High-altitude satellite stations and their flight and satellite tracking methods

Abstract

This invention discloses a high-altitude satellite station and its flight and satellite tracking methods, relating to the field of satellite communication, for achieving beyond-line-of-sight video image acquisition and transmission under obstruction conditions. The high-altitude satellite station includes a fuselage integrating a modem and a main unit; an antenna feed system is mounted on the top of the fuselage via a pitch mechanism; the modem is electrically connected to both the antenna feed system and the main unit; a rotor support is connected to the bottom of the fuselage, with multiple rotors circumferentially connected to the rotor support; a battery support is connected to the bottom of the rotor support; external hardpoints are connected below the rotor support, a BeiDou positioning antenna is mounted on the rotor support, and a flight antenna and a cellular mobile communication antenna are mounted below the rotor support. Through fuzzy inference, a PID control strategy is used for closed-loop control of the high-altitude satellite station's flight, achieving satellite tracking through blind scan, coarse aiming, and tracking phases. This invention enables beyond-line-of-sight video image acquisition and transmission under obstruction conditions, with stable flight and satellite tracking.

Description

Technical Field

[0001] This invention relates to the field of satellite communications, and in particular to a high-altitude satellite station and its flight and satellite tracking methods. Background Art

[0002] In response to major emergencies such as earthquakes, landslides, mudslides, barrier lakes, dam breaches, and forest fires, ground communication base stations are highly likely to experience signal interruptions. High-altitude satellite monitoring technology can be used to promptly capture information about the disaster area. Relevant authorities have also emphasized the need to strengthen the deployment and application of advanced emergency communication equipment, such as high-throughput satellites and drone communications.

[0003] With the continuous enrichment of my country's high-throughput satellite resources, satellite communication terminals and drones have become crucial support tools for emergency communication, data acquisition, and video image transmission in many fields, such as search and rescue, surveying, and mapping, especially in areas lacking ground signal coverage and when ground signals are interrupted due to major emergencies. However, under this trend, facing complex and ever-changing application environments, the difficulty of satellite communication terminals engaging with satellites due to obstructions in areas such as dense forests, high mountains, and deep ravines is becoming increasingly prominent. Furthermore, in the event of major emergencies, rugged roads and harsh environments make it difficult to deploy satellite communication terminals to ideal locations. While using drones to carry satellite communication terminals can alleviate the deployment limitations of satellite communication terminals to some extent, small and medium-sized drones have limited communication and video image data transmission distances, while large drones are expensive and have numerous takeoff restrictions, making it difficult for satellite communication to fully realize its intended support capabilities. Summary of the Invention

[0004] The purpose of this invention is to provide a high-altitude satellite station to address the aforementioned problems, enabling the acquisition and transmission of beyond-line-of-sight video images under obstructed conditions.

[0005] The technical solution adopted in this invention is as follows:

[0006] A high-altitude satellite station includes a body, in which a modem and a main unit are integrated; a pitch mechanism is provided on the top of the body, and an antenna feed system is mounted on the top of the body through the pitch mechanism; the modem is electrically connected to the antenna feed system and the main unit respectively; the motor of the pitch mechanism is electrically connected to the main unit.

[0007] The bottom of the fuselage is connected to a rotor bracket, and multiple rotors are connected to the rotor bracket in the circumferential direction. The motor of each rotor is electrically connected to the main unit.

[0008] A battery bracket is connected to the bottom of the rotor support;

[0009] An external mounting point is connected to the lower part of the rotor support. A Beidou positioning antenna is installed on the rotor support. An airborne antenna and a cellular mobile communication antenna are installed below the rotor support. The Beidou positioning antenna, the airborne antenna, and the cellular mobile communication antenna are electrically connected to the main unit.

[0010] Furthermore, the rotor support is evenly provided with multiple rotor quick-release ports in the circumference, and each rotor is connected to the rotor support through the corresponding rotor quick-release port.

[0011] The present invention also provides a method for flying a high-altitude satellite station, comprising:

[0012] Build a fuzzy rule base and keep it constantly updated;

[0013] The following process is executed repeatedly:

[0014] The flight error signal is calculated based on the data collected by the sensor, and the flight error signal is then subjected to fuzzy quantization to obtain a fuzzy signal.

