High-altitude satellite station and flight and satellite tracking method thereof

Abstract

The invention discloses a high-altitude satellite station and a flying and satellite aligning method thereof, relates to the field of satellite communication, and is used for realizing beyond-visual-range video image acquisition and return under a shielding condition. The high-altitude satellite station comprises a machine body which is integrated with a modem and a host; the antenna feed system is installed on the top of the machine body through the pitching mechanism. The modem is electrically connected with the antenna feeder system and the host respectively; a rotor support is connected to the bottom of the vehicle body, and a plurality of rotors are connected to the rotor support in the circumferential direction. The bottom of the rotor bracket is connected with a battery bracket; an external hanging point is connected below the rotor wing bracket, a Beidou positioning antenna is mounted on the rotor wing bracket, and a flying antenna and a cellular mobile communication antenna are mounted below the rotor wing bracket. Flight of a high-altitude satellite station is subjected to closed-loop control through fuzzy reasoning by means of a PID control strategy, and satellite tracking is achieved through a blind scanning stage, a coarse aiming stage and a tracking stage. According to the invention, beyond-visual-range video image acquisition and return under a shielding condition can be realized, and flight and satellite tracking are stable.

Description

Technical Field

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

[0002] In the event of major disasters such as earthquakes, landslides, debris flows, barrier lakes, dam breaches, and forest fires, ground communication base stations are likely to experience signal interruptions. In this regard, satellite high-altitude monitoring technology can be used to capture the situation in the disaster area in a timely manner. Relevant units also emphasize 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, in areas lacking ground signal coverage, especially when ground signals are interrupted due to major dangers, the cooperation between satellite communication terminals and drones has become an important support means for emergency communication guarantee, data collection, video image return and other scenarios in many fields such as search, rescue, and mapping. However, under such a trend, facing complex and changing application environments, the difficulty of satellite communication terminals in areas such as dense forests, high mountains, and deep ravines due to obstruction has become increasingly prominent. Or when major dangers occur, it is difficult to deploy satellite communication terminals to an ideal location due to factors such as rugged roads and harsh environments. Although the use of drones carrying satellite communication terminals can make up for the problem of limited deployment of satellite communication terminals to a certain extent, the communication and video image data return distance of small and medium-sized drones is limited, and large drones are expensive and have many take-off restrictions, making it difficult for satellite communications to play their due guarantee and support capabilities. Summary of the invention

[0004] The purpose of the present invention is to provide a high-altitude satellite station to achieve beyond-line-of-sight video image acquisition and transmission under occlusion conditions in order to solve the above-mentioned problems.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A high-altitude satellite station, comprising a body, wherein a modem and a host are integrated in the body; a pitch mechanism is provided on the top of the body, and an antenna feed system is installed on the top of the body through the pitch mechanism; the modem is electrically connected to the antenna feed system and the host respectively; and a motor of the pitch mechanism is electrically connected to the host;

[0007] The bottom of the body is connected to a rotor bracket, and a plurality of rotors are connected to the rotor bracket in the circumferential direction, and the motors of the rotors are respectively electrically connected to the main engine;

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

[0009] An external attachment point is connected below the rotor bracket, a Beidou positioning antenna is installed on the rotor bracket, a flying antenna and a cellular mobile communication antenna are installed below the rotor bracket, and the Beidou positioning antenna, the flying antenna and the cellular mobile communication antenna are electrically connected to the host respectively.

[0010] Furthermore, a plurality of rotor quick-release openings are evenly arranged around the circumference of the rotor bracket, and each rotor is connected to the rotor bracket via a corresponding rotor quick-release opening.

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

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

[0013] The following process is executed in a loop:

[0014] Calculate the flight error signal based on the data collected by the sensor, and perform fuzzy quantization processing on the flight error signal to obtain a fuzzy signal;

[0015] Using the fuzzy rule base to infer the fuzzy signal to obtain a fuzzy decision;

[0016] Defuzzifying the fuzzy decision by using a predetermined control strategy calculation method to obtain a motor drive amount;

[0017] The motor drive amount is used to drive the motor compensation.

