A method and system for low-altitude unmanned aerial vehicle inspection and control of low-orbit satellite communication

Abstract

This invention discloses a method and system for low-altitude unmanned aerial vehicle (UAV) inspection and control using low-Earth orbit (LEO) satellite communication, relating to the field of inspection and control technology. The method includes: calculating the relative position and satellite-to-ground link margin between the UAV and each visible satellite based on the inspection task; generating a spatiotemporal four-dimensional link budget table; dividing the communication area of ​​the mission route into three communication zones; generating pre-set flight command packets for each communication void zone; encoding these packets; and issuing them via dual independent satellite-to-ground links during a multi-satellite co-view window. After the UAV enters a communication void zone and loses connection with the satellite, it invokes the pre-set flight command packets for autonomous flight. After flying out of the communication void zone and reconnecting with the satellite, it transmits its flight trajectory back to the ground control center for comparison, then resumes normal remote control mode and retransmits complete inspection data. This invention can avoid the risk of UAV disconnection and loss of control caused by communication voids resulting from dynamic LEO satellite coverage, improving the inherent safety of UAV inspection operations in remote areas.

Description

Technical Field

[0001] This invention relates to the field of inspection and control technology, and in particular to a method and system for inspection and control of low-altitude unmanned aerial vehicles using low-orbit satellite communication. Background Technology

[0002] With the development of the low-altitude economy, routine inspections of cross-border oil pipelines and ultra-long-distance ultra-high-voltage power lines using drones have become an industry necessity. To address the problem of beyond-line-of-sight control of drones in areas without terrestrial network coverage (such as deserts, Gobi, and oceans), the industry has begun to introduce low-Earth orbit satellite constellations as relay communication links.

[0003] However, low-Earth orbit (LEO) satellite networks have highly dynamic topology characteristics: the overhead time of a single satellite relative to the ground is typically only 10-20 minutes. For drones performing long-distance inspection missions, a single mission often lasts more than 2 hours, meaning that the drone needs to undergo multiple satellite handovers during a single mission. Current technologies typically use the ground core network for route reselection when handling inter-satellite handovers, a process that can lead to communication interruptions lasting from seconds to minutes. During this period, the drone is in a "disconnected" state, and if there is a sudden change in wind direction or an emergency obstacle avoidance is required, the ground operator cannot issue commands, posing a significant safety hazard.

[0004] Furthermore, existing technologies typically treat satellite links as a passive "pipeline," failing to fully utilize two key prior pieces of information for UAV inspection missions: ① the flight trajectory is pre-planned; ② satellite ephemeris is publicly available and predictable. If these two points can be utilized to plan communication resources for the entire mission cycle before UAV takeoff and to proactively adjust the UAV's flight strategy based on satellite positions during flight, the reliable control challenges under highly dynamic topologies will be fundamentally solved.

[0005] Therefore, the core technical problem currently facing the industry is: how to combine the predetermined flight path of UAV inspection with satellite ephemeris to achieve continuous and reliable issuance of flight control commands and proactive adaptive management of UAVs under the condition that frequent switching of low-orbit satellites causes intermittent link interruptions. Summary of the Invention

[0006] This invention provides a method for the inspection and control of low-altitude unmanned aerial vehicles (UAVs) using low-Earth orbit satellite communication, comprising: Step S1: Based on the inspection task, obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, calculate the relative position and satellite-to-ground link margin between the UAV and each visible satellite, and generate a spatiotemporal four-dimensional link budget table. Step S2: Based on the spatiotemporal four-dimensional link budget table, the communication area of ​​the mission route is divided into three types of communication areas: stable, weak coverage, and void. Pre-set flight command packets are generated for each void communication area. Step S3: Before the UAV enters the hollow communication area, the pre-set flight command packet is encoded using fountain code and sent to the UAV carrier through dual independent satellite-to-ground links during the multi-satellite co-view window. Step S4: After the UAV enters the hollow communication area and loses contact with the satellite, it automatically calls the preset flight command package to carry out autonomous flight; Step S5: After the UAV flies out of the hollow communication area and reconnects with the satellite, it transmits its flight trajectory back to the ground control center for comparison, then resumes the normal remote control mode and transmits complete inspection data.

[0007] The method for low-altitude UAV inspection and control using low-Earth orbit satellite communication as described above includes the following sub-steps: acquiring the mission route, full-cycle time series, and real-time ephemeris of the low-Earth orbit satellites based on the inspection mission; calculating the relative position and satellite-to-ground link margin between the UAV and each visible satellite; and generating a spatiotemporal four-dimensional link budget table. Step S11: Based on the inspection task, obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, predict the relative position of the UAV and each visible satellite at each moment, and generate a dynamic visible satellite set for the entire mission cycle. Step S12: Calculate the real-time link margin of each satellite's satellite-to-ground link within the dynamic visible satellite set at each time point, form a four-dimensional link margin matrix, and generate a spatiotemporal four-dimensional link budget table by combining the dynamic visible satellite set.