[0015] The fuzzy signal is inferred using the fuzzy rule base to obtain a fuzzy decision;

[0016] The fuzzy decision is defuzzified using a predetermined control strategy calculation method to obtain the motor drive quantity;

[0017] The motor drive quantity is used to drive motor compensation.

[0018] Furthermore, the fuzzy rule base is constructed based on engineering debugging experience records and updated according to actual debugging results.

[0019] Furthermore, the flight error signal includes angular velocity error and the amount of change in angular velocity error.

[0020] Furthermore, the fuzzy rule base contains a mapping relationship between fuzzy levels and control coefficients; the fuzzy signal obtained by performing fuzzy quantization on the flight error signal is to fuzzy quantize the flight error signal into the corresponding fuzzy level.

[0021] Furthermore, the control coefficients include three types of PID coefficients; the fuzzy quantization processing of the flight error signal to obtain the fuzzy signal includes:

[0022] Determine whether the flight error signal is within the first threshold range. If not, determine that the fuzzy signal is the fuzzy level corresponding to the maximum control coefficient. If yes, determine whether to enter the tracking state or the non-tracking state based on whether the carrier attitude is isolated.

[0023] For the tracking state, it is further determined whether the flight error signal is within the second threshold range. If not, the fuzzy signal is determined to be a fuzzy level corresponding to only PD coefficients. If yes, it is further determined whether the flight error signal is within the third threshold range. If not within the third threshold range, the fuzzy signal is determined to be a fuzzy level corresponding to PID coefficients. If within the third threshold range, it is used as a dead zone limit. The second threshold range is within the first threshold range, and the third threshold range is within the second threshold range.

[0024] For non-tracking states, it is further determined whether the flight error signal is within the fourth threshold range. If not, the fuzzy signal is determined to be a fuzzy level corresponding to only the P coefficient. If yes, it is further determined whether the flight error signal is within the fifth threshold range. If not within the fifth threshold range, the fuzzy signal is determined to be a fuzzy level corresponding to the PI coefficient. If within the fifth threshold range, it is used as steady-state control. The fourth threshold range is within the first threshold range, and the fifth threshold range is within the fourth threshold range.

[0025] For dead zone limitation and steady-state control, the fuzzy signal is determined as the fuzzy level of the corresponding preset limit output.

[0026] Furthermore, the fuzzy decision is defuzzified using a predetermined control strategy calculation method to obtain the motor drive quantity, including:

[0027] The fuzzy decision is defuzzified using a predetermined control strategy calculation method to calculate the control quantity;

[0028] Determine whether the calculated control quantity is within the set threshold. If so, use the calculated control quantity as the motor drive quantity; otherwise, use the threshold in the same direction as the motor drive quantity.

[0029] The present invention also provides a satellite tracking method for a high-altitude satellite station, comprising:

[0030] The control antenna performs a barrel blind scan with a set azimuth angular velocity and elevation range. After acquiring the target RSSI, the control antenna finds the location of the RSSI maximum value through a cross-shaped movement.

[0031] The antenna is controlled to perform step scans to locate the location of the maximum RSSI value of the target signal;

[0032] The control antenna continuously moves in a rhombus shape. Each time it moves, the energy at the four vertices of the rhombus is compared, and the vertex with the highest energy is selected as the landing point.

[0033] Furthermore, selecting the vertex with the maximum energy as the landing point includes:

[0034] Starting from the last vertex of the walking rhombus, proceed along a predetermined walking path to the vertex of maximum energy, the predetermined walking path encompassing at least one area of ​​the rhombus.

[0035] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0036] 1. This invention uses a Ka-band antenna, which improves efficiency by more than 10% compared to satellite terminals currently on the market.

[0037] 2. The hovering and stable flight method of the UAV of the present invention has a dynamic and controllable attitude adjustment function, which can make stable hovering attitude adjustment according to the maximum swing angle allowed by the satellite terminal.

[0038] 3. This invention can be used in all dense forests, as long as the drone can rise to the treetops and be attached to the self-organizing network as the network extension center, it can cover the surrounding area from top to bottom. The 1.4GHz self-organizing network with 8W power amplifier output can cover an area with a radius of no less than 5km.

