A method and system for composite use of optical fiber and wireless link for unmanned aerial vehicle communication

Abstract

The application discloses a kind of optical fiber and wireless link composite use unmanned plane communication method and system, belong to unmanned plane communication technical field.System is configured with signal selection module of time synchronization clock in the unmanned plane end built-in.The optical fiber link is used preferentially in flight, and optical fiber and wireless double link keep time synchronization hot standby output state;System periodically detects optical fiber heartbeat signal, if it is disconnected, immediately trigger rocker back to the middle instruction, maintain instantaneous attitude smooth transition to hover, and start 15 seconds false line fault tolerance timing;If it is not recovered after timeout, it is switched to synchronous wireless link takeover control immediately;If wireless is also lost, it is executed along the heading return and continuously searches signal.The application is combined with the flight control logic deeply by underlying time synchronization, effectively filters the false line of optical fiber caused by maneuvering flight, eliminates the communication vacuum period of traditional network reconnection, realizes zero time delay seamless takeover under complex environment.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) communication technology, specifically relating to a UAV communication method and system that uses a combination of optical fiber and wireless links. Background Technology

[0002] In scenarios such as military reconnaissance and precision strikes, disaster relief, and covert inspections in densely populated urban areas, fiber optic drones play an irreplaceable role. Existing fiber optic drones primarily rely on optical fibers for communication between the ground station and the drone itself. The communication signal propagates via total internal reflection within the fiber, offering significant advantages such as strong anti-interference capabilities, stable communication, and low latency. Typically, fiber optic drones are equipped with optical transceivers at both the ground and aircraft ends, with a fiber optic cable delivery reel mounted on the aircraft end.

[0003] However, existing purely fiber-optic controlled drones suffer from a fatal flaw in practical use: a single communication link. Due to limitations in drone takeoff and payload capacity, the fiber optic cable used inside the fiber optic tube is typically extremely thin (usually between 0.25-0.5mm) to reduce weight. Based on the inherent physical property of fiber optic material—that it is "tensile-resistant but not bending-resistant"—fiber breakage (broken wires) frequently occurs when drones navigate complex terrain, perform violent maneuvers, or are affected by external environmental factors. Because the existing architecture lacks a redundant link mechanism, once a break occurs, the ground station control unit instantly and completely loses control and image transmission signals to the drone, potentially leading to a crash in severe cases. This reliance on fiber optic communication severely restricts the safety and reliability of drone operations.

[0004] Furthermore, in complex and harsh combat environments, when drones maneuver violently or fiber optic cables are pulled by external obstacles such as tree branches, the fiber optic cables are prone to sharp bends, causing a brief physical interruption of the optical signal (i.e., a "false break"). This interruption usually resolves itself after a few seconds as the cable stress dissipates. Traditional dual-link systems are highly susceptible to frequent link switching in the face of such brief false breaks; and conventional link switching requires re-establishing a handshake, resulting in a communication vacuum of several seconds. During high-speed maneuvers, this few seconds of loss of control or sudden braking and hovering can easily lead to the drone stalling and crashing. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to address the shortcomings of existing technologies by providing a UAV communication method and system that uses a combination of fiber optic and wireless links. By introducing an intelligent link routing mechanism and deeply integrating it with flight control logic, seamless takeover and recovery of the communication link can be ensured.

[0006] Technical Solution: This invention provides a UAV communication method that combines fiber optic and wireless links, applicable to a communication system including a ground terminal and a UAV terminal. The UAV terminal has a built-in signal selection module. The method includes the following steps:

[0007] S10. Before the UAV takes off, connect the optical fiber communication link and the wireless communication link between the ground terminal and the UAV terminal, and during the flight, the signal of the wireless communication link and the signal of the optical fiber communication link are kept in a synchronized output state based on the time synchronization clock built into the signal selection module.

[0008] S20. During the flight of the UAV, the signal selection module prioritizes receiving the signal transmitted by the optical fiber communication link and forwards the signal to the UAV flight controller to execute the flight mission;

[0009] S30. Monitor the heartbeat signal of the optical fiber communication link in real time. If the heartbeat signal is not detected within a specified time, determine that the optical fiber communication link is abnormal, control the UAV to automatically ignore any signal from the ground end, and trigger the execution of the preset joystick return command to control the UAV to enter the hovering waiting state, and start the preset time threshold timing at the same time.

