An unmanned aerial vehicle measurement and control system based on polarization adaptation and multi-link intelligent switching
Patent Information
- Application Number
- CN202611081079.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-07-21
- Publication Date
- 2026-10-23
Smart Images
Figure CN122969645A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of UAV telemetry, control and communication technology, and in particular to a UAV telemetry, control system based on polarization adaptation and multi-link intelligent switching. Background Technology
[0002] The UAV telemetry and control link is used to transmit flight control commands, telemetry data, mission payload data, and safety status data. It is a key communication link to ensure the safe flight and mission execution of UAVs.
[0003] Existing UAV telemetry, tracking, and command (TT&C) systems typically employ antennas with fixed polarization or mechanically adjustable polarization. During flight, UAVs undergo attitude changes such as roll, pitch, and yaw, causing the polarization direction of the airborne antenna to deflect relative to the ground station antenna. When the polarization directions of the two antennas mismatch, polarization mismatch loss occurs, leading to decreased received signal strength, increased bit error rate, and reduced link margin. In severe cases, this can cause the TT&C link to be interrupted.
[0004] Existing technologies also include solutions to improve communication reliability by adjusting antenna direction, increasing antenna gain, or setting up backup links, but the following problems still exist:
[0005] Passive adjustments based solely on the current quality of the received signal cannot predict in advance the polarization mismatch caused by changes in the drone's attitude.
[0006] There is a lack of polarization vector calculation models based on three-dimensional attitude matrices, and polarization compensation is mostly limited to empirical adjustments or simple angle corrections.
[0007] Multi-link handover is mainly based on traditional link metrics such as SNR, BER, and latency, without taking polarization matching degree into link selection.
[0008] Prediction modules are mostly functional descriptions, lacking clear inputs, outputs, network structure, training methods, and control objects, which can easily lead to insufficient disclosure.
[0009] In complex electromagnetic environments, interference avoidance, multi-link switching, and polarization reconfiguration are isolated from each other and cannot form a unified, coordinated control loop.
[0010] Therefore, there is a need for a UAV telemetry, tracking, and communication system and method that can predict polarization change trends in advance based on UAV attitude, position, link quality, and electromagnetic environment conditions, perform polarization reconstruction through digital phased array antennas, and combine polarization matching degree for intelligent multi-link switching. Summary of the Invention
[0011] This invention addresses the technical problems existing in the background art by proposing a UAV telemetry and control system based on polarization adaptation and intelligent multi-link switching. By adjusting the polarization state of the ground station antenna in advance based on attitude prediction, and using the polarization matching degree as a weighting factor in the multi-link comprehensive score to participate in link selection and advance switching decisions, the system achieves stable maintenance and adaptive switching of UAV telemetry and control communication links.
[0012] To solve the technical problem, the technical solution of the present invention is as follows: A UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching includes a ground station module, a UAV airborne module, and a multi-link communication network; The ground station module and the UAV onboard module establish a communication connection through at least two communication links in the multi-link communication network; The ground station module includes a prediction and coordination control unit, a digital phased array polarized reconfigurable antenna array, and a multi-link communication unit. The UAV onboard module is used to collect the UAV's attitude data, positioning data, and link status data, and generate a state vector to send to the prediction and coordination control unit. The prediction and cooperative control unit is used to predict the position and attitude angle of the UAV within a preset time period based on the state vector, construct a prediction rotation matrix based on the predicted attitude angle, and calculate the predicted airborne antenna polarization vector based on the preset initial polarization vector of the airborne antenna. The prediction and coordination control unit is also used to generate a target polarization vector based on the predicted airborne antenna polarization vector, decompose the target polarization vector into horizontal polarization components and vertical polarization components, and calculate the horizontal polarization channel weights and vertical polarization channel weights of each element of the digital phased array polarization reconfigurable antenna array, so as to control the digital phased array polarization reconfigurable antenna array to synthesize a target polarization beam that matches the predicted airborne antenna polarization state. The multi-link communication unit is used to collect link quality data for each communication link; The prediction and coordination control unit is also used to calculate the current comprehensive score and the predicted comprehensive score within a preset time period of each communication link based on the link quality data and polarization matching degree, and to perform link switching when the predicted comprehensive score of the backup link is higher than the predicted comprehensive score of the current working link and exceeds a preset threshold.
[0013] Furthermore, the UAV onboard module includes an IMU attitude sensor, a GPS / BeiDou positioning module, an onboard data fusion module, and an onboard multi-link communication terminal; the onboard data fusion module is used to perform time synchronization and data fusion of attitude data, position data, velocity data, link quality data, and interference intensity data to generate the state vector.
