Unmanned aerial vehicle beyond visual range multi-network fusion data chain

Abstract

The invention relates to the technical field of unmanned aerial vehicle over-the-horizon communication, in particular to an unmanned aerial vehicle over-the-horizon multi-network fusion data link, which comprises a plurality of communication modules, a core board and a system interface board which are vertically stacked, supports parallel access of a plurality of different operator SIM cards, and realizes bandwidth aggregation and millisecond link switching through an intelligent fusion algorithm. According to the invention, the transmission rate and the link reliability can be significantly improved, the backhaul data volume is reduced in combination with edge calculation preprocessing, the weight of the whole machine is less than 100 grams, the system is adapted to a mainstream unmanned aerial vehicle platform, and the requirements of 4K video real-time backhaul and high-stability communication in a complex environment are met.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) communication technology, and in particular to a UAV beyond-line-of-sight multi-network fusion data link. Background Technology

[0002] With the widespread application of drones in low-altitude economic scenarios such as public safety, power line inspection, traffic monitoring, logistics delivery, and agricultural monitoring, higher demands are being placed on beyond-line-of-sight (BLOS) communication capabilities, especially in terms of transmission rate, link stability, and mission continuity. Traditional drone communication systems generally rely on a single communication link, typically using a single 4G / 5G SIM card or a dedicated wireless image transmission module for data transmission. However, in complex geographical environments such as mountainous areas, densely populated urban areas with high-rise buildings, or areas with severe electromagnetic interference, a single link is highly susceptible to signal obstruction, multipath effects, or network congestion, leading to communication interruptions, video stuttering, or even mission failures, severely restricting the reliable deployment of drones in critical business scenarios. Furthermore, while some high-reliability scenarios can achieve BLOS connections using satellite communication, its equipment is expensive, consumes a lot of power, and is complex to deploy, making it difficult to popularize in small and medium-sized industry applications.

[0003] While existing technologies attempt to improve communication robustness through multi-card paralleling or simple link switching, they generally suffer from low integration, high switching latency, and a lack of intelligent load balancing mechanisms, failing to achieve true bandwidth aggregation and seamless disaster recovery. Especially under the dynamic flight conditions of UAVs with high-speed movement and frequent attitude changes, traditional solutions struggle to perceive the quality of each link in real time and respond within milliseconds, resulting in ineffective utilization of redundant link resources. Furthermore, existing equipment is bulky and heavy, making it difficult to adapt to mainstream consumer or industrial UAV platforms, limiting its application in lightweight, long-endurance missions. Therefore, there is an urgent need for a highly integrated, lightweight multi-network converged communication architecture that can deeply integrate 4G / 5G and IoT card resources from multiple operators. Through intelligent algorithms, it can achieve dynamic bandwidth aggregation, millisecond-level fault switching, and edge data preprocessing, thereby significantly improving the transmission performance, stability, and cost-effectiveness of UAV beyond-line-of-sight data links without relying on satellite communication, providing key technical support for the safe and efficient operation of the low-altitude economy. Summary of the Invention

[0004] This invention addresses the technical shortcomings of existing UAVs relying on a single communication link during beyond-visual-range (BVR) flight, such as limited bandwidth, unstable signals, easy link interruption, and high system costs. It provides a UAV BVR multi-network fusion data link device and its system architecture. This device solves the problems of poor communication continuity, insufficient effective bandwidth, and weak equipment adaptability in complex electromagnetic environments through parallel access of multiple communication links, intelligent fusion scheduling, and highly integrated hardware design.

[0005] This invention provides a beyond-line-of-sight (BLOS) multi-network fusion data link device for unmanned aerial vehicles (UAVs), including a housing. An air inlet is located on one side of the housing, and an air outlet is located on the opposite side, forming a directional airflow channel within the housing. A panel is fixedly mounted on the front of the housing. The housing employs a vertically stacked multi-layer modular structure, with a first communication module, a second communication module, a third communication module, a core board, and a system interface board arranged sequentially from bottom to top. Adjacent modules are electrically interconnected via board-to-board connectors or flexible printed circuits (FPCs). The overall weight is controlled to within 100 grams, and it can be directly mounted on the onboard interfaces of mainstream UAV platforms such as DJI, Autel, Ziyan, and KOBIT.

