Satellite real-time pointing angle acquisition, error calculation and control method and control system

Abstract

This invention provides a method and control system for acquiring, calculating, and controlling the real-time pointing angle of a satellite. The method for acquiring the real-time pointing angle includes: acquiring several sets of orbit acquisition data and attitude acquisition data closest to the current feeding time, wherein the orbit acquisition data and attitude acquisition data have timestamps identifying their acquisition time; determining the orbit data and attitude data at the current feeding time based on the orbit acquisition data and attitude acquisition data; and determining the pointing angle of the satellite towards its target ground station at the current feeding time based on the orbit data and attitude data at the current feeding time, as the real-time pointing angle of the satellite at the current feeding time.

Description

Technical Field

[0001] This invention relates to the field of satellite pointing angle control, and in particular to a method and control system for acquiring, calculating and controlling the real-time pointing angle of a satellite. Background Technology

[0002] With the rapid development of aerospace technology, satellite communication has become an important part of the global communication network. Satellite communication is a technology that uses artificial satellites as relay stations to achieve long-distance information transmission. The principle of satellite communication is as follows: First, the transmitting ground station modulates the raw information to be transmitted (such as voice, data, or video) into a signal and sends it to the satellite; then, the antenna on the satellite captures the signal sent by the transmitting ground station and amplifies the signal through an amplifier; subsequently, the satellite transmits the amplified signal back to the receiving ground station on Earth through its antenna; finally, the receiving ground station receives the signal transmitted back by the satellite, demodulates and decodes it to restore the original information (such as voice, data, or video).

[0003] In practical applications, the signal transmission quality between a satellite and a ground station is highly correlated with the pointing angle of the satellite antenna. The pointing angle of a satellite antenna is the angle between the satellite antenna and the ground station transmitting signals to it. To obtain the pointing angle, current technologies often involve acquiring the satellite's orbital and attitude data and calculating the antenna's pointing angle at the satellite's feed time based on this data. However, the feed time and the acquisition time are not perfectly matched, resulting in the antenna pointing angle at the feed time determined based on the acquired orbital and attitude data lacking real-time accuracy.

[0004] To address the aforementioned problems, this invention provides a method and system for acquiring, calculating, and controlling the real-time pointing angle of a satellite. Summary of the Invention

[0005] The following provides a brief overview of one or more aspects to offer a basic understanding of them. This overview is not an exhaustive summary of all conceived aspects, nor is it intended to identify key or decisive elements of all aspects, nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form to prepare for the more detailed descriptions that follow.

[0006] To overcome the above-mentioned defects, the present invention aims to provide a method and control system for acquiring, calculating and controlling the real-time pointing angle of a satellite, so as to make up for the lack of real-time pointing angle of satellite antennas in the prior art.

[0007] According to one aspect of the present invention, a method for obtaining a satellite's real-time pointing angle is provided. In one embodiment, the method includes: acquiring several sets of orbit acquisition data and attitude acquisition data closest to the current feeding time, wherein the orbit acquisition data and attitude acquisition data have timestamps identifying their acquisition times; determining the orbit data and attitude data at the current feeding time based on the orbit acquisition data and attitude acquisition data; and determining the pointing angle of the satellite towards its target ground station at the current feeding time based on the orbit data and attitude data at the current feeding time, as the satellite's real-time pointing angle at the current feeding time.

[0008] Furthermore, the orbital data includes at least the satellite's position coordinates. Determining the pointing angle of the satellite towards its target ground station at the current feeding time based on the orbital and attitude data at the current feeding time includes: constructing a first pointing vector of the satellite towards the target ground station based on the satellite's position coordinates and the target ground station's position coordinates at the current feeding time; converting the first pointing vector to the satellite's own frame using the orbital and attitude data at the current feeding time to determine the own frame pointing vector corresponding to the first pointing vector in the satellite's own frame; and calculating the pointing angle using the own frame pointing vector.

[0009] Furthermore, the conversion of the first pointing vector to the satellite's own system using orbital and attitude data includes: determining a first transformation matrix from the original coordinate system to the satellite's orbital system using orbital data at the current feeding time; converting the first pointing vector to the satellite's orbital system using the first transformation matrix to obtain the orbital system pointing vector corresponding to the first pointing vector in the satellite's orbital system; determining a second transformation matrix from the satellite's orbital system to the satellite's own system using attitude data at the current feeding time; and converting the orbital system pointing vector to the satellite's own system using the second transformation matrix to obtain the own system pointing vector.

[0010] In one embodiment, the pointing angle includes azimuth and pitch angles, and the pointing vector of this system includes roll axis coordinates, pitch axis coordinates, and yaw axis coordinates; calculating the pointing angle using the pointing vector of this system includes: calculating the azimuth using phi = arctan(y / x); and calculating the azimuth using theta = arctan((x / x)). 2 +y 2 ) / z 2 Calculate the pitch angle, where x, y, and z are the roll axis coordinates, pitch axis coordinates, and yaw axis coordinates in the pointing vector of the system, respectively.

[0011] In one embodiment, the orbital data includes the satellite's linear velocity and position coordinates. Determining the first transformation matrix using the orbital data at the current feeding time includes: using... The first transformation matrix is ​​determined, where T = (T x ,Ty ,T Z ) is the first transformation matrix, v is the linear velocity of the satellite at the current feeding time, and P sat These are the satellite's position coordinates at the current power-feeding moment.

[0012] In one embodiment, the attitude data includes the satellite's angular velocity and attitude quaternions. Determining the second transformation matrix from the satellite's orbital system to its own system using the attitude data at the current feeding time includes: determining the second transformation matrix R using the attitude quaternions in the attitude data at the current feeding time.

[0013]

[0014] Among them, q1, q2, q3 and q4 are one of the attitude quaternions at the current feeding moment.

[0015] Furthermore, determining the orbital data and attitude data at the current power-feeding moment based on orbital acquisition data and attitude acquisition data respectively includes: determining the orbital data at the current power-feeding moment using an interpolation method based on orbital acquisition data; and determining the attitude data at the current power-feeding moment using an extrapolation method based on attitude acquisition data.

[0016] Furthermore, based on the track acquisition data, the track data for the current power supply time is determined using an interpolation method, which includes: obtaining the two sets of track acquisition data whose timestamps are closest to the current power supply time; and using a linear interpolation method based on the two sets of track acquisition data closest to the current power supply time to obtain the track data for the current power supply time.

[0017] Furthermore, based on the attitude acquisition data, the attitude data at the current feeding time is determined by extrapolation method, including: determining the attitude data extrapolation matrix using the time difference between the timestamp in the attitude acquisition data and the current feeding time and the angular velocity of the satellite in the attitude acquisition data; and determining the attitude quaternion at the current feeding time using the attitude data extrapolation matrix and the attitude quaternion in the attitude acquisition data.

[0018] In one embodiment, determining the attitude data extrapolation matrix using the time difference between the timestamp in the attitude acquisition data and the current feeding time, and the angular velocity of the satellite in the attitude acquisition data, includes: using... The attitude data extrapolation matrix is ​​determined, where M indicates the attitude data extrapolation matrix, W′=(w1′,w′2,w′3) represents the satellite's angular velocity in the attitude acquisition data, w1′, w′2, and w′3 are the three angular velocity components of the satellite in its roll axis, pitch axis, and yaw axis, respectively, and t is the time difference between the timestamp in the attitude acquisition data and the current feeding time; and the attitude quaternion at the current feeding time is determined using the attitude data extrapolation matrix and the attitude quaternion in the attitude acquisition data, including: using The attitude quaternion at the current feeding moment is determined, where q′1, q′2, q′3 and q′4 are one of the attitude quaternions in the attitude acquisition data; Q is the attitude quaternion at the current feeding moment; and M is the attitude data extrapolation matrix.

[0019] According to another aspect of the present invention, a method for calculating the error of a satellite's real-time pointing angle is provided. The method includes: obtaining a first pointing angle and a second pointing angle for the current feeding cycle using the aforementioned method for obtaining the satellite's real-time pointing angle, wherein the current feeding cycle starts from the previous feeding time and ends at the current feeding time, and the first pointing angle and the second pointing angle are the real-time pointing angles of the satellite at the previous feeding time and the current feeding time, respectively; calculating the theoretical pointing angle for each control cycle within the current feeding cycle based on the first pointing angle; calculating the real-time pointing angle for each control cycle within the current feeding cycle based on the first pointing angle and the second pointing angle; and calculating the error angle for each control cycle based on the theoretical pointing angle and the real-time pointing angle for each control cycle, and using the error angle for each control cycle within the current feeding cycle as the error of the current feeding cycle.

[0020] Furthermore, calculating the theoretical pointing angle for each control cycle within the current power supply cycle based on the first pointing angle includes: calculating the third pointing angle based on the first pointing angle, where the third pointing angle is the theoretical pointing angle at the current power supply moment; and determining the theoretical pointing angle for each control cycle within the current power supply cycle using interpolation based on the first and third pointing angles.

