period does not have The possibility of making observations does not participate in the solution.

[0039] This screening can also avoid The unreasonableness.

[0040] Finally, the initial value is substituted into the observation equation Solve time .

[0041] Step 1.4: The time in step 1.3 Calculate the expected attitude Euler angles for the first forward push sweep The specific process is as follows: Obtain the time it takes for the satellite to push forward to the ground point at the geometric center of the survey area Then, the position of the target in the inertial system can be obtained. ,speed , and the position of the satellite in the inertial frame ,speed .

[0042] Yaw angle , then the satellite's expected attitude corresponds to The axis points to

[0043] Then the satellite's expected attitude coordinate system is

[0044] The satellite's current orbital coordinate system is

[0045] The transformation matrix from the inertial system to the satellite's desired attitude coordinate system is:

[0046] The transformation matrix from the inertial system to the satellite's current orbital coordinate system is:

[0047] The transformation matrix from the satellite's current orbital coordinate system to the satellite's expected attitude coordinate system is:

[0048] Define the Euler angles of the 321 transition (yaw, pitch, roll), the attitude matrix is

[0049] When the satellite pushes to the ground point at the geometric center of the survey area, the required rolling angle is

[0050] The expected Euler angle of the satellite's first forward push sweep is . Due to the maximum rolling angle during stereo mapping, . The solutions that do not meet this condition need to be discarded.

[0051] Step 2: Calculate the time for reverse push-scanning to the ground point at the geometric center of the survey area, the expected Euler angle of the satellite, and half the push-scanning time.

[0052] Step 2.1: When the satellite passes overhead during reverse push-scanning, establish the observable condition equation of the satellite during reverse push-scanning. The specific process is as follows: According to step 1.1, due to the pitch angle during stable push sweep ,but Axis and satellite's geocentric radius Angle of the radius vector ,have (11) The constructed observation function is: (12) have (13) right To perform the derivation: (14) The visibility function and its derivatives can be calculated.

[0053] Step 2.2, same as step 1.3, using Newton's method to find the function The zero point of the survey area is selected to find the time for reverse push scanning to the ground point of the geometric center of the survey area. .

[0054] Step 2.3, the time in step 2.2 Calculate the expected attitude Euler angle of the reverse push scan to the ground point at the geometric center of the survey area: , the specific solution process is the same as step 1.4; Step 2.4, use the observation equation in step 2.1 to calculate the half push-scan time of the satellite , the specific process is as follows; The maximum time of stable push sweep in reverse direction ,in is the attitude maneuvering time required for the satellite to switch from the first forward push-sweep to the reverse push-sweep, and the start time of the reverse push-sweep stable push-sweep is , the first forward push-broom to reverse push-broom attitude maneuver start time .

[0055] Maneuvering time from the first forward push-sweep to the reverse push-sweep attitude After that, the initial attitude pitch angle when the reverse push sweep starts to stabilize the push sweep , the Euler angle of this posture is The time from sweeping to the ground point at the geometric center of the sweeping area in this attitude is , It can be obtained from the observation equation in step 2.1. At this time, the distance from the ground point where the reverse push-broom starts to be stable is about half the total push-broom length, which is equivalent to the time difference , then the stable push sweep time , since this estimate has a certain deviation, it is advisable to .

[0056] Step 3, calculating the time of the second forward push scan to the ground point at the geometric center of the surveying area and the expected Euler angle of the satellite; Step 3.1, the desired attitude pitch angle during the second forward sweep is , the geometric relationship between the satellite and the ground point at the geometric center of the survey area is established. This is the same as the first forward push-scan process in step 1.1, and will not be repeated here; Step 3.2, the observable condition equation of the satellite is established, which is the same as the observation equation obtained by the first forward push sweep in step 1.2, and will not be repeated here; Step 3.3, use Newton's method to find the zero point of the observation equation in step 3.2, and calculate the time for the second forward push sweep to the ground point at the geometric center of the survey area. The solution process here is the same as in step 1.3, so I will not repeat it here. Step 3.4: The time in step 3.3 Calculate the expected attitude Euler angles for the second forward push sweep The solution process here is the same as in step 1.4. Finally, the expected attitude Euler angle during the second forward push sweep is .