[0008] The method for low-altitude UAV inspection and control using low-orbit satellite communication as described above, wherein, based on a spatiotemporal four-dimensional link budget table, the communication area of ​​the mission route is divided into three types of communication zones: stable, weak coverage, and void. Generating pre-set flight command packets for each void communication zone includes the following sub-steps: Step S21: Based on the spatiotemporal four-dimensional link budget table, define the link margin threshold for three types of communication zones, and divide the full-cycle time series of the task and the corresponding flight path into continuous intervals of stable, weak coverage, and hollow communication zones. Step S22: Obtain the environmental prior parameters of each cavity communication zone and generate a preset flight command package for each cavity communication zone.

[0009] The method for low-altitude UAV inspection and control using low-Earth orbit satellite communication as described above includes the following sub-steps: Before the UAV enters a void communication zone, a pre-set flight command packet is encoded using fountain codes. During a multi-satellite shared-view window, the command is transmitted to the UAV's payload via dual independent satellite-to-ground links. Step S31: For each void communication area, determine the pre-send window period, and based on the spatiotemporal four-dimensional link budget table, select the multi-satellite co-view window period during the pre-send window period to determine the satellite nodes of the dual independent satellite-ground link; Step S32: Based on the duration of the multi-star co-view window and the spatiotemporal four-dimensional link budget table, after optimizing the coding degree distribution of the fountain code, the preset flight command packet is encoded with the fountain code to generate a coding packet sequence. Step S33: During the multi-satellite co-view window, the encoded packet sequence is transmitted to the UAV in parallel with spatiotemporal diversity through two independent satellite-to-ground links. The UAV verifies and decrypts the packet and caches it in its memory.

[0010] The method for low-altitude UAV inspection and control using low-Earth orbit satellite communication as described above, wherein after the UAV enters a void communication zone and loses contact with the satellite, it automatically invokes a pre-set flight command package to conduct autonomous flight, includes the following sub-steps: Step S41: The UAV terminal collects its own flight parameters in real time and compares them with the spatiotemporal boundary of the void communication zone. When it is determined that it has entered the void communication zone, it automatically calls the cached preset flight command package and executes flight control according to its predetermined command. Step S42: Based on the environmental parameters collected by the airborne sensors, call the preset commands in the preset flight command package to correct the flight control parameters and collect inspection data.

[0011] The method for low-altitude UAV inspection and control using low-orbit satellite communication as described above includes the following sub-steps: After the UAV flies out of the communication void and reconnects with the satellite, it transmits its flight trajectory back to the ground control center for comparison. Then, it resumes the normal remote control mode and retransmits complete inspection data. Step S51: The UAV carrier detects the satellite link status in real time. After determining that it has flown out of the hollow communication zone, it reconnects with the satellite and transmits the flight trajectory data within the hollow communication zone back to the ground control center. Step S52: The ground control center will perform a spatiotemporal consistency comparison and verification between the flight trajectory data and the mission route. After the verification is successful, the complete inspection data will be retransmitted according to priority.

[0012] This invention also provides a system for the inspection and control of low-altitude unmanned aerial vehicles (UAVs) using low-orbit satellite communication, comprising: The spatiotemporal four-dimensional link budget table generation module obtains the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites based on the inspection mission, calculates the relative position and satellite-to-ground link margin between the UAV and each visible satellite, and generates a spatiotemporal four-dimensional link budget table. The command packet generation module, based on the spatiotemporal four-dimensional link budget table, divides the communication area of ​​the mission route into three types of communication areas: stable, weak coverage, and void, and generates pre-set flight command packets for each void communication area. The command delivery module encodes the pre-set flight command packet using fountain code before the UAV enters the hollow communication zone, and then sends it to the UAV carrier via dual independent satellite-to-ground links during the multi-satellite co-view window. The command packet invocation module automatically invokes preset flight command packets to conduct autonomous flight after the UAV enters a hollow communication zone and loses contact with the satellite. The data backhaul module transmits the drone's flight trajectory back to the ground control center after it flies out of the communication void and reconnects with the satellite. After comparison, it resumes the normal remote control mode and transmits complete inspection data.

[0013] As described above, a system for low-altitude UAV inspection and control using low-Earth orbit satellite communication includes a spatiotemporal four-dimensional link budget table generation module, which specifically comprises: The visual satellite set generation submodule, based on the inspection mission to obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, predicts the relative position of the UAV and each visual satellite at each moment, and generates a dynamic visual satellite set for the entire mission cycle. The link margin calculation submodule calculates the real-time link margin of each satellite's satellite-to-ground link within the dynamically visible satellite set at each time point, forming a four-dimensional link margin matrix. Combined with the dynamically visible satellite set, it generates a spatiotemporal four-dimensional link budget table.

[0014] The system for low-altitude UAV inspection and control using low-Earth orbit satellite communication as described above includes a pre-set flight command packet generation module, specifically comprising: The communication zone division submodule, based on the spatiotemporal four-dimensional link budget table, defines the link margin thresholds for three types of communication zones, and divides the full-cycle time series of the task and the corresponding flight path into continuous intervals of stable, weak coverage, and hollow communication zones. The preset flight command package generation submodule obtains the environmental prior parameters of each cavity communication zone and generates a preset flight command package for each cavity communication zone.