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

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

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

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

[0022] Determining whether the flight error signal is within a first threshold range, and if not, determining that the fuzzy signal is a fuzzy level corresponding to a maximum control coefficient, and if so, determining whether to enter a tracking state or a non-tracking state according to whether the carrier attitude is isolated;

[0023] For the tracking state, continue to determine whether the flight error signal is within the second threshold range, if not, determine the fuzzy signal as corresponding to the fuzzy level containing only the PD coefficient, if so, continue to determine whether the flight error signal is within the third threshold range; if not, determine the fuzzy signal as corresponding to the fuzzy level containing the PID coefficient, if within the third threshold range, use it 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 the non-tracking state, continue to determine whether the flight error signal is within the fourth threshold range, if not, determine the fuzzy signal to be a fuzzy level corresponding to only the P coefficient, if yes, continue to determine whether the flight error signal is within the fifth threshold range; if not within the fifth threshold range, determine the fuzzy signal to be a fuzzy level corresponding to the PI coefficient, if within the fifth threshold range, then take it 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-band limiting and steady-state control, the fuzzy signal is determined to be a fuzzy level corresponding to the 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] Using a predetermined control strategy calculation method to perform a defuzzification process on the fuzzy decision to calculate the control amount;

[0028] It is determined whether the calculated control amount is within the set threshold. If so, the calculated control amount is used as the motor drive amount. Otherwise, the threshold in the same direction is used as the motor drive amount.

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

[0030] Control the antenna to perform barrel blind scanning at the set azimuth speed and pitch range. After capturing the target RSSI, control the antenna to find the position of the RSSI maximum value through cross-movement.

[0031] Control the antenna to perform step scanning to find the location of the target signal RSSI maximum value;

[0032] The antenna is controlled to move continuously in a diamond shape. Each time it moves, the energy at the four vertices of the diamond shape is compared and the vertex with the maximum energy is selected as the landing point.

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

[0034] Starting from the last vertex of the walking rhombus, a predetermined walking path is used to reach the vertex of maximum energy, and the predetermined walking path at least surrounds an 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. The present invention adopts a Ka-band antenna, which improves efficiency by more than 10% compared with satellite terminals currently on the market.

[0037] 2. The method for hovering and stabilizing the flight of a UAV of the present invention has a dynamically controllable attitude adjustment function, and can perform hovering attitude stabilization adjustment according to the maximum swing angle allowed by the satellite terminal.

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

[0039] 4. The present invention controls dual transmission channels, and guarantees the control channel after BVR, ensuring safe flight to the vicinity of the target area. The image acquisition signal is directly transmitted back through the satellite terminal, and the control end can monitor through the ground network or the network provided by the portable satellite terminal, and adjust the focal length of the image acquisition direction, etc. When flying beyond visual range, if the control signal is suddenly lost, the connection is re-established through the satellite signal and the remote control section, and the return is remotely controlled.

[0040] 5. In areas without ground networks, the present invention provides network coverage through high-altitude satellite stations and realizes cluster collection functions through self-organizing network connections. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0043] Figure 2 This is a side view of a high altitude satellite station.

[0044] Figure 3 It is the satellite tracking signal flow diagram of the high altitude satellite station.

[0045] Figure 4 It is a satellite tracking flow chart of high altitude satellite station.

[0046] Figure 5 It is a flow chart of the fusion algorithm based on space vector matrix transformation and Kalman filter.

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

[0048] Figure 7 It is the flight control flow chart of the high altitude satellite station.

[0049] Figure 8 It is the flow chart for determining the control coefficient. DETAILED DESCRIPTION

