High-precision inter-satellite pointing control method fused with laser interferometry

Abstract

The invention provides a high-precision inter-satellite pointing control method fusing laser interference measurement, and relates to the field of spacecraft control. The method comprises the following steps: firstly, carrying out validity judgment and processing on an attitude error value provided by the measurement of the laser interferometer in the period, carrying out attitude angular velocity differential calculation, and when the attitude error value provided by the measurement of the laser interferometer in the period is valid, carrying out reference error calculation in combination with an attitude error value provided by orbit extrapolation and on-satellite attitude determination; then, according to attitude error value validity provided by measurement of the laser interferometer in the current period and the last period, on the basis of a reference introduction / direct introduction selection mark set on the ground, determining to implement reference introduction calculation or direct introduction calculation, calculating an attitude control quantity and an angular velocity control quantity, and finally, according to the attitude control quantity and the angular velocity control quantity, calculating the attitude control quantity and the angular velocity control quantity. An attitude control moment is calculated by using a control law and is implemented by an execution mechanism. According to the invention, high-precision pointing error measurement of the laser interferometer is introduced, so that high-precision inter-satellite pointing control of satellites is realized.

Description

Technical Field

[0001] This invention relates to the field of spacecraft control, and in particular to a high-precision inter-satellite pointing control method that integrates laser interferometry, applicable to all spacecraft that require the introduction of laser interferometer measurements for attitude control. Background Technology

[0002] For formation satellites using laser interferometers for inter-satellite ranging, the requirements for inter-satellite pointing control accuracy are very high to meet the needs of mutual acquisition under extremely narrow laser interferometer beam conditions and to ensure stable and continuous tracking after acquisition. Existing technology achieves inter-satellite pointing control for laser interferometer operation by calculating the inter-satellite pointing angle through high-precision orbit extrapolation of the two satellites and controlling the satellites to track this angle. However, due to limitations in orbit extrapolation accuracy, the inter-satellite pointing control accuracy is difficult to improve, and stable and continuous tracking by the laser interferometer cannot be guaranteed. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a high-precision inter-satellite pointing control method that integrates laser interferometry. By introducing high-precision pointing error measurement of laser interferometer, high-precision inter-satellite pointing control of satellites is realized.

[0004] The technical solution of this invention is: a high-precision inter-satellite pointing control method integrating laser interferometry, wherein an inter-satellite pointing attitude is established during satellite flight, that is, the X-axis of two satellites are aligned with each other pointing towards the position of the other satellite; both satellites are equipped with laser interferometers, and the laser interferometers are coaxial with the X-axis of their respective satellites; the method includes: Based on the attitude error value provided by the laser interferometer measurement in the previous cycle, the validity of the attitude error value provided by the laser interferometer measurement in the current cycle is judged and processed, and the attitude angular velocity difference is calculated. When the attitude error value provided by the laser interferometer measurement in this cycle is valid, the reference error is calculated by combining the attitude error value provided by orbit extrapolation and on-board attitude determination. Based on the validity judgment results of the attitude error values ​​provided by the laser interferometer measurements in the current and previous cycles, and based on the reference introduction / direct introduction selection flag set on the ground, it is determined whether to implement reference introduction calculation or direct introduction calculation; when implementing direct introduction calculation, the attitude control quantity and angular velocity control quantity are calculated based on the attitude error value provided by the laser interferometer measurement and the attitude angular velocity difference calculation result; when implementing reference introduction calculation, the attitude control quantity and angular velocity control quantity are calculated based on the attitude error value provided by orbit extrapolation and the reference error calculation result. Finally, based on the attitude control quantity and angular velocity control quantity, the attitude control torque is calculated using the control law and implemented by the actuator.

