Unmanned aerial vehicle energy supply system and method based on fiber optic cable

Abstract

The present application relates to the technical field of tethered unmanned aerial vehicle, and discloses an unmanned aerial vehicle energy supply system and method based on optical fiber cable, comprising: an energy supply station arranged on the ground or carried on a mother ship; a light flexible high-energy laser transmission optical cable, the first end of which is optically coupled with the energy supply station; and an unmanned aerial vehicle, which is provided with an optoelectronic conversion unit, the second end of the light flexible high-energy laser transmission optical cable being releasably physically connected with the optoelectronic conversion unit, for receiving a high-energy laser beam transmitted through the light flexible high-energy laser transmission optical cable, and converting the high-energy laser beam into electric energy through the optoelectronic conversion unit to provide all or part of the electric power required for flight and task load; through the laser-electric energy conversion mode based on the light flexible high-energy laser transmission optical cable, the decoupling of the hovering height and the operation radius of the unmanned aerial vehicle is realized, the restriction of the self-weight of the on-board battery on the flight performance is eliminated, and the unmanned aerial vehicle can still maintain stable hovering and long-time hovering in a complex airflow environment.

Description

Technical Field

[0001] This invention relates to the field of tethered unmanned aerial vehicle (UAV) technology, and in particular, to a power supply system and method for UAVs based on optical fiber cables. Background Technology

[0002] With the widespread application of drone technology in the civilian sector, extremely high demands are placed on the endurance of drones for long-term operational scenarios such as large-area continuous surveillance, emergency communication relay, geographic mapping, and environmental monitoring. Tethered drone technology connects the drone to a ground support platform via cables, aiming to provide the drone with continuous ground energy replenishment, thereby overcoming the limitations of onboard battery capacity and achieving theoretically unlimited endurance.

[0003] However, existing tethered drone systems generally use power cables (usually copper core cables) as the energy transmission medium, which has the following insurmountable technical drawbacks in practical applications: First, the trade-off between cable weight and transmission loss limits operating altitude and distance. To transmit sufficient high-power electrical energy to power the drone, the power cable needs a large cross-sectional area, resulting in a high unit weight and thick diameter. For tethering heights in the hundreds of meters range, the cable itself can weigh several kilograms, severely impacting the drone's payload and significantly increasing lift consumption. Simultaneously, as the transmission distance increases, the resistance loss of the metal cable rises sharply, further limiting the drone's operating radius and hovering altitude.

[0004] Secondly, electromagnetic compatibility and anti-interference capabilities are insufficient. When a large current passes through a power cable, it generates a strong electromagnetic field in the surrounding area, which may not only interfere with the UAV's own electronic compass, navigation system, and mission payload (such as high-definition image transmission equipment), but may also cause electromagnetic pollution to surrounding precision electronic equipment, reducing the system's operational reliability in complex electromagnetic environments.

[0005] Secondly, the system's deployment flexibility and mobility are limited. Due to the high rigidity and large bending radius of power cables, the deployment and take-up mechanisms are bulky and cumbersome, resulting in slow attitude adjustment response of drones during dynamic operations, making it difficult to adapt to application scenarios requiring rapid deployment and high mobility.

[0006] To address the issue of battery life, free-space laser wireless power transmission technology has been proposed. This technology uses a laser beam to transmit energy through the air, eliminating the need for cables. However, its transmission efficiency is highly susceptible to atmospheric turbulence, fog, rain, and other weather conditions. Furthermore, it suffers from problems such as difficulty in aligning the transmitter and receiver, high risk of high-power laser divergence, and poor system stability, making it difficult to meet the continuous and reliable power supply requirements of industrial applications. Summary of the Invention

[0007] This invention provides a power supply system and method for unmanned aerial vehicles (UAVs) based on optical fiber cables. By injecting high-energy laser energy into lightweight flexible optical fibers to replace traditional metal power cables for wired transmission, the low-loss characteristics of optical transmission and the lightweight nature of the medium overcome the physical contradiction between cable weight and power transmission capacity. This solves the technical problems of existing tethered UAVs, such as limited flight altitude, reduced payload capacity, poor electromagnetic compatibility, and high susceptibility to environmental interference and insufficient safety of free-space laser power supply, caused by excessive cable weight.

[0008] According to one aspect of the present invention, a power supply system for unmanned aerial vehicles (UAVs) based on optical fiber and cable is provided, comprising: a power supply station, deployed on the ground or mounted on a mothership, for generating and outputting a high-energy laser beam as an energy carrier; a lightweight flexible high-energy laser transmission optical cable, the first end of which is optically coupled to the power supply station, for guiding the high-energy laser beam for long-distance energy transmission through a low-loss optical path and avoiding interference from electromagnetic radiation to the transmission channel; and a UAV equipped with a photoelectric conversion unit, the photoelectric conversion unit being physically releasably connected to the second end of the lightweight flexible high-energy laser transmission optical cable, for receiving the high-energy laser beam transmitted through the lightweight flexible high-energy laser transmission optical cable and converting it into electrical energy through the photoelectric conversion unit to provide all or part of the power required for flight and mission payload; through the laser-to-electricity conversion mode based on the lightweight flexible high-energy laser transmission optical cable, the hovering altitude and operating radius of the UAV are decoupled, and the constraint of the onboard battery weight on flight performance is eliminated, ensuring that the UAV can maintain stable hovering and long-term loitering in complex airflow environments.

[0009] Furthermore, the lightweight flexible high-energy laser transmission optical cable adopts single-clad fiber, double-clad fiber, triple-clad fiber, hollow-core photonic crystal fiber or anti-resonant hollow-core fiber, and / or the lightweight flexible high-energy laser transmission optical cable includes a fiber core for light guiding, a cladding wrapped around the fiber core, a coating wrapped around the cladding, and a high-strength flexible protective layer wrapped around the coating; the unit length mass of the lightweight flexible high-energy laser transmission optical cable is less than 30 grams / meter, and the minimum bending radius is less than 20 centimeters; according to the payload capacity and operating radius requirements of the UAV, the length of the lightweight flexible high-energy laser transmission optical cable is set to 10 meters-1000 meters.

[0010] Furthermore, the high-strength flexible protective layer is physically reinforced with materials such as glass fiber and Kevlar to improve tensile strength, and it is much lighter than the cable. The weight of the optical cable is greatly reduced, which can greatly improve flight altitude, maneuverability and operating radius.

[0011] Furthermore, the lightweight, flexible, high-energy laser transmission optical cable is an unarmored optical cable with no internal metal. It is reinforced with materials such as Kevlar and fiberglass to improve tensile strength, resulting in a very light weight per unit length.

[0012] Furthermore, the coating layer provides mechanical protection, tensile strength, and weather resistance; the high-strength flexible protective layer is reinforced with aramid fibers, high-strength polyethylene fibers, etc., and coated with wear-resistant and UV-resistant polymer materials; the design goal of the lightweight flexible high-energy laser transmission optical cable is to achieve a balance between high strength and lightweight, making its unit length mass much smaller than that of copper cables of the same power level.

[0013] Furthermore, in situations where weight requirements are stringent (such as long-distance tethering, line-of-sight operations, etc.), lightweight, flexible, high-energy laser transmission cables can also be made from disposable fiber optic tubs of fiber-optic guided drones, eliminating the need for a high-strength flexible protective layer on the outside of the fiber.

[0014] Furthermore, within the coating layer or high-strength flexible protective layer of the lightweight flexible high-energy laser transmission optical cable, one or more communication optical fibers for transmitting communication signals are integrated to form a composite optical cable that transmits both energy and signals.

[0015] Furthermore, the drone is equipped with a tethering interface, which is physically fixed to the output port of a lightweight, flexible, high-energy laser transmission cable via a tethering mechanism. The tethering interface adopts at least one of QBH, FC, or SMA.

[0016] Furthermore, the tethering mechanism includes a connector located at the output port of the lightweight flexible high-energy laser transmission cable, and a docking seat located on the tethering interface of the UAV; the connector and the docking seat achieve rapid connection and disconnection through one or more of the following methods: magnetic adsorption, mechanical snap-fit, or electromagnetic lock, and ensure stable alignment of the optical fiber path of the lightweight flexible high-energy laser transmission cable with the optical input port of the photoelectric conversion unit in the connected state.

[0017] Furthermore, in order to achieve reliable and rapid connection and optical path docking between the UAV and the lightweight flexible high-energy laser transmission optical cable, a dedicated tethering mechanism was designed. The tethering mechanism includes: a connector, which is fixed to the output port of the lightweight flexible high-energy laser transmission optical cable and contains a precision mating port inside to protect the fiber end face and realize optical path docking; and a docking seat, which is fixed to the tethering interface of the UAV and contains an optical interface that matches the connector, which can directly guide the high-energy laser beam output from the fiber into the photoelectric conversion unit inside the UAV.

[0018] Furthermore, the connection between the connector and the docking seat can be achieved by using the magnetic adsorption of permanent magnets and ferromagnetic materials to achieve rapid initial alignment and fixation, supplemented by mechanical buckles for secondary locking, ensuring a stable connection during high-maneuverability flight; the optical channels inside the connector and docking seat adopt a self-aligning design to ensure automatic alignment of the optical path during connection.

[0019] Furthermore, the photoelectric conversion unit includes: an optical coupling interface for receiving a high-energy laser beam from the output port of a lightweight, flexible, high-energy laser transmission optical cable; a high-efficiency photoelectric converter, which is a multi-junction photovoltaic cell or a vertical-cavity surface-emitting laser array optimized for laser wavelength, for converting light energy into electrical energy and achieving a photoelectric conversion efficiency of at least 50%; and a heat dissipation component, thermally connected to the high-efficiency photoelectric converter, for dissipating the heat generated during the conversion process.

[0020] Furthermore, the optical coupling interface includes a beam homogenizing element; a high-energy laser beam from the optical fiber enters the optical coupling interface through the docking seat and then uniformly illuminates the high-efficiency photoelectric converter.

[0021] Furthermore, the high-efficiency photoelectric converter is preferably a multi-junction gallium arsenide photovoltaic cell optimized for laser wavelength, with a photoelectric conversion efficiency exceeding 50%.

[0022] Furthermore, the heat dissipation components employ heat pipes or vapor chambers, combined with the drone's outer shell for heat dissipation.

[0023] Furthermore, the photoelectric conversion unit also includes a power management module, which is electrically connected to the high-efficiency photoelectric converter. The power management module includes a maximum power point tracking circuit and a DC-DC conversion circuit, which are used to optimize power output and distribute the optimized power to the UAV's flight control system, power system, and mission payload.

[0024] Furthermore, the optimized power is distributed to the drone's flight control system, power system, and mission payload on demand. The power management module monitors and coordinates the power required by the drone and payload, whether the battery is fully charged, and whether power consumption has increased.

[0025] Furthermore, the task load includes lighting sources, communication modules, etc.

[0026] Furthermore, the power management module manages the electrical energy output from the photovoltaic cells and adjusts it to the different voltages required by various UAV systems (such as flight control, ESC, and mission payload) via a DC-DC conversion circuit. Because the energy source is continuous and stable, the power management module can optimize the efficiency of the entire power system.

[0027] Furthermore, it also includes an optical fiber winding and unwinding management device, which is set at the location of the power supply station, on an independent tethered tower, or mounted on a drone, and is used to automatically wind up and unwind and control the tension of the lightweight, flexible, high-energy laser transmission optical cable during drone take-off, landing, or flight.