[0021] Furthermore, the process of obtaining the first and second pointing angles also includes intermediate output data, which includes orbital and attitude data at the previous feeding time and orbital data at the current feeding time. Calculating the third pointing angle based on the first pointing angle includes: extrapolating the attitude data at the current feeding time based on the attitude data at the previous feeding time; and determining the theoretical pointing angle of the satellite at the current feeding time based on the orbital and attitude data at the current feeding time, as the third pointing angle.

[0022] Optionally, the acquisition method for obtaining the first pointing angle and the second pointing angle also includes intermediate output data. The intermediate output data includes the orbital data and attitude data at the previous feeding time and the orbital data at the current feeding time. Calculating the theoretical pointing angle for each control cycle within the current feeding cycle based on the first pointing angle includes: obtaining the orbital data for each control cycle using an interpolation method based on the orbital data at the previous feeding time and the orbital data at the current feeding time; extrapolating the attitude data for each control cycle based on the attitude data at the previous feeding time; and determining the theoretical pointing angle for each control cycle within the current feeding cycle using the orbital data and attitude data of each control cycle.

[0023] According to another aspect of the present invention, a method for controlling the real-time pointing angle of a satellite is provided. The method includes: calculating the error of the current feeding cycle using the aforementioned error calculation method, wherein the error of the current feeding cycle includes the error angles of all control cycles within the current feeding cycle, and the current feeding cycle starts from the previous feeding moment and ends at the current feeding moment; determining that angle compensation is required for the current feeding cycle in response to any error angle within the current feeding cycle being greater than a first preset threshold; determining the compensation angle of each control cycle within the current feeding cycle using a linear interpolation method based on the real-time pointing angle of the previous feeding moment and the theoretical pointing angle of the current feeding moment; and sequentially using the compensation angle of each control cycle as the antenna pointing angle towards the target.

[0024] Furthermore, the satellite pointing angle control method also includes: obtaining the turntable telemetry pointing angle corresponding to the pointing angle of each antenna to the target; determining the control error of the satellite antenna based on the turntable telemetry pointing angle and the pointing angle of the antenna to the target; and reconfiguring the control relationship of the satellite antenna in response to the control error being greater than a second preset threshold.

[0025] Furthermore, the antenna pointing angle to the target includes the elevation angle and the azimuth angle. The control error is the vector angle error of the vector angle formed by the elevation angle and the azimuth angle in the antenna pointing angle to the target relative to the telemetry pointing angle of the turntable.

[0026] According to another aspect of the present invention, a control system for real-time pointing angle of a satellite is provided. The control system includes: a GNSS receiver for acquiring orbital acquisition data of the satellite; a star sensor for acquiring attitude acquisition data of the satellite; and an on-orbit pointing angle calculation module for an antenna. The on-orbit pointing angle calculation module communicates with the GNSS receiver and the star sensor respectively to acquire several sets of orbital acquisition data and attitude acquisition data closest to the current feeding time. The orbital acquisition data and attitude acquisition data have timestamps identifying their acquisition times. The on-orbit pointing angle calculation module is configured to: determine the orbital data and attitude data at the current feeding time based on the orbital acquisition data and attitude acquisition data; and determine the pointing angle of the satellite towards its target ground station at the current feeding time based on the orbital data and attitude data at the current feeding time, as the real-time pointing angle of the satellite at the current feeding time.

[0027] Furthermore, the satellite's real-time pointing angle control system also includes: an antenna theoretical pointing angle calculation module, which communicates with the antenna on-orbit pointing angle calculation module, the GNSS receiver, and the star sensor to obtain the first pointing angle of the current feeding cycle. The current feeding cycle begins at the start of the previous feeding moment and ends at the current feeding moment. The first pointing angle is the satellite's real-time pointing angle at the previous feeding moment. The antenna theoretical pointing angle calculation module is configured to calculate the theoretical pointing angle for each control cycle within the current feeding cycle based on the first pointing angle. The antenna on-orbit pointing angle calculation module is also configured to calculate the real-time pointing angle for each control cycle within the current feeding cycle based on the first pointing angle and a second pointing angle, where the second pointing angle refers to the real-time pointing angle corresponding to the current feeding moment. Finally, an antenna pointing angle comparison module communicates with both the antenna theoretical pointing angle calculation module and the antenna theoretical pointing angle calculation module to obtain the theoretical and real-time pointing angles for each control cycle. The antenna pointing angle comparison module is configured to calculate the error angle for each control cycle based on the theoretical and real-time pointing angles for each control cycle.

[0028] Furthermore, the satellite's real-time pointing angle control system also includes an angle compensation module, which communicates with an antenna pointing angle comparison module, an antenna on-orbit pointing angle calculation module, and an antenna theoretical pointing angle calculation module to obtain the error angle of each control cycle within the current feeding cycle, the real-time pointing angle at the previous feeding moment, and the theoretical pointing angle at the current feeding moment, respectively. The angle compensation module is also configured to: determine that angle compensation is needed for the current feeding cycle in response to any error angle within the current feeding cycle being greater than a first preset threshold; determine the compensation angle for each control cycle within the current feeding cycle using a linear interpolation method based on the real-time pointing angle at the previous feeding moment and the theoretical pointing angle at the current feeding moment; and sequentially use the compensation angle of each control cycle as the antenna pointing target angle.

[0029] Furthermore, the satellite real-time pointing angle control system also includes: a servo controller, which communicates with the angle compensation module to obtain the antenna pointing target angle, and is configured to output control information to control the satellite antenna's steering; a turntable position telemetry module, which communicates with the servo controller to obtain control information, and is configured to obtain the turntable telemetry pointing angle corresponding to each antenna pointing target angle; and a turntable position telemetry comparison module, which communicates with the angle compensation module and the turntable position telemetry module to obtain the antenna pointing target angle and the turntable telemetry pointing angle corresponding to each antenna pointing target angle, and is configured to determine the satellite antenna's control error based on the turntable telemetry pointing angle and the antenna pointing target angle; and reconfigure the satellite antenna's control relationship in response to the control error exceeding a second preset threshold.

[0030] According to another aspect of the present invention, a control device for real-time satellite pointing angle is also provided, comprising a plurality of memories, a plurality of processors, and a computer program stored in the memories. The plurality of memories and processors include a first memory and a first processor. When the first processor executes the computer program stored in the first memory, it implements the steps of the method for obtaining the real-time satellite pointing angle as described in any of the foregoing embodiments. In one embodiment, the plurality of memories and processors in the control device further include a second memory and a second processor. When the second processor executes the computer program stored in the second memory, it implements the steps of the method for calculating the error of the real-time satellite pointing angle as described in any of the foregoing embodiments. In one embodiment, the plurality of memories and processors in the control device further include a third memory and a third processor. When the third processor executes the computer program stored in the third memory, it implements the steps of the method for controlling the satellite pointing angle as described in any of the foregoing embodiments.

[0031] According to another aspect of the present invention, a computer storage medium is also provided, on which a computer program is stored. When the computer program is executed, it implements a method for obtaining the real-time pointing angle of a satellite, an error calculation method, and a method for controlling the pointing angle of a satellite. The method for obtaining the real-time pointing angle of a satellite is the method for obtaining the real-time pointing angle of a satellite in any of the foregoing embodiments, the error calculation method for the real-time pointing angle of a satellite is the error calculation method for the real-time pointing angle of a satellite in any of the foregoing embodiments, and the method for controlling the pointing angle of a satellite is the method for controlling the pointing angle of a satellite in any of the foregoing embodiments.

[0032] The present invention provides a method and system for acquiring, calculating and controlling the real-time pointing angle of a satellite. It accurately acquires the real-time pointing angle of the satellite at the time of power-up, and performs error calculation and compensation control on the real-time pointing angle of the satellite based on the acquired real-time pointing angle, so that the real-time pointing angle of the satellite antenna is consistent with the theoretical pointing angle, thereby achieving good signal transmission quality between the satellite and the target ground station. Attached Figure Description

[0033] The above-described features and advantages of the present invention will be better understood after reading the detailed description of the embodiments of this disclosure in conjunction with the following accompanying drawings.

[0034] Figure 1 This is a schematic diagram of a satellite orbiting in orbit.

[0035] Figure 2 A flowchart illustrating the steps of a method for obtaining the real-time pointing angle of a satellite according to one aspect of the present invention.

[0036] Figure 3 This is a flowchart illustrating the steps involved in determining the orbital data at the current power-feeding moment using the angular velocity extrapolation method as an example.

[0037] Figure 4 This is a flowchart illustrating the steps of determining the pointing angle of a satellite toward its target ground station at the current power-on time based on orbital and attitude data at the current power-on time, as a specific embodiment.

[0038] Figure 5 This is a flowchart illustrating the steps for calculating the pointing angle using the pointing vector of this system in some embodiments.

[0039] Figure 6 A flowchart illustrating a method for calculating the error of a satellite's real-time pointing angle in a specific embodiment provided according to another aspect of the present invention.

[0040] Figure 7 A flowchart illustrating a method for controlling the real-time pointing angle of a satellite according to a specific embodiment of another aspect of the present invention.