[0006] Each communication module is equipped with an independent SIM card socket and a communication main control chip. The communication main control chip is a communication module that supports 4G / 5G or narrowband Internet of Things (NB-IoT, Cat.1, etc.) protocols. Each communication module is also equipped with an MMCX antenna mount for connecting an external antenna. An antenna cover is fixedly installed on the inner wall of the rear panel of the housing.

[0007] Furthermore, the core board is equipped with an embedded processor and storage unit, and has a self-developed multi-link intelligent fusion algorithm program embedded in it; the algorithm performs the following steps when running: S1: Periodically collect real-time link status parameters of each communication module, including but not limited to reference signal received power (RSRP), signal-to-noise ratio (SNR), end-to-end delay, packet loss rate and available bandwidth; S2: Construct a link quality assessment model based on the above parameters and assign dynamic weights to each link; S3: Execute the bandwidth aggregation strategy according to the weight results, distribute the data to be transmitted to each link proportionally, and implement forward error correction coding simultaneously; S4: When the packet loss rate of any link exceeds the preset threshold or the RSRP is lower than -110 dBm, the link switching mechanism is triggered, and the data stream carried by the link is migrated to other links within 100 milliseconds to complete the seamless hot backup switching. S5: Continuously monitor the recovery status of interrupted links. If the link quality recovers to above the usable threshold, it will be reintegrated into the aggregation pool to participate in data transmission.

[0008] Specifically, the core board integrates an edge computing unit that deploys lightweight image processing or AI inference models. Before data backhaul, it performs preprocessing operations on the raw video stream or sensor data from the task payload, including H.265 encoding compression, region of interest (ROI) cropping, initial target detection screening, or metadata extraction. The preprocessed data volume is reduced by 30%–70%, thereby reducing the effective bandwidth requirements of the backhaul link and reducing operator traffic billing expenses.

[0009] Furthermore, the system interface board is equipped with an 8-pin network port and a first FPC socket; the 8-pin network port is connected to the UAV network interface through an Ethernet physical layer chip to output aggregated network data streams; the first FPC socket is connected to the serial communication interface of the UAV flight control system through a flexible ribbon cable to realize link status information reporting and control command interaction; the system interface board is also equipped with a power management interface to provide stable power to each lower-level module.

[0010] The power supply is uniformly provided by a power board fixed to the inner surface of the outer casing side wall. The power board integrates a DC-DC voltage conversion circuit, an overcurrent protection module, and an XT30 socket. The XT30 socket is connected to the output terminal of the UAV's onboard battery via a power cable, with an input voltage range of 12V–52V. The power board is also equipped with a miniature axial fan and a power indicator light. The fan's air inlet faces the air inlet, and its air outlet faces the air outlet. It automatically starts when the core board temperature exceeds 65°C, forcing airflow vertically through the communication modules and the core board surface to achieve active air cooling. The power indicator light displays the power supply status and illuminates a green LED when the input voltage is within the normal operating range.

[0011] Furthermore, the first, second, and third communication modules adopt the same circuit topology in their hardware design, each including a communication module, SIM card socket, MMCX antenna mount, power filter circuit, and local microcontroller; each module is powered by an independent power domain and is equipped with ferrite beads and shielding covers for electromagnetic compatibility isolation; the three communication modules can respectively insert SIM cards from China Mobile, China Unicom, China Telecom, or other virtual operators, supporting simultaneous access to three heterogeneous public networks; each communication module is connected to the core board via a USB 2.0 interface, with a data throughput rate of no less than 300Mbps.

