Quadrotor unmanned aerial vehicle with wake flow and attitude loose coupling characteristic

Abstract

The invention relates to the technical field of unmanned aerial vehicle aerodynamics, in particular to a four-rotor unmanned aerial vehicle with wake flow and attitude loose coupling characteristics, the four-rotor unmanned aerial vehicle comprises a fuselage and a plurality of rotor assemblies connected with the fuselage, a flight control system, a visual sensor and an attitude sensor are arranged in the fuselage, and each rotor assembly comprises a rotor, a duct and a flow deflector; the duct surrounds the rotor wings, and the radius of the duct is gradually reduced in the airflow direction; the flow deflector is connected outside the duct air outlet; each flow deflector sequentially comprises a starting section, a transition section and a flow guide section in the airflow direction; the starting section and the diversion section are planes, the transition section is a curved surface, and the track of the curved surface is a Bezier curve; the flight control system can adjust the included angle between the flow guide section of the flow guide piece and the ground. The invention further relates to a design method of the flow deflector of the unmanned aerial vehicle and a photovoltaic panel cleaning method adopting the unmanned aerial vehicle. The air flow direction in the photovoltaic panel cleaning process can be optimized, and energy loss is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle (UAV) aerodynamics, and in particular to a four-rotor UAV with loosely coupled wake and attitude characteristics. Background Art

[0002] In recent years, multi-rotor drones have been widely used in a variety of fields, including environmental monitoring, inspections, logistics and transportation, and agricultural plant protection. In particular, they have become an efficient automated cleaning solution for photovoltaic panel cleaning due to their high maneuverability and flexible operation. Currently, pollutants such as dust and bird droppings easily accumulate on the surface of photovoltaic panels, affecting the efficiency of photoelectric conversion. The airflow blown out by the drone's rotors can be used to clean the surface of photovoltaic panels, thereby improving the efficiency of photovoltaic power generation. However, in existing technologies, the direction of the airflow is directly affected by the change in the drone's posture, making it difficult to control the angle of the airflow, resulting in unstable cleaning effects. In addition, since the wake generated by the rotor usually has strong turbulent characteristics, energy loss is relatively large during the propagation process, further reducing the cleaning efficiency of the airflow.

[0003] In existing photovoltaic panel cleaning drone designs, there are two main ways to optimize airflow direction and cleaning effect: (1) Adjusting the wake direction through flight attitude. However, when the drone performs complex maneuvers, the wake direction will still be disturbed, resulting in unstable cleaning efficiency. Frequent adjustment of flight attitude will also increase energy consumption and shorten the drone's flight time. (2) Using an air guide structure to optimize airflow direction. However, the air guide cover of this design is usually a fixed structure and cannot adapt to different cleaning angle requirements. At the same time, it does not consider the energy loss of the airflow, which may reduce the effective range of the airflow. In addition, the design of a fixed air guide cover may increase the weight of the drone and affect its flight performance. Summary of the Invention

[0004] In view of the above problems, the present invention provides a four-rotor drone with loosely coupled wake and attitude characteristics, which solves the technical problems of the need to optimize the direction of airflow and energy loss during the photovoltaic panel cleaning process in the prior art.

[0005] In one aspect, the present invention provides a quadrotor drone with loosely coupled wake and attitude characteristics, comprising: a fuselage and a plurality of rotor assemblies connected to the fuselage, characterized in that:

[0006] The fuselage is provided with a flight control system, a visual sensor, and an attitude sensor, and the rotor assembly includes a rotor 2, a duct 3, and a guide vane 1;

[0007] The duct 3 surrounds the rotor 2, and the radius of the duct 3 gradually decreases along the direction of the airflow; the fuselage is connected to an arm 4, and the arm 4 extends to the inside of the duct 3, and the guide vane 1 is connected to the arm 4 and extends out of the air outlet of the duct 3; the guide vane 1 includes a starting section, a transition section and a guide section in sequence along the direction of the airflow; the starting section and the guide section are planes, the transition section is a curved surface, and the trajectory of the curved surface is a Bezier curve; the flight control system can adjust the angle between the guide section of the guide vane 1 and the ground.