[0041] Figure 8 This is a flowchart illustrating the verification process in a satellite real-time pointing angle control method according to one embodiment.

[0042] Figure 9 A structural block diagram of a satellite pointing angle control system according to another aspect of the present invention.

[0043] Figure 10 A simplified schematic diagram of a satellite real-time pointing angle control device according to another aspect of the present invention. Detailed Implementation

[0044] The following description is provided to enable those skilled in the art to implement and use the invention and adapt it to specific application contexts. Various modifications and uses in different applications will be readily apparent to those skilled in the art, and the general principles defined herein are applicable to a wide range of embodiments. Therefore, the invention is not limited to the embodiments given herein, but should be granted the broadest scope consistent with the principles and novel features disclosed herein.

[0045] In the following detailed description, numerous specific details are set forth to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that practice of the invention is not necessarily limited to these specific details. In other words, well-known structures and devices are shown in block diagram form without being depicted in detail to avoid obscuring the invention.

[0046] Readers should note all documents and references submitted concurrently with this specification and open to public inspection, the contents of which are incorporated herein by reference. Unless otherwise expressly stated, all features disclosed in this specification (including any appended claims, abstracts, and drawings) may be replaced by alternative features for the same, equivalent, or similar purposes. Therefore, unless explicitly stated otherwise, each disclosed feature is merely one example of a set of equivalent or similar features.

[0047] Note that, where used, the markings left, right, front, back, top, bottom, front, back, clockwise, and counterclockwise are merely for convenience and do not imply any specific fixed direction. In fact, they are used to reflect the relative position and / or orientation between different parts of an object. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0048] Note that, in practice, "further," "preferably," "even further," and "more preferably" are simply starting points for describing another embodiment based on the foregoing embodiments. The combination of the content following "further," "preferably," "even further," or "more preferably" with the foregoing embodiments constitutes the complete configuration of another embodiment. Any combination of several "further," "preferably," "even further," or "more preferably" settings following the same embodiment can form yet another embodiment.

[0049] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. It should be noted that the aspects described below with reference to the accompanying drawings and specific embodiments are merely exemplary and should not be construed as limiting the scope of protection of the present invention in any way.

[0050] Common reference coordinate systems used in calculating satellite pointing angles include: the Earth-centered Earth-fixed system, the satellite orbital system, and the satellite's own system.

[0051] The Earth-centered Earth-fixed system is a three-dimensional rectangular coordinate system with the Earth's center of mass as the origin and coordinate axes defined along the Earth's equatorial plane. It is commonly used to describe the precise location of a point on Earth. Typically, the X-axis of the Earth-centered Earth-fixed system points from the Earth's center of mass to the intersection of the equator and the 0° longitude line within the equatorial plane; the Y-axis points from the Earth's center of mass to the intersection of the equator and the 90° east longitude line within the equatorial plane; and the Z-axis is perpendicular to the equatorial plane, pointing from the Earth's center of mass to the Earth's North Pole.

[0052] A satellite orbital system is a three-dimensional Cartesian coordinate system with the satellite's center of mass as the origin and the coordinate axes defined along the orbital plane. It is commonly used to describe the trajectory of a satellite in space. Typically, the X-axis of the satellite orbital system lies in the orbital plane and points in the direction of the satellite's motion; the Y-axis lies in the orbital plane and points in the direction of the Earth's center of mass; and the Z-axis is perpendicular to the orbital plane and forms a right-handed Cartesian coordinate system with the X and Y axes.

[0053] The satellite system is a three-dimensional Cartesian coordinate system with the satellite's center of mass as the origin and coordinate axes defined along the plane of the satellite's own physical structure. It is commonly used to describe the satellite's attitude and the relative positions of its various components.

[0054] Figure 1 This is a schematic diagram of a satellite orbiting the Earth. (For example...) Figure 1 As shown, the ground facility located on the Earth's surface that transmits signals to the satellite is the target ground station 11. The trajectory of the satellite 12 orbiting the Earth is orbit 13. The satellite 12 is equipped with an antenna turntable 121 and a satellite antenna 122. (Refer to...) Figure 1It can be understood that if the antenna turntable mounting surface 123 is used as the reference surface to establish the satellite system, then the Z-axis direction of the satellite system is the direction from the satellite's center of mass to the Earth's center of mass and perpendicular to the antenna turntable mounting surface 123; the X-axis direction of the satellite system is the direction from the satellite's center of mass to the direction of the satellite's motion and parallel to the antenna turntable mounting surface 123; and the Y-axis direction of the satellite system is perpendicular to the X-axis of the satellite system and parallel to the antenna turntable mounting surface 123. The X-axis, Y-axis, and Z-axis of the satellite system are usually referred to as the azimuth axis, elevation axis, and yaw axis, respectively.

[0055] A satellite's pointing angle typically includes azimuth and elevation. Azimuth refers to the angle by which the satellite rotates around its azimuth axis (X-axis), and elevation refers to the angle by which the satellite rotates around its elevation axis (Y-axis). During operation, the satellite antenna 122 rotates with the antenna turntable 121, resulting in the antenna antenna 122's orientation angle not always being perpendicular to the turntable mounting surface 123. The satellite's pointing angle is the angle between the antenna's orientation angle and the yaw axis (Z-axis in the diagram) within the satellite's system. It can be understood that since the satellite's pointing angle is referenced to the yaw axis (Z-axis) within its system, determining the azimuth and elevation angles is sufficient to determine the satellite's pointing angle.

[0056] According to one aspect of the present invention, a method for obtaining the real-time pointing angle of a satellite is provided. The real-time pointing angle of the satellite refers to the angle between the satellite's pointing device and the yaw axis in the satellite's system at any given time. This method for obtaining the real-time pointing angle of a satellite can be used to obtain the real-time pointing angle of a satellite's antenna, sensor, or other pointing device.

[0057] It is understood that this application describes the method and its corresponding system in combination to enable those skilled in the art to better understand the technical concept of the present invention.

[0058] Figure 2 This diagram illustrates the steps of a method for obtaining the real-time pointing angle of a satellite in one embodiment. (Refer to...) Figure 2 The method for obtaining the real-time pointing angle may include the following steps S21 to S23.

[0059] Step S21 involves acquiring several sets of orbit acquisition data and attitude acquisition data that are closest to the current power supply time. The orbit acquisition data and attitude acquisition data each have a timestamp identifying their acquisition time.

[0060] The feed time refers to the specific point in time when the satellite transmits data with its target ground station. This data transmission can be either sending or receiving data. The current feed time refers to the feed time during which the pointing angle calculation, identification, or determination is being performed; it is typically the time of the most recent data transmission between the satellite and the ground station.

[0061] A timestamp refers to the time information recorded by a satellite when it is collecting data.

[0062] Orbital acquisition data refers to information data collected by acquisition equipment that describes the trajectory and motion state of a satellite in space, including but not limited to the satellite's position coordinates, linear velocity, orbital parameters, and acquisition time. In this embodiment of the invention, each set of orbital acquisition data includes at least the satellite's position coordinates, linear velocity, and a timestamp indicating the acquisition time of the data, depending on the calculation requirements.

[0063] The satellite's position coordinates can be based on existing or future universal position coordinate systems such as geocentric inertial coordinate systems, geocentric-ground-fixed coordinate systems, orbital coordinate systems, and horizontal coordinate systems. Preferably, the coordinate system used by a satellite positioning system, such as the coordinate system used by GNSS (Global Navigation Satellite System) equipment, can be adopted. Global Navigation Satellite Systems include, but are not limited to, one or more existing or future satellite positioning systems such as the BeiDou Navigation Satellite System, the GLONASS Global Positioning System, and the Galileo Satellite Navigation System.

[0064] The linear velocity of a satellite refers to its velocity along the tangent to its orbit, and can usually be expressed as the velocity components along the three coordinate axes of the coordinate system in which it is used.

[0065] Those skilled in the art will understand that orbital data can be acquired using existing or future methods capable of satellite orbital data acquisition, such as ground station tracking and measurement, spaceborne sensor measurement and acquisition, optical observation and acquisition, or laser communication acquisition. A simpler approach is to acquire satellite orbital data using GNSS equipment installed on the satellite.

[0066] Attitude acquisition data refers to information data collected by acquisition equipment that describes the orientation and attitude state of a satellite in space. It typically includes satellite attitude quaternions, angular velocity, attitude control data, and acquisition time. In this embodiment of the invention, depending on computational needs, the attitude acquisition data includes at least the satellite's attitude quaternions, angular velocity, and a timestamp indicating the acquisition time of this data.

[0067] Among them, the satellite's attitude quaternion is a four-dimensional complex number that describes the satellite's rotational state in three-dimensional space. It typically includes a real part representing the rotational scalar part and three imaginary parts representing the rotational vector part.

[0068] The angular velocity of a satellite is a physical quantity that represents how fast a satellite rotates around its rotation axis. It can usually be expressed as three angular velocity components on the satellite's roll axis, pitch axis, and yaw axis.

