Low-altitude unmanned aerial vehicle group double-frequency link emergency networking method and system

Abstract

The invention discloses a low-altitude unmanned aerial vehicle group double-frequency link emergency networking method and system, and the method comprises the steps: constructing a low-frequency control link of low-altitude unmanned aerial vehicles, and enabling the low-frequency control link to adopt a full-distributed control link networking mode; secondly, network control data are shared through the low-frequency control link, global information of the control link is obtained, and the global information comprises unmanned aerial vehicle positioning information, a physical environment and communication resources; then, according to the global information, constructing a high-frequency data link, and performing data transmission through the high-frequency data link; and finally, based on the low-frequency control link and the high-frequency data link, constructing a double-frequency link emergency network by adopting a high-low frequency combination mode. According to the method, a more stable and more reliable control network can be formed, more timely control information support is provided for construction of a high-frequency data link, and the problems of data retransmission and the like under the high-dynamic topology of the unmanned aerial vehicle are better solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of data transmission of low-altitude unmanned aerial vehicle swarms, and in particular relates to a dual-frequency link emergency networking method and system for low-altitude unmanned aerial vehicle swarms. Background Art

[0002] In the field of urban emergency rescue, drones, as an emerging low-altitude aircraft, have been widely recognized and applied to a variety of emergency situations, including natural disaster management, disaster accident rescue, and social security management. These aircraft provide important support for rescue operations by leveraging their full-area deployment capabilities, all-terrain mobility, and full-space three-dimensional coverage. In particular, drones have demonstrated their unique advantages in aerial fire monitoring and supervision of large public areas. They can carry high-definition cameras and other multi-mode sensors to build an ad hoc network to quickly collect and transmit rescue information, thereby greatly expanding the aerial dimension of urban emergency rescue and effectively improving rescue efficiency. This modular and programmable aircraft has become an indispensable part of low-altitude rescue operations.

[0003] Although drones play an important role in urban emergency rescue, existing technologies still face a series of challenges in practical applications. First, the high mobility of drones and the complex communication environment of emergency scenarios lead to frequent changes in the network topology, which makes the traditional single-band link easy to disconnect, resulting in frequent retransmission of data transmission, seriously affecting the connectivity and stability of the air network. Secondly, the flight control and networking control information of drones and the emergency scenario situation data are mixed and transmitted on the same link, which not only increases the complexity of the channel time division multiplexing allocation mechanism, but also brings additional signaling expenses. In addition, different transmission requirements of different types of data share spectrum resources on the same link, resulting in a waste of spectrum resources. More seriously, the disconnection of the link will cause the control data to be unable to interact in time, and the time-varying characteristics of the network topology cannot be effectively regulated, which not only reduces the rescue efficiency, but also increases the risk of drone damage. Summary of the invention

[0004] In order to solve the above technical problems, taking into account the differences in multi-source heterogeneous data communication requirements and the high dynamics of the UAV network topology, the present invention designs a UAV communication network topology based on a dual-link architecture, which adopts a combination of high and low frequencies to transmit control information and data information respectively, and builds an efficient and stable two-layer transmission network to ensure the basic control information interaction of the UAV, and solve the stable flow of multimedia data such as audio and video under highly dynamic topology.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a dual-frequency link emergency networking method for a low-altitude UAV group, comprising:

[0006] Constructing a low-frequency control link for a low-altitude UAV, wherein the low-frequency control link adopts a fully distributed control link networking mode;

[0007] Sharing network control data through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources;

[0008] constructing a high-frequency data link according to the global information, and transmitting data through the high-frequency data link;

[0009] Based on the low-frequency control link and the high-frequency data link, a dual-frequency link emergency network is built by combining high and low frequencies.

[0010] Preferably, constructing a low-frequency control link for a low-altitude UAV includes:

[0011] Obtain the self-information of each drone broadcast at maximum power, interact the self-information with the signaling information, and obtain the information of surrounding drones; wherein the signaling information is the control information exchanged between drones;

[0012] Based on the information of surrounding drones, the links between drones are paired and low-frequency control links for low-altitude drones are constructed.

[0013] Preferably, the low-frequency control link adopts a networking module supporting the Wifi Halow protocol, and the frequency band is 840 MHz.