[0015] As described above, a system for low-altitude UAV inspection and control using low-Earth orbit satellite communication includes, in part, a command issuance module comprising: The multi-satellite co-viewing window screening submodule determines the pre-send window for each void communication area, and screens the multi-satellite co-viewing window based on the spatiotemporal four-dimensional link budget table to determine the satellite nodes of the dual independent satellite-to-ground links. The fountain code encoding submodule, based on the duration of the multi-star common viewing window and the spatiotemporal four-dimensional link budget table, optimizes the encoding degree distribution of the fountain code, encodes the preset flight command packets with fountain codes, and generates an encoding packet sequence. The encoded packet sequence distribution submodule transmits the encoded packet sequence to the UAV in a time-space diversity parallel manner through two independent satellite-to-ground links during the multi-satellite co-view window. The UAV verifies, decrypts, and caches the encoded packet sequence in its memory.

[0016] As described above, a system for low-altitude UAV inspection and control using low-Earth orbit satellite communication includes, in part, a command packet invocation module, which specifically comprises: In the cavity entry determination submodule, the UAV's onboard unit collects its own flight parameters in real time and compares them with the spatiotemporal boundary of the cavity communication zone. When it is determined that the UAV has entered the cavity communication zone, it automatically calls the cached preset flight command package and executes flight control according to its predetermined instructions. The flight control parameter correction and data acquisition submodule corrects flight control parameters based on environmental parameters collected by airborne sensors, calls preset commands in the preset flight command package to correct the parameters, and collects inspection data.

[0017] As described above, a low-altitude UAV inspection and control system using low-Earth orbit satellite communication includes a data transmission module, specifically comprising: The flight trajectory data feedback submodule detects the satellite link status in real time on the UAV terminal. After determining that it has flown out of the hollow communication zone, it reconnects with the satellite and sends the flight trajectory data within the hollow communication zone back to the ground control center. In the inspection data feedback submodule, the ground control center performs a spatiotemporal consistency comparison and verification between the flight trajectory data and the mission route. After the verification is passed, the complete inspection data is retransmitted according to priority.

[0018] The beneficial effects achieved by this invention are as follows: This invention can fundamentally avoid the risk of drone disconnection and loss of control caused by communication gaps resulting from dynamic coverage of low-Earth orbit satellites, significantly improving the inherent safety of drone inspection operations in remote areas. This invention is also widely applicable to long-distance drone inspection scenarios in remote areas across multiple fields such as power, oil and gas, forestry, and geological exploration, greatly expanding the applicability of low-Earth orbit satellite-enabled drone inspections and significantly improving the task completion rate and overall operational efficiency of inspection operations. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a flowchart of a method for low-altitude UAV inspection and control using low-orbit satellite communication provided in Embodiment 1 of this application; Figure 2 This is a schematic diagram of a low-altitude UAV inspection and control system based on low-orbit satellite communication, provided in Embodiment 2 of this application. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1

[0023] like Figure 1 As shown, Embodiment 1 of this application provides a method for the inspection and control of low-altitude unmanned aerial vehicles (UAVs) using low-orbit satellite communication. The method includes the following steps: Step S1: Based on the inspection task, obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, calculate the relative position and satellite-to-ground link margin between the UAV and each visible satellite, and generate a spatiotemporal four-dimensional link budget table. Furthermore, based on the inspection mission's acquired flight path, full-cycle time series, and real-time ephemeris of low-orbit satellites, the relative positions of the UAV and each visible satellite, as well as the satellite-to-ground link margins, are calculated to generate a spatiotemporal four-dimensional link budget table, including the following sub-steps: Step S11: Based on the inspection task, obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, predict the relative position of the UAV and each visible satellite at each moment, and generate a dynamic visible satellite set for the entire mission cycle. Specifically, from the inspection missions of low-altitude UAVs, the predetermined mission routes, full-cycle time series, and real-time ephemeris of low-orbit satellites are extracted. All spatial coordinates are unified to the geocentric inertial coordinate system, and time is unified to the UTC reference. For each moment within the full-cycle time series, a visual satellite prediction algorithm is used. Calculate the set of visible satellites for the UAV at each time point, where, for The set of visible satellites for the drone is defined by the satellite numbers that meet the visibility criteria. For satellite indexing, , For the total number of satellites, for Time of the first The pitch angle of the satellite relative to the drone, , Pre-planning of routes for drones The spatial position vector at a given time. for Time of the first The spatial position vector of the satellite, This is the lowest visible pitch angle for the airborne satellite terminal. for Time drones and the first The distance between satellites and the ground link. , This represents the maximum effective transmission distance of a low-Earth orbit satellite communication link. It is a full-cycle time series. , For takeoff time, The end of the mission. Indicates any All belong to .