[0039] 4. This invention features dual-channel control and transmission, ensuring a secure control channel even after beyond visual line of sight (BVR) to guarantee safe flight to the vicinity of the target area. Image acquisition signals are directly transmitted back via a satellite terminal, while the control unit can monitor and adjust image acquisition direction and focus via a terrestrial network or a network provided by a portable satellite terminal. In the event of a sudden loss of control signal during BVR flight, a connection is re-established via satellite signal and remote control, enabling remote control for return to base.

[0040] 5. In areas without terrestrial networks, this invention provides network coverage through high-altitude satellite stations and enables cluster data acquisition through self-organizing network connections. Attached Figure Description

[0041] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0042] Figure 1 It is a vertical image of a high-altitude satellite.

[0043] Figure 2 This is a side view of an upper-altitude satellite station.

[0044] Figure 3 This is a flow diagram of satellite tracking signals from an upper-altitude satellite station.

[0045] Figure 4 This is a flowchart of satellite tracking process for high-altitude satellite stations.

[0046] Figure 5 This is a flowchart of an algorithm based on the fusion of spatial vector matrix transformation and Kalman filtering.

[0047] Figure 6 This is a diagram of the diamond-shaped walking path during cone tracking by a high-altitude satellite station.

[0048] Figure 7 This is a flowchart of the flight control process for a high-altitude satellite station.

[0049] Figure 8 This is a flowchart for determining the control coefficients. Detailed Implementation

[0050] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0051] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0052] This invention addresses the emergency communication support needs in complex application environments. It fully leverages the wide bandwidth, large capacity, broad coverage, and high gain of high-throughput satellites, and relies on several design elements, including satellite station structure, stable UAV flight, and intelligent satellite communication terminal alignment algorithms, to construct a high-altitude emergency communication relay platform. Through the platform's construction, narrowband trunking or LTE base station signal coverage is achieved within the high-altitude satellite station's operating area. Multiple small UAVs are controlled to perform cluster data acquisition operations, completing beyond-line-of-sight video image acquisition and transmission under obstructed conditions, thereby effectively enhancing the ability of frontline personnel to conduct emergency support work in complex environments and conditions.

[0053] like Figure 1 , Figure 2 As shown, the hardware structure of the high-altitude satellite station includes a fuselage 9, the bottom of which is mounted on a rotor support. A pitch mechanism 8 is located on the top of the fuselage 9. A high-gain antenna feed system, consisting of an antenna surface 1, a Ka feed 2, and a 4W integrated unit 3, is hinged to the fuselage 9 via this pitch mechanism 8. The Ka feed 2 and the 4W integrated unit 3 are connected as a single unit, with the Ka feed 2 facing the antenna surface 1. The antenna surface 1 and the Ka feed 2 are made of carbon fiber composite material to reduce the weight of the satellite station. This antenna feed system is responsible for establishing the communication link between the satellite station and the satellite. Inside the fuselage 9, a modem and a main unit are integrated. The modem is electrically connected to the 4W integrated unit 3 and the main unit, respectively. Furthermore, the motor of the pitch mechanism 8 is electrically connected to the main unit inside the fuselage 9, allowing the main unit to adjust the pitch angle of the antenna surface 1 and the Ka feed 2 to complete satellite search.

[0054] Below the fuselage 9, multiple rotors 5 are circumferentially connected to the rotor support. These rotors 5 are evenly arranged around the circumference of the rotor support, and their motors are electrically connected to the main unit inside the fuselage 9. Support legs 7 are also connected to the bottom of the rotor support for supporting the high-altitude satellite station during takeoff and landing. The rotor support, rotors 5, and support legs 7 can all be made of carbon fiber composite materials to minimize the weight of the satellite station while ensuring equipment strength and improving endurance.

[0055] In some preferred embodiments, a plurality of rotor quick-release ports 4 are provided in the circumferential direction of the rotor support. The rotors 5 are respectively connected to the rotor support through the corresponding rotor quick-release ports 4. Similarly, they can also be quickly disassembled from the rotor quick-release ports 4.

[0056] A battery bracket, also made of carbon fiber composite material, is connected to the bottom of the rotor support. This battery bracket houses battery 11, which powers the entire high-altitude satellite station. Tests have shown that the battery bracket, capable of holding two 1kWh batteries, can guarantee the high-altitude satellite station a minimum operating time of 25 minutes under full load.

