Autonomous working method of spacecraft phased array relay terminal

Abstract

The invention relates to a spacecraft phased array relay terminal autonomous working method, and provides a spacecraft phased array relay terminal autonomous working method based on a forward link locking state, which enables a phased array relay terminal to autonomously recover to work under the condition of air-ground disconnection, autonomously searches for a relay satellite, and provides an autonomous working method of the spacecraft phased array relay terminal. Therefore, the relay link can be recovered autonomously without human intervention, convenience is provided for emergency fault handling, space-ground interaction can be reduced, working efficiency can be improved, ground flight control pressure can be relieved when the system is used normally, meanwhile, the system is compatible with a previous working mode, and use is flexible.

Description

Technical Field

[0001] This invention relates to an autonomous operation method for a phased array relay terminal in a spacecraft, belonging to the field of spacecraft telemetry, tracking, and command (TT&C) communication. Background Technology

[0002] With the development of relay satellite systems, spacecraft relay terminals have been widely used in low- and medium-Earth orbit (LEO) satellites and manned spacecraft. For medium- and high-speed relay terminals, high-gain antennas are required to obtain sufficient link margin. However, high-gain antennas have narrow beams, necessitating the calculation of the terminal antenna's pointing angle based on the orbital elements of the relay satellite and the user spacecraft to control the relay terminal antenna's pointing towards the relay satellite. A large number of relay satellites are distributed across different orbital positions to achieve global coverage for LEO spacecraft. When the relay terminal antenna is pointing towards a relay satellite, it must be communicated in advance via commands or injected data, specifying which relay satellite it should be pointing at and when, as well as the satellite's orbital elements. Normal-state tracking algorithms are relatively mature and widely used in manned spacecraft and LEO satellites.

[0003] With the development of relay satellite systems, spacecraft relay terminals have been widely used in low- and medium-Earth orbit (LEO) satellites and manned spacecraft. For medium- and high-speed relay terminals, high-gain antennas are required to obtain sufficient link margin. However, high-gain antennas have narrow beams, necessitating the calculation of the terminal antenna's pointing angle based on the orbital elements of the relay satellite and the user spacecraft to control the relay terminal antenna's pointing towards the relay satellite. A large number of relay satellites are distributed across different orbital positions to achieve global coverage for LEO spacecraft. When the relay terminal antenna is pointing towards a relay satellite, it must be communicated in advance via commands or injected data, specifying which relay satellite it should be pointing at and when, as well as the satellite's orbital elements. Normal-state tracking algorithms are relatively mature and widely used in manned spacecraft and LEO satellites.

[0004] To address this issue, current spacecraft in orbit, including manned spacecraft, cargo spacecraft, space stations, and various satellites, rely on other low-speed space-to-ground links to first restore functionality. Then, with the support of these links, they power on medium-to-high-speed relay terminal equipment and track antennas to establish a relay link. The drawback of this method is that the relay terminal cannot autonomously resume operation and establish a link; it is dependent on other links and requires ground intervention. If other link equipment malfunctions and the link cannot be restored, or if ground intervention is not timely, it can lead to catastrophic consequences for the entire satellite (spacecraft, spacecraft). Summary of the Invention

[0005] The technical problem solved by this invention is that, in the existing technology, when a satellite loses contact with the ground due to power failure or other reasons, narrow-beam relay terminals such as phased array antennas cannot autonomously resume operation, cannot autonomously search for relay satellites performing tasks, and cannot establish links. This invention proposes a method for autonomous operation of phased array relay terminals in spacecraft.

[0006] The present invention solves the above-mentioned technical problem through the following technical solution:

[0007] A method for autonomous operation of a phased array relay terminal in a spacecraft includes:

[0008] Control the phased array relay terminal to power on and enter autonomous working mode;

[0009] In real time, it determines whether the phased array relay terminal has received the tracking start command. If it has not received it, it reads the preset relay satellite orbit elements. If it has received it, it determines the command type. If the current tracking start command is an autonomous tracking start command, it reads the preset relay satellite orbit elements. If the current tracking start command is not an autonomous tracking start command, it determines whether to receive the navigation data tracking start command.

