Tiantong satellite communication antenna tracking control method and system

Abstract

The invention discloses a Tiantong satellite communication antenna tracking control method and system, and belongs to the technical field of communication. The method comprises the following steps: receiving orientation information of a GNSS positioning orientation receiver, and determining heading attitude information and heading information states of an antenna in combination with heading attitude information of an inertial heading attitude module; establishing a priority queue of the signal frequency points; and determining a tracking control mode according to the course information state, driving an antenna beam to point to a satellite, and updating a priority queue of signal frequency points according to a signal effective state. Aiming at the defects that a double-antenna positioning and orientation module is easily interfered and the course precision is poor due to a short baseline, a signal searching and tracking mode based on a frequency correction channel is added, a searching priority queue of signal frequency points is established, and the searching priority queue comprises a preset common frequency point list and an automatically updated available frequency point list; the satellite capturing speed of the Tiantong satellite communication antenna is effectively improved, and the tracking precision and reliability of the Tiantong satellite communication antenna are improved.

Description

Technical Field

[0001] This invention relates to the field of communication technology, specifically to a method and system for tracking and controlling a Tiantong satellite communication antenna. Background Technology

[0002] The Tiantong-1 satellite mobile communication system is an independently developed and constructed satellite mobile communication system in China. Its coverage area mainly includes China and surrounding regions, the Middle East, Africa, and most of the Pacific and Indian Oceans. It serves various mobile users, including vehicles, aircraft, ships, and individuals, providing stable and reliable mobile communication services around the clock for personal communication, maritime transport, deep-sea fishing, air rescue, tourism, and scientific research. It supports voice, SMS, and data services.

[0003] The Tiantong-1 satellite lacks a fixed-frequency beacon signal. Satellite communication antennas installed on mobile vehicles such as cars and ships typically employ dual-antenna positioning and orientation modules, coupled with MEMS inertial systems for pointing and tracking. When the dual-antenna positioning and orientation modules fail to orient themselves due to obstruction, interference, or other reasons, the satellite communication antenna cannot function properly. Furthermore, when the baseline of the dual-antenna positioning and orientation module is short, the heading error is large, resulting in low tracking accuracy for the satellite communication antenna. Summary of the Invention

[0004] This invention addresses the shortcomings of dual-antenna positioning and orientation modules, which are susceptible to interference, and the poor heading accuracy caused by short baselines. It proposes a tracking control method and system for Tiantong satellite communication antennas. This invention adds a signal search and tracking mode based on the Frequency Correction Channel (FCCH), establishes a priority queue for signal frequency points, including a preset list of commonly used frequencies and an automatically updated list of available frequencies. This effectively improves the satellite acquisition speed of the Tiantong satellite communication antenna and enhances its tracking accuracy and reliability.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for tracking and controlling a Tiantong satellite communication antenna includes the following steps:

[0007] Step 1: Receive orientation information from the GNSS positioning and orientation receiver and attitude information from the inertial attitude module to determine the antenna's attitude and heading information status; wherein, the orientation information from the GNSS positioning and orientation receiver includes longitude λ and latitude. heading ψ G The attitude information of the inertial attitude module includes the heading ψ I θ (tip) and g (rollback);

[0008] Step 2: Establish a priority queue for signal frequencies. The available frequency numbers that are constantly updated during antenna operation have the highest priority, followed by the commonly used frequency numbers preset inside the antenna, and finally the remaining frequency numbers of the Tiantong satellite.

[0009] Step 3: Perform antenna tracking control based on the heading information status:

[0010] If the heading information status is valid, immediately execute procedure one;

[0011] If the heading information status is invalid, immediately execute procedure two;

[0012] When the heading information status changes from invalid to valid, process one is executed immediately;

[0013] When the heading information status changes from valid to invalid, timing starts immediately. A time threshold T is set according to the heading drift rate of the inertial attitude module. Process one is executed within the time threshold T, and process two is executed after the time threshold T is exceeded.

[0014] Process 1:

[0015] Step A01, the antenna tracking control mode is pointing tracking, using ψ G Correction ψ I The heading ψ of the inertial attitude module is adopted. I The pitch θ and tilt g information drive the antenna beam to point to the satellite's theoretical position, which is calculated using the following formula:

[0016]

[0017]

[0018] In the formula, A and E are the satellite's theoretical azimuth and elevation positions, respectively, H is the satellite's geocentric altitude, and l S , H S These are the longitude, latitude, and geocentric altitude of the antenna's location, respectively.