[0014] Preferably, building a high frequency data link includes:

[0015] establishing an initial high frequency data link according to the global information;

[0016] The difference between the network composed of the drones communicating at maximum power and the initial high-frequency data link is evaluated to obtain an optional link set;

[0017] In each round, a link providing maximum utility is searched from the optional link set, wherein the link belongs to the optional link set;

[0018] The link is deleted from the optional link set until the optional link set is an empty set.

[0019] Preferably, the construction method also includes an urban low-altitude channel model based on probabilistic line-of-sight wireless transmission, comprehensively considering the impact of building obstruction between drones on signal propagation, and deriving the average path loss of direct communication between drones.

[0020] Preferably, the construction method also includes a process of optimizing the emergency networking of the dual-frequency link:

[0021] Select different transmission carrier frequencies according to the transmission requirements of different types of information of drones;

[0022] The transmission power is adjusted according to the actual environment of each drone and the distance between nodes.

[0023] In a second aspect, the present invention also provides a dual-frequency link emergency networking system for a low-altitude UAV group, comprising:

[0024] The first link building module is used to build a low-frequency control link of the low-altitude UAV, wherein the low-frequency control link adopts a fully distributed control link networking mode;

[0025] An information acquisition module, used to share network control data through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources;

[0026] A second link building module, used to build a high-frequency data link according to the global information, and perform data transmission through the high-frequency data link;

[0027] The dual-frequency link emergency networking construction module is used to build a dual-frequency link emergency networking based on the low-frequency control link and the high-frequency data link by combining high and low frequencies.

[0028] In a third aspect, the present invention further discloses a computer device, comprising a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the first aspect.

[0029] In a fourth aspect, the present invention further discloses a computer-readable storage medium having a computer program stored thereon, which implements the steps of the method described in the first aspect when executed by a processor.

[0030] In a fifth aspect, the present invention further discloses a computer program product, including a computer program, which implements the steps of the method described in the first aspect when executed by a processor.

[0031] Compared with the prior art, the present invention has the following advantages and technical effects:

[0032] The present invention provides a dual-frequency link emergency networking method for a low-altitude UAV group. First, a low-frequency control link of the low-altitude UAV is constructed, wherein the low-frequency control link adopts a fully distributed control link networking mode; secondly, network control data is shared through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources; then, a high-frequency data link is constructed according to the global information, and data is transmitted through the high-frequency data link; finally, based on the low-frequency control link and the high-frequency data link, a dual-frequency link emergency networking is constructed by combining high and low frequencies.

[0033] The present invention designs a dual-link emergency networking architecture in which a low-frequency control link is separated from a high-frequency data link. By preferentially constructing a low-frequency control link for low-altitude UAVs, a long-distance network link is established while meeting the high penetration of emergency low-altitude scene signals, thereby forming a more stable and reliable control network, realizing larger-scale network control data sharing, and providing a more efficient networking solution for the construction of high-frequency data links. Under the condition of global information intercommunication, the present invention constructs a stable data transmission link through the information of the control link and according to the physical positions and spectrum bandwidth resources of different UAVs, thereby ensuring high-speed and high-real-time data transmission requirements such as video, and better solving problems such as data retransmission under high dynamic topology of UAVs. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] Figure 1 A scene diagram of a dual-link unmanned aerial vehicle self-organizing network according to an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of a low-frequency control link network according to an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of an initial high-frequency data link network according to an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of an optimized high-frequency data link network according to an embodiment of the present invention;

[0039] Figure 5 The figure is a schematic diagram of the change of average link delay during the link establishment process of an embodiment of the present invention. DETAILED DESCRIPTION

[0040] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0042] First, the technical terms involved in the following embodiments are explained.

[0043] (1) The control link refers to the signal transmission link used to control the flight of the drone. The general frequency band for transmitting control information is 840.5MHz-845MHz. Data information (including images, videos, etc.) is generally transmitted in the 2.4GHz / 5GHz frequency band with a larger bandwidth. The control link is the most basic link for drones. Flight control signals and remote control signals are transmitted through this link. The joystick of the remote control can be used to control the drone's up and down flight, left and right steering, pitch and other movements.

[0044] Working principle of the control link: The main function of the control link is to transmit flight control signals and remote control signals through radio frequency signals, so that the drone can respond to the operation of the remote control. Specifically, the control link transmits the remote control's instructions to the drone through 840.5MHz-845MHz radio frequency signals, and the drone performs corresponding actions according to the received instructions.