[0014] Furthermore, the digital phased array polarization reconfigurable antenna array includes multiple dual-polarized array elements, each dual-polarized array element including a horizontal polarization channel and a vertical polarization channel, and each channel is configured with an independent amplitude control unit and a phase control unit; the prediction and coordination control unit determines the amplitude ratio and phase difference between the horizontal polarization component and the vertical polarization component according to the target polarization vector, and calculates the horizontal polarization channel weight and vertical polarization channel weight of each array element accordingly.
[0015] Furthermore, the prediction and collaborative control unit uses a time series prediction model to process historical state sequences in order to predict the position and attitude angle of the UAV within a preset time period in the future; the time series prediction model is a Long Short-Term Memory (LSTM) neural network.
[0016] Furthermore, the polarization matching degree is calculated based on the polarization mismatch angle between the UAV airborne antenna polarization vector and the ground station antenna polarization vector, satisfying: PM = |cos(Δα)|² Where Δα is the angle between the polarization vector of the UAV's onboard antenna and the polarization vector of the ground station's antenna, and PM is the polarization matching degree.
[0017] Furthermore, the target polarization vector is determined jointly based on the predicted airborne antenna polarization vector, the antenna installation deviation compensation amount, and the link feedback correction amount.
[0018] Furthermore, the system also includes a polarization closed-loop feedback module; The polarization closed-loop feedback module is used to collect the received signal strength RSSI, signal-to-noise ratio SNR, bit error rate BER, polarization matching degree PM and interference intensity I of the current communication link, and feed them back to the prediction and coordination control unit. The prediction and collaborative control unit performs polarization closed-loop optimization based on an optimization objective function, which satisfies the following:
[0019] in, To optimize the objective function value for polarization, For polarization matching degree, For signal-to-noise ratio, For bit error rate, For interference intensity, , , and These are the weighting coefficients for the corresponding parameters; The prediction and coordination control unit adjusts the amplitude ratio and phase difference between the horizontal polarization component and the vertical polarization component according to the optimization objective function, updates the target polarization vector and recalculates the array element weights until the preset communication quality conditions are met.
[0020] Furthermore, the system also includes an electromagnetic interference detection and avoidance module; the electromagnetic interference detection and avoidance module is used to perform spectrum scanning on the operating frequency band and the backup frequency band, and determine the interference level based on the difference between the interference signal power and the noise floor power; when it is determined to be mild interference, the frequency hopping rate is increased; when it is determined to be moderate interference, the system switches to the backup frequency channel; and when it is determined to be severe interference, the system triggers the communication link switch.
[0021] Furthermore, when the interference signal is detected to have polarization characteristics, the electromagnetic interference detection and avoidance module determines the interference polarization vector; The prediction and cooperative control unit is based on the communication polarization matching degree (PM) and interference coupling degree. The target polarization state is jointly determined, and the target polarization state satisfies:
[0022] in, The optimized target polarization state, For communication polarization matching degree, To interfere with coupling, and These are the weighting coefficients; The interference coupling degree satisfies:
[0023] in, The target communication polarization vector, For the interference polarization vector; The prediction and coordination control unit selects a target polarization state that reduces interference coupling, provided that the polarization matching degree is satisfied by a preset threshold.
[0024] A UAV telemetry and control method based on polarization adaptation and multi-link intelligent switching, applied to the system described in any one of the above, includes: Acquire the drone's attitude data, positioning data, and link status data, and generate a state vector; Predict the position and attitude angle of the UAV within a preset time period based on the state vector; A prediction rotation matrix is constructed based on the predicted attitude angle, and the prediction airborne antenna polarization vector is calculated based on the preset initial polarization vector of the airborne antenna. The target polarization vector is generated based on the predicted airborne antenna polarization vector; The target polarization vector is decomposed into horizontal polarization components and vertical polarization components, and the horizontal polarization channel weights and vertical polarization channel weights of each element of the digital phased array polarization reconfigurable antenna array are calculated based on the horizontal polarization components and vertical polarization components. The digital phased array polarization reconfigurable antenna array is controlled to form a target polarization beam that matches the predicted polarization state of the airborne antenna based on the horizontal polarization channel weights and vertical polarization channel weights. Obtain link quality data and polarization matching degree for each communication link; The current comprehensive score and the predicted comprehensive score within a preset time period are calculated based on the link quality data and polarization matching degree of each communication link. When the predicted comprehensive score of the backup link is higher than the predicted comprehensive score of the current working link and exceeds a preset threshold, link switching is performed.
[0025] This application has the following advantages: First, by using an attitude prediction model based on an LSTM neural network, the roll angle, pitch angle, and yaw angle of the UAV at future moments can be predicted in advance, and the polarization vector of the airborne antenna can be calculated accordingly. This drives the ground station's digital phased array antenna to complete the polarization state reconstruction in advance, realizing an upgrade from passive hysteresis compensation to predictive active alignment, effectively reducing the polarization mismatch loss caused by attitude changes.