[0005] Preferably, the validity judgment includes: like or or or ,or N consecutive times or If the measurement is repeated N times consecutively, the valid laser interferometer measurement flag F_LaserValid for this cycle is set to 0; otherwise, F_LaserValid is set to 1. in, , These are the yaw attitude error values ​​and pitch attitude error values ​​provided by the laser interferometer measurements during this cycle, respectively. , These are the yaw attitude error values ​​and pitch attitude error values ​​provided by the laser interferometer measurements in the previous cycle, respectively. and These are the yaw error threshold and the pitch error threshold, respectively. To control the cycle length, and These are the threshold values ​​for yaw error variation and pitch error variation, respectively. and These are the yaw constant threshold and pitch constant threshold, respectively. Nmin is the threshold for the number of attitude error constants. F_LaserValid is 1 for valid and 0 for invalid.

[0006] Preferably, Nmin is 5 to 20; and Set the values ​​by subtracting K1 from the effective ranges of the yaw attitude error and pitch attitude error provided by the laser interferometer, respectively. and The settings are calculated by multiplying the satellite's yaw rate error index and pitch rate error index (when using a laser interferometer) by the control period length and then adding K2. and The settings are determined by multiplying the attitude noise index measured by the laser interferometer by K3; K1 is 0.01º~0.1º, K2 is 0.001º~0.1º, and K3 is 0.1~0.9.

[0007] Preferably, the yaw attitude error value is provided by combining on-board orbit extrapolation and attitude determination. pitch attitude error value Calculate the yaw reference error and pitch reference error : , , In the formula, and Yaw reference error and pitch reference error The calculated value of the previous period, The reference error filtering coefficient is set to a value between 0.02 and 0.2.

[0008] Preferably, the method for determining whether to perform a reference-introduced calculation or a direct-introduced calculation is as follows: The ground-based reference introduction / direct introduction selection flag FP_LaserGuide is set to 0 to indicate reference introduction and 1 to indicate direct introduction. When FP_LaserGuide is 1, and the validity of the attitude error value provided by the laser interferometer measurement in the current cycle (F_LaserValid) and the validity of the attitude error value provided by the laser interferometer measurement in the previous cycle (F_LaserValidlst) are both 1, then the introduction calculation mode flag F_LaserGuide is determined to be 1, indicating that direct introduction calculation is performed. Otherwise, when at least one of FP_LaserGuide, F_LaserValid, and F_LaserValidlst is 0, the introduction calculation mode flag F_LaserGuide is determined to be 0, indicating that reference introduction calculation is performed.

[0009] Preferably, when implementing reference-introduction calculations, the roll, pitch, and yaw three-axis attitude control quantities are... , , and three-axis angular velocity control quantity , , The calculation is as follows: , , , , ,

[0010] , The yaw and pitch attitude error angles provided for orbit extrapolation and attitude determination, respectively, are for orbit extrapolation and attitude determination. , These are the yaw reference error and the pitch reference error, respectively. For satellite real-time roll angle, , , It provides the real-time roll, pitch, and yaw attitude angular velocities of the satellite.

[0011] Preferably, the yaw and pitch attitude error angles provided by the on-board orbit extrapolation and attitude determination are determined through real-time online prediction in orbit. Specific steps include: The ground generates a sequence of binary satellite orbital position and velocity values ​​for a predetermined time period and samples them according to the control cycle. For each sampling moment, the local satellite orbital coordinate system is established using the binary satellite orbital position and velocity, and the component of the target satellite position vector in the local satellite orbital coordinate system is calculated. The pitch and yaw target attitude angle values ​​are calculated according to the target attitude angle definition, resulting in a pitch and yaw target attitude angle sequence composed of the pitch and yaw target attitude angle values ​​at each sampling moment. For the pitch target angle sequence, a linear average estimation is performed to calculate the average orbital period and long-term rate of change parameter, and a corrected pitch target angle sequence after deducting the long-term rate of change is given. For the pitch target angle correction sequence and the yaw target angle sequence, data with a specified average number of orbital cycles are taken starting from a specified initial time, and the fitting coefficient is calculated. The generated fitting coefficients are uploaded to the satellite, and the satellite uses the fitting coefficients to calculate the inter-satellite pitch and yaw attitude angles pointing towards the target online in each control cycle. The difference between the real-time yaw angle of the satellite and the yaw attitude angle pointing to the target between the satellites is used to obtain the yaw attitude error value, and the difference between the real-time pitch angle and the pitch attitude angle pointing to the target between the satellites is used to obtain the pitch attitude error value.