[0010] Read the preset relay satellite orbit elements, and receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem;

[0011] Determine if the navigation and positioning data is normal. If it is normal, calculate the relay satellite pointing angle. If it is not normal, use the pre-injected orbit data to calculate the relay satellite pointing angle.

[0012] Based on the calculated pointing angle of the relay satellite, select the relay satellite that falls within the field of view of the relay terminal antenna for tracking. If more than one relay satellite enters the field of view of the relay terminal antenna at the same time, select the westernmost relay satellite for tracking.

[0013] Monitor whether the forward signal of the phased array relay terminal is locked. If it remains locked, continue tracking the current relay satellite and inject new orbital elements of the relay satellite when the opportunity arises. When the tracking angle exceeds the field of view of the relay antenna, or the signal is lost and exceeds a certain time, select the first relay satellite that is furthest east after the currently tracked relay satellite for tracking.

[0014] The locking situation includes: when the phased array relay terminal locks the forward signal, during the stable tracking process, the phased array relay terminal injects the latest orbital elements of the relay satellite through the phased array forward link. While the link is maintained, it is determined whether the tracking angle exceeds the antenna pointing range. If it exceeds the pointing range, the first relay satellite that is furthest east after the currently tracked relay satellite is selected for tracking.

[0015] If the forward signal of the phased array relay terminal is lost, and the loss of lock continues for more than T0 time, the first relay satellite to the east after the currently tracked relay satellite will be directly selected for tracking.

[0016] If the tracking angle does not exceed the antenna pointing range, the process jumps to re-evaluate whether the forward signal of the phased array relay terminal is locked; during the stable tracking process of the phased array relay terminal, the latest orbital elements of the relay satellite are injected at least once a day.

[0017] If the phased array relay terminal receives a tracking start command, it determines the command type. If the current tracking start command is not an autonomous tracking start command, the method for determining the navigation data tracking start command is as follows:

[0018] If the tracking start command is a navigation data tracking start command, then the phased array relay terminal is controlled to read the preset number of relay satellite orbit elements;

[0019] The phased array relay terminal is used to receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem.

[0020] Calculate the pointing angle of the relay satellite based on its orbital elements, positioning data, and attitude data.

[0021] Track the designated relay satellite based on the calculated pointing angle of the relay satellite and establish a space-to-ground link;

[0022] Specify the next relay satellite to be tracked and reread the preset relay satellite orbit elements for the specified satellite.

[0023] After establishing the space-to-ground link, during the stable tracking of the relay satellite in the phased array, the latest orbital elements of the relay satellite are injected into the uplink of the phased array forward link at least once a day.

[0024] If the tracking start command is not a navigation data tracking start command, then determine whether the received tracking start command is an orbit data tracking start command. If not, it is considered that an erroneous command has been received, and the next frame is received again to determine whether the phased array relay terminal has received the tracking start command. If so, the preset relay satellite orbital elements and spacecraft platform orbital elements are read.

[0025] The platform attitude data is received from the attitude and orbit control subsystem via a phased array relay terminal.

[0026] The pointing angle of the relay satellite is calculated based on the relay satellite's orbital elements, the platform's orbital elements, and the platform's attitude data.

[0027] The pointing angle of the relay satellite is calculated and tracked. The designated relay satellite is then tracked based on the pointing angle of the relay satellite to establish a communication link.

[0028] During the stable tracking process of the phased array relay terminal, the latest orbital elements of the relay satellite and the platform are injected into the uplink of the phased array forward link.

[0029] Specify the next relay satellite to be tracked and re-receive the platform attitude data of the selected relay satellite.

[0030] When injecting the latest orbital elements of the relay satellite and platform into the uplink of the phased array forward link, the injection shall be carried out no less than once a day, provided that the relay satellite does not perform orbit maintenance.

