Method and system for identifying and processing abnormal switching code groups of satellite mission systems

Abstract

The present invention provides a method and system for identifying and processing abnormal switching code groups in a satellite mission system, including: S1: The TT&C transponder of the satellite is in a normal working state and receives a switching backup code group command; S2: The software checks whether there is a reception failure in the uplink telecommand and further investigates the cause. If the relay channel is abnormal, the switching backup code group command is normally executed; otherwise, the command is regarded as an abnormal behavior and blocked; S3: The software checks whether there is a failure in the downlink telemetry transmission and further investigates the cause. If the relay channel is abnormal, the switching backup code group command is normally executed; otherwise, the command is regarded as an abnormal behavior and blocked. Through multi-level diagnosis and processing of transponder failures, the present invention can quickly locate problems and take effective measures, avoid system misjudgment and further failures, and improve the reliability of the satellite TT&C system.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite security protection, and specifically, to a method and system for identifying and processing abnormal switching code groups in a satellite service system. Background Art

[0002] With the rapid development of modern space technology, satellites are increasingly widely used in fields such as communication, navigation, meteorology, and remote sensing. As a complex spacecraft, the reliability and stability of a satellite during on-orbit operation are directly related to the completion of its mission. However, during actual operation, the satellite's TT&C system may be affected by various internal and external factors, resulting in failures or anomalies in the TT&C transponder. Especially after receiving the command to switch to the backup code group, it may cause the transponder to enter the working state of the backup code group, leading to problems such as loss of lock, response delay, or communication interruption. This not only affects the normal operation of the satellite but may also cause deviations in the ground station's fault judgment and handling of the satellite.

[0003] Currently, most of the existing methods for handling anomalies in TT&C transponders are limited to simple redundant switching or direct restart operations, lacking targeted and systematic fault diagnosis and recovery strategies. This approach may not only fail to solve practical problems but may also waste redundant resources due to misjudgment, and even cause more serious system failures.

[0004] Therefore, there is a need for a method that can accurately identify the abnormal behavior of the TT&C transponder after receiving the command to switch to the backup code group through a multi-level diagnostic mechanism and processing strategy, and formulate reasonable countermeasures in combination with multi-dimensional information such as the up and down link signal status, antenna pointing, and link quality.

[0005] Patent application document CN113114186A discloses a method for autonomous reset control of a TT&C transponder. The satellite autonomously identifies the TT&C arc segment and autonomously calculates the TT&C reset time window that does not overlap with the normal TT&C time, and performs the reset of the TT&C transponder within the TT&C reset time window to avoid interruption of the satellite's normal TT&C due to autonomous reset. However, this patent cannot completely solve the existing technical problems and also cannot meet the requirements of the present invention. Summary of the Invention

[0006] Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a method and system for identifying and processing abnormal switching code groups in a satellite service system.

[0007] According to the method for identifying and processing abnormal switching code groups in a satellite service system provided by the present invention, it includes:

[0008] Step 1: The TT&C transponder of the satellite is in a normal working state and receives a command to switch to the backup code group;

[0009] Step 2: Check whether there is a receiving failure in the uplink remote control through software, and further troubleshoot the cause. If the relay channel is abnormal, execute the command to switch the backup code group normally; otherwise, shield the command as an abnormal behavior.

[0010] Step 3: Check whether there is a failure in the downlink telemetry transmission through software, and further troubleshoot the cause. If the relay channel is abnormal, execute the command to switch the backup code group normally; otherwise, shield the command as an abnormal behavior.

[0011] Preferably, when the TT&C transponder of the first satellite is in a normal working state and receives the command to switch the backup code group, after responding, the transponder works in the backup code group state, resulting in no response from the transponder. First, check whether there is a receiving failure in the uplink remote control through software, and check the voltage value of the telemetry information in the uplink locked state. If it is between -0.15V and 0.5V, it is confirmed that the signal is in an unlocked state; at the same time, it is also confirmed whether the AGC telemetry signal exceeds the normal range. If it is not within the range of [-130, -42] dBm, further check whether the signal-to-noise ratio telemetry is lower than the normal range. If telemetry A is lower than 90 and telemetry B is lower than 25, it is confirmed that there is a failure in the uplink telemetry reception.

[0012] Preferably, increase the uplink power on the ground and try to transmit the remote control data packet from the geostationary satellite to the first satellite again. If it is received normally, it is judged that the antenna gain has decreased, and the software shields the command to switch the backup code group as an abnormal behavior; if there is still an abnormal reception situation when increasing the uplink power to the first satellite, send a baseband reset instruction to the unlocked transponder through software. If the unlocked transponder does not execute the baseband reset command, decompose the received instruction. If there is missing data in the received instruction, or the received instruction is complete but the unlocked transponder delays in responding to the baseband reset instruction, it is judged that the transponder receiving link is abnormal;

[0013] If the unlocked transponder normally executes the baseband reset instruction, further send a power-on / off instruction to the unlocked transponder to restart the unlocked transponder. If it returns to normal after restart, it is a situation where the FPGA loading of the transponder is abnormal. The software shields the command to switch the backup code group as an abnormal behavior; if there is still an error after restart, use the relay satellite channel to send a remote control instruction to test the unlocked transponder. If there is no response for a long time after sending the remote control instruction and it is found that the remote control instruction has not been received when checking the link of the unlocked transponder, the situation is that the relay satellite channel is abnormal, and the software regards the command to switch the backup code group as a normal behavior and executes the instruction normally.