[0012] Preferably, the pitch target angle correction sequence is obtained in the following manner: Record the orbital argument in the pitch target angle sequence The time point when it first turns from negative to positive is At that moment, the pitch angle of the target is ; trajectory argument in the pitch target angle sequence The last time it turned from negative to positive was At that moment, the pitch angle of the target is ;from arrive The number of orbital periods experienced is ; Calculate the average orbital period value and long-term rate of change parameter :

[0013]

[0014] Calculate the pitch target angle correction value at each sampling time. :

[0015] in, Indicates the sampling time. Indicates the sampling time The corresponding pitch target attitude angle value, The initial time to be used for the preset command angle.

[0016] Preferably, the initial time to be used is selected from the preset command angle. start Pitch target angle correction value per average orbital period length and yaw target angle Data, calculate fitting coefficients , , , , , :

[0017] K=1,2,…

[0018] K=1,2,…

[0019]

[0020] K=1,2,…

[0021] K=1,2,…

[0022] in To control the cycle length, The fitting order is denoted as .

[0023] Preferably, the step of calculating the inter-satellite pointing-to-target attitude angle online using fitting coefficients in each satellite control cycle includes: Will , , , , , , , K=1,2,… ,total Each coefficient is uploaded to the satellite; The current time is calculated using the following formula for each control cycle on the satellite. Corresponding inter-satellite pointing pitch target attitude angle and yaw target attitude angle :

[0024]

[0025] .

[0026] The advantages of this invention compared to the prior art are: (1) This invention achieves high-precision inter-satellite pointing control by introducing a laser interferometer to measure the pointing error. (2) The present invention improves the stability of high-precision inter-satellite pointing control of satellites by combining laser interferometer measurement with orbit extrapolation calculation of inter-satellite pointing angle, and ensures high-precision, stable and continuous tracking of the laser interferometer. Attached Figure Description

[0027] Figure 1 This is a flowchart of a high-precision inter-satellite pointing control method that integrates laser interferometry according to the present invention; Detailed Implementation This invention provides a high-precision inter-satellite pointing control method that integrates laser interferometry.

[0028] Example 1: A certain two-satellite formation operates in a circular orbit at an altitude of 500 kilometers, with the two satellites about 200 kilometers apart. Both satellites are equipped with laser interferometers, and the laser interferometers are coaxial with the X-axis of the satellites. During the flight of the satellites, it is required to establish an inter-satellite pointing attitude, that is, the X-axis of the two satellites are aligned with each other and pointing to the position of the other satellite, in order to meet the working requirements of the laser interferometers.

[0029] Taking the satellites in this formation as an example, such as Figure 1 As shown, the specific steps of the present invention are as follows: (1) The validity of the attitude error value provided by the laser interferometer measurement in this cycle is judged and processed. The specific operation is as follows.

[0030] Received yaw attitude error values ​​from laser interferometer measurements for this period. pitch attitude error value Then, the yaw attitude error value provided by the laser interferometer measurement in the previous cycle was combined with the value of the previous cycle. pitch attitude error value Perform a validity check: if or or or ,or N consecutive times or If the measurement is repeated N times consecutively, the valid laser interferometer measurement flag F_LaserValid for this cycle is set to 0; otherwise, F_LaserValid is set to 1.

[0031] here and These are the yaw error threshold and pitch error threshold, respectively, determined based on the yaw attitude error range and pitch attitude error range measured by the interferometer, with appropriate margins. For example, if the yaw attitude error range measured by the interferometer does not exceed ±0.5°, a threshold of 100° can be used. It is 0.48°. The same applies to the selection of values. and These are the yaw error variation threshold and the pitch error variation threshold, respectively. They are determined based on the reasonable variation range of the yaw attitude error and the reasonable variation range of the pitch attitude error measured by the interferometer within one cycle. The satellite attitude angular velocity conditions and the interferometer measurement noise amplitude must be comprehensively considered. For example, if the satellite yaw angular velocity does not exceed ±0.01° / s when the laser interferometer is working, the control period is 0.5s, and the measurement noise of the interferometer yaw attitude error is 0.001°. A value slightly larger than 0.006°, such as 0.01°, can be used. The same applies to the selection of values. and These are the constant threshold values ​​for yaw error and pitch error, respectively, determined based on the interferometer's measurement noise amplitude. For example, if the interferometer's yaw attitude error measurement noise is 0.001°, 0.0005° can be taken. The values ​​are determined similarly. Nmin is the threshold for the constant number of attitude errors, which is generally taken as a value between 5 and 20.