[0031] The phased array relay terminal uses a magnetic latching relay for power-on and power-off control, and can receive remote control commands and program control commands for power-on and power-off. After the phased array relay terminal is powered on, it enters the autonomous working mode by default in the absence of commands.

[0032] In the autonomous operating mode, the phased array relay terminal first selects a relay satellite to the west within the antenna tracking range based on the calculated pointing angle. If the forward link is locked, it continues tracking and injects the latest relay satellite orbit elements when the opportunity arises. If it cannot lock the forward signal after tracking for a certain period of time, or if the forward signal is lost for a certain period of time during tracking, it tracks the next relay satellite.

[0033] When the navigation receiver malfunctions, the relay terminal switches to orbit data tracking mode. It uses the orbit elements of the relay satellite injected from the ground and the platform attitude data to calculate the pointing angle of the relay satellite and continuously tracks it. In orbit data tracking mode, it does not switch to the relay satellite automatically and requires the ground to send a command to specify the relay satellite to be tracked.

[0034] The advantages of this invention compared to the prior art are:

[0035] (1) The present invention provides an autonomous working method for a phased array relay terminal of a spacecraft. Based on the phased array relay terminal that is widely used now, it overcomes the drawback of the current commonly used program tracking and automatic tracking that must rely on the uploading flight program to switch satellites. It proposes an autonomous working method for a phased array relay terminal of a spacecraft based on the forward link locking state. This method can enable the phased array relay terminal to resume working autonomously and search for relay satellites autonomously when the connection between the ground and space is lost. This achieves the goal of autonomously restoring the relay link without human intervention, which provides convenience for emergency fault handling. Under normal circumstances, it can reduce the interaction between the ground and space, improve work efficiency, reduce the pressure on the ground flight control, and is also compatible with the previous working mode. It is flexible in use and can also be applied to other spacecraft communication terminals with pointing functions.

[0036] (2) The phased array relay terminal of this invention can be powered on and operate autonomously without ground intervention or the transmission of satellite switching commands. The relay terminal can autonomously search for relay satellites performing missions according to the preset orbits of multiple relay satellites and establish links. When there are special needs, it can switch to navigation data tracking or orbit data tracking by command, and switch to satellite switching tracking under the guidance of ground commands. When the time of loss of connection between space and ground is too long, it can be autonomously reset and restarted to enter the autonomous working mode and establish space-ground links. After using the above working method, the phased array relay terminal can effectively solve the problem of autonomous recovery when the entire satellite (spacecraft, ship) loses power or when the space-ground link is lost due to unknown reasons, and can provide effective guarantee for the reliable operation of spacecraft in orbit;

[0037] (3) This invention has been tested in orbit on a cargo spacecraft and has achieved autonomous satellite switching and link establishment, yielding the expected test results. It can be further extended to other types of antennas with directional capabilities and can serve as a safety assurance measure for system security. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the phased array relay terminal provided by the present invention;

[0039] Figure 2 This is a schematic diagram of the autonomous workflow of the phased array relay terminal provided by the present invention. Detailed Implementation

[0040] An autonomous operation method for a spacecraft phased array relay terminal is proposed. Based on the forward link locked state, this method enables the phased array relay terminal to autonomously resume operation and search for relay satellites in the event of a loss of communication between space and ground. This allows for the autonomous restoration of the relay link without human intervention, facilitating emergency fault handling. Under normal conditions, this method reduces space-ground interaction, improves work efficiency, and alleviates the pressure on ground flight control. It is also compatible with previous operating modes, making it flexible in use.

[0041] The autonomous operation method of a spacecraft phased array relay terminal includes the following specific steps:

[0042] Specifically, it includes three lines:

[0043] The first line is the autonomous working mode line:

[0044] Control the phased array relay terminal to power on and enter autonomous working mode;

[0045] In real time, it determines whether the phased array relay terminal has received the tracking start command. If it has not received it, it reads the preset relay satellite orbit elements. If it has received it, it determines the command type. If the current tracking start command is an autonomous tracking start command, it reads the preset relay satellite orbit elements. If the current tracking start command is not an autonomous tracking start command, it determines whether to receive the navigation data tracking start command.