[0057] An external attachment point 10 is connected below the rotor support. This external attachment point 10 can be used to mount video image pan-tilt units, measurement and mapping terminals, infrared search and rescue terminals, etc., according to the emergency communication support needs in complex application environments.

[0058] In addition, a Beidou positioning antenna 6 is installed on the rotor support, which is electrically connected to the main unit in the fuselage 9.

[0059] A flight control antenna 12 is installed below the rotor support to receive control signals from the remote controller. This flight control antenna 12 is electrically connected to the main unit in the airframe 9. A cellular mobile communication antenna 13, such as a 4G / 5G antenna, is also installed below the rotor support. This cellular mobile communication antenna 13 is electrically connected to the main unit in the airframe 9 and is used to transmit satellite signals received by the antenna system to the ground station, or to transmit signals from the ground station to the satellite via the antenna system. The cellular mobile communication antenna 13 can achieve cellular mobile communication signal coverage within a 5km range.

[0060] As a relay station between satellites and ground stations, high-altitude satellite stations need to be able to achieve stable flight and stable tracking of satellites.

[0061] like Figure 3 As shown, in this embodiment, the high-altitude satellite station is designed to track satellites using a scheme of "open-loop stabilization + closed-loop tracking + sensor fusion".

[0062] Open-loop stabilization consists of a stabilization loop and a position loop. The stabilization loop works by directly projecting the angular velocity provided by the integrated inertial measurement unit (IMU) onto the antenna coordinate system for angle compensation, maintaining beam pointing stability in inertial space. Position loop stabilization utilizes the IMU to obtain the antenna pointing angle based on the rotor support attitude changes through coordinate transformation, performing strapdown stabilization on the position loop. Open-loop stabilization features a high update frequency and rapid adjustment of antenna pointing and rotor support attitude. However, due to changes in airflow, inertial device drift, and other system factors, it is difficult for antenna feeder systems mounted on high-altitude satellite stations to maintain satellite alignment stability.

[0063] Once the device completes the initial satellite alignment, closed-loop tracking will be used to perform stability correction on the antenna pointing and the UAV attitude, ensuring that the antenna always points accurately at the satellite and guarantees signal stability.

[0064] Specifically, satellite tracking includes three phases: blind scan phase, coarse aiming phase, and tracking phase.

[0065] like Figure 4 As shown, during the blind scan phase, the control antenna performs a barrel scan at a set azimuth angular velocity and elevation range to acquire the target RSSI. For example, if the antenna azimuth signal blind scan speed is set to 40° / s, a complete azimuth scan (360°) takes approximately 9 seconds. A barrel scan is performed within the elevation range of 0° to 100°. Combined with the satellite's orbital information, the approximate elevation angle can be calculated. Initial target RSSI acquisition typically occurs within 9 seconds. Whether the acquired RSSI is greater than a threshold is used to determine if the target RSSI has been acquired. After acquiring the target RSSI, the control antenna uses a cross-shaped movement to find the location of the RSSI maximum value, at which point the blind scan phase transitions to the coarse aiming phase.

[0066] During the coarse aiming phase, the auxiliary antenna needs to find the maximum RSSI value through cross-shaped movement and then switch to convergence mode. At this time, the antenna finds the maximum RSSI value of the target through step scanning and switches RSSI to horizontal difference and pitch difference as the driving force to enter the tracking phase.

[0067] During the tracking phase, the drift problem of gyroscope attitude measurement was addressed by testing, correcting, and compensating for its temperature drift characteristics, nonlinearity, horizontal axis error, orthogonality error, and spatial position of the sensitive axis. Simulated life tests and temperature cycling were also conducted under various angular rate and angular acceleration impact conditions. More rigorous and extensive testing, correction, and compensation can be performed according to specific needs.

[0068] The correction of gyroscope attitude drift specifically includes:

[0069] First, the gyroscope is calibrated for full temperature range, enabling temperature compensation across the entire temperature spectrum. For example, it ensures data integrity from -40℃ to +85℃, allowing for continuous and stable output of navigation information in various harsh environments.