[0026] Second, a polarization vector calculation model based on a three-dimensional attitude rotation matrix was established, which accurately maps the UAV attitude angle to the real-time polarization vector of the airborne antenna in the ground coordinate system, and quantifies the polarization alignment degree through polarization matching degree PM, providing a calculable and optimizable quantitative basis for polarization compensation and link decision.
[0027] Third, the polarization matching degree (PM) is incorporated as a key factor with the same weight as the signal-to-noise ratio into the multi-link comprehensive scoring model. This allows link selection to not only be based on traditional communication quality indicators but also to consider the polarization matching state and its future trend, thus enabling predictive link switching in advance and avoiding passive switching after link deterioration.
[0028] Fourth, through polarization closed-loop feedback optimization and electromagnetic interference polarization joint avoidance, a collaborative closed-loop control is formed that generates target polarization, corrects feedback, and minimizes interference coupling. This reduces interference coupling while ensuring communication polarization matching, thereby improving link stability in complex electromagnetic environments. Attached Figure Description
[0029] To more clearly illustrate the technical solutions in the embodiments of this application 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0030] Figure 1 This is a schematic diagram of the overall structure of the UAV telemetry, tracking, and communication system proposed in this application embodiment; Figure 2 This is a schematic diagram of the functional modules of the ground station proposed in the embodiments of this application; Figure 3 This is a schematic diagram of the digital phased array polarization reconfigurable antenna array structure proposed in the embodiments of this application; Figure 4 This is a flowchart of polarization beam generation based on predicted attitude proposed in an embodiment of this application; Figure 5 This is a flowchart of the multi-link intelligent handover process proposed in the embodiments of this application; Figure 6 This is a schematic diagram of the polarization matching principle proposed in the embodiments of this application. Detailed Implementation
[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0032] Example 1: This embodiment provides a UAV telemetry, monitoring, and control method based on polarization adaptation and intelligent multi-link switching. The system addresses issues arising from continuous attitude changes during UAV flight, such as changes in the polarization direction of the airborne antenna, polarization mismatch between the ground station antenna and the airborne antenna, degraded communication link quality, and untimely link switching in complex electromagnetic environments. Through this embodiment, the system can predict the UAV's attitude and position changes within a preset timeframe based on real-time attitude, position, speed, link quality, and electromagnetic environment data, and adjust the polarization state of the ground station's digital phased array antenna in advance, thereby achieving predictive polarization compensation, polarization closed-loop optimization, and adaptive multi-link switching.
[0033] like Figure 1 As shown, the UAV telemetry, tracking, and command (TT&C) communication system in this embodiment includes a ground station module, an UAV onboard module, a multi-link communication network, a prediction and cooperative control module, a polarization closed-loop feedback module, and an electromagnetic interference detection and avoidance module. The ground station module and the UAV onboard module establish a TT&C communication connection through at least two communication links. These communication links may include at least two of the following: dedicated data transmission links, 4G / 5G cellular network links, and satellite communication links. During system operation, the ground station module not only selects communication links based on traditional link quality parameters but also incorporates polarization matching degree and future link quality prediction results into the link decision-making process.
[0034] like Figure 2As shown, the ground station module includes a digital phased array polarized reconfigurable antenna array, a multi-link communication unit, an electromagnetic environment monitoring module, and a prediction and coordination control unit. Figure 3 As shown, the digital phased array polarization reconfigurable antenna array includes multiple dual-polarized elements, each of which includes a horizontal polarization channel H and a vertical polarization channel V. Each element's horizontal and vertical polarization channels are configured with independent amplitude control units and phase control units, respectively. For the nth element, its horizontal polarization channel weights are expressed as:
[0035] Its vertical polarization channel weights are expressed as:
[0036] in, Let n be the amplitude of the horizontal polarization channel of the nth array element. Let n be the phase of the horizontal polarization channel of the nth element. Let be the amplitude of the vertical polarization channel of the nth element. Let be the phase of the vertical polarization channel of the nth element. N represents the number of array elements. By adjusting the amplitude and phase of the horizontal and vertical polarization channels respectively, the ground station antenna array can synthesize linear, circular, or elliptical polarization states, and can reconstruct the target polarization beam in real time according to the UAV's attitude changes.
[0037] The UAV's onboard modules include an onboard dual-polarized antenna or a polarization-adjustable antenna, a multi-link communication terminal, an IMU attitude sensor, a GPS / BeiDou positioning module, a flight control data interface, an electromagnetic interference detection sensor, and an onboard data fusion module. The IMU attitude sensor is used to collect the UAV's three-axis attitude angles, including roll angle. Pitch angle and yaw angle In this embodiment, the sampling frequency of the IMU attitude sensor is preferably 100Hz. The GPS / BeiDou positioning module is used to collect the UAV's position, speed, and heading information, wherein the position data is represented as... Speed data is represented as The sampling frequency of the GPS / BeiDou positioning module can be 10Hz.