[0010] S40. If the fiber optic communication link fails to reconnect within a preset time threshold, the signal selection module will instantly switch the communication channel to the wireless communication link that is already in a synchronized output state, and the wireless communication link will take over the control of the UAV.

[0011] Preferably, after step S40, a wireless link anomaly protection step is further included: if the flight distance of the UAV exceeds the effective communication distance of the wireless communication link, resulting in the loss of wireless signal, the UAV is controlled to return to the takeoff point along the flight path; during the UAV's return flight, the signal selection module continuously searches for the signal of the wireless communication link; if the UAV searches for and reconnects to the wireless communication link signal during flight, the UAV resumes performing the follow-up task; if the wireless communication link signal is not found continuously, the UAV performs a landing on the spot after returning to above the takeoff point.

[0012] In actual use, the drone may experience a false signal interruption during flight. When the fiber optic cable is bent significantly, the signal will be briefly interrupted. At this time, the fiber optic cable is not broken. The signal interruption due to the false signal interruption will usually be restored after a few seconds. Therefore, in actual use, a 15-second judgment is made. If the signal is suddenly interrupted under complex maneuvering conditions, the drone will still maintain the stability of the instantaneous attitude and rely on the high reliability algorithm of the flight control to achieve the attitude transition from maneuvering to stable hovering, thus achieving a smooth transition from maneuvering flight to hovering.

[0013] Preferably, in step S30: the preset time threshold is 15 seconds configured by the ground end; at the moment the hovering wait is triggered, the UAV maintains an instantaneous attitude and relies on the UAV flight control algorithm to achieve a smooth attitude transition from the current maneuver to a stable hovering state; if the signal of the fiber optic communication link is restored within the preset time threshold of 15 seconds, the anomaly is determined to be a false disconnection caused by a large-angle bend in the fiber optic cable, the signal selection module reconnects the fiber optic communication link, restores the signal from the ground end, and controls the UAV to complete the follow-up task.

[0014] The drone monitors heartbeat signals in real time at a frequency of 1 second. If no heartbeat signal is detected within 1 second, the drone will automatically ignore any signals from the ground and execute a hovering signal analogous to the remote control return signal on the ground. That is, it enters a hovering waiting state and begins a 15-second disconnection waiting judgment. If no signal is detected after 15 seconds, it is judged as a disconnection. If the signal is restored, the fiber optic cable is reconnected to respond to the signal from the ground.

[0015] Preferably, the signal selection module is internally configured with a main control chip, an S-bus channel selection module, and a network port channel selection module; in step S40, the signal selection module switches the communication channel to the wireless communication link in the following way: the main control chip controls the S-bus channel selection module and the network port channel selection module to perform channel switching, so that the signal of the S-bus port and the signal of the network port are switched from the optical fiber communication link to the wireless communication link instantaneously.

[0016] The signal selection module contains a time synchronization clock that controls the synchronous output of fiber optic communication and wireless communication signals. When using fiber optic communication, wireless communication is also outputting signals synchronously, but this wireless signal is not selected. The signal selection module is similar to a switch; when the switch is turned on, the wireless communication signal is naturally connected.

[0017] Preferably, the ground terminal and the UAV terminal transmit remote control signals through the Sbus port, and transmit image and data signals through the network port.

[0018] Preferably, the method also supports a single-link compatible operation mode: when the UAV is not connected to any signal of the wireless communication link, the signal selection module locks the use of the optical fiber communication link for control and data backhaul; when the UAV is not connected to any signal of the optical fiber communication link, the signal selection module locks the use of the wireless communication link for control and data backhaul.