[0070] Secondly, the antenna feed system employs a high-precision inertial module, with gyroscope output achieving a dynamic range of ±500° / s, zero-bias stability and repeatability ≤5° / h, and accelerometer achieving a dynamic range of ±10g, with zero-bias stability and repeatability ≤0.3mg, providing measurement basis for precise antenna alignment. Simultaneously, it utilizes a fusion algorithm based on space vector matrix transformation and Kalman filtering, the process of which is as follows: Figure 5 As shown.

[0071] The antenna system integrates multiple sensors, including GPS, inertial measurement unit (IMU), and barometric altimeter. By fusing data from the IMU and altimeter, the pre-processed multi-sensor data is input into a Kalman filter for fusion. Taking IMU and GPS as examples, the IMU can provide high-frequency motion information, but errors accumulate over time; GPS can provide relatively accurate position and velocity information, but its update frequency is low. The Kalman filter utilizes the predictive information from the IMU and the observational information from the GPS, obtaining a more accurate state estimate through a continuous prediction and update process.

[0072] During state estimation, the parameters of the Kalman filter can be adjusted based on the characteristics and reliability of the sensors. For sensors with high accuracy but susceptible to interference (such as GPS), their observation noise covariance can be appropriately reduced; for sensors with good stability but slightly lower accuracy (such as IMU), their weight in state estimation can be appropriately increased. The adjustment process can be carried out according to the set step size. By reasonably adjusting the parameters, the advantages of each sensor can be fully utilized, improving the overall performance of the navigation system.

[0073] Experimental results show that Kalman filtering can improve the reliability and robustness of navigation systems by fusing multi-sensor data. Even in the event of sensor failure or data loss, Kalman filtering can maintain a certain level of tracking accuracy by fusing data from other sensors, thereby improving system reliability and robustness. The system ensures that the antenna dynamic alignment accuracy is ≤0.2°, meeting the tracking accuracy requirements.

[0074] Furthermore, during the tracking phase, gyroscope zero-point processing is one of the key factors for stabilizing pointing by isolating changes in the carrier's attitude. To determine the gyroscope zero-point value, the system measures the gyroscope zero-point upon power-up. The usual method is to average three hundred (or other) data points (referred to as the sampled value). However, due to various factors, such as the gyroscope's self-starting upon power-up and antenna vibration, the sampled value may deviate from the actual value. Therefore, during system operation, the average value is compared with the previously stored gyroscope zero-point value in the memory chip. If the difference is small, the previously stored value is selected; if the deviation is large, the sampled value is selected. This method takes into account the actual usage of the antenna feeder system. If the current operating environment of the high-altitude satellite station's antenna feeder system is not significantly different from the previous one, then the previously stored gyroscope zero-point value is obviously better, and therefore selected; conversely, if the sampled value is better, it is selected.

[0075] During the tracking phase, a conical tracking mode is used to continuously correct the antenna's azimuth and pointing angles.

[0076] The cone tracking mode controls the antenna to continuously move in a rhombus shape. Each time it moves, it compares the energy at the four vertices of the rhombus and selects the vertex with the highest energy as the landing point, so that the antenna points to the point with the strongest energy each time.

[0077] Methods for determining the landing point in cone tracking mode include:

[0078] Starting from the last vertex of the walking rhombus, proceed along a predetermined path to the vertex of maximum energy, said predetermined path circling at least one area of ​​the rhombus. For example... Figure 6 As shown, suppose the antenna is currently at point A. Using point A as a reference, traverse a rhombus ABCD and compare the energy levels at the four vertices:

[0079] If point A has a relatively high energy, then proceed through path ABCDA to reach point A, and then continue traversing the rhombus with point A as the reference to compare the energy of the four points. If point B has a relatively high energy, then proceed through path AEFCB to reach point B, and then continue traversing the rhombus with point B as the reference to compare the energy of the four points. If point C has a relatively high energy, then proceed through path AEGHC to reach point C, and then continue traversing the rhombus with point C as the reference to compare the energy of the four points. If point D has a relatively high energy, then proceed through path AEGID to reach point D, and then continue traversing the rhombus with point D as the reference to compare the energy of the four points. By adjusting the side length of the rhombus, the circular interpolation motion of the conical scan is simplified, improving the tracking convergence speed.

[0080] For satellite tracking to be stable, the high-altitude satellite station must be able to fly stably.

