Unmanned aerial vehicle charging system and method

Abstract

The invention provides an unmanned aerial vehicle charging system and method, and the system comprises a laser which is vertically connected to a mobile platform, and a laser control unit which is electrically connected with the laser and can respond to a charging request of an unmanned aerial vehicle. The battery array, the laser image acquisition unit, the light spot positioning unit and the laser receiving end control unit are connected with the unmanned aerial vehicle, the battery array receives laser and converts the laser into electric energy for charging, the center of the battery array is provided with a hollow area for embedding the laser image acquisition unit for coarse alignment, and the laser image acquisition unit acquires laser images; the light spot positioning unit comprises a plurality of detectors which take the hollow area as the center and are symmetrically arranged at the edge of the battery array, and the detectors detect the position deviation of the light spots for fine alignment; and the laser receiving end control unit is in communication connection with the laser image acquisition unit, the light spot positioning unit and the unmanned aerial vehicle flight control system. The device has the beneficial effects that the alignment precision is improved through two-stage positioning, and the conversion efficiency is improved through vertical emission of laser beams.

Description

Technical Field

[0001] This invention belongs to the field of laser wireless charging technology for drones, and in particular relates to a drone charging system and method. Background Technology

[0002] In existing technologies, the collaborative operation of drones and unmanned vehicles has been widely used in logistics distribution, border patrol, agricultural plant protection and other fields. Drones usually provide unmanned vehicles with high-altitude image transmission services to assist unmanned vehicles in path planning and environmental perception. During the collaborative operation, drones need to fly in the area above unmanned vehicles for a long time. Traditional laser wireless charging relies on an APT (Aim, Target, Track) system for energy transmission. This involves a ground-based transmitter using a high-precision two-dimensional turntable to adjust the laser beam direction. However, due to mechanical limitations, the turntable cannot achieve a perfectly vertical zenith angle (90°), with a maximum elevation angle typically only 85°. This results in a 5-10° blind spot directly above the laser beam, particularly problematic in drone-vehicle collaborative scenarios. The drone is usually directly above the vehicle, and the laser beam, due to mechanical limitations, cannot be projected vertically, creating an incident angle with the receiving surface. This causes cosine effect losses in laser wireless charging, significantly reducing transmission efficiency. Furthermore, traditional turntables, due to their large mechanical inertia (response delay of hundreds of milliseconds), struggle to track high-speed moving targets in real-time, leading to tracking errors and energy transmission interruptions. Optoelectronic tracking turntable systems are complex and expensive, making them unsuitable for low-cost collaborative operation scenarios. Therefore, using a high-precision turntable for drone-vehicle collaborative laser wireless charging in such scenarios presents technical challenges, including the inability to achieve vertical charging and high system costs. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a drone charging system and method, which is particularly suitable for application scenarios requiring drones to perform collaborative operations and be charged efficiently above unmanned vehicles.

[0004] The technical solution adopted in this invention is as follows: a drone charging system, including a laser emitting module, which includes a laser connected to a mobile platform and a laser control unit electrically connected to the laser. The laser's emission direction is perpendicular to the ground, and the laser control unit responds to the drone's charging request; an airborne laser receiving module, which includes a battery array connected to the drone, a laser image acquisition unit, a spot positioning unit, and a laser receiving end control unit; the battery array is used to receive the laser and convert it into electrical energy to charge the drone, and the center of the battery array has a hollow area to embed the laser image acquisition unit; the laser image acquisition unit is used to acquire laser position images; the spot positioning unit includes multiple detectors, which are symmetrically arranged around the hollow area on the edge of the battery array, and the detectors are used to detect spot position deviations for precise alignment; the laser receiving end control unit is communicatively connected to the laser image acquisition unit, the spot positioning unit, and the drone flight control system.

[0005] Furthermore, the detector is a photodiode, with multiple photodiodes divided into four groups and arranged in a cross-shaped symmetrical array centered on the hollowed-out area.

[0006] Furthermore, a bandpass filter is provided on the surface of the photodiode.

[0007] Furthermore, the laser image acquisition unit includes a high-speed camera embedded in the hollowed-out area, and its lens surface is provided with a band-blocking filter.

[0008] Furthermore, the laser emits wavelengths in the range of 680nm-1100nm, and the detection surface of the detector is coplanar with the surface of the battery array.