[0069] Those skilled in the art will understand that satellite attitude acquisition data can be collected using sensors on the satellite capable of acquiring attitude data, such as star sensors, solar sensors, geomagnetic sensors, or inertial measurement sensors. Alternatively, satellite attitude data can also be acquired using observation-based attitude data acquisition methods, such as radar observation or optical observation. The sets of orbit acquisition data closest to the current feeding time refer to the sets of orbit acquisition data with the shortest time interval between the timestamp and the current feeding time. These sets can be set to one or more sets depending on the calculation method required.

[0070] The sets of attitude acquisition data closest to the current power-up time refer to the sets of attitude acquisition data with the shortest time interval between the timestamp and the current power-up time. These sets can be set to one or more sets depending on the calculation method.

[0071] Step S22: Determine the orbit data and attitude data at the current power feeding moment based on the orbit acquisition data and attitude acquisition data, respectively.

[0072] It is understandable that the acquired orbit and attitude data have a set acquisition period, which is usually related to the performance and settings of the acquisition equipment. The satellite's power-on time, however, is related to its communication period with the ground station. It is difficult for the acquisition periods of different acquisition devices, or the communication periods between different acquisition devices and the satellite, to perfectly correspond. This misalignment between acquisition time and communication time results in an objective time discrepancy when directly using the acquired orbit and attitude data to calculate the satellite's pointing angle, leading to insufficient real-time performance. Therefore, this invention utilizes the acquired orbit and attitude data to deduce the orbit and attitude data at the power-on time, and then uses the deduced orbit and attitude data to calculate the satellite's pointing angle at the power-on time. This reduces the time discrepancy between data acquisition time and satellite communication time, significantly mitigating the problem of insufficient real-time performance of the pointing angle in existing satellite systems.

[0073] Those skilled in the art will understand that, based on orbit acquisition data, orbit data at the current feeding time can be determined using interpolation or extrapolation methods. Extrapolation methods for orbit data may include existing or future methods capable of satellite orbit estimation, such as Keplerian extrapolation or numerical integral extrapolation; interpolation methods for orbit data may include existing or future methods capable of interpolating satellite orbit data, such as polynomial interpolation, spline interpolation, nearest neighbor interpolation, piecewise linear interpolation, or Kriging interpolation.

[0074] Preferably, in one specific embodiment, the two sets of track acquisition data whose timestamps are closest to the current power supply time can be obtained from the track acquisition data, and the track data at the current power supply time can be obtained by linear interpolation based on the two sets of track acquisition data closest to the current power supply time, so as to reduce the amount of calculation and reduce the calculation time.

[0075] Those skilled in the art will understand that, based on attitude acquisition data, the attitude data at the current power-feeding moment can be determined using extrapolation methods. Examples include extrapolation based on angular velocity, extrapolation based on dynamic models, extrapolation based on filtering algorithms, or polynomial fitting extrapolation.

[0076] Preferably, in one specific embodiment, a set of attitude acquisition data with the timestamp closest to the current power-feeding time can be obtained, and the orbital data at the current power-feeding time can be calculated using the angular velocity extrapolation method, so as to reduce the computational complexity.

[0077] Figure 3 This diagram illustrates the steps involved in determining the orbital data at the current power-feeding moment using the angular velocity extrapolation method as an example. Figure 3 As shown, the steps to determine the attitude data at the current power-feeding moment using attitude acquisition data can be further refined into steps S221 and S222.

[0078] Step S221 involves determining the attitude data extrapolation matrix using the time difference between the timestamp in the attitude acquisition data and the current feeding time, as well as the angular velocity of the satellite in the attitude acquisition data.

[0079] The attitude data extrapolation matrix is ​​determined using the following equation (1):

[0080]

[0081] Where t is the time difference between the timestamp of the attitude acquisition data and the current power-on time, W′=(w1′,w′2,w′3) is the angular velocity of the satellite in the attitude acquisition data, and w1′, w′2 and w′3 are the three angular velocity components of the satellite in its roll axis, pitch axis and yaw axis directions, respectively.

[0082] Step S222 is: Determine the attitude quaternion at the current feeding moment using the attitude data extrapolation matrix and the attitude quaternion in the attitude acquisition data.

[0083] The attitude quaternion at the current feeding moment is determined using the following equation (2):

[0084]

[0085] Where q′1, q′2, q′3, and q′4 are attitude quaternions in the attitude acquisition data, M is the attitude data extrapolation matrix, Q = (q1, q2, q3, q4) is the attitude quaternion at the current feeding moment, and q1, q2, q3, and q4 are attitude quaternions at the current feeding moment.

[0086] Furthermore, after determining the orbital and attitude data at the current feeding time, step S23 is: determining the pointing angle of the satellite towards its target ground station at the current feeding time based on the orbital and attitude data at the current feeding time. This pointing angle can be used as the satellite's real-time pointing angle at the current feeding time.

[0087] It is understandable that after determining the orbital and attitude data at the current feeding moment, all data can be unified to the satellite's own coordinate system through coordinate system transformations. Then, the pointing vector of the satellite pointing to its target ground station within its own coordinate system can be used to determine the pointing angle. In this process, the position data can be first transformed to the satellite's orbital system using coordinate system transformations, then the pointing vector of the satellite pointing to the target ground station can be constructed, and then this pointing vector can be transformed to the satellite's own coordinate system. Alternatively, the pointing vector of the satellite pointing to the target ground station based on the coordinate system of the orbital data can be constructed first, and then this pointing vector can be transformed to the satellite's own coordinate system via the satellite's orbital system.

[0088] Taking the construction of a pointer vector as an example, Figure 4 A flowchart illustrating the steps of determining the pointing angle of a satellite toward its target ground station at the current feeding time, based on orbital and attitude data at the current feeding time, is shown in a specific embodiment. Figure 4 As shown, step S23 may include steps S231 to S233.

[0089] Step S231 involves constructing a first pointing vector from the satellite to the target ground station based on the satellite's position coordinates at the current power-on time and the target ground station's position coordinates. The orbital data includes at least the satellite's position coordinates.

[0090] It is understandable that the target ground station is fixed on the Earth, so its position remains unchanged relative to the Earth and can be represented using existing conventional coordinate systems, such as the geocentric coordinate system, the geocentric inertial coordinate system, and the equatorial coordinate system. Preferably, the position of the target ground station can be represented using the original coordinate system used by the satellite orbit data acquisition equipment, so as to establish the first pointing vector within the same coordinate system.

[0091] Those skilled in the art will understand that when the coordinate system used for the position coordinates of the target ground station is different from the original coordinate system used by the satellite orbit data acquisition equipment, the position coordinates of the target ground station and the position coordinates of the satellite can be unified to the same coordinate system through coordinate system transformation, and then a pointing vector from the satellite to the target ground station, i.e., the first pointing vector, can be established.

[0092] For example, when the reference coordinate system of the target ground station's position coordinates is the 84 coordinate system and the original coordinate system of the satellite's position coordinates is the geocentric coordinate system, the position coordinates of the target ground station can be transformed to the geocentric coordinate system using the following formula (3).

[0093] Let the coordinates of the target ground station be... Then the position coordinates in the 84 coordinate system The position coordinates P in the geocentric-geocentric coordinate system can be transformed using the following formula (3). e (X s Y s Z s ):

[0094]

[0095] Where N is the radius of curvature of the ellipsoid. 'a' is the semi-axis length of the ellipsoid. In the WGS-84 coordinate system, the semi-axis length of the ellipsoid is 6,378,137 meters. 'e' is... 2 The square of the first eccentricity of the ellipsoid is 0.00669437999014.

[0096] For example, once the position coordinates of the target ground station and the satellite are unified to the same coordinate system, the difference method can be used to construct the first pointing vector from the satellite to the target ground station. Assume the position coordinates of the target ground station in the Earth-centered Earth-fixed coordinate system are P. e =(X s Y s Z s The satellite's position coordinates in the Earth-centered Earth-fixed coordinate system at the current power-feeding moment are P. sat = (X, Y, Z), then the first pointing vector can be represented as: P1 = (X s -X, Y s -Y, Z s -Z).

[0097] It is understood that those skilled in the art can also use common methods for constructing pointing vectors, such as the unit vector method, vector projection method, or geometric construction method, to construct the first pointing vector.

[0098] Step S232 involves converting the first pointing vector to the satellite's own frame using the orbital and attitude data at the current feeding moment. This step is used to determine the own frame pointing vector corresponding to the first pointing vector in the satellite's own frame.

[0099] Understandably, positioning systems commonly used to collect satellite orbital data typically employ a coordinate system with the Earth's center of mass as its origin. This coordinate system ignores the Earth's own motion. Orbital data is used to transform the Earth-centered coordinate system into a satellite orbital system, thereby determining the satellite's trajectory in space. After determining the satellite's trajectory using orbital data, the satellite's attitude data is then used to transform the orbital system back into the satellite's intrinsic system, further determining the satellite's attitude in space.

[0100] Figure 5 A flowchart illustrating the steps for calculating the pointing angle using the pointing vector of this system in some embodiments is shown. (Refer to...) Figure 5 In one specific embodiment, step S232 can be further refined into steps S2321-S2324.