[0081] The flight method for achieving hovering and stable flight of a high-altitude satellite station proposed in this application includes:

[0082] Build a fuzzy rule base and keep it constantly updated;

[0083] The following process is executed repeatedly:

[0084] The flight error signal is calculated based on the data collected by the sensor, and the flight error signal is subjected to fuzzy quantization to obtain a fuzzy signal; the quantized fuzzy signal is of integer order.

[0085] The fuzzy signal is inferred using the fuzzy rule base to obtain a fuzzy decision;

[0086] The fuzzy decision is defuzzified using a predetermined control strategy calculation method to obtain the motor drive quantity;

[0087] The motor drive quantity is used to drive motor compensation.

[0088] The so-called fuzzy rule base contains the mapping relationship between fuzzy levels and control coefficients. It is usually built based on engineering debugging experience records and is continuously adjusted and updated according to the actual debugging situation. It is used to match the control coefficients that match the error level of the flight error signal, that is, the adjustment range.

[0089] In some specific implementations, the flight error signal includes angular velocity error and the change in angular velocity error, which can be measured and calculated by equipping the high-altitude satellite station with appropriate inertial navigation sensors. The flight control of the high-altitude satellite station employs a closed-loop control strategy. For example... Figure 7 As shown, the high-altitude satellite station calculates the angular velocity error and error change based on sensor data. The calculated error and error change are then fuzzified to determine the corresponding fuzziness level. Finally, the fuzzy decision is matched using the automatic control rule table in the fuzzy rule base. This decision is the control coefficient that determines the control change amplitude. Based on the commonly used closed-loop control strategy, the closed-loop control here adopts a PID control strategy. Therefore, the control coefficients include three types of PID coefficients: proportional (P) parameters, integral (I) parameters, and derivative (D) parameters. Furthermore, different closed-loop control systems have their own control strategy calculation methods, which derive the specific control quantity based on the input control coefficients. No specific control strategy calculation method is limited here.

[0090] The control coefficients are matched based on the analog signals, and different flight error signals determine different fuzziness levels. Therefore, the corresponding control coefficients are determined when the flight error signals are subjected to fuzzy quantization.

[0091] In some embodiments, such as Figure 8As shown, the flight error signal is subjected to fuzzy quantization to obtain a fuzzy signal, including:

[0092] Judge whether the flight error signal is less than E1 (i.e., within the first threshold range). If not, it means that the error is still large at this time and the distance from the target position is still far. At this time, determine that the fuzzy signal is the fuzzy level corresponding to the maximum control coefficient to achieve the fastest closed-loop. If so, determine whether to enter the tracking state or the non-tracking state according to whether the carrier attitude is isolated. According to whether the carrier attitude is isolated, the working state is divided into the tracking state and the non-tracking state, and the characteristics of these two working states are quite different. In the non-tracking state, the requirement for closed-loop accuracy is greater than the requirement for rapidity; while in the tracking state, the position command will change rapidly with the attitude of the carrier, and the requirement for the response speed of the system is higher. Therefore, two modes are set, corresponding to different position loop schemes in different working states of the system.

[0093] For the tracking state, continue to judge whether the flight error signal is less than E2 (i.e., within the second threshold range), E2 < E1. If not, determine that the fuzzy signal is the fuzzy level corresponding to only the PD coefficient, that is, use the P parameter and the D parameter for adjustment to quickly reduce the error. The design principle of this integral intensity function is: let the integral degree gradually increase with the decrease of the position error. When the position error is large, the integral intensity is weak, and when the position error is small, the integral intensity is enhanced. This can further reduce the closed-loop overshoot on the one hand and accelerate the closed-loop speed on the other hand. If so, continue to judge whether the flight error signal is less than E3 (i.e., within the third threshold range), E3 < E2. If not less than, determine that the fuzzy signal is the fuzzy level corresponding to the PID coefficient, and at this time, PID control is adopted. If less than, it is used as a dead zone limit, indicating that the input quantity is too small.

[0094] For the non-tracking state, continue to judge whether the flight error signal is less than E4 (i.e., within the fourth threshold range), E4 < E1. If not, determine that the fuzzy signal is the fuzzy level corresponding to only the P coefficient, and only use the P parameter for adjustment. If so, continue to judge whether the flight error signal is less than E5 (i.e., within the fifth threshold range), E5 < E4; if not less than, determine that the fuzzy signal is the fuzzy level corresponding to the PI coefficient, and use the P parameter and the I parameter for adjustment. If less than, it is used as a steady-state control.