[0012] The beneficial effects of this invention are as follows: Through the collaborative design of the above-mentioned hardware architecture and software algorithm, deep integration of public network links from multiple operators is achieved: At the data transmission level, after bandwidth aggregation, the measured downlink speed of three independent 4G / 5G links can reach 3-5 times that of a single link, and can stably maintain above 120 Mbps in typical urban environments, meeting the real-time backhaul requirements of 4K@30fps H.265 video streams; In terms of link reliability, when any operator's network experiences service interruption due to obstruction, congestion, or base station switching failure, the remaining links take over all service flows within 100 milliseconds, with communication interruption time lower than the threshold perceptible to the human eye, and the task continuity guarantee rate is increased to over 99.5%; In terms of cost control, there is no need to deploy dedicated microwave or satellite communication terminals, and stable communication beyond line of sight for more than 20 kilometers can be achieved solely by relying on existing public network infrastructure, reducing the annual communication cost per unit by more than 60%; This device supports remote firmware upgrades and link policy configuration. The ground station can send new fusion algorithm parameters or edge computing models through the 8-pin network port to achieve over-the-air software-defined communication capabilities. The whole machine has passed IP54 protection level certification and can work continuously for more than 8 hours in an ambient temperature range of -20℃ to +60℃. It has completed more than 2,000 field verifications in scenarios such as public security countermeasures patrol, power grid transmission line inspection, highway accident investigation and mountain emergency communication. The system's mean time between failures (MTBF) exceeds 500 hours, making it ready for engineering deployment. This invention constructs a lightweight, highly reliable, and low-cost UAV beyond-line-of-sight multi-network fusion data link system through a vertically stacked high-density integrated structure, a multi-heterogeneous public network link parallel access mechanism, a millisecond-level intelligent switching algorithm, and airborne edge preprocessing capabilities. It solves the core problems of bandwidth bottleneck, link vulnerability, and poor platform adaptability in existing technologies, and provides a scalable communication infrastructure for various beyond-line-of-sight operation scenarios in the low-altitude economy. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the UAV beyond-line-of-sight multi-network fusion data link device of the present invention; The attached figures are labeled as follows: 1. Outer shell; 2. Air inlet; 3. Air outlet; 4. Front panel; 5. First communication module; 6. Second communication module; 7. Third communication module; 8. Core board; 9. System interface board; 10. B2B socket; 11. First FPC socket; 12. 8-pin network port; 13. 4G indicator light; 14. Second FPC socket; 15. SIM card socket; 16. 4G module; 17. Antenna cover; 18. Power board; 19. Fan; 20. XT30 socket; 21. Power indicator light. Detailed Implementation

[0014] 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 embodiments of the present invention, and not all embodiments. 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.

[0015] Specific implementation examples are given below.

