Satellite tracking method and device based on satellite signal fusion

Abstract

The invention relates to the technical field of satellite communication, and discloses a satellite tracking method and device based on satellite signal fusion, and the device comprises a multi-source information collection unit, a central processing unit, and a phased array antenna unit. The central processing unit judges and obtains a mode signal representing the current working mode according to the obtained signal to noise ratio of the signal and the triaxial angular velocity vector; selecting one of preset control logics according to the mode signal, and adaptively weighting or selecting a signal feedback correction vector, a predictive attitude compensation vector, a real-time attitude compensation vector and the like so as to calculate a beam pointing adjustment vector; and finally, generating a final beam pointing vector to drive the phased-array antenna unit. Through the dynamic switching control strategy, the problem that different working conditions are difficult to consider in a traditional method is solved, the tracking precision, the dynamic response speed and the signal recapturing capability of the system in a complex environment are remarkably improved, and the overall stability and robustness are enhanced.

Description

Technical Field

[0001] This invention relates to the field of satellite communication technology, specifically to a satellite tracking method and apparatus based on satellite signal fusion. Background Technology

[0002] With the rapid development of satellite communication technology, especially the deployment and application of low-Earth orbit and medium-Earth orbit satellite systems, mobile terminals such as vehicle-mounted, ship-mounted, or airborne terminals are placing higher demands on the continuous and stable tracking of satellites. Phased array antennas, as a beamforming technology without mechanical inertia, have become the mainstream choice for mobile satellite communication terminals. However, in practical application environments, traditional satellite tracking systems face multiple challenges, making it difficult for them to provide highly reliable communication services.

[0003] Existing satellite tracking systems typically rely on a single or fixed-weighted control strategy, and their main problem is that they are difficult to adapt to the highly dynamic motion of the terminal and the rapid changes in the signal environment at the same time.

[0004] On the one hand, traditional closed-loop tracking relies primarily on satellite signal feedback (such as signal-to-noise ratio or signal gradient) to achieve precise beam alignment. This feedback-based strategy provides high tracking accuracy under conditions of high signal-to-noise ratio and stable terminal attitude, but it is essentially a lag control. When the terminal is in high-dynamic scenarios such as severe ship rolling or high-speed vehicle turning, beam pointing adjustments always lag behind changes in the terminal's attitude. Furthermore, the inherent delay of the system control loop further amplifies this lag effect, leading to significant beam pointing deviations and even target loss, severely impacting communication continuity. While introducing inertial measurement unit (IMU) data for attitude compensation can improve this problem, simple real-time attitude compensation remains an immediate correction and cannot provide forward-looking compensation capabilities.

[0005] On the other hand, satellite communication is easily affected by factors such as terrain, buildings, or rain attenuation, leading to a rapid decline in signal quality or even instantaneous interruption. In cases of extremely poor signal quality or complete loss of lock, control strategies relying on signal feedback will fail. At this point, existing systems can typically only rely on ephemeris information and IMU data for simple blind tracking, lacking the ability to predict future motion trends and a systematic active search mechanism, resulting in low signal reacquisition efficiency, long processing times, and prolonged communication interruptions.

[0006] Therefore, existing technologies generally suffer from the drawbacks of difficulty in simultaneously achieving tracking accuracy and dynamic response speed, as well as insufficient robustness when signal lock is lost. There is an urgent need for a satellite tracking system capable of dynamically determining its operating status based on the terminal's real-time attitude and signal quality, and adaptively switching multi-source information fusion control strategies to ensure stable and highly reliable satellite tracking under various complex operating conditions. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a satellite tracking method and apparatus based on satellite signal fusion, which solves the problems that existing satellite tracking systems, due to their use of fixed or single control strategies, struggle to meet the requirements of high dynamic response and high-precision tracking, and lack a fast and robust reacquisition mechanism when signal lock is lost.

[0008] To address the aforementioned technical problems, the first aspect of this invention provides a satellite tracking device based on satellite signal fusion. The device includes: The multi-source information acquisition unit is used to acquire the signal-to-noise ratio, three-axis angular velocity vector, and theoretical pointing vector; The central processing unit is used to determine the mode signal that represents the current working mode based on the signal-to-noise ratio and the three-axis angular velocity vector. Based on the mode signal, one of the preset control logics is selected to process at least one compensation or correction vector, thereby calculating the beam pointing adjustment vector. The theoretical pointing vector and the beam pointing adjustment vector are combined to generate the final beam pointing vector. A phased array antenna element is used to adjust the physical pointing of the antenna beam according to the final beam pointing vector.