[0028] Furthermore, the fiber optic winding and unwinding management device includes a reel, a drive mechanism, a tension sensor, and a controller; the tension sensor monitors the tension of the lightweight, flexible, high-energy laser transmission cable in real time, and the controller controls the drive motor to adjust the winding and unwinding speed of the cable based on the tension data and the distance and speed information of the UAV, so as to maintain the preset tension range.

[0029] Furthermore, relying on the tension sensor (stress sensor) in the fiber optic winding and unwinding management device and setting a preset threshold range, when the tension (stress) on the lightweight flexible high-energy laser transmission optical cable is greater than the preset threshold range, the drive motor drives the reel to perform the unwinding operation; when the tension (stress) on the lightweight flexible high-energy laser transmission optical cable is less than the preset threshold range, the drive motor drives the reel to perform the winding operation.

[0030] Furthermore, the drive mechanism employs a servo motor.

[0031] Furthermore, when the drone takes off, the drive mechanism actively releases the cable; when hovering or maneuvering, the controller dynamically adjusts the release and retraction speed based on feedback from the tension sensor and position and / or speed information from the drone, so that the optical fiber maintains appropriate suspension tension and avoids pulling too tightly or dragging on the ground too loosely.

[0032] Furthermore, the design of the reel must ensure that the optical fiber is wound in an arc greater than its minimum bending radius to prevent damage.

[0033] Furthermore, the power supply station includes a high-power continuous laser, a laser power control and safety module, and an initial coupling optical system; the high-power continuous laser adopts fiber lasers, semiconductor lasers, solid-state lasers, etc.; the laser power control and safety module is configured to immediately send an emergency stop signal or a power reduction signal to the power supply station to cut off or reduce the laser output when a break, disconnection, or signal abnormality is detected in the lightweight flexible high-energy laser transmission optical cable; the initial coupling optical system efficiently couples the laser output from the high-power continuous laser into the high-energy laser and transmits it to the input port of the lightweight flexible high-energy laser transmission optical cable.

[0034] Furthermore, the safety mechanisms of the laser power control and safety module include, but are not limited to: cutting off the laser when the optical cable breaks; reducing power when the optical cable tension is too high; reducing power when the photoelectric converter overheats; reducing power when the drone battery is nearly fully charged; and increasing laser output power when power consumption increases. The logic is to ensure the safe and stable operation of the system.

[0035] Furthermore, the laser power control and safety module is responsible for the startup and power regulation of the high-power continuous laser, and integrates multiple safety protections such as emergency stop of output, high and low temperature alarms, and connection loosening alarms. It issues alarms when encountering over-temperature or over-limit conditions, and provides emergency stop of output in case of emergencies. For example, when a fiber optic break detection sensor (such as a photodetector monitoring backlight) or a communication link detects a connection abnormality, the laser power control and safety module can quickly send an emergency stop signal to the system, cutting off laser output within milliseconds to ensure system safety.

[0036] Furthermore, the laser power control and safety module can quickly send an emergency stop signal to the system, cutting off the laser output within milliseconds. Specifically, a photodetector is used to detect the backlight. When the backlight suddenly increases, it indicates a change in the transmission link. The control circuit immediately outputs an emergency stop signal to the high-power continuous laser, and the high-power continuous laser stops emitting light.

[0037] Furthermore, the initial coupling optical system includes a precision adjustment frame and a focusing lens.

[0038] Furthermore, high-power continuous lasers employ semiconductor lasers with output power ranging from hundreds of watts to thousands of watts and an output wavelength of 808 nm, or fiber lasers with output power ranging from hundreds of watts to thousands of watts and a wavelength of 1080 nm, which matches the response band of commonly used high-efficiency photovoltaic cells.

[0039] According to another aspect of the present invention, a method for powering a drone based on optical fiber and cable is also provided. The method employs the aforementioned optical fiber and cable-based drone power supply system and includes the following steps: S1, a lightweight flexible high-energy laser transmission cable output port is fixedly connected to the drone's tethering interface via a tethering mechanism, establishing an optical link from the power supply station to the drone; S2, the high-power continuous laser at the power supply station is activated, and the high-energy laser beam is transmitted to the drone's photoelectric conversion unit via the lightweight flexible high-energy laser transmission cable; S3, the photoelectric conversion unit converts the received laser energy into DC power in real time, and after processing by the power management module, directly drives the drone's motors and flight control system; S4, during drone flight operations, the optical fiber winding and unwinding management device synchronously winds up and unwinds the lightweight flexible high-energy laser transmission cable according to the drone's flight status, maintaining it in a suitable suspension state; S5, when the drone needs to be recovered or the mission ends, it is controlled to fly back to the vicinity of the power supply station, and the connection between the lightweight flexible high-energy laser transmission cable and the drone is disconnected via the tethering mechanism.

[0040] Furthermore, the method for powering unmanned aerial vehicles (UAVs) based on optical fiber cables specifically includes: preparation and docking: the UAV lands or hovers in the docking area near the power supply station; the operator or automated robotic arm connects and locks the connector at the output port of the high-energy laser transmission optical cable to the docking seat on the UAV; startup and takeoff: the power supply station is powered on, and the high-power continuous laser starts at low power; the laser is transmitted to the UAV through optical fiber and received by the photoelectric conversion unit; after the power management module confirms that the power supply is stable, the UAV starts its motor and takes off under the synchronous cable release control of the optical fiber winding and unwinding management device; continuous operation: the UAV flies to the target area to perform the mission; during this period, the power supply station continuously provides laser energy, enabling the UAV to achieve "unlimited flight"; the optical fiber winding and unwinding management device adjusts the optical fiber status in real time according to the movement of the UAV; recovery and disconnection: after the mission ends, the UAV returns to the docking area and lands; the power of the high-power continuous laser is reduced or turned off; the connection of the tethering mechanism is disconnected, and the optical fiber winding and unwinding management device retracts the high-energy laser transmission optical cable onto the reel.

[0041] The present invention has the following beneficial effects: 1. Decoupling of cable weight and lift load based on medium innovation: The use of lightweight, flexible, high-energy laser transmission optical cable, taking advantage of the extremely low density of optical fiber compared to metal conductors, significantly reduces the mass per unit length of cable. This allows for a substantial reduction in the static consumption and dynamic disturbance of the tethered cable on the lift of the UAV while maintaining or even improving energy transmission capabilities. When the UAV is tethered, its payload capacity is no longer excessively squeezed by the heavy cable weight, thus achieving decoupling between hovering altitude and operating radius. In other words, as the operating altitude increases, the nonlinear constraint of the increase in cable weight on flight performance is weakened, ensuring stable hovering at high altitudes.

[0042] 2. High-efficiency transmission and anti-interference based on optical transmission mechanism: The power station outputs a high-energy laser beam and guides it through a low-loss optical path inside the optical cable; the transmission process of photons does not involve the directional movement of free electrons, so the energy attenuation rate during long-distance transmission is much lower than that of traditional power cables; since the laser energy is confined in the total internal reflection path of the optical fiber core, combined with the structural shielding of the optical cable, the external radiation of the electromagnetic field is completely blocked; the system has extremely high overall energy transmission efficiency, and the transmission channel naturally has electromagnetic compatibility (EMC), ensuring the purity of the data link of the mission payload.

[0043] 3. Reconstruction of airborne energy architecture based on photoelectric conversion: The UAV is equipped with a photoelectric conversion unit to convert the received light radiation energy into electrical energy; the function of energy storage components is separated from the energy receiving function, and the airborne end only needs to retain the real-time conversion and buffering module; the UAV can change from carrying energy to extracting energy through a pipeline, which greatly optimizes the power-to-weight ratio of the platform, enabling medium-sized UAVs to perform long-endurance heavy-load missions, and avoiding the lifespan degradation and thermal runaway risks caused by battery charge-discharge cycles.

[0044] 4. Environmental adaptability and operational reliability based on physical connection characteristics: The optical cable forms a releasable physical connection with the power station and the UAV. This wired connection mode establishes a defined physical channel and does not rely on the atmospheric medium as a transmission carrier. The releasable characteristic gives the UAV the freedom to detach during emergency avoidance or mission changes, taking into account both the durability of tethered operations and survivability in emergencies.

[0045] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0046] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the structure of a drone power supply system based on optical fiber and cable according to a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a lightweight, flexible, high-energy laser transmission optical cable according to a preferred embodiment of the present invention; Figure 3 This is a schematic diagram of the connection structure between the tethering mechanism and the photoelectric conversion unit in a preferred embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the optical fiber winding and unwinding management device according to a preferred embodiment of the present invention; Figure 5 This is a flowchart illustrating the steps of a preferred embodiment of the UAV power supply method based on optical fiber and cable according to the present invention.

[0047] Legend: 100. Power supply station; 110. High-power continuous laser; 120. Laser power control and safety module; 130. Initial coupling optical system; 200. Lightweight flexible high-energy laser transmission optical cable; 201. Input port; 202. Output port; 210. Fiber core; 220. Cladding; 230. Coating layer; 240. High-strength flexible protective layer; 250. Communication optical fiber; 300. Tethering mechanism; 310. Connector; 320. Docking seat; 400. Unmanned aerial vehicle (UAV); 401. Tethering interface; 410. Photoelectric conversion unit; 411. Optical coupling interface; 412. High-efficiency photoelectric converter; 413. Heat dissipation component; 420. Power management module; 500. Fiber optic winding and unwinding management device; 510. Reel; 520. Drive mechanism; 530. Tension sensor; 540. Controller. Detailed Implementation