[0019] Step A02: Dequeue the frequency points in the priority queue in sequence, set up the FCCH signal receiver, collect the signal strength of the corresponding frequency point, including field strength, power, and signal-to-noise ratio, and determine the signal validity status based on this, i.e., determine whether the satellite signal is locked; if the signal is valid, set the corresponding frequency point as an available frequency point; if the signal is invalid, continue to execute step A02 until the priority queue is cleared.

[0020] Step A03: Set the last valid frequency point number of the signal into the FCCH signal receiver, keep the antenna beam pointing to the theoretical position of the satellite, and end process one;

[0021] Step Two:

[0022] Step B01: Dequeue the frequency points in the priority queue in sequence, set up the FCCH signal receiver, drive the antenna beam to keep the elevation angle constant, perform an azimuth scan, and collect the signal strength output by the FCCH signal receiver in real time, including field strength, power, and signal-to-noise ratio, and determine the signal validity status based on this, i.e., determine whether the satellite signal is locked.

[0023] Step B02: If the signal is valid, immediately stop the azimuth scan and correct the ψ angle using satellite theoretical angle correction. I Proceed to step B03; if the signal is invalid, continue to step B01 until the priority queue is cleared, and end process two.

[0024] Step B03: Continue to dequeue the frequency points in the priority queue in sequence, set the FCCH signal receiver, collect the signal strength of the corresponding frequency point, including field strength, power, and signal-to-noise ratio, and determine the signal validity status based on this, i.e., whether the satellite signal is locked; if the signal is valid, set the corresponding frequency point as an available frequency point; if the signal is invalid, continue to execute step B03 until the priority queue is cleared, and end process two.

[0025] A tracking and control system for a Tiantong satellite communication antenna includes a Tiantong satellite communication antenna, a GNSS positioning and orientation receiver, an inertial attitude module, and an FCCH signal receiver. The Tiantong satellite communication antenna is provided with an embedded control unit, which is used to execute the method described above.

[0026] The beneficial effects of adopting the above technical solution are as follows:

[0027] 1. To address the shortcomings of dual-antenna positioning and orientation modules being susceptible to interference and the difference in heading longitude caused by short baselines, this invention adds a signal search and tracking mode based on the Frequency Correction Channel (FCCH), thereby increasing the tracking accuracy and reliability of the Tiantong satellite communication antenna.

[0028] 2. This invention establishes a priority queue for searching signal frequencies, which includes a preset list of commonly used frequencies and an automatically updated list of available frequencies, effectively improving the satellite acquisition speed of the Tiantong satellite communication antenna. Attached Figure Description

[0029] Figure 1 This is a block diagram of the Tiantong satellite communication antenna in an embodiment of the present invention;

[0030] Figure 2 This is a general flowchart of the tracking control method in this embodiment of the invention;

[0031] Figure 3This is a flowchart of the tracking control process in this embodiment of the invention when GNSS orientation information is valid and changes from valid to invalid.

[0032] Figure 4 This is a flowchart of the tracking control process when GNSS orientation information is invalid and then becomes valid in an embodiment of the present invention. Detailed Implementation

[0033] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] A tracking and control system for a Tiantong satellite communication antenna includes an embedded control unit in the Tiantong satellite communication antenna, as well as a GNSS positioning and orientation receiver, an inertial attitude module, and an FCCH signal receiver. The antenna system composition is described in [reference needed]. Figure 1 .

[0035] See Figure 2 The embedded control unit is used to execute the following Tiantong satellite communication antenna tracking control method:

[0036] (1) Receive orientation information from GNSS positioning and orientation receiver, and combine it with attitude information from inertial attitude module to determine the attitude and heading information status of antenna;

[0037] (2) Establish a priority queue of signal frequency points based on the pre-stored commonly used frequency point numbers and the priority search frequency point numbers;

[0038] (3) Determine the tracking control mode based on the heading information status, drive the antenna beam to point to the satellite, and update the priority queue of the signal frequency points according to the signal validity status.