[0045] Application scenarios of control link: The control link is mainly used for the flight control of the UAV to ensure that the UAV can operate according to the operator's instructions. Since the communication radius of the control link is short (generally within a few thousand meters), the UAV needs to be operated within a certain range to ensure stable signal transmission and safe flight of the UAV.

[0046] (2) Dual-frequency link means that the same device has two independent communication radio frequency circuits, both of which can realize communication and networking. These two circuits use different frequency bands, one high (2.4GHz) and one low (840MHz), to form networks, thus obtaining two communication networks with different frequency bands. This embodiment uses two frequency bands to transmit different information at the same time (low frequency transmits control information, and high frequency transmits data information).

[0047] The working principle of dual-band link is based on the fact that the router or wireless device uses two frequency bands at the same time, 2.4GHz and 840MHz. These two frequency bands have their own advantages and disadvantages:

[0048] 840MHz band: has a wide coverage range, but is susceptible to interference from other wireless devices.

[0049] 2.4GHz frequency band: fast transmission speed, strong anti-interference ability, but small coverage range.

[0050] Application scenarios of dual-band links: In actual use, dual-band links can automatically switch frequency bands based on factors such as the distance of the device and Internet access needs to provide the best wireless experience. For example, when the device is far away from the router, it may automatically switch to the 2.4GHz band to ensure signal strength; when high-speed transmission is required, it will switch to the 5GHz band.

[0051] The difference between dual-band links and other technologies: Compared with single-band links, dual-band links provide higher flexibility and better user experience. Single-band links can only use one frequency band, while dual-band links have two independent and simultaneously working links, providing better network performance and stability.

[0052] (3) Line of Sight (LOS) wireless transmission refers to the situation where the transmitting antenna and the receiving antenna can "see" each other when transmitting signals. This transmission method requires that there are no obstacles between the transmitting antenna and the receiving antenna, or the impact of the obstacles on the signal can be ignored.

[0053] Line-of-sight wireless transmission is mainly divided into the following categories:

[0054] Complete line-of-sight transmission (Complete LOS): There are no obstacles between the transmitting antenna and the receiving antenna that affect signal propagation, and the signal can be fully transmitted.

[0055] Near LOS (nLOS): There are some obstacles between the transmitting antenna and the receiving antenna, but these obstacles have little impact on the signal, and the signal can be partially transmitted.

[0056] Non-line-of-sight transmission (NLOS): The distance between the transmitting antenna and the receiving antenna is completely blocked by obstacles, and the signal cannot be transmitted directly.

[0057] Application scenarios of line-of-sight wireless transmission: Line-of-sight wireless transmission is widely used in various communication systems. Especially when building a WiFi network connection, it is necessary to determine the type of line-of-sight wireless transmission according to the actual situation and select the corresponding wireless installation system. In addition, line-of-sight transmission also has important applications in radio wave propagation, especially in the propagation of radio signals in the VHF and UHF segments. These signals basically propagate in a straight line, and the propagation distance is generally within tens to hundreds of kilometers.

[0058] Advantages of line-of-sight wireless transmission:

[0059] Stable signal: Since there are no obstacles, the signal propagation is stable and the attenuation is small.

[0060] Fast transmission speed: Since it is a straight-line propagation, the signal propagation speed is fast.

[0061] Embodiment 1

[0062] This embodiment provides a dual-frequency link emergency networking method for a low-altitude drone group, including:

[0063] Constructing a low-frequency control link for a low-altitude UAV, wherein the low-frequency control link adopts a fully distributed control link networking mode;

[0064] Sharing network control data through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources;

[0065] constructing a high-frequency data link according to the global information, and transmitting data through the high-frequency data link;

[0066] Based on the low-frequency control link and the high-frequency data link, a dual-frequency link emergency network is built by combining high and low frequencies.

[0067] Specifically, this embodiment provides an architecture example for separating control information from data information. The low-frequency control link networking adopts a networking module that supports the Wifi Halow protocol, and the frequency band is selected as 840Mhz. With the characteristics of large connection (supporting up to 8191 nodes), long distance (single AP has a maximum coverage of 1Km, and supports Relay AP), high reliability, low power consumption, good security (supports 802.11 encryption standards), etc., this protocol perfectly meets the control data transmission requirements and efficiently realizes the rapid interaction of lower-level control data. The high-frequency data link networking equipment adopts a drone self-organized network radio station, and the frequency band is selected as 2.4Ghz. The global information such as drone positioning information, physical environment, and communication resources obtained through the control link is used to build a stable high-frequency data link by adjusting its own transmission power, so as to efficiently realize the circulation of collected data between drones and avoid repeated data collection.