[0095] For the dead zone limit and steady-state control, determine that the fuzzy signal is the fuzzy level corresponding to the preset limited output. And the limited output is correspondingly designed with corresponding control coefficients.

[0096] Furthermore, when calculating the motor drive quantity based on the control coefficient, the maximum or minimum control quantity value is also considered, and control quantities exceeding the threshold are replaced with the threshold value. Specifically, a predetermined control strategy calculation method is used to defuzzify the fuzzy decision and calculate the control quantity; it is then determined whether the calculated control quantity is within a set threshold. If so, the calculated control quantity is used as the motor drive quantity; otherwise, the threshold in the same direction is used as the motor drive quantity. "Same direction" means that if the calculated control quantity is greater than the maximum threshold, the maximum threshold is used as the motor drive quantity; if the calculated control quantity is less than the minimum threshold, the minimum threshold is used as the motor drive quantity.

[0097] After compensating the motor drive by outputting motor drive quantity, the compensated data is collected by sensors to calculate the error, and then PID control is performed based on the calculation results to achieve closed-loop control.

[0098] This invention can be applied in the following scenarios:

[0099] 1) In areas with dense and tall trees, take off from high-altitude satellite stations, fly above the trees to conduct satellite alignment, and carry self-organizing network systems, narrowband trunking, or LTE base stations to provide satellite networks for units in the working area below the high-altitude satellite stations.

[0100] 2) Equipped with a high-definition image acquisition terminal, it performs beyond-line-of-sight image acquisition when obstructed by mountains or forests. After bypassing mountains and forests, it hovers and deploys satellite equipment, transmitting the acquired images directly back via satellite. The remote control terminal only receives location and remote control information.

[0101] 3) For ultra-long-distance flight data collection exceeding 10 kilometers, where image transmission via a self-organizing network is not feasible, the images are transmitted directly via satellite. The remote control unit only receives location and remote control information. To prevent control signal loss due to excessive flight distance, a terrestrial LTE public network or a portable ground satellite station's public network can be provided at the remote control unit. When the remote control signal is lost, the high-altitude satellite station will automatically hover and deploy its satellite antenna to communicate with the ground remote control via the internet, and a route can be set for return.

[0102] 4) Collaborate with multiple small image data acquisition drones for swarm data acquisition operations exceeding the control range of individual drones. When multiple drone acquisition points are required on-site, and the takeoff points are far apart, it is unnecessary to use multiple costly medium-sized drones with long control distances. Instead, several small drones can be grouped together using two high-altitude satellite stations. This can be achieved even beyond the remote control range of the small drones. The method involves the high-altitude satellite stations carrying self-organizing network equipment. The first station flies to near the remote control limit of the small drones and engages with the satellite. The second station continues to fly towards the target area until it reaches twice the connection limit of the first station's onboard self-organizing network, then hovers and engages with the satellite to establish a self-organizing network connection within the area, with satellite internet provided. The small drones then fly along the self-organizing network coverage area of ​​the two high-altitude satellite stations, while ensuring that the ground remote control terminal has an LTE network or satellite internet network for remote control via the internet. If the target location still cannot be reached, the first drone can continue flying towards the target area after all the small drones have reached the self-organizing network coverage area of ​​the second high-altitude satellite station, forming a relay.

