Low-orbit phased array terminal satellite capture and inertial navigation real-time calibration method, equipment, system and medium

Abstract

The invention discloses a low-orbit phased array terminal satellite capture and inertial navigation real-time calibration method, device and system and a medium, and belongs to the field of satellite mobile communication, and the method comprises the following steps: after a satellite is successfully captured and stabilized, an antenna enters a satellite tracking state, and inertial navigation data is continuously calibrated in the tracking state; wherein the phased-array antenna is divided into four array planes, namely an A array plane, a B array plane, a C array plane and a D array plane, and the receiving powers of the four array planes respectively correspond to the power PA, the power PB, the power PC and the power PD; the antenna is provided with four power detection circuits which are used for detecting the combined receiving power of the four array plane combinations, the combined receiving power corresponds to PA and PB, PC and PD, PA and PC, PB and PD, and the antenna beam pointing error is calculated and corrected. According to the invention, the attitude data can be calibrated in real time by receiving the signal, so that the cost and the design complexity of the phased-array antenna are reduced.

Description

Technical Field

[0001] This invention relates to the field of satellite mobile communication, and more specifically, to a method, device, system, and medium for real-time calibration of satellite acquisition and inertial navigation for a low-Earth orbit phased array terminal. Background Technology

[0002] Low-Earth orbit (LEO) satellite phased array terminals are the core equipment for LEO internet constellations to achieve space-to-ground communication connections. The mainstream technology of phased array terminals revolves around the phased array antenna surface, combined with dual GPS / BeiDou orientation modules and an inertial navigation module, enabling rapid satellite alignment and network access in any state. Dual GPS / BeiDou provides high-precision position and azimuth attitude information, while the inertial navigation module, including a three-axis inclinometer and a three-axis gyroscope, provides pitch and roll attitude information. This combination ensures that even during high-speed movement (such as vehicle-mounted or ship-mounted) or complex attitude changes, the terminal can still achieve microsecond-level rapid satellite alignment and stable network access, meeting the "low latency, wide coverage" communication requirements of LEO constellations.

[0003] However, current solutions suffer from significant technical bottlenecks: dual GPS / BeiDou modules are expensive and bulky, complicating the planar and vertical design of satellite terminals. More critically, low-Earth orbit satellite communication signals are prone to interfering with GPS / BeiDou positioning signals, causing minor issues like jumps in positioning and azimuth data and decreased accuracy, or even signal loss, directly impacting satellite alignment accuracy. Furthermore, to avoid interference, the GPS / BeiDou antenna must be physically isolated from the phased array antenna. This typically requires cutting away sections of the phased array antenna surface to install the positioning antenna, which not only compromises the integrity of the array surface and increases the complexity of beamforming algorithms but also reduces the effective radiating area of ​​the antenna. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method, device, system and medium for real-time calibration of low-orbit phased array terminal satellite acquisition and inertial navigation. It can calibrate attitude data in real time by receiving signals, thereby reducing costs and the complexity of phased array antenna design.

[0005] The objective of this invention is achieved through the following solution: A method for real-time satellite acquisition and inertial navigation calibration of a low-Earth orbit phased array terminal includes the following steps: Satellite acquisition: Satellites are acquired using a phased array antenna on a satellite terminal with a single GPS / BeiDou positioning module; Satellite Tracking: After successful satellite acquisition and stabilization, the antenna enters satellite tracking mode, continuously calibrating the inertial navigation data. The phased array antenna is divided into four arrays: A, B, C, and D. The received power of each array corresponds to PA, PB, PC, and PD, respectively. The antenna is equipped with four power detection circuits to detect the combined received power of the four arrays, corresponding to PA and PB, PC and PD, PA and PC, and PB and PD, respectively. The antenna beam pointing error is calculated and corrected as follows: When the normalized azimuth difference = ((PA+PC)-(PB+PD)) / (PA+PB+PC+PD) = 0, it indicates that the beam azimuth is pointing correctly; otherwise, the beam pointing is corrected in the direction of reducing the difference. When the normalized off-axis difference = ((PA+PB)-(PC+PD)) / (PA+PB+PC+PD) = 0, it indicates that the beam off-axis angle is pointing correctly; otherwise, the beam direction is corrected in the direction of reducing the difference.

[0006] Furthermore, it also includes the following steps: The PID algorithm is used to control the azimuth difference and off-axis difference within a set range to ensure the beam pointing accuracy of the phased array antenna.

[0007] Furthermore, the step of using a PID algorithm to control the azimuth difference and off-axis difference within a set range specifically includes the following sub-steps: Let Kp, Ki, and Kd be the proportional, derivative, and integral coefficients of the PID algorithm, Δ be the normalized azimuth difference or off-axis difference, and t be the time interval for periodically measuring the received signal. Then: Adjustment angle = Kp×△ + Ki×△×t + Kd×△ / t; By adjusting the three parameters Kp, Ki, and Kd, rapid and accurate control can be achieved.