[0016] The UAV beyond-line-of-sight multi-network fusion data link device of the present invention, such as Figure 1As shown, the overall structure includes a shell 1, which is made of engineering plastic and has overall dimensions of 90mm×60mm×25mm. The weight is controlled within 100 grams to meet the mounting requirements of mainstream consumer and industrial drones. An air inlet 2 is opened on one side of the shell 1, and an air outlet 3 is opened on the opposite side. The air inlet 2 and the air outlet 3 form a vertical directional air channel inside the shell to guide airflow for active heat dissipation of the internal high-heat modules. A panel 4 is fixedly installed on the front of the shell 1. The panel 4 is made of the same engineering plastic as the shell and has multiple status indicator light windows to facilitate users to observe the operating status of the device. Inside the outer casing 1, a vertically stacked multi-layer modular structure is adopted, with the first communication module 5, the second communication module 6, the third communication module 7, the core board 8, and the system interface board 9 arranged sequentially from bottom to top. Adjacent modules are electrically interconnected via B2B sockets 10 or flexible printed circuits (FPCs). The core board 8 and the system interface board 9 are connected via B2B connectors, and the first communication module 5, the second communication module 6, the third communication module 7, and the system interface board 9 are connected via FPC flexible cables, ensuring high-speed signal integrity while maintaining structural compactness. This stacked structure not only saves space but also effectively shortens the length of high-frequency signal traces and reduces electromagnetic interference. A 4G indicator light 13 is installed on the third communication module 7. Each communication module is equipped with an independent SIM card socket 15 and a communication main control chip. The communication main control chip is a communication module 16 that supports 4G / 5G or narrowband IoT (NB-IoT, Cat.1, etc.) protocols, such as Qualcomm Snapdragon X24 or Quectel RM500Q series modules. The first communication module 5, the second communication module 6, and the third communication module 7 adopt the same circuit topology in hardware design, and each includes a communication module 16, a SIM card socket 15, an MMCX antenna holder 8, a power filtering circuit, and a local microcontroller. The three communication modules can respectively insert SIM cards from China Mobile, China Unicom, China Telecom, or other virtual operators, and support simultaneous access to three heterogeneous public networks. Each communication module 16 is connected to the core board 8 through a USB 2.0 interface, with a data throughput rate of not less than 300 Mbps, ensuring high bandwidth transmission capability after multi-link aggregation. Each communication module is also equipped with an MMCX antenna mount 8 for connecting an external antenna; an antenna cover plate 17 is fixedly installed on the inner wall of the rear panel of the housing 1. The antenna cover plate 17 has reserved MMCX antenna mount holes. The radio frequency antenna is connected to the communication module through the MMCX interface, including low frequency band (600–960 MHz), mid frequency band (1710–2690 MHz) and high frequency band (3300–3800 MHz) omnidirectional antennas, covering the mainstream 4G / 5G and IoT communication frequency bands; The core board 8 is equipped with an embedded processor (such as Rockchip RK3566 or NXP i.MX8M Mini) and LPDDR4 memory, and has a self-developed multi-link intelligent fusion algorithm program embedded in it. The algorithm performs the following steps when running: S1: Periodically collect the real-time link status parameters of each communication module, including reference signal received power (RSRP), signal-to-noise ratio (SNR), end-to-end delay, packet loss rate and available bandwidth, with a sampling period of 100 milliseconds; S2: Construct a link quality assessment model based on the above parameters, and use a weighted scoring method to assign dynamic weights to each link. The weight calculation formula is W = α·RSRP + β·(1 / delay) + γ·(1 - packet loss rate), where α, β and γ are configurable coefficients; S3: Execute a bandwidth aggregation strategy according to the weight results, distribute the data to be transmitted to each link proportionally, and simultaneously implement forward error correction coding (FEC). The coding redundancy is dynamically adjusted according to the current link packet loss rate; S4: When the packet loss rate of any link exceeds a preset threshold (such as 5%) or RSRP is lower than -110 When the data loss rate reaches dBm, the link switching mechanism is triggered, and the data stream carried by the link is migrated to other links within 100 milliseconds to complete the seamless hot backup switch; S5: Continuously monitor the recovery status of the interrupted link. If the link quality recovers to above the usable threshold (e.g., RSRP > -100 dBm and packet loss rate < 2%), it will be reintegrated into the aggregation pool to participate in data transmission. Specifically, the core board 8 integrates an edge computing unit, which deploys lightweight image processing or AI inference models (such as YOLOv5s or MobileNetV2). Before data backhaul, it performs preprocessing operations on the raw video stream or sensor data from the task payload, including H.265 encoding compression, region of interest (ROI) cropping, initial target detection screening, or metadata extraction. For example, in power line inspection scenarios, drones equipped with visible light and infrared dual-light pods can have their edge computing units identify defects such as insulator damage and broken conductor strands in real time, and only transmit the labeled keyframes and alarm information back, reducing the data volume by 30%–70%, thereby reducing the effective bandwidth requirements of the backhaul link and reducing the operator's traffic billing expenses. The system interface board 9 is equipped with an 8-pin network port 12 and a first FPC socket 11. The 8-pin network port 12 connects to the UAV through an Ethernet physical layer chip (such as RTL8211F) to output aggregated network data streams. It supports adaptive rates of 10 / 100 / 1000Mbps and enables link status information reporting (such as current aggregated bandwidth, RSRP values ​​of each link, and fault alarms) and control command interaction (such as remote module restart and switching of working modes). The system interface board 9 is also equipped with a power management interface, which provides stable power supplies of 3.3V and 5V to each lower-level module through multiple DC-DC regulators. Power is supplied uniformly by a power board 18 fixed to the inner surface of the side wall of the outer casing 1. The power board 18 integrates a wide-input DC-DC voltage conversion circuit (input range 12V–52V), an overcurrent protection module, and an XT30 socket 20. The XT30 socket 20 is connected to the output end of the drone's onboard battery via a power cable, and is compatible with multiple platforms such as DJI TB60 and Autel Smart Battery. The power board 18 is also equipped with a miniature axial fan 19 and a power indicator light 21. The air inlet of the fan 19 faces the air inlet 2, and the air outlet faces the air outlet 3. When the temperature of the core board 8 exceeds 65℃, the temperature control circuit automatically starts, forcing the airflow to flow vertically through the communication modules and the surface of the core board 8 to achieve active air cooling and ensure thermal stability under long-term high-load operation. The power indicator light 21 is a dual-color LED, with green indicating normal input voltage (12V–52V) and red indicating undervoltage or overcurrent fault. In practical applications, such as power line inspection missions in mountainous areas, after the drone carrying this device takes off, the first communication module 5 is inserted with a China Mobile SIM card, the second communication module 6 with a China Unicom SIM card, and the third communication module 7 with a China Telecom SIM card. Initially, all three cards are in areas with good signal coverage. The intelligent fusion algorithm allocates data streams in a 4:3:3 ratio based on the RSRP values ​​of each link (e.g., -85 dBm, -90 dBm, -88 dBm), achieving an aggregated downlink rate of 150 Mbps, enabling smooth transmission of 4K@30fps H.265 video. When the drone enters a canyon area, the China Mobile signal rapidly attenuates to -115 dBm due to obstruction, accompanied by a high packet loss rate. The algorithm detects the anomaly within 80 milliseconds and immediately migrates all data streams from that link to the other two links. During the switching process, the video stream flows smoothly without interruption. Simultaneously, the edge computing unit performs ROI cropping on the video, retaining only the transmission tower area, reducing the transmission bitrate from 50 Mbps to 20 Mbps. Mbps, further ensuring transmission continuity under weak network conditions; after the mission is completed, the ground station sends out a new AI model through the 8-pin network port 12 for bird nest identification in the next mission, realizing the upgrade of airborne software-defined communication capabilities; The entire unit has passed IP54 protection level certification and can operate continuously for more than 8 hours in an ambient temperature range of -20℃ to +60℃. It has completed more than 2,000 field verifications in scenarios such as public security countermeasures patrol, power grid transmission line inspection, highway accident investigation and mountain emergency communication. The system's mean time between failures (MTBF) exceeds 500 hours. Real-world testing shows that in complex urban electromagnetic environments, the downlink speed after aggregation of three 4G links is stable at over 120 Mbps, the link interruption recovery time is less than 100 milliseconds, the mission continuity guarantee rate is improved to over 99.5%, and the annual communication cost per unit is reduced by more than 60% compared to satellite solutions, making it suitable for engineering deployment.