[0009] In one embodiment of the present invention, the central processing unit further includes an attitude prediction module. This module is designed to handle the terminal's motion in highly dynamic environments by compensating for the inherent delay of the system control loop through feedforward compensation. The attitude prediction module establishes a state-space model of the terminal's attitude motion based on a prediction algorithm, such as a Kalman filter algorithm. This state-space model can be defined by the following state transition equations and observation equations: ; ; Wherein, the state vector Includes the terminal in the current control cycle Three-axis attitude angles and three-axis angular velocities; This is the state transition matrix; It is a control input vector based on accelerometer data; This is an observation vector based on gyroscope data; The observation matrix; and These are process noise and measurement noise, respectively. Using this model, the attitude prediction module performs optimal estimation and short-term prediction of the terminal's attitude, thereby generating a predictive attitude compensation vector.

[0010] In the technical solution of this invention, a core technical concept lies in the fact that the central processing unit can dynamically adjust its control strategy according to real-time changing external conditions. Specifically, the state judgment module in the central processing unit compares the input signal-to-noise ratio and the attitude stability index calculated based on the three-axis angular velocity vector with preset high signal quality thresholds, low signal quality thresholds, and attitude stability thresholds. The attitude stability index can be defined within a preset time window. variance of the interior angular velocity vector The calculation method is as follows: ; in, The average angular velocity within the time window. Through the above comparison, the state determination module can determine the current operating mode from the stable locking mode, high dynamic compensation mode, and signal loss recapture mode, and output the corresponding mode signal.

[0011] The multi-mode fusion control module in the central processing unit executes matching control logic based on the received mode signal: When the mode signal is in stable locked mode, the multi-mode fusion control module adopts a precision-priority strategy. In this case, the beam pointing adjustment vector is mainly formed by weighted fusion of the signal feedback correction vector and the real-time attitude compensation vector, with priority given to the weight of the signal feedback correction vector, so as to achieve fine beam alignment by utilizing high-quality signal feedback.

[0012] When the mode signal is in high dynamic compensation mode, the multi-mode fusion control module adopts a response speed priority strategy. At this time, the beam pointing adjustment vector is mainly formed by weighted fusion of the aforementioned predictive attitude compensation vector and signal feedback correction vector, with priority given to the weight of the predictive attitude compensation vector to achieve feedforward compensation for changes in terminal attitude and ensure timely tracking.

[0013] When the mode signal is in the signal loss and reacquisition mode, the multi-mode fusion control module adopts a blind tracking and active search strategy. In this case, the beam pointing adjustment vector is set to the real-time attitude compensation vector to stabilize the beam, and a search initiation signal is generated. Upon receiving this signal, the beam pointing synthesis module, during the synthesis of the final beam pointing vector, further superimposes a preset scanning trajectory to actively search around the theoretical position of the target satellite, thereby improving the reacquisition probability.

[0014] A second aspect of the present invention provides a satellite tracking method based on satellite signal fusion, the method comprising the following steps: The signal-to-noise ratio, three-axis angular velocity vector, and theoretical pointing vector are obtained through a multi-source information acquisition unit. The central processing unit determines the mode signal representing the current working mode based on the signal-to-noise ratio and the three-axis angular velocity vector. Based on the mode signal, one of at least two preset control logics is selected to process at least one compensation or correction vector, thereby calculating the beam pointing adjustment vector; The theoretical pointing vector is combined with the beam pointing adjustment vector to generate the final beam pointing vector. The physical pointing of the antenna beam is adjusted using phased array antenna elements based on the final beam pointing vector.

[0015] This invention provides a satellite tracking method and apparatus based on satellite signal fusion. It has the following beneficial effects: 1. This invention, by setting up a state judgment module, can accurately identify whether the system is in a stable locking mode with good signal and stable attitude based on the signal-to-noise ratio and terminal attitude stability indicators. In this mode, the multi-mode fusion control module will prioritize a control strategy based on the signal feedback correction vector. This strategy can fully utilize high-quality signal feedback information to finely adjust the beam pointing, suppressing various minor disturbances to the maximum extent, thereby achieving a tracking effect with higher accuracy and stability than traditional single control strategies.

[0016] 2. For scenarios involving violent terminal movements, this invention can switch to a high-dynamic compensation mode via the state judgment module. In this mode, the core of the system control logic focuses on the predictive attitude compensation vector output by the attitude prediction module. This vector, based on the Kalman filter algorithm, predicts the terminal's future attitude in advance. Its feedforward compensation effectively offsets the inherent delay of the control loop, ensuring that even under high-speed maneuvers or severe vibrations, the antenna beam can promptly and accurately compensate for changes in the terminal's attitude, maintaining a stable lock on the satellite.