[0101] Step S2321: Determine the first transformation matrix from the original coordinate system to the satellite orbit system using the orbit data at the current feeding time.

[0102] It is understandable that orbital data often uses a coordinate system with the Earth's center of mass as the origin. This coordinate system ignores the Earth's rotation. However, after the transformation to the satellite orbital system, the Earth's rotation cannot be ignored. Therefore, in the process of transforming these coordinate systems with the Earth's center of mass as the origin to the satellite orbital system, it is necessary to correct the satellite velocity and thus determine the first transformation matrix.

[0103] In one specific embodiment, the reference coordinate system for the orbital data is the geocentric-ground-fixed coordinate system. The linear velocity based on the geocentric-ground-fixed coordinate system can be converted to the satellite orbital system using the following equation (4):

[0104]

[0105] Where ω is the angular velocity of the Earth's rotation, which is 7.292 * 10⁻⁶. -5 rad / s; v′ x v′ y and v′ z These are the three velocity components of the satellite's linear velocity in its orbital system with the Earth's center of mass as the origin; v x v y and v z These are the three velocity components of the satellite's linear velocity in its orbital system; X s and Y s These are the X-axis and Y-axis coordinates of the target ground station in the Earth-centered Earth-fixed coordinate system.

[0106] After correcting the satellite linear velocity to the satellite linear velocity with the satellite orbital system as the reference coordinate system, then using... The first transformation matrix is ​​determined, where T = (T x ,T y ,T z ) is the first transformation matrix, v is the satellite linear velocity at the current feeding moment, and P sat These are the satellite's position coordinates at the current power-feeding moment.

[0107] It should be noted that the foregoing examples illustrate the specific conversion method for transforming the reference coordinate system of the orbital data at the current power-feeding time from the geocentric inertial coordinate system to the satellite orbital coordinate system. In actual implementation, due to the different reference coordinate systems used by the orbital data acquisition equipment, the coordinate system of the obtained orbital data at the current power-feeding time will also be different. Therefore, the specific conversion process may differ in different embodiments. The purpose of step S321 is to transform the orbital data at the current power-feeding time from its used coordinate system to the satellite orbital system. This invention does not limit the actual coordinate system used for the orbital data. The coordinate system of the orbital data at the current power-feeding time can be a common coordinate system such as the geocentric inertial coordinate system or the equatorial coordinate system. The conversion methods from common coordinate systems to satellite orbital systems are well known to those skilled in the art and will not be listed one by one in the embodiments here.

[0108] Step S2322 involves transforming the first pointing vector to the satellite orbital system using the first transformation matrix. This step is used to obtain the orbital system pointing vector corresponding to the first pointing vector in the satellite orbital system.

[0109] Taking the aforementioned example of the transformation from the Earth-centered Earth-fixed coordinate system to the satellite orbital system, after constructing the first pointing vector P1 and the first transformation matrix T, the orbital system pointing vector P2 corresponding to the first pointing vector P1 can be obtained by P1*T=P2.

[0110] Step S2323: Determine the second transformation matrix from the satellite orbital system to the satellite body system using the attitude data at the current feeding time.

[0111] The difference between a satellite orbital system and a satellite intrinsic system lies in the plane on which the coordinate axes are defined. The coordinate axes of a satellite orbital system are defined along the plane of the satellite's orbit, while the coordinate axes of a satellite intrinsic system are defined along the plane of the satellite's own physical structure (such as the plane of a solar panel or the pointing plane of an antenna). Therefore, the satellite orbital system treats the satellite as a point mass, describing its trajectory in space while ignoring its attitude. A second transformation matrix is ​​constructed using attitude data to further determine the satellite's attitude, thus determining the precise state of its motion.

[0112] Assuming the attitude quaternion at the current feeding moment is Q = (q1, q2, q3, q4), the second transformation matrix R can be determined by the following equation (5):

[0113]

[0114] Among them, q1, q2, q3 and q4 are attitude quaternions of the attitude data at the current feeding moment.

[0115] Step S2324: Use the second transformation matrix to transform the orbital system pointing vector to the satellite's own system. This step is used to obtain the own system pointing vector.

[0116] Taking the aforementioned orbital pointing vector P2 and the second transformation matrix R as an example, the home system pointing vector P3(x, y, z) corresponding to the first pointing vector can be obtained by R*P2=P3, where x, y and z are the roll axis coordinate, pitch axis coordinate and yaw axis coordinate of the home system pointing vector, respectively.

[0117] Furthermore, after converting the first pointing vector to the satellite's own system using the orbital and attitude data at the current feeding moment, step S233 is: calculating the pointing angle using the pointing vector of the own system.

[0118] Specifically, the pointing angle of the satellite can be calculated using the pointing vector of this system based on the geometric relationship method.

[0119] The pointing angle of a satellite includes azimuth and elevation. Assuming the pointing vector of our system is P3(x, y, z), the azimuth can be calculated using phi = arctan(y / x), and the elevation angle can be calculated using theta = arctan((x / z)). 2 +y 2 ) / z 2 Calculate the elevation angle, where phi represents the azimuth angle of the satellite and theta represents the elevation angle of the satellite.

[0120] It is understood that those skilled in the art can also use existing or future methods for calculating satellite pointing angles, such as the spherical coordinate system method or the vector projection method, to calculate the pointing angle of a satellite.

[0121] Figure 9 A structural block diagram of a satellite pointing angle control system in one embodiment is shown. Figure 9As shown, in some embodiments, the control system for the real-time satellite pointing angle corresponding to the satellite real-time pointing angle acquisition method in any of the foregoing embodiments may include a GNSS receiver 1, a star sensor 2, and an antenna on-orbit pointing angle calculation module 4. The GNSS receiver 1 is used to acquire satellite orbit acquisition data, and the star sensor 2 is used to acquire satellite attitude acquisition data. The antenna on-orbit pointing angle calculation module 4 communicates with the GNSS receiver 1 and the star sensor 2 respectively to obtain several sets of orbit acquisition data and attitude acquisition data closest to the current feeding time. The antenna on-orbit pointing angle calculation module 4 is configured to implement the steps of the real-time pointing angle acquisition method in any of the foregoing embodiments.

[0122] In one embodiment, the communication between the GNSS receiver 1 and star sensor 2 and the on-orbit pointing angle calculation module 4 of the satellite real-time pointing angle control system may include direct communication and indirect communication. For example, in Figure 9 In the embodiment shown, the GNSS receiver 1 and the star sensor 2 communicate indirectly with the antenna on-orbit pointing angle calculation module 4 through the carrier tube 3.

[0123] The real-time pointing angle of the satellite determined in any of the foregoing embodiments is often used to determine the target pointing angle of the satellite antenna in order to control the satellite antenna and ensure good signal transmission quality of the satellite.

[0124] According to another aspect of the present invention, a method for calculating the error of a satellite pointing angle is also provided. The error of the satellite pointing angle refers to the error between the real-time pointing angle of the satellite and its theoretical pointing angle. Those skilled in the art will understand that by judging the error between the real-time and theoretical pointing angles of the satellite, the correctness of the target pointing angle of the satellite antenna can be verified, and it is convenient to make corrections and compensations when the target pointing angle is incorrect.

[0125] Figure 6 A flowchart illustrating the error calculation method for the satellite pointing angle in a specific embodiment is shown. Figure 6 As shown, the error calculation method for the real-time pointing angle of a satellite may include steps S61 to S64.

[0126] Step S61 is: obtain the first pointing angle and the second pointing angle of the current power supply cycle.

[0127] Satellite antenna control is highly precise with short control cycles. However, the time required for satellite communication activities is much longer than the antenna control cycle. Therefore, one satellite feeding cycle may encompass multiple antenna control cycles. For ease of understanding, this application defines the time interval between two feeding moments as a feeding cycle, the time interval between the execution moments of two target pointing angles of the satellite antenna as a control cycle, and the current feeding cycle as the feeding cycle containing the feeding moment corresponding to the real-time pointing angle used to determine the next target pointing angle of the satellite antenna. To correspond with the concept in the aforementioned method for obtaining the real-time pointing angle, the current feeding cycle can be considered as the current feeding moment traced back to its previous feeding moment, i.e., from the beginning of the previous feeding moment to the end of the current feeding moment.

[0128] The step duration of the power supply cycle and the control cycle is determined by the satellite's physical equipment and its configuration program, and is not limited here.

[0129] The first pointing angle refers to the starting time of the current power supply cycle, that is, the real-time pointing angle corresponding to the previous power supply time.

[0130] The second pointing angle refers to the end time of the current power supply cycle, that is, the real-time pointing angle corresponding to the current power supply time.

[0131] Preferably, the first and second pointing angles of the current power supply cycle can be obtained by the satellite real-time pointing angle acquisition method in any of the foregoing embodiments.

[0132] Step S62: Calculate the theoretical pointing angle for each control cycle within the current power supply cycle based on the first pointing angle.

[0133] The control cycle can be derived from the power supply cycle by dividing it into steps. For example, the duration of the power supply cycle is n, and the duration of the control cycle is m, where n is an integer multiple of m. In one specific embodiment, the duration of the power supply cycle is set to 250ms, and the duration of the control cycle is set to 25ms, then one power supply cycle includes 10 control cycles.