[0008] Preferably, the angle θ between the guide section and the photovoltaic panel is 10° to 40°, and the optimal angle between the guide section and the photovoltaic panel is 20°; the angle between the photovoltaic panel and the ground is 37°.

[0009] Preferably, the fuselage is made of carbon fiber plates; the visual sensor is one or more cameras, and the posture sensor is used to obtain the movement posture of the fuselage; the guide plate 1 is made of TPU soft rubber material 3D printing and has a thickness of 5mm; the diameter of the duct 3 is 118.24mm.

[0010] In one aspect, the present invention provides a method for designing a deflector for a quadrotor drone with loosely coupled wake and attitude characteristics, comprising the following steps:

[0011] The point where the starting section and the transition section of the guide plate intersect is set as the first control point, the point where the transition section and the guide section intersect is set as the second control point, and the position of the third control point is adjusted so that when the starting section is perpendicular to the ground, the angle between the guide section and the photovoltaic panel is the optimal angle.

[0012] Preferably, the method for obtaining the optimal angle includes the following steps:

[0013] (1) The angle between the photovoltaic panel and the ground is controlled to be 37°, and dry standard sand with a particle size of 0.25-150 μm is evenly laid on the photovoltaic panel;

[0014] (2) Hover the drone without guide vanes above the photovoltaic panel, adjust the drone's attitude, and adjust the angle between the drone's rotor airflow and the photovoltaic panel. After cleaning, take an image of the dust remaining on the photovoltaic panel and weigh it to obtain the weight of the dust remaining on the photovoltaic panel.

[0015] (3) using an image processing method to obtain the dust area ratio of the photovoltaic panel, and obtaining the dust removal rate based on the residual dust weight;

[0016] (4) The angle between the rotor airflow and the photovoltaic panel that maximizes the dust removal rate and minimizes the dust area is determined as the optimal angle.

[0017] In one aspect, the present invention provides a photovoltaic panel cleaning method based on a quadrotor drone with loosely coupled wake and attitude characteristics, comprising the following steps:

[0018] Step S1: Perform a self-check on the UAV and set the mission area position and guide vane inclination angle;

[0019] Step S2: The UAV drives to the mission area and obtains the positions of multiple photovoltaic panels based on the images captured by the visual sensor;

[0020] Step S3: Based on the multiple photovoltaic panel positions, an optimal flight path is generated using a path planning strategy, where the optimal flight path passes through all photovoltaic panel positions;

[0021] Step S4: The drone cleans each photovoltaic panel along the optimal flight path. During cleaning, the guide vane is adjusted using a PID control algorithm based on the data from the visual sensor and the attitude sensor so that the angle between the guide section of the guide vane and the photovoltaic panel is the optimal angle.

[0022] Preferably, step S3 specifically includes:

[0023] Step S3-1, obtaining the position and attitude information of the UAV by the attitude sensor;

[0024] Step S3-2: Input the multiple photovoltaic panel positions and the position and attitude information of the drone into a path planning algorithm to generate an optimal flight path passing through all photovoltaic panel positions.

[0025] Preferably, the specific steps of cleaning in step S4 include:

[0026] (1) Arriving above the photovoltaic panel, the visual sensor and attitude sensor obtain the position, tilt angle and rotation direction of the aircraft;

[0027] (2) calculating the deviation between the angle between the guide section of the current guide plate and the photovoltaic panel and the optimal angle based on the current photovoltaic panel position and the position, tilt angle and rotation direction of the fuselage;

[0028] (3) Based on the deviation, a PID control algorithm is used to calculate the corresponding control signal in real time according to the preset proportional, integral and differential parameters, and the deflection angle of the guide vane is adjusted in real time.