[0014] Preferably, software is used to check whether there is a fault in the downlink telemetry transmission. If there is an abnormality in the ground telemetry lock or the ground received signal is weak or there is no signal, it is confirmed whether the antenna field of view meets the requirements of telemetry and telecontrol under the current satellite attitude; the actual pointing direction of the antenna is confirmed by obtaining the current three-axis attitude angles from the attitude and orbit control subsystem, and the installation offset angle of the antenna relative to the satellite body coordinate system is used to calculate the specific position of the antenna pointing direction in the geocentric inertial coordinate system. According to the beam width, gain pattern and field of view model of the antenna, its current pointing range is determined;

[0015] Construct a combined quaternion from the three-axis attitude angles of the satellite , representing the rotation from the satellite body coordinate system to the geocentric inertial coordinate system, where the pitch angle around the y-axis is , the yaw angle around the z-axis is , and the roll angle around the x-axis is , then there is:

[0016] Quaternion for rotation about the x-axis

[0017] Quaternion for rotation about the y-axis

[0018] Quaternion for rotation about the z-axis

[0019]

[0020] The specific position of the antenna pointing direction in the geocentric inertial coordinate system: ;

[0021] where represents the conjugate of the quaternion; represents the vector of the antenna direction in the satellite body coordinate system.

[0022] Preferably, according to the two-line element set (TLE) data of the satellite and the geographical coordinates of the ground station, the distance, azimuth and elevation angle between the satellite and the ground station are calculated using the orbital dynamics model; the relative position of the ground station is projected into the antenna field of view model. If the ground station is located in the edge area or sidelobe range, all gains and losses during the process from the transmitter to the receiver are comprehensively calculated. If the requirements are not met, it is judged that the antenna pointing is inaccurate, and the software will regard the switching of the backup code group command as an abnormal behavior and block the command; if the ground station is located in the main lobe center area, the backup transponder is used to receive the telemetry information. If the backup transponder successfully receives the telemetry information, the software will regard the switching of the backup code group command as an abnormal behavior and block the command; if the backup transponder cannot receive the telemetry information, the relay channel is used to send the remote control command. If the backup transponder also has no response, the software will regard the switching of the backup code group command as a normal behavior and execute the command normally;

[0023] Calculate the distance, azimuth, and elevation angle between the satellite and the ground station using the orbital dynamics model. Specifically: Extract the orbital elements, obtain the satellite's orbital inclination, argument of perigee, right ascension of the ascending node, eccentricity, mean motion, and epoch time, and calculate the time difference between the current time and the TLE epoch time. :

[0024]

[0025] Among them, represents the current time, represents the TLE epoch time, a(t) is the magnitude of the acceleration at the current time; k is an adjustment factor, shortening the step size at the perigee and increasing the step size at the apogee;

[0026] Calculate the eccentric anomaly from the mean anomaly using Kepler's equation:

[0027]

[0028] Among them, M is the mean anomaly, E is the eccentric anomaly, and e is the orbital eccentricity;

[0029] Solve for E using the iterative method: ;

[0030] Iterate continuously until the residual ( - ) is less than ; and are the results of two consecutive iterations;

[0031] In the orbital plane, calculate the position ( , y) and velocity :

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] Among them, a is the semi-major axis of the orbit, v is the true anomaly, is the gravitational parameter of the Earth;

[0038] Then convert the orbital plane coordinate system to the geocentric inertial coordinate system and comprehensively calculate all the gains and losses during the process of the signal from the transmitter to the receiver.

[0039]

[0040] Among them, represents the received power, represents the transmitted power, represents the transmitting antenna gain, represents the receiving antenna gain, represents the free space path loss, represents the atmospheric propagation loss, represents the system loss and polarization loss; compare the received power with the communication threshold, if it is less than the communication threshold, the requirement is not met.

[0041] According to the star service system abnormal handover code group recognition and processing system provided by the present invention, it includes:

[0042] Module M1: The TT&C transponder of the satellite is in a normal working state and receives the handover backup code group command;

[0043] Module M2: Check through software whether there is a receiving failure in the uplink telecommand, and further investigate the cause. If the relay channel is abnormal, execute the handover backup code group command normally, otherwise shield the command as an abnormal behavior;

[0044] Module M3: Check through software whether there is a failure in the downlink telemetry transmission, and further investigate the cause. If the relay channel is abnormal, execute the handover backup code group command normally, otherwise shield the command as an abnormal behavior.