[0032] (2) Based on the attitude error values ​​provided by the laser interferometer measurements in the current and previous cycles, perform attitude angular velocity difference calculation. The specific operation is as follows.

[0033] Calculate the yaw attitude differential angular velocity Calculate the pitch attitude differential angular velocity .

[0034] here To control the cycle length.

[0035] (3) When the attitude error value provided by the laser interferometer measurement in this cycle is valid, the provided attitude error value is determined by combining the orbit extrapolation and the on-board attitude, and the reference error is calculated. The specific operation is as follows.

[0036] If F_LaserValid is 1, the provided yaw attitude error value is determined by combining on-board orbit extrapolation and attitude assessment. pitch attitude error value Calculate the yaw reference error pitch attitude error : , , here and Yaw reference error pitch attitude error The calculated value of the previous period, The reference error filtering coefficient is typically taken as a value between 0.02 and 0.2. Here, the yaw attitude error value is provided by the onboard orbit extrapolation and attitude determination. pitch attitude error value The calculation is described as follows: The satellite calculates the orbital positions of its own satellite and the target satellite by extrapolating from the binary orbit, and then calculates the inter-satellite pointing target angle. Since inter-satellite pointing requires the X-axis of the two satellites to point towards the position of the target satellite, the roll target angle of the inter-satellite pointing target angle is 0 unless otherwise specified. The pitch and yaw target angles are calculated by decomposing the position vector direction of the target satellite relative to the own satellite into the three axes of the own orbital system. The satellite's three-axis attitude angles are calculated using conventional attitude determination methods such as star-aware attitude determination. Then, the difference between the satellite's attitude angles and the inter-satellite pointing target angle is calculated to obtain the yaw attitude error value. pitch attitude error value Rolling attitude error value Similar to the satellite roll attitude angle, conventional attitude determination methods such as star-aware attitude determination also provide the satellite's three-axis attitude angular velocity. , , The calculation is used in subsequent steps. Among them, the yaw attitude error value... pitch attitude error value The calculation can also be performed using the preferred embodiment given in this invention: (a1) The ground generates a sequence of binary orbital position and velocity values ​​for a predetermined time period and samples them according to the control cycle. For each sampling time, the local orbital coordinate system is established using the binary orbital position and velocity, and the component of the target star position vector in the local orbital coordinate system is calculated. The pitch and yaw target attitude angle values ​​are calculated according to the definition of the target attitude angle, and a pitch and yaw target attitude angle sequence composed of the pitch and yaw target attitude angle values ​​at each sampling time is obtained. For each sampling time, the pitch and yaw target attitude angles are calculated as follows: Calculate the transformation matrix between the local orbital coordinate system and the J2000 inertial coordinate system. ; Calculate the components of the target star's position vector in its local orbit coordinate system. ; Calculate the pitch and yaw target attitude angles based on the definition of target attitude angles, i.e., the pitch target attitude angles. and yaw target attitude angle ; When it appears When the yaw target attitude angle is at that time, the following assignment formula is used to process the yaw target attitude angle. .

[0037] (a2) Perform linear averaging estimation on the pitch target angle sequence, calculate the average orbital period value and long-term rate of change parameter, and give the pitch target angle correction sequence after deducting the long-term rate of change; The above pitch target angle correction sequence can be determined in the following way: Record the orbital argument in the pitch target angle sequence The time point when it first turns from negative to positive is At that moment, the pitch angle of the target is ; trajectory argument in the pitch target angle sequence The last time it turned from negative to positive was At that moment, the pitch angle of the target is ;from arrive The number of orbital periods experienced is ; Calculate the average orbital period value and long-term rate of change parameter :

[0038]

[0039] Calculate the pitch target angle correction value at each sampling time. :

[0040] in, Indicates the sampling time. Indicates the sampling time The corresponding pitch target attitude angle value, The initial time to be used for the preset command angle.