[0068] As an additional implementation method, a multi-UAV network topology model based on a dual-link architecture is shown in Figure 1 As shown. Define the drone collection as V is the total number of drones. The low-frequency control link is the control information transmission layer, which is used to transmit short-packet high-real-time information such as drone location information, signal perception information, and movement trajectory information; the high-frequency data link is the data transmission layer, which is used to transmit long-packet high-throughput data information such as audio and video collected by drones.

[0069] 1. Channel model;

[0070] This embodiment adopts the urban low-altitude channel model based on probabilistic line of sight (LoS) wireless transmission, comprehensively considers the impact of building occlusion between drones on signal propagation, and derives the average path loss of direct communication between drones. Assume that the scenario is a system composed of T very short timestamps, where t∈{1,2,...,T}, then for each timestamp t, the drone is static. Let the coordinates of the drone at time t be The distance between drone a and drone b is Therefore, the channel gain between UAV a and UAV b can be expressed as:

[0071]

[0072] Among them, β represents the large-scale fading factor; h is the small-scale fading factor, and it satisfies the square expectation of 1, that is,

[0073] In real situations, drones may not have any additional information about their altitude, exact location, number of obstacles, and channel conditions. Therefore, when designing drone-based communication systems, the randomness generated by line-of-sight and non-line-of-sight links must be considered. For air-to-air communication, the line-of-sight LoS probability between drone a and drone b is modeled based on the environment, the position between the drones, and the elevation angle:

[0074]

[0075] where C and D represent propagation parameters and constant values ​​that depend on the carrier frequency and the type of environment, such as rural, urban, or built-up city. represents the elevation angle. According to formula (2), the larger the elevation angle, the greater the probability of LoS. In addition, the UAV equipment channel gain is introduced:

[0076]

[0077] Among them, f c is the carrier frequency, α is the path loss exponent, η1 and η2 (η2>η1>1) are the additional path loss coefficients in the LoS and NLoS cases, respectively, and c is the speed of light. In addition, the channel gain determined by LoS and NLoS can be corrected as follows:

[0078]

[0079] Among them, the regularized LoS probability is β0=([4πf c ] / c) -α represents the channel gain when the distance is 1. Therefore, the signal power received by drone a from drone b can be expressed as: Among them, p r is the received power, p t is the transmission power.

[0080] At the same time, the transmission rate between drones can be expressed as:

[0081]

[0082] 2. High frequency data link model;

[0083] When a drone swarm is performing a mission, the drone communication system can be regarded as a relay network, and the remote transmission interaction of data needs to be forwarded through other drones. The essence of the drone self-organizing network link design is to ensure that there is at least one reachable path between any two drones in the entire network, that is, to achieve full connectivity of the network. In addition, an important indicator for evaluating the efficient collaborative work of a drone swarm is the average path delay of the network, which reflects the frequency of network data exchange and is expressed as:

[0084]

[0085] in, is the transmission delay from drone a to drone b. Assume the length of the transmission data packet is L (a,b) , assuming the shortest path from a to b is H (a,b) , R is the transmission rate from i to j, then It can be expressed as:

[0086]

[0087] In addition, the frequency spectrum resources that can be used by drone ad hoc radio stations to build a high-frequency data network are limited, resulting in an upper limit on the number of high-frequency data links in the system. This embodiment defines the overhead of building a direct link from drone a to drone b as:

[0088]

[0089] Where c is the link cost per unit distance.

[0090] 3. UAV networking method based on dual links

[0091] 3.1. Low frequency control link networking method;

[0092] The traditional drone networking mode adopts the method of global traversal plus centralized control, which is suitable for scenarios where the nodes are close and few in number, and the communication channels are pre-allocated. However, due to the long distance between drones in urban low-altitude business drone groups and the lack of ground control centers, the power of a single drone is often unable to meet the full network coverage, resulting in the inability to achieve centralized unified networking.