[0019] On the other hand, the present invention also provides a drone communication system that uses a combination of optical fiber and wireless links to implement the above method, the system comprising: a ground terminal and a drone terminal;

[0020] The ground terminal includes: a handheld ground control station with a built-in wireless communication link module, and a ground-end optical transceiver connected to the handheld ground control station;

[0021] The UAV terminal includes: an airborne optical transceiver, an aircraft-side data link, a signal selection module, and a UAV flight controller;

[0022] The output of the airborne optical transceiver and the output of the aircraft data link are both connected to the input of the signal selection module, and the output of the signal selection module is connected to the input of the UAV flight controller.

[0023] Preferably, the signal selection module is externally configured with a first input interface group, a second input interface group, and a unique output interface group, and internally configured with a time synchronization clock. The first input interface group is connected to the airborne optical transceiver and is used to receive optical fiber communication link signals. The second input interface group is connected to the aircraft-side data link and is used to receive wireless communication link signals. The output interface group is connected to the input terminal of the UAV flight controller and is used to output a single-source composite signal to the UAV flight controller. Each of the first input interface group, the second input interface group, and the output interface group includes an Sbus signal channel interface and a network port signal channel interface. The time synchronization clock is used to control the optical fiber signal received by the first input interface group and the wireless signal received by the second input interface group to maintain time synchronization within the signal selection module, so as to provide instantaneous output during channel switching.

[0024] Preferably, the first input interface group consists of S-Bus port 1 and Ethernet port 1, the second input interface group consists of S-Bus port 2 and Ethernet port 2, and the output interface group consists of S-Bus output port and Ethernet output port; wherein, the corresponding interface of the airborne optical transceiver is connected to S-Bus port 1 and Ethernet port 1 of the signal selection module, the corresponding interface of the aircraft data link is connected to S-Bus port 2 and Ethernet port 2 of the signal selection module; the S-Bus output port of the signal selection module is connected to the corresponding S-Bus input port of the UAV flight controller, and the Ethernet output port of the signal selection module is connected to the corresponding Ethernet input port of the UAV flight controller.

[0025] Preferred, the internal circuit of the signal selection module consists of a main control chip, an Sbus switching chip, and a network port switching chip. The main control chip is an STM32G030K8T6 microcontroller, whose pins output SBUS_CTL and NET_CTL control signals. The Sbus switching chip uses an SN74LVC1G3157 multiplexer chip, whose control pin receives the SBUS_CTL control signal. The two input pins of the Sbus switching chip are connected to Sbus port 1 and Sbus port 2, respectively, and its output pin is connected to the Sbus output port. The network port switching chip uses a PI3L500-A network switch chip, whose gating control pin receives the NET_CTL control signal. The two sets of network signal input pins included in the network port switching chip are connected to network port 1 and network port 2, respectively, and one set of network signal output pins included in the chip is connected to the network port output port.

[0026] Beneficial effects: Compared with the prior art, the advantages of the present invention are as follows:

[0027] A signal selection module with multi-link access capability was added to the drone. Through the time synchronization clock configured inside the module, the fiber optic and wireless communication links maintain timeline synchronization and parallel hot standby output throughout the flight. In the event of fiber optic cable failure, since there is no need to re-establish the wireless network handshake and connection, only the physical layer channel needs to be switched instantaneously through the underlying control chip. This completely eliminates the communication vacuum period of several seconds caused by traditional network layer routing switching, truly achieving seamless takeover of control and breaking the predicament of traditional fiber optic drones losing control and crashing due to a single point of failure.

[0028] It employs a progressive mechanism of "1-second ultra-fast anti-interference lock-up + 15-second (configurable) false disconnection fault tolerance". When encountering complex terrain that causes the optical fiber to bend at a large angle, momentarily blocking the optical signal, the 1-second high-frequency heartbeat detection can quickly cut off the injection of chaotic signals and trigger the preset joystick return command; at the same time, combined with the flight control high-reliability algorithm, it maintains the instantaneous attitude at the moment of disconnection and smoothly transitions to stable hovering, completely solving the pain point of stall and crash caused by sudden braking during high-speed maneuvers. The subsequent 15-second fault tolerance buffer effectively filters out the "false disconnection" state before the stress of the optical fiber is released, avoiding flight control command disorder caused by frequent ping-pong switching of the communication link.