[0045] Preferably, the TT&C transponder of the first satellite is in a normal working state and receives the handover backup code group command. After responding, the transponder works in the backup code group state, resulting in no response from the transponder. First, check through software whether there is a receiving failure in the uplink telecommand. The voltage value of the telemetry information in the uplink locked state is checked. If it is between -0.15V and 0.5V, it is confirmed that the signal is in the unlocked state; at the same time, it is also confirmed whether the AGC telemetry signal exceeds the normal range. If it is not in the range of [-130, -42] dBm, further check whether the signal-to-noise ratio telemetry is lower than the normal range. If telemetry A is lower than 90 and telemetry B is lower than 25, it is confirmed that there is a failure in the uplink telemetry reception.

[0046] Preferably, increase the uplink power to the ground and try to transmit the telecommand data packet from the geostationary satellite to the first satellite again. If it is received normally, it is determined that the antenna gain has decreased, and the software regards the command to switch the backup code group as an abnormal behavior and shields this command; if the reception is still abnormal after increasing the uplink power to the first satellite, send a baseband reset instruction to the loss-of-lock transponder through the software. If the loss-of-lock transponder does not execute the baseband reset command, decompose the received instruction. If there is missing instruction data, or the received instruction is complete but the loss-of-lock transponder delays in responding to the baseband reset instruction, it is determined that the transponder reception link is abnormal.

[0047] If the loss-of-lock transponder normally executes the baseband reset instruction, further send a power-on / off instruction to the loss-of-lock transponder to restart it. If it returns to normal after restart, it indicates a situation where the FPGA loading of the transponder is abnormal. The software regards the command to switch the backup code group as an abnormal behavior and shields this command; if the error still occurs after restart, send a telecommand through the relay satellite channel to test the loss-of-lock transponder. If there is no response for a long time after sending the telecommand and it is found that the telecommand is not received when checking the link of the loss-of-lock transponder, it indicates that the relay satellite channel is abnormal. The software regards the command to switch the backup code group as a normal behavior and executes this command normally.

[0048] Preferably, check whether there is a fault in the downlink telemetry transmission through the software. If the ground telemetry lock is abnormal, or the ground received signal is weak or there is no signal, confirm whether the antenna field of view meets the requirements of telemetry and telecommand under the current satellite attitude; obtain the current three-axis attitude angles from the attitude and orbit control subsystem to confirm the actual pointing direction of the antenna, use the installation offset angle of the antenna relative to the satellite body coordinate system, calculate the specific position of the antenna pointing direction in the geocentric inertial coordinate system, and determine its current pointing range according to the beam width, gain pattern and field of view model of the antenna.

[0049] Construct a combined quaternion from the three-axis attitude angles of the satellite , representing the rotation from the satellite body coordinate system to the geocentric inertial coordinate system. Among them, the pitch angle around the y-axis is , the yaw angle around the z-axis is , and the roll angle around the x-axis is , then there is:

[0050] Quaternion for rotation around the x-axis

[0051] Quaternion for rotation around the y-axis

[0052] Quaternion for rotation around the z-axis

[0053]

[0054] The specific position of the antenna pointing direction in the geocentric inertial coordinate system: ;

[0055] where represents the conjugate of the quaternion; represents the vector of the antenna direction in the satellite body coordinate system.

[0056] Preferably, according to the two-line element set (TLE) data of the satellite and the geographical coordinates of the ground station, use the orbital dynamics model to calculate the distance, azimuth, and elevation angle between the satellite and the ground station; project the relative position of the ground station into the antenna field of view model. If the ground station is located in the edge area or sidelobe range, comprehensively calculate all the gains and losses during the process of the signal from the transmitter to the receiver. If the requirements are not met, it is determined that the antenna pointing is inaccurate, and the software will regard the command to switch the backup code group as an abnormal behavior and block the command; if the ground station is located in the main lobe center area, use the backup transponder to receive the telemetry information. If the backup transponder successfully receives the telemetry information, the software will regard the command to switch the backup code group as an abnormal behavior and block the command; if the backup transponder cannot receive the telemetry information, use the relay channel to send the remote control command. If the backup transponder also has no response, the software will regard the command to switch the backup code group as a normal behavior and execute the command normally;

[0057] Use the orbital dynamics model to calculate the distance, azimuth, and elevation angle between the satellite and the ground station. Specifically: Extract the orbital elements, obtain the satellite's orbital inclination, argument of perigee, right ascension of the ascending node, eccentricity, mean motion, and epoch time, and calculate the time difference between the current time and the TLE epoch time :

[0058]

[0059] where represents the current time, represents the TLE epoch time, a(t) is the magnitude of the acceleration at the current time; k is an adjustment factor, shortening the step length at the perigee and increasing the step length at the apogee;

[0060] Use Kepler's equation to calculate the eccentric anomaly from the mean anomaly:

[0061]

[0062] where M is the mean anomaly, E is the eccentric anomaly, and e is the orbital eccentricity;

[0063] Use the iterative method to solve for E: ;

[0064] Iterate continuously until the residual ( - is less than ; and are the results of two consecutive iterations;

[0065] In the orbital plane, calculate the position ( , y) and velocity of the satellite:

[0066]

[0067]

[0068]

[0069]

[0070]

[0071] where a is the semi-major axis of the orbit, v is the true anomaly, is the gravitational parameter of the Earth;

[0072] Then convert the orbital plane coordinate system to the geocentric inertial coordinate system, and comprehensively calculate all the gains and losses during the process of the signal from the transmitter to the receiver;

[0073]

[0074] where represents the received power, represents the transmitted power, represents the transmitting antenna gain, represents the receiving antenna gain, represents the free space path loss, represents the atmospheric propagation loss, represents the system loss and polarization loss; Compare the received power with the communication threshold. If it is less than the communication threshold, the requirement is not met.

