Satellite sun-pointing control method with optimal thermal balance

Abstract

The application discloses a satellite sun-pointing control method with optimal heat balance. The method comprises the following steps: firstly, determining sun-pointing target parameters according to a calculated sun vector direction; when preset parameters are set, using the preset sun-pointing target parameters; then, calculating sun-pointing target attitude angles and angular velocities by using a formula provided by the method; and finally, realizing sun-pointing of the satellite according to the sun-pointing target attitude angles and angular velocities by using a sun-sensing gyro measurement and a jet phase plane control.

Description

Technical Field

[0001] This invention relates to the field of spacecraft attitude control, and in particular to a thermally balanced satellite sun-orientation control method applicable to all spacecraft with sun-orientation thermal balance requirements. Background Technology

[0002] To ensure the overall thermal control safety of the satellite, when orienting it towards the sun, its bottom surface (+Z plate) should be as close to the Earth as possible to fully utilize the Earth's irradiation heating function. For non-sunsynchronous orbit satellites, the positional relationship between the Sun, Earth, and satellite is constantly changing, making it impossible to guarantee the correct orientation to the ground under all circumstances using a single sun-orientation attitude. Furthermore, when the satellite malfunctions and switches to sun-orientation, attitude measurement equipment such as star sensors typically malfunctions, making it impossible to obtain the satellite's attitude information relative to the ground, further complicating the problem. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a satellite solar orientation control method with optimal thermal balance. By dynamically adjusting the solar orientation target angle and angular velocity through the relative relationship between the solar vector and the satellite orbit, the bottom surface of the satellite is kept as close to the Earth as possible in the absence of Earth attitude information, so as to make full use of the Earth's irradiation heating function and optimize the satellite thermal balance conditions.

[0004] The technical solution of this invention is: a satellite sun-orientation control method with optimal thermal balance, comprising:

[0005] Perform satellite sun orientation initialization, determine if there are periodically preset parameters, and if so, use the preset sun orientation target parameters; otherwise, calculate the solar vector direction based on the orbit, and then determine the sun orientation target parameters.

[0006] Calculate the attitude angle and angular velocity of the sun-oriented target based on the parameters of the sun-oriented target;

[0007] The satellite achieves solar orientation by using a solar sensor, gyroscope measurements, and jet phase plane control to determine the target's attitude angle and angular velocity.

[0008] Preferably, the attitude angle and angular velocity of the sun-oriented target are calculated as follows:

[0009] Determine the target attitude angle Φ for sun orientation based on the nominal sun orientation attitude when the satellite solar panel is directly facing the sun. T That is; Φ T It is a 3*1 dimension array, and each component represents the offset angle of the relative nominal sun-oriented attitude in the roll, pitch, and yaw directions, respectively;

[0010] Based on the constructed attitude angle Φ of the sun-oriented target TDetermine the attitude angular velocity of the sun-oriented target. Ensure that the satellite's attitude angle remains unchanged as it rotates around the designated direction at the target angular velocity.

[0011] Preferably, the calculation of the attitude angle of the sun-oriented target includes three working conditions: working condition one is that the normal of the solar panel is oriented towards the satellite body - Z-axis direction, working condition two is that the normal of the solar panel is oriented towards the satellite body - Y-axis direction, and working condition three is that the normal of the solar panel is oriented towards the satellite body - X-axis direction.

[0012] In operating condition one, the yaw direction offset angle is 0, Φ T =[Φ bias Θ bias 0] T In working condition two, the pitch offset angle is 0, Φ T =[Φ bias 0Ψ bias ] T In operating condition three, the rolling direction offset angle is 0, Φ T =[0Θ bias Ψ bias ] T ;

[0013] Φ bias Θ bias Ψ bias These are the offset angles for the roll, pitch, and yaw directions in the parameters for directional targets towards the sun.