[0029] Preferably, the following steps are also included

[0030] Step S5: After completing the cleaning of all photovoltaic panels, the drone returns to the starting position;

[0031] Step S6: Record the cleaning task data and upload the cleaning task data to the cloud for storage.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] (1) The quadrotor drone provided by the present invention has loosely coupled wake and attitude characteristics and is equipped with ducts and adjustable guide vanes. Through the synergistic effect of the ducts and the adjustable guide vanes, the direction of the rotor wake is made more stable and no longer completely dependent on the flight attitude of the drone. This allows the airflow to act more stably on the surface of the photovoltaic panel, improving the cleaning effect. This solves the problem in the prior art of unstable airflow angle caused by changes in the drone's flight attitude, making the photovoltaic panel cleaning operation more precise.

[0034] (2) The present invention utilizes a Bezier curve-based deflector cross-section design, which effectively reduces energy loss as air flows through the deflector, thereby expanding the effective range of the wake. Compared to traditional fixed air deflectors, the optimized deflector design guides airflow more efficiently, reduces ineffective losses, achieves a wider range, and achieves more uniform cleaning coverage, thus improving overall cleaning efficiency.

[0035] (3) Because the wake direction of the present invention is primarily guided by the guide vanes, the drone can achieve efficient cleaning without frequently adjusting its flight attitude, thereby reducing the additional energy consumption caused by attitude adjustments and improving its endurance. Existing solutions rely on the drone's attitude adjustment to optimize the airflow direction, while the solution of the present invention can maintain efficient cleaning effects with fewer attitude changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings are only for purposes of illustrating particular embodiments and are not to be considered limiting of the invention.

[0037] Figure 1 A top view of the quadrotor drone with loosely coupled wake and attitude provided by the present invention.

[0038] Figure 2 Schematic diagram of a single rotor structure of a quadrotor UAV with loosely coupled wake and attitude characteristics provided by the present invention.

[0039] Figure 3 This is a schematic diagram of the structure of a quadrotor drone with loosely coupled wake and attitude characteristics provided by the present invention.

[0040] Figure 4 A side view of the quadrotor drone with loosely coupled wake and attitude provided by the present invention.

[0041] Figure 5 This is a schematic diagram of the curvature of the guide vane provided by the present invention.

[0042] Figure 6 This is a schematic diagram of the angle between the guide vane wake and the photovoltaic panel provided by the present invention.

[0043] Figure 7 This is the stress cloud diagram of the guide vane provided by the present invention.

[0044] Figure 8 This is a cloud diagram of the flow velocity of the guide vane wake provided by the present invention.

[0045] Figure 9 This is a flow chart of the steps for obtaining the optimal angle provided by the present invention.

[0046] Figure 10 Flowchart of the photovoltaic panel cleaning method based on a quadrotor drone with loosely coupled wake and attitude characteristics provided by the present invention.

[0047] Reference numerals: 1- guide vane, 2- rotor, 3- duct, 4- arm, 5- battery box, 6- landing gear. DETAILED DESCRIPTION

[0048] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited by the specific embodiments disclosed below.

[0049] In existing technologies, the direction of the wake generated by drone rotors is affected by the flight attitude, resulting in an unstable airflow angle and reduced photovoltaic panel cleaning efficiency. Furthermore, the design of traditional wind deflectors fails to fully consider the attenuation of wake energy, resulting in significant airflow losses during propagation, affecting cleaning effectiveness.

[0050] This invention installs ducts on the outside of each rotor of a quadrotor drone and deploys deflectors at the duct exits. This loosely couples the drone's wake and attitude, reducing the impact of flight attitude on airflow direction. Furthermore, the deflectors employ an optimized curvature design to reduce airflow energy loss within a certain range of deflection angles, thereby improving the efficiency and stability of photovoltaic panel cleaning.

[0051] In order to illustrate the effectiveness of the method proposed in the present invention, the above technical solution of the present invention is described in detail below through a specific embodiment. A specific embodiment of the present invention is as follows. Figure 1 、 Figure 2 As shown, a quadrotor UAV with loosely coupled wake and attitude characteristics is disclosed, comprising: a fuselage and a plurality of rotor assemblies connected to the fuselage;

[0052] The fuselage is provided with a flight control system, a visual sensor, and an attitude sensor, and the rotor assembly includes a rotor 2, a duct 3, and a guide vane 1;

[0053] The duct 3 surrounds the rotor 2, and the radius of the duct 3 gradually decreases along the direction of the airflow; the fuselage is connected to an arm 4, and the arm 4 extends to the inside of the duct 3, and the guide vane 1 is connected to the arm 4 and extends out of the air outlet of the duct 3; the guide vane 1 includes a starting section, a transition section and a guide section in sequence along the direction of the airflow; the starting section and the guide section are planes, the transition section is a curved surface, and the trajectory of the curved surface is a Bezier curve; the flight control system can adjust the angle between the guide section of the guide vane 1 and the ground.