[0038] The airborne data fusion module performs time synchronization and data fusion on IMU attitude data, GPS / BeiDou positioning data, flight control mission waypoint data, and airborne electromagnetic interference detection data, and generates the current state vector:
[0039] in, Indicates the current link signal-to-noise ratio. Indicates the current link bit error rate. Indicates the current link latency. This indicates the current electromagnetic interference intensity. The airborne multi-link communication terminal transmits this state vector to the ground station prediction and coordination control unit via the currently available communication link.
[0040] The prediction and cooperative control unit receives state vectors from the UAV's onboard modules, as well as link quality data collected by the ground station's multi-link communication unit and spectral interference data collected by the electromagnetic environment monitoring module. The link quality data includes the signal-to-noise ratio (SNR), received signal strength (RSSI), bit error rate (BER), packet loss rate (PER), end-to-end latency, jitter, link occupancy, polarization matching degree (PM), and interference intensity (I) for each communication link. Based on this data, the prediction and cooperative control unit outputs the predicted attitude, predicted position, target polarization vector, array element amplitude weights, array element phase weights, recommended communication links, recommended frequency channels, and frequency hopping rate control parameters for a preset time period in the future.
[0041] In this embodiment, the system first calculates the real-time polarization vector of the onboard antenna based on the UAV's three-dimensional attitude. Let the initial polarization vector of the onboard antenna in the UAV's body coordinate system be... for:
[0042] in, This indicates that the initial polarization vector is in the body coordinate system. Components along the axial direction; This indicates that the initial polarization vector is in the body coordinate system. Components along the axial direction; This indicates that the initial polarization vector is in the body coordinate system. Components along the axial direction; superscript The expression indicates the transpose of a matrix, signifying that the vector is represented in column vector form.
[0043] When the airborne antenna is initially vertically polarized, the following can be considered:
[0044] The drone's attitude changed from roll angle Pitch angle and yaw angle The roll rotation matrix is:
[0045] The pitch and rotation matrix is:
[0046] The yaw rotation matrix is:
[0047] The overall attitude rotation matrix of the UAV is represented as:
[0048] Indicates the roll angle The resulting roll rotation matrix (around the body) (axis rotation) Indicates the pitch angle The resulting pitch and rotation matrix (around the fuselage) (axis rotation) Indicates the yaw angle The resulting yaw rotation matrix (around the fuselage) (axis rotation) Therefore, the real-time polarization vector of the UAV's onboard antenna in the ground coordinate system is:
[0049] in, This indicates the actual polarization direction that changes with the attitude of the UAV. For example... Figure 6 As shown, let the current synthetic polarization vector of the ground station be... The polarization mismatch angle between the UAV's airborne antenna and the ground station's antenna is... for:
[0050] Furthermore, the polarization matching degree is defined as:
[0051] when When, it indicates that the UAV's onboard antenna and the ground station's antenna are perfectly polarized matched; when When, it indicates that the two are completely orthogonally polarized; when When this occurs, it indicates that the two are in a partially polarization matched state. The corresponding polarization loss... It can be represented as:
[0052] Or it can be expressed as:
[0053] Therefore, the system can obtain the polarization mismatch angle, polarization matching degree, and polarization loss in real time based on the UAV's attitude changes, providing a calculable basis for subsequent polarization compensation and link decision-making.
[0054] To avoid hysteresis compensation based solely on the current attitude, this embodiment further employs a predictive polarization compensation method. Instead of adjusting the ground station antenna polarization state only after the UAV's attitude has changed and communication quality has degraded, the system generates the target polarization state in advance based on attitude predictions within a preset timeframe. Specifically, traditional polarization compensation... It can be represented as:
[0055] The predictive polarization compensation in this embodiment Represented as:
[0056] in, For the prediction time, the preferred value range is 1s to 5s, and in this embodiment, it is further preferred to be 3s.
[0057] The input to the predictive model is a sequence of states over a time window:
[0058] Where M is the time window length. With an IMU sampling frequency of 100Hz and a time window of 5s, M is set to 500. Each frame's state vector... All parameters include the drone's position, speed, attitude angle, link quality, and interference intensity, namely:
[0059] The prediction model outputs the predicted state at future time points. :
[0060] in, For the predicted location at a future time, The predicted attitude angle for future moments.
[0061] In one specific implementation, the prediction model employs an LSTM neural network. This LSTM neural network includes an input layer, a first LSTM layer, a second LSTM layer, a fully connected layer, and an output layer. Specifically, the input layer has an input dimension of 13, the first LSTM layer has 128 hidden units, the second LSTM layer has 64 hidden units, the fully connected layer has 32 nodes, and the output layer has an output dimension of 6. The input size of this network is... The output size is The training data comes from historical flight records of the UAV, including attitude data, position data, velocity data, link quality data, and electromagnetic interference intensity data. Mean squared error is used as the loss function during training.