[0075] Compared with the prior art, the present invention has the following beneficial effects:

[0076] (1) Through multi-level diagnosis and processing of the transponder failure, the present invention can quickly locate the problem and take effective measures, avoid system misjudgment and further failures, and improve the reliability of the satellite TT&C system;

[0077] (2) Through software, the present invention can dynamically judge the abnormality of the switching backup code group command and perform shielding processing on the abnormal command, effectively avoiding the system operation risk caused by incorrect commands. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non - limiting embodiments read in conjunction with the accompanying drawings:

[0079] Figure 1 It is a flowchart of a method for identifying and processing abnormal switching code groups in a satellite service system;

[0080] Figure 2 It is a flowchart for processing a switching backup code group command caused by a reception failure in uplink telecommand;

[0081] Figure 3 It is a flowchart of a switching backup code group command caused by a transmission failure in downlink telemetry. Detailed implementation manners

[0082] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention.

[0083] Embodiment

[0084] The present invention provides a method for identifying and processing abnormal switching code groups in a satellite service system, including:

[0085] 1) When the TT&C transponder of the first satellite is in a normal working state and receives a switching backup code group command, after responding, it will cause the transponder to work in the backup code group state, resulting in the transponder having no response. The software will first check whether there is a reception failure in the uplink telecommand. The voltage value of the telemetry information in the uplink locked state will be checked. If it is between - 0.15V and 0.5V, it is confirmed that the signal is in an unlocked state. At the same time, it will also be confirmed whether the AGC telemetry signal exceeds the normal range. If it is not in the range of [-130, -42] dBm, further check whether the signal - to - noise ratio telemetry is lower than the normal range. If telemetry A is lower than 90 and telemetry B is lower than 25, it is confirmed that there is a reception failure in the uplink telemetry.

[0086] 2) The ground increases the uplink power and tries again to transmit the telecommand data packet from the geostationary satellite to the first satellite. If it can be received normally, it is judged that the antenna gain has decreased. The software regards the switching backup code group command as an abnormal behavior and masks the command. If the first satellite still has a reception anomaly after increasing the uplink power, a baseband reset instruction is sent to the unlocked transponder through the software. If the unlocked transponder does not execute the baseband reset command, the received instruction is decomposed. If there is missing data in the received instruction, or the received instruction is complete, but the unlocked transponder delays the response to the baseband reset instruction, it is judged that the situation is an abnormal reception link of the transponder.

[0087] 3) If the out-of-lock transponder normally executes the baseband reset instruction, further send the power-on and power-off instruction to the out-of-lock transponder to restart it. If it returns to normal after restart, it indicates a situation where the FPGA of the transponder fails to load properly. The software will regard the switching of the backup code group command as an abnormal behavior and block this command. If an error still occurs after restart, send a telecommand through the relay satellite channel to test the out-of-lock transponder. If there is no response for a long time after sending the telecommand and it is found that the out-of-lock transponder does not receive the telecommand by checking its link, it indicates that the relay satellite channel is abnormal. The software will regard the switching of the backup code group command as a normal behavior and execute this command normally.

[0088] 4) Secondly, the software will check whether there is a fault in the downlink telemetry transmission. If the ground telemetry is locked abnormally, or the ground received signal is weak or there is no signal, it is necessary to confirm whether the antenna field of view meets the requirements of telemetry and telecommand under the current satellite attitude. Obtain the current three-axis attitude angles (pitch, yaw, roll) from the attitude and orbit control subsystem to confirm the actual pointing direction of the antenna. Use the installation offset angle of the antenna relative to the satellite body coordinate system to calculate the specific position of the antenna pointing direction in the geocentric inertial coordinate system. Determine its current pointing range (the coverage area of the main lobe and the side lobe) according to the beam width, gain pattern and field of view model of the antenna.

[0089] Construct a combined quaternion using the three-axis attitude angles of the satellite (pitch angle about the y-axis , yaw angle about the z-axis , roll angle about the x-axis ) to represent the actual pointing direction of the antenna.

[0090] It represents the rotation from the satellite body coordinate system to the geocentric inertial coordinate system.

[0091] Quaternion for x-axis rotation

[0092] Quaternion for y-axis rotation

[0093] Quaternion for z-axis rotation

[0094]

[0095] The specific position of the antenna pointing direction in the geocentric inertial coordinate system: ;

[0096] where represents the conjugate of the quaternion.