[0017] 3. When the signal is lost due to obstruction or other reasons, this invention can enter a signal lock-off reacquisition mode. In this mode, the system uses real-time attitude compensation vectors for blind tracking to ensure that the antenna beam can continue to be aligned with the satellite's theoretical position based on inertial sensor data even without signal feedback. Simultaneously, it performs an active and systematic airspace search by superimposing a preset scanning trajectory on top of the blind tracking. This greatly increases the probability of reacquiring the satellite signal, shortens the interruption time, and significantly enhances the reliability and robustness of the entire tracking system. Attached Figure Description

[0018] Figure 1 This is a block diagram of the overall structure of the satellite tracking system of the present invention; Figure 2This is a block diagram of the internal structure of the satellite signal acquisition module of the present invention; Figure 3 This is a flowchart of the satellite tracking method of the present invention; Figure 4 This is a block diagram of the internal functional modules of the central processing unit of the present invention; Figure 5 This is a schematic diagram of the working state determination logic of the present invention; Figure 6 This is a flowchart illustrating the multi-mode fusion control strategy logic of the present invention. Figure 7 This is a block diagram of the internal structure of the control array antenna unit of the present invention. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] See attached document Figure 1 The present invention provides a satellite tracking system, which includes: a multi-source information acquisition unit 10, a central processing unit 20, and a phased array antenna unit 30.

[0021] A multi-source information acquisition unit 10 is used to acquire raw data related to satellite tracking from multiple information sources. A central processing unit 20, whose input is connected to the output of the multi-source information acquisition unit 10, is used to receive and process the raw data, and generate a final beam pointing vector according to a preset algorithm logic. A phased array antenna unit 30, whose control input is connected to the output of the central processing unit 20, is used to receive the final beam pointing vector and adjust the physical pointing of the antenna beam accordingly.

[0022] In one embodiment, the multi-source information acquisition unit 10 includes: a satellite signal acquisition module 11, a terminal attitude perception module 12, and a satellite ephemeris information module 13.

[0023] The satellite signal acquisition module 11 is used to receive satellite downlink signals via a radio frequency front-end, demodulate the signals through an internal baseband processor, and calculate and output one or more parameters characterizing signal quality. In a specific implementation, this parameter is the signal-to-noise ratio, denoted as . .

[0024] The terminal attitude sensing module 12 is physically configured as one or more inertial measurement units (IMUs), each including a three-axis gyroscope and a three-axis accelerometer. The terminal attitude sensing module 12 is used to measure the attitude dynamics data of the terminal body in real time and outputs a three-axis angular velocity vector. and triaxial acceleration vector .

[0025] The satellite ephemeris information module 13 includes a memory for storing satellite ephemeris data and a Global Positioning System (GPS) receiver for obtaining the terminal's own geographical location. The satellite ephemeris information module 13 is used to parse the ephemeris data based on the current time and the terminal's own location, calculate and output the theoretical pointing vector of the satellite at the current time. .

[0026] In one embodiment, the central processing unit 20 may be physically implemented as a digital signal processor (DSP), a field-programmable gate array (FPGA), or a general-purpose processor, and internally contains or runs program instructions for implementing the method of the present invention. The central processing unit 20 includes: a state determination module 21, an attitude prediction module 22, a multi-mode fusion control module 23, and a beam pointing synthesis module 24.

[0027] The status determination module 21 has its input terminals connected to the satellite signal acquisition module 11 and the terminal attitude perception module 12, respectively. The signal-to-noise ratio of the received signal in this module is... and angular velocity vector This module calculates the time window using the following formula. variance of the interior angular velocity vector

[0028] ; in, For the current control cycle, For the index of sampling points within the time window, The average angular velocity within the time window. It is a difference vector. Let represent the square of the Euclidean norm of the difference vector. It is the sum of the squared deviation values ​​of all sampling times within the time window.

[0029] The state determination module 21 will calculate the... and input The signal is compared with a preset threshold and outputs a mode signal that represents the current system operating mode. .

[0030] The attitude prediction module 22 has its input connected to the terminal attitude sensing module 12. Based on the Kalman filter algorithm, the attitude prediction module 22 performs optimal estimation and short-term prediction of the terminal's attitude by establishing a state-space model of the terminal's attitude motion. This state-space model includes state transition equations and observation equations: ; ; Wherein, the state vector Includes the terminal in the current control cycle Three-axis attitude angles and three-axis angular velocities; This is the state transition matrix; To control the input matrix; It is a control input vector based on accelerometer data; This is an observation vector based on gyroscope data; The observation matrix; and These are process noise and measurement noise, respectively. This represents the internal evolution of the system's state; This represents the influence of external inputs. The output of the attitude prediction module 22 is a predictive attitude compensation vector. This vector represents the amount of feedforward beam adjustment required to offset the expected attitude change of the terminal in the next control cycle.

[0031] The multi-mode fusion control module 23 has its input terminals connected to the state determination module 21, the attitude prediction module 22, and the satellite signal acquisition module 11, respectively. The multi-mode fusion control module 23 receives mode signals. Predictive attitude compensation vector and the signal feedback correction vector derived from the signal quality parameters. and the real-time attitude compensation vector derived from real-time attitude data The multi-mode fusion control module 23 controls the input mode signal. It selects one from multiple preset control logics, performs weighted fusion on the input compensation or correction vectors, calculates and outputs a comprehensive beam pointing adjustment vector. .