[0041] (a3) For the pitch target angle correction sequence and yaw target angle sequence, take data with a specified average number of orbital periods starting from the specified initial time and calculate the fitting coefficient; Take from The moment begins Pitch target angle correction value per average orbital period length and yaw target angle The data is used to calculate the fitting coefficient. , , , , , :

[0042] K=1,2,…

[0043] K=1,2,…

[0044]

[0045] K=1,2,…

[0046] K=1,2,…

[0047] in To control the cycle length, The fitting order is denoted as .

[0048] (a4) The generated fitting coefficients are uploaded to the satellite. The satellite uses the fitting coefficients to calculate the inter-satellite pointing attitude angle to the target online in each control cycle.

[0049] The current time is calculated using the following formula for each control cycle on the satellite. Corresponding inter-satellite pointing pitch target attitude angle and yaw target attitude angle :

[0050]

[0051]

[0052]

[0053]

[0054] (4) Based on the validity of the attitude error values ​​provided by the laser interferometer measurements in the current and previous cycles, and based on the reference introduction / direct introduction selection flag set on the ground, determine whether to perform reference introduction calculation or direct introduction calculation. The specific operation is as follows.

[0055] The ground-based reference introduction / direct introduction selection flag FP_LaserGuide is set to 0 to indicate reference introduction and 1 to indicate direct introduction. When FP_LaserGuide is 1, and the validity of the attitude error value provided by the laser interferometer measurement in the current cycle (F_LaserValid) and the validity of the attitude error value provided by the laser interferometer measurement in the previous cycle (F_LaserValidlst) are both 1, then the introduction calculation mode flag F_LaserGuide is determined to be 1, indicating that direct introduction calculation is performed. Otherwise, when at least one of FP_LaserGuide, F_LaserValid, and F_LaserValidlst is 0, the introduction calculation mode flag F_LaserGuide is determined to be 0, indicating that reference introduction calculation is performed.

[0056] (5) When implementing direct input calculation, the attitude control quantity and angular velocity control quantity are calculated based on the attitude error value and attitude angular velocity difference calculation results provided by the laser interferometer measurement. The specific operation is as follows.

[0057] If the calculation method flag F_LaserGuide is set to 1, then the three-axis attitude control quantity , , and three-axis angular velocity control quantity , , The calculation is as follows: , , , , ,

[0058] (6) When performing reference-based calculations, the attitude control quantity and angular velocity control quantity are calculated based on the attitude error value provided by orbit extrapolation and the reference error calculation results. The specific operation is as follows.

[0059] If the calculation method flag F_LaserGuide is set to 0, then the three-axis attitude control quantity... , , and three-axis angular velocity control quantity , , The calculation is as follows: , , , , ,

[0060] (7) Based on the attitude control quantity and angular velocity control quantity, the attitude control torque is calculated using the control law and implemented by the actuator. The specific operation is as follows.

[0061] The desired control torque is calculated using a control law such as PD or PID based on the attitude control variable and the attitude angular velocity control variable. Here, we use the PD control law: ,in It is a 3*1 dimensional array. and All are 3*3 dimension control coefficients. and These are the vector forms of the three-axis attitude control quantity and the three-axis attitude angular velocity control quantity, respectively. PD or PID control laws are fundamental methods for control system design. The control coefficients must meet constraints such as control stability. For specific methods, please refer to works such as Hu Shousong's "Principles of Automatic Control". Where possible, the disturbance torque experienced by the satellite can be estimated and compensated for in the calculation of the desired control torque. For example, the estimated value of the satellite's gravity gradient torque can be calculated. ,here The desired control torque calculation is changed to a 3*1 dimensional array. For calculations of disturbance torques such as gravity gradient torque, please refer to the relevant chapters in Zhang Renwei's "Satellite Orbit and Attitude Dynamics Control".