[0039] Furthermore, the GNSS positioning and orientation receiver is a GPS positioning and orientation receiver or a BeiDou positioning and orientation receiver.

[0040] The specific method for step (1) is as follows:

[0041] Receive orientation information (not limited to HDT, ORI, GGA, etc.) from GNSS positioning and orientation receivers, including but not limited to longitude λ and latitude. heading ψ G and heading information status F G Receives information from the inertial attitude module, including but not limited to heading ψ I θ (tilt) and γ (slope).

[0042] The specific method for step (2) is as follows:

[0043] Read the commonly used frequency point number array A1 of length L1 from the pre-stored parameters, and read the available frequency point number array A2 of length L2 from the pre-stored parameters. Generate a priority queue with the priority order as A2, A1, and remaining frequency points, where 1 ≤ L1 + L2 ≤ 1389. A1 is the commonly used frequency point number preset inside the antenna and can be manually changed. A2 is the available frequency point number that is continuously updated during antenna operation. The signal frequency corresponding to the frequency point number is calculated according to the following formula:

[0044]

[0045] Where n is the frequency point number, which is an integer ranging from 1 to 1389.

[0046] The specific method for step (3) is as follows:

[0047] (301) Based on the heading information status F in step (1) G There are four possible scenarios:

[0048] (3011) Heading Information Status F G If it is valid, immediately execute steps (302), (303), and (304), see below. Figure 3 ;

[0049] (3012) Heading Information Status F G If invalid, immediately execute steps (305) and (306), see below. Figure 3 ;

[0050] (3013) Heading Information Status F G When switching from invalid to valid, steps (302), (303), and (304) are executed immediately. See below. Figure 4 ;

[0051] (3014) Heading Information Status F G When switching from valid to invalid, immediately execute step (307), see [link]. Figure 4 ;

[0052] (302) The antenna tracking control method is pointing tracking, utilizing ψ G Correction ψ I The correction method depends on the installation position relationship between the GNSS positioning and orientation receiver and the inertial attitude module. Typically, the baseline of the GNSS positioning and orientation receiver is aligned with the pitch axis of the antenna. When the heading information state F... G When valid, use the following formula to correct ψ. I :

[0053] ψ I =ψ G -90°

[0054] The heading ψ of the inertial attitude module is adopted. I The pitch θ and tilt γ information drive the antenna beam to point to the satellite's theoretical position, which is calculated using the following formula:

[0055]

[0056]

[0057] In the formula, A and E are the theoretical azimuth and elevation positions of the satellite, respectively, and H... S λ is the geocentric altitude of the satellite. S , H S These are the longitude, latitude, and geocentric altitude of the antenna's location, respectively.

[0058] (303) Frequency points in the priority queue are dequeued in sequence. The FCCH signal receiver is set up to collect the signal strength of the corresponding frequency point, including but not limited to field strength, power, and signal-to-noise ratio. Based on this, the signal validity status is determined, i.e., whether the satellite signal is locked. If the signal is valid, the corresponding frequency point number is written into the available frequency point number array A2. If the signal is invalid, (303) is executed again until the priority queue is cleared.

[0059] (304) Set the last valid frequency point of the signal into the FCCH signal receiver to keep the antenna beam pointing to the theoretical position of the satellite;

[0060] (305) The frequency points in the priority queue are dequeued in sequence, the FCCH signal receiver is set up, the antenna beam is driven to keep the elevation angle unchanged, the azimuth is scanned around, and the signal strength output by the FCCH signal receiver is collected in real time, including but not limited to field strength, power and signal-to-noise ratio, and the effective status of the signal is determined accordingly, i.e. whether the satellite signal is locked.

[0061] (306) If the signal is valid, immediately stop the azimuth scan and use the satellite theoretical angle correction ψ. I Proceed to step (303), and terminate after step (303) is completed. If the signal is invalid, continue executing step (305) until the priority queue is cleared;

[0062] (307) Heading Information Status F G Timing begins when the signal switches from active to inactive, with a time threshold T set based on the heading drift rate of the inertial attitude module. For example, if the heading drift rate of the inertial attitude module is 2° / min and the antenna beamwidth is approximately 20°, a time threshold T = 3min is set to ensure antenna tracking accuracy. Heading information state F GThe timer starts when the device switches from valid to invalid. If the time is within the time threshold, (302), (303), and (304) are executed. If the time threshold is exceeded, (305) and (306) are executed.