[0032] The beam pointing and combining module 24 has its inputs connected to the satellite ephemeris information module 13 and the multi-mode fusion control module 23, respectively. The beam pointing and combining module 24 receives the theoretical pointing vector. and beam pointing adjustment vector The beam pointing synthesis module 24 performs vector synthesis using the following formula to generate the final beam pointing vector.

[0033] ; The final beam pointing vector The signal is output to the phased array antenna element 30. The phased array antenna element 30, as the system's execution unit, internally includes a beamforming network controller and an antenna phase shifter array. The controller of the phased array antenna element 30 receives the final beam pointing vector from the central processing unit 20. The required phase delay value for each phase shifter in the array is calculated, and these phase shifters are configured so that the main lobe of the synthetic beam radiated by the antenna array points in the same direction as the phase shifter. The directions indicated are consistent.

[0034] See attached document Figure 2 In one specific embodiment, the satellite signal acquisition module 11 has its radio frequency input terminal connected to the phased array antenna element 30, and its data output terminal connected to the central processing unit 20. This module is used to convert the high-frequency radio frequency signal received by the antenna into a quantized signal quality parameter, such as the signal-to-noise ratio. .

[0035] The satellite signal acquisition module 11 includes: a radio frequency front-end 111 for amplifying, down-converting, and filtering the received signal; an analog-to-digital converter 112 for converting the processed analog signal into a digital signal sequence; and a baseband processor 113, which may be physically implemented as a digital signal processor (DSP), for processing the digital signal sequence to estimate the signal-to-noise ratio of the signal. .

[0036] First, a synchronization operation is performed, including timing synchronization and carrier synchronization, to recover the symbol and phase information of the baseband signal from the digital signal sequence. Second, based on the synchronized signal, the signal power and noise power are estimated respectively. In a specific implementation, the signal power... The estimate is obtained by calculating the average of the squared magnitudes of the received signal constellation point vectors. Noise power The estimate is obtained by calculating the variance of the error vector between the received signal constellation point and its nearest ideal constellation point. Finally, based on the estimated signal power... and noise power The signal-to-noise ratio is calculated using the following formula. (Unit: dB): ; The baseband processor 113 calculates the signal-to-noise ratio. As the final output of the module, it is sent to the central processing unit 20.

[0037] In one specific embodiment, the terminal attitude sensing module 12 is used to measure the attitude angular velocity and linear acceleration of the terminal body, providing dynamic data for subsequent state judgment and motion prediction.

[0038] The terminal attitude sensing module 12 includes an inertial measurement unit 121 and a data processing circuit 122. The inertial measurement unit 121 integrates a three-axis gyroscope and a three-axis accelerometer to output raw data of angular velocity and linear acceleration. The data processing circuit 122 performs deviation compensation and digital filtering on the raw data to output processed three-axis angular velocity vectors and three-axis acceleration vectors.

[0039] In one specific implementation, the data processing circuit 122 performs the following steps: First, it performs bias compensation. The circuit reads the gyroscope bias vector, pre-calibrated or measured during system initialization, from internal non-volatile memory. and accelerometer deviation vector Then, by subtracting the corresponding deviation vector from the original data using the following formula, the compensated data is obtained: ; ; in, and They are respectively Raw data of angular velocity and acceleration at time t. and This is the data after deviation compensation.

[0040] Secondly, digital filtering is performed. To eliminate high-frequency random noise contained in the compensated data, the data processing circuit 122 performs digital filtering. and A digital low-pass filter is applied. In one embodiment, the filter is a finite impulse response (FIR) filter or an infinite impulse response (IIR) filter, whose cutoff frequency is set above the expected maximum motion frequency of the terminal body but below the dominant noise frequency.

[0041] After deviation compensation and digital filtering, the data processing circuit 122 outputs the final three-axis angular velocity vector. and triaxial acceleration vector These vectors are sent to the central processing unit 20 via a serial peripheral interface (SPI) or an internal integrated circuit (I2C) bus.

[0042] In one specific embodiment, the multi-source information acquisition unit 10 includes a satellite ephemeris information module 13, whose data output terminal is connected to the beam pointing synthesis module 24 in the central processing unit 20. This module is used to calculate the theoretical pointing vector of the satellite relative to the terminal at the current moment based on the terminal's real-time position and the satellite's orbital parameters. This provides a benchmark for beam pointing synthesis.

[0043] The satellite ephemeris information module 13 includes: a Global Positioning System (GPS) receiver 131 for acquiring the terminal's precise geographic coordinates and Coordinated Universal Time (UTC); an ephemeris memory 132 for storing the target communication satellite's orbital parameter data; and a pointing vector calculation circuit 133. This pointing vector calculation circuit 133 receives data from the GPS receiver 131 and the ephemeris memory 132, performs a series of coordinate system calculations, determines and outputs the satellite's theoretical pointing vector. .