[0014] Preferably, in operating condition one, the attitude angular velocity of the sun-oriented target is calculated using the following formula:

[0015]

[0016] For condition two, the attitude angular velocity of the sun-oriented target is calculated using the following formula:

[0017]

[0018] For operating condition three, the attitude angular velocity of the sun-oriented target is calculated using the following formula:

[0019]

[0020] Where ω0 is the absolute value of the orbital angular velocity, K rotate This is the slow-rotation coefficient in the parameters of the sun-oriented target.

[0021] Preferably, when there are no periodically preset parameters, the day-orientation target parameters are determined in the following manner:

[0022] During initialization, the solar β angle is determined based on the solar vector direction calculated from the satellite orbit;

[0023] The ZoneFlag setting for the target area for the sun is determined based on the solar β angle.

[0024] If β < β zone If it is, then set ZoneFlag = 1; otherwise, set ZoneFlag = 0.

[0025] Where β zone Set the β angle threshold for the solar region;

[0026] Determine the parameters for the Japan-oriented target based on the ZoneFlag setting value:

[0027] If ZoneFlag = 1, let:

[0028] Φ bias =Φ bias1 Ψ bias =Ψ bias1 K rotate =K rotate1 ,

[0029] Otherwise, if ZoneFlag = 0, let:

[0030] Φ bias =Φ bias0 Ψ bias =Ψ bias0 K rotate =K rotate0 ,

[0031] Where Φ bias1 Ψ bias1 K rotate1 and Φ bias0 Ψ bias0 K rotate0 The desired target parameters for targeting the sun in two different target areas.

[0032] Preferably, the satellite's solar orientation to the target's attitude angle and angular velocity based on the sun sensor, gyroscope measurement, and jet phase plane control includes:

[0033] The satellite's attitude angular velocity ω relative to the sun was calculated based on gyroscope measurements. att ;

[0034] Determine if there is a signal from the sun sensor. If there is a signal, use the sun sensor to measure and calculate the solar attitude angle Φ. att =[φ s -φ Y θ s ψ s ] T When the solar sensor has no signal, Φ att =Φ attlast +ω attΔt;

[0035] According to Φ c =Φ att -Φ T , Calculate the attitude angle control quantity Φ for jet phase plane control. c and angular velocity control quantity ω c ;

[0036] Among them, pitch attitude angle θ s =θ slast +ω att (2) Δt, θ slast It is the pitch attitude angle calculated in the previous cycle, with an initial value of 0, ω att (2) represents ω att The second component, Δt, is the control period; ψ s For yaw sensitivity measurement angle, φ s For rolling sensitive measurement of angle, φ Y Φ is the angle between the side of the satellite and the satellite's Y-axis. attlast This represents the attitude angle relative to the sun calculated in the previous cycle.

[0037] A thermally balanced satellite sun-alignment control system, comprising:

[0038] The initialization module initializes the satellite's sun orientation and determines whether there are pre-set parameters. If so, the pre-set sun orientation target parameters are used; otherwise, the solar vector direction is calculated based on the orbit to determine the sun orientation target parameters.

[0039] The parameter calculation module calculates the attitude angle and angular velocity of the sun-oriented target based on the parameters of the sun-oriented target.

[0040] The sun-orientation control module uses gyroscope measurements and jet phase plane control to orient the satellite toward the sun based on its attitude angle and angular velocity.

[0041] Preferably, the satellite's solar orientation to the target's attitude angle and angular velocity based on the sun sensor, gyroscope measurement, and jet phase plane control includes:

[0042] The satellite's attitude angular velocity ω relative to the sun was calculated based on gyroscope measurements. att ;

[0043] Determine if there is a signal from the sun sensor. If there is a signal, use the sun sensor to measure and calculate the solar attitude angle Φ. att =[φ s -φ Y θ s ψ s ] T When the solar sensor has no signal, Φ att =Φattlast +ω att Δt;

[0044] According to Φ c =Φ att -Φ T , Calculate the attitude angle control quantity Φ for jet phase plane control. c and angular velocity control quantity ω c ;

[0045] Among them, pitch attitude angle θ s =θ slast +ω att (2) Δt, θ slast It is the pitch attitude angle calculated in the previous cycle, with an initial value of 0, ω att (2) represents ω att The second component, Δt, is the control period; ψ s For yaw sensitivity measurement angle, φ s For rolling sensitive measurement of angle, φ Y Φ is the angle between the side of the satellite and the satellite's Y-axis. attlast This represents the attitude angle relative to the sun calculated in the previous cycle.