[0029] To address the extreme dead zone where wireless communication is also lost, this invention triggers a deep self-rescue logic of "returning along the flight path + continuous search en route." It cleverly utilizes the spatial mobility of the UAV to actively shorten the physical distance of wireless communication, maximizing the rescue of UAVs that have completely lost control due to long-distance disconnection. Simultaneously, the signal selection module adopts a hardware topology architecture with multi-channel input and a single output to the flight controller. This eliminates the need for complex link identification calculations in the flight control system and is inherently backward compatible with various mounting modes such as single fiber (for weight-reduced close-range reconnaissance) or single wireless, significantly improving the platform's flexible deployment capabilities for different mission scenarios.

[0030] To address the characteristics of complex UAV service flows, the signal selection module includes a dedicated "Sbus channel selection module" and a "Network port channel selection module" controlled by unified output signals (SBUS_CTL and NET_CTL) from the main control chip. This hardware-level synchronous switching mechanism, based on the same MCU clock cycle, ensures that in the event of a connection failure, the Sbus port responsible for low-level attitude control and the Network port responsible for high-level image payload data transmission can switch synchronously, avoiding the risk of misalignment or interruption between control signals and video feedback signals. Attached Figure Description

[0031] Figure 1 A schematic diagram illustrating the communication principle of combining optical fiber and wireless links provided in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of a standalone fiber optic wired communication transmission provided in an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of a standalone wireless communication transmission provided in an embodiment of the present invention;

[0034] Figure 4 This is a schematic diagram of the internal structure of the signal selection module provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of a signal selection module circuit provided in an embodiment of the present invention;

[0036] Figure 6 A flowchart illustrating the control logic for combined optical fiber and wireless link communication provided in an embodiment of the present invention. Detailed Implementation

[0037] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the embodiments described.

[0038] Example 1: As Figure 1 and Figure 4As shown, this embodiment provides a drone communication system that uses both fiber optic and wireless links. The system is physically divided into a ground-based end and a drone-based end.

[0039] At the ground end, handheld ground control stations and ground-end optical transceivers are deployed. The ground-end optical transceivers are essential photoelectric signal conversion devices for fiber optic communication, and they are equipped with fiber optic connection ports (FC ports), S-Bus ports, and Ethernet ports. The handheld ground control stations have built-in wireless communication link modules, which transmit wireless electromagnetic waves through the remote control antenna to transmit wireless map, data, and telemetry signals. They are also equipped with external S-Bus ports and external Ethernet ports.

[0040] On the UAV side, the main communication modules include: an airborne optical transceiver, an aircraft-side data link, a signal selection module, and the UAV flight controller. The airborne optical transceiver is responsible for fiber optic wired communication transmission, receiving optical signals and converting them into electrical signals. In actual use, the UAV carries an optical fiber tube (typically with a fiber diameter between 0.25-0.5mm to meet weight restrictions). The aircraft-side data link receives radio frequency signals transmitted by the ground station antenna, modulates and demodulates them, and then converts them into electrical signals.

[0041] like Figure 4 The signal selection module shown internally consists mainly of a main controller chip, an S-Bus channel selection module, and a network port channel selection module. Externally, the signal selection module is configured with a first input interface group, a second input interface group, and a unique output interface group. The first input interface group consists of S-Bus port 1 and network port 1; the second input interface group consists of S-Bus port 2 and network port 2; and the output interface group consists of an S-Bus output port and a network port output port. Specifically, the corresponding interfaces of the airborne optical transceiver are connected to S-Bus port 1 and network port 1; the network port of the aircraft data link is connected to network port 2 of the signal selection module, and the S-Bus port of the aircraft data link is connected to S-Bus port 2 of the signal selection module; the S-Bus output port of the signal selection module is connected to the corresponding S-Bus input port of the UAV flight controller, and the network port output port of the signal selection module is connected to the corresponding network port input port of the UAV flight controller.

[0042] In addition, the signal selection module is equipped with a time synchronization clock (which can be implemented by an internal timer of the main control chip or an external high-precision crystal oscillator). This time synchronization clock is used to control the signals received by the first input interface group (fiber optic end) and the signals received by the second input interface group (wireless end) to maintain strict synchronization of the time axis within the module. Even when using fiber optic communication, the wireless communication link is in a synchronous parallel receiving state, ready to provide instantaneous and seamless output when switching channels.