[0008] Furthermore, the inertial navigation module of the satellite terminal with the single GPS / BeiDou positioning module is a 6-axis inertial navigation module.

[0009] A satellite terminal device for performing the low-Earth orbit phased array terminal satellite acquisition and inertial navigation real-time calibration method as described in any of the preceding claims.

[0010] An electronic system comprising the satellite terminal equipment described above.

[0011] A readable storage medium storing a computer program, the computer program being loaded by a processor and executed as described in any of the preceding claims, for low-Earth orbit phased array terminal satellite acquisition and inertial navigation real-time calibration method.

[0012] The beneficial effects of this invention include: The present invention does not require a dual GPS / BeiDou architecture, thus reducing costs; it can use a 6-axis inertial navigation system by calibrating attitude data in real time through received signals; and it does not require chamfering the phased array antenna, thus reducing the complexity of phased array antenna design. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the phased array antenna array layout according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the combined received power detection of four arrays in an embodiment of the present invention; Figure 3 This is a flowchart illustrating the satellite acquisition process according to an embodiment of the present invention; Figure 4 This is a flowchart of the inertial navigation calibration process according to an embodiment of the present invention. Detailed Implementation

[0015] All features disclosed in all embodiments of this specification, or steps in all methods or processes implied in the disclosure, may be combined and / or extended or replaced in any way, except for mutually exclusive features and / or steps.

[0016] In this invention, compared with existing satellite terminals, at least the following technical problems are solved: 1) The expensive dual GPS / BeiDou module has been eliminated and replaced with a lower-cost single GPS / BeiDou positioning module. At the same time, the inertial navigation module can use a lower-cost 6-axis inertial navigation module. 2) The phased array antenna is divided into 4 regions, and each region couples out a receiving signal. The strength of the 4 received signals (RSSI) can be detected by an integrated chip circuit of amplification / gain control / power detection. The antenna beam pointing error can be calculated by using the magnitude of these 4 RSSI signals and a specific method, thereby achieving the functions of satellite acquisition and real-time beam pointing calibration. 3) It avoids the inconvenience caused by the phased array antenna being cut off due to the installation of two positioning antennas, which would otherwise lead to many problems in the design and production of the phased array antenna; 4) It greatly reduces the interference problem between phased array antennas and positioning antennas.

[0017] More specifically, stable access to a low-Earth orbit (LEO) satellite network by a phased array antenna generally involves two steps: satellite acquisition and satellite tracking. After powering on, the phased array antenna enters satellite acquisition mode. For a phased array antenna, the beam pointing needs to be determined at two angles: azimuth and off-axis angle. The phased array antenna can calculate these two angles based on the LEO satellite's ephemeris, thus completing satellite acquisition. Once the satellite signal is stably acquired (network access successful), the phased array antenna enters the satellite tracking phase. During tracking, inertial navigation data needs to be calibrated to eliminate the accumulation of errors caused by long-term sensor drift.

[0018] Satellite Acquisition: When the low-Earth orbit phased array antenna acquires a satellite, it first calculates the theoretical beam pointing parameters (two angles in the geographic coordinate system) of the target satellite relative to the terminal using the satellite ephemeris data and an orbital dynamics model. The terminal also needs to calculate the above two angles in the carrier coordinate system based on the real-time pitch and roll angle data collected by the inertial navigation system (integrating inclinometer and gyroscope) to correct its own attitude error and ensure beam pointing accuracy. The azimuth angle adopts a 360° step scanning strategy: the phased array antenna scans in all directions with the theoretical azimuth angle as the center, at a preset step size (e.g., 3° / step). After scanning each angle, the beam pointing is adjusted through the TR component to receive satellite signals in that direction. At the same time, the signal processing module monitors the echo signal strength in real time. When the signal strength of a certain scanning angle exceeds a preset threshold (to avoid noise interference), the baseband demodulation process is triggered. The baseband module performs carrier synchronization, symbol synchronization, and data decoding on the signal. If key information such as the communication frame structure is successfully demodulated, the satellite is considered successfully acquired. The antenna then stops scanning and locks onto the beam direction, laying the foundation for subsequent fine tracking and communication link establishment. At this point, the initial angles of azimuth and off-axis are determined.

[0019] Satellite Tracking: After successful satellite acquisition and stabilization for a certain period, the antenna enters satellite tracking mode. During tracking, inertial navigation data needs continuous calibration to eliminate accumulated errors. The phased array antenna is divided into four array surfaces: A, B, C, and D, as shown below. Figure 1 As shown: The received power of the four arrays are PA, PB, PC, and PD, respectively. The antenna is equipped with four power detection circuits to detect the combined received power of the four array combinations: PA+PB, PC+PD, PA+PC, and PB+PD. Figure 2 As shown.