[0009] Furthermore, the present invention also provides a method for charging a drone, comprising the following steps:

[0010] When the drone's battery level is below the threshold, the drone sends a charging request command to the laser control unit;

[0011] The laser control unit responds to the charging request command and controls the laser to emit a laser beam. The laser image acquisition unit acquires the laser position image. The laser receiver control unit calculates the pixel offset between the laser spot center and the image center based on the laser position image, which is used for visual coarse alignment or photoelectric signal-based fine alignment. After alignment, the battery array receives the laser to charge, and the alignment status is monitored during the charging process.

[0012] Furthermore, the laser control unit can inject current exceeding the operating threshold into the laser to emit a low-power alignment laser beam. After alignment is completed by the low-power alignment laser beam, the laser control unit increases the current injected into the laser to switch from the alignment mode to the high-power charging mode.

[0013] Furthermore, the visual coarse alignment step includes: when the pixel offset is greater than a first preset standard value, generating a distance error according to the pixel-distance conversion formula to form a first movement command, and transmitting the first movement command to the UAV flight control system for coarse alignment.

[0014] Furthermore, the pixel-to-distance conversion formula is:

[0015] ;

[0016] ;

[0017] Among them, l x l y , respectively, represent the offset distances in the x and y directions, and h is the flight altitude of the UAV relative to the top of the mobile platform. and These are the field of view angles in the x and y directions of the high-speed camera in the laser image acquisition unit, respectively. and These represent the pixel position values ​​in the x and y directions of the pixel at the center of the captured image, respectively. and These are the pixel position values ​​at the center of the laser in the captured image. and These represent the total number of pixels in the x and y directions of the captured image, respectively.

[0018] Furthermore, the steps for precise alignment based on photoelectric signals include:

[0019] When the pixel offset is not greater than the first preset standard value, the relative current difference of the photocurrent signals detected by multiple detectors deployed in the four quadrants outside the battery array is calculated as follows:

[0020] ΔI x = I1 - I3;ΔI y = I2 - I4;

[0021] When 2|ΔI x | / (I1 +I3) or 2|ΔI y When | / ( I2 + I4) is not less than the second preset standard value, the UAV flight control system moves along the corresponding direction with a fixed step value to achieve precise alignment.

[0022] The advantages and positive effects of this invention are as follows: by adopting the above technical solution, the system cost can be reduced; the laser wireless charging alignment accuracy in the UAV-unmanned vehicle cooperative mobile scenario can be improved through dual-level positioning; and the vertical emission of laser beams can improve conversion efficiency. It has the advantages of simplified structure, reduced system cost, and improved conversion efficiency. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a laser emitting module in one embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of an airborne laser receiving module in one embodiment of the present invention;

[0025] Figure 3 This is a flowchart illustrating a laser wireless charging process according to an embodiment of the present invention;

[0026] In the picture:

[0027] 1. Mobile platform; 2. Drone; 3. Laser; 4. Laser control unit; 5. Battery array; 6. Laser image acquisition unit; 7. Spot positioning unit; 8. Laser receiver control unit. Detailed Implementation

[0028] The embodiments of the present invention will now be described with reference to the accompanying drawings. The described embodiments are only some embodiments of the invention, and not all embodiments.

[0029] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar units or units having the same or similar functions throughout.

[0030] The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In the description of the present invention, it should be understood that terms such as "installation," "connection," and "fixing" should be interpreted broadly, and can refer to direct connection, installation, or fixing, or indirect connection, installation, or fixing. The present invention does not impose any limitations in this regard.