[0024] Step S12: Calculate the real-time link margin of each satellite's satellite-to-ground link within the dynamic visible satellite set at each time point, form a four-dimensional link margin matrix, and generate a spatiotemporal four-dimensional link budget table by combining the dynamic visible satellite set. Specifically, for each satellite in the dynamically visible satellite set at each moment, the spatiotemporal four-dimensional coupling link margin algorithm is used. Calculate the relationship between the drone and the first drone at each time point. The link margin for each visible satellite, where each parameter has been dimensionless. for Time drones and the first Link margin for each visible satellite, This indicates that the link can communicate stably. For the transmission power of the airborne satellite terminal, For the transmit antenna gain, For satellite receiving antenna gain, for Time of the first Free-space propagation loss of a visible satellite, , for Time drones and the first The distance between satellites and the ground link. The carrier center frequency of the satellite-to-ground communication link. The speed of light in a vacuum. , They are respectively The time-corresponding link is based on the atmospheric loss and rain attenuation loss pre-calculated using prior meteorological data of the mission area. The minimum received signal-to-noise ratio required for link communication. To provide dynamic margin for the link to compensate for link fluctuations caused by inter-satellite handover and attitude disturbances; to connect the UAV with the first satellite at each time point. Link margin of a visible satellite The dataset is aggregated to generate a four-dimensional link margin matrix covering the entire mission lifecycle and all flight segments; based on the four-dimensional link margin matrix and the visual satellite set... Generate a spatiotemporal four-dimensional link budget table for the entire task lifecycle, which includes each It corresponds to the UAV's flight path, the set of visible satellites, the satellite-to-ground link margin of each visible satellite, the maximum link margin value, the link availability time, the link packet loss rate, and other core parameters.

[0025] Step S2: Based on the spatiotemporal four-dimensional link budget table, the communication area of ​​the mission route is divided into three types of communication areas: stable, weak coverage, and void. Pre-set flight command packets are generated for each void communication area. Furthermore, based on the spatiotemporal four-dimensional link budget table, the communication area of ​​the mission route is divided into three types of communication zones: stable, weak coverage, and void. The generation of pre-set flight command packets for each void communication zone includes the following sub-steps: Step S21: Based on the spatiotemporal four-dimensional link budget table, define the link margin threshold for three types of communication zones, and divide the full-cycle time series of the task and the corresponding flight path into continuous intervals of stable, weak coverage, and hollow communication zones. Specifically, based on the reliability requirements of flight control commands for UAV inspection, link margin thresholds are defined for three types of communication zones, with the stable communication zone being... The weak coverage communication area is Hollow communication area is ,in, In order to be in Real-time drone visual satellite collection Corresponding satellite-to-ground link margin The maximum value in, To determine the minimum link margin required for stable communication, the time series and corresponding flight paths of the entire mission cycle are divided into continuous intervals based on the link margin thresholds of three types of communication zones. These continuous time-flight intervals are further divided into three types: stable communication zone, weak coverage communication zone, and hollow communication zone. The spatiotemporal boundaries of all hollow communication zones are then calibrated to generate a set of hollow communication zones. , among which, the The spatiotemporal boundary of the hollow communication zone is , For drones to enter the first The moment of a hollow communication zone For the drone to fly out of the first The moment of a hollow communication zone For the first A hollow communication zone entrance trackpoint, For the first A hollow communication zone exit trackpoint.

[0026] Step S22: Obtain the prior environmental parameters of each cavity communication zone and generate a preset flight command packet for each cavity communication zone; Specifically, environmental prior parameters for each hollow communication zone are extracted from the meteorological prior data of the mission area, including but not limited to topography, meteorology, and wind field, to define the spatiotemporal boundaries of each hollow communication zone. The flight path parameters of the UAV in each cavity communication zone and the environmental prior parameters of the corresponding flight segment in each cavity communication zone are spatiotemporally mapped to generate a pre-set flight command package that includes a predetermined flight path, preset wind disturbance compensation, emergency obstacle avoidance logic, and inspection sampling parameters, and is strictly matched with the duration of each cavity communication zone. The pre-set flight command package for each cavity communication zone is subjected to cyclic redundancy verification, encrypted encapsulation, and a cavity communication zone number is added. A unique identifier for binding.

[0027] Step S3: Before the UAV enters the hollow communication area, the pre-set flight command packet is encoded using fountain code and sent to the UAV carrier through dual independent satellite-to-ground links during the multi-satellite co-view window. Furthermore, before the UAV enters the void communication zone, the pre-set flight command packet is encoded using fountain code. During the multi-satellite co-view window, the command is transmitted to the UAV's payload via dual independent satellite-to-ground links, including the following sub-steps: Step S31: For each void communication area, determine the pre-send window period, and based on the spatiotemporal four-dimensional link budget table, select the multi-satellite co-view window period during the pre-send window period to determine the satellite nodes of the dual independent satellite-ground link; Specifically, at the entry time of the spatiotemporal boundary of the cavity communication zone, a preset safety lead time is superimposed and used as a rigid upper limit for the end time of the window period. Based on the data volume of the preset flight command packet corresponding to the target cavity communication zone, the effective transmission rate of the satellite-to-ground link, the encoding and decoding time, and the time required for response confirmation, the minimum duration required for the complete transmission of the preset flight command packet is determined as the minimum requirement for the duration of the window period. Stable communication zones are then selected from the spatiotemporal four-dimensional link budget table, limiting the window period to the range of flight segments with stable communication conditions, and determining the pre-delivery window period for each cavity communication zone. , For the first The earliest start time of the pre-send window for each hollow communication zone. For the first The latest end time of the pre-deployment window for each hollow communication area. For drones to enter the first The timing of each void communication zone; based on the spatiotemporal four-dimensional link budget table, a dual independent link shared-view window determination algorithm is used. Pre-issuance window period Internal screening of multi-star co-viewing window, among which, For the first The dual independent link multi-satellite common viewing window period corresponding to each void communication area For the first A pre-send window for a hollow communication zone. These are two different visible satellites, belonging to... , Two different orbital planes, for A visual satellite array for real-time drones.