[0134] It is understood that when obtaining the first and second pointing angles in step S61 using the satellite real-time pointing angle acquisition method in any of the foregoing embodiments, intermediate output data is also included. The intermediate output data may include the orbit data and attitude data at the previous power-on time and the orbit data at the current power-on time.

[0135] In some embodiments, the calculation steps for calculating the theoretical pointing angle of each control cycle within the current power supply cycle based on the first pointing angle can be as follows: calculating the third pointing angle based on the first pointing angle, where the third pointing angle is the theoretical pointing angle at the current power supply moment; and determining the theoretical pointing angle of each control cycle within the current power supply cycle using interpolation based on the first pointing angle and the third pointing angle.

[0136] Furthermore, calculating the third pointing angle based on the first pointing angle also includes: extrapolating the attitude data at the current feeding time based on the attitude data at the previous feeding time; and determining the theoretical pointing angle of the satellite at the current feeding time based on the orbit data and attitude data at the current feeding time, as the third pointing angle.

[0137] Specifically, the attitude data at the current feeding moment can be extrapolated from the attitude data at the previous feeding moment. Using the satellite's angular velocity at the previous feeding moment and the time difference between the previous feeding moment and the current feeding moment, the attitude data extrapolation matrix from the previous feeding moment to the current feeding moment can be determined (according to equation (1)). Then, using this attitude data extrapolation matrix and the attitude quaternion at the previous feeding moment, the attitude quaternion at the current feeding moment can be calculated, thus obtaining the attitude data at the current feeding moment. The theoretical pointing angle at the current feeding moment can be calculated based on the orbital data and attitude data at the current feeding moment. The orbital data at the current feeding moment is the process data in the calculation of the second pointing angle, and can be considered as known data here. From the extrapolated attitude data at the current feeding moment and the known orbital data at the current feeding moment, the theoretical pointing angle at the current feeding moment, i.e., the third pointing angle, can be obtained.

[0138] Furthermore, based on the first and third pointing angles, the theoretical pointing angle for each control cycle within the current power supply cycle is determined using interpolation. The theoretical pointing angle for each control cycle is obtained by linear interpolation between the real-time pointing angle (first pointing angle) at the previous power supply moment and the theoretical pointing angle (third pointing angle) at the current power supply moment.

[0139] For example, assuming the current power supply cycle is [T1, T2], the control cycles within the current power supply cycle can include times such as T1+t0, T1+2t0, ..., T1+nt0, where n = (T2-T1) / t0, t0 is the step time length of the control cycle, and n is a positive integer. Then, the theoretical pointing angle of any control cycle T1+it0 (i∈[1,n]) is... The real-time pointing angle at the previous feeding time can be used as a reference. (First pointing angle) and theoretical pointing angle at the current feeding moment The interpolation of (third pointing angle) is obtained, that is

[0140] Optionally, in some embodiments, the calculation step of calculating the theoretical pointing angle of each control cycle within the current feeding cycle based on the first pointing angle can also be as follows: based on the orbit data at the previous feeding time and the orbit data at the current feeding time, the orbit data of each control cycle is obtained by interpolation; the attitude data of each control cycle is extrapolated based on the attitude data at the previous feeding time; and the theoretical pointing angle of each control cycle within the current feeding cycle is determined using the orbit data and attitude data of each control cycle.

[0141] Specifically, the process of obtaining orbit data for each control cycle using interpolation is as follows: when the satellite is running along its preset orbit, all orbit acquisition data on that orbit can be used as known data. Therefore, the orbit data for each control cycle can be obtained by interpolation from the known orbit acquisition data, or by interpolation from the orbit data at the previous feeding moment in the current feeding cycle and the orbit data at the current feeding moment.

[0142] The process of extrapolating the attitude data for each control cycle based on the attitude data at the previous feeding time is as follows: The attitude data for the first control cycle in the current feeding cycle can be extrapolated from the attitude data at the previous feeding time. The attitude data extrapolation matrix from the previous feeding time to the first control cycle can be determined using the satellite's angular velocity at the previous feeding time and the time difference between the previous feeding time and the first control cycle (according to equation (1)). The attitude quaternion for the first control cycle is calculated using the attitude data extrapolation matrix and the attitude quaternion at the previous feeding time, thus obtaining the attitude data for the first control cycle. The attitude data for the second control cycle in the current feeding cycle is extrapolated from the attitude data of the first control cycle, and so on, to calculate the attitude data for each control cycle in the current feeding cycle.

[0143] Taking the aforementioned arbitrary control period T1+it0 (i∈[1,n]) as an example, we can illustrate how to deduce the attitude data corresponding to the control period T1+it0 (i∈[1,n]) from the attitude data of the previous power feeding moment or the attitude data of the previous control period.

[0144] The attitude data extrapolation matrix is ​​calculated using the angular velocity of the previous feeding time T1 and the time difference between the previous feeding time T1 and the control period T1+it0 (according to equation (1), the attitude data extrapolation matrix from the previous feeding time T1 to the control period T1+it0 is only related to the time difference between the two and the angular velocity of the previous feeding time T1); then the attitude data extrapolation matrix and the attitude quaternion of the previous feeding time T1 are used to deduce the attitude quaternion of the control period T1+it0.

[0145] Optionally, the attitude data extrapolation matrix is ​​calculated using the angular velocity and time difference t0 at the time of the previous control period T1+(i-1)t0 (the time difference between the previous control period T1+(i-1)t0 and the control period T1+it0). According to Equation (1), the attitude data extrapolation matrix from the time of the previous control period T1+(i-1)t0 to the control period T1+it0 is only related to the time difference between the two and the angular velocity at the time of the previous control period T1+(i-1)t0. Then, the attitude quaternion of the control period T1+it0 is calculated using the attitude data extrapolation matrix and the attitude quaternion at the time of the previous control period T1+(i-1)t0.

[0146] Step S63: Calculate the real-time pointing angle for each control cycle within the current power supply cycle based on the first pointing angle and the second pointing angle. Specifically, a linear interpolation method can be used to obtain the real-time pointing angle for each control cycle based on the first pointing angle and the second pointing angle. Taking the aforementioned arbitrary control cycle T1+it0 (i∈[1,n]) as an example, in, Let be the real-time pointing angle at any control period T1+it0 (i∈[1,n]). The second pointing angle, This is the first pointing angle.

[0147] Those skilled in the art will understand that the real-time pointing angle for each control cycle can also be obtained through existing or future interpolation methods such as polynomial interpolation, spline interpolation, nearest neighbor interpolation, piecewise linear interpolation, or Kriging interpolation.

[0148] Step S64: Calculate the error angle of each control cycle based on the theoretical pointing angle and the real-time pointing angle of each control cycle, and take the error angle of each control cycle in the current power supply cycle as the error of the current power supply cycle.

[0149] Specifically, the error angle of each control cycle can be obtained by subtracting the real-time pointing angle from the theoretical pointing angle. In a specific embodiment, for ease of judgment, the error angle of each control cycle can be taken as the absolute value of the difference between the real-time pointing angle and the theoretical pointing angle of that control cycle.

[0150] like Figure 9 As shown, corresponding to the steps of the error calculation method in any of the foregoing embodiments, in another embodiment, the control system for the real-time pointing angle of the satellite may further include an antenna theoretical pointing angle calculation module 6 and an antenna pointing angle comparison module 5.

[0151] The antenna theoretical pointing angle calculation module 6 communicates with the GNSS receiver 1, the star sensor 2, and the antenna on-orbit pointing angle calculation module 4 to obtain the first pointing angle of the current feeding cycle. The antenna pointing angle comparison module 5 communicates with the antenna on-orbit pointing angle calculation module 4 and the antenna theoretical pointing angle calculation module 6 to obtain the theoretical pointing angle and real-time pointing angle for each control cycle.

[0152] Among them, the antenna theoretical pointing angle calculation module 6 is configured to: implement the step of calculating the theoretical pointing angle of each control cycle in any of the aforementioned error calculation methods; the antenna on-orbit pointing angle calculation module 4 is also configured to: implement the step of calculating the real-time pointing angle of each control cycle in any of the aforementioned error calculation methods; the antenna pointing angle comparison module 5 is configured to: implement the step of calculating the error angle of each control cycle in any of the aforementioned error calculation methods.

[0153] In some embodiments, communication between the GNSS receiver 1 and star sensor 2 in the satellite real-time pointing angle control system and the antenna on-orbit pointing angle calculation module 4 and the antenna theoretical pointing angle calculation module 6 may include direct communication and indirect communication. For example, in Figure 9 In the embodiment shown, the GNSS receiver 1 and the star sensor 2 communicate indirectly with the on-orbit pointing angle calculation module 4 and the theoretical pointing angle calculation module 6 of the antenna through the carrier tube 3.