[0031] like Figures 1 to 3The diagram illustrates an embodiment of a drone charging system according to the present invention. It includes a laser emitting module comprising a laser 3 connected to a mobile platform 1 and a laser control unit 4 electrically connected to the laser 3. The laser 3 emits energy perpendicular to the ground. The laser control unit 4 responds to charging requests from the drone 2. An airborne laser receiving module includes a battery array 5 connected to the drone 2, a laser image acquisition unit 6, a spot positioning unit 7, and a laser receiving control unit 8. The battery array 5 receives the laser and converts it into electrical energy to charge the drone 2. The battery array 5 has a hollowed-out area at its center to embed the laser image acquisition unit 6. The laser image acquisition unit 6 acquires images of the laser's position. The spot positioning unit 7 includes multiple detectors symmetrically arranged around the hollowed-out area at the edge of the battery array 5. The detectors detect spot position deviations for precise alignment. The laser receiving control unit 8 is communicatively connected to the laser image acquisition unit 6, the spot positioning unit 7, and the drone flight control system. Preferably, the mobile platform 1 is an unmanned vehicle that moves in coordination with the drone. The laser 3 is vertically mounted on the mobile platform 1 to emit a laser beam vertically. In this embodiment, the laser 3 is vertically mounted on the top plane of the unmanned vehicle. The laser control unit 4 can provide the laser 3 with an adjustable constant current power supply. The laser receiver control unit 8 is configured to perform two-stage alignment control, which includes coarse alignment and fine alignment. In the coarse alignment stage, based on the laser position image captured by the laser image acquisition unit 6, a horizontal movement command for the drone is generated for coarse alignment. When the laser spot is located at the center of the image, the fine alignment stage begins, where a fine adjustment command for the drone is generated by comparing the photocurrent signal of the laser spot positioning unit 7 for fine alignment.

[0032] By employing dual-stage alignment, rapid and precise alignment is achieved during the coordinated movement of the mobile platform 1 and the drone 2. A laser 3, perpendicular to the mobile platform 1, replaces the traditional high-precision two-dimensional turntable, solving the problems of blind spots at the top of the traditional turntable that prevent vertical pointing and response delays due to mechanical inertia. The laser beam can be projected vertically onto the battery array 5, improving energy conversion efficiency and reducing system costs, making it suitable for widespread application. Through the laser image acquisition unit 6 embedded in the center of the battery array 5, coaxial visual tracking is achieved, solving the bottleneck of aiming accuracy and reducing the risk of energy transmission interruption or tracking misalignment. This is particularly suitable for applications such as logistics delivery and border patrol where the drone 2 needs to follow moving targets (such as vehicles or ships) for coordinated movement and requires continuous dynamic charging.

[0033] In this embodiment, the detector is a photodiode. Multiple photodiodes are divided into four groups and arranged in a cross-shaped symmetrical array centered on the hollowed-out area. Specifically, the four groups of photodiodes are symmetrically arranged in the four quadrants (up, down, left, right) of the edge of the battery array 5. When the light spot is located at the center of the image, the fine alignment stage begins. By comparing the photocurrent signals of the four groups of photodiodes, a fine-tuning command for the UAV is generated until the photocurrent difference in the four quadrants is below a threshold. Preferably, the installation position of the photodiodes satisfies the following conditions: 1-2 mm from the edge of the battery array 5, and adjacent groups of photodiodes are distributed at 90° intervals. When the laser spot deviates from the center, the photocurrent difference between the photodiodes generates a correction vector. The UAV flight control system uses this vector to drive the UAV 2 to move for fine-tuning, achieving precise alignment between the UAV 2 and the laser beam.

[0034] A bandpass filter is provided on the surface of the photodiode. The bandpass filter is configured to transmit a specific wavelength of laser light emitted by the laser while suppressing interference from ambient stray light. The bandpass filter only allows the wavelength emitted by the laser 3 (such as a specific wavelength in the range of 680nm-1100nm) to pass through. Preferably, the bandpass filter only allows the wavelength emitted by the laser 3 (such as 808nm or 1064nm in the range of 780nm-1100nm) to pass through, while blocking noise generated by other light sources such as sunlight and artificial light. For example, when a drone flies under direct sunlight, ambient light may overwhelm the weak photoelectric signal. By using the bandpass filter, the photodiode responds only to the laser wavelength, significantly improving the signal-to-noise ratio and detection accuracy. This ensures that the photocurrent signal is stable and reliable during the alignment stage, not only improving the system's anti-interference capability but also reducing the risk of misjudgment, enabling the drone to maintain high positioning accuracy even under complex lighting conditions.