[0062] When the desired control torque is applied by the actuator, the control signal given to the actuator is determined by the specific type of actuator and its installation method. For example, a satellite may have a momentum wheel installed in each of its three positive axes, and the voltage-to-torque conversion factor of the momentum wheel is... Then, without considering friction compensation, the momentum wheel control voltage is calculated from the desired control torque. The formula is: ,in The control voltage is a 3*1 dimensional array. The output is sent to three momentum wheels, which drive the momentum wheels to generate corresponding control torques. For details, please refer to the chapter on actuators in "Satellite Attitude Dynamics and Control" edited by Academician Tu Shancheng.

[0063] The above description is only the best specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the protection scope of the present invention.

[0064] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A high-precision inter-satellite pointing control method integrating laser interferometry, characterized in that: During satellite flight, an inter-satellite pointing attitude is established, meaning the X-axis of the two satellites are aligned with each other, pointing towards the position of the other satellite; both satellites are equipped with laser interferometers, and the laser interferometers are coaxial with the X-axis of their respective satellites; the method includes: Based on the attitude error value provided by the laser interferometer measurement in the previous cycle, the validity of the attitude error value provided by the laser interferometer measurement in the current cycle is judged and processed, and the attitude angular velocity difference is calculated. When the attitude error value provided by the laser interferometer measurement in this cycle is valid, the reference error is calculated by combining the attitude error value provided by orbit extrapolation and on-board attitude determination. Based on the validity judgment results of the attitude error values ​​provided by the laser interferometer measurements in the current and previous cycles, and based on the reference introduction / direct introduction selection flag set on the ground, it is determined whether to implement reference introduction calculation or direct introduction calculation; when implementing direct introduction calculation, the attitude control quantity and angular velocity control quantity are calculated based on the attitude error value provided by the laser interferometer measurement and the attitude angular velocity difference calculation result; when implementing reference introduction calculation, the attitude control quantity and angular velocity control quantity are calculated based on the attitude error value provided by orbit extrapolation and the reference error calculation result. Finally, based on the attitude control quantity and angular velocity control quantity, the attitude control torque is calculated using the control law and implemented by the actuator.

2. The method according to claim 1, characterized in that: Validity judgments include: like or or or ,or N consecutive times or If the measurement is repeated N times consecutively, the valid laser interferometer measurement flag F_LaserValid for this cycle is set to 0; otherwise, F_LaserValid is set to 1. in, , These are the yaw attitude error values ​​and pitch attitude error values ​​provided by the laser interferometer measurements during this cycle, respectively. , These are the yaw attitude error values ​​and pitch attitude error values ​​provided by the laser interferometer measurements in the previous cycle, respectively. and These are the yaw error threshold and the pitch error threshold, respectively. To control the cycle length, and These are the threshold values ​​for yaw error variation and pitch error variation, respectively. and These are the yaw constant threshold and pitch constant threshold, respectively. Nmin is the threshold for the number of attitude error constants. F_LaserValid is 1 for valid and 0 for invalid.

3. The method according to claim 2, characterized in that: The value of Nmin is 5 to 20. and Set the values ​​by subtracting K1 from the effective ranges of the yaw attitude error and pitch attitude error provided by the laser interferometer, respectively. and The settings are calculated by multiplying the satellite's yaw rate error index and pitch rate error index (when using a laser interferometer) by the control period length and then adding K2. and Set the parameters by multiplying the attitude noise index measured by the laser interferometer by K3; K1 takes values ​​from 0.01º to 0.1º, K2 takes values ​​from 0.001º to 0.1º, and K3 takes values ​​from 0.1 to 0.

9.

4. The method according to claim 1, characterized in that: The yaw attitude error value provided by combining on-board orbit extrapolation and attitude determination pitch attitude error value Calculate the yaw reference error and pitch reference error : ， ， In the formula, and Yaw reference error and pitch reference error The calculated value of the previous period, The reference error filtering coefficient is set to a value between 0.02 and 0.

2.