[0048] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0049] like Figure 1As shown, the UAV power supply system based on fiber optic cable in this embodiment includes: a power supply station 100, deployed on the ground or mounted on a mothership, used to generate and output a high-energy laser beam as an energy carrier; a lightweight flexible high-energy laser transmission optical cable 200, with its first end optically coupled to the power supply station 100, used to guide the high-energy laser beam for long-distance energy transmission through a low-loss optical path and avoid interference from electromagnetic radiation to the transmission channel; and a UAV 400, equipped with a photoelectric conversion unit 410, which is connected to the lightweight flexible high-energy laser transmission optical cable 200. The second end of 00 can release the physical connection to receive the high-energy laser beam transmitted through the lightweight flexible high-energy laser transmission cable 200, and convert it into electrical energy through the photoelectric conversion unit 410 to provide all or part of the power required for flight and mission payload; through the laser-to-electric energy conversion mode based on the lightweight flexible high-energy laser transmission cable 200, the hovering height and operating radius of the UAV 400 are decoupled, and the constraint of the onboard battery weight on flight performance is eliminated, ensuring that the UAV 400 can still maintain stable hovering and long-term loitering in complex airflow environments. This invention relates to a UAV power supply system based on optical fiber cables. It replaces the metal power cables in the prior art with a lightweight, flexible, high-energy laser transmission optical cable 200. By utilizing the extremely low density of optical fiber media (such as those mainly composed of quartz glass and polymer composite materials) compared to metal conductors (copper / aluminum), the mass per unit length of cable is significantly reduced. This allows for a substantial reduction in the static consumption and dynamic disturbance of the lift of the UAV 400 by the tethered cable while maintaining or even improving energy transmission capabilities. When the UAV 400 is tethered, its payload capacity is no longer excessively squeezed by the weight of the cable itself, thereby decoupling the hovering altitude and the operating radius. That is, when the operating altitude is increased, the nonlinear constraint of the increase in cable weight on flight performance is weakened, ensuring stable hovering at high altitudes. The power station 100 outputs a high-energy laser beam, which is guided by a low-loss optical path inside the optical cable. The transmission process of photons does not involve the directional movement of free electrons, thus eliminating Joule heat loss and impedance loss caused by the skin effect. This results in a much lower energy attenuation rate during long-distance transmission compared to traditional power cables. Since the laser energy is confined to the total internal reflection path of the fiber core, combined with the structural shielding of the optical cable, the external radiation of the electromagnetic field is completely blocked. The system has extremely high overall energy transmission efficiency, and the transmission channel naturally possesses electromagnetic compatibility (EMC). It will not cause co-channel interference to the UAV 400's own magnetic compass and radio link, nor will it be affected by the intrusion of complex external electromagnetic environments, ensuring the purity of the data link for the mission payload.The UAV 400 is equipped with a photoelectric conversion unit 410, which converts received light radiation energy into electrical energy. This separates the function of the energy storage element (battery) from the energy receiving function, requiring only the real-time conversion and buffering modules on the airborne end, eliminating the need to bear the weight of the large chemical battery. This eliminates the constraint of the airborne battery's weight on flight performance, allowing the UAV 400 to switch from carrying energy to extracting energy through a conduit, greatly optimizing the platform's power-to-weight ratio. This enables medium-sized UAVs to perform long-endurance, heavy-load missions and avoids the lifespan degradation and thermal runaway risks associated with battery charge-discharge cycles. A releasable physical connection is formed between the optical cable, the power supply station 100, and the UAV 400. This wired connection establishes a defined physical channel, independent of the atmospheric medium as a transmission carrier. The stability of energy transmission is unaffected by refractive index changes due to weather conditions such as rain, fog, haze, and turbulence, solving the inherent alignment drift and attenuation fluctuation problems in free-space laser transmission. The releasable characteristic gives the UAV 400 the freedom to detach during emergency avoidance or mission changes, balancing the durability of tethered operations with survivability in unforeseen circumstances. This invention relates to a fiber optic cable-based UAV power supply system. Through a technical chain of "high-energy laser beam - fiber optic path - photoelectric conversion", it reconstructs the energy supply system of tethered UAVs. By utilizing the physical characteristics of optical transmission media, it simultaneously solves the technical problems of excessive cable weight limiting height, resistance loss limiting distance, and electromagnetic radiation interference with equipment in traditional tethered systems. While eliminating the constraints of onboard battery weight, it significantly improves operational reliability and platform maneuverability in complex environments, maximizing the energy supply efficiency of tethered UAVs during long-endurance missions.

[0050] like Figure 1 and Figure 2As shown, in this embodiment, the lightweight flexible high-energy laser transmission optical cable 200 adopts single-clad fiber, double-clad fiber, triple-clad fiber, hollow-core photonic crystal fiber, or anti-resonant hollow-core fiber, and / or the lightweight flexible high-energy laser transmission optical cable 200 includes a fiber core 210 for guiding light, a cladding 220 wrapped around the fiber core 210, a coating layer 230 wrapped around the cladding 220, and a high-strength flexible protective layer 240 wrapped around the coating layer 230; the unit length mass of the lightweight flexible high-energy laser transmission optical cable 200 is less than 30 grams / meter, and the minimum bending radius is less than 20 centimeters; according to the payload capacity and operating radius requirements of the UAV 400, the length of the lightweight flexible high-energy laser transmission optical cable 200 is set to 10 meters to 1000 meters. The lightweight, flexible, high-energy laser transmission optical cable 200 employs specific waveguide structures, including single-clad fiber, double-clad fiber, triple-clad fiber, hollow-core photonic crystal fiber, and anti-resonant hollow-core fiber. Different waveguide structures are optimized for specific wavelengths of laser transmission. Double-clad and triple-clad structures increase energy transmission density by expanding the pump light absorption area. Hollow-core photonic crystal and anti-resonant hollow-core fibers utilize the photonic bandgap effect or anti-resonant reflection principle to confine laser energy within air or low-refractive-index media, significantly reducing nonlinear effects (such as stimulated Brillouin scattering and stimulated Raman scattering) and material absorption loss, while simultaneously increasing the fiber's damage threshold. This allows the cable to safely and efficiently transmit higher power density laser energy, meeting the stringent input power requirements of medium-to-large-sized UAV platforms and preventing performance degradation or failure due to accumulated thermal effects. The optical cable consists of a fiber core 210 for guiding light, a cladding 220 wrapped around the fiber core 210, a coating layer 230 wrapped around the cladding 220, and a high-strength flexible protective layer 240 wrapped around the coating layer 230. Functional decoupling is achieved through a layered composite structure design. The waveguide structure formed by the fiber core 210 and the cladding 220 is responsible for constraining the laser light path and ensuring low-loss transmission. The coating layer 230 provides primary mechanical protection and resistance to micro-bending. The high-strength flexible protective layer 240 (such as one woven from high-performance fibers such as aramid fiber, ultra-high molecular weight polyethylene, or glass fiber) bears the main axial tensile force and radial compressive stress. While possessing excellent tensile strength, the optical cable maintains sufficient radial flexibility, enabling it to withstand the dynamic mechanical loads generated by UAV take-off and landing, attitude changes, and airflow disturbances, protecting the fragile internal waveguide structure from physical damage and ensuring the physical integrity of the energy transmission link.The unit length mass of the optical cable is limited to less than 30 grams per meter, and the minimum bending radius is less than 20 centimeters. The extremely low unit length mass directly reduces the static consumption of the cable's own weight on the lift of the UAV 400, and reduces the dynamic disturbance torque generated by the cable swinging in the wind. The extremely small minimum bending radius significantly reduces the bending stiffness and frictional resistance of the cable during the winding and unwinding process, reduces the negative impact of the tethering system on the flight performance of the UAV 400, and improves the maneuvering response speed and attitude stability of the UAV 400. At the same time, it allows the matching optical fiber winding and unwinding management device 500 to use a smaller size reel 510 and drive mechanism 520, improving the portability and rapid deployment capability of the entire system. The length of the optical cable can be configured within the range of 10 meters to 1000 meters according to the payload capacity and operational radius requirements of the UAV 400. By treating the cable length as a variable and matching it with the UAV 400's remaining lift margin and mission requirements, precise adaptation between the energy supply system and the flight platform is achieved. This maximizes the UAV 400's operational coverage radius and mission flexibility while ensuring safe flight, avoiding unnecessary weight increases due to excessive cable length or limited mission range due to excessively short cables. By defining the waveguide structure, layered composite construction, physical parameters, and configurable length of the optical cable, a lightweight and flexible transmission medium optimized for laser power supply to the UAV 400 was constructed. A special optical fiber structure ensures efficient and low-loss transmission of high-power lasers. Composite reinforcement and lightweight design resolve the contradiction between cable weight and mechanical compliance, thereby maximizing the flight performance and mission adaptability of the UAV 400 while ensuring safe and reliable energy transmission.

[0051] like Figure 1 and Figure 2As shown, in this embodiment, the high-strength flexible protective layer 240 is physically reinforced with materials such as glass fiber and Kevlar to improve tensile strength. It is also much lighter than a cable, significantly reducing the weight of the optical cable and thus greatly improving flight altitude, maneuverability, and operating radius. The high-strength flexible protective layer 240 is physically reinforced with high-strength, low-density fiber materials such as glass fiber and aramid fiber (i.e., Kevlar). The specific strength (strength to density ratio) of these materials is significantly higher than that of traditional metal materials (such as steel wire and aluminum wire), providing extremely high axial tensile modulus and breaking strength within a very small cross-sectional size. When subjected to dynamic tensile loads generated by the UAV 400's flight attitude changes, airflow disturbances, and the traction of the take-up and take-down mechanism, the optical cable can effectively resist plastic deformation and breakage risks, ensuring that the internal optical waveguide structure (fiber core 210 and cladding 220) is always in a low-stress state, maintaining the stability and long-term reliability of optical path transmission. The density of glass fiber and aramid fiber is much lower than that of copper conductors and steel armor layers used in traditional power cables. By replacing materials, the structural weight of the transmission medium is reduced. Without sacrificing mechanical strength, the mass per unit length of the optical cable is significantly reduced. The weight load of the tethered cable itself is greatly reduced as a proportion of the total lift of the UAV 400, thereby freeing up more payload capacity to carry mission equipment (such as optoelectronic pods and communication relay modules) or carry backup power. The reduced cable weight also reduces the inertial torque of the UAV 400 during three-dimensional maneuvers, significantly improving the aircraft's attitude response speed, hovering stability, and maneuverability in complex airflow environments, thereby expanding the radius of the mission and operational flexibility. The high-strength flexible protective layer 240, while employing rigid reinforcing fibers, maintains the flexible characteristics of the matrix material. The fiber material is composited onto the outer layer of the optical cable in a braided or spirally wound manner, providing both axial tensile stiffness and retaining radial bending freedom. The optical cable possesses an extremely small minimum bending radius and excellent fatigue bending resistance, allowing it to smoothly pass through the guide wheels and drum of the take-up and reel mechanism. This avoids cracking of the protective layer or breakage of internal optical fibers due to bending stress concentration, ensuring the mechanical reliability and service life of the system during repeated take-up and reel operations. The lightweight flexible high-energy laser transmission optical cable 200 uses an unarmored optical cable with no internal metal. It is reinforced with materials such as Kevlar and glass fiber to improve tensile strength, resulting in a very light weight per unit length. The coating layer 230 provides mechanical protection, tensile strength, and weather resistance; the high-strength flexible protective layer 240 is reinforced with aramid fibers, high-strength polyethylene fibers, etc., and coated with abrasion-resistant and UV-resistant polymer materials; the lightweight flexible high-energy laser transmission optical cable 200 is designed to achieve a balance between high strength and lightweight, making its unit length mass much smaller than that of copper cables of the same power rating. In applications with stringent weight requirements (such as long-distance tethering, line-of-sight operations, etc.), the lightweight flexible high-energy laser transmission optical cable 200 can also utilize the disposable fiber optic tub of the fiber-optic guided UAV 400, eliminating the need for the high-strength flexible protective layer 240 on the outside of the fiber.