[0035] In this embodiment, the laser image acquisition unit 6 includes a high-speed camera embedded in the hollowed-out area, and its lens surface is provided with a band-blocking filter. Preferably, the frame rate of the high-speed camera is not less than 200fps. The high-speed camera, each photodiode, and the UAV flight control system are respectively connected to the laser receiver control unit 8. The lens size of the high-speed camera matches the hollowed-out area and is embedded therein. Preferably, the diameter of the hollowed-out area of ​​the battery array 5 is 1.05-1.2 times the outer diameter of the high-speed camera lens, and the distance between the hollowed-out edge and the outer wall of the lens is ≤1mm. The detection surface of the photodiode, which serves as a detector, is coplanar with the surface of the battery array 5. The high-speed camera is embedded in the center of the battery array 5 to achieve coaxial visual tracking. The optical axis of the camera coincides with the normal of the laser receiving surface, eliminating parallax errors and improving alignment accuracy. High-speed camera lenses are equipped with light-blocking filters that can significantly attenuate or block specific laser wavelengths used for energy transmission (a specific wavelength in the 780nm-1100nm range, such as 808nm or 1064nm lasers). This avoids image overexposure caused by high-power lasers, improves the accuracy of spot recognition, prevents lens glare or image saturation caused by the laser beam itself, and preserves environmental details for auxiliary positioning. This ensures the accurate operation of the spot center extraction algorithm, making it particularly suitable for dynamic tracking during high-speed movement and reducing alignment failures caused by poor image quality.

[0036] Laser 3 emits a specific wavelength within the 680nm-1100nm band, preferably a specific wavelength within the 780nm-1100nm band, such as 808nm or 1064nm. This approach balances atmospheric transmission efficiency, photoelectric conversion efficiency, and high emission power. In particular, 808nm and 1064nm fall within the atmospheric window, enabling long-distance energy transmission with minimal attenuation. Furthermore, photovoltaic cells such as gallium arsenide exhibit high photoelectric conversion efficiency in this band (e.g., 808nm corresponds to the peak response of gallium arsenide cells), improving charging efficiency. In collaborative operations between mobile platforms and drones, this wavelength selection ensures the stability and safety of energy transmission while reducing overall system power consumption, achieving low-cost, high-efficiency laser charging.

[0037] On the other hand, the present invention also provides a method for charging a drone, comprising the following steps:

[0038] When the battery level of drone 2 is below the threshold, drone 2 sends a charging request command to laser control unit 4;

[0039] The laser control unit 4 responds to the charging request command and controls the laser 3 to emit an alignment laser beam. At the same time, the laser image acquisition unit 6 acquires the laser position image. The laser receiver control unit 8 calculates the pixel offset between the center of the laser position and the center of the image based on the laser position image, so as to perform visual coarse alignment or trigger fine alignment based on photoelectric signals.

[0040] Alternatively, in another optimized embodiment, the laser control unit 4 responds to a charging request command by first acquiring a laser position image based on the laser image acquisition unit 6 to complete coarse alignment. After visual coarse alignment, the laser control unit 4 receives a fine alignment command and controls the laser 3 to emit a laser beam for fine alignment. After alignment, the battery array 5 receives the laser to charge, and the alignment status is monitored during the charging process.

[0041] Preferably, the laser control unit 4 can inject a current exceeding the operating threshold into the laser 3 to emit a low-power alignment laser beam. After alignment is completed using the low-power alignment laser beam, the laser control unit 4 receives a charging mode command and increases the current of the laser 3 to a preset charging power, switching from the alignment mode to the high-power charging mode. This graded power control mechanism ensures the safety of the charging process, first using a low-power laser for precise alignment, and then proceeding with high-power charging, making it particularly suitable for dynamic charging needs in mobile scenarios.

[0042] The steps of visual coarse alignment include: when the pixel offset is greater than a first preset standard value, generating a distance error according to the pixel-distance conversion formula to form a first movement command, transmitting the first movement command to the UAV flight control system, and the UAV flight control system controlling the UAV to move according to the first movement command for coarse alignment. In this embodiment, the first preset standard value is 10 pixels.

[0043] The pixel-to-distance conversion formula is:

[0044] Formula 1 ;

[0045] Formula 2 ;

[0046] Among them, l x l y , respectively, represent the offset distances in the x and y directions, and h is the flight altitude of UAV 2 relative to the top of mobile platform 1. and These are the field of view angles in the x and y directions of the high-speed camera of the laser image acquisition unit 6, respectively. and These represent the pixel position values ​​in the x and y directions of the pixel at the center of the captured image, respectively. and These are the pixel position values ​​at the center of laser 3 in the captured image. and These represent the total number of pixels in the x and y directions of the captured image, respectively.