[0054] like Figure 3 、 Figure 4 As shown, the fuselage is connected to the rotor assembly via an arm 4, and a battery box 5 and a landing gear 6 are also fixed on the fuselage.

[0055] In some embodiments, the entire fuselage is made of lightweight, high-strength carbon fiber panels, and a battery compartment may be provided inside. The visual sensor is one or more cameras that can capture images of the photovoltaic panels under the drone, and the attitude sensor can obtain the movement attitude of the fuselage.

[0056] In some embodiments, the duct 3 is made of lightweight high-strength material, the shape of the duct is optimized by fluid dynamics, and the radius of the duct 3 gradually decreases along the airflow direction, which can reduce additional resistance and improve airflow stability; the diameter of the duct 3 is 118.24 mm.

[0057] In some embodiments, the guide vane 1 guides the direction of the airflow so that the downwash airflow forms a suitable angle with the surface of the photovoltaic panel as much as possible to improve the cleaning efficiency; each rotor assembly is provided with a guide vane.

[0058] In some embodiments, rotor 2 is driven by an electric motor, using a brushless motor to drive high-efficiency blades, and a ducted structure to improve thrust efficiency and reduce the impact of turbulence; the rotation speed of rotor 2 is 25530RPM.

[0059] In some embodiments, the flight control system can adjust the motor speed to control the flow rate in the duct, and the flight control system can adjust the angle of the guide vane so that the angle between the guide vane and the photovoltaic panel is the optimal angle, thereby improving the cleaning efficiency of the photovoltaic panel and improving energy utilization.

[0060] In some embodiments, the deflector 1 is 3D-printed from a flexible TPU soft-rubber material. Even if the drone's posture changes during flight, the deflector can flexibly adjust its angle through a single-point control method, directing airflow along the surface of the photovoltaic panel, ensuring that the cleaning effect is not affected by the drone's posture changes.

[0061] The present invention provides a design method for a guide vane of a quadrotor drone with loosely coupled wake and attitude characteristics.

[0062] In order to minimize the flow loss caused by the deflection of the rotating shaft when the UAV airflow passes through the guide vane, the present invention designs the curved surface shape of the guide vane transition section according to the flow conditions of the airflow, so that the airflow can change direction more smoothly.

[0063] like Figure 5 As shown, specifically, the present invention selects three control points as the basis to establish a guide plate transition section model, wherein the point where the starting section and the transition section intersect is set as the first control point, and the point where the transition section and the guide section intersect is set as the second control point. The position of the third control point is adjusted so that when the starting section is perpendicular to the ground, the angle between the guide section and the photovoltaic panel is the optimal angle.

[0064] In some embodiments, the cross section of the guide plate is modeled and divided into three parts: a starting section, a transition section, and a guide section. Considering a series of inherent properties of the material such as strength and stiffness, the thickness of the guide plate is set to 5 mm.

[0065] In some embodiments, the angle between the wake and the photovoltaic panel can be in the range of θ=10° to 40°, such as Figure 6 shown.

[0066] In some embodiments, the optimal angle between the wake and the photovoltaic panel is 20°.

[0067] The method for obtaining the optimal angle includes the following steps: Figure 9 As shown:

[0068] (1) The angle between the photovoltaic panel and the ground is controlled to be 37°, and dry standard sand with a particle size of 0.25-150 μm is evenly laid on the photovoltaic panel;

[0069] (2) Hover a UAV without a guide vane above the photovoltaic panel and adjust the UAV's attitude so that the airflow from the UAV rotor and the photovoltaic panel form angles of 53°, 40°, 20°, and 0°, respectively. Take images of the residual dust on the photovoltaic panel and weigh them to obtain the weight of the residual dust on the photovoltaic panel.