[0052] like Figure 1 and Figure 2 As shown in this embodiment, one or more communication optical fibers 250 for transmitting communication signals are integrated within the coating layer 230 or the high-strength flexible protective layer 240 of the lightweight flexible high-energy laser transmission optical cable 200, forming a composite optical cable for co-transmission of energy and signals. The communication optical fiber 250 and the energy transmission optical fiber for transmitting high-energy laser are placed in the same optical cable sheath structure. Utilizing the compatibility of optical fiber communication and laser energy transmission at the physical layer (both based on optical fiber media), parallel transmission of energy flow and information flow is achieved in the same physical space. There is no need to configure a separate independent radio frequency communication antenna and feeder system for the UAV 400, nor is it necessary to lay additional metal communication cables. This significantly simplifies the electrical interface design and wiring complexity between the UAV 400 and its ground control station, reduces external protrusions and aerodynamic drag of the aircraft, and improves the integration and compactness of the system. The communication fiber optic cable 250 transmits optical signals, not electrical signals. The fiber optic medium possesses insulating and electromagnetic shielding properties, making it unaffected by changes in external electromagnetic fields and preventing the radiation of electromagnetic signals. This completely avoids the strong electromagnetic interference generated by high-power currents in traditional tethered cables, while also preventing the impact of complex external electromagnetic environments on control signals and image data errors. The non-radiative nature of fiber optic transmission makes communication content difficult to intercept wirelessly, greatly enhancing the confidentiality and anti-interception capabilities of UAV 400 remote control, telemetry, and mission data transmission. It is particularly suitable for operational scenarios with high information security requirements. The communication fiber optic cable 250 is fixed at a specific location around the power transmission fiber (within the coating layer 230 or the high-strength flexible protective layer 240). The composite optical cable, as a whole, withstands tension and bending, and the relative positions and physical states of the internal fiber units remain highly consistent. This avoids signal interruptions, attenuation fluctuations, or physical damage caused by wind swaying, tangling, or friction with the aircraft, ensuring the physical stability and transmission reliability of the communication link under high-dynamic flight attitudes and reducing flight safety risks caused by improper cable management. Although the communication fiber 250 and the power transmission fiber coexist in the same cable, they are independent in the wavelength dimension. Wavelength division multiplexing technology can be used to transmit signal light (for communication) and pump light (for power transmission) of different wavelengths simultaneously in the same fiber, or they can be carried separately in different fibers. Without increasing the physical volume and weight of the optical cable, the huge available bandwidth resources of the optical fiber are fully utilized, providing sufficient communication capacity for tasks with high bandwidth requirements (such as high-definition video backhaul and massive data download), and realizing a simultaneous leap in energy supply and information exchange capabilities.

[0053] like Figure 1 and Figure 3As shown, in this embodiment, the UAV 400 is provided with a tethering interface 401. The tethering interface 401 is physically fixedly connected to the output port 202 of the lightweight flexible high-energy laser transmission optical cable 200 via a tethering mechanism 300. The tethering interface 401 adopts at least one of QBH, FC, or SMA standard optical connectors. These standardized fiber optic connectors (such as FC type) or laser transmission connectors (such as QBH type) are all precision machined and tolerance controlled, which can ensure that the fiber end face or lens group in the plug and socket achieves coaxial alignment within the micron level. This reduces the optical axis offset loss caused by manual alignment error or mechanical vibration, and ensures that the high-energy laser beam output from the optical cable can enter the photoelectric conversion unit 410 inside the UAV 400 with extremely low insertion loss, thereby maintaining the high transmission efficiency of the entire power supply link. The tethering interface 401 forms a releasable physical fixed connection with the output port 202 of the optical cable via the tethering mechanism 300. Standardized connectors are usually equipped with bayonet type (such as QBH), threaded type (such as FC), or quick-lock type (such as SMA) mechanical locking structures. Before performing a mission, the UAV 400 can achieve a rapid connection with the power supply station 100 in seconds. In case of an emergency or when the mission ends, it can achieve a quick one-click disconnection. This plug-and-play feature significantly shortens the system's deployment preparation time and withdrawal time, improves the operational flexibility of the UAV 400 in emergency response scenarios, and gives the UAV 400 the ability to escape from cable constraints and switch to free flight mode when necessary. The tethering interface 401 defines a specific industry standard model. This standardized interface has a universal interchangeability definition and is not constrained by any manufacturer's proprietary protocol. When the tethering mechanism 300, optical cable, or UAV interface is damaged, standardized spare parts can be directly purchased for replacement, eliminating the need for system re-customization or recalibration. This reduces the system's lifecycle maintenance costs, improves the convenience of spare parts supply, and allows the UAV 400 to be compatible with different models of ground power stations 100, enhancing the equipment's versatility and interoperability. The physical fixed connection provides a defined mechanical positioning. The robust metal shell and locking mechanism resist continuous vibrations and instantaneous impacts generated during flight, preventing loosening or fretting wear at the connection points. Throughout the UAV 400's entire flight envelope, the optical path connection remains stable, avoiding optical power fluctuations or disconnections caused by loose connections. This ensures the stability of the input energy to the photoelectric conversion unit 410 and guarantees the safe operation of the UAV's power system.

[0054] like Figure 1 and Figure 3As shown, in this embodiment, the tethering mechanism 300 includes a connector 310 disposed at the output port 202 of the lightweight flexible high-energy laser transmission optical cable 200, and a docking seat 320 disposed on the tethering interface 401 of the UAV 400; the connector 310 and the docking seat 320 achieve rapid connection and disconnection through one or more of the following methods: magnetic adsorption, mechanical snap-fit ​​or electromagnetic lock, and ensure stable alignment of the optical fiber path of the lightweight flexible high-energy laser transmission optical cable 200 and the optical input port 201 of the photoelectric conversion unit 410 in the connected state. Connector 310 and docking seat 320 are connected by one or more of the following methods: magnetic adsorption, mechanical snap-fit, or electromagnetic lock. Magnetic adsorption provides initial pre-positioning and holding force, reducing the precision requirements of docking operations. Mechanical snap-fit ​​provides definite mechanical stop and shear resistance, ensuring that the connection does not loosen under high dynamic flight loads. Electromagnetic lock can be actively locked or unlocked through electronic control signals and is linked with the flight control system of UAV 400. The tethering mechanism 300 has both the convenience of manual docking and the structural strength to resist flight aerodynamic loads and cable tension. At the same time, it supports automatic cable release in emergency situations (such as UAV 400 loss of control or power failure), taking into account both the stability of the connection and the safety of separation. The tethering mechanism 300 ensures stable alignment between the optical fiber path and the optical input port of the photoelectric conversion unit in the connected state. The mating surfaces of the connector 310 and the docking seat 320 (such as positioning pins, positioning grooves, tapered surfaces, etc.) are precision machined. Utilizing the geometric tolerance constraints of the structure itself, the coaxial alignment of the optical axis is automatically completed at the same time as the physical connection is completed. There is no need for a complex active servo alignment system. Low-loss coupling between optical fibers or between optical fibers and optical windows can be achieved solely by the passive alignment of the mechanical structure. This simplifies the design of the optomechanical system at the UAV end, reduces system cost and weight, and eliminates the risk of optical path misalignment caused by vibration. The tethering mechanism 300 separates the connection function into two physically separate components: a connector and a docking station. This modular design allows the tethering mechanism 300 to be manufactured, tested, and replaced as an independent subsystem. When the connector 310 or docking station 320 is worn or damaged, it is not necessary to replace the entire optical cable or the entire UAV interface board. Only the corresponding module component needs to be replaced to restore the function, which significantly reduces maintenance difficulty and total life cycle cost. The standardized interface of the tethering mechanism 300 allows the same UAV 400 to be adapted to power stations 100 with different power levels, improving the platform's versatility.The tethering mechanism 300 supports rapid connection and disconnection, decoupling energy supply from physical restraint, allowing the UAV 400 to retain the ability to detach from the cable even in tethered mode. When the UAV 400 detects its own malfunction, encounters an irresistible external force (such as bird strikes or extreme wind shear), or needs to perform a temporary task beyond the tethering radius, it can immediately trigger the detachment mechanism, cut off the physical connection, and switch to the onboard battery-powered mode for emergency return or free flight, greatly improving the system's survivability and mission flexibility in complex operating environments.

[0055] like Figure 1 and Figure 3As shown, in this embodiment, in order to achieve reliable and rapid connection and optical path docking between the UAV 400 and the lightweight flexible high-energy laser transmission optical cable 200, a dedicated tethering mechanism 300 is designed. The tethering mechanism 300 includes: a connector 310, which is fixed to the output port 202 of the lightweight flexible high-energy laser transmission optical cable 200 and contains a precision mating port for protecting the fiber end face and realizing optical path docking; and a docking seat 320, which is fixed to the tethering interface 401 of the UAV 400 and contains an optical interface that matches the connector 310, which can directly guide the high-energy laser beam output from the optical fiber into the photoelectric conversion unit 410 inside the UAV 400. Connector 310 contains a precision mating port to protect the fiber end face, which is extremely fragile and sensitive to contamination as the physical interface for optical energy input. The precision mating port is usually made of hard alloy or ceramic material and is designed with a dust cap or sealing structure. In storage, transportation and non-connection states, it effectively prevents the fiber end face from being mechanically scratched, dusted or corroded by moisture, and avoids increased Fresnel reflection, light scattering loss or local overheating and burning caused by end face defects, thereby maintaining high efficiency and stability of optical path transmission in the long term. The docking seat 320 contains an optical interface that matches the connector 310, allowing high-energy laser beams to be directly introduced into the photoelectric conversion unit 410. The optical interfaces (such as ceramic ferrules, lens groups, or reflecting prisms) of the connector 310 and the docking seat 320 are precisely optically designed to automatically compensate for lateral, longitudinal, and angular deviations between the optical fiber and the input end of the photoelectric conversion unit 410 at the moment the physical connection is completed. This achieves efficient optical coupling from the transmission optical fiber to the photoelectric conversion unit 410 (such as a photovoltaic array or laser receiver head), reduces light energy dissipation and reflection loss, ensures that the optical power density input to the photoelectric conversion unit 410 meets the design expectations, and directly improves the overall efficiency of the energy supply system. As a dedicated component independent of the optical cable and UAV 400, the tethering mechanism 300 clarifies the responsibility interface for the connection, encapsulating the complex "optical-mechanical-electrical" alignment problem into a standardized mechanical action. Operators do not need to have professional fiber optic splicing or alignment skills; they only need to perform simple plugging and unplugging actions to complete the system deployment, reducing the risk of human error. The structural rigidity of the dedicated mechanism ensures that the connection parts will not move slightly or loosen under harsh conditions such as high-altitude strong winds and fuselage vibration, guaranteeing the physical continuity of the power supply link.The docking station 320 can directly guide the laser beam into the photoelectric conversion unit 410 inside the UAV 400, eliminating intermediate transfer links (such as free space transmission or additional light guide arms). The distance of light energy from the output end of the optical cable to the input end of the photoelectric conversion is the shortest and the optical path is the most stable. It reduces the light energy loss caused by multiple refractions and reflections, and at the same time makes the shape of the light spot and the light intensity distribution received by the photoelectric conversion unit 410 more uniform and stable. This is beneficial to the control of the back-end maximum power point tracking (MPPT) circuit and improves the stability of power output and dynamic response speed.