[0057] Step 4: The specific process of the reverse push-sweep mode control algorithm is as follows; Step 4.1, calculate the expected attitude quaternion from the inertial system to the camera coordinate system without drift angle correction during satellite reverse push scanning: , as follows: This mode is to make the whole satellite perform attitude maneuvers at a certain pitch angle speed within a certain time range, so that the payload optical axis can be pushed and scanned in the reverse track direction at a constant ground speed. Shaft installation, so according to The axis points to the ground point to design the control law, and the spatial geometric relationship is as follows Figure 3 Satellite S The geocentric vector is denoted as , the speed is recorded as , the current subsatellite point is , the center of the earth is .

[0058] The starting point of the satellite reverse push scan is , the starting time is The satellite reverse push sweep trajectory is parallel to the forward push sweep trajectory, and the roll angle is not a constant value during reverse push sweep. Using the 321 sequence, the satellite roll angle is also constantly adjusted during the pitch direction push sweep. After determining the pointing attitude, the drift angle needs to be corrected around the Zb axis.

[0059] According to the task planning procedure, we can get the 321 transfer sequence The initial expected posture Euler angle at time is , The Euler angle of the posture at the moment is .

[0060] Satellite from Starting from the moment, at a constant pitch angular velocity Reverse push sweep, The expected elevation angle of the satellite at time , expected roll angle Obtained by interpolation. 321 The expected Euler angle under the order of rotation , the corresponding expected attitude quaternion from the orbit system to the camera coordinate system without the drift angle correction is .

[0061] Step 4.2, calculate the expected attitude quaternion from the inertial system to the satellite system: , as follows: First, the posture obtained in step 4.1 needs to be corrected for the drift angle. According to the drift angle calculation dynamic link library, we can get .

[0062]

[0063] The desired attitude quaternion from the orbital system to the camera coordinate system is

[0064] Then the desired attitude quaternion from the inertial system to the camera coordinate system is Since the attitude quaternion from the satellite system to the corresponding camera coordinate system is , then the expected attitude quaternion from the inertial system to the satellite system is .

[0065] Step 4.3, calculate the expected total angular velocity of the satellite during reverse push scanning , as follows: First, solve the relative angular velocity with respect to the orbital system. Since the attitude angle rotation sequence including the drift angle correction is 3213, the yaw angle of the first rotation around the Zc axis is , ; The second rotation around the Yc axis, at a constant pitch angular velocity Push sweep; third rotation around the Xc axis, roll angle By interpolation, we obtain Also obtained by interpolation; the fourth rotation around the Zb axis is used to correct the drift angle, and the yaw angular velocity It can be obtained from the dynamic link library for calculating the drift angle. 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.

[0066] The projection of the satellite's angular velocity relative to the orbital system in the body coordinate system is: .

[0067] On the other hand, the angular velocity of the orbital system is , projecting it to the satellite coordinate system

[0068] The expected total angular velocity of the satellite is

[0069] Step 4.4, obtain the satellite's current attitude quaternion and the satellite's current attitude angular velocity ; Satellite current attitude quaternion Obtained by attitude determination, the satellite's current attitude angular velocity Obtained by posture determination.

[0070] Step 5, calculate the start time and end time of three push scans.

[0071] Step 5.1, calculate the start time of the first forward push sweep And the first sweep end time , the first forward push sweep start time , start imaging time , the end time of the first push sweep is the start time of the first attitude maneuver .

[0072] Step 5.2, calculate the time for the reverse push-sweep to start stable push-sweep And the end time of reverse push sweep ; When the reverse push sweep starts to be stable, the ground point to be swept is At this moment, the satellite is in the attitude The ground point pointed to, and , , , its position relative to the ground can be obtained as .

[0073] Reverse push sweep starts stable push sweep moment , and the satellite's attitude Euler angle pointing to this ground point The roll angle of the Euler angle of the desired attitude from the beginning of the reverse push sweep to the top pass is obtained by interpolation ,and , otherwise Then restart the calculation from step 5.1.