[0044] In a specific implementation, the circuit performs the following steps: First, the circuit acquires the terminal's real-time geographic coordinates and UTC time from the GPS receiver 131, and reads the ephemeris data of the target satellite from the ephemeris memory 132. Second, the circuit applies an orbital propagation model, such as the Simplified General Perturbation Model SGP4 suitable for low Earth orbit satellites, to calculate the satellite's position vector in a geocentric inertial (ECI) coordinate system based on the read ephemeris data and the current UTC time. Furthermore, the circuit converts the terminal's geographic coordinates obtained from the GPS receiver 131 into a terminal position vector in the same geocentric inertial coordinate system. Then, the circuit calculates the line-of-sight vector from the terminal to the satellite using the following formula.

[0045] ; Finally, the circuit defines the line-of-sight vector in the geocentric inertial coordinate system. Perform a coordinate system transformation to convert the vector to a local horizontal coordinate system with the terminal as the origin (e.g., zenith-azimuth-altitude coordinate system or northeast-northeast coordinate system). The vector obtained after the coordinate system transformation is the final output satellite theoretical pointing vector. The vector is sent to the central processing unit 20.

[0046] See attached document Figure 4 - Appendix Figure 6The central processing unit 20 includes a state determination module 21. This module is connected to the satellite signal acquisition module 11 and the terminal attitude perception module 12. It is used to determine the current working state of the system based on the received signal quality and terminal attitude stability data by comparing them with a preset threshold, and output a corresponding mode signal to the multi-mode fusion control module 23.

[0047] In a specific implementation, the state determination module 21 performs this function in each control cycle. Receives two input data streams: the signal-to-noise ratio output by the satellite signal acquisition module 11. and the three-axis angular velocity vector output by the terminal attitude sensing module 12. .

[0048] The state determination module 21 first determines the state based on the received angular velocity vector. The attitude stability index, which characterizes the degree of drastic change in the terminal's attitude, is calculated. In one embodiment, this index is the attitude stability index over the past... The variance of the angular velocity vector within a time window of each control cycle The calculation formula is as follows: ; in, For the index of sampling points within the time window, The Euclidean norm of the orientation quantity is represented by... It is the arithmetic mean of the angular velocity vectors within this time window.

[0049] Subsequently, the status determination module 21 reads three preset thresholds from its internal memory: a high signal quality threshold. Low signal quality threshold and attitude stability threshold This module will accept the input. and calculated The current operating mode is determined by logically comparing the data with these thresholds. The judgment logic is as follows: like and If so, the system is determined to have entered stable locking mode (Mode A).

[0050] like and If so, the system is determined to have entered the high dynamic compensation mode (ModeB).

[0051] like If the signal is lost and recaptured, the system is determined to have entered the signal loss recapture mode (Mode C).

[0052] Based on the results of the above logical judgment, the state judgment module 21 generates a pattern signal. This signal is a numeric code or enumeration value used to uniquely identify the current operating mode (ModeA, ModeB, or ModeC). This mode signal It is output to the multi-mode fusion control module 23, serving as the direct basis for its selection of subsequent control strategies.

[0053] In one specific embodiment, the central processing unit 20 includes an attitude prediction module 22. The input of this module is connected to the output of the terminal attitude perception module 12 in the multi-source information acquisition unit 10. The output of this module is connected to the multi-mode fusion control module 23 in the central processing unit 20.

[0054] The attitude prediction module 22 is used to establish a mathematical model of the terminal's attitude motion and predict the attitude of the next control cycle based on the model to generate a compensation vector with feedforward properties to compensate for the inherent delay of the system control loop. In one embodiment, this module implements this function by executing a Kalman filter algorithm.

[0055] The attitude prediction module 22 first defines the terminal's attitude motion as a state-space model. At discrete time intervals... The system's state vector Defined as the three-axis attitude angles including the terminal. and triaxial angular velocity The combined vector. The linear state transition equation and observation equation of the model are as follows: ; ; in, This is the state transition matrix, which is constructed based on the principles of attitude kinematics and describes how the attitude angle is obtained by integrating the angular velocity. To control the input matrix; The acceleration vector output by the terminal attitude sensing module 12 The control input constitutes the configuration; The observation vector is directly taken from the angular velocity vector output by the terminal attitude sensing module 12. The observation matrix is ​​used to analyze the state vector. Extract the components corresponding to the observation vector; and The process noise and measurement noise are respectively, and their covariance matrices are respectively and .

[0056] Subsequently, the attitude prediction module 22 performs a recursive Kalman filter calculation, which includes a prediction step and an update step. In the prediction step, the attitude prediction module 22 calculates a prior estimate of the state. and its error covariance matrix In the update step, attitude prediction module 22 calculates the Kalman gain. And combined with the current observation vector The prior estimate is corrected to obtain the optimal posterior estimate. and its error covariance matrix .