[0056] like Figure 1 and Figure 3As shown, in this embodiment, the connection between connector 310 and docking seat 320 can be achieved by using the magnetic adsorption of permanent magnets and ferromagnetic materials to achieve rapid initial alignment and fixation, supplemented by mechanical buckles for secondary locking, ensuring a stable connection during high-maneuverability flight. The optical channels inside connector 310 and docking seat 320 adopt a self-aligning design to ensure automatic alignment of the optical path during connection. The magnetic force generated by the permanent magnet has a non-contact attractive force within a certain spatial range. When connector 310 approaches docking seat 320, the magnetic force automatically guides the two to move along the magnetic field lines until the areas with opposite polarities are tightly fitted. Operators can complete the initial connection without precise visual alignment, achieving blind insertion functionality. This significantly shortens the tethered deployment time of UAV 400 in the field or in emergency situations, reduces the skill threshold and labor intensity for operators, and improves the system's rapid response capability. The connection structure is supplemented by mechanical latches for secondary locking; although magnetic adsorption provides rapid initial positioning, it may slip under high dynamic loads due to magnetic saturation or impact; mechanical latches (such as spring pins, claws, or rotary hooks) provide rigid mechanical interference and can withstand axial tensile and tangential shear forces far greater than magnetic forces; under high-maneuver flight (such as sharp turns, dives and pull-ups) or strong airflow disturbances, the tethering mechanism 300 can maintain absolute mechanical stability, prevent accidental disconnection of the connection and resulting power loss, and ensure the structural integrity and mission continuity of the power supply link under extreme conditions. The optical channels inside the connector 310 and the mating seat 320 adopt a self-aligning design, using precision-machined geometric features (such as tapered guide holes, spherical lens seats, or V-grooves) as physical positioning references. When the connector 310 and the mating seat 320 are mechanically mated, the optical elements (fiber ferrules or lenses) naturally fall into the predetermined coaxial position. High-precision automatic alignment of the fiber optic path and the input end of the photoelectric conversion unit 410 can be achieved without complex active adjustment mechanisms (such as piezoelectric ceramic fine-tuning platforms), eliminating optical axis offset caused by assembly errors or mechanical vibrations, and ensuring long-term stability and low-loss characteristics of optical energy transmission. The combination of magnetic adsorption and mechanical snap-fit ​​creates redundant physical connections. Even if one of the connection methods (such as magnetic force) demagnetizes due to high temperature or obstruction by foreign objects, the mechanical snap-fit ​​can still provide basic holding force. Conversely, this improves the fault tolerance of the tethering mechanism 300 in harsh environments (such as sandstorms, salt spray, and low temperatures) and reduces the risk of system failure due to a single point of failure. The self-alignment design significantly increases the repeated mating and unmating life of the connector 310, reduces the decrease in alignment accuracy caused by frequent replacements, and lowers the total life cycle maintenance cost of the system.

[0057] like Figure 1As shown, in this embodiment, the photoelectric conversion unit 410 includes: an optical coupling interface 411 for receiving a high-energy laser beam from the output port 202 of the lightweight flexible high-energy laser transmission optical cable 200; a high-efficiency photoelectric converter 412, which is a multi-junction photovoltaic cell or a vertical cavity surface-emitting laser array optimized for laser wavelength, for converting light energy into electrical energy and achieving a photoelectric conversion efficiency of at least 50%; and a heat dissipation component 413, which is thermally connected to the high-efficiency photoelectric converter 412 for dissipating the heat generated during the conversion process. The high-efficiency photoelectric converter 412 is a multi-junction photovoltaic cell or vertical-cavity surface-emitting laser array optimized for laser wavelengths, with a photoelectric conversion efficiency of at least 50%. Unlike ordinary solar cells with a wide spectral response, the photoelectric converter optimized for specific laser wavelengths (such as 808nm, 940nm, 1064nm, etc.) has a semiconductor material bandgap that is precisely matched with the incident photon energy. It also uses a multi-junction structure to absorb energy of different wavelengths in a stepped manner, suppressing thermal relaxation loss and transmission loss. This breaks through the theoretical limitation of the Shockley-Quisser limit of traditional silicon-based photovoltaic devices under monochromatic light, achieving a photoelectric conversion efficiency of over 50%. This means that with the same input optical power, more electrical energy can be output, directly improving the available power margin of the UAV power system, or reducing the demand for 100 laser power at the power station at the same output power, thereby reducing the load on ground equipment. The optical coupling interface 411 is used to receive a high-energy laser beam from the optical cable. It includes a collimating lens, a focusing lens, or an optical waveguide structure. It can shape, reduce, or homogenize the divergent beam or distorted spot output from the optical cable and project it onto the photosensitive surface of the high-efficiency photoelectric converter 412 with the optimal numerical aperture and spot size. This improves the light energy collection rate and avoids energy waste caused by the spot overflowing the photosensitive area. At the same time, the uniform irradiance distribution helps to prevent local overheating of the photoelectric converter, ensuring the stability of the conversion efficiency and the long-term reliability of the device. The heat dissipation component 413 is thermally connected to the high-efficiency photoelectric converter 412 to dissipate the heat generated during the conversion process. Even at a conversion efficiency of up to 50%, about 50% of the input energy is still converted into heat energy. The heat dissipation component 413 (such as at least one of heat pipe, heat spreader, microchannel cold plate or finned heat sink) is in close contact with the back of the photoelectric converter through a high thermal conductivity interface material (such as graphene film, thermal grease or phase change material). It uses heat conduction and convection to quickly dissipate heat to the surrounding environment, effectively controlling the operating junction temperature of the photoelectric converter, preventing semiconductor bandgap drift, increased series resistance and roll-off of conversion efficiency caused by excessive temperature, avoiding permanent damage caused by thermal failure, and significantly extending the service life of the core photoelectric conversion device.The photoelectric conversion unit 410 integrates optical, electrical, and thermal functions into one unit. Through miniaturized packaging and lightweight design, it minimizes the size and weight of the unit while ensuring high conversion efficiency and heat dissipation capacity. This reduces the power-to-weight ratio of the airborne energy system, enabling the UAV 400 to carry a larger power payload or extend its loiter time within a limited lift budget. This enhances the overall competitiveness of the tethered UAV platform in specific application scenarios (such as long-term fixed-point monitoring and emergency communication relay).

[0058] like Figure 1As shown, in this embodiment, the optical coupling interface 411 includes a homogenizing element. A high-energy laser beam from the optical fiber enters the optical coupling interface 411 through the docking seat 320 and then uniformly illuminates the high-efficiency photoelectric converter 412. The homogenizing element (such as a diffractive optical element, microlens array, or integrating bar) redistributes the energy of the laser beam entering the optical coupling interface 411. The laser spot output from the optical fiber usually exhibits a Gaussian distribution or has hot spots caused by mode coupling, i.e., the energy is extremely high at the center and low at the edge. If such a non-uniform spot is directly projected onto the surface of a multi-junction photovoltaic cell, the local optical power density will far exceed the optimal operating range of the device, causing severe carrier saturation and recombination losses, thereby reducing the overall photoelectric conversion efficiency. The homogenizing element eliminates the energy peaks within the spot, making the irradiance on the entire photosensitive surface more uniform, ensuring that the photoelectric conversion unit 410 operates within the optimal linear response region, thereby approaching or even exceeding the highest conversion efficiency threshold in the design specifications. The uniform illumination element achieves a spatially uniform distribution of heat energy. Non-uniform illumination can lead to localized hot spots on the surface of the photoelectric converter. These areas not only have low conversion efficiency but also generate the most concentrated Joule heat, easily forming hot spot effects, accelerating the aging of semiconductor materials, and even causing burnout. Uniform illumination allows the heat dissipation component 413 to face a uniformly distributed heat source, avoiding the surge in thermal resistance caused by excessively high local heat flux density. This allows the heat dissipation component 413 to dissipate heat more efficiently, preventing the roll-off of photoelectric conversion efficiency and irreversible device damage caused by local overheating, and significantly improving the long-term operational stability and safety of the system. The uniform illumination element improves the spatial utilization of light energy. The effective photosensitive area of ​​the high-efficiency photoelectric converter 412 usually has a specific geometric shape (such as a circle or rectangle), and the quantum efficiency of the edge region is often lower than that of the central region. The uniform illumination element can guide the excess energy originally concentrated in the central region to the underutilized edge region, filling the gap in edge light intensity, achieving full filling and utilization of the effective area of ​​the photoelectric converter, reducing light energy overflow loss caused by mismatched spot shape or uneven energy distribution, and maximizing the capture rate of input laser energy. The light-diffusing element improves the system's tolerance to optical path alignment errors. The light spot after light-diffusing is no longer sensitive to minor deviations in incident angle and position. During actual flight of the UAV 400, slight relative displacement may occur between the optical coupling interface 411 and the docking seat 320 due to fuselage vibration or cable sway. Even with slight defocusing or translation of the optical path, the light spot after light-diffusing can still maintain a relatively stable irradiance distribution projected onto the photoelectric converter, avoiding drastic fluctuations in optical power caused by alignment drift and ensuring the stability and anti-interference capability of the UAV 400's power input. The high-efficiency photoelectric converter 412 is preferably a multi-junction gallium arsenide photovoltaic cell optimized for laser wavelength, with a photoelectric conversion efficiency exceeding 50%. The heat dissipation component 413 uses heat pipes or a vapor chamber, combined with heat dissipation from the UAV 400's outer shell.

[0059] like Figure 1As shown, in this embodiment, the photoelectric conversion unit 410 further includes a power management module 420, which is electrically connected to the high-efficiency photoelectric converter 412. The power management module 420 includes a maximum power point tracking circuit and a DC-DC conversion circuit, which are used to optimize the power output and distribute the optimized power to the flight control system, power system and mission payload of the UAV 400. The power management module 420 includes a maximum power point tracking circuit and is electrically connected to the high-efficiency photoelectric converter 412. The output current-voltage characteristic curve of the photoelectric conversion unit 410 (especially the photovoltaic cell) is non-linear and has a unique maximum power point. The position of this point drifts in real time with changes in incident light intensity, ambient temperature, and device aging. The maximum power point tracking circuit samples the output voltage and current in real time and dynamically adjusts the equivalent input impedance, forcing the photoelectric converter to always operate at the voltage-current operating point with the highest output power. Even when the incident laser power fluctuates due to cloud cover or changes in flight attitude, it can prevent the photoelectric converter from falling into the low-efficiency region due to deviation of the operating point, ensuring that the conversion from light energy to electrical energy is always in the optimal energy extraction state, maximizing the potential value of the input light energy. The power management module 420 includes a DC-DC conversion circuit for distributing optimized power to various systems of the UAV 400. The DC voltage output by the high-efficiency photoelectric converter 412 typically varies drastically with light intensity, and its voltage level may not match the rated voltage required by the UAV 400's flight control system, power motor, or mission load. The DC-DC conversion circuit (such as a buck, boost, or buck-boost topology) can clamp or transform the unstable input voltage at the front end into the precise and stable voltage required by the subsequent system, achieving decoupling between the energy supply end and the load end. This allows each power-consuming unit inside the UAV 400 to be connected to a standard DC bus without requiring special design for the output characteristics of the photoelectric converter. This simplifies the electrical architecture design of the UAV 400 and improves compatibility and power supply security for different types of loads. The power management module 420 distributes optimized power to the flight control system, power system, and mission load. As the energy dispatching hub, the power management module 420 has built-in priority arbitration logic and power budget algorithm. When the total input power is limited (such as the output fluctuation of power station 100), the module can prioritize the power supply safety of the flight control system and power system. When necessary, it can temporarily cut off or reduce the power of non-critical mission loads (such as non-core sensors and lighting) to prevent the system from voltage collapse or shutdown due to overload, thereby improving the survivability of UAV 400 under complex working conditions and the continuity of mission execution.The power management module 420 filters and regulates the raw output power. The DC power generated during photoelectric conversion may contain high-frequency ripple and noise, which could lead to logic errors or hardware damage if directly driving precision electronic equipment. The output power features low ripple and high stability, effectively filtering out electromagnetic interference and protecting the expensive flight control computer and highly sensitive payloads from power supply noise, thus extending the fault-free operating time of the onboard electronic equipment. The optimized power is distributed to the UAV 400's flight control system, power system, and payload on demand. The power management module 420 monitors and coordinates the power requirements of the UAV 400 and its payloads, checking battery charge levels and power consumption. The payloads include lighting sources and communication bays. The power management module 420 manages the power output from the photovoltaic cells and adjusts it to the different voltages required by various systems of the UAV 400 (such as flight control, ESCs, and payloads) via a DC-DC converter. Because the energy source is continuous and stable, the power management module 420 optimizes the efficiency of the entire power system.