[0046] A computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the thermally balanced satellite sun-orientation control method.

[0047] A computer software product includes: a processor and a storage device;

[0048] Storage device for storing one or more programs.

[0049] When the one or more programs are executed by one or more processors, the one or more processors implement the thermally optimal satellite sun-orientation control method.

[0050] The advantages of this invention compared to the prior art are:

[0051] This invention discloses a thermally optimal satellite sun-orientation control method. Based on the orbital sun direction, it dynamically adjusts the sun-orientation target angle and angular velocity, ensuring the satellite's bottom surface is as close to the Earth as possible even when Earth-orientation attitude information is lacking. This ingeniously solves the problem of...

[0052] This invention dynamically adjusts the angle and angular velocity of the sun-oriented target by adjusting the orbital sun direction, ensuring that the bottom surface of the satellite is as close to the Earth as possible in the absence of Earth attitude information, thus ensuring the satellite's thermal balance.

[0053] This invention solves the problem of controlling the orientation of non-sunsynchronous orbit satellites to the Earth by relying only on partial orbital information or periodic ground-based designation, and is an ingenious solution for satellite thermal balance. Attached Figure Description

[0054] Figure 1 This is a flowchart of a satellite solar orientation control method with optimal thermal balance according to the present invention; Detailed Implementation

[0055] Example 1:

[0056] Taking a low-Earth orbit satellite with an orbital inclination of around 90 degrees as an example, such as Figure 1 As shown, the specific steps of the present invention are as follows:

[0057] (1) Determine the solar orientation target parameters based on the solar vector direction calculated from the orbit. If periodic preset parameters are set, use the preset solar orientation target parameters. During algorithm initialization, determine the solar β angle based on the solar vector direction calculated from the satellite orbit.

[0058] β=|arcsin(S oy )|,

[0059] Where S oy It represents the component value of the solar vector in the direction of the normal to the satellite orbit coordinate system, and |·| indicates taking the absolute value.

[0060] The ZoneFlag setting for the target area for the sun is determined based on the solar β angle.

[0061] If β < β zone If it is, then set ZoneFlag = 1; otherwise, set ZoneFlag = 0.

[0062] Where β zone A β-angle threshold is set for the solar orientation region to distinguish between two different solar orientation target parameters.

[0063] When a periodic preset parameter ZoneFlagDefault is set (with a value of 0, 1, or other possible values), set ZoneFlag = ZoneFlagDefault. The purpose of setting the periodic preset parameter is to allow the ground to set the target area for the sun. For example, if the satellite's onboard orbit calculation may be incorrect or for other special reasons, the ground can directly specify the target area for the satellite based on the current and periodic solar β angle range, and re-specify the appropriate target area for the sun by ground annotation when the solar β angle changes to other ranges.

[0064] Determine the parameters for the Japan-oriented target based on the ZoneFlag setting value:

[0065] If ZoneFlag = 1, let:

[0066] Φ bias =Φ bias1 Θ bias =Θ bias1 Ψ bias =Ψ bias1 K rotate =K rotate1 ,

[0067] Otherwise, if ZoneFlag = 0, let:

[0068] Φ bias =Φ bias0 Θ bias =Θ bias0 Ψ bias =Ψ bias0 K rotate =K rotate0 ,

[0069] Where Φ bias1 Θ bias1 Ψ bias1 K rotate1 and Φ bias0 Θ bias0 Ψ bias0 K rotate0 These are two sets of solar orientation target parameter values, representing the desired solar orientation target in two different solar orientation target areas. These are used for subsequent calculations of the solar orientation target's attitude angle and angular velocity. For example, setting Φ... bias1 =π / 6, Θ bias1 =0,Ψ bias1 =0,K rotate1 =0, set Φ bias0 =π / 3, Θ bias0 =0,Ψ bias0 =0,K rotate0 =0.5, meaning that in target area 1, the target is rolled off by 30 degrees and stationary, while in target area 0, the target is rolled off by 60 degrees and slowly rotated at 0.5 times the orbital angular velocity. This ensures the satellite's thermal balance for different solar positions. If other ZoneFlag values ​​are set on the ground, the corresponding target parameter values ​​must also be set.