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

[0051] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other equivalent or alternative features having similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0052] The present invention is aimed at the emergency communication guarantee needs in complex application environments, and fully utilizes the characteristics of high-throughput satellites with wide bandwidth, large capacity, wide coverage, and high gain. It relies on multiple design points such as satellite station structure, stable flight of unmanned aerial vehicles, and intelligent satellite alignment algorithm of satellite communication terminals to build a high-altitude emergency communication relay platform. Through the construction of the platform, narrowband cluster or LTE base station signal coverage is achieved in the operating area of ​​the high-altitude satellite station, and multiple small unmanned aerial vehicles are controlled to perform cluster collection operations, and over-the-horizon video image collection and transmission under occlusion conditions are completed, thereby effectively enhancing the ability of front-line personnel to carry out emergency guarantee 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 body 9, the bottom of which is mounted on a rotor bracket, and a pitch mechanism 8 is provided on the top of the body 9. A high-gain antenna feed system consisting of an antenna surface 1, a ka feed source 2 and a 4W integrated machine 3 is hinged on the body 9 through the pitch mechanism 8, wherein the ka feed source 2 and the 4W integrated machine 3 are connected as one, the ka feed source 2 is directly opposite to the antenna surface 1, and the antenna surface 1 and the ka feed source 2 are made of carbon fiber composite materials to reduce the weight of the satellite station. The antenna feed system is responsible for completing the communication link connection between the satellite station and the satellite. In the body 9, a modem and a host are integrated, and the modem is electrically connected to the 4W integrated machine 3 and the host, respectively. In addition, the motor of the pitch mechanism 8 is electrically connected to the host in the body 9, so as to adjust the pitch angle of the antenna surface 1 and the ka feed source 2 through the host to complete the satellite search.

[0054] Under the body 9, a plurality of rotors 5 are connected to the circumference of the rotor bracket. The plurality of rotors 5 are evenly arranged in the circumference of the rotor bracket, and the motors of the plurality of rotors 5 are electrically connected to the host in the body 9. A support leg 7 is also connected to the bottom of the rotor bracket to support the takeoff or landing of the high-altitude satellite station. The rotor bracket, the rotor 5 and the support leg 7 can all be made of carbon fiber composite materials to reduce the weight of the satellite station as much as possible while ensuring the strength of the equipment, thereby increasing the endurance time.

[0055] In some preferred embodiments, a plurality of rotor quick-release ports 4 are provided in the circumferential direction of the rotor bracket, and the rotors 5 are connected to the rotor bracket via corresponding rotor quick-release ports 4 , and can also be quickly disassembled from the rotor quick-release ports 4 .

[0056] A battery bracket is connected to the bottom of the rotor bracket, which can also be made of carbon fiber composite materials. The battery bracket is used to install the battery 11, which supplies power to the entire high-altitude satellite station. According to tests, as long as the battery bracket can carry two 1KWh batteries, the high-altitude satellite station can ensure a flight time of no less than 25 minutes under full load.

[0057] An external attachment point 10 is connected below the rotor bracket. The external attachment point 10 can be used to mount a video image pan-tilt head, a surveying and mapping terminal, an infrared search and rescue terminal, etc. according to the emergency communication guarantee requirements in complex application environments.

[0058] In addition, a Beidou positioning antenna 6 is also installed on the rotor bracket, and the Beidou positioning antenna 6 is electrically connected to the main engine in the body 9.

[0059] A flight control antenna 12 is installed under the rotor bracket for receiving control signals from the remote controller, and the flight control antenna 12 is electrically connected to the host in the body 9. A cellular mobile communication antenna 13, such as a 4G / 5G antenna, is also installed under the rotor bracket. The cellular mobile communication antenna 13 is electrically connected to the host in the body 9 and is used to transmit satellite signals received by the antenna feed system to the ground station, or transmit the signals of the ground station to the satellite through the antenna feed system. The cellular mobile communication antenna 13 can achieve cellular mobile communication signal coverage within a range of 5 km.

[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 the satellite using the solution of "open-loop stabilization + closed-loop tracking + sensor fusion".

[0062] Open-loop stabilization is divided into a stabilization loop and a position loop. The mechanism of the stabilization loop is to use the angular velocity provided by the combined inertial measurement unit to directly project it into the antenna coordinate system for angle compensation, so as to keep the beam pointing stable in the inertial space. The position loop stabilization uses the combined inertial measurement unit to obtain the antenna pointing angle through coordinate conversion according to the change of the rotor bracket attitude, and performs strapdown stabilization on the position loop. Open-loop stabilization has the characteristics of high update frequency and rapid adjustment of antenna pointing and rotor bracket attitude. However, due to changes in airflow, drift of inertial devices and other system factors, it is difficult for the antenna feed system on high-altitude satellite stations to maintain satellite stability.