[0097] Calculation method:

[0098] Assume ,

[0099] = 。

[0100] 5) Calculate the distance, azimuth, and elevation angle between the satellite and the ground station using the orbital dynamics model based on the two-line element (TLE) data of the satellite and the geographical coordinates of the ground station. Project the relative position of the ground station into the antenna field-of-view model. If the ground station is located in the edge area or sidelobe range, comprehensively calculate all the gains and losses during the signal transmission from the transmitter to the receiver. If the requirements are not met, it is determined that the antenna pointing is inaccurate, and the software will regard the switching of the backup code group command as an abnormal behavior and block the instruction. If the ground station is located in the main lobe center area, use the backup transponder to receive the telemetry information. If the backup transponder successfully receives the telemetry information, the software will regard the switching of the backup code group command as an abnormal behavior and block the instruction. If the backup transponder fails to receive the telemetry information, send the remote control instruction through the relay channel. If the backup transponder also has no response, the software will regard the switching of the backup code group command as a normal behavior and execute the instruction normally.

[0101] Calculate the distance, azimuth, and elevation angle between the satellite and the ground station using the orbital dynamics model:

[0102] Extract the orbital elements to obtain the satellite's orbital inclination, argument of perigee, right ascension of the ascending node, eccentricity, mean motion, and epoch time. Calculate the time difference between the current time and the TLE epoch time :

[0103]

[0104] where, represents the current time, represents the TLE epoch time, a(t) is the magnitude of the acceleration at the current time, k is the adjustment factor, automatically shorten the step size at the perigee and increase the step size at the apogee.

[0105] Calculate the eccentric anomaly from the mean anomaly using Kepler's equation: M = E - e sin(E); where, M is the mean anomaly, E is the eccentric anomaly, and e is the orbital eccentricity.

[0106] Solve for E using the iterative method: , and keep iterating until the residual ( - ) is less than .

[0107] Calculate the position and velocity of the satellite in the orbital plane:

[0108] Position: a (1 - e cos(E)) cos(v), y = a (1 - e cos(E)) sin(v); where a is the semi - major axis of the orbit and v is the true anomaly.

[0109]

[0110] Then convert the orbital plane coordinate system to the geocentric inertial coordinate system;

[0111]

[0112] where is the rotation matrix about the z - axis, is the rotation matrix about the x - axis, i represents the orbital inclination, represents the right ascension of the ascending node, represents the argument of perigee, ( , , ) represents the geocentric inertial coordinates of the satellite.

[0113] Convert the geocentric inertial coordinate system to the geocentric fixed coordinate system:

[0114]

[0115] where is the Greenwich mean sidereal time corresponding to the current time, ([[]] , , ) represents the geocentric fixed coordinates of the satellite.

[0116]

[0117]

[0118]

[0119] where is the mean radius of the Earth, represents the longitude of the current nearest ground station, represents the latitude of the current nearest ground station.

[0120] The distance between the satellite and the ground station ;

[0121] The azimuth ;

[0122] The elevation angle ;

[0123] Comprehensively calculate all the gains and losses during the process of the signal from the transmitting end to the receiving end:

[0124]

[0125] Among them, represents the received power, represents the transmitted power, represents the transmitting antenna gain, represents the receiving antenna gain, represents the free space path loss, represents the atmospheric propagation loss, represents other losses such as system loss and polarization loss.

[0126] Compare the received power with the communication threshold. If it is less than the communication threshold, the requirement is not met.

[0127] For example Figure 1 , the present invention provides a method for identifying and processing an abnormal handover code group of a satellite service system, including the following steps:

[0128] S1: The TT&C transponder of the satellite is in a normal working state and receives a handover backup code group command;

[0129] S2: The software checks whether there is a receiving fault in the uplink telecommand and further investigates the cause. If the relay channel is abnormal, the handover backup code group command is normally executed; otherwise, the command is regarded as an abnormal behavior and blocked;

[0130] S3: The software checks whether there is a fault in the downlink telemetry transmission and further investigates the cause. If the relay channel is abnormal, the handover backup code group command is normally executed; otherwise, the command is regarded as an abnormal behavior and blocked.

[0131] For example Figure 2 , the processing flowchart of the handover backup code group command caused by a receiving fault in the uplink telecommand is specifically as follows:

[0132] 1) The TT&C transponder of the first satellite is in a normal working state and receives a handover backup code group command. After responding, it will cause the transponder to work in the backup code group state, resulting in the non-response of the transponder;

[0133] 2) The software checks the voltage value of the telemetry information in the uplink locked state. The voltage value is -0.3V, which is between -0.15V and 0.5V, then it is confirmed that the signal is in the unlocked state. At the same time, the AGC telemetry signal is -140dBm. If it is not within the range of [-130, -42]dBm under normal conditions, further inspection reveals that the signal-to-noise ratio of telemetry A is 80, lower than the standard of 90, and the signal-to-noise ratio of telemetry B is 10, lower than the standard of 25. It is confirmed that there is a failure in the uplink telemetry reception;

[0134] 3) The ground increases the uplink power and attempts to transmit the remote control data packet from the high-orbit satellite to the first satellite again. The uplink telemetry reception channel of the first satellite does not respond. The software sends a baseband reset command to the unlock transponder, and the unlock transponder responds normally to the baseband reset command;

[0135] 4) The software sends a power-on / off command to the unlock transponder to restart the unlock transponder. After restarting, the voltage value of the unlock transponder returns to normal, and the signal-to-noise ratios of the AGC telemetry signal, telemetry A, and telemetry B return to normal. Then the reason for this situation is that the FPGA loading of the transponder is abnormal. The software regards the command to switch the backup code group as an abnormal behavior and masks this command.