[0063] In summary, this invention addresses the shortcomings of dual-antenna positioning and orientation modules being susceptible to interference and the poor heading accuracy caused by short baselines by adding a signal search and tracking mode based on the Frequency Correction Channel (FCCH). It establishes a priority queue for searching signal frequencies, including a preset list of commonly used frequencies and an automatically updated list of available frequencies. This effectively improves the satellite acquisition speed of the Tiantong satellite communication antenna and increases its tracking accuracy and reliability, representing a significant improvement over existing technologies.

Claims

1. A tracking and control method for a Tiantong satellite communication antenna, characterized in that, Includes the following steps: Step 1: Receive orientation information from the GNSS positioning and orientation receiver and attitude information from the inertial attitude module to determine the antenna's attitude and heading information status; wherein, the orientation information from the GNSS positioning and orientation receiver includes longitude λ and latitude. heading ψ G The attitude information of the inertial attitude module includes the heading ψ I θ (pitch) and γ (roll). Step 2: Establish a priority queue for signal frequencies. The available frequency numbers that are constantly updated during antenna operation have the highest priority, followed by the commonly used frequency numbers preset inside the antenna, and finally the remaining frequency numbers of the Tiantong satellite. Step 3: Perform antenna tracking control based on the heading information status: If the heading information status is valid, immediately execute procedure one; If the heading information status is invalid, immediately execute procedure two; When the heading information status changes from invalid to valid, process one is executed immediately; When the heading information status changes from valid to invalid, timing starts immediately. A time threshold T is set according to the heading drift rate of the inertial attitude module. Process one is executed within the time threshold T, and process two is executed after the time threshold T is exceeded. Process 1: Step A01, the antenna tracking control mode is pointing tracking, using ψ G Correction ψ I The heading ψ of the inertial attitude module is adopted. I The pitch θ and tilt γ information drive the antenna beam to point to the satellite's theoretical position, which is calculated using the following formula: In the formula, A and E are the theoretical azimuth and elevation positions of the satellite, respectively, H is the geocentric altitude of the satellite, and λ is the theoretical elevation position of the satellite. S , H S These are the longitude, latitude, and geocentric altitude of the antenna's location, respectively. Step A02: Dequeue the frequency points in the priority queue in sequence, set up the FCCH signal receiver, collect the signal strength of the corresponding frequency point, including field strength, power, and signal-to-noise ratio, and determine the signal validity status based on this, i.e., determine whether the satellite signal is locked; if the signal is valid, set the corresponding frequency point as an available frequency point; if the signal is invalid, continue to execute step A02 until the priority queue is cleared. Step A03: Set the last valid frequency point number of the signal into the FCCH signal receiver, keep the antenna beam pointing to the theoretical position of the satellite, and end process one; Step Two: Step B01: Dequeue the frequency points in the priority queue in sequence, set up the FCCH signal receiver, drive the antenna beam to keep the elevation angle constant, perform an azimuth scan, and collect the signal strength output by the FCCH signal receiver in real time, including field strength, power, and signal-to-noise ratio, and determine the signal validity status based on this, i.e., determine whether the satellite signal is locked. Step B02: If the signal is valid, immediately stop the azimuth scan and correct the ψ angle using satellite theoretical angle correction. I Proceed to step B03; if the signal is invalid, continue to step B01 until the priority queue is cleared, and end process two. Step B03: Continue to dequeue the frequency points in the priority queue in sequence, set the FCCH signal receiver, collect the signal strength of the corresponding frequency point, including field strength, power, and signal-to-noise ratio, and determine the signal validity status based on this, i.e., whether the satellite signal is locked; if the signal is valid, set the corresponding frequency point as an available frequency point; if the signal is invalid, continue to execute step B03 until the priority queue is cleared, and end process two.

2. A tracking and control system for a Tiantong satellite communication antenna, comprising a Tiantong satellite communication antenna, characterized in that, It also includes a GNSS positioning and orientation receiver, an inertial attitude module, and an FCCH signal receiver. The Tiantong satellite communication antenna is equipped with an embedded control unit, which is used to execute the method as described in claim 1.

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