[0063] At this time, when the device completes the initial satellite alignment, it will use closed-loop tracking to perform stability corrections on the antenna pointing and drone attitude, keeping the antenna accurately pointing to the satellite to ensure signal stability.

[0064] Specifically, satellite tracking includes three stages: blind scanning stage, coarse aiming stage and tracking stage.

[0065] like Figure 4 As shown in the figure, in the blind scanning stage, the antenna is controlled to perform barrel blind scanning at the set azimuth speed and pitch range to capture the target RSSI. For example, the blind scanning speed of the antenna azimuth signal is set to 40° / S, and it takes about 9S to scan the azimuth plane once (360°). The barrel scanning is performed within the pitch range of 0° to 100°. The approximate pitch angle can be calculated in combination with the satellite's orbit information. The initial capture of the target RSSI is generally less than 9S. Whether the target RSSI is captured is determined by judging whether the captured RSSI is greater than the threshold. After capturing the target RSSI, the antenna is controlled to find the position of the RSSI maximum value through cross-crossing motion, and the blind scanning stage is transitioned to the coarse aiming stage.

[0066] In the coarse aiming stage, the auxiliary antenna needs to find the RSSI maximum value through cross-movement and then switch to the convergence mode. At this time, the antenna searches for the target RSSI maximum value through step scanning, and switches the RSSI to the horizontal difference and pitch difference as the drive to enter the tracking stage.

[0067] During the tracking phase, the drift problem of the gyroscope attitude measurement was tested, corrected and compensated for its temperature drift characteristics, nonlinearity, lateral axis error, orthogonal error, spatial position of the sensitive axis, etc. Simulated life tests and temperature cycles under various angular rates and angular acceleration impact conditions were also carried out. More rigorous and additional tests, corrections and compensations can be performed according to special needs.

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

[0069] First, the gyroscope is calibrated at full temperature to achieve temperature compensation in the full temperature range. For example, it can ensure that the data is not distorted in an environment of -40℃ to +85℃, and can continuously and stably output navigation information in various harsh environments.

[0070] Secondly, the antenna feed system uses a high-precision inertial module. The gyroscope output reaches a dynamic range of ±500° / S, zero bias stability and repeatability ≤5° / h, and the accelerometer reaches a dynamic range of ±10g, zero bias stability and repeatability ≤0.3mg, which provides a measurement basis for precise antenna alignment. At the same time, it is combined with the space vector matrix transformation and Kalman filter fusion algorithm. The fusion algorithm process is as follows Figure 5 shown.

[0071] The antenna system integrates multiple sensors such as GPS, inertial measurement unit (IMU), and barometric altimeter. By fusing the data of sensors such as IMU and barometric altimeter, the pre-processed multi-sensor data is input into the Kalman filter for fusion. Taking IMU and GPS as an example, IMU can provide high-frequency motion information, but the error will accumulate over time; GPS can provide relatively accurate position and speed information, but the update frequency is low. Kalman filtering uses the prediction information of IMU and the observation information of GPS to obtain more accurate state estimation through continuous prediction and update process.

[0072] During the state estimation process, the parameters of the Kalman filter can be adjusted according to the characteristics and reliability of the sensor. 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 adjusted according to the set step size. By reasonably adjusting the parameters, the advantages of each sensor can be fully utilized to improve the overall performance of the navigation system.

[0073] The experimental results show that after using Kalman filtering for multi-sensor data fusion, Kalman filtering can also improve the reliability and robustness of the navigation system. In the case of sensor failure or data loss, Kalman filtering can still maintain a certain tracking accuracy by fusing the data of other sensors, thereby improving the reliability and robustness of the system. The dynamic alignment accuracy of the antenna is guaranteed to be ≤0.2°, meeting the tracking accuracy requirements.