[0070] (3) using an image processing method to obtain the dust area ratio of the photovoltaic panel, and obtaining the dust removal rate based on the residual dust weight;

[0071] (4) The angle with the highest dust removal rate and the smallest dust area ratio is determined as the optimal angle.

[0072] During the experimental investigation phase, the authors of the present invention collected dust samples from the surface of photovoltaic panels in the northwest region and conducted a detailed analysis of their composition and particle size distribution. The results showed that the dust particles were mainly composed of quartz, albite, montmorillonite, etc., and the particle size range was mostly between 0.25 and 141.58 μm. Based on this, the present invention designed a sand blowing experiment that simulates real working conditions. During the experiment, the angle between the photovoltaic panel and the ground was strictly controlled to be 37°, and dry standard sand with a particle size of 0.25-150 μm was evenly laid on its surface to ensure that the quality of sand used in each experiment was the same. The propeller of the drone maintained a constant speed and moving speed. By adjusting the posture of the drone, four typical angles of 53°, 40°, 20° and 0° between the airflow and the photovoltaic panel were selected for multiple groups of sand blowing experiments. Each group of experiments was repeated three times to ensure the reliability of the data.

[0073] From a theoretical analysis perspective, based on the principles of dust accumulation mechanics, the smaller the angle between the airflow and the photovoltaic panel, the better the cleaning effect should theoretically be. However, in practice, an angle that is too small prevents the airflow from fully impacting the photovoltaic panel surface, resulting in airflow loss. Through actual experiments, the present invention has determined a 20° angle design. This ensures that the airflow effectively impacts the photovoltaic panel surface while also providing sufficient energy to remove dust, achieving an optimal balance between cleaning effect and energy efficiency.

[0074] The present invention analyzes the force and aerodynamics of the guide vane. Figure 7 As shown in the figure, Ansys analysis can obtain the stress cloud diagram formed when the guide vane is subjected to the tension of the connecting rod. It can be seen that the stress in the transition section of the guide vane is uniformly distributed and there is no stress concentration area.

[0075] like Figure 8 As shown in the figure, the aerodynamic simulation of the guide vane is performed in Fluent. Compared with the traditional rotating shaft deflection guide vane, the airflow dissipation in the transition section of the guide vane is small, ensuring that the UAV wake will not be excessively lost and making full use of the clean airflow.

[0076] The present invention also provides a photovoltaic panel cleaning method based on the four-rotor drone with the loose coupling characteristics of wake and attitude. Figure 10 As shown, the following steps are included:

[0077] Step S1: Perform a self-check on the UAV and set the mission area position and guide vane inclination angle;

[0078] In this step, the drone first checks its battery level and sensor status to ensure proper function. The user then sets the PV panel cleaning task, including parameters such as the task area location and deflector angle.

[0079] Step S2: The UAV drives to the mission area and obtains the positions of multiple photovoltaic panels based on the images captured by the visual sensor;

[0080] The drone's onboard computer is equipped with an image recognition algorithm. In this step, the drone uses a convolutional neural network-based image recognition algorithm to identify images captured by the visual sensor and locate the locations of multiple photovoltaic panels that need to be cleaned for subsequent path planning.

[0081] Step S3: Based on the multiple photovoltaic panel positions, an optimal flight path is generated using a path planning strategy, where the optimal flight path passes through all photovoltaic panel positions;

[0082] The drone's onboard computer also integrates a path planning algorithm, which can work with the camera and attitude sensor to plan the cleaning path in real time.

[0083] The drone's position and attitude information is acquired by an attitude sensor, and a path planning algorithm is used to generate an optimal flight path based on the drone's position and attitude information and the positions of the multiple photovoltaic panels. This path planning strategy uses an S-shaped cleaning path to maximize cleaning efficiency.