[0028] Step S32: Based on the duration of the multi-star co-view window and the spatiotemporal four-dimensional link budget table, after optimizing the coding degree distribution of the fountain code, the preset flight command packet is encoded with the fountain code to generate a coding packet sequence. Specifically, based on the duration of the multi-satellite co-view window and the link packet loss rate in the spatiotemporal four-dimensional link budget table, a fountain bitrate distribution formula adapted to the multi-satellite co-view window is used. The coding degree distribution is optimized, whereby... For the optimized coding degree distribution (code packet selection) (the probability of performing an XOR operation on 1 primitive symbol) For degree value adaptation factor, , For coding degree, The duration of the multi-satellite viewing window. The transmission duration of a single coded symbol. This is the duration fluctuation coefficient. For link packet loss rate, To achieve the maximum coding degree, Based on the optimized coding degree distribution The preset flight command packets are fountain-coded to generate an encoded packet sequence.

[0029] Step S33: During the multi-satellite co-view window, the encoded packet sequence is transmitted to the UAV in a time-space diversity parallel manner through two independent satellite-to-ground links. The UAV verifies and decrypts the packet and caches it in its memory. Specifically, during the multi-satellite co-viewing window Inside, coded packet sequences are transmitted in parallel via two independent space-to-ground links using spatiotemporal diversity. The transmission sequences of the two links are staggered. The UAV receiver receives the coded packets, completes full decoding when a decoding threshold is reached, and sends a reception confirmation message back to the ground control center. The UAV receiver verifies and decrypts the decoded preset flight command packets. After successful verification, it associates them with the corresponding hole communication area number. Spacetime Boundaries The message is bound and cached in the airborne non-volatile memory. If the ground control center does not receive the confirmation message before the end of the pre-send window period, it will be resent during the subsequent window period in the weak coverage area.

[0030] Step S4: After the UAV enters the hollow communication area and loses contact with the satellite, it automatically calls the preset flight command package to carry out autonomous flight; Furthermore, after the drone enters a hollow communication zone and loses contact with the satellite, it automatically invokes a pre-set flight command package to conduct autonomous flight, including the following sub-steps: Step S41: The UAV terminal collects its own flight parameters in real time and compares them with the spatiotemporal boundary of the void communication zone. When it is determined that it has entered the void communication zone, it automatically calls the cached preset flight command package and executes flight control according to its predetermined command. Specifically, the drone's onboard unit collects its own flight position and time information in real time, and compares it with the data of the first... The spatiotemporal boundary of a hollow communication zone A comparison is performed when the flight position collected in real time by the drone is compared with the first... The distance between the entry trackpoints of the three hollow communication zones is less than the position threshold, and when the time information collected by the UAV in real time is consistent with the UAV entering the first... If the time difference between the times of the first hollow communication zone is less than the time threshold, then it is determined that the second hollow communication zone has entered the first hollow communication zone. Within a hollow communication zone, an open-loop autonomous flight mode is initiated. Pre-set flight command packets cached in memory are automatically invoked, and flight control is executed according to the predetermined trajectory sequence within them. Simultaneously, real-time flight status is collected via the onboard inertial measurement unit, global navigation satellite system, and barometric altimeter. An algorithm for tracking error constraints on the open-loop flight trajectory within the hollow communication zone is then used. Minimize the deviation between the actual flight trajectory and the predetermined inspection route, while simultaneously minimizing control variable fluctuations. To optimize the objective function for trajectory tracking, For drones to enter the first The moment of a hollow communication zone For the drone to fly out of the first At any given moment in a hollow communication zone Every moment belongs to , for The actual flight path of the drone at all times. for The scheduled flight path of the drone. To control the weighting coefficients, for The increment of flight control quantities after dimensionless measurement (throttle, yaw, roll, pitch). , To set the maximum allowable trajectory deviation based on the inspection accuracy requirements.

[0031] Step S42: Based on the environmental parameters collected by the airborne sensors, call the preset commands in the preset flight command package to correct the flight control parameters and collect inspection data; Specifically, based on the wind field and terrain data collected by airborne sensors within the cavity communication area, the flight control parameters are corrected in real time according to the wind disturbance compensation and emergency obstacle avoidance logic preset in the pre-set flight command package to cope with sudden environmental disturbances; when an extreme fault occurs, the preset emergency landing or hovering command is executed immediately, and all fault data and flight data are cached at the same time; during flight in the cavity communication area, the UAV performs inspection data collection according to the sampling parameters in the command package, and caches all inspection data and flight status data in real time to the airborne memory, and transmits them back after reconnection.