[0047] The pixel-to-distance conversion formula transforms image information into actual distance instructions, establishing a precise mapping relationship between visual perception and physical location, and achieving reliable and rapid coarse alignment.

[0048] The steps for precise alignment based on photoelectric signals include:

[0049] When the pixel offset is not greater than the first preset standard value, the light spot is located in the center region of the image. The relative current difference of the photocurrent signals detected by multiple detectors deployed in the four quadrants around the outer edge of the battery array 5 is calculated as follows:

[0050] Formula 3 ΔI x = I1 - I3;

[0051] Formula 4 ΔI y = I2 - I4;

[0052] Formula 3 is used for horizontal correction, and Formula 4 is used for vertical correction.

[0053] When 2|ΔI x | / (I1 +I3) or 2|ΔI y When | / (I2 + I4) is not less than the second preset standard value, the UAV flight control system controls the UAV to move along the corresponding direction by a fixed step value for precise alignment. In this embodiment, the second preset standard value is 5%, and the fixed step value is 1cm.

[0054] The dual-stage alignment mechanism combines the speed of visual alignment with the precision of photoelectric alignment. In the coarse alignment stage, the wide field of view of the high-speed camera is used for rapid positioning, while in the fine alignment stage, four-quadrant photodiodes are used to adjust the precision. The multi-stage alignment ensures accuracy while improving response speed.

[0055] In a specific application scenario:

[0056] The system consists of: a 400W laser 3 with a wavelength of 808nm vertically mounted on the top of the mobile platform 1; the laser 3 integrates a laser control unit 4 with a constant current adjustment range of 0-40A; and a gallium arsenide laser receiver battery array 5 mounted on the bottom of the drone 2. The center of the battery array 5 has a 20mm*20mm cutout and embeds a 5-megapixel high-speed camera with a frame rate of 500fps. Four photodiodes are arranged along the edge of the battery array 5.

[0057] Charging request trigger: When the battery level of drone 2 drops to 20%, it sends a charging request and real-time coordinates to the unmanned vehicle, which is the mobile platform 1, via the 2.4GHz channel.

[0058] Coarse alignment stage: The laser control unit 4 receives a charging request command. The high-speed camera of the laser image acquisition unit 6 captures an image of the laser's position. The laser receiver control unit 8 calculates the offset between the center of the laser's position and the center of the image. If the pixel offset is ≥10, a distance error is generated according to the pixel-distance conversion formula, forming the first movement command and transmitting it to the UAV flight control system for coarse alignment.

[0059] Precision alignment stage: When the pixel offset is <10, the laser control unit 4 receives the precision alignment request command, turns on the laser 3 and inputs a current of 10A. The laser 3 emits a laser power of about 20W and reads the four-quadrant photocurrent value. If the difference between the four-quadrant photocurrent is ≥5%, a command is generated to move the relative position of the drone 2 by 1cm on the x-axis or y-axis. After the four-quadrant current is balanced (the difference between the four-quadrant photocurrent is <5%), the laser power is increased to 400W to enter the efficient laser wireless charging mode.

[0060] The various units (high-speed camera, photodiode, laser receiver control unit 8, etc.) communicate reliably via an onboard internal bus. The communication between the UAV 2 and the mobile platform 1 (such as an unmanned vehicle) adopts a mature wireless communication protocol to transmit charging requests, status information, and necessary control commands. The laser control unit 4 can dynamically adjust the injection current of the laser 3 according to the commands received through the communication link, thereby achieving a safe and smooth switching between low-power "alignment mode" and high-power "charging mode". It is understood that the specific mechanical structure assembly and communication interaction can be flexibly designed based on the technical knowledge of those skilled in the art, as long as the real-time response and structural stability of the system are ensured. This invention does not impose any limitations.

[0061] This invention enables precise charging while in motion. An unmanned vehicle (UAV) serves as the mobile platform 1, equipped with a laser 3. A UAV 2 integrates a laser receiving module at its bottom, sharing position, speed, and attitude data in real time via two-way communication. When the UAV 2's battery level falls below a threshold, it sends a charging request to the UAV. When precise alignment is required, the laser emission module is activated, increasing laser emission power after alignment for efficient charging. The laser emits vertically upwards, with the UAV 2 hovering directly above the UAV, ensuring zero-incident angle transmission and eliminating zenith angle limitations. The motion states of the UAV and UAV can be dynamically adjusted, forming coordinated motion compensation. A hollowed-out battery array 5, combined with a four-quadrant detector and a high-speed camera, implements a two-stage alignment strategy for rapid and precise energy transfer.