[0136] Such as Figure 3 , the flow chart of the command to switch the backup code group caused by the downlink telemetry transmission failure is specifically as follows:

[0137] 1) The TT&C transponder of the first satellite is in a normal working state. After receiving the command to switch the backup code group and responding, it will cause the transponder to work in the backup code group state, resulting in the non-response of the transponder;

[0138] 2) After inspection, there is no signal received on the ground. The actual pointing direction of the antenna is confirmed by obtaining the current three-axis attitude angles (pitch, yaw, roll) from the attitude and orbit control subsystem. Using the installation offset angle of the antenna relative to the satellite body coordinate system, the specific position of the antenna pointing direction in the geocentric inertial coordinate system is calculated. According to the beam width, gain pattern, and field of view model of the antenna, its current pointing range is determined. According to the two-line element set (TLE) data of the satellite and the geographical coordinates of the ground station, the distance, azimuth, and elevation angle between the satellite and the ground station are calculated using the orbital dynamics model. Projecting the relative position of the ground station into the antenna field of view model, it is found that the ground station is located in the central region of the main lobe.

[0139] 3) Switch to the backup transponder to receive telemetry information. If the backup transponder does not receive the telemetry information and a remote control command is sent using the relay channel, and if the backup transponder also does not respond, then the software regards the command to switch the backup code group as a normal behavior and executes this command normally.

[0140] Those skilled in the art know that, in addition to implementing the systems, devices, and their respective modules provided by the present invention in the form of pure computer-readable program code, the method steps can be logically programmed to enable the systems, devices, and their respective modules provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, etc. to achieve the same program. Therefore, the systems, devices, and their respective modules provided by the present invention can be considered as a kind of hardware component, and the modules included therein for implementing various programs can also be regarded as the structures within the hardware component; the modules for implementing various functions can also be regarded as either software programs for implementing the method or the structures within the hardware component.

[0141] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for identifying and processing abnormal switching code groups in a satellite service system, characterized in that Including: Step 1: The TT&C transponder of the satellite is in a normal working state and receives a command for switching backup code groups. Step 2: Check through software whether there is a receiving fault in the uplink telecommand, and further investigate the cause. If the relay channel is abnormal, the command for switching backup code groups is normally executed; otherwise, the command is regarded as an abnormal behavior and blocked. Step 3: Check through software whether there is a fault in the downlink telemetry transmission, and further investigate the cause. If the relay channel is abnormal, the command for switching backup code groups is normally executed; otherwise, the command is regarded as an abnormal behavior and blocked.

2. The method for identifying and processing the star service system abnormal switching code group according to claim 1, wherein The TT&C transponder of the satellite is in a normal working state and receives a command for switching backup code groups. After response, the transponder works in the backup code group state, resulting in no response from the transponder. First, check through software whether there is a receiving fault in the uplink telecommand. The voltage value of the telemetry information in the uplink locked state is checked. If it is between -0.15V and 0.5V, it is confirmed that the signal is in an unlocked state. At the same time, it is also confirmed whether the AGC telemetry signal exceeds the normal range. If it is not within the range of [-130, -42] dBm, further check whether the signal-to-noise ratio telemetry is lower than the normal range. If so, it is confirmed that there is a receiving fault in the uplink telemetry.

3. The method for identifying and processing the abnormal switching code group of the satellite service system according to claim 1, wherein Increase the uplink power on the ground and try again to transmit the telecommand data packet from the geostationary satellite to the satellite. If it is normally received, it is judged that the antenna gain has decreased, and the software regards the command for switching backup code groups as an abnormal behavior and blocks the command. If the receiving anomaly still occurs after increasing the uplink power to the satellite, send a baseband reset instruction to the TT&C transponder through software. If the TT&C transponder does not execute the baseband reset command, decompose the received instruction. If there is missing data in the received instruction, or the received instruction is complete but the TT&C transponder delays in responding to the baseband reset instruction, it is judged that the receiving link of the transponder is abnormal. If the TT&C transponder normally executes the baseband reset instruction, further send a power-on / off instruction to the TT&C transponder to restart the TT&C transponder. If it returns to normal after restart, it is a situation of abnormal FPGA loading of the transponder. The software regards the command for switching backup code groups as an abnormal behavior and blocks the command. If the error still occurs after restart, use the relay channel to send a telecommand to test the TT&C transponder. If there is no response for a long time after sending the telecommand, check the link of the TT&C transponder and find that the telecommand is not received. Then the situation is that the relay channel is abnormal, and the software regards the command for switching backup code groups as a normal behavior and normally executes the command.