[0074] In addition, during the tracking phase, the zero point processing of the gyroscope is one of the keys to stabilize the pointing effect of the change in the attitude of the isolation carrier. For the determination of the zero point value of the gyroscope, the system will measure the zero point of the gyroscope when it is turned on. The usual measurement method is to take three hundred (or other numbers) of data for averaging (called sampling value), but due to various factors, such as the self-starting of the gyroscope itself when the power is turned on, the shaking of the antenna, etc., the sampling value will deviate from the actual value, so the system will compare the average value with the gyroscope zero point value stored in the storage chip last time during operation. If the difference between the two is small, the last stored value is selected. If the deviation is large, the sampling value is selected. This method is used in consideration of the actual use of the antenna feed system, that is, if the current use environment of the antenna feed system of the high-altitude satellite station is not much different from the last time, then it is obvious that the last stored gyroscope zero point value is better, so the last stored value is selected, otherwise the sampling value is better, so the sampling value is selected.

[0075] During the tracking phase, the conical tracking mode is used to continuously correct the azimuth and pointing angle of the antenna.

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

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

[0078] Starting from the last vertex of the walking rhombus, a predetermined walking path is used to reach the vertex with the maximum energy, and the predetermined walking path at least surrounds an area of ​​the rhombus. Figure 6 As shown, assume that the antenna is at point A, and walk along diamond ABCD with point A as the reference, and compare the energy of the four vertices:

[0079] If the energy of point A is relatively large at this time, point A is reached through the path ABCDA, and then the energy of the four points is compared in a diamond shape with point A as the reference; if the energy of point B is relatively large at this time, point B is reached through the path AEFCB, and then the energy of the four points is compared in a diamond shape with point B as the reference; if the energy of point C is relatively large at this time, point C is reached through the path AEGHC, and then the energy of the four points is compared in a diamond shape with point C as the reference; if the energy of point D is relatively large at this time, point D is reached through the path AEGID, and then the energy of the four points is compared in a diamond shape with point D as the reference. The circular arc interpolation motion of the cone scan is simplified by adjusting the side length of the diamond, and the tracking convergence speed is improved.

[0080] The prerequisite for stable satellite tracking is that the high-altitude satellite station achieves stable flight.

[0081] The flight method for a high-altitude satellite station to achieve hovering and stable flight proposed in the embodiment of the present application includes:

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

[0083] The following process is executed in a loop:

[0084] The flight error signal is calculated based on the data collected by the sensor, and the flight error signal is fuzzy quantized to obtain a fuzzy signal; the quantized fuzzy signal is an integer level;

[0085] Using the fuzzy rule base to infer the fuzzy signal to obtain a fuzzy decision;

[0086] Defuzzifying the fuzzy decision by using a predetermined control strategy calculation method to obtain a motor drive amount;

[0087] The motor drive amount is used to drive the motor compensation.

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

[0089] In some specific implementations, the flight error signal includes an angular velocity error and a variation of the angular velocity error, which can be measured and calculated by assembling a corresponding inertial navigation sensor on the high-altitude satellite station. The flight control of the high-altitude satellite station adopts a closed-loop control strategy. Figure 7 As shown, the high-altitude satellite station calculates the angular velocity error and error variation according to the sensor data; then the calculated error and error variation are fuzzified to determine the corresponding fuzzy level; then the fuzzy decision is matched in the automatic control rule table in the fuzzy rule base, which is the control coefficient that determines the control change range. According to the commonly used closed-loop control strategy, the closed-loop control here adopts the PID control strategy, so the control coefficient includes three types of PID coefficients, namely, proportional P parameter, integral I parameter and differential D parameter. In addition, in different closed-loop control systems, their own control strategy calculation methods are designed, and the specific control quantity can be obtained based on the input control coefficient. The specific control strategy calculation method is not limited here.

[0090] The control coefficient is matched according to the analog signal, and different flight error signals determine different fuzzy levels. Therefore, when the flight error signal is fuzzy quantized, the corresponding control coefficient has been determined.

[0091] In some embodiments, Figure 8As shown, the flight error signal is fuzzily quantified 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 as the position error decreases. When the position error is large, the integral intensity is weak, and when the position error is small, the integral intensity is enhanced. In this way, on the one hand, it can further reduce the closed-loop overshoot, and on the other hand, it can speed up the closed-loop speed. 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 the steady-state control, determine that the fuzzy signal is the fuzzy level corresponding to the preset limited amplitude output. And the limited amplitude output is correspondingly designed with corresponding control coefficients.