[0020] When the normalized azimuth difference = ((PA+PC)-(PB+PD)) / (PA+PB+PC+PD) = 0, it indicates that the beam azimuth is pointing correctly; otherwise, the beam pointing should be corrected in the direction that reduces the difference.

[0021] When the normalized off-axis difference = ((PA+PB)-(PC+PD)) / (PA+PB+PC+PD) = 0, it indicates that the beam off-axis angle is pointing correctly; otherwise, the beam direction should be corrected in the direction of reducing the difference.

[0022] Using the above method, as long as there is a satellite receiving signal, the beam pointing can be corrected in real time, and the attitude data of the inertial navigation system can be corrected to eliminate the influence of zero drift.

[0023] Both azimuth difference and off-axis difference can be controlled using a PID algorithm. This allows the difference to be quickly controlled within a small range, ensuring the beam pointing accuracy of the phased array antenna. Let Kp, Ki, and Kd be the proportional, derivative, and integral coefficients of the PID algorithm, Δ be the normalized azimuth difference or off-axis difference, and t be the time interval for periodically measuring the received signal. Then: Adjustment angle = Kp × Δ + Ki × Δ × t + Kd × Δ / t By adjusting the three parameters Kp, Ki, and Kd, rapid and accurate control can be achieved.

[0024] The satellite acquisition process using this invention is as follows: Figure 3 As shown; the inertial navigation calibration process applying the present invention is as follows: Figure 4 As shown.

[0025] As another embodiment of the present invention, a satellite terminal device is provided for performing the low-orbit phased array terminal satellite acquisition and inertial navigation real-time calibration method as described above.

[0026] As another embodiment of the present invention, an electronic system is provided, including the satellite terminal equipment described above.

[0027] The units described in the embodiments of the present invention can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0028] According to one aspect of the present invention, a computer program product or computer program is provided, the computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and executes the computer instructions, causing the computer device to perform the methods provided in the various optional implementations described above.

[0029] In another aspect, embodiments of the present invention also provide a computer-readable medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the methods described in the above embodiments.

Claims

1. A method for real-time satellite acquisition and inertial navigation calibration of a low-Earth orbit phased array terminal, characterized in that, Includes the following steps: Satellite acquisition: Satellites are acquired using a phased array antenna on a satellite terminal with a single GPS / BeiDou positioning module; Satellite Tracking: After successful satellite acquisition and stabilization, the antenna enters satellite tracking mode, continuously calibrating the inertial navigation data. The phased array antenna is divided into four arrays: A, B, C, and D. The received power of each array corresponds to PA, PB, PC, and PD, respectively. The antenna is equipped with four power detection circuits to detect the combined received power of the four arrays, corresponding to PA and PB, PC and PD, PA and PC, and PB and PD, respectively. The antenna beam pointing error is calculated and corrected as follows: When the normalized azimuth difference = ((PA+PC)-(PB+PD)) / (PA+PB+PC+PD) = 0, it indicates that the beam azimuth is pointing correctly; otherwise, the beam pointing is corrected in the direction of reducing the difference. When the normalized off-axis difference = ((PA+PB)-(PC+PD)) / (PA+PB+PC+PD) = 0, it indicates that the beam off-axis angle is pointing correctly; otherwise, the beam direction is corrected in the direction of reducing the difference.

2. The method for real-time satellite acquisition and inertial navigation calibration of a low-Earth orbit phased array terminal according to claim 1, characterized in that, It also includes the following steps: The PID algorithm is used to control the azimuth difference and off-axis difference within a set range to ensure the beam pointing accuracy of the phased array antenna.

3. The method for real-time satellite acquisition and inertial navigation calibration of a low-Earth orbit phased array terminal according to claim 2, characterized in that, The step of using a PID algorithm to control the azimuth difference and off-axis difference within a set range specifically includes the following sub-steps: Let Kp, Ki, and Kd be the proportional, derivative, and integral coefficients of the PID algorithm, Δ be the normalized azimuth difference or off-axis difference, and t be the time interval for periodically measuring the received signal. Then: Adjustment angle = Kp×△ + Ki×△×t + Kd×△ / t; By adjusting the three parameters Kp, Ki, and Kd, rapid and accurate control can be achieved.

4. The method for real-time satellite acquisition and inertial navigation calibration of a low-Earth orbit phased array terminal according to claim 1, characterized in that, The satellite terminal with the single GPS / BeiDou positioning module uses a 6-axis inertial navigation module.

5. A satellite terminal device, characterized in that, The method for performing low-Earth orbit phased array terminal satellite acquisition and inertial navigation real-time calibration as described in any one of claims 1 to 4.

6. An electronic system, characterized in that, Includes the satellite terminal equipment described in claim 5.

7. A readable storage medium, characterized in that, A computer program is stored in a readable storage medium, which is loaded by a processor and executed as described in any one of claims 1 to 4, for low-Earth orbit phased array terminal satellite acquisition and inertial navigation real-time calibration.

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