[0057] After obtaining the posterior optimal estimate Then, the attitude prediction module 22 uses the state transition equation to perform a recursive calculation to determine the next control cycle. State prediction value The attitude prediction module 22 calculates a predictive attitude compensation vector based on the predicted state value. This vector This represents the amount of reverse adjustment required to the antenna beam to completely counteract the anticipated attitude change of the terminal from the current moment to the end of the next control cycle. This vector... It is output to the multi-mode fusion control module 23.

[0058] The multi-mode fusion control module 23 has the core function of determining the mode signal input by the state judgment module 21. The multi-mode fusion control module 23 dynamically selects a preset control strategy. It receives and fuses adjustment information from three sources: the predictive attitude compensation vector output by the attitude prediction module 22. Real-time attitude compensation vector derived from real-time attitude data And the signal feedback correction vector derived based on signal quality parameters. By executing the selected control strategy (e.g., weighting or selecting the input vectors mentioned above), the multi-mode fusion control module 23 calculates and outputs a comprehensive beam pointing adjustment vector. To beam pointing synthesis module 24.

[0059] The multi-mode fusion control module 23 controls the mode signals received. The value determines which of the following three mutually exclusive control logics will be executed: When mode signal In the stable locked mode (Mode A), the multi-mode fusion control module 23 employs a precision-priority strategy. It calculates the beam pointing adjustment vector using the following formula.

[0060] ; in, and These are the preset weighting coefficients for this mode. For weighted signal feedback correction components, For the weighted attitude compensation component, and The value is much greater than The value is used to ensure that the beam pointing is finely adjusted primarily by signal feedback.

[0061] When mode signal In High Dynamic Compensation Mode (ModeB), the multi-mode fusion control module 23 employs a response speed priority strategy. It calculates the beam pointing adjustment vector using the following formula. : ; in, and These are the preset weighting coefficients for this mode. This is the weighted predictive compensation component. This is the weighted signal feedback correction component, and The value is much greater than The value is set to ensure that the beam pointing is primarily feedforward compensated by the predictive attitude compensation vector.

[0062] When mode signal In the signal loss-of-lock reacquisition mode (ModeC), the multi-mode fusion control module 23 employs a blind tracking and active search strategy. In this mode, the module directs the beam towards the adjustment vector. Directly set as the real-time attitude compensation vector ,Right now Simultaneously, the module generates a search start signal, which drives the beam pointing synthesis module 24 to superimpose a preset spiral or grid scanning trajectory on top of blind tracking.

[0063] Finally, the multi-mode fusion control module 23 will adjust the beam pointing vector calculated based on the current mode. Output to beam pointing synthesis module 24.

[0064] In one specific embodiment, the central processing unit 20 includes a beam pointing synthesis module 24. This module receives the theoretical pointing vector output by the satellite ephemeris information module 13. and the beam pointing adjustment vector output by the multi-mode fusion control module 23. The beam pointing synthesis module 24 synthesizes the two vectors represented in the same local coordinate system to generate a final beam pointing vector, and outputs it as a command to the phased array antenna element 30.

[0065] In both the stable locking mode (ModeA) and the high dynamic compensation mode (ModeB), the beam pointing synthesis module 24 performs standard vector addition. The final beam pointing vector is calculated using the following formula.

[0066] ; This operation combines macroscopic pointing based on satellite ephemeris with microscopic adjustments based on real-time sensor data and signal feedback to form a precise pointing command.

[0067] In signal loss-of-lock reacquisition mode (ModeC), the execution logic of beam pointing synthesis module 24 is extended. Besides receiving... and In addition, the beam pointing and combining module 24 also receives a search start signal from the multi-mode fusion control module 23. When this signal is valid, the beam pointing and combining module 24 performs the following steps: First, calculate a reference pointing vector for stable tracking. Its calculation method is the same as the aforementioned model, that is: ; In this mode Equal to real-time attitude compensation vector .

[0068] Secondly, the beam pointing synthesis module 24 reads a preset scan trajectory template from its internal memory and generates a time-varying scan offset vector. In one embodiment, the scan trajectory is a spiral whose angular components (e.g., azimuth and pitch) in the terminal's local coordinate system expand over time to achieve airspace coverage from the center outwards.

[0069] Finally, the beam pointing synthesis module 24 synthesizes the reference pointing vector and the scan offset vector to obtain the final beam pointing vector in this mode: ; This operation allows the antenna beam to be stably aligned with the satellite's theoretical position while simultaneously performing a small-scale, systematic scan around that position to increase the probability of reacquiring the signal.

[0070] Regardless of the mode, the calculated final beam pointing vector It is represented as a set of angular coordinates (e.g., azimuth and elevation angles) in the terminal's local coordinate system. This set of coordinates is formatted as digital instructions and sent to the phased array antenna element 30 via the internal data bus.