[0043] like Figure 5The schematic diagram of the signal selection module shown shows that the main control chip MCU is an STM32G030K8T6 microcontroller, the SBUS switching chip is an SN74LVC1G3157, and the network port switching chip is a PI3L500-A. The MCU performs logical judgment in its internal program. When switching is required, the MCU's control signals are used to control the switching operation instantaneously through its SBUS_CTL and NET_CTL, thus realizing the signal selection function.

[0044] In this architecture, regardless of whether the external signal is transmitted via fiber optics or wirelessly, the UAV flight controller only needs to read instructions and data from a single signal selection module, greatly simplifying the underlying processing logic of the flight control. Specifically, in practical hardware protocol applications, the Sbus protocol is primarily responsible for transmitting low-level remote control commands, while Ethernet (network port) is mainly responsible for transmitting large-capacity data such as video images.

[0045] Example 2: Based on the hardware of Example 1, combined with... Figure 6 The control logic diagram is provided, detailing the workflow of this method. When a drone employing composite communication performs missions in environments with strong electromagnetic interference or where signals are easily blocked:

[0046] Takeoff Preparation and Dual-Link Connection: Before takeoff, both the fiber optic cable and the wireless data link are connected. Due to the absolute advantages of fiber optics in terms of anti-interference and latency, after takeoff, the signal selection module prioritizes fiber optic communication. Its internal signal selection module prioritizes forwarding signals from Sbus port 1 and network port 1, that is, the Sbus output port forwards the Sbus port 1 signal, and the network port output port forwards the network port 1 signal.

[0047] Disconnection Detection and Fault-Tolerant Hovering: During flight, the system continuously monitors the heartbeat signal of the link data. If the heartbeat signal remains disconnected for more than a preset time threshold, the fiber optic cable is considered broken. For example, suppose a physical break occurs in a thin-diameter fiber optic cable due to violent drone maneuvers. In this case, the signal selection module intercepts the disconnection and triggers link disconnection protection on the drone's flight controller. The drone enters a hovering waiting state, which can be configured via the ground control terminal, preset to 15 seconds (the current attitude can be maintained by sending back remote control data packets). The system enters a 15-second preset waiting time threshold. If the connection is restored within 15 seconds due to a loose connector or a momentary interruption in the optical signal, the system determines it as a false disconnection and continues to use the fiber optic link to complete the reconnection task. This 15-second buffer anti-shake mechanism effectively prevents control malfunctions caused by ping-pong switching of the link.

[0048] During flight, the system monitors the fiber optic link data heartbeat signal in real time at a 1-second interval. If no heartbeat signal is detected for one consecutive second, the fiber optic link is deemed abnormal. Assuming a brief signal interruption occurs due to a sharp bend in the cable caused by drone maneuvering, the signal selection module intercepts the disconnection. The drone immediately ignores any erroneous signals from the ground that may be caused by interference and triggers a preset joystick return command to the flight control system. Upon triggering the hover command, the drone does not immediately stop abruptly but maintains its current instantaneous attitude, relying on the flight control's highly reliable algorithm to achieve a smooth dynamic transition from maneuvering to a stable hovering attitude.

[0049] Simultaneously, the system enters a hovering waiting state and starts a preset timer for 15 seconds (this preset time threshold can be customized through options set in the ground-based APP; 15 seconds is chosen because false disconnections usually recover after stress release within a few seconds). If the signal recovers within 15 seconds, the system determines it as a false disconnection and continues to use the fiber optic link.

[0050] Link takeover and deep self-rescue mechanism: If no fiber optic signal is received after 15 seconds, the system confirms a physical disconnection. The STM32 main control chip immediately outputs levels through the SBUS_CTL and NET_CTL pins to control the channel selection module to perform an instantaneous switch. Since the dual-link signals are already in a synchronous hot standby state under the action of the time synchronization clock, this switch is only equivalent to the closing transition of the underlying physical switch, without the need to re-establish the wireless network handshake, and the flight control is instantly taken over by the wireless link.