[0032] Step S5: After the UAV flies out of the hollow communication area and reconnects with the satellite, its flight trajectory is transmitted back to the ground control center for comparison. Then, the normal remote control mode is restored and the complete inspection data is transmitted. Furthermore, after the drone flies out of the communication void and reconnects with the satellite, it transmits its flight trajectory back to the ground control center for comparison. Then, it resumes normal remote control mode and retransmits complete inspection data, including the following sub-steps: Step S51: The UAV carrier detects the satellite link status in real time. After determining that it has flown out of the hollow communication zone, it reconnects with the satellite and transmits the flight trajectory data within the hollow communication zone back to the ground control center. Specifically, the UAV's onboard unit monitors the satellite link status in real time. When the link margin is detected to be greater than zero, it determines that it has flown out of the void communication zone, reconnects with the satellite, and synchronizes with the ground control center in terms of time and space reference. The UAV then transmits the full-cycle flight trajectory data within the void communication zone back to the ground control center.

[0033] Step S52: The ground control center will compare and verify the spatiotemporal consistency of the flight trajectory data with the mission route. After the verification is successful, the complete inspection data will be retransmitted according to priority. Specifically, based on the four-dimensional time and space benchmark, the ground control center performs a full-cycle trajectory consistency comparison and verification between the actual flight trajectory and the predetermined inspection route. When the verification shows no deviation, the ground control center immediately resumes the conventional remote control mode for the UAV and continues to execute subsequent inspection tasks. When the verification fails, the ground control center immediately issues a trajectory correction command to control the UAV to return to the predetermined route. At the same time, it dynamically updates the four-dimensional link budget table and preset command packets for subsequent flight segments. Based on the real-time bandwidth and link margin of the current satellite link, combined with the data volume and transmission urgency of various types of data in the cavity communication area inspection data, a priority-based retransmission strategy for the cavity communication area inspection data is formulated. The cavity communication area inspection data is dynamically and adaptively transmitted back to the ground control center in sequence according to the priority-based retransmission strategy.

[0034] Example 2

[0035] like Figure 2As shown, Embodiment 2 of this application provides a system for the inspection and control of low-altitude unmanned aerial vehicles (UAVs) using low-orbit satellite communication, comprising: The spatiotemporal four-dimensional link budget table generation module 21, based on the inspection task to obtain the task route, full-cycle time series and real-time ephemeris of low-orbit satellites, calculates the relative position and satellite-to-ground link margin between the UAV and each visible satellite, and generates a spatiotemporal four-dimensional link budget table. Furthermore, the spatiotemporal four-dimensional link budget table generation module 21 includes the following sub-modules: The visual satellite set generation submodule, based on the inspection mission to obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, predicts the relative position of the UAV and each visual satellite at each moment, and generates a dynamic visual satellite set for the entire mission cycle. The link margin calculation submodule calculates the real-time link margin of each satellite's satellite-to-ground link within the dynamically visible satellite set at each time, forming a four-dimensional link margin matrix. Combined with the dynamically visible satellite set, it generates a spatiotemporal four-dimensional link budget table. The instruction packet generation module 22, based on the spatiotemporal four-dimensional link budget table, divides the communication area of ​​the mission route into three types of communication areas: stable, weak coverage, and void, and generates pre-set flight instruction packets for each void communication area. Furthermore, the pre-set flight command package generation module 22 includes the following sub-modules: The communication zone division submodule, based on the spatiotemporal four-dimensional link budget table, defines the link margin thresholds for three types of communication zones, and divides the full-cycle time series of the task and the corresponding flight path into continuous intervals of stable, weak coverage, and hollow communication zones. The pre-set flight command packet generation submodule obtains the environmental prior parameters of each cavity communication zone and generates a pre-set flight command packet for each cavity communication zone. Before the UAV enters the void communication zone, the command issuing module 23 encodes the pre-set flight command packet using fountain code and issues it to the UAV carrier via dual independent satellite-to-ground links during the multi-satellite co-view window. Furthermore, the instruction issuing module 23 includes the following sub-modules: The multi-satellite co-viewing window screening submodule determines the pre-send window for each void communication area, and screens the multi-satellite co-viewing window based on the spatiotemporal four-dimensional link budget table to determine the satellite nodes of the dual independent satellite-to-ground links. The fountain code encoding submodule, based on the duration of the multi-star common viewing window and the spatiotemporal four-dimensional link budget table, optimizes the encoding degree distribution of the fountain code, encodes the preset flight command packets with fountain codes, and generates an encoding packet sequence. The encoding packet sequence distribution submodule transmits the encoding packet sequence to the UAV in a time-space diversity parallel manner through two independent satellite-to-ground links during the multi-satellite co-view window. The UAV verifies, decrypts, and caches the encoded packet sequence in its memory. Command packet calling module 24: After the UAV enters the hollow communication area and loses contact with the satellite, it automatically calls the preset flight command packet to carry out autonomous flight; Furthermore, the instruction package invocation module 24 includes the following sub-modules: In the cavity entry determination submodule, the UAV's onboard unit collects its own flight parameters in real time and compares them with the spatiotemporal boundary of the cavity communication zone. When it is determined that the UAV has entered the cavity communication zone, it automatically calls the cached preset flight command package and executes flight control according to its predetermined instructions. The flight control parameter correction and data acquisition submodule corrects the flight control parameters based on the environmental parameters collected by the airborne sensors, calls the preset commands in the preset flight command package to correct the flight control parameters, and collects inspection data. Data back transmission module 25: After the UAV flies out of the hollow communication area and reconnects with the satellite, it transmits its flight trajectory back to the ground control center for comparison, and then resumes the normal remote control mode and retransmits the complete inspection data. Furthermore, the data return module 25 includes the following sub-modules: The flight trajectory data feedback submodule detects the satellite link status in real time on the UAV terminal. After determining that it has flown out of the hollow communication zone, it reconnects with the satellite and sends the flight trajectory data within the hollow communication zone back to the ground control center. In the inspection data feedback submodule, the ground control center compares and verifies the spatiotemporal consistency of the flight trajectory data with the mission route. After the verification is passed, the complete inspection data is retransmitted according to priority. Corresponding to the above embodiments, the present invention provides a computer storage medium, including: at least one memory and at least one processor; The memory is used to store one or more program instructions; A processor for running one or more program instructions to execute a method for the inspection and control of low-altitude unmanned aerial vehicles using low-Earth orbit satellite communication.