[0103] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A high-altitude satellite station, characterized in that, The device includes a main body, which integrates a modem and a host; a pitch mechanism is provided on the top of the main body, and an antenna feed system is mounted on the top of the main body through the pitch mechanism; the modem is electrically connected to the antenna feed system and the host respectively; the motor of the pitch mechanism is electrically connected to the host. The bottom of the fuselage is connected to a rotor bracket, and multiple rotors are connected to the rotor bracket in the circumferential direction. The motor of each rotor is electrically connected to the main unit. A battery bracket is connected to the bottom of the rotor support; An external mounting point is connected to the lower part of the rotor support, a Beidou positioning antenna is installed on the rotor support, and a flying antenna and a cellular mobile communication antenna are installed below the rotor support. The Beidou positioning antenna, the flying antenna, and the cellular mobile communication antenna are electrically connected to the main unit respectively. The flight method of the high-altitude satellite station includes: A fuzzy rule base is constructed and continuously updated; the fuzzy rule base contains the mapping relationship between fuzziness levels and control coefficients. The following process is executed repeatedly: The flight error signal is calculated based on the data collected by the sensor, and the flight error signal is subjected to fuzzy quantization processing to obtain a fuzzy signal; the fuzzy quantization processing of the flight error signal to obtain a fuzzy signal is to fuzzy quantize the flight error signal into the corresponding fuzziness level; The fuzzy signal is inferred using the fuzzy rule base to obtain a fuzzy decision; The fuzzy decision is defuzzified using a predetermined control strategy calculation method to obtain the motor drive quantity; The motor drive quantity is used to drive motor compensation.

2. The high-altitude satellite station as described in claim 1, characterized in that, The rotor support is evenly provided with multiple rotor quick-release ports in the circumference, and each rotor is connected to the rotor support through the corresponding rotor quick-release port.

3. The high-altitude satellite station as described in claim 1, characterized in that, The fuzzy rule base is constructed based on engineering debugging experience records and updated according to actual debugging results.

4. The high-altitude satellite station as described in claim 1, characterized in that, The flight error signal includes angular velocity error and the amount of change in angular velocity error.

5. The high-altitude satellite station as described in claim 1, characterized in that, The control coefficients include three types of coefficients: PID, FIG, and FIG; the fuzzy signal obtained by fuzzy quantization of the flight error signal includes: Determine whether the flight error signal is within the first threshold range. If not, determine that the fuzzy signal is the fuzzy level corresponding to the maximum control coefficient. If yes, determine whether to enter the tracking state or the non-tracking state based on whether the carrier attitude is isolated. For the tracking state, it is further determined whether the flight error signal is within the second threshold range. If not, the fuzzy signal is determined to be a fuzzy level corresponding to only PD coefficients. If yes, it is further determined whether the flight error signal is within the third threshold range. If not within the third threshold range, the fuzzy signal is determined to be a fuzzy level corresponding to PID coefficients. If within the third threshold range, it is used as a dead zone limit. The second threshold range is within the first threshold range, and the third threshold range is within the second threshold range. For non-tracking states, it is further determined whether the flight error signal is within the fourth threshold range. If not, the fuzzy signal is determined to be a fuzzy level corresponding to only the P coefficient. If yes, it is further determined whether the flight error signal is within the fifth threshold range. If not within the fifth threshold range, the fuzzy signal is determined to be a fuzzy level corresponding to the PI coefficient. If within the fifth threshold range, it is used as steady-state control. The fourth threshold range is within the first threshold range, and the fifth threshold range is within the fourth threshold range. For dead zone limitation and steady-state control, the fuzzy signal is determined as the fuzzy level of the corresponding preset limit output.

6. The high-altitude satellite station as described in any one of claims 1-5, characterized in that, The fuzzy decision is defuzzified using a predetermined control strategy calculation method to obtain the motor drive quantity, including: The fuzzy decision is defuzzified using a predetermined control strategy calculation method to calculate the control quantity; Determine whether the calculated control quantity is within the set threshold. If so, use the calculated control quantity as the motor drive quantity; otherwise, use the threshold in the same direction as the motor drive quantity.

7. The satellite tracking method for a high-altitude satellite station as described in claim 1, characterized in that, include: The control antenna performs a barrel blind scan with a set azimuth angular velocity and elevation range. After acquiring the target RSSI, the control antenna finds the location of the RSSI maximum value through a cross-shaped movement. The antenna is controlled to perform step scans to locate the location of the maximum RSSI value of the target signal; The control antenna continuously moves in a rhombus shape. Each time it moves, the energy at the four vertices of the rhombus is compared, and the vertex with the highest energy is selected as the landing point.

8. The satellite tracking method for a high-altitude satellite station as described in claim 7, characterized in that, The selection of the vertex with the highest energy as the landing point includes: Starting from the last vertex of the walking rhombus, proceed along a predetermined walking path to the vertex of maximum energy, the predetermined walking path encompassing at least one area of ​​the rhombus.

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