5. The method according to claim 1, characterized in that: The method for determining whether to implement a reference-introduced calculation or to directly introduce the calculation is as follows: The ground-based reference introduction / direct introduction selection flag FP_LaserGuide is set to 0 to indicate reference introduction and 1 to indicate direct introduction. When FP_LaserGuide is 1, and the validity of the attitude error value provided by the laser interferometer measurement in the current cycle (F_LaserValid) and the validity of the attitude error value provided by the laser interferometer measurement in the previous cycle (F_LaserValidlst) are both 1, then the introduction calculation mode flag F_LaserGuide is determined to be 1, indicating that direct introduction calculation is performed. Otherwise, when at least one of FP_LaserGuide, F_LaserValid, and F_LaserValidlst is 0, the introduction calculation mode flag F_LaserGuide is determined to be 0, indicating that reference introduction calculation is performed.

6. The method according to claim 1, characterized in that: When implementing reference-introduction calculations, the three-axis attitude control quantities of roll, pitch, and yaw are... , , and three-axis angular velocity control quantity , , The calculation is as follows: ， ， ， ， ， , The yaw and pitch attitude error angles provided for orbit extrapolation and attitude determination, respectively, are for orbit extrapolation and attitude determination. , These are the yaw reference error and the pitch reference error, respectively. For satellite real-time roll angle, , , It provides the real-time roll, pitch, and yaw attitude angular velocities of the satellite.

7. The method according to claim 6, characterized in that: The yaw and pitch attitude error angles provided by on-board orbit extrapolation and attitude determination are determined through real-time online prediction in orbit. Specific steps include: The ground generates a sequence of binary satellite orbital position and velocity values ​​for a predetermined time period and samples them according to the control cycle. For each sampling moment, the local satellite orbital coordinate system is established using the binary satellite orbital position and velocity, and the component of the target satellite position vector in the local satellite orbital coordinate system is calculated. The pitch and yaw target attitude angle values ​​are calculated according to the target attitude angle definition, resulting in a pitch and yaw target attitude angle sequence composed of the pitch and yaw target attitude angle values ​​at each sampling moment. For the pitch target angle sequence, a linear average estimation is performed to calculate the average orbital period and long-term rate of change parameter, and a corrected pitch target angle sequence after deducting the long-term rate of change is given. For the pitch target angle correction sequence and the yaw target angle sequence, data with a specified average number of orbital cycles are taken starting from a specified initial time, and the fitting coefficient is calculated. The generated fitting coefficients are uploaded to the satellite, and the satellite uses the fitting coefficients to calculate the inter-satellite pitch and yaw attitude angles pointing towards the target online in each control cycle. The difference between the real-time yaw angle of the satellite and the yaw attitude angle pointing to the target between the satellites is used to obtain the yaw attitude error value, and the difference between the real-time pitch angle and the pitch attitude angle pointing to the target between the satellites is used to obtain the pitch attitude error value.

8. The method according to claim 7, characterized in that: The elevation target angle correction sequence is obtained in the following manner: Record the orbital argument in the pitch target angle sequence The time point when it first turns from negative to positive is At that moment, the pitch angle of the target is ; trajectory argument in the pitch target angle sequence The last time it turned from negative to positive was At that moment, the pitch angle of the target is ;from arrive The number of orbital periods experienced is ; Calculate the average orbital period value and long-term rate of change parameter : Calculate the pitch target angle correction value at each sampling time. : in, Indicates the sampling time. Indicates the sampling time The corresponding pitch target attitude angle value, The initial time to be used for the preset command angle.

9. The method according to claim 7, characterized in that: Take the initial time to be used from the preset command angle. start Pitch target angle correction value per average orbital period length and yaw target angle Data, calculate fitting coefficients , , , , , : ，K=1,2,…, ，K=1,2,…, ，K=1,2,…, ，K=1,2,…, in To control the cycle length, The fitting order is denoted as .

10. The method according to claim 7, characterized in that: The steps for calculating the inter-satellite pointing attitude angle to the target online using fitting coefficients in each satellite control cycle include: Will , , , , , , , K=1,2,… ,total Each coefficient is uploaded to the satellite; The current time is calculated using the following formula for each control cycle on the satellite. Corresponding inter-satellite pointing pitch target attitude angle and yaw target attitude angle : 。

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