[0046] Read the preset relay satellite orbit elements, and receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem;

[0047] Determine if the navigation and positioning data is normal. If it is normal, calculate the relay satellite pointing angle. If it is not normal, use the pre-injected orbit data to calculate the relay satellite pointing angle.

[0048] Based on the calculated pointing angle of the relay satellite, select the relay satellite that falls within the field of view of the relay terminal antenna for tracking. If more than one relay satellite enters the field of view of the relay terminal antenna at the same time, select the westernmost relay satellite for tracking.

[0049] Monitor whether the forward signal of the phased array relay terminal is locked. If it remains locked, continue tracking the current relay satellite and inject new orbital elements of the relay satellite when the opportunity arises. When the tracking angle exceeds the field of view of the relay antenna, or the signal is lost and exceeds a certain time, select the first relay satellite that is furthest east after the currently tracked relay satellite for tracking.

[0050] Locking conditions include: when the phased array relay terminal locks on the forward signal, during the stable tracking process, the phased array relay terminal injects the latest orbital elements of the relay satellite through the phased array forward link uplink. While the link is maintained, it is determined whether the tracking angle exceeds the antenna pointing range. If it exceeds the pointing range, the first relay satellite that is furthest east after the currently tracked relay satellite is selected for tracking.

[0051] If the forward signal of the phased array relay terminal is lost, and the loss of lock continues for more than T0 time, the first relay satellite to the east after the currently tracked relay satellite will be directly selected for tracking.

[0052] If the tracking angle does not exceed the antenna pointing range, the process will switch to re-evaluating whether the forward signal of the phased array relay terminal is locked. During the stable tracking process of the phased array relay terminal, the latest orbital elements of the relay satellite will be injected at least once a day.

[0053] The second line is for navigation data tracking:

[0054] If the phased array relay terminal receives a tracking start command, it determines the command type. If the current tracking start command is not an autonomous tracking start command, the method for determining the navigation data tracking start command is as follows:

[0055] If the tracking start command is a navigation data tracking start command, then the phased array relay terminal is controlled to read the preset number of relay satellite orbit elements;

[0056] The phased array relay terminal is used to receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem.

[0057] Calculate the pointing angle of the relay satellite based on its orbital elements, positioning data, and attitude data.

[0058] Track the designated relay satellite based on the calculated pointing angle of the relay satellite and establish a space-to-ground link;

[0059] Specify the next relay satellite to be tracked and reread the preset relay satellite orbit elements for the specified satellite.

[0060] After establishing the space-to-ground link, during the stable tracking of the relay satellite in the phased array, the latest orbital elements of the relay satellite are injected into the uplink of the phased array forward link at least once a day.

[0061] The third line is the track data tracking line:

[0062] If the tracking start command is not a navigation data tracking start command, then determine whether the received tracking start command is an orbit data tracking start command. If not, it is considered that an erroneous command has been received, and the next frame is received again to determine whether the phased array relay terminal has received the tracking start command. If so, the preset relay satellite orbital elements and spacecraft platform orbital elements are read.

[0063] The platform attitude data is received from the attitude and orbit control subsystem via a phased array relay terminal.

[0064] The pointing angle of the relay satellite is calculated based on the relay satellite's orbital elements, the platform's orbital elements, and the platform's attitude data.

[0065] The pointing angle of the relay satellite is calculated and tracked. The designated relay satellite is then tracked based on the pointing angle of the relay satellite to establish a communication link.

[0066] During the stable tracking process of the phased array relay terminal, the latest orbital elements of the relay satellite and the platform are injected into the uplink of the phased array forward link.

[0067] Specify the next relay satellite to be tracked and re-receive the platform attitude data of the selected relay satellite.

[0068] Specifically, when injecting the latest orbital elements of the relay satellite and platform into the uplink of the phased array forward link, the injection shall be carried out no less than once a day if the relay satellite does not perform orbit maintenance.