[0154] It is understandable that when a satellite system's GNSS fails or experiences a jump, the acquired orbital information and its timestamp will change. The real-time pointing angle calculated based on this information will deviate significantly from the theoretical pointing angle. These deviations will cause the target pointing angle determined based on the real-time pointing angle to exceed the satellite antenna's turning motion planning capabilities. According to another aspect of the present invention, a satellite pointing angle control method is provided, which can compensate for excessive errors in the determined satellite pointing angle to obtain a compensated antenna pointing target angle. This antenna pointing target angle makes the satellite antenna's turning more feasible.

[0155] To facilitate understanding, this application first briefly describes the steps of existing satellite pointing angle control methods. Existing satellite pointing angle control methods generally include: determining the real-time pointing angle of each control cycle within the current feeding cycle using a linear interpolation method based on the real-time pointing angle at the current feeding time and the real-time pointing angle at the previous feeding time; and sequentially using the real-time pointing angle of each control cycle as the antenna pointing target angle for that control cycle.

[0156] Taking any control period T1+it0 (i∈[1,n]) as an example, the real-time pointing angle of the control period T1+it0 is... in, The real-time pointing angle at the current power supply time T2. It is the real-time pointing angle at the previous power-feeding moment T1.

[0157] Figure 7 A flowchart illustrating the satellite real-time pointing angle control method disclosed in this application is shown. Figure 7 As shown, in this embodiment, the method for controlling the real-time pointing angle of the satellite includes steps S71-S74.

[0158] Step S71: Calculate the error of the current power supply cycle.

[0159] The error of the current power supply cycle includes the error angle of all control cycles within the current power supply cycle, wherein the current power supply cycle starts from the previous power supply moment and ends at the current power supply moment.

[0160] Specifically, the error of the current power supply cycle can be calculated using the error calculation method of the satellite real-time pointing angle in any of the above embodiments.

[0161] Step S72: In response to any error angle in the current power supply cycle being greater than the first preset threshold, determine that angle compensation is required in the current power supply cycle.

[0162] The first preset threshold can be set according to the planning capability of the satellite antenna's rotation movement, and the present invention does not limit this. In some embodiments, the preset threshold can be set to 0.1°.

[0163] It is understandable that if one or more error angles in the current power feeding cycle are greater than the first preset threshold, then it is determined that there is a jump in the orbital data and attitude data in the current power feeding cycle.

[0164] Angle compensation can be performed using the process data calculated in the aforementioned error calculation method, such as the theoretical pointing angle at the current power feeding moment and the real-time pointing angle at the previous power feeding moment.

[0165] Specifically, the angle compensation for the antenna pointing angle within the current feeding cycle also includes step S73: based on the real-time pointing angle at the previous feeding moment and the theoretical pointing angle at the current feeding moment, the compensation angle for each control cycle within the current feeding cycle is determined using a linear interpolation method. Taking any control cycle T1+it0 (i∈[1,n]) as an example, the compensation angle at time T1+it0 is... in, The real-time pointing angle at the previous power-on moment. This is the theoretical pointing angle at the current power supply moment.

[0166] Step S74: Sequentially use the compensation angle of each control cycle as the antenna pointing angle to the target.

[0167] It is understood that if all error angles within the current feeding cycle are less than or equal to the first preset threshold, it is determined that there is no jump in orbital and attitude data within the current feeding cycle, and the antenna pointing angle can still be determined using the existing satellite pointing angle control method. That is, the satellite pointing angle control method disclosed in this application further includes: responding to the fact that all error angles within the current feeding cycle are less than or equal to the first preset threshold, determining that angle compensation is not required for the current feeding cycle, determining the real-time pointing angle of each control cycle within the current feeding cycle using a linear interpolation method based on the real-time pointing angle at the current feeding moment and the real-time pointing angle at the previous feeding moment; and sequentially using the real-time pointing angle of each control cycle as the antenna pointing angle of the control cycle.

[0168] like Figure 9 As shown, corresponding to the satellite pointing angle control method in any of the foregoing embodiments, in another embodiment, the satellite real-time pointing angle control system may further include an angle compensation module 7.

[0169] Among them, the angle compensation module 7 communicates with the antenna pointing angle comparison module 5 and the antenna on-orbit pointing angle calculation module 4 to obtain the error angle of each control cycle in the current feeding cycle, the real-time pointing angle at the previous feeding moment, and the theoretical pointing angle at the current feeding moment, respectively. The angle compensation module 7 is configured to implement the step of determining the antenna pointing target angle in any of the aforementioned control methods.

[0170] The satellite pointing angle control method disclosed in this application may also include a verification process.

[0171] Figure 8 A flowchart illustrating the verification process in a satellite real-time pointing angle control method according to one embodiment is shown. Figure 8 As shown, in this embodiment, the method for controlling the satellite pointing angle may further include the following steps S81 to S83.

[0172] Step S81: Obtain the turntable telemetry pointing angle corresponding to the pointing angle of each antenna to the target.

[0173] The telemetry pointing angle of the turntable includes the elevation angle and the azimuth angle.

[0174] Antenna pointing is typically achieved by controlling the turntable's direction using a control unit. After the turntable is turned, the antenna pointing vector can be calculated by obtaining the turntable's sub-plane and principal plane axis angles and combining them with the antenna's mounting matrix.

[0175] For example, let the principal axis angle be θ1, the secondary axis angle be θ2, the antenna mounting matrix be C, and the antenna pointing vector be A = (x t y t , z t If the antenna pointing vector A is obtained, then the pointing vector A of the antenna can be calculated using the following formula (6):

[0176]

[0177] Where θ is the fixed angle of the antenna, which is related to the antenna design; x t y t and z t These are the three components of the antenna's pointing vector.

[0178] By pointing to vector A(x) t y t , z t The elevation angle theta1 and azimuth angle phi1 of the antenna can be calculated, where,

[0179] Step S82: Determine the control error of the satellite antenna based on the turntable telemetry pointing angle and the antenna pointing to the target angle.

[0180] The antenna pointing angle also includes the elevation angle and the azimuth angle. In a specific embodiment, the control error can be the error of the vector angle formed by the elevation angle and the azimuth angle in the antenna pointing angle relative to the vector angle formed by the elevation angle and the azimuth angle in the turntable telemetry pointing angle.

[0181] The actual pointing vector is synthesized by using the vector angle of the pointing angle measured by the turntable, and the theoretical pointing vector is synthesized by using the vector angle of the antenna pointing to the target. The vector angle error is then constructed by using the actual pointing vector and the theoretical pointing vector, thereby determining the control error of the satellite antenna.

[0182] Specifically, let the actual pointing vector be P. real The theoretical pointing vector is P. theory Let the vector angle error be Δ, the elevation and azimuth angles in the turntable telemetry pointing angle be theta1 and phi1 respectively, and the elevation and azimuth angles in the antenna pointing target angle be theta2 and phi2 respectively. Then the actual pointing vector P real Theoretical pointing vector P throry The vector angle error Δ can be expressed by the following equations (7), (8), and (9):

[0183]

[0184] Step S83: In response to the control error being greater than the second preset threshold, reconfigure the control relationship of the satellite antenna.

[0185] The second preset threshold can be set by those skilled in the art, and this invention does not limit it.

[0186] The control relationship of satellite antennas can be reconfigured through existing or future on-orbit reconfiguration methods such as software reconfiguration, hardware reconfiguration, mission reconfiguration, autonomous reconfiguration, collaborative reconfiguration, and communication reconfiguration. The correspondence between the control unit (servo controller) and the antenna turntable can be adjusted. This invention does not limit the specific reconfiguration method.

[0187] like Figure 9 As shown, corresponding to the verification process of the aforementioned control method, in another embodiment, the control system for the real-time pointing angle of the satellite may further include a servo controller 8, a turntable position telemetry module 9, and a turntable position telemetry comparison module 10.

[0188] The servo controller 8 communicates with the angle compensation module to obtain the antenna pointing angle towards the target. The servo controller 8 is configured to output control information to control the steering of the satellite antenna.

[0189] The turntable position telemetry module 9 communicates with the servo controller 8 to obtain control information. The turntable position telemetry module 9 is configured to determine the turntable telemetry pointing angle during the aforementioned verification process.

[0190] The turntable position telemetry comparison module 10 communicates with the angle compensation module 7 and the turntable position telemetry module 9 to obtain the antenna pointing angle towards the target and the corresponding turntable telemetry pointing angle for each antenna pointing angle towards the target. The turntable position telemetry comparison module 10 is configured to implement the step of determining whether the control relationship of the satellite antenna needs to be reconfigured during the aforementioned verification process.

[0191] Although the methods described above are illustrated and depicted as a series of actions for the sake of simplicity, it should be understood and appreciated that these methods are not limited by the order of the actions, as some actions may occur in a different order and / or concurrently with other actions from the illustrations and descriptions herein or not illustrated and described herein but which may be understood by those skilled in the art, according to one or more embodiments.

[0192] According to another aspect of the present invention, a control device for the real-time pointing angle of a satellite is provided. Figure 10 A schematic block diagram of a control device for the real-time pointing angle of a satellite is shown in one embodiment. Figure 10 As shown, the control device includes several memories, several processors, and computer programs stored in the memories.