[0084] Through this method, S-shaped path planning guides the drone to shuttle between adjacent photovoltaic panels, ensuring that the cleaning airflow evenly covers each panel surface. This path planning method not only avoids overlapping cleaning areas but also effectively reduces the drone's flight distance and time during the cleaning process, significantly improving cleaning efficiency. The S-shaped path design also fully considers dust prevention. By optimizing the drone's flight path and cleaning sequence, the possibility of dust generation during the cleaning process is reduced.

[0085] Step S4: The drone cleans each photovoltaic panel along the optimal flight path. During cleaning, the guide vane is adjusted using a PID control algorithm based on the data from the visual sensor and the attitude sensor so that the angle between the guide section of the guide vane and the photovoltaic panel is the optimal angle.

[0086] The flight control system accurately sends control commands to the drone's flight control system based on the optimal flight path generated by the algorithm, ensuring that the drone can fly stably along the planned S-shaped path. After reaching above the photovoltaic panels, the deflector angle is adjusted. The details are as follows:

[0087] (1) Visual sensors and attitude sensors obtain the position, tilt angle, and rotation direction of the fuselage;

[0088] (2) obtaining a deviation between the angle between the guide section of the current guide vane and the photovoltaic panel and the optimal angle based on the current photovoltaic panel position and the position, tilt angle, and rotation direction of the fuselage;

[0089] (3) Based on the deviation, a PID control algorithm is used to calculate the corresponding control signal according to the preset proportional (P), integral (I), and differential (D) parameters to adjust the deflection angle of the guide vane.

[0090] Through this real-time feedback and adjustment mechanism, no matter how the inclination angle of the photovoltaic panel changes, it can ensure that the clean airflow acts on the surface of the photovoltaic panel in the optimal direction and angle, thereby achieving efficient cleaning.

[0091] After completing the cleaning of a single photovoltaic panel using the above method, the drone is controlled to automatically move to the next area and the cleaning process is repeated until all tasks are completed.

[0092] In some embodiments, the photovoltaic panel cleaning method further comprises the following steps:

[0093] Step S5: After completing the cleaning of all photovoltaic panels, the drone returns to the starting position;

[0094] Step S6: Record the cleaning task data and upload the cleaning task data to the cloud for storage.

[0095] Table 1 shows the main parameter ranges of the quadrotor drone with loosely coupled wake and attitude characteristics of the present invention.

[0096] Table 1

[0097] Components parameter value Duct diameter D 118.24mm Number of guide vanes N 4 Guide vane angle θ 10°～40° Rotor speed RPM 25530 Battery life T 35min

[0098] Although the specific embodiments of the present invention depict various actions or steps in a specific order, this should be understood as requiring such actions or steps to be performed in the specific order shown or in a sequential order, or requiring that all illustrated actions or steps should be performed to obtain the desired results. Under certain circumstances, multitasking and parallel processing may be advantageous. Similarly, although a number of specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of this disclosure. Certain features described in the context of separate embodiments can also be implemented in combination in a single implementation. Conversely, the various features described in the context of a single implementation can also be implemented in multiple implementations individually or in any suitable sub-combination. The above is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or replacements that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered within the scope of protection of the present invention.

[0099] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A quadrotor drone with loosely coupled wake and attitude characteristics, comprising: A fuselage and a plurality of rotor assemblies connected to the fuselage, characterized in that: A flight control system, a visual sensor, and an attitude sensor are provided in the fuselage, and the rotor assembly comprises a rotor (2), a duct (3), and a guide vane (1); The duct (3) surrounds the rotor (2), and the radius of the duct (3) gradually decreases along the airflow direction; the fuselage is connected to an arm (4), and the arm (4) extends into the interior of the duct (3); the guide vane (1) is connected to the arm (4) and extends out of the air outlet of the duct (3); the guide vane (1) includes a starting section, a transition section, and a guide section in sequence along the airflow direction; the starting section and the guide section are planes, the transition section is a curved surface, and the trajectory of the curved surface is a Bezier curve; the flight control system can adjust the angle between the guide section of the guide vane (1) and the ground.

2. The quadrotor UAV with loosely coupled wake and attitude characteristics according to claim 1, characterized in that: The included angle θ between the diversion section and the photovoltaic panel is 10° to 40°, and the optimal included angle between the diversion section and the photovoltaic panel is 20°; the included angle between the photovoltaic panel and the ground is 37°.