[0071] See attached document Figure 7In one specific embodiment, the satellite tracking system includes a phased array antenna element 30. This element, serving as the system's execution component, has its control input connected to the beam pointing and combining module 24 of the central processing unit 20. The phased array antenna element 30 includes a beamforming network controller 31, a phase shifter array 32, and an antenna array 33. Its overall function is to combine the received final beam pointing vector... It is converted into a high-gain radio frequency beam with the same physical direction.

[0072] During this process, the beamforming network controller 31 is responsible for receiving the angular coordinates representing the target's direction. Based on this, a set of phase control values ​​for each phase shifter in the phase shifter array 32 is calculated. The phase shifter array 32 performs independent phase modulation on each signal fed into the antenna array 33 according to the set of phase control values, thereby enabling the antenna array 33 to synthesize a beam pointing in a predetermined direction in space.

[0073] In one specific implementation, the beamforming network controller 31 internally stores the precise physical location coordinates of each antenna element in the antenna array 33. For each antenna element in the antenna array 33 located at the... line, number The antenna elements of the array, their positions in a two-dimensional coordinate system with the array center as the origin are: The controller determines the direction based on the received pointing angle. and the wavelength of the signal The phase delay value that the phase shifter corresponding to the antenna element needs to be set can be calculated using the following formula.

[0074] ; in, This is due to the displacement of the antenna element in the X-axis direction. The introduced path difference, This is due to the displacement of the antenna element in the Y-axis direction. The introduced path difference is used by the controller to perform the above calculation once for each antenna element in the antenna array 33, thereby generating a complete set of phase control words.

[0075] The phase shifter array 32 has phase shifters that correspond one-to-one with and are connected to the antenna radiating elements of the antenna array 33. The phase shifter array 32 receives the phase control word generated by the beamforming network controller 31 and applies an independent phase delay to the signal fed into each radiating element in the antenna array 33.

[0076] The phase-modulated electromagnetic waves emitted by each radiating element in the antenna array 33 interfere in the far-field space, thereby forming a high-gain main beam in the direction determined by the set of phase control words, and converting the calculation results of the central processing unit 20 into the precise pointing of the physical beam.

[0077] See attached document Figure 3 This invention provides a satellite tracking method, which consists of a continuously running closed-loop control process. Within one control cycle, the method specifically includes the following steps: Step S301: Perform multi-source information acquisition. This step is performed by the multi-source information acquisition unit 10. In one embodiment, this step executes three sub-steps in parallel: First, the satellite signal acquisition module 11 receives and processes the satellite downlink signal, demodulates it, and calculates the current signal-to-noise ratio. .

[0078] Secondly, the terminal attitude sensing module 12 measures and outputs the real-time three-axis angular velocity vector of the terminal body. and triaxial acceleration vector .

[0079] Third, by using the satellite ephemeris information module 13, combined with the terminal's own position and current time, the ephemeris data is analyzed to calculate the satellite's theoretical pointing vector. .

[0080] Step S302: Perform dynamic judgment of working status. This step is performed by the status judgment module 21 in the central processing unit 20. This module receives the status obtained in step S301. and This module first, based on Calculate the attitude stability index Then and With preset signal quality threshold , and attitude stability threshold The system compares data, determines its current operating mode based on preset logic, and outputs a mode signal. The signal It is characterized as one of the following modes: stable locking mode, high dynamic compensation mode, or signal loss and recapture mode.

[0081] Step S303: Perform terminal motion attitude prediction. This step is performed by the attitude prediction module 22 in the central processing unit 20. This module receives the attitude prediction data obtained in step S301. and This module uses these data as observations and control inputs, feeds them into a pre-defined state-space model based on Kalman filtering, performs one prediction step and one update step, and obtains the current time step. Optimal attitude estimation Subsequently, the module utilizes the state transition equation to... Perform a recursive calculation to determine the next control cycle. State prediction value Based on this, a predictive attitude compensation vector is generated. .

[0082] Step S304: Execute the multi-mode fusion control strategy. This step is executed by the multi-mode fusion control module 23 in the central processing unit 20. This module receives the mode signal output in step S302. The predictive pose compensation vector output in step S303 At the same time, this module also receives data based on... Calculated signal feedback correction vector and based on based on Calculated real-time attitude compensation vector This module is based on The value is selected from three preset control logics to determine the input. , and Perform weighted or selected calculations and output a beam pointing adjustment vector. .

[0083] Step S305: Perform beam pointing vector synthesis. This step is performed by the beam pointing synthesis module 24 in the central processing unit 20. This module receives the theoretical pointing vector output from step S301. and the beam pointing adjustment vector output in step S304 This module performs vector addition operations. (or superimpose a scan vector in a specific mode) ), generating the final beam pointing vector .