[0051] An extreme scenario exists: due to the long fiber optic cable distance, the location where the drone experiences fiber optic disconnection is beyond the effective coverage radius of the handheld ground station's wireless module. That is, even after switching channels, a wireless link signal cannot be found. In this case, the invention triggers a deep self-rescue logic: the drone activates safety protection and returns to its original heading towards the takeoff point. During the return journey to close the physical distance, the signal selection module continuously searches for a wireless link transmission signal. Once a connection is successfully established en route, the drone immediately returns to wireless control and can continue or abort the mission; if no connection is established, it returns to above the takeoff point and lands in place, ensuring the aircraft is not lost.

[0052] Example 3: The system architecture of the present invention also has high backward compatibility and meets different load requirements.

[0053] like Figure 2 As shown (in standalone fiber optic mode), when the UAV is not equipped with a wireless data link device to add other payloads, the second set of interfaces of the signal selection module is left floating. As long as the fiber optic link is normal, the system can work stably, realizing UAV control and data backhaul under standalone fiber optic channel connection.

[0054] like Figure 3 As shown (in standalone wireless mode), when the UAV performs routine short-range missions without a fiber optic cable, the first set of interfaces of the signal selection module is left unattended. After the UAV takes off, the signal selection module determines that there is no signal on the fiber optic cable and directly locks onto the wireless link input for forwarding, transmitting the modulated and demodulated image, data, and telemetry signals, thereby achieving channel connectivity for the standalone wireless link.

[0055] In summary, the communication scheme combining optical fiber and wireless links provided by this invention has extremely high adaptability, integrating the strong anti-interference capability of optical fiber with the physical freedom of wireless. Through the combination of intelligent routing and flight control self-rescue logic, it achieves highly reliable operation of UAVs in complex electromagnetic environments and harsh terrain conditions.

[0056] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A UAV communication method that combines fiber optic and wireless links, applied to a communication system including a ground terminal and a UAV terminal, characterized in that, The drone terminal has a built-in signal selection module, and the method includes the following steps: S10. Before the UAV takes off, connect the optical fiber communication link and the wireless communication link between the ground terminal and the UAV terminal, and during the flight, the signal of the wireless communication link and the signal of the optical fiber communication link are kept in a synchronized output state based on the time synchronization clock built into the signal selection module. S20. During the flight of the UAV, the signal selection module prioritizes receiving the signal transmitted by the optical fiber communication link and forwards the signal to the UAV flight controller to execute the flight mission; S30. Monitor the heartbeat signal of the optical fiber communication link in real time. If the heartbeat signal is not detected within a specified time, determine that the optical fiber communication link is abnormal, control the UAV to automatically ignore any signal from the ground end, and trigger the execution of the preset joystick return command to control the UAV to enter the hovering waiting state, and start the preset time threshold timing at the same time. S40. If the fiber optic communication link fails to reconnect within a preset time threshold, the signal selection module will instantly switch the communication channel to the wireless communication link that is already in a synchronized output state, and the wireless communication link will take over the control of the UAV.

2. The UAV communication method using a combination of optical fiber and wireless link according to claim 1, characterized in that, Following step S40, a wireless link anomaly protection step is also included: If the flight distance of the UAV exceeds the effective communication distance of the wireless communication link, resulting in the loss of wireless signal, the UAV is controlled to return to the takeoff point along the flight path; During the UAV's return flight, the signal selection module continuously searches for signals on the wireless communication link; If the UAV searches for and reconnects to the wireless communication link signal during flight, it resumes the follow-up mission; if the wireless communication link signal is not found, the UAV returns to its starting point and lands in place.

3. The UAV communication method using a combination of optical fiber and wireless link according to claim 1, characterized in that, In step S30: The preset time threshold is 15 seconds, configured via the ground terminal; At the moment the hovering wait is triggered, the UAV maintains an instantaneous attitude and relies on the UAV flight control algorithm to achieve a smooth attitude transition from the current maneuver to a stable hovering state. If the signal of the optical fiber communication link is restored within the preset time threshold of 15 seconds, the anomaly is determined to be a false disconnection caused by a large-angle bend in the optical fiber. The signal selection module then reconnects the optical fiber communication link, restores the signal at the ground end, and controls the UAV to complete the reconnection task.