[0060] like Figure 1 and Figure 4As shown, this embodiment also includes an optical fiber winding and unwinding management device 500. The optical fiber winding and unwinding management device 500 is located at the power supply station 100, on an independent tethering tower, or mounted on a drone 400. It is used to automatically wind up and unwind and control the tension of the lightweight flexible high-energy laser transmission optical cable 200 during the take-off, landing, or flight of the drone 400. The fiber optic cable winding and unwinding management device 500 is used to control the tension of the optical cable during the take-off, landing, or flight of the UAV 400. The weight and aerodynamic drag of the lightweight, flexible optical cable in the air can cause it to sag or swing violently. If the tension is too low, the optical cable may be damaged by friction with the ground or obstacles; if the tension is too high, it will significantly increase the lifting load of the UAV 400. By outputting a constant anti-dragging torque through real-time feedback control (such as a torque motor or magnetic powder brake), the optical cable is kept within the set tension range. The optical cable always maintains a relatively stable catenary shape in the air, reducing the aerodynamic drag and induced torque caused by random swinging, and reducing the control surface deflection and power output required by the UAV 400 to maintain attitude stability, thereby indirectly saving energy and improving flight stability. The fiber optic cable reel-and-deel management device 500 can automatically reel in and deelerate the optical cable as the UAV 400 ascends, descends, or flies, synchronizing the stored length of the optical cable with the spatial position of the UAV 400 in real time. When the UAV 400 climbs or moves away from the power station 100, the device actively releases the cable; when the UAV 400 descends or returns to base, the device actively reels in the cable. This eliminates the physical constraints of fixed cable length in traditional tethered systems that limit flight altitude, allowing the UAV 400 to freely plan its flight path within a set operating radius. This achieves semi-maneuverable flight capability in tethered mode, expanding the coverage and mission flexibility of single-point tethering. The fiber optic cable reel management device 500 can be installed at the location of the power supply station 100, on an independent tethered tower, or mounted on a drone 400. Different deployment locations correspond to different mechanical transmission paths and operational requirements. Ground deployment is suitable for fixed base stations, using the earth as an anchor point to provide maximum stability. Tethered tower deployment can increase the height of the optical cable above the ground and reduce interference from ground obstacles. Airborne mounting completely eliminates the limitations of ground retrieval mechanisms, enabling the drone 400 to have all-terrain following operation capabilities. The system can flexibly select the optimal deployment scheme according to the actual operating environment (such as urban buildings, mountainous jungles, and moving vehicles), improving the adaptability and survivability of the entire power supply system in complex geographical environments. The 500-pair fiber optic cable winding and management device automatically winds up and unwinds optical cables in an orderly manner. Through a cable routing mechanism (such as a lead screw or optical rod cable routing device), it controls the number of layers and the neatness of the cable winding on the drum, preventing disordered layers, wire compression, or dead folds in the cable during winding and unwinding. It avoids fiber breakage or coating damage caused by excessive bending, twisting, or mutual compression of the optical cable, protects the fragile internal waveguide structure and the high-strength external protective layer of the optical cable, significantly extends the service life of high-value special optical cables, and reduces the total life cycle maintenance cost of the system.

[0061] like Figure 1 and Figure 4As shown, in this embodiment, the fiber optic winding and unwinding management device 500 includes a reel 510, a drive mechanism 520, a tension sensor 530, and a controller 540. The tension sensor 530 monitors the tension of the lightweight, flexible, high-energy laser transmission optical cable 200 in real time. The controller 540 controls the drive motor to adjust the winding and unwinding speed of the optical cable based on the tension data and the distance and speed information of the UAV 400, so as to maintain a preset tension range. Tension sensor 530 monitors the fiber optic cable tension in real time. Controller 540, based on this data and the distance and speed information of UAV 400, controls the drive motor to adjust the take-up and take-down speed to maintain the preset tension range, forming a typical closed-loop control system. Tension sensor 530 acts as a feedback element, acquiring the controlled quantity (tension) in real time. Controller 540 (such as a PLC or embedded microprocessor) compares the feedback quantity with the set value and calculates the deviation. Drive mechanism 520 (such as a torque motor or servo motor) adjusts the output speed and torque according to control commands. Regardless of whether UAV 400 is accelerating, decelerating, or hovering, the system can automatically offset tension fluctuations caused by changes in inertial force, gravity, and air resistance, keeping the fiber optic cable tension within a safe threshold. This prevents the fiber optic cable from breaking due to excessive tension or being pulled to ground equipment by UAV 400, and also prevents the fiber optic cable from touching the ground and wearing down or getting tangled in the propeller due to insufficient tension, fundamentally ensuring the physical safety of the human-machine system. The controller 540 not only uses tension data but also combines the distance and speed information of the drone 400 for coordinated control. Simple tension feedback control may have lag or cause system oscillation. By introducing the real-time position (distance) and motion state (speed) of the drone 400 as feedforward compensation signals, predictive control can be achieved. The system can predict the motion trend of the drone 400 (such as predicting the upcoming rapid departure action) and adjust the deployment and retraction speed in advance to achieve real-time matching between the fiber optic cable length and the position of the drone 400. This eliminates the maneuver lag phenomenon, allowing the drone 400 to maintain a smooth handling feel and agile dynamic response even when tethered, as if it has been freed from the constraints of the cable. The system maintains a preset tension range. Fiber optic transmission loss is extremely sensitive to micro-bending. Excessive tension will cause the fiber to be in a stretched state, changing its waveguide structure; insufficient tension may cause the optical cable to sag on the reel 510, resulting in a bend. Constant tension ensures that the optical fiber is always in the optimal strain state when transmitting energy, avoiding additional transmission loss or polarization mode dispersion caused by mechanical deformation. It also prevents fatigue damage to the high-strength fibers inside the optical cable due to repeated alternating stress, thus simultaneously ensuring the physical stability of the optical path transmission and the structural lifespan of the optical cable.The fiber optic cable winding and unwinding management device 500 includes an automated drive and winding mechanism, which entrusts the tedious and high-risk manual cable winding and unwinding operations to precision machinery. This shortens the deployment and retrieval time of the tethered UAV system, reduces the workload and skill threshold of operators, reduces the probability of accidents caused by improper human operation (such as tripping due to mismatched winding and unwinding speeds), and improves the system's rapid response capability in scenarios with extremely high timeliness requirements such as emergency rescue and temporary monitoring.

[0062] like Figure 1 and Figure 4As shown, in this embodiment, relying on the tension sensor 530 (stress sensor) in the fiber optic winding and unwinding management device 500 and setting a preset threshold range, when the tension (stress) on the lightweight flexible high-energy laser transmission optical cable 200 is greater than the preset threshold range, the drive motor drives the reel 510 to perform the unwinding operation; when the tension (stress) on the lightweight flexible high-energy laser transmission optical cable 200 is less than the preset threshold range, the drive motor drives the reel 510 to perform the winding operation. Tension sensor 530 monitors the tension of lightweight, flexible, high-energy laser transmission optical cable 200. When the tension exceeds a preset threshold range, it drives reel 510 to release the cable; when the tension falls below the preset threshold range, it drives reel 510 to retract the cable. By setting an upper and lower threshold for tension, a hysteresis comparison control logic is formed. When the UAV 400 moves away or climbs, causing the cable tension to increase and exceed the upper threshold, the system automatically releases the cable to reduce the cable length and tension. When the UAV 400 approaches or descends, causing the tension to decrease and fall below the lower threshold, the system automatically retracts the cable to maintain cable tension. The cable tension is always limited within a preset safety window, avoiding the risk of cable breakage or slack ground contact due to excessive tension. This ensures that the cable drag force experienced by the UAV 400 during three-dimensional maneuvering remains relatively stable, eliminating unexpected pitch or yaw moment interference and significantly improving flight attitude stability and control accuracy. The cable deployment and retraction operations directly alter the geometry of the optical cable in the air. The sag of the optical cable is inversely proportional to the tension. By controlling the tension within a preset range, the sag of the optical cable is effectively controlled, preventing it from rubbing against, wearing down, or tangling with ground vegetation, buildings, or other obstacles due to excessive cable length or sag. It also reduces aerodynamic drag and induced vibration caused by the large swing of the optical cable in the wind, lowering the additional power output required by the UAV 400 to overcome cable resistance, and indirectly extending the effective operating time. The preset threshold range defines the safe operating area of ​​the optical cable. Although the lightweight, flexible, high-energy laser transmission optical cable 200 contains a high-strength protective layer, it still has a maximum tensile strength limit. Once the optical cable encounters a sudden external force (such as a strong wind, bird strike, or snag on a foreign object on the ground) that causes a sudden surge in tension, the system can quickly respond by releasing the cable to relieve the tension and prevent the optical cable from breaking due to exceeding the yield strength. Conversely, when the optical cable is too slack and may get caught in the landing gear or propeller, the system will promptly retract the cable to tighten it and prevent mechanical interference accidents. This limit protection mechanism greatly improves the system's fault tolerance and survivability in complex environments, protecting high-value special optical cables and UAVs 400.The control strategy relies solely on a single physical quantity input from the tension sensor 530. Its logic is clear and its execution decisive. Compared to complex algorithms that require fusing information from multiple sources such as distance, velocity, and acceleration, threshold-based trigger control has extremely low computational resource requirements and the shortest response path. The system can react to sudden tension changes with millisecond-level response speeds, reducing the computational latency and software failure probability of the control system, and improving the reliability and robustness of the electromechanical system in harsh electromagnetic or high / low temperature environments. The drive mechanism 520 uses a servo motor. When the UAV 400 takes off, the drive mechanism 520 actively releases the cable; during hovering or maneuvering, the controller 540 dynamically adjusts the release and take-up speed based on feedback from the tension sensor 530 and position and / or velocity information from the UAV 400, maintaining appropriate suspension tension on the optical fiber and avoiding excessive pulling or dragging. The design of the reel 510 ensures that the optical fiber is wound with an arc greater than its minimum bending radius to prevent damage.