[0036] Corresponding to the above embodiments, this embodiment of the invention provides a computer-readable storage medium containing one or more program instructions, which are used by a processor to provide a method for the inspection and control of low-altitude unmanned aerial vehicles using low-orbit satellite communication.

[0037] The embodiments disclosed in this invention provide a computer-readable storage medium storing computer program instructions. When the computer program instructions are executed on a computer, the computer performs the above-described method for low-altitude UAV inspection and control via low-orbit satellite communication.

[0038] In this embodiment of the invention, the processor can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0039] The various methods, steps, and logic diagrams disclosed in the embodiments of this invention can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The processor reads information from the storage medium and, in conjunction with its hardware, completes the steps of the above methods.

[0040] The storage medium can be memory, such as volatile memory or non-volatile memory, or may include both volatile and non-volatile memory.

[0041] Among them, non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory.

[0042] Volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (Synchlink DRAM, SLDRAM), and direct memory bus RAM (DRRAM).

[0043] The storage media described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memory.

[0044] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this invention can be implemented using a combination of hardware and software. When applied as software, the corresponding functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transmission of computer programs from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0045] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for low-altitude unmanned aerial vehicle inspection and control of low-orbit satellite communication, characterized in that, include: Step S1: Based on the inspection task, obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, calculate the relative position and satellite-to-ground link margin between the UAV and each visible satellite, and generate a spatiotemporal four-dimensional link budget table. Step S2: Based on the spatiotemporal four-dimensional link budget table, the communication area of ​​the mission route is divided into three types of communication areas: stable, weak coverage, and void. Pre-set flight command packets are generated for each void communication area. Step S3: Before the UAV enters the hollow communication area, the pre-set flight command packet is encoded using fountain code and sent to the UAV carrier through dual independent satellite-to-ground links during the multi-satellite co-view window. Step S4: After the UAV enters the hollow communication area and loses contact with the satellite, it automatically calls the preset flight command package to carry out autonomous flight; Step S5: After the UAV flies out of the hollow communication area and reconnects with the satellite, it transmits its flight trajectory back to the ground control center for comparison, then resumes the normal remote control mode and transmits complete inspection data.

2. The method for low-altitude UAV inspection and control using low-orbit satellite communication as described in claim 1, characterized in that, Based on the inspection mission, the mission route, full-cycle time series, and real-time ephemeris of low-orbit satellites are obtained. The relative positions of the UAV and each visible satellite and the satellite-to-ground link margin are calculated, and a spatiotemporal four-dimensional link budget table is generated, including the following sub-steps: Step S11: Based on the inspection task, obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, predict the relative position of the UAV and each visible satellite at each moment, and generate a dynamic visible satellite set for the entire mission cycle. Step S12: Calculate the real-time link margin of each satellite's satellite-to-ground link within the dynamic visible satellite set at each time point, form a four-dimensional link margin matrix, and generate a spatiotemporal four-dimensional link budget table by combining the dynamic visible satellite set.

3. The method for low-altitude UAV inspection and control using low-orbit satellite communication as described in claim 1, characterized in that, Based on the spatiotemporal four-dimensional link budget table, the communication area of ​​the mission route is divided into three types of communication areas: stable, weak coverage, and void. The generation of pre-set flight command packets for each void communication area includes the following sub-steps: Step S21: Based on the spatiotemporal four-dimensional link budget table, define the link margin threshold for three types of communication zones, and divide the full-cycle time series of the task and the corresponding flight path into continuous intervals of stable, weak coverage, and hollow communication zones. Step S22: Obtain the environmental prior parameters of each cavity communication zone and generate a preset flight command package for each cavity communication zone.