[0062] The embodiments of the present invention have been described in detail above, but the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A drone charging system, characterized in that, include: A laser emitting module includes a laser connected to a mobile platform and a laser control unit electrically connected to the laser. The laser emits energy in a direction perpendicular to the ground, and the laser control unit responds to a charging request from a drone. An airborne laser receiver module, which includes a battery array connected to the UAV, a laser image acquisition unit, a spot positioning unit, and a laser receiver control unit; The battery array is used to receive laser light and convert it into electrical energy to charge the drone. The center of the battery array has a hollow area to embed the laser image acquisition unit. The laser image acquisition unit is used to acquire laser position images; The light spot positioning unit includes multiple detectors, which are symmetrically arranged around the hollow area on the edge of the battery array. The detectors are used to detect the positional deviation of the light spot for precise alignment. The laser receiver control unit is communicatively connected to the laser image acquisition unit, the spot positioning unit, and the UAV flight control system.

2. The drone charging system according to claim 1, characterized in that: The detector is a photodiode, and multiple photodiodes are divided into four groups and arranged in a cross-shaped symmetrical array with the hollowed-out area as the center.

3. The drone charging system according to claim 2, characterized in that: The photodiode is provided with a bandpass filter on its surface.

4. The drone charging system according to claim 1, characterized in that: The laser image acquisition unit includes a high-speed camera embedded in the hollowed-out area, and its lens surface is provided with a light-blocking filter.

5. The drone charging system according to any one of claims 1-4, characterized in that: The laser emits wavelengths in the range of 680nm-1100nm, and the detection surface of the detector is coplanar with the surface of the battery array.

6. A method for charging a drone, utilizing the drone charging system according to any one of claims 1-5, characterized in that, Includes the following steps: When the drone's battery level is below a threshold, the drone sends a charging request command to the laser control unit; The laser control unit responds to the charging request command and controls the laser to emit a laser beam. The laser image acquisition unit acquires the laser position image. The laser receiver control unit calculates the pixel offset between the laser position and the image center based on the laser position image for visual coarse alignment or fine alignment based on photoelectric signals. After alignment, the battery array receives the laser to charge, and the alignment status is monitored during the charging process.

7. The drone charging method according to claim 6, characterized in that, The laser control unit can inject current exceeding the operating threshold into the laser to emit a low-power alignment laser beam. After alignment is completed by the low-power alignment laser beam, the laser control unit increases the current injected into the laser to switch from alignment mode to high-power charging mode.

8. The drone charging method according to claim 6, characterized in that, The steps of the visual coarse alignment include: When the pixel offset is greater than the first preset standard value, a distance error is generated according to the pixel-distance conversion formula to form a first movement command, and the first movement command is transmitted to the UAV flight control system for coarse alignment.

9. The drone charging method according to claim 8, characterized in that, The pixel-to-distance conversion formula is: ； ； Among them, l x l y , respectively, represent the offset distances in the x and y directions, and h is the flight altitude of the UAV relative to the top of the mobile platform. and These are the field of view angles in the x and y directions of the high-speed camera of the laser image acquisition unit, respectively. and These represent the pixel position values ​​in the x and y directions of the pixel at the center of the captured image, respectively. and These are the pixel position values ​​at the center of the laser in the captured image. and These represent the total number of pixels in the x and y directions of the captured image, respectively.

10. The drone charging method according to claim 6, characterized in that, The photoelectric signal-based precision alignment steps include: When the pixel offset is not greater than the first preset standard value, the relative current difference of the photocurrent signals detected by the multiple detectors deployed in the four quadrants outside the battery array is calculated as follows: ΔI x = I1 - I3;ΔI y = I2 - I4; When 2|ΔI x | / (I1 +I3) or 2|ΔI y When | / (I2 + I4) is not less than the second preset standard value, the UAV flight control system moves along the corresponding direction with a fixed step value to achieve precise alignment.

Images