[0069] Furthermore, the phased array relay terminal uses a magnetic latching relay for power-on and power-off control, and simultaneously receives remote control commands and program control commands for power-on and power-off; after the phased array relay terminal is powered on, it defaults to autonomous working mode in the absence of commands.

[0070] The following description, in conjunction with the accompanying drawings and preferred embodiments, provides further details:

[0071] In the current embodiment, the block diagram of the spacecraft phased array relay terminal is as follows: Figure 1 As shown, the phased array relay terminal establishes a space-to-ground link with the relay satellite and the relay ground terminal station in orbit, establishing a two-way communication link between the spacecraft and the spacecraft command and control center. The phased array relay terminal can integrate the antenna, demodulator, and modulator into one device, or it can be divided into two devices: a phased array antenna and a communication unit (modulation and demodulation), or three devices: a phased array receiving antenna, a phased array transmitting antenna, and a communication unit. The specific composition of the phased array relay terminal equipment can take various forms, but the operating method should adopt the following design:

[0072] (1) The phased array relay terminal equipment has the functions of forward signal reception, return signal transmission, modulation and demodulation, and tracking and pointing of relay satellites;

[0073] (2) After the phased array relay terminal is powered on, it enters autonomous tracking mode by default if no instructions are received. The autonomous tracking mode is as follows: The phased array relay terminal tracks relay satellites whose pointing angles are within the antenna tracking range (coverage area) based on the previously injected relay satellite orbit elements, the positioning data given by the satellite (ship, spacecraft) navigation receiver, and the attitude data given by the attitude and orbit control subsystem. It first attempts to track relay satellites to the west. If the forward link is locked, it maintains tracking and injects the latest relay satellite orbit elements when the opportunity arises. If the tracking continues for more than a certain period of time T a If the forward signal cannot be locked within 30 seconds (e.g.), or if the forward signal is lost for more than a certain time T during the tracking process. a Then, it tracks the next relay satellite. This strategy ensures that the relay terminal can autonomously find the relay satellite performing the mission and establish a link within a controllable time frame, providing uplink and downlink paths;

[0074] (3) If the spacecraft is without an uplink for an extended period of time, and the platform's central controller timing exceeds a certain time T u(It is usually set to 36 hours because under normal circumstances, uplink data needs to be injected from the ground every 24 hours. If uplink injection is not received after 36 hours, it proves that the uplink has been abnormally interrupted.) After that, if the total count of remote injection does not change, the phased array relay terminal will be automatically powered off again, allowing the phased array relay terminal to enter the autonomous tracking mode and autonomously restore the link.

[0075] (4) The phased array relay terminal works in autonomous tracking mode by default. When there is a special need, it can be switched to other tracking modes by sending corresponding remote control or program control commands. Other tracking modes include navigation data tracking mode and track data tracking mode. In other tracking modes, it can also be switched back to autonomous tracking mode by commands.

[0076] (5) Navigation data tracking mode is a supplementary mode to autonomous tracking mode. Based on the programmable command, it specifies the relay satellite to be tracked, calculates the relay satellite's pointing angle using the relay satellite's orbital elements injected from the ground and the positioning and attitude data provided by the platform, and continuously tracks the satellite without automatically switching relay satellites. This mode can be used when the ground can normally send satellite switching commands;

[0077] (6) The orbit data tracking mode is the tracking mode under navigation receiver failure conditions. Based on the program control command, the relay satellite to be tracked is specified. The pointing angle of the relay satellite is calculated using the orbital elements of the relay satellite injected from the ground, the orbital elements of the satellite (or spacecraft), and the attitude data provided by the platform. Tracking is continuous without automatic switching of the relay satellite. This mode is used to cope with platform navigation receiver failure conditions.

[0078] (7) Phased array relay terminal equipment should use magnetic latching relays for power on and off, which can ensure that the equipment can be automatically powered on when the entire satellite (or spacecraft) loses power and is then restored, without ground intervention.