4. The method for low-altitude UAV inspection and control using low-orbit satellite communication as described in claim 1, characterized in that, Before the UAV enters the void communication zone, the pre-set flight command packet is encoded using fountain code. During the multi-satellite co-view window, the command is sent to the UAV's payload via dual independent satellite-to-ground links, including the following sub-steps: Step S31: For each void communication area, determine the pre-send window period, and based on the spatiotemporal four-dimensional link budget table, select the multi-satellite co-view window period during the pre-send window period to determine the satellite nodes of the dual independent satellite-ground link; Step S32: Based on the duration of the multi-star co-view window and the spatiotemporal four-dimensional link budget table, after optimizing the coding degree distribution of the fountain code, the preset flight command packet is encoded with the fountain code to generate a coding packet sequence. Step S33: During the multi-satellite co-view window, the encoded packet sequence is transmitted to the UAV in parallel with spatiotemporal diversity through two independent satellite-to-ground links. The UAV verifies and decrypts the packet and caches it in its memory.

5. The method for low-altitude UAV inspection and control using low-orbit satellite communication as described in claim 1, characterized in that, After the drone enters a hollow communication zone and loses contact with the satellite, it automatically invokes a pre-set flight command package to conduct autonomous flight, including the following sub-steps: Step S41: The UAV terminal collects its own flight parameters in real time and compares them with the spatiotemporal boundary of the void communication zone. When it is determined that it has entered the void communication zone, it automatically calls the cached preset flight command package and executes flight control according to its predetermined command. Step S42: Based on the environmental parameters collected by the airborne sensors, call the preset commands in the preset flight command package to correct the flight control parameters and collect inspection data.

6. A system for low-altitude unmanned aerial vehicle (UAV) inspection and control via low-orbit satellite communication, characterized in that, include: The spatiotemporal four-dimensional link budget table generation module obtains the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites based on the inspection mission, calculates the relative position and satellite-to-ground link margin between the UAV and each visible satellite, and generates a spatiotemporal four-dimensional link budget table. The command packet generation module, based on the spatiotemporal four-dimensional link budget table, divides the communication area of ​​the mission route into three types of communication areas: stable, weak coverage, and void, and generates pre-set flight command packets for each void communication area. The command delivery module encodes the pre-set flight command packet using fountain code before the UAV enters the hollow communication zone, and then sends it to the UAV carrier via dual independent satellite-to-ground links during the multi-satellite co-view window. The command packet invocation module automatically invokes preset flight command packets to conduct autonomous flight after the UAV enters a hollow communication zone and loses contact with the satellite. The data backhaul module transmits the drone's flight trajectory back to the ground control center after it flies out of the communication void and reconnects with the satellite. After comparison, it resumes the normal remote control mode and transmits complete inspection data.

7. A system for low-altitude UAV inspection and control via low-orbit satellite communication as described in claim 6, characterized in that, The spatiotemporal four-dimensional link budget table generation module specifically includes: The visual satellite set generation submodule, based on the inspection mission to obtain the mission route, full-cycle time series and real-time ephemeris of low-orbit satellites, predicts the relative position of the UAV and each visual satellite at each moment, and generates a dynamic visual satellite set for the entire mission cycle. The link margin calculation submodule calculates the real-time link margin of each satellite's satellite-to-ground link within the dynamically visible satellite set at each time point, forming a four-dimensional link margin matrix. Combined with the dynamically visible satellite set, it generates a spatiotemporal four-dimensional link budget table.

8. A system for low-altitude UAV inspection and control via low-orbit satellite communication as described in claim 6, characterized in that, The pre-configured flight command package generation module specifically includes: The communication zone division submodule, based on the spatiotemporal four-dimensional link budget table, defines the link margin thresholds for three types of communication zones, and divides the full-cycle time series of the task and the corresponding flight path into continuous intervals of stable, weak coverage, and hollow communication zones. The preset flight command package generation submodule obtains the environmental prior parameters of each cavity communication zone and generates a preset flight command package for each cavity communication zone.

9. A system for low-altitude UAV inspection and control via low-orbit satellite communication as described in claim 6, characterized in that, The instruction issuance module specifically includes: The multi-satellite co-viewing window screening submodule determines the pre-send window for each void communication area, and screens the multi-satellite co-viewing window based on the spatiotemporal four-dimensional link budget table to determine the satellite nodes of the dual independent satellite-to-ground links. The fountain code encoding submodule, based on the duration of the multi-star common viewing window and the spatiotemporal four-dimensional link budget table, optimizes the encoding degree distribution of the fountain code, encodes the preset flight command packets with fountain codes, and generates an encoding packet sequence. The encoded packet sequence distribution submodule transmits the encoded packet sequence to the UAV in a time-space diversity parallel manner through two independent satellite-to-ground links during the multi-satellite co-view window. The UAV verifies, decrypts, and caches the encoded packet sequence in its memory.

10. A system for low-altitude UAV inspection and control via low-orbit satellite communication as described in claim 6, characterized in that, The instruction package calls the module, specifically including: In the cavity entry determination submodule, the UAV's onboard unit collects its own flight parameters in real time and compares them with the spatiotemporal boundary of the cavity communication zone. When it is determined that the UAV has entered the cavity communication zone, it automatically calls the cached preset flight command package and executes flight control according to its predetermined instructions. The flight control parameter correction and data acquisition submodule corrects flight control parameters based on environmental parameters collected by airborne sensors, calls preset commands in the preset flight command package to correct the parameters, and collects inspection data.

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