[0070] (2) Calculate the attitude angle and angular velocity of the sun-oriented target using the formulas provided in this method; the attitude angle Φ of the sun-oriented target TThis is a 3*1 dimensional array, where each component represents the target angle in the roll, pitch, and yaw directions, respectively. The sun-oriented target attitude angle is the offset angle relative to the nominal sun-oriented attitude. Since the sun direction is a vector, the offset direction only requires the offset angles in two directions to fully describe it. Therefore, at least one of the target angles in the roll, pitch, and yaw directions must be 0; when all three are 0, it is consistent with the nominal sun-oriented attitude. The nominal sun-oriented attitude is the attitude when the solar panel normal is directly facing the sun. Here, we consider three general operating conditions: Condition 1, where the solar panel normal is oriented towards the satellite body - Z-axis; Condition 2, where the solar panel normal is oriented towards the satellite body - Y-axis; and Condition 3, where the solar panel normal is oriented towards the satellite body - X-axis.

[0071] For condition one, only the roll and pitch directions need to be offset, and the attitude angle of the sun-oriented target is calculated using the following formula:

[0072] Φ T =[Φ bias Θ bias 0] T ,

[0073] For condition two, only the roll and yaw directions need to be offset, and the attitude angle of the day-oriented target is calculated using the following formula:

[0074] Φ T =[Φ bias 0Ψ bias ] T ,

[0075] For condition three, only the pitch and yaw directions need to be offset, and the attitude angle of the sun-oriented target is calculated using the following formula:

[0076] Φ T =[0Θ bias Ψ bias ] T ,

[0077] Attitude angular velocity of sun-oriented target It is a 3*1 dimensional array, and each component represents the target angular velocity in the roll, pitch, and yaw directions, respectively.

[0078] For condition one, the attitude angular velocity of the sun-oriented target is calculated using the following formula:

[0079]

[0080] For condition two, the attitude angular velocity of the sun-oriented target is calculated using the following formula:

[0081]

[0082] For working condition three, the attitude angular velocity of the sun-oriented target is calculated using the following formula:

[0083]

[0084] Where ω0 is the absolute value of the orbital angular velocity.

[0085] (3) The satellite's attitude angle and angular velocity toward the target are determined by the Taimin gyroscope measurement and jet phase plane control; the satellite's attitude angular velocity ω toward the target is calculated based on the gyroscope measurement. att This is a 3*1 dimensional array, with three components representing the angular velocity of the satellite relative to the inertial coordinate system along the roll, pitch, and yaw axes of the satellite's coordinate system:

[0086] ω att =inv(R*R T )R*g

[0087] Where g represents the angular velocity values ​​measured by each gyroscope axis, and is an N*1 dimensional array, where N is the number of gyroscopes used, and R = [R1 R2 ... R N [ ] is the gyroscope mounting matrix, a 3*N dimensional matrix, where each component R n n = 1, 2, ..., N are all 3*1 dimensional arrays, representing the components of the measurement direction vectors of each gyroscope used in the satellite body coordinate system, R T Let R denote the transpose of R, and inv(·) denotes the inverse function.