[0063] like Figure 1As shown, in this embodiment, the power supply station 100 includes a high-power continuous laser 110, a laser power control and safety module 120, and an initial coupling optical system 130. The high-power continuous laser 110 is a fiber laser, semiconductor laser, solid-state laser, etc. The laser power control and safety module 120 is configured to immediately send an emergency stop signal or a power reduction signal to the power supply station 100 to cut off or reduce the laser output when it detects that the lightweight flexible high-energy laser transmission optical cable 200 is broken, disconnected, or has an abnormal signal. The initial coupling optical system 130 efficiently couples the laser output from the high-power continuous laser 110 into the high-energy laser and transmits it to the input port 201 of the lightweight flexible high-energy laser transmission optical cable 200. The high-power continuous laser 110 employs fiber lasers, semiconductor lasers, or solid-state lasers, among others. Different types of lasers possess different spectral characteristics, electro-optical efficiencies, and beam qualities. Fiber lasers offer excellent beam quality and heat dissipation, making them suitable for long-distance, low-loss transmission. Semiconductor lasers boast extremely high electro-optical conversion efficiency and miniaturization potential, making them suitable for portable or vehicle-mounted deployments. Solid-state lasers can provide high peak power and specific wavelength output. The power supply station 100 can flexibly select the optimal laser source solution based on actual application requirements (such as transmission distance, environmental conditions, and power level), achieving a balance between power density, volume, weight, and cost in the energy supply system, thereby enhancing the system's adaptability and technological advancement. The laser power control and safety module 120 is configured to immediately send an emergency stop signal or a power reduction signal to cut off or reduce laser output when an optical cable break, connection disconnection, or signal abnormality is detected. When the tethered optical cable physically breaks or the connector 310 falls off, the high-energy laser beam will lose the constraint of the transmission medium and radiate directly into the atmosphere, posing a significant safety hazard to personnel, aircraft, and the surrounding environment. By real-time monitoring of the optical cable's return light signal, temperature sensor feedback, or the UAV 400 communication link status, a hardware-level safety interlocking loop independent of the main control system is constructed. Within milliseconds of an emergency, the laser output is forcibly cut off or reduced to below a safe power level, completely eliminating the risk of burns, blindness, or fire caused by high-energy laser leakage and ensuring the inherent safety of the system throughout its entire life cycle.The initial coupling optical system 130 efficiently couples the laser into the input port 201 of the high-energy laser transmission optical cable. The beam diameter, numerical aperture, and spot shape of the laser output are usually not perfectly matched with the mode field diameter, acceptance angle, and fiber core geometry of the transmission optical cable. The initial coupling optical system 130 (including collimating mirror, focusing mirror, beam shaper, and mode adapter) expands, shrinks, or homogenizes the beam so that it enters the fiber core with the optimal spot size and incident angle. This improves the coupling efficiency of laser energy to the fiber core, reduces end-face reflection loss and cladding leakage caused by Fresnel reflection, mode field mismatch, or excessive incident angle, and avoids local overheating caused by energy concentration in a small area of ​​the fiber end face, preventing melting damage to the fiber end face and ensuring the stability and continuity of high-power laser transmission. The laser power control and safety module 120 dynamically manages the output power. Changes in the drone 400's flight attitude, payload activation / deactivation, and ambient wind speed all cause real-time fluctuations in its power demand. By receiving power request signals from the drone or monitoring the output voltage of the photoelectric conversion unit 410, the module adjusts the laser's drive current accordingly. This achieves precise matching between the power supply station 100's output power and the drone 400's real-time power consumption, preventing energy waste and heat buildup due to excess power, and preventing power outages or forced landings due to insufficient power. This optimizes the overall energy efficiency of the entire power supply chain. The laser power control and safety module 120's safety mechanisms include, but are not limited to: cutting off the laser in case of fiber optic cable breakage; reducing power in case of excessive fiber optic cable tension; reducing power in case of photoelectric converter overheating; reducing power in case the drone 400's battery is nearly fully charged; and increasing laser output power in case of increased power consumption. The logic is to ensure the system's safe and stable operation. The laser power control and safety module 120 is responsible for the startup and power regulation of the high-power continuous laser 110, and integrates multiple safety protections such as emergency stop, high and low temperature alarms, and connection loosening alarms. It issues alarms when encountering over-temperature or over-limit conditions, and provides emergency stop for laser output in case of emergencies. For example, when a fiber optic breakage detection sensor (such as a photodetector monitoring backlight) or a communication link detects a connection abnormality, the laser power control and safety module 120 can quickly send an emergency stop signal to the system, cutting off laser output within milliseconds to ensure system safety. Specifically, the laser power control and safety module 120 can quickly send an emergency stop signal to the system, cutting off laser output within milliseconds. Specifically, it uses a photodetector to detect backlight; when the backlight suddenly increases, indicating a change in the transmission link, the control circuit immediately outputs an emergency stop signal to the high-power continuous laser 110, causing the high-power continuous laser 110 to stop emitting light. The initial coupling optical system 130 includes a precision adjustment frame and a focusing lens.The high-power continuous laser 110 employs a semiconductor laser with an output power of several hundred watts to several kilowatts and an output wavelength of 808 nm, or the high-power continuous laser 110 employs a fiber laser with an output power of several hundred watts to several kilowatts and a wavelength of 1080 nm, which matches the response band of commonly used high-efficiency photovoltaic cells.

[0064] like Figure 5As shown, the UAV power supply method based on optical fiber and cable in this embodiment adopts the above-mentioned UAV power supply system based on optical fiber and cable, including the following steps: S1, the output port 202 of the lightweight flexible high-energy laser transmission optical cable 200 is fixedly connected to the tethering interface 401 of the UAV 400 through the tethering mechanism 300, establishing an optical link from the power supply station 100 to the UAV 400; S2, the high-power continuous laser 110 of the power supply station 100 is activated, and the high-energy laser beam is transmitted to the photoelectric conversion unit 410 of the UAV 400 through the lightweight flexible high-energy laser transmission optical cable 200; S3, the photoelectric conversion unit... 410 converts the received laser energy into DC power in real time, and after processing by the power management module 420, directly drives the motors and flight control system of the UAV 400; S4, during the flight operation of the UAV 400, the fiber optic winding and unwinding management device 500 synchronously winds up and unwinds the lightweight flexible high-energy laser transmission cable 200 according to the flight status of the UAV 400, keeping it in a proper suspension state; S5, when the UAV 400 needs to be recovered or the mission ends, it is controlled to fly back to the vicinity of the power supply station 100, and the connection between the lightweight flexible high-energy laser transmission cable 200 and the UAV 400 is disconnected through the tethering mechanism 300. This invention relates to a method for powering unmanned aerial vehicles (UAVs) based on optical fiber cables. By sequentially executing steps such as establishing an optical link, initiating laser transmission, real-time power conversion, dynamic fiber optic cable deployment and retraction, and safe disconnection, the complex tethered power supply operation is decomposed into a series of logically rigorous and clearly defined procedures. This eliminates the arbitrariness and omission risks inherent in manual operation, ensuring that the system is in the same optimal initial state (e.g., moderate fiber optic cable tension and precise optical alignment) for each mission. This significantly reduces the probability of mission failure due to operational errors and improves the reliability and stability of the system in repetitive operations. In step S1, the output port 202 of the optical cable is fixedly connected to the tethering interface 401 of the UAV 400 through the tethering mechanism 300, establishing an optical link and completing the physical switch from ground stationary to aerial power supply. Due to the use of a rapid connection mechanism, this process is extremely short. The UAV 400 can obtain full-power ground energy support instantly upon takeoff without undergoing battery preheating or power ramp-up, achieving plug-and-play energy supply. This shortens the system deployment time in emergency response scenarios and meets the requirements for rapid response. Steps S2 to S3 realize the real-time conversion and processing of laser energy into DC power, constructing a continuous energy flow channel of "laser generation - fiber optic transmission - photoelectric conversion - power management", and the power management module 420 (including MPPT and DC-DC) intervenes in real time, eliminating the chemical energy storage lag in the traditional battery charging process and realizing zero-delay transmission of energy from the ground to the airborne. At the same time, the high-quality DC power with stable voltage and current directly drives the flight control and motors, ensuring the stability and response speed of the power output of the UAV 400 when the load changes suddenly (such as rapid acceleration and wind resistance), thus improving the flight quality.Step S4 involves the fiber optic cable being wound and unwound synchronously according to the flight status via the fiber optic cable rewind and management device 500 during flight. The physical length of the cable is managed as a real-time function of the UAV 400's flight trajectory. The UAV 400's maneuverability in three-dimensional space is no longer limited by a fixed-length cable, allowing it to freely ascend, descend, hover, and move within a preset radius. This achieves semi-maneuverable operation capability while tethered, effectively expanding the operational range covered by a single unit and overcoming the limitations of traditional tethered UAVs 400 that remain stationary. Step S5 controls the UAV 400 to fly back to the vicinity of the power station 100 before disconnecting. This physical separation operation is performed under close-range, low-speed, and low-risk conditions, avoiding secondary disasters such as cable entanglement in the propeller or injury to personnel on the ground that could occur during high-altitude, high-speed cable breakage. Simultaneously, the standardized retrieval process protects the expensive tether interface 401 and connector 310 from damage caused by rough handling, extending the lifespan of core components and reducing overall lifecycle maintenance costs. This invention presents a power supply method for UAVs 400 based on optical fiber and cable. By constructing a logically closed-loop and orderly standard operating procedure, it automates the entire lifecycle energy supply for UAVs 400 from deployment and operation to recovery. This not only solves the problems of complex operation, slow response, limited maneuverability, and high safety risks in traditional tethered operations, but also elevates the operational efficiency, safety, and environmental adaptability of tethered UAV systems to a new level through the synergistic effect of real-time optical path establishment, real-time energy transmission, and dynamic cable management. It provides a replicable and highly reliable engineering implementation plan for long-endurance UAV operations.

[0065] In this embodiment, the power supply method for the UAV 400 based on optical fiber and cable specifically includes: preparation and docking: the UAV 400 lands or hovers in the docking area near the power supply station 100; the operator or automated robotic arm connects and locks the connector 310 of the high-energy laser transmission optical cable output port 202 to the docking seat 320 on the UAV 400; startup and takeoff: the power supply station 100 is powered on, and the high-power continuous laser 110 starts at low power; the laser is transmitted to the UAV 400 through optical fiber and received by the photoelectric conversion unit 410; after the power management module 420 confirms that the power supply is stable, the UAV 400... The motor is started, and the drone takes off under the synchronous cable release control of the fiber optic winding and unwinding management device 500; continuous operation: the drone 400 flies to the target area to perform the mission; during this period, the power supply station 100 continuously provides laser energy, and the drone 400 achieves "unlimited endurance"; the fiber optic winding and unwinding management device 500 adjusts the fiber status in real time according to the movement of the drone 400; recovery and disconnection: after the mission ends, the drone 400 returns to the docking area and lands; the high-power continuous laser 110 reduces its power or turns off; the connection of the tethering mechanism 300 is disconnected, and the fiber optic winding and unwinding management device 500 retracts the high-energy laser transmission cable into the reel 510. During the startup phase, a high-power continuous laser 110 is used for low-power startup. The UAV 400 only starts its motors after the power management module 420 confirms that the power supply is stable, thus establishing a startup sequence of "optical path first, power later". The low-power laser is used to detect the optical path continuity and alignment status, avoiding fiber end face breakdown or photoelectric converter overload that may be caused by direct injection of high power. It effectively prevents energy accumulation and thermal damage caused by loose connector 310, fiber bending or contamination, ensuring the physical safety and electrical stability of the energy transmission link in the early stage of establishment and eliminating the surge impact risk in the cold start phase. During the takeoff of the UAV 400, the synchronous cable release control, in conjunction with the fiber optic winding and unwinding management device 500, ensures that the cable provides upward assistance immediately upon liftoff, rather than downward drag. This reduces the additional lift margin required for takeoff, allowing the UAV 400 to take off smoothly even with a full payload. It also reduces the risk of fuselage tilting or tipping due to cable dragging or sudden tautness, thus improving the safety and success rate of the takeoff process. During continuous operation, the power station 100 continuously provides laser energy, using the ground power grid or generator as an unlimited energy source, replacing the limited capacity of the onboard chemical batteries. This breaks through the endurance bottleneck of the UAV 400, which is limited by battery energy density, and achieves theoretical unlimited endurance. This enables the UAV 400 to perform long-term surveillance across day and night, long-term communication relay, or persistent fixed-point operation tasks without having to frequently return to replace batteries due to power depletion, thus improving the mission efficiency and time coverage of a single sortie.During the recovery phase, the UAV 400 is controlled to return to the docking area and land. The connection is disconnected after the high-power continuous laser 110's power is reduced or turned off. This confines the high-risk operation (physical connection and disconnection) to a low-altitude, low-speed, controllable near-field environment, and cuts off the energy source to eliminate radiation risks. This avoids secondary disasters such as cable entanglement in the propeller or injury to personnel on the ground that could occur if the cable breaks during high-altitude, high-speed flight. Simultaneously, power withdrawal ensures that operators are not exposed to high-energy laser radiation when contacting connector 310, achieving dual protection for operator safety and expensive onboard equipment. The method covers a complete closed loop from preparation for docking to fiber optic cable recovery, breaking down the complex tethering operation into multiple logically clear standard steps. Each step is predicated on the completion of the previous step, forming a standardized operating procedure (SOP). This lowers the technical threshold for operators and the probability of error, ensuring consistency and repeatability of each task execution, and improving the system's maintenance convenience and fault traceability during long-term operation. By implementing a phased, time-sequential, and safety-interlocked operational process, the safe establishment and stable operation of the high-power laser transmission link were ensured, realizing fully automated energy support for the UAV 400 from takeoff and operation to recovery. This not only solved the problems of complex operation, high risk, and limited endurance in traditional tethered operations, but also elevated the safety, reliability, and mission continuity of the tethered UAV system to a new level of engineering application through the timing control of energy injection and the dynamic management of cable status. This provides a practical and safe implementation plan for long-endurance UAV 400 operations.