4. The method for identifying and processing the star service system abnormal switching code group according to claim 1, wherein Check through software whether there is a fault in the downlink telemetry transmission. If the situation of abnormal ground telemetry locking, weak or no received ground signal occurs, confirm whether the antenna field of view meets the TT&C requirements under the current satellite attitude. Obtain the current three-axis attitude angles from the attitude and orbit control subsystem to confirm the actual pointing direction of the antenna. Use the installation offset angle of the antenna relative to the satellite body coordinate system to calculate the specific position of the antenna pointing direction in the geocentric inertial coordinate system. According to the beam width, gain pattern and field of view model of the antenna, determine its current pointing range. Construct a combined quaternion from the three-axis attitude angles of the satellite , representing the rotation from the satellite body coordinate system to the geocentric inertial coordinate system, where the pitch angle about the y-axis is , the yaw angle about the z-axis is , and the roll angle about the x-axis is , then we have: X-axis rotation quaternion Quaternion of rotation about the y-axis z-axis rotation quaternion The specific position of the antenna pointing direction in the geocentric inertial coordinate system: ; wherein, represents the conjugate of a quaternion; represents the vector of the antenna direction in the satellite body coordinate system.

5. The method for identifying and processing the abnormal switching code group of the satellite service system according to claim 1, wherein According to the two-line element set (TLE) data of the satellite and the geographical coordinates of the ground station, the distance, azimuth, and elevation angle between the satellite and the ground station are calculated using the orbital dynamics model; the relative position of the ground station is projected into the antenna field-of-view model. If the ground station is located in the edge area or sidelobe range, all gains and losses during the signal transmission from the transmitter to the receiver are comprehensively calculated. If the requirements are not met, it is determined that the antenna pointing is inaccurate, and the software regards the switching of the backup code group command as an abnormal behavior and shields the command. If the ground station is located in the main lobe center area, the backup transponder is used to receive telemetry information. If the backup transponder successfully receives the telemetry information, the software regards the switching of the backup code group command as an abnormal behavior and shields the command. If the backup transponder fails to receive the telemetry information, the relay channel is used to send a telecommand. If the backup transponder also has no response, the software regards the switching of the backup code group command as a normal behavior and executes the command normally. Calculate the distance, azimuth, and elevation angle between the satellite and the ground station using the orbital dynamics model. Specifically: extract the orbital elements, obtain the satellite's orbital inclination, argument of perigee, right ascension of the ascending node, eccentricity, mean motion, and epoch time, and calculate the time difference between the current time and the TLE epoch time : Among them, represents the current moment, represents the TLE epoch time, a(t) is the magnitude of the acceleration at the current moment; k is an adjustment factor, shortening the step length at the perigee and increasing the step length at the apogee; Use Kepler's equation to calculate the eccentric anomaly from the mean anomaly: where M is the mean anomaly, E is the eccentric anomaly, and e is the orbital eccentricity. Solve for E using the iterative method: ; Iterate continuously until the residual ( - ) is less than ; and are the results of two consecutive iterations; In the orbital plane, calculate the position ( , y) and velocity of the satellite: where a is the semi-major axis of the orbit and v is the true anomaly, is the gravitational parameter of the Earth; Then, the orbital plane coordinate system is converted to the geocentric inertial coordinate system, and all gains and losses during the signal transmission from the transmitter to the receiver are comprehensively calculated. Among them, represents the received power, represents the transmitted power, represents the transmitting antenna gain, represents the receiving antenna gain, represents the free space path loss, represents the atmospheric propagation loss, represents the system loss and polarization loss; compare the received power with the communication threshold, if it is less than the communication threshold, the requirement is not met.

6. A star service system abnormal switching code group recognition and processing system, characterized in that, Including: Module M1: The satellite's TT&C transponder is in a normal working state and receives the switching backup code group command. Module M2: The software checks whether there is a reception failure in the uplink telecommand and further investigates the cause. If the relay channel is abnormal, the switching backup code group command is executed normally; otherwise, the command is regarded as an abnormal behavior and shielded. Module M3: The software checks whether there is a failure in the downlink telemetry transmission and further investigates the cause. If the relay channel is abnormal, the switching backup code group command is executed normally; otherwise, the command is regarded as an abnormal behavior and shielded.

7. The star service system abnormal switching code group identification and processing system according to claim 6, characterized in that, The satellite's TT&C transponder is in a normal working state and receives the switching backup code group command. After responding, the transponder operates in the backup code group state, resulting in no response from the transponder. The software first checks whether there is a reception failure in the uplink telecommand, and the voltage value of the telemetry information in the uplink locked state is checked. If it is between -0.15V and 0.5V, it is confirmed that the signal is in an unlocked state; at the same time, it is also confirmed whether the AGC telemetry signal exceeds the normal range. If it is not in the range of [-130, -42] dBm, the signal-to-noise ratio telemetry is further checked to see if it is lower than the normal range. If so, it is confirmed that there is a failure in the uplink telemetry reception.