[0079] Example 1:

[0080] like Figure 2 As shown, the implementation steps of the autonomous operation method for phased array relay terminals are as follows:

[0081] Step 1: The phased array relay terminal is powered on and enters autonomous working mode by default;

[0082] Step 2: Determine if a tracking start command has been received. If no command has been received, continue to Step 3. If a command has been received, jump to Step 12.

[0083] Step 3: Read the preset relay satellite orbit elements;

[0084] Step 4: Receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem;

[0085] Step 5: Determine if the autonomous positioning data is normal. If normal, continue to Step 6; if not, proceed to Step 5.1.

[0086] Step 5.1: Calculate the pointing angle using the pre-injected orbital data;

[0087] Step 6: Calculate the relay satellite pointing angle based on the relay satellite's orbital elements, autonomous positioning data (or pre-injected orbital data), and attitude data;

[0088] Step 7: Based on the calculated pointing angle of the relay satellite, select the relay satellite that falls within the field of view of the relay terminal antenna for tracking. If multiple relay satellites enter the field of view of the relay terminal antenna at the same time, select the relay satellite on the west side for tracking.

[0089] Step 8: Monitor whether the forward signal of the phased array relay terminal is locked. If it is locked, continue to step 9; if it is continuously lost for more than T0 (which can be 30s), jump to step 11.

[0090] Step 9: During the stable tracking process of the phased array relay terminal, inject the latest orbital elements of the relay satellite into the uplink of the phased array forward link. This step does not need to be performed every orbit; if the relay satellite is not performing orbit maintenance, it is sufficient to inject the elements at least once a day.

[0091] Step 10: While maintaining the link, the phased array relay terminal determines whether the tracking angle exceeds the antenna pointing range. If not, proceed to step 8; if it exceeds the pointing range, continue to step 11.

[0092] Step 11: Select the first relay satellite (east of the current relay satellite) to track, and then proceed to step 7.

[0093] Step 12: Determine whether the received tracking start command is an autonomous tracking start command. If yes, proceed to step 3; otherwise, continue to step 13.

[0094] Step 13: Determine whether the received tracking start command is a navigation data tracking start command. If yes, continue to step 14; otherwise, continue to step 20.

[0095] Step 14: The phased array relay terminal reads the preset number of relay satellite orbit elements;

[0096] Step 15: The phased array relay terminal receives navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem;

[0097] Step 16: The phased array relay terminal calculates the pointing angle of the relay satellite based on the relay satellite's orbital elements, positioning data, and attitude data;

[0098] Step 17: Track the designated relay satellite based on the calculated relay satellite pointing angle and establish a space-to-ground link;

[0099] Step 18: During the stable tracking process of the phased array relay terminal, inject the latest orbital elements of the relay satellite into the uplink of the phased array forward link. This step does not need to be performed every orbit; if the relay satellite is not performing orbit maintenance, it is sufficient to inject the elements at least once a day.

[0100] Step 19: Specify the next relay satellite to be tracked and jump to step 14;

[0101] Step 20: Determine whether the received tracking start command is a track data tracking start command. If yes, continue to step 21. If not, consider it an erroneous command and jump to step 2.

[0102] Step 21: Read the preset relay satellite orbit elements and spacecraft platform orbit elements;

[0103] Step 22: The phased array relay terminal receives attitude data sent by the attitude and orbit control subsystem;

[0104] Step 23: The phased array relay terminal calculates the pointing angle of the relay satellite based on the relay satellite orbit elements, platform orbit elements, and platform attitude data;

[0105] Step 24: Track the calculated pointing angle of the relay satellite, track the designated relay satellite, and establish a link;

[0106] Step 25: During the stable tracking process of the phased array relay terminal, inject the latest orbital elements of the relay satellite and the platform through the phased array forward link uplink. This step does not need to be performed every orbit; if the relay satellite does not perform orbit maintenance, it is sufficient to inject the elements at least once a day.

[0107] Step 26: Specify the next relay satellite to be tracked and proceed to step 22.