[0062] in, For the true position and attitude, Here, N represents the predicted position and attitude of the model, and N is the number of training samples. After training, the model is deployed at the ground station prediction and cooperative control unit for online prediction of the UAV's future attitude and position.
[0063] After obtaining the predicted attitude angles for future moments, the system constructs a predicted rotation matrix. :
[0064] And calculate the predicted airborne antenna polarization vector. :
[0065] In one approach, the ground station target polarization vector It can be set directly as:
[0066] In another approach, considering antenna installation deviations and link feedback corrections, the ground station target polarization vector can be corrected as follows:
[0067] in, This is the compensation amount for antenna installation deviation. This refers to the correction amount obtained based on RSSI, SNR, or PM feedback.
[0068] The ground station's digital phased array antenna reconstructs the polarization based on the target polarization vector. Since the ground station antenna uses two orthogonal polarization channels, H (horizontal polarization) and V (vertical polarization), the target polarization vector can be decomposed as follows:
[0069] in:
[0070] Indicates the H / V amplitude ratio angle. This represents the H / V phase difference. When When, linear polarization can be formed; when When the H / V amplitudes are equal, circular polarization can be formed; when the H / V amplitudes are unequal and the phase difference is not zero, elliptical polarization can be formed.
[0071] For the nth array element, its composite weight includes both beam pointing weight and polarization synthesis weight. Let the position vector of the nth array element be... The target beam direction unit vector is The operating wavelength is Then the beam pointing phase is:
[0072] The horizontal polarization channel weights of the nth element are:
[0073] The vertical polarization channel weights of the nth element are:
[0074] in, These are the element amplitude weighting coefficients. The ground station sends the above horizontal polarization channel weights and vertical polarization channel weights to the digital phased array polarization reconfigurable antenna array, enabling the antenna array to synthesize a target polarization beam that matches the predicted airborne polarization state.
[0075] After completing the target polarization beamforming, the system collects feedback metrics from the current communication link, including RSSI, SNR, BER, PM, and interference intensity I. The prediction and coordination control unit performs closed-loop optimization of the polarization state based on the feedback results. Specifically, the polarization optimization objective function is defined as:
[0076] in, Here, is the weighting coefficient, PM is the polarization matching degree, SNR is the signal-to-noise ratio, BER is the bit error rate, and I is the interference intensity. When the objective function fails to reach the preset threshold, or when any of the parameters PM, SNR, or BER fails to meet the requirements, the system adjusts the H / V amplitude ratio and phase difference:
[0077] The element weights are then recalculated and the amplitude and phase control parameters of the digital phased array antenna are updated until a preset condition is met. In this embodiment, the preset condition can be:
[0078] in, The preferred value is 0.85. The preferred value is 10dB. Preferred .
[0079] This embodiment also incorporates polarization matching degree into the multi-link decision-making process. For the i-th communication link, the system defines the comprehensive score as:
[0080] in, For normalized signal-to-noise ratio, Let be the polarization matching degree corresponding to the i-th link. To normalize the bit error rate, For normalized delay, To normalize the interference intensity, This serves as a link availability indicator. to These are weighting coefficients. In a preferred embodiment, , , , , , .
[0081] The system selects the link with the highest overall score as the current working link:
[0082] Here, 'i' can correspond to dedicated data transmission links, 4G / 5G cellular links, and satellite links, respectively. In this way, the system no longer relies solely on traditional communication quality indicators when selecting links, but also considers polarization matching, interference intensity, link availability, and predicted trends.
[0083] When the current link's SNR is below a threshold for a continuous preset time, the current link's BER is above a threshold for a continuous preset time, the current link's delay exceeds a threshold for a continuous preset time, the current link's polarization matching degree (PM) is below a threshold for a continuous preset time, or moderate or severe interference occurs in the frequency band where the current link is located, or when future interference is predicted... If the current link score falls below the backup link score within a few seconds, the system triggers a link handover decision. In this embodiment, the duration for which the SNR is below the threshold can be 5 seconds, the duration for which the BER is above the threshold can be 3 seconds, the duration for which the latency exceeds the threshold can be 2 seconds, and the duration for which the PM is below the threshold can be 3 seconds.
[0084] Furthermore, the prediction and coordination control unit can also predict the overall score of each communication link at future moments:
[0085] When the predicted score of backup link j at a future time is higher than the predicted score of current link k, and the following conditions are met:
[0086] If the connection continues for more than a preset time, the system will switch the communication link from the current link k to the backup link j in advance. Therefore, the link switching implemented in this embodiment is not performed only after the main link has deteriorated significantly, but is performed in advance based on UAV attitude prediction, polarization matching trend, and link quality trend.