[0088] Calculate the satellite's attitude angle relative to the sun based on Taimin measurements:

[0089] The calculation of the solar attitude angle is related to the installation orientation of the solar sensor. For example, here the calculation is performed assuming that the solar sensor is installed parallel to the satellite +Y inclined plane, the bottom edge of the satellite +Y inclined plane is parallel to the satellite X-axis, and the side edge makes an angle φ with the satellite -Y axis. Y Degrees, 90-φ with the satellite's Z-axis Y The direction of the roll-sensitive angle change is consistent with the satellite's +X axis, and the positive direction of the yaw-sensitive angle change is consistent with the satellite's +Y axis. That is, when the sun is located in the satellite's -Z axis direction, the roll-sensitive angle φ is measured. s =φ Y Yaw sensitivity measurement angle ψ s =0. The corresponding solar attitude angle Φ att The calculation formula is:

[0090] Φ att =[φ s -φ Y θ s ψ s ] T ,

[0091] Where the pitch attitude angle θ s =θ slast +ωatt (2)Δt, where θ slast It is the pitch attitude angle calculated in the previous cycle, with an initial value of 0, ω att (2) represents ω att The second component, Δt, is the control period.

[0092] When there is no signal due to factors such as the satellite being in the Earth's shadow, the following formula can be used to calculate the solar attitude angle Φ. att :

[0093] Φ att =Φ attlast +ω att Δt

[0094] Where Φ attlast This represents the attitude angle relative to the sun calculated in the previous cycle.

[0095] Then, the attitude angle control quantity Φ used for jet phase plane control is calculated. c and angular velocity control quantity ω c All are 3*1 dimensional arrays:

[0096] Φ c =Φ att -Φ T ,

[0097] For the specific algorithm of jet phase plane control, please refer to page 442 of "Satellite Attitude Dynamics and Control" (Aerospace Press, 2001), edited by Academician Tu Shancheng.

[0098] 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.

[0099] This invention also provides a thermally balanced satellite sun-orientation control system, characterized by comprising:

[0100] The initialization module initializes the satellite's sun orientation and determines whether there are pre-set parameters. If so, the pre-set sun orientation target parameters are used; otherwise, the solar vector direction is calculated based on the orbit to determine the sun orientation target parameters.

[0101] The parameter calculation module calculates the attitude angle and angular velocity of the sun-oriented target based on the parameters of the sun-oriented target.

[0102] The sun-orientation control module uses gyroscope measurements and jet phase plane control to orient the satellite toward the sun based on its attitude angle and angular velocity.

[0103] For details on the implementation of relevant functions in the system, please refer to the relevant descriptions in the methods.

[0104] The present invention further provides a computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the thermal balance optimal satellite sun-orientation control method.

[0105] The present invention also provides a computer software product, comprising: a processor and a storage device;

[0106] Storage device for storing one or more programs.

[0107] When the one or more programs are executed by one or more processors, the one or more processors implement the thermally optimal satellite sun-orientation control method.

[0108] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A satellite sun-orientation control method with optimal thermal balance, characterized in that... include: Perform satellite sun orientation initialization, determine if there are periodically preset parameters, and if so, use the preset sun orientation target parameters; If not, the direction of the solar vector is calculated based on the orbit, and then the parameters of the solar orientation target are determined. Calculate the attitude angle and angular velocity of the sun-oriented target based on the parameters of the sun-oriented target; The satellite achieves solar orientation by using a solar sensor, gyroscope measurements, and jet phase plane control to determine the target's attitude angle and angular velocity.

2. The method according to claim 1, characterized in that: The attitude angles and angular velocities of the sun-oriented target are calculated as follows: Determine the target attitude angle for sun orientation based on the nominal sun-orienting attitude when the satellite's solar panels are facing the sun normally. ,Right now; 3 A 1D array, where each component represents the offset angle of the relative nominal sun-oriented attitude in the roll, pitch, and yaw directions, respectively; Based on the constructed attitude angle of the sun-oriented target Determine the attitude angular velocity of the sun-oriented target. This ensures that the satellite's attitude angle remains constant while it rotates around the designated direction at the target angular velocity.