[0066] In practice, a continuous power supply system and method for unmanned aerial vehicles (UAVs) based on optical fiber cables is provided, belonging to the field of UAV tethered power supply technology. This invention aims to solve the problems of low flight altitude, poor maneuverability, and limited operating radius caused by the bulky power cables of traditional tethered UAVs. The continuous power supply system for UAVs based on optical fiber cables includes: a ground power station for generating high-power continuous laser; a lightweight, flexible, high-energy laser transmission optical cable 200, one end of which is optically connected to the power station 100, and the other end is physically fixed to the UAV 400 via a tethering mechanism 300; and an onboard photoelectric conversion unit 410 and a power management module 420 integrated on the UAV 400. During the mission of the UAV 400, the lightweight, flexible, high-energy laser transmission optical cable 200 always serves as the physical connection line, transmitting laser energy from the power station 100 to the UAV 400 with extremely high efficiency (>95%). The onboard photoelectric conversion unit 410 converts the light energy into electrical energy in real time, directly driving the flight of the UAV 400. This invention replaces traditional power cables with extremely lightweight optical fibers, breaking through the fundamental limitations of tethered drones in terms of weight, altitude, maneuverability, and continuous operation time, and can achieve theoretically unlimited endurance.

[0067] The beneficial effects of this invention include: Extremely lightweight: The mass per unit length of the laser transmission fiber is much smaller than that of a copper cable with equivalent transmission capacity, which greatly reduces the load of the tethered system on the UAV 400 and significantly improves flight altitude and maneuverability.

[0068] Extremely high transmission efficiency: Laser transmission loss in optical fiber is extremely low (less than 1 dB / km), and the overall energy transmission efficiency is far higher than that of power cables and free space laser transmission.

[0069] High power capacity: Optical fiber can withstand extremely high peak and average power, meeting the power requirements of various large and medium-sized UAVs.

[0070] High reliability: Wired connection is unaffected by weather, eliminates the risk of misalignment, and provides a stable and reliable energy supply.

[0071] High safety: The laser energy is confined inside the optical fiber, eliminating the risk of radiation leakage and ensuring safety for the environment and personnel.

[0072] Functional integration: It is easy to integrate communication fiber 250 into optical fiber to achieve simultaneous transmission of energy and signal in one line.

[0073] Example 1: In a typical long-term area surveillance embodiment, the power supply station 100 is mounted on the roof of a command vehicle. The lightweight, flexible, high-energy laser transmission fiber optic cable 200 is 300 meters long, with a linear density of 20 grams per meter, and weighs only 6 kilograms, far lighter than a copper cable of equivalent power (which could weigh tens of kilograms). A quadcopter drone 400, equipped with a photoelectric conversion unit 410, can easily ascend to an altitude of 300 meters after being connected via a tethering mechanism 300, providing 24-hour uninterrupted surveillance of an area with a radius of approximately 300 meters. Video data can be transmitted in real-time via a communication fiber optic cable 250 integrated into the fiber optic cable. The drone 400 is highly maneuverable and not limited by battery power.

[0074] Matters not covered in this invention are common knowledge.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0076] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A power supply system for unmanned aerial vehicles (UAVs) based on optical fiber cables, characterized in that, include: The power station (100), deployed on the ground or mounted on the mothership, is used to generate and output high-energy laser beams as energy carriers; A lightweight, flexible high-energy laser transmission optical cable (200) is optically coupled to a power supply station (100) at its first end. It is used to guide a high-energy laser beam through a low-loss optical path for long-distance energy transmission and to avoid electromagnetic radiation interference to the transmission channel. The drone (400) is equipped with a photoelectric conversion unit (410), which is physically connected to the second end of a lightweight flexible high-energy laser transmission optical cable (200) to receive a high-energy laser beam transmitted through the lightweight flexible high-energy laser transmission optical cable (200) and convert it into electrical energy through the photoelectric conversion unit (410) to provide all or part of the power required for flight and mission payload. By using a laser-to-electrical energy conversion mode based on a lightweight, flexible, high-energy laser transmission cable (200), the hovering height and operating radius of the UAV (400) are decoupled, and the constraint of the onboard battery weight on flight performance is eliminated, ensuring that the UAV (400) can maintain stable hovering and long-term loitering in complex airflow environments.

2. The UAV power supply system based on optical fiber and cable according to claim 1, characterized in that, The lightweight flexible high-energy laser transmission optical cable (200) uses single-clad fiber, double-clad fiber, triple-clad fiber, hollow-core photonic crystal fiber or anti-resonant hollow-core fiber, and / or the lightweight flexible high-energy laser transmission optical cable (200) includes a fiber core (210) for guiding light, a cladding (220) wrapped around the fiber core (210), a coating layer (230) wrapped around the cladding layer (220), and a high-strength flexible protective layer (240) wrapped around the coating layer (230). The lightweight, flexible, high-energy laser transmission optical cable (200) has a unit length mass of less than 30 g / m and a minimum bending radius of less than 20 cm; Based on the payload capacity and operating radius requirements of the UAV (400), the length of the lightweight flexible high-energy laser transmission optical cable (200) is set to 10 meters to 1000 meters.

3. The UAV power supply system based on optical fiber and cable according to claim 2, characterized in that, The lightweight flexible high-energy laser transmission optical cable (200) also integrates one or more communication optical fibers (250) for transmitting communication signals within its coating layer (230) or high-strength flexible protective layer (240) to form a composite optical cable that transmits both energy and signals.

4. The UAV power supply system based on optical fiber and cable according to claim 1, characterized in that, The UAV (400) is provided with a tethering interface (401), which is physically fixedly connected to the output port (202) of a lightweight flexible high-energy laser transmission optical cable (200) via a tethering mechanism (300). The tethering interface (401) adopts at least one of QBH, FC or SMA.

5. The UAV power supply system based on optical fiber and cable according to claim 4, characterized in that, The tethering mechanism (300) includes a connector (310) disposed at the output port (202) of the lightweight flexible high-energy laser transmission optical cable (200), and a docking seat (320) disposed on the tethering interface (401) of the UAV (400). The connector (310) and the mating seat (320) are connected and disconnected quickly by one or more of magnetic adsorption, mechanical snap-fit ​​or electromagnetic lock, and ensure stable alignment of the optical fiber path of the lightweight flexible high-energy laser transmission cable (200) and the optical input port (201) of the photoelectric conversion unit (410) in the connected state.

6. The UAV power supply system based on optical fiber and cable according to claim 1, characterized in that, The photoelectric conversion unit (410) includes: An optical coupling interface (411) is used to receive a high-energy laser beam from the output port (202) of a lightweight, flexible, high-energy laser transmission cable (200); A high-efficiency photoelectric converter (412) is a multi-junction photovoltaic cell or vertical-cavity surface-emitting laser array optimized for laser wavelength, used to convert light energy into electrical energy and achieve a photoelectric conversion efficiency of at least 50%; A heat dissipation component (413) is thermally connected to a high-efficiency photoelectric converter (412) to dissipate the heat generated during the conversion process.

7. The UAV power supply system based on optical fiber and cable according to claim 6, characterized in that, The photoelectric conversion unit (410) also includes a power management module (420), which is electrically connected to the high-efficiency photoelectric converter (412); The power management module (420) includes a maximum power point tracking circuit and a DC-DC conversion circuit for optimizing power output and distributing the optimized power to the flight control system, power system and mission payload of the UAV (400).

8. The UAV power supply system based on optical fiber and cable according to any one of claims 1 to 7, characterized in that, It also includes an optical fiber winding and unwinding management device (500), which is located at the power supply station (100), on an independent tethering tower, or mounted on a drone (400) to automatically wind up and unwind and control the tension of the lightweight flexible high-energy laser transmission optical cable (200) during the take-off, landing or flight of the drone (400).

9. The UAV power supply system based on optical fiber and cable according to claim 8, characterized in that, The fiber optic winding and unwinding management device (500) includes a reel (510), a drive mechanism (520), a tension sensor (530), and a controller (540). The tension sensor (530) monitors the tension of the lightweight flexible high-energy laser transmission optical cable (200) in real time. The controller (540) controls the drive motor to adjust the cable winding and unwinding speed according to the tension data and the distance and speed information of the UAV (400) in order to maintain the preset tension range.

10. The UAV power supply system based on optical fiber and cable according to any one of claims 1 to 7, characterized in that, The power station (100) includes a high-power continuous laser (110), a laser power control and safety module (120), and an initial coupling optical system (130). High-power continuous lasers (110) can be made from fiber lasers, semiconductor lasers, solid-state lasers, etc. The laser power control and safety module (120) is configured to immediately send an emergency stop signal or a power reduction signal to the power supply station (100) to cut off or reduce the laser output when it detects that the lightweight flexible high-energy laser transmission optical cable (200) is broken, disconnected, or has an abnormal signal. The initial coupling optical system (130) efficiently couples the laser output from the high-power continuous laser (110) into the high-energy laser and transmits it to the input port (201) of the lightweight flexible high-energy laser transmission cable (200).

11. A method for powering unmanned aerial vehicles (UAVs) based on optical fiber cables, characterized in that, The unmanned aerial vehicle (UAV) power supply system based on optical fiber and cable according to any one of claims 1 to 10 includes the following steps: S1. The output port (202) of the lightweight flexible high-energy laser transmission optical cable (200) is fixedly connected to the tethering interface (401) of the UAV (400) through the tethering mechanism (300) to establish an optical link from the power supply station (100) to the UAV (400); S2. Start the high-power continuous laser (110) of the power supply station (100), and transmit the high-energy laser beam to the photoelectric conversion unit (410) of the UAV (400) through the lightweight flexible high-energy laser transmission optical cable (200). S3, the photoelectric conversion unit (410) converts the received laser energy into DC power in real time, and after being processed by the power management module (420), it directly drives the motors and flight control system of the UAV (400); S4. During the flight operation of the UAV (400), the fiber optic winding and unwinding management device (500) synchronously winds up and unwinds the lightweight flexible high-energy laser transmission optical cable (200) according to the flight status of the UAV (400) to keep it in an appropriate suspension state. S5. When the drone (400) needs to be recovered or the mission ends, control it to fly back to the vicinity of the power station (100) and disconnect the connection between the lightweight flexible high-energy laser transmission cable (200) and the drone (400) through the tethering mechanism (300).

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