[0093] Considering the above scenario, as an additional implementation method, this embodiment proposes a fully distributed control link networking method: all drones first broadcast their own information at maximum power to achieve signaling and information interaction within a certain range; then, based on the information received from other drones, link pairing between drones is achieved and the overall network is built. Figure 2 The specific networking method is as follows:

[0094] Equipment requirements: Each drone is equipped with a Wifi HaLow protocol communication module that supports networking functions.

[0095] Step 1: Plan the network topology: determine the location and number of nodes in the ad hoc network and how they are connected;

[0096] (1) Broadcast its own information (SSID, etc.) at maximum power;

[0097] (2) Receive broadcast information from surrounding drones and establish a link to build a preferred neighbor list based on the received signal strength;

[0098] (3) broadcast its own link construction preference list;

[0099] Based on the preference list received from surrounding drones, a link building matching request is issued;

[0100] (4) After receiving the link construction request, the matching is completed and the transmission power is adjusted (the power level only needs to meet the power required for the connection of the farthest node) to realize the construction of the respective network topology.

[0101] Step 2: Configure self-grouping nodes;

[0102] (1) Initialize nodes: Configure the network name (SSID), security settings (such as WPA3 encryption), and other basic network parameters for each self-organizing node.

[0103] (2) Enable HaLow mode: Ensure that each ad hoc node supports the HaLow standard and enables HaLow mode in its firmware settings.

[0104] Step 3: Establish a self-organizing network of drones;

[0105] (1) Backhaul configuration: Backhaul refers to the connection between ad hoc nodes. Under the HaLow protocol, these nodes will establish wireless connections through the 840MHz frequency band.

[0106] (2) Routing configuration: Ad hoc nodes need to configure routing information so that data packets can be effectively transmitted in the network. This is usually done automatically through dynamic routing protocols (such as 802.11s).

[0107] Step 4: Connect nodes;

[0108] (1) Scanning and discovery: The self-organizing node will periodically build a preferred neighbor list based on the links obtained in step 1 and look for other self-organizing nodes to establish connections.

[0109] (2) Connection and synchronization: Nodes establish connections through the HaLow protocol and perform time and frequency synchronization.

[0110] Step 5: Optimize and adjust;

[0111] (1) Channel selection: Each drone selects the best wireless channel based on its own connection conditions to reduce interference and improve network performance.

[0112] (2) Adjusting power and coverage: Each drone adjusts its transmission power according to the actual environment and the distance between nodes to optimize coverage and network performance.

[0113] 3.2, High frequency data link networking algorithm;

[0114] As an additional greedy-based implementation method, this embodiment proposes a high-frequency data link construction algorithm based on control information. After each timestamp, the drone performs a link establishment with the best utility. By using this algorithm, the drone can maintain a fully connected network and maintain efficient data transmission during business execution. The specific algorithm implementation idea is as follows: We first obtain information such as the number, location, and movement trajectory of drones in the global network based on the control information. Then, an initial high-frequency data link is established with lower power, and the network composed of drones communicating with maximum power and the initial link difference are evaluated to obtain the optional link set L.

[0115] As an incremental greedy implementation, a link is added in each round to ensure that this link can maximize the utility of reducing the overall network delay. The link utility function is Where k+1 represents the (k+1)th iteration of establishing a link. represents the utility function of adding the (k+1)th critical edge, T k is the k-th overall network average path delay, is the overall network average path delay when adding a remote link e(i,j) (i.e., establishing a remote link between nodes i and j) in the UAV communication network, c i, j is the cost of building a remote link from node i to node j. This link belongs to the optional link set L, and the link is deleted from L until there is no link that can improve the utility function or L is an empty set. Based on the above analysis, we summarize the algorithm in Algorithm 1, where T th For the delay requirement, R pis a set of high-frequency data links, and k is the number of iterations (the number of additional links constructed).

[0116]

[0117] Figure 3 is a schematic diagram of an initial high frequency data link network of an embodiment; Figure 4 Schematic diagram of an optimized high-frequency data link network of an embodiment.

[0118] The main innovations of this embodiment are: (1) a high-frequency dual-frequency link UAV networking architecture based on the separation of control link and high-frequency data link; (2) two networking algorithms for control link and high-frequency data link, the first group is a fully distributed networking algorithm for control link, and the second group is a high-frequency data link networking algorithm based on control information.