[0084] Step S306: Perform beam pointing. This step is performed by the phased array antenna element 30. The beamforming network controller 31 of this element receives the final beam pointing vector output from step S305. The controller calculates a set of phase control words based on the vector and configures the phase shifter array 32 using these phase control words. The phase shifter array 32 modulates the phase of the signal fed into the antenna array 33, causing the antenna array 33 to form a pointing direction in physical space. Consistent beam main lobe.

[0085] Step S307: Iterative Loop. After completing step S306, the method returns to step S301 to enter the next control cycle, starting a new round of information acquisition, processing, and execution, thereby achieving continuous, adaptive closed-loop tracking of the satellite target.

Claims

1. A satellite tracking device based on satellite signal fusion, characterized by, The method comprises the following steps: a multi-source information acquisition unit is used to acquire a signal signal-to-noise ratio, a three-axis angular velocity vector and a theoretical pointing vector; a central processing unit is used to determine a mode signal representing a current working mode according to the signal signal-to-noise ratio and the three-axis angular velocity vector; a control logic is selected from a preset control logic according to the mode signal, at least one compensation or correction vector is processed, and a beam pointing adjustment vector is calculated; the theoretical pointing vector and the beam pointing adjustment vector are combined to generate a final beam pointing vector; and a phased array antenna unit is used to adjust the physical pointing of an antenna beam according to the final beam pointing vector.

2. The satellite tracking device based on satellite signal fusion according to claim 1, characterized in that, The multi-source information acquisition unit comprises: a satellite signal acquisition module used to calculate and output the signal signal-to-noise ratio; a terminal attitude sensing module used to measure and output the three-axis angular velocity vector; and a satellite ephemeris information module used to calculate and output the theoretical pointing vector.

3. The satellite tracking device based on satellite signal fusion according to claim 1, characterized in that, The central processing unit comprises: a state determination module used to perform the operation of determining the mode signal; a multi-mode fusion control module used to perform the operation of selecting the control logic and calculating the beam pointing adjustment vector; and a beam pointing synthesis module used to perform the operation of generating the final beam pointing vector.

4. The satellite tracking device based on satellite signal fusion according to claim 3, characterized in that, The central processing unit further comprises: an attitude prediction module used to calculate and output a predictive attitude compensation vector by a prediction algorithm based on the three-axis angular velocity vector; wherein the predictive attitude compensation vector is one of the at least one compensation or correction vector.

5. The satellite tracking device based on satellite signal fusion according to claim 4, characterized in that, The prediction algorithm is a Kalman filter algorithm, which establishes a state space model for terminal attitude motion and performs optimal estimation and short-time prediction on the terminal attitude to generate the predictive attitude compensation vector.

6. The satellite tracking device based on satellite signal fusion according to claim 3, characterized in that, The state determination module compares the signal signal-to-noise ratio and an attitude stability index calculated based on the three-axis angular velocity vector with a preset high signal quality threshold, a low signal quality threshold and an attitude stability threshold, and then determines the current working mode from a stable locking mode, a high dynamic compensation mode and a signal loss locking recapture mode.

7. The satellite tracking device based on satellite signal fusion according to claim 6, characterized in that, The preset control logic comprises: when the mode signal is the stable locking mode, a signal feedback correction vector and a real-time attitude compensation vector are weighted and fused, and the weight of the signal feedback correction vector is given priority, so as to calculate the beam pointing adjustment vector; when the mode signal is the high dynamic compensation mode, a predictive attitude compensation vector and the signal feedback correction vector are weighted and fused, and the weight of the predictive attitude compensation vector is given priority, so as to calculate the beam pointing adjustment vector.

8. The satellite tracking device based on satellite signal fusion according to claim 6, characterized in that, The preset control logic further comprises: when the mode signal is the signal loss locking recapture mode, the beam pointing adjustment vector is set as the real-time attitude compensation vector, and a search start signal is generated; the beam pointing synthesis module is further used to superimpose a preset scanning trajectory in the process of synthesizing the final beam pointing vector when the search start signal is received.

9. The satellite tracking device based on satellite signal fusion according to claim 2, characterized in that, The terminal posture sensing module comprises an inertial measurement unit and a data processing circuit, the data processing circuit being configured to perform bias compensation and digital filtering on raw data output by the inertial measurement unit, thereby outputting the three-axis angular velocity vector.

10. A satellite tracking method based on satellite signal fusion, characterized in that, The method comprises the following steps: Through a multi-source information acquisition unit, a signal signal-to-noise ratio, a three-axis angular velocity vector and a theoretical pointing vector are acquired; Through a central processing unit, a mode signal representing a current working mode is determined according to the signal signal-to-noise ratio and the three-axis angular velocity vector; According to the mode signal, one of at least two preset control logics is selected to process at least one compensation or correction vector, thereby calculating a beam pointing adjustment vector; The theoretical pointing vector and the beam pointing adjustment vector are combined, thereby generating a final beam pointing vector; Through a phased array antenna unit, the physical pointing of an antenna beam is adjusted according to the final beam pointing vector.

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