[0096] In addition, when calculating the motor drive amount based on the control coefficient, the maximum or minimum control amount value is also considered, and the control amount that exceeds the threshold is replaced by the threshold. Specifically, the fuzzy decision is defuzzified using a predetermined control strategy calculation method to calculate the control amount; it is determined whether the calculated control amount is within the set threshold. If so, the calculated control amount is used as the motor drive amount, otherwise, the threshold in the same direction is used as the motor drive amount. The so-called same direction means that if the calculated control amount is greater than the maximum threshold, the maximum threshold is used as the motor drive amount, and if the calculated control amount is less than the minimum threshold, the minimum threshold is used as the motor drive amount.

[0097] After compensating the motor drive by outputting the motor drive amount, the compensated data is collected through the sensor to calculate the error, and then PID control is performed according to the calculation result to achieve closed-loop control.

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

[0099] 1) In areas with dense and high trees, a high-altitude satellite station is launched to fly above the trees to perform satellite alignment, and is equipped with a self-organizing network system, narrowband cluster or LTE base station to provide a satellite network for units in the operating area below the high-altitude satellite station.

[0100] 2) Equipped with a high-definition image acquisition terminal, it can perform over-the-horizon image acquisition work when blocked by mountains or trees. After bypassing the mountains and trees, it hovers and deploys satellite equipment to directly transmit the collected images back via satellite, and the remote control terminal only receives location information and remote control information.

[0101] 3) When performing ultra-long-distance flight collection work, if the distance exceeds 10 kilometers and the collected images cannot be transmitted back through the self-organizing network, the collected images will be directly transmitted back through the satellite, and the remote control end will only receive the location information and remote control information. In this scenario, in order to avoid the loss of control signals due to the long flight distance, the ground LTE public network or the ground portable satellite station public network can be provided at the remote control end. When the remote control signal is lost, the high-altitude satellite station will automatically hover and unfold the satellite antenna, communicate with the ground remote control through the Internet, and set the route for return.

[0102] 4) Cooperate with multiple small image data collection drones to perform cluster collection operations beyond the control range of small drones. When multiple drone collection points are required on site and the take-off point is far away, there is no need to use multiple medium-sized drones with long control distances and high costs. Two high-altitude satellite stations can be used to form a team with several small drones. Even if the remote control range of small drones is exceeded, it can be achieved. The implementation method is that the high-altitude satellite station carries self-organizing network equipment. The first one flies to the vicinity of the remote control limit position of the small drone and starts star alignment. The second one continues to fly to the target area until it reaches twice the airborne self-organizing network limit connection distance with the first one, and then hovers to achieve self-organizing network area connection. Satellite Internet is provided in the area, and then the small drone flies along the self-organizing network coverage area of ​​the two high-altitude satellite stations. At the same time, it is ensured that the ground remote control end has an LTE network or satellite Internet network, and remote control is achieved through the Internet. If the target position still cannot be reached, the first one can continue to fly to the target area to form a relay after all the small drones fly to the self-organizing network coverage area of ​​the second high-altitude satellite station.

[0103] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A high altitude satellite station, characterized in that: The invention comprises a body, wherein a modem and a host are integrated in the body; a pitch mechanism is arranged on the top of the body, and an antenna feed system is installed on the top of the body through the pitch mechanism; the modem is electrically connected to the antenna feed system and the host respectively; and a motor of the pitch mechanism is electrically connected to the host; The bottom of the body is connected to a rotor bracket, and a plurality of rotors are connected to the rotor bracket in the circumferential direction, and the motors of the rotors are respectively electrically connected to the main engine; A battery bracket is connected to the bottom of the rotor bracket; An external attachment point is connected below the rotor bracket, a Beidou positioning antenna is installed on the rotor bracket, a flying antenna and a cellular mobile communication antenna are installed below the rotor bracket, and the Beidou positioning antenna, the flying antenna and the cellular mobile communication antenna are electrically connected to the host respectively.