4. The UAV communication method using a combination of optical fiber and wireless link according to claim 1, characterized in that, The signal selection module is internally configured with a main control chip, an Sbus channel selection module, and a network port channel selection module. In step S40, the signal selection module switches the communication channel to the wireless communication link in the following way: the main control chip controls the Sbus channel selection module and the network port channel selection module to switch channels, so that the signal of the Sbus port and the signal of the network port switch from the optical fiber communication link to the wireless communication link at the same time.

5. The UAV communication method using a combination of optical fiber and wireless link according to claim 4, characterized in that: The ground terminal and the UAV terminal communicate via the Sbus port for remote control signal transmission, and via the network port for image and data signal transmission.

6. The UAV communication method using a combination of optical fiber and wireless link according to claim 1, characterized in that, The method also supports a single-link compatible operating mode: When the UAV is not connected to any signal of the wireless communication link, the signal selection module locks the use of the optical fiber communication link for control and data transmission. When the UAV is not connected to any signal of the fiber optic communication link, the signal selection module locks the wireless communication link for control and data transmission.

7. A drone communication system that combines fiber optic and wireless links, for implementing the method as described in any one of claims 1-6, characterized in that, The system includes: a ground terminal and a drone terminal; The ground terminal includes: a handheld ground control station with a built-in wireless communication link module, and a ground-end optical transceiver connected to the handheld ground control station; The UAV terminal includes: an airborne optical transceiver, an aircraft-side data link, a signal selection module, and a UAV flight controller; The output of the airborne optical transceiver and the output of the aircraft data link are both connected to the input of the signal selection module, and the output of the signal selection module is connected to the input of the UAV flight controller.

8. The system according to claim 7, characterized in that, The signal selection module is externally configured with a first input interface group, a second input interface group and an output interface group, and internally configured with a time synchronization clock. The first input interface group is connected to the air-to-air optical transceiver and is used to receive optical fiber communication link signals; The second input interface group is connected to the aircraft-side data link and is used to receive wireless communication link signals; The output interface group is connected to the input terminal of the UAV flight controller and is used to output a composite signal from a single source to the UAV flight controller. The first input interface group, the second input interface group, and the output interface group each include an Sbus signal channel interface and a network port signal channel interface. The time synchronization clock is used to control the optical fiber signal received by the first input interface group and the wireless signal received by the second input interface group to maintain time axis synchronization within the signal selection module, so as to provide instantaneous output during channel switching.

9. The system according to claim 8, characterized in that, The first input interface group consists of S-Bus port 1 and network port 1; the second input interface group consists of S-Bus port 2 and network port 2; and the output interface group consists of S-Bus output port and network output port. The corresponding interface of the airborne optical transceiver is connected to the Sbus port 1 and network port 1 of the signal selection module, and the corresponding interface of the aircraft data link is connected to the Sbus port 2 and network port 2 of the signal selection module. The S-Bus output port of the signal selection module is connected to the corresponding S-Bus input port of the UAV flight controller, and the network output port of the signal selection module is connected to the corresponding network input port of the UAV flight controller.

10. The system according to claim 9, characterized in that, The internal circuit of the signal selection module consists of a main control chip, an Sbus switching chip, and a network port switching chip. The main control chip is an STM32G030K8T6 microcontroller, whose pins output SBUS_CTL control signal and NET_CTL control signal; The Sbus switching chip uses an SN74LVC1G3157 multiplexing chip. Its control pin receives the SBUS_CTL control signal. The two input pins of the Sbus switching chip are connected to Sbus port 1 and Sbus port 2 respectively, and its output pin is connected to the Sbus output port. The network port switching chip uses the PI3L500-A network switching chip. Its gating control pin receives the NET_CTL control signal. The two sets of network signal input pins included in the network port switching chip are respectively connected to network port 1 and network port 2, and the one set of network signal output pins included in the chip are connected to the network port output port.

Images