[0017] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A UAV beyond-line-of-sight multi-network fusion data link device, comprising a housing (1), wherein an air inlet (2) is provided on one side of the housing (1), and an air outlet (3) is provided on the opposite side, the air inlet (2) and the air outlet (3) forming a directional air duct inside the housing; a panel (4) is fixedly installed on the front of the housing (1); characterized in that: The outer shell (1) adopts a vertically stacked multi-layer modular structure, with a first communication module (5), a second communication module (6), a third communication module (7), a core board (8), and a system interface board (9) arranged sequentially from bottom to top; adjacent modules are electrically interconnected through board-to-board connectors or flexible printed circuits; the first communication module (5), the second communication module (6), and the third communication module (7) are all equipped with independent SIM card sockets (15) and communication modules (16) supporting 4G / 5G or narrowband IoT protocols; the core board (8) is also equipped with a system interface board (9). The board (8) is solidified with a multi-link intelligent fusion algorithm program; the system interface board (9) is provided with an 8-pin network port (12) and a first FPC socket (11); an antenna cover plate (17) is fixedly installed on the inner wall of the rear panel of the outer shell (1), and an MMCX antenna mount hole is reserved on the antenna cover plate (17). The radio frequency antenna is connected to the communication module through the MMCX interface; the power supply is uniformly supplied by the power board (18) fixed on the inner surface of the side wall of the outer shell (1), and the power board (18) is provided with an XT30 socket (20) for connecting the UAV airborne power supply interface.

2. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 1, characterized in that: The core board (8) integrates an edge computing unit, which is equipped with a lightweight image processing model or an AI inference model to perform at least one preprocessing operation on the raw video stream or sensor data from the task payload, including H.265 encoding compression, region of interest cropping, target detection screening, or metadata extraction.

3. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 2, characterized in that: After performing preprocessing operations, the edge computing unit outputs the processed data through an 8-pin network port (12), and the first FPC socket (11) is connected to the FPC sockets of other communication modules through a flexible ribbon cable for data communication and link control.

4. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 1, characterized in that: The first communication module (5), the second communication module (6) and the third communication module (7) adopt the same circuit topology in hardware, and each includes a communication module (16), a SIM card socket (15), an MMCX antenna holder, a power filtering circuit and a local microcontroller; each communication module is powered by an independent power domain and is equipped with a ferrite bead and a shield for electromagnetic compatibility isolation.

5. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 4, characterized in that: Each communication module (16) is connected to the core board (8) via a USB 2.0 interface, with a data throughput rate of not less than 300 Mbps.

6. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 1, characterized in that: The power board (18) integrates a DC-DC voltage conversion circuit, an overcurrent protection module, and a miniature axial fan (19); the air inlet of the miniature axial fan (19) faces the air inlet (2), the air outlet faces the air outlet (3), and it automatically starts when the temperature of the core board (8) exceeds 65°C; the power board (18) is also equipped with a power indicator light (21) to indicate the power supply status.

7. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 1, characterized in that: The multi-link intelligent fusion algorithm program performs the following steps during runtime: periodically collecting the reference signal received power, signal-to-noise ratio, end-to-end delay, packet loss rate, and available bandwidth of each communication module; A link quality assessment model is constructed based on the collected parameters and dynamic weights are assigned. The data to be transmitted is distributed proportionally to each link according to the weight and forward error correction coding is implemented; when the packet loss rate of any link exceeds 5% or the reference signal received power is lower than -110 dBm, the data stream carried by that link is migrated to the other links within 100 milliseconds; the recovery status of the interrupted links is continuously monitored, and they are re-included into the aggregation pool when their reference signal received power is higher than -100 dBm and the packet loss rate is lower than 2%.

8. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 1, characterized in that: The 8-pin network port (12) on the system interface board (9) is connected to the UAV network interface (8) through the Ethernet physical layer chip, supporting an adaptive rate of 10 / 100 / 1000Mbps.

9. The UAV beyond-line-of-sight multi-network fusion data link device as described in claim 1, characterized in that: The outer shell (1) is made of engineering plastic, with an overall size of 90mm×60mm×25mm and a weight of no more than 100 grams; the panel (4) is made of transparent acrylic, and has a status indicator window for observing the operating status of the equipment.

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