[0074] When the reverse sweep ends, the ground point to be swept is At this moment, the satellite is in the attitude The ground point pointed to, and , , , its position relative to the ground can be obtained as .

[0075] Then find the end time of reverse sweep , and the satellite's attitude Euler angle pointing to this ground point and The roll angle of the Euler angle of the desired attitude from the top to the end of the push sweep is obtained by interpolation ,and , otherwise Then restart the calculation from step 5.1.

[0076] In summary, the time for reverse push-sweep to start stable push-sweep , reverse push sweep end time .

[0077] Step 5.3, calculate the start time of the third push sweep And find the end time of the third push sweep ; The third push sweep starts at , the third sweep end time .

[0078] Step 5.4, calculate ,if , then the above The value of Then restart the calculation from step 5.1.

[0079] Based on the above embodiment, in order to verify the effectiveness of the present invention in the reverse push-sweep mission planning of an agile remote sensing optical satellite, the parameters of the satellite on-orbit test are: 1. Target parameters Longitude: -9.13° Latitude: 38.79° Height: 157.318m Reverse push sweep forward pitch angle: 25° Sun altitude angle: 63° 2. Command parameters First push sweep start time: 487510331s Expected Euler angles for the first push sweep: yaw 0°; pitch 25°; roll -4.176240753563° First push sweep duration: 19.787s Expected Euler angles for the second push sweep: yaw 0°; pitch 35°; roll -6.126368152670° Reverse push sweep pitch speed: 1.5° / s Reverse stable push sweep start time: 487510367s Reverse stable push sweep overhead time: 487510374 Reverse push sweep end time: 487510382s The side swing angle at the start of the reverse stable push sweep is -4.88961614° Reverse stable push sweep over the top of the side swing angle: -4.40630024° The side swing angle at the end of the reverse stable push sweep is -3.73244541° The third push sweep started at: 487510402s Expected Euler angles for the third push sweep: yaw 0°; pitch -25°; roll -3.737005946494° The third sweep duration: 15.649s According to the above parameters, the satellite was tested on-orbit, the reverse push-broom planning and control method was simulated, and the three strips of data were analyzed, where strips 1 and 3 were for ground push-broom and strip 2 was for reverse push-broom. The results are as follows: The expected Euler angles for strip 1 are (0, 25, -4.1762)°, such as Figures 3 to 6 As shown, the total pointing deviation during the ground push scan is 0.01045° (3σ), the X-axis attitude stability is 0.00081° / s (3σ), the Y-axis attitude stability is 0.00082° / s (3σ), and the Z-axis attitude stability is 0.00070° / s (3σ).

[0080] Strip 2 is reverse push sweep, such as Figures 7 to 10 As shown, the total pointing deviation is 0.12° (3σ), the X-axis attitude stability is 0.0011° / s (3σ), the Y-axis attitude stability is 0.004° / s (3σ), and the Z-axis attitude stability is 0.006° / s (3σ).

[0081] The expected Euler angles of strip 3 are (0, -25, -3.737)°, and the attitude converges after 21 seconds of maneuvering. Figures 11 to 14 As shown in the figure, the total pointing deviation during the ground scan is 0.027° (3σ), the X-axis attitude stability is 0.0007° / s (3σ), the Y-axis attitude stability is 0.0006° / s (3σ), and the Z-axis attitude stability is 0.002° / s (3σ).

[0082] Above Figures 3 to 14 The simulation results verify that the reverse push-scan imaging planning and control method for remote sensing satellites proposed in the present invention can achieve rapid dynamic response and stable adjustment during the satellite attitude control process, meet the imaging accuracy requirements, and ensure the smooth completion of on-orbit missions.

[0083] The reverse push-sweep multi-band push-sweep satellite mission planning system provided by the present invention is described below. The reverse push-sweep multi-band push-sweep satellite mission planning system described below and the reverse push-sweep multi-band push-sweep satellite mission planning method described above can correspond to each other.