3. The method according to claim 2, characterized in that: The calculation of the attitude angle of the sun-oriented target includes three working conditions: working condition one is that the normal of the solar panel is oriented towards the satellite body - Z-axis direction, working condition two is that the normal of the solar panel is oriented towards the satellite body - Y-axis direction, and working condition three is that the normal of the solar panel is oriented towards the satellite body - X-axis direction. In operating condition one, the yaw direction offset angle is 0. ; In working condition two, the pitch offset angle is 0. ; In operating condition three, the rolling direction offset angle is 0. ; , , These are the offset angles for the roll, pitch, and yaw directions in the parameters for directional targets towards the sun.

4. The method according to claim 3, characterized in that: For condition one, the attitude angular velocity of the sun-oriented target is calculated using the following formula: ， For condition two, the attitude angular velocity of the sun-oriented target is calculated using the following formula: ， For operating condition three, the attitude angular velocity of the sun-oriented target is calculated using the following formula: in The absolute value of the orbital angular velocity. This is the slow-rotation coefficient in the parameters of the sun-oriented target.

5. The method according to claim 1, characterized in that: When there are no pre-set parameters, the parameters for the day-orientation target are determined as follows: During initialization, the direction of the solar vector calculated from the satellite orbit is determined. horn; According to the sun Angle determines the target area setting value for the sun : like Then let Otherwise , in For setting up a region for Japan Angular threshold; Based on the target area setting value for Japan Determine the parameters for the Japan-oriented target: like season: ， ， ， ， Otherwise if season: ， ， ， ， in , , , and , , , The desired target parameters for targeting the sun in two different target areas.

6. The method according to claim 1, characterized in that: Achieving satellite orientation to the sun based on target attitude angles and angular velocities using sun sensors, gyroscope measurements, and jet phase-plane control includes: The satellite's attitude angular velocity relative to the sun was calculated based on gyroscope measurements. ; Determine if there is a signal from the sun sensor; if so, use the sun sensor to measure and calculate the solar attitude angle. When the solar sensor has no signal, ; according to , Calculate the attitude angle control parameters for jet phase plane control. and angular velocity control quantity ; Among them, pitch attitude angle , This is the pitch attitude angle calculated in the previous cycle, with an initial value of 0. express The second component, To control the cycle; For yaw sensitivity measurement angle, To measure the angle of the rolling thermocouple, The angle between the side of the satellite and the satellite's Y-axis; This represents the attitude angle relative to the sun calculated in the previous cycle.

7. A satellite sun-alignment control system with optimal thermal balance, characterized in that... include: The initialization module initializes the satellite's sun orientation and determines whether there are periodically preset parameters. If so, it uses the preset sun orientation target parameters. If not, the direction of the solar vector is calculated based on the orbit, and then the parameters of the solar orientation target are determined. The parameter calculation module calculates the attitude angle and angular velocity of the sun-oriented target based on the parameters of the sun-oriented target. The sun-orientation control module uses gyroscope measurements and jet phase plane control to orient the satellite toward the sun based on its attitude angle and angular velocity.

8. The system according to claim 7, characterized in that: Achieving satellite orientation to the sun based on target attitude angles and angular velocities using sun sensors, gyroscope measurements, and jet phase-plane control includes: The satellite's attitude angular velocity relative to the sun was calculated based on gyroscope measurements. ; Determine if there is a signal from the sun sensor; if so, use the sun sensor to measure and calculate the solar attitude angle. When the solar sensor has no signal, ; according to , Calculate the attitude angle control parameters for jet phase plane control. and angular velocity control quantity ; Among them, pitch attitude angle , This is the pitch attitude angle calculated in the previous cycle, with an initial value of 0. express The second component, To control the cycle; For yaw sensitivity measurement angle, To measure the angle of the rolling thermocouple, The angle between the side of the satellite and the satellite's Y-axis; This represents the attitude angle relative to the sun calculated in the previous cycle.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the thermal balance optimal satellite sun orientation control method as described in any one of claims 1 to 4.

10. A computer software product, characterized in that... include: Processors and storage devices; Storage device for storing one or more programs. When the one or more programs are executed by one or more processors, the one or more processors implement a thermally balanced, sun-oriented control method for satellites as described in any one of claims 1 to 4.

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