2. The high altitude satellite station according to claim 1, characterized in that: A plurality of rotor quick-release openings are evenly arranged around the circumference of the rotor bracket, and each rotor is connected to the rotor bracket through a corresponding rotor quick-release opening.

3. The method for flying a high-altitude satellite station as claimed in claim 1, characterized in that: include: Build a fuzzy rule base and keep it updated; The following process is executed in a loop: Calculate the flight error signal based on the data collected by the sensor, and perform fuzzy quantization processing on the flight error signal to obtain a fuzzy signal; Reasoning the fuzzy signal using the fuzzy rule base to obtain a fuzzy decision; Defuzzifying the fuzzy decision by using a predetermined control strategy calculation method to obtain a motor drive amount; The motor drive amount is used to drive the motor compensation.

4. The method for flying a high-altitude satellite station as claimed in claim 3, characterized in that: The fuzzy rule base is constructed based on engineering debugging experience records and updated based on actual debugging results.

5. The method for flying a high-altitude satellite station as claimed in claim 3, characterized in that: The flight error signal includes an angular velocity error and a variation of the angular velocity error.

6. The method for flying a high-altitude satellite station as claimed in claim 3, characterized in that: The fuzzy rule base contains the mapping relationship between fuzzy levels and control coefficients; the fuzzy quantization processing of the flight error signal to obtain the fuzzy signal is to fuzzy quantize the flight error signal into the corresponding fuzzy level.

7. The method for flying a high-altitude satellite station as claimed in claim 6, characterized in that: The control coefficient includes three types of PID coefficients; the fuzzy quantization processing of the flight error signal to obtain the fuzzy signal includes: judging whether the flight error signal is within a first threshold range, if not, determining that the fuzzy signal is a fuzzy level corresponding to the maximum control coefficient, and if so, determining whether to enter a tracking state or a non-tracking state according to whether the carrier posture is isolated; For the tracking state, continue to determine whether the flight error signal is within the second threshold range, if not, determine the fuzzy signal as corresponding to the fuzzy level containing only the PD coefficient, if so, continue to determine whether the flight error signal is within the third threshold range; if not, determine the fuzzy signal as corresponding to the fuzzy level containing the PID coefficient, if within the third threshold range, use it 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 the non-tracking state, continue to determine whether the flight error signal is within the fourth threshold range, if not, determine the fuzzy signal to be a fuzzy level corresponding to only the P coefficient, if yes, continue to determine whether the flight error signal is within the fifth threshold range; if not within the fifth threshold range, determine the fuzzy signal to be a fuzzy level corresponding to the PI coefficient, if within the fifth threshold range, then take it 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-band limiting and steady-state control, the fuzzy signal is determined to be a fuzzy level corresponding to the preset limit output.

8. The method for flying a high-altitude satellite station as claimed in any one of claims 3 to 7, characterized in that: The fuzzy decision is defuzzified using a predetermined control strategy calculation method to obtain the motor drive quantity, including: Using a predetermined control strategy calculation method to perform a defuzzification process on the fuzzy decision to calculate the control amount; It is determined whether the calculated control amount is within the set threshold. If so, the calculated control amount is used as the motor drive amount. Otherwise, the threshold in the same direction is used as the motor drive amount.

9. The satellite tracking method of a high-altitude satellite station as claimed in claim 1, characterized in that: include: Control the antenna to perform barrel blind scanning at the set azimuth speed and pitch range. After capturing the target RSSI, control the antenna to find the position of the RSSI maximum value through cross-movement. Control the antenna to perform step scanning to find the location of the target signal RSSI maximum value; The antenna is controlled to move continuously in a diamond shape. Each time it moves, the energy at the four vertices of the diamond shape is compared and the vertex with the maximum energy is selected as the landing point.

10. The satellite tracking method of a high altitude satellite station as claimed in claim 9, characterized in that: The step of selecting the vertex with the maximum energy as the landing point comprises: Starting from the last vertex of the walking rhombus, a predetermined walking path is used to reach the vertex of maximum energy, and the predetermined walking path at least surrounds an area of ​​the rhombus.

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