[0193] The plurality of memories and processors include a first memory 101 and a first processor 102, wherein the first processor 102, when executing a computer program stored in the first memory 101, implements the steps of the method for obtaining the real-time pointing angle of a satellite as described in any of the foregoing embodiments.

[0194] Furthermore, the control device includes a second memory 103 and a second processor 104, which implements the steps of the error calculation method for the real-time pointing angle of the satellite in any of the foregoing embodiments when executing the computer program stored in the second memory 103.

[0195] Furthermore, the control device further includes a third memory 105 and a third processor 106, wherein the third processor 106 implements the steps of the satellite pointing angle control method in any of the foregoing embodiments when executing the computer program stored in the third memory 105.

[0196] It is understood that, in specific implementation, the first processor 101, the second processor 103, and the third processor 105 can be the same processor or different processors; the first memory 101, the second memory 103, and the third memory 105 can be the same memory or different memories.

[0197] According to another aspect of the present invention, a computer storage medium is provided, on which a computer program is stored. When the computer program is executed, it implements a method for obtaining a real-time satellite pointing angle, an error calculation method, and a method for controlling the satellite pointing angle. The method for obtaining a real-time satellite pointing angle is the method for obtaining a real-time satellite pointing angle in any of the foregoing embodiments, the error calculation method for a real-time satellite pointing angle is the method for calculating the error of a real-time satellite pointing angle in any of the foregoing embodiments, and the method for controlling the satellite pointing angle is the method for controlling the satellite pointing angle in any of the foregoing embodiments.

[0198] Those skilled in the art will further appreciate that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in a generalized manner in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of the invention.

[0199] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0200] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium.

[0201] The preceding description is provided to enable any person skilled in the art to practice the various aspects described herein. However, it should be understood that the scope of protection of this invention should be determined by the appended claims and should not be limited to the specific structures and components of the embodiments described above. Various changes and modifications can be made to the embodiments by those skilled in the art within the spirit and scope of this invention, and these changes and modifications also fall within the scope of protection of this invention.

Claims

1. A method for obtaining the real-time pointing angle of a satellite, characterized in that, include: Acquire several sets of orbit acquisition data and attitude acquisition data that are closest to the current power supply time, wherein the orbit acquisition data and attitude acquisition data have timestamps that identify their acquisition time; Based on the track acquisition data and attitude acquisition data, the track data and attitude data at the current power supply moment are determined respectively; as well as Based on the orbital and attitude data at the current power-feeding time, the pointing angle of the satellite toward its target ground station at the current power-feeding time is determined, and used as the real-time pointing angle of the satellite at the current power-feeding time.

2. The method for obtaining the real-time pointing angle of a satellite as described in claim 1, characterized in that, The orbital data includes at least the satellite's position coordinates. Determining the satellite's pointing angle towards its target ground station at the current feeding time based on the orbital data and attitude data includes: Based on the satellite's position coordinates at the current power-feeding time and the target ground station's position coordinates, a first pointing vector is constructed from the satellite to the target ground station; Using the orbital and attitude data at the current feeding moment, the first pointing vector is converted to the satellite's intrinsic frame to determine the intrinsic pointing vector corresponding to the first pointing vector in the satellite's intrinsic frame; and The pointing angle is calculated using the pointing vector of the system.

3. The method for obtaining the real-time pointing angle of a satellite as described in claim 2, characterized in that, Converting the first pointing vector to the satellite's intrinsic structure using the orbital and attitude data includes: The first transformation matrix from the original coordinate system to the satellite orbit system is determined using the orbit data at the current power-feeding time, wherein the original coordinate system is the reference coordinate system in which the first pointing vector is located; The first pointing vector is transformed to the satellite orbit system using the first transformation matrix to obtain the orbit system pointing vector corresponding to the first pointing vector in the satellite orbit system. The second transformation matrix from the satellite orbital system to the satellite intrinsic system is determined using the attitude data at the current feeding time; and The orbital system pointing vector is transformed to the satellite's own system using the second transformation matrix to obtain the own system pointing vector.

4. The method for obtaining the real-time pointing angle of a satellite as described in claim 1, characterized in that: The orbital data and attitude data at the current power-feeding moment determined based on the orbital acquisition data and attitude acquisition data include: Based on the track acquisition data, the track data for the current power supply time is determined using an interpolation method; and Based on the attitude acquisition data, the attitude data at the current power supply moment is determined using an extrapolation method.

5. The method for obtaining the real-time pointing angle of a satellite as described in claim 4, characterized in that, The attitude acquisition data includes at least the satellite's angular velocity and attitude quaternions; Based on the attitude acquisition data, the attitude data at the current power feeding moment is determined using an extrapolation method, including: An attitude data extrapolation matrix is ​​determined using the time difference between the timestamp in the attitude acquisition data and the current feeding time, as well as the satellite's angular velocity in the attitude acquisition data. The attitude extrapolation matrix is: Where M indicates the attitude data extrapolation matrix, W′=(w1′,w2′,w3′) represents the angular velocity of the satellite in the attitude acquisition data, w1′, w2′, and w3′ are the three angular velocity components of the satellite in its roll axis, pitch axis, and yaw axis directions, respectively, and t is the time difference between the timestamp in the attitude acquisition data and the current feeding time; and The attitude quaternion at the current feeding moment is determined using the attitude data extrapolation matrix and the attitude quaternion in the attitude acquisition data. The attitude quaternion is: Wherein, q′1, q′2, q′3 and q′4 are one of the attitude quaternions in the attitude acquisition data, and Q is the attitude quaternion at the current power feeding moment.

6. A method for calculating the error of a satellite's real-time pointing angle, characterized in that, include: The first pointing angle and the second pointing angle of the satellite in the current feeding cycle are obtained by the satellite real-time pointing angle acquisition method according to any one of claims 1 to 5, wherein the current feeding cycle starts from the previous feeding time and ends at the current feeding time, and the first pointing angle and the second pointing angle are the real-time pointing angles of the satellite at the previous feeding time and the current feeding time, respectively. The theoretical pointing angle for each control cycle within the current power supply cycle is calculated based on the first pointing angle. The real-time pointing angle for each control cycle within the current power supply cycle is calculated based on the first pointing angle and the second pointing angle; and The error angle of each control cycle is calculated based on the theoretical pointing angle and the real-time pointing angle of each control cycle, and the error angle of each control cycle in the current power supply cycle is taken as the error of the current power supply cycle.

7. A method for controlling the pointing angle of a satellite, characterized in that, include: The error of the current power supply cycle is calculated using the error calculation method described in claim 6. The error of the current power supply cycle includes the error angle of all control cycles within the current power supply cycle. The current power supply cycle starts from the previous power supply moment and ends at the current power supply moment. In response to any error angle within the current power supply cycle exceeding a first preset threshold, it is determined that angle compensation is required for the current power supply cycle; and Based on the real-time pointing angle at the previous feeding moment and the theoretical pointing angle at the current feeding moment, the compensation angle for each control cycle within the current feeding cycle is determined using a linear interpolation method; and The compensation angle of each control cycle is used as the antenna pointing angle to the target.

8. A control system for a satellite pointing angle, characterized in that, include: A GNSS receiver is used to acquire orbital data from satellites. A star sensor is used to acquire attitude data of the satellite. as well as An on-orbit pointing angle calculation module for the antenna is configured to communicate with the GNSS receiver and the star sensor to obtain several sets of orbit acquisition data and attitude acquisition data closest to the current feeding time. The orbit acquisition data and attitude acquisition data have timestamps identifying their acquisition time. The on-orbit pointing angle calculation module is configured to: determine the orbit data and attitude data at the current feeding time based on the orbit acquisition data and attitude acquisition data; and determine the pointing angle of the satellite towards its target ground station at the current feeding time based on the orbit data and attitude data at the current feeding time, as the real-time pointing angle of the satellite at the current feeding time.

9. A satellite pointing angle control device, comprising a plurality of memories, a plurality of processors, and a computer program stored in the memories, characterized in that, The plurality of memories and processors include a first memory and a first processor, wherein the first processor, when executing a computer program stored in the first memory, implements the steps of the method for obtaining the real-time pointing angle of a satellite as described in any one of claims 1 to 5; The plurality of memories and processors further include a second memory and a second processor, wherein the second processor, when executing the computer program stored in the second memory, implements the steps of the error calculation method for the real-time pointing angle of the satellite as described in claim 6; The plurality of memories and processors further include a third memory and a third processor, wherein the third processor, when executing a computer program stored in the third memory, implements the steps of the satellite pointing angle control method of claim 7.

10. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it implements a method for obtaining the real-time pointing angle of a satellite, a method for calculating the error, and a method for controlling the pointing angle of a satellite. The method for obtaining the real-time pointing angle of a satellite is the method for obtaining the real-time pointing angle of a satellite as described in any one of claims 1 to 5. The method for calculating the error of the real-time pointing angle of a satellite is the method for calculating the error of the real-time pointing angle of a satellite as described in claim 6. The method for controlling the pointing angle of a satellite is the method for controlling the pointing angle of a satellite as described in claim 7.

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