[0087] This embodiment also includes an electromagnetic interference detection and collaborative avoidance process. The ground station electromagnetic environment monitoring module includes a spectrum scanning unit and an interference classification unit. The spectrum scanning unit scans the operating frequency band and the spare frequency band according to a preset cycle. The scanning bandwidth can be from 10MHz to 100MHz, and the scanning cycle can be from 1s to 10s. The interference classification unit classifies the interference level according to the increase in interference signal power relative to the noise floor. Specifically, the interference intensity is expressed as:
[0088] Or it can be expressed as:
[0089] in, or This indicates the detected interference power or signal power within the operating frequency band. Indicates the noise floor power. When When the system detects a slight interference, it determines it as a minor disturbance. When the system determines the interference to be moderate, when At that time, the system determined it to be severe interference.
[0090] When the system detects mild interference, it can increase the frequency hopping rate, for example, from 2 hops / s to 10 hops / s, while maintaining the current communication link. When the system detects moderate interference, it can switch to a backup frequency channel and recalculate the overall score of each communication link. When the system detects severe interference, it directly triggers multi-link switching, prioritizing the backup link with the lowest current interference intensity and the highest link score.
[0091] After detecting interference, the system can also perform joint interference and polarization control. Specifically, when the interference signal has obvious polarization characteristics, the system selects a receiving polarization state that is orthogonal to or low-correlation with the interference polarization direction to reduce interference coupling. Let the interference polarization vector be... The target communication polarization vector is Then the interference coupling degree can be expressed as:
[0092] The system selects the polarization state that minimizes interference coupling while ensuring that the communication polarization matching degree (PM) meets the threshold. Its optimization objective can be expressed as:
[0093] Where PM represents the communication polarization matching degree. To interfere with coupling, and The weighting coefficients are used. This method allows the system to combine polarization reconstruction with anti-interference processing, reducing the receiving coupling of interference signals while ensuring communication polarization matching.
[0094] Example 2: This embodiment applies to Embodiment 1, specifically providing a working scenario for an unmanned aerial vehicle (UAV) telemetry and communication system and method based on predictive polarization reconstruction and polarization matching degree link decision-making. The specific working process of this embodiment is as follows: The UAV's onboard module first collects IMU attitude angles, GPS / BeiDou position, flight speed, mission waypoints, current link quality, and onboard interference detection data, and then the onboard data fusion module generates a state vector.
[0095] Subsequently, the airborne multi-link communication terminal sends the state vector to the ground station prediction and coordination control unit. For example... Figure 4 As shown, the data preprocessing module in the prediction and collaborative control unit performs time synchronization, outlier removal, missing data compensation, coordinate system transformation, and normalization on the input data. Then, the prediction model predicts the future based on the state sequence within the historical time window. The position and attitude of the drone:
[0096] The system calculates the predicted rotation matrix based on the predicted attitude angle:
[0097] And the predicted airborne antenna polarization vector is obtained:
[0098] The system then uses the predicted airborne polarization vector as the target polarization vector for the ground station, and corrects it based on installation errors, channel feedback, and interference polarization.
[0099] Next, the system decomposes the corrected target polarization vector into horizontal and vertical polarization components:
[0100] in:
[0101] After completing the target polarization decomposition, the system calculates the horizontal polarization channel weights and vertical polarization channel weights for each array element based on the target beam direction and target polarization state:
[0102] The ground station's digital phased array antenna controls the amplitude and phase of the horizontal and vertical polarization channels of each element according to the aforementioned weights, thereby synthesizing the target polarization beam. Subsequently, the system acquires the RSSI, SNR, BER, Latency, PM, and interference intensity I of the currently received signal. When detected... , or At that time, the prediction and coordination control unit adjusts the target polarization parameters and array element weights, and repeats the target polarization generation, target polarization decomposition, array element weight calculation and polarization reconstruction process until the link quality meets the preset requirements.
[0103] Meanwhile, the link scoring module calculates a comprehensive score for each communication link:
[0104] The system selects the communication link with the highest overall score as the current working link:
[0105] If the backup link score is higher than the current link score and exceeds a preset threshold, or if it is predicted that the backup link score will be higher than the current link score within a preset timeframe, the system will perform a link switchover. Figure 5 As shown, after the link switch, the system recalculates the target polarization state and regenerates the array element amplitude and phase weights under the corresponding link to ensure that the communication link after the switch still has a high polarization matching degree.
[0106] In a specific scenario, the UAV's IMU collects roll, pitch, and yaw angles at a sampling frequency of 100Hz, while the GPS / BeiDou module collects the UAV's position at a sampling frequency of 10Hz. The system takes data from the most recent 5 seconds, i.e., 500 frames of IMU data and 50 frames of positioning data, and forms a state sequence after time synchronization. The prediction model uses the aforementioned LSTM network, with an input dimension of 13 and a time window length of 500, outputting the predicted attitude and predicted position for the next 3 seconds.