[0108] Depending on the program or ground arrangements, the phased array relay terminal can receive power-off remote control commands or program control commands at any step in any operating mode. After powering off, it exits all operating procedures and, upon powering on again, resumes the process from step 1 of the autonomous operating mode. The three operating modes can be switched arbitrarily via commands.

[0109] In this embodiment, the phased array relay terminal equipment has the functions of forward signal reception, backward signal transmission, modulation and demodulation, and tracking and pointing of relay satellites. The phased array relay terminal equipment uses a magnetic latching relay for power-on and power-off control, and can simultaneously receive remote control commands and programmable commands for power-on and power-off. After the equipment is powered on, it enters autonomous working mode by default if no commands are received.

[0110] The autonomous operating mode is as follows: The phased array relay terminal tracks relay satellites within the antenna tracking range (coverage area) based on the previously injected relay satellite orbit elements, the positioning data provided by the spacecraft navigation receiver, and the attitude data provided by the attitude and orbit control subsystem. It first attempts to track relay satellites to the west. If the forward link is locked, it maintains tracking and injects the latest relay satellite orbit elements as appropriate. If it cannot lock the forward signal after tracking for a certain period of time, or if the forward signal is lost for a certain period of time during tracking, it tracks the next relay satellite (the relay satellite to the east of the current relay satellite).

[0111] If the total count of remote control injection remains unchanged after the spacecraft's central controller has been timing for a certain period of time, the phased array relay terminal will be automatically powered off again, allowing it to enter autonomous working mode and autonomously restore the link.

[0112] When powered on, the phased array relay terminal can receive corresponding remote or programmable commands and enter other tracking modes, including navigation data tracking mode and track data tracking mode. In other tracking modes, it can also enter autonomous working mode by receiving commands.

[0113] As a supplementary mode to the autonomous working mode, the navigation data tracking mode specifically uses the orbital elements of the relay satellite injected from the ground and the positioning and attitude data provided by the platform to calculate the pointing angle of the relay satellite and continuously track it. During the process, the relay satellite is not switched autonomously, and the ground needs to send a command to specify the relay satellite to be tracked.

[0114] The orbit data tracking mode is used as the tracking mode under the fault condition of the navigation receiver. Specifically, when the relay terminal cannot receive the correct autonomous positioning data, it will switch to the orbit data tracking mode autonomously. It will calculate the pointing angle of the relay satellite using the orbital elements of the relay satellite injected by the ground, the orbital elements of the satellite (spacecraft, ship) and the attitude data provided by the platform, and continue to track it. During the process, it will not switch the relay satellite autonomously. It will need to send a command from the ground to specify the relay satellite to be tracked.

[0115] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0116] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for autonomous operation of a phased array relay terminal in a spacecraft, characterized in that... include: Control the phased array relay terminal to power on and enter autonomous working mode; In real time, it determines whether the phased array relay terminal has received the tracking start command. If it has not received it, it reads the preset relay satellite orbit elements. If it has received it, it determines the command type. If the current tracking start command is an autonomous tracking start command, it reads the preset relay satellite orbit elements. If the current tracking start command is not an autonomous tracking start command, it determines whether to receive the navigation data tracking start command. Read the preset relay satellite orbit elements, and receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem; Determine if the navigation and positioning data is normal. If it is normal, calculate the relay satellite pointing angle. If it is not normal, use the pre-injected orbit data to calculate the relay satellite pointing angle. Based on the calculated pointing angle of the relay satellite, select the relay satellite that falls within the field of view of the relay terminal antenna for tracking. If more than one relay satellite enters the field of view of the relay terminal antenna at the same time, select the westernmost relay satellite for tracking. Monitor whether the forward signal of the phased array relay terminal is locked. If it remains locked, continue tracking the current relay satellite and inject new orbital elements of the relay satellite when the opportunity arises. When the tracking angle exceeds the field of view of the relay antenna, or the signal is lost and exceeds a certain time, select the first relay satellite that is furthest east after the currently tracked relay satellite for tracking.

2. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 1, characterized in that: The locking situation includes: when the phased array relay terminal locks the forward signal, during the stable tracking process, the phased array relay terminal injects the latest orbital elements of the relay satellite through the phased array forward link. While the link is maintained, it is determined whether the tracking angle exceeds the antenna pointing range. If it exceeds the pointing range, the first relay satellite that is furthest east after the currently tracked relay satellite is selected for tracking. If the forward signal of the phased array relay terminal is lost, and the loss of lock continues for more than T0 time, the first relay satellite to the east after the currently tracked relay satellite will be directly selected for tracking.

3. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 2, characterized in that: If the tracking angle does not exceed the antenna pointing range, the process jumps to re-evaluate whether the forward signal of the phased array relay terminal is locked; during the stable tracking process of the phased array relay terminal, the latest orbital elements of the relay satellite are injected at least once a day.

4. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 2, characterized in that: If the phased array relay terminal receives a tracking start command, it determines the command type. If the current tracking start command is not an autonomous tracking start command, the method for determining the navigation data tracking start command is as follows: If the tracking start command is a navigation data tracking start command, then the phased array relay terminal is controlled to read the preset number of relay satellite orbit elements; The phased array relay terminal is used to receive navigation and positioning data sent by the satellite navigation receiver and attitude data sent by the attitude and orbit control subsystem. Calculate the pointing angle of the relay satellite based on its orbital elements, positioning data, and attitude data. Track the designated relay satellite based on the calculated pointing angle of the relay satellite and establish a space-to-ground link; Specify the next relay satellite to be tracked and reread the preset relay satellite orbit elements for the specified satellite.

5. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 4, characterized in that: After establishing the space-to-ground link, during the stable tracking of the relay satellite in the phased array, the latest orbital elements of the relay satellite are injected into the uplink of the phased array forward link at least once a day.

6. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 4, characterized in that: If the tracking start command is not a navigation data tracking start command, then determine whether the received tracking start command is an orbit data tracking start command. If not, it is considered that an erroneous command has been received, and the next frame is received again to determine whether the phased array relay terminal has received the tracking start command. If so, the preset relay satellite orbital elements and spacecraft platform orbital elements are read. The platform attitude data is received from the attitude and orbit control subsystem via a phased array relay terminal. The pointing angle of the relay satellite is calculated based on the relay satellite's orbital elements, the platform's orbital elements, and the platform's attitude data. The pointing angle of the relay satellite is calculated and tracked. The designated relay satellite is then tracked based on the pointing angle of the relay satellite to establish a communication link. During the stable tracking process of the phased array relay terminal, the latest orbital elements of the relay satellite and the platform are injected into the uplink of the phased array forward link. Specify the next relay satellite to be tracked and re-receive the platform attitude data of the selected relay satellite.

7. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 6, characterized in that: When injecting the latest orbital elements of the relay satellite and platform into the uplink of the phased array forward link, the injection shall be carried out no less than once a day, provided that the relay satellite does not perform orbit maintenance.

8. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 6, characterized in that: The phased array relay terminal uses a magnetic latching relay for power-on and power-off control, and can receive remote control commands and program control commands for power-on and power-off. After the phased array relay terminal is powered on, it enters the autonomous working mode by default in the absence of commands.

9. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 8, characterized in that: In the autonomous working mode, the phased array relay terminal first selects the relay satellite to the west within the antenna tracking range based on the calculated pointing angle. If the forward link is locked, it maintains tracking and injects the latest relay satellite orbit elements when the opportunity arises. If the forward signal cannot be locked after continuous tracking for a certain period of time, or if the forward signal is lost for a certain period of time during the tracking process, then track the next relay satellite.

10. The autonomous operation method of a phased array relay terminal for a spacecraft according to claim 9, characterized in that: When the navigation receiver malfunctions, the relay terminal switches to orbit data tracking mode, calculates the relay satellite pointing angle using the relay satellite orbit elements and platform attitude data injected from the ground, and continuously tracks it; In orbital data tracking mode, the system does not automatically switch to a relay satellite; ground control requires a command to specify the relay satellite to be tracked.

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