[0084] Fig.15 FIG. 1 is a schematic diagram of a task planning system for a multi-band push-sweep satellite with reverse push-sweep provided by the present invention. Fig.15 As shown, it includes: a first calculation module 1501, a second calculation module 1502, a third calculation module 1503, a fourth calculation module 1504 and a fifth calculation module 1505, wherein: The first calculation module 1501 is used to calculate the time and expected Euler angle of the satellite's first forward push-sweep to the ground point at the geometric center of the surveying and mapping area; the second calculation module 1502 is used to calculate the time, expected Euler angle and half push-sweep time of the satellite's reverse push-sweep to the ground point at the geometric center of the surveying and mapping area; the third calculation module 1503 is used to calculate the time and expected Euler angle of the satellite's second forward push-sweep to the ground point at the geometric center of the surveying and mapping area; the fourth calculation module 1504 is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-sweep process using the reverse push-sweep mode control algorithm, and obtain the current attitude and current attitude angular velocity of the satellite during the push-sweep process based on the attitude; the fifth calculation module 1505 is used to calculate the start time and end time of the satellite's three push-sweeps.

[0085] Fig.16 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.16As shown, the electronic device may include: a processor 1610, a communication interface 1620, a memory 1630 and a communication bus 1640, wherein the processor 1610, the communication interface 1620 and the memory 1630 communicate with each other through the communication bus 1640. The processor 1610 may call the logic instructions in the memory 1630 to execute the reverse push sweep multi-band push sweep satellite mission planning method, the method comprising: calculating the time and expected Euler angle of the satellite's first forward push sweep to the ground point at the geometric center of the surveying area; calculating the time, expected Euler angle and half push sweep time of the satellite's reverse push sweep to the ground point at the geometric center of the surveying area; calculating the time and expected Euler angle of the satellite's second forward push sweep to the ground point at the geometric center of the surveying area; using the reverse push sweep mode control algorithm to calculate the expected attitude and expected attitude angular velocity of the satellite during the push sweep process, and obtaining the current attitude and current attitude angular velocity of the satellite during the push sweep process by the attitude determination; calculating the start time and end time of the satellite's three push sweeps.

[0086] In addition, the logic instructions in the above-mentioned memory 1630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, 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, and the computer software product is stored in a storage medium, including a number of 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 method 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 and other media that can store program codes.

[0087] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0088] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for planning a mission on a multi-band push-sweep satellite with reverse push-sweep, characterized in that: include: Calculate the time and expected Euler angle of the satellite's first forward push scan to the ground point at the geometric center of the survey area; Calculate the time, expected Euler angle and half push-scan time for the satellite to push back to the ground point at the geometric center of the survey area; Calculate the time and expected Euler angle of the satellite's second forward push scan to the ground point at the geometric center of the survey area; The reverse push-broom mode control algorithm is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-broom process, and the current attitude and current attitude angular velocity of the satellite during the push-broom process are obtained by attitude determination; Calculate the start and end times of the satellite's three push-scans.

2. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 1, characterized in that: Calculate the time and expected Euler angle of the satellite's first forward push sweep to the ground point at the geometric center of the survey area, including: Get the expected attitude pitch angle during the first forward push sweep , establish the geometric relationship between the satellite and the ground point of the geometric center of the surveying area; Establish the satellite observability condition equation ; Solving with Newton's method The zero point of the first forward push sweep is calculated to calculate the time when the first forward push sweep reaches the ground point at the geometric center of the survey area. ; By time Calculate the expected attitude Euler angles for the first forward push sweep .

3. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 1, characterized in that: Calculate the time, expected Euler angle and half push-scan time for the satellite to push back to the ground point at the geometric center of the survey area, including: Determine the satellite passing overhead during reverse push-scanning and establish the observable condition equation of the satellite during reverse push-scanning; The Newton method is used to solve the zero point of the observable condition equation of the satellite during reverse push scanning, and the time from reverse push scanning to the ground point of the geometric center of the surveying area is obtained. ; Depend on Calculate the expected attitude Euler angles of the reverse push scan to the ground point at the geometric center of the survey area ; Calculating half of the satellite push-sweep time using the satellite observable condition equation during reverse push-sweep .

4. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 1, characterized in that: Calculate the time and expected Euler angle of the satellite's second forward push sweep to the ground point at the geometric center of the survey area, including: The expected attitude pitch angle during the second forward push sweep is obtained as , establish the geometric relationship between the satellite and the ground point of the geometric center of the surveying area; Establish the satellite observability condition equation ; Solving with Newton's method The time for the second forward push sweep to the ground point at the geometric center of the survey area is calculated. ; By time Calculate the expected attitude Euler angles for the second forward push sweep .

5. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 1, characterized in that: The reverse push-broom mode control algorithm is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-broom process, and the current attitude and current attitude angular velocity of the satellite during the push-broom process are obtained by attitude determination, including: The expected attitude quaternion from the inertial system to the camera coordinate system without drift angle correction during satellite reverse push scanning is: ; Calculate the expected attitude quaternion from the inertial system to the satellite system: ; Calculate the expected total angular velocity of the satellite during reverse push-scanning ; Obtain the satellite's current attitude quaternion and the satellite's current attitude angular velocity .

6. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 5, characterized in that: Calculate the expected attitude quaternion from the inertial system to the satellite system: ,include: According to the dynamic link library of the deviation angle calculation, it is obtained : The expected attitude quaternion from the orbit system to the camera coordinate system is: Then the desired attitude quaternion from the inertial system to the camera coordinate system is , the attitude quaternion from the satellite system to the corresponding camera coordinate system is , then the expected attitude quaternion from the inertial system to the satellite system is .

7. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 5, characterized in that: Calculate the expected total angular velocity of the satellite during reverse push-scanning ,include: Determine that the attitude angle rotation sequence including the drift angle correction is 3213, the c-axis is the camera coordinate system, and the b-axis is the satellite body coordinate system; The yaw angle of the first rotation around the Zc axis , , the second rotation around the Yc axis, the pitch angular velocity Push sweep, and They are the desired attitude pitch angle of the current and previous control cycles, the third rotation around the Xc axis, and the roll angle Push sweep, and are the expected attitude roll angles of the current and previous control cycles, the fourth rotation around the Zb axis for drift angle correction, and the yaw angular velocity It can be obtained from the drift angle calculation dynamic link library, and the satellite's relative orbital angular velocity is projected in the camera coordinate system as: 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 in the body coordinate system is: The angular velocity of the orbital system is Projected to the satellite coordinate system: is the satellite's ground speed ratio; The expected total angular velocity of the satellite is obtained as: 。 8. The method for planning a mission on a multi-band push-sweep satellite for reverse push-sweep according to claim 1, characterized in that: Calculate the start and end time of the satellite's three push-scans, including: Calculate the start time of the first forward push sweep And the first sweep end time ; Calculate the time for reverse push-sweep to start stable push-sweep And the end time of reverse push sweep ; Calculate the start time of the third push sweep And find the end time of the third push sweep ; calculate ,like , then The value of Then restart the calculation.

9. A multi-band push-sweep mission planning system for a reverse push-sweep satellite, characterized in that: include: The first calculation module is used to calculate the time and expected Euler angle of the satellite's first forward push sweep to the ground point at the geometric center of the surveying and mapping area; The second calculation module is used to calculate the time, expected Euler angle and half push-scan time for the satellite to push back to the ground point of the geometric center of the surveying area; The third calculation module is used to calculate the time and expected Euler angle of the satellite's second forward push sweep to the ground point at the geometric center of the surveying and mapping area; A fourth calculation module is used to calculate the expected attitude and expected attitude angular velocity of the satellite during the push-scan process by using a reverse push-scan mode control algorithm, and obtain the current attitude and current attitude angular velocity of the satellite during the push-scan process by attitude determination; The fifth calculation module is used to calculate the start time and end time of three push-scans of the satellite.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the method for planning a mission on a multi-band push-sweep satellite according to any one of claims 1 to 8 is implemented.

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