[0107] The system calculates the predicted airborne antenna polarization vector for the next 3 seconds based on the predicted attitude angle and uses it as the ground station target polarization vector. The ground station's digital phased array antenna decomposes the target polarization vector into two orthogonal polarization components, H and V, and generates horizontal and vertical polarization channel weights for each array element based on the H / V amplitude ratio and phase difference. After the antenna completes target polarization beamforming, the receiver feeds back RSSI, SNR, and polarization matching degree PM. If the SNR is below 10dB or the PM is below 0.85, the system readjusts the H / V amplitude ratio and phase difference and updates the digital phased array antenna weights. In this way, the system can complete the ground station polarization state adjustment in advance before the UAV's attitude changes significantly, thus achieving predictive polarization alignment.
[0108] In another specific scenario, the system simultaneously maintains a dedicated data transmission link, a 4G / 5G cellular link, and a satellite link. The system calculates the comprehensive score of the three links in real time. For example, at a certain moment, the dedicated data transmission link score is 0.72, the 4G / 5G cellular link score is 0.81, and the satellite link score is 0.63. Although the dedicated data transmission link is the default primary link, the system selects the 4G / 5G cellular link as the current working link because it has a higher polarization matching degree and a higher comprehensive score under the current drone attitude and electromagnetic environment. When the drone attitude recovers, and the polarization matching degree and comprehensive score of the dedicated data transmission link again exceed those of the 4G / 5G cellular link and exceed the preset switching threshold, the system automatically switches back to the dedicated data transmission link. Thus, the system's link switching is no longer based solely on fixed link priority, but rather on a comprehensive decision based on link quality, polarization matching degree, interference intensity, and predicted score.
[0109] In another specific scenario, the electromagnetic environment monitoring module of the ground station detected the interference intensity of a certain operating frequency band as follows:
[0110] Because the interference intensity is greater than 20 dB, the system determines that there is severe interference in the current operating frequency band. The prediction and coordination control unit then suspends the current operating frequency, calculates the comprehensive score of each backup link, selects the backup link with the highest score and the lowest interference intensity, and recalculates the target polarization state corresponding to that backup link. When the system detects that the interference signal has a specific polarization direction, it further selects the polarization state with a high communication polarization matching degree and a low interference coupling degree, and then sends new array element amplitude and phase weights to the digital phased array antenna array. Through this process, the system completes the joint control of link switching, frequency avoidance, and polarization reconstruction, thereby improving the stability and reliability of UAV telemetry and control communication in a strong interference environment.
[0111] Through this embodiment, the system can adjust the ground station polarization state in advance based on the future changes in the UAV's attitude and position, reducing polarization mismatch losses caused by UAV roll, pitch, and yaw. Simultaneously, the system incorporates polarization matching degree into the multi-link scoring model, ensuring that link switching considers both traditional communication quality and polarization state and future trends. Furthermore, the system can perform frequency hopping enhancement, backup frequency switching, backup link switching, and polarization anti-interference optimization based on electromagnetic environment monitoring results, thereby maintaining the stability of the UAV telemetry and control communication link in complex electromagnetic environments.
[0112] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.
[0113] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.
Claims
1. A UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching, characterized in that, This includes a ground station module, an UAV airborne module, and a multi-link communication network; The ground station module and the UAV onboard module establish a communication connection through at least two communication links in the multi-link communication network; The ground station module includes a prediction and coordination control unit, a digital phased array polarized reconfigurable antenna array, and a multi-link communication unit. The UAV onboard module is used to collect the UAV's attitude data, positioning data, and link status data, and generate a state vector to send to the prediction and coordination control unit. The prediction and cooperative control unit is used to predict the position and attitude angle of the UAV within a preset time period based on the state vector, construct a prediction rotation matrix based on the predicted attitude angle, and calculate the predicted airborne antenna polarization vector based on the preset initial polarization vector of the airborne antenna. The prediction and coordination control unit is also used to generate a target polarization vector based on the predicted airborne antenna polarization vector, decompose the target polarization vector into horizontal polarization components and vertical polarization components, and calculate the horizontal polarization channel weights and vertical polarization channel weights of each element of the digital phased array polarization reconfigurable antenna array, so as to control the digital phased array polarization reconfigurable antenna array to synthesize a target polarization beam that matches the predicted airborne antenna polarization state. The multi-link communication unit is used to collect link quality data for each communication link; The prediction and coordination control unit is also used to calculate the current comprehensive score and the predicted comprehensive score within a preset time period of each communication link based on the link quality data and polarization matching degree, and to perform link switching when the predicted comprehensive score of the backup link is higher than the predicted comprehensive score of the current working link and exceeds a preset threshold.
2. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The UAV onboard module includes an IMU attitude sensor, a GPS / BeiDou positioning module, an onboard data fusion module, and an onboard multi-link communication terminal. The onboard data fusion module is used to synchronize and fuse attitude data, position data, velocity data, link quality data, and interference intensity data in time to generate the state vector.
3. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The digital phased array polarization reconfigurable antenna array includes multiple dual-polarization array elements, each of which includes a horizontal polarization channel and a vertical polarization channel. Each channel is configured with an independent amplitude control unit and a phase control unit. The prediction and coordination control unit determines the amplitude ratio and phase difference between the horizontal polarization component and the vertical polarization component based on the target polarization vector, and calculates the horizontal polarization channel weights and vertical polarization channel weights of each array element accordingly.
4. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The prediction and collaborative control unit uses a time series prediction model to process historical state sequences in order to predict the position and attitude angle of the UAV within a preset time period in the future; the time series prediction model is a Long Short-Term Memory (LSTM) neural network.
5. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The polarization matching degree is calculated based on the polarization mismatch angle between the UAV's airborne antenna polarization vector and the ground station's antenna polarization vector, satisfying the following: PM = |cos(Δα)|² Where Δα is the angle between the polarization vector of the UAV's onboard antenna and the polarization vector of the ground station's antenna, and PM is the polarization matching degree.
6. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The target polarization vector is determined jointly based on the predicted airborne antenna polarization vector, the antenna installation deviation compensation amount, and the link feedback correction amount.
7. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The system also includes a polarization closed-loop feedback module; The polarization closed-loop feedback module is used to collect the received signal strength RSSI, signal-to-noise ratio SNR, bit error rate BER, polarization matching degree PM and interference intensity I of the current communication link, and feed them back to the prediction and coordination control unit. The prediction and collaborative control unit performs polarization closed-loop optimization based on an optimization objective function, which satisfies the following: in, To optimize the objective function value for polarization, For polarization matching degree, For signal-to-noise ratio, For bit error rate, For interference intensity, , , and These are the weighting coefficients for the corresponding parameters; The prediction and coordination control unit adjusts the amplitude ratio and phase difference between the horizontal polarization component and the vertical polarization component according to the optimization objective function, updates the target polarization vector and recalculates the array element weights until the preset communication quality conditions are met.
8. The UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 1, characterized in that, The system also includes an electromagnetic interference detection and avoidance module; the electromagnetic interference detection and avoidance module is used to perform spectrum scanning on the working frequency band and the backup frequency band, and determine the interference level based on the difference between the interference signal power and the noise floor power; when it is determined to be mild interference, the frequency hopping rate is increased; when it is determined to be moderate interference, the system switches to the backup frequency channel; and when it is determined to be severe interference, the system triggers the communication link switch.
9. A UAV telemetry and control system based on polarization adaptation and multi-link intelligent switching according to claim 8, characterized in that, When the interference signal is detected to have polarization characteristics, the electromagnetic interference detection and avoidance module determines the interference polarization vector; The prediction and cooperative control unit is based on the communication polarization matching degree (PM) and interference coupling degree. The target polarization state is jointly determined, and the target polarization state satisfies: in, The optimized target polarization state, For communication polarization matching degree, To interfere with coupling, and These are the weighting coefficients; The interference coupling degree satisfies: in, The target communication polarization vector, For the interference polarization vector; The prediction and coordination control unit selects a target polarization state that reduces interference coupling, provided that the polarization matching degree is satisfied by a preset threshold.
10. A UAV telemetry and control method based on polarization adaptation and multi-link intelligent switching, characterized in that, The system applied to any one of claims 1 to 9 comprises: Acquire the drone's attitude data, positioning data, and link status data, and generate a state vector; Predict the position and attitude angle of the UAV within a preset time period based on the state vector; A prediction rotation matrix is constructed based on the predicted attitude angle, and the prediction airborne antenna polarization vector is calculated based on the preset initial polarization vector of the airborne antenna. The target polarization vector is generated based on the predicted airborne antenna polarization vector; The target polarization vector is decomposed into horizontal polarization components and vertical polarization components, and the horizontal polarization channel weights and vertical polarization channel weights of each element of the digital phased array polarization reconfigurable antenna array are calculated based on the horizontal polarization components and vertical polarization components. The digital phased array polarization reconfigurable antenna array is controlled to form a target polarization beam that matches the predicted polarization state of the airborne antenna based on the horizontal polarization channel weights and vertical polarization channel weights. Obtain link quality data and polarization matching degree for each communication link; The current comprehensive score and the predicted comprehensive score within a preset time period are calculated based on the link quality data and polarization matching degree of each communication link. When the predicted comprehensive score of the backup link is higher than the predicted comprehensive score of the current working link and exceeds a preset threshold, link switching is performed.