[0119] 4. Simulation Results

[0120] This embodiment simulates the process of networking multiple drones at low altitude in a city. The experimental simulation scene is a 1000m*1000m*200m urban scene, the number of drones is 16, the initial positions are randomly distributed in the scene, the mobile model refers to the Markov mobile model, and the initial positions of the drones are randomly distributed. Combined with the simulation environment of this embodiment, the network simulation parameters are shown in Table 1 below.

[0121] Table 1

[0122]

[0123] Embodiment 2

[0124] Based on the same inventive concept, this embodiment also provides a low-altitude UAV group dual-frequency link emergency networking system, including:

[0125] The first link building module is used to build a low-frequency control link of the low-altitude UAV, wherein the low-frequency control link adopts a fully distributed control link networking mode;

[0126] An information acquisition module, used to share network control data through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources;

[0127] A second link building module, used to build a high-frequency data link according to the global information, and perform data transmission through the high-frequency data link;

[0128] The dual-frequency link emergency networking construction module is used to build a dual-frequency link emergency networking based on the low-frequency control link and the high-frequency data link by combining high and low frequencies.

[0129] The dual-frequency link emergency networking system for a low-altitude UAV swarm provided in this embodiment has all the advantages of the dual-frequency link emergency networking method for a low-altitude UAV swarm provided in the first embodiment.

[0130] Embodiment 3

[0131] This embodiment further discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method described in the first embodiment.

[0132] Embodiment 4

[0133] This embodiment further discloses a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in the first embodiment are implemented.

[0134] Embodiment 5

[0135] This embodiment also discloses a computer program product, including a computer program, which implements the steps of the method described in the first embodiment when executed by a processor.

[0136] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A dual-frequency link emergency networking method for low-altitude drone groups, characterized in that: The following steps are involved: Constructing a low-frequency control link for a low-altitude UAV, wherein the low-frequency control link adopts a fully distributed control link networking mode; Sharing network control data through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources; constructing a high-frequency data link according to the global information, and transmitting data through the high-frequency data link; Based on the low-frequency control link and the high-frequency data link, a dual-frequency link emergency network is built by combining high and low frequencies.

2. The low-altitude UAV group dual-frequency link emergency networking method according to claim 1 is characterized in that: Building a low-frequency control link for a low-altitude drone includes: Each drone broadcasts its own information at maximum power, interacts with the information, and obtains information about surrounding drones; Based on the information of surrounding drones, the links between drones are paired and low-frequency control links for low-altitude drones are constructed.

3. The low-altitude UAV group dual-frequency link emergency networking method according to claim 1 is characterized in that: The low-frequency control link adopts a networking module that supports the Wifi Halow protocol, and the frequency band is selected as 840MHz.

4. The low-altitude UAV group dual-frequency link emergency networking method according to claim 1 is characterized in that: Building a high-frequency data link includes: establishing an initial high frequency data link according to the global information; The difference between the network composed of the drones communicating at maximum power and the initial high-frequency data link is evaluated to obtain an optional link set; In each round, a link providing maximum utility is searched from the optional link set, wherein the link belongs to the optional link set; The link is deleted from the optional link set until the optional link set is an empty set or there is no link that can increase the utility.

5. The low-altitude UAV group dual-frequency link emergency networking method according to claim 1 is characterized in that: It also includes a channel model based on probabilistic line-of-sight wireless transmission, comprehensively considers the impact of building obstruction between drones on signal propagation, and derives the average path loss for direct communication between drones.

6. The low-altitude UAV group dual-frequency link emergency networking method according to claim 1 is characterized in that: It also includes the process of optimizing the emergency networking of dual-frequency links: Select different transmission carrier frequencies according to the transmission requirements of different types of information of drones; According to the actual environment of each drone and the distance between nodes, the transmission power is adjusted to build a suitable transmission link.

7. A dual-frequency link emergency networking system for low-altitude drone groups, characterized in that: include: The first link building module is used to build a low-frequency control link of the low-altitude UAV, wherein the low-frequency control link adopts a fully distributed control link networking mode; An information acquisition module, used to share network control data through the low-frequency control link to obtain global information of the control link, wherein the global information includes UAV positioning information, physical environment and communication resources; A second link building module, used to build a high-frequency data link according to the global information, and perform data transmission through the high-frequency data link; The dual-frequency link emergency networking construction module is used to build a dual-frequency link emergency networking based on the low-frequency control link and the high-frequency data link by combining high and low frequencies.

8. A computer device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to claims 1 to 6 are implemented.

Images