8. The star service system abnormal switching code group identification and processing system according to claim 6, characterized in that, Increase the uplink power to the ground and try to transmit the telecommand data packet from the high-orbit satellite to the satellite again. If it is received normally, it is determined that the antenna gain has decreased, and the software regards the switching of the backup code group command as an abnormal behavior and shields the command. If the reception is still abnormal after increasing the uplink power to the satellite, the software sends a baseband reset command to the TT&C transponder. If the TT&C transponder does not execute the baseband reset command, the received command is decomposed. If there is missing data in the received command or the received command is complete but the TT&C transponder has a delayed response to the baseband reset command, it is determined that the transponder reception link is abnormal. If the TT&C transponder normally executes the baseband reset instruction, further send the power-on / off instruction to the TT&C transponder to restart it. If it returns to normal after restart, it indicates a situation where the FPGA loading of the transponder is abnormal. The software regards the switching backup code group command as an abnormal behavior and masks this command. If an error still occurs after restart, use the relay channel to send a telecommand to test the TT&C transponder. If there is no response for a long time after sending the telecommand and it is found that the telecommand has not been received by checking the link of the TT&C transponder, it indicates that the relay channel is abnormal. The software regards the switching backup code group command as a normal behavior and executes this instruction normally.

9. The star service system abnormal switching code group recognition and processing system according to claim 6, characterized in that Check whether the downlink telemetry transmission is faulty through software. If the ground telemetry lock is abnormal or the ground received signal is weak or there is no signal, confirm whether the antenna field of view meets the TT&C requirements under the current satellite attitude. Obtain the current three-axis attitude angles from the attitude and orbit control subsystem to confirm the actual pointing direction of the antenna. Use the installation offset angle of the antenna relative to the satellite body coordinate system to calculate the specific position of the antenna pointing direction in the geocentric inertial coordinate system. Determine its current pointing range according to the antenna beam width, gain pattern, and field of view model. Construct a combined quaternion from the three-axis attitude angles of the satellite , representing the rotation from the satellite body coordinate system to the geocentric inertial coordinate system, where the pitch angle about the y-axis is , the yaw angle about the z-axis is , and the roll angle about the x-axis is . Then we have: X-axis rotation quaternion Quaternion of rotation about the y-axis z-axis rotation quaternion Specific position of the antenna pointing direction in the geocentric inertial coordinate system: ; Among them, represents the conjugate of the quaternion; represents the vector of the antenna direction in the satellite body coordinate system.

10. The star mission system abnormal switching code group recognition and processing system according to claim 6, characterized in that Calculate the distance, azimuth, and elevation angle between the satellite and the ground station using the orbital dynamics model based on the two-line element (TLE) data of the satellite and the geographical coordinates of the ground station. Project the relative position of the ground station into the antenna field of view model. If the ground station is located in the edge area or sidelobe range, comprehensively calculate all the gains and losses during the signal transmission from the transmitter to the receiver. If the requirements are not met, it is determined that the antenna pointing is inaccurate. The software regards the switching backup code group command as an abnormal behavior and masks the instruction. If the ground station is located in the main lobe center area, use the backup transponder to receive telemetry information. If the backup transponder successfully receives the telemetry information, the software regards the switching backup code group command as an abnormal behavior and masks the instruction. If the backup transponder cannot receive the telemetry information, use the relay channel to send a telecommand. If the backup transponder also has no response, the software regards the switching backup code group command as a normal behavior and executes the instruction normally. Calculate the distance, azimuth, and elevation angle between the satellite and the ground station using the orbital dynamics model. Specifically: extract the orbital elements, obtain the satellite's orbital inclination, argument of perigee, right ascension of the ascending node, eccentricity, mean motion, and epoch time, and calculate the time difference between the current time and the TLE epoch time : Among them, represents the current moment, represents the TLE epoch time, a(t) is the magnitude of the acceleration at the current moment; k is an adjustment factor, shortening the step length at the perigee and increasing the step length at the apogee; Use Kepler's equation to calculate the eccentric anomaly from the mean anomaly: where M is the mean anomaly, E is the eccentric anomaly, and e is the orbital eccentricity. Solve for E using the iterative method: ; Iterate continuously until the residual ( - ) is less than ; and are the results of two consecutive iterations; In the orbital plane, calculate the position ( , y) and velocity of the satellite: where a is the semi-major axis of the orbit and v is the true anomaly, is the gravitational parameter of the Earth; Then convert the orbital plane coordinate system to the geocentric inertial coordinate system and comprehensively calculate all the gains and losses during the signal transmission from the transmitter to the receiver. Among them, represents the received power, represents the transmitted power, represents the transmitting antenna gain, represents the receiving antenna gain, represents the free space path loss, represents the atmospheric propagation loss, represents the system loss and polarization loss; compare the received power with the communication threshold, if it is less than the communication threshold, the requirement is not met.

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