3. The quadrotor UAV with loosely coupled wake and attitude characteristics according to claim 2, characterized in that: The fuselage is made of carbon fiber plates; the visual sensor is one or more cameras, and the posture sensor is used to obtain the movement posture of the fuselage; the guide plate (1) is made of TPU soft rubber material 3D printing and has a thickness of 5mm; the diameter of the duct 3 is 118.24mm.

4. A method for designing a guide vane for a quadrotor drone with loosely coupled wake and attitude characteristics based on any one of claims 2-3, characterized in that: The following steps are involved: The point where the starting section and the transition section of the guide plate intersect is set as the first control point, the point where the transition section and the guide section intersect is set as the second control point, and the position of the third control point is adjusted so that when the starting section is perpendicular to the ground, the angle between the guide section and the photovoltaic panel is the optimal angle.

5. The method for designing a guide vane for a quadrotor drone with loosely coupled wake and attitude according to claim 4, characterized in that: The method for obtaining the optimal angle includes the following steps: (1) The angle between the photovoltaic panel and the ground is controlled to be 37°, and dry standard sand with a particle size of 0.25-150 μm is evenly laid on the photovoltaic panel; (2) Hover the drone without guide vanes above the photovoltaic panel, adjust the drone's attitude, and adjust the angle between the drone's rotor airflow and the photovoltaic panel. After cleaning, take an image of the dust remaining on the photovoltaic panel and weigh it to obtain the weight of the dust remaining on the photovoltaic panel. (3) using an image processing method to obtain the dust area ratio of the photovoltaic panel, and obtaining the dust removal rate based on the residual dust weight; (4) The angle between the rotor airflow and the photovoltaic panel that maximizes the dust removal rate and minimizes the dust area is determined as the optimal angle.

6. A photovoltaic panel cleaning method for a quadrotor drone with loosely coupled wake and attitude according to any one of claims 2-3, characterized in that: The following steps are involved: Step S1: Perform a self-check on the UAV and set the mission area position and guide vane inclination angle; Step S2: The UAV drives to the mission area and obtains the positions of multiple photovoltaic panels based on the images captured by the visual sensor; Step S3: Based on the multiple photovoltaic panel positions, an optimal flight path is generated using a path planning strategy, where the optimal flight path passes through all photovoltaic panel positions; Step S4: The drone cleans each photovoltaic panel along the optimal flight path. During cleaning, the guide vane is adjusted using a PID control algorithm based on the data from the visual sensor and the attitude sensor so that the angle between the guide section of the guide vane and the photovoltaic panel is the optimal angle.

7. The photovoltaic panel cleaning method of a quadrotor drone with loosely coupled wake and attitude according to claim 6, characterized in that: Step S3 specifically includes: Step S3-1, obtaining the position and attitude information of the UAV by the attitude sensor; Step S3-2: Input the multiple photovoltaic panel positions and the position and attitude information of the drone into a path planning algorithm to generate an optimal flight path passing through all photovoltaic panel positions.

8. The photovoltaic panel cleaning method of a quadrotor drone with loosely coupled wake and attitude according to claim 7, characterized in that: The specific steps of cleaning in step S4 include: (1) Arriving above the photovoltaic panel, the visual sensor and attitude sensor obtain the position, tilt angle and rotation direction of the aircraft; (2) calculating the deviation between the angle between the guide section of the current guide plate and the photovoltaic panel and the optimal angle based on the current photovoltaic panel position and the position, tilt angle and rotation direction of the fuselage; (3) Based on the deviation, a PID control algorithm is used to calculate the corresponding control signal in real time according to the preset proportional, integral and differential parameters, and the deflection angle of the guide vane is adjusted in real time.

9. The photovoltaic panel cleaning method of a quadrotor drone with loosely coupled wake and attitude according to claim 8, characterized in that: The following steps are also included Step S5: After completing the cleaning of all photovoltaic panels, the drone returns to the starting position; Step S6: Record the cleaning task data and upload the cleaning task data to the cloud for storage.

Images