Waterless photovoltaic cleaning unmanned aerial vehicle based on dust retention mechanical model

Abstract

The invention relates to an anhydrous photovoltaic cleaning unmanned aerial vehicle based on a dust retention mechanical model, and belongs to photovoltaic panel cleaning. A speed-increasing and flow-increasing duct plasticizes high-speed and downward airflow generated by propellers driven by brushless motors to generate high-speed airflow; based on the flow-increasing and speed-increasing duct, the accumulated dust mechanical model and the removal condition of the adhered particles, the flow speed of the outlet airflow is effectively increased, the accelerated high-speed airflow has high flow speed and cleaning effect, and accumulated dust and dust on the surface of the photovoltaic panel can be effectively removed; on the other hand, aiming at the unmanned aerial vehicle vision and path planning problem, an edge straight line detection image processing technology is adopted, a cleaning area is positioned, in addition, four sets of notches are designed in the bottom side of the speed and flow increasing duct, and the stability of the unmanned aerial vehicle in high-load operation is ensured; the carbon plate connecting assembly is made of high-strength and light-weight carbon fiber materials, large stress can be borne, the overall weight is reduced, and the flight efficiency and the cruising ability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic panel cleaning, and in particular to a waterless photovoltaic cleaning drone based on a dust accumulation mechanics model, and in particular to a drone based on a dust accumulation mechanics model and a method for waterless photovoltaic cleaning. Background Art

[0002] my country's western region is rich in solar energy resources. my country's photovoltaic industry has made significant progress from distributed to centralized and then to large-scale photovoltaic projects. By the end of the year, my country's total photovoltaic installed capacity had crossed the important threshold of 600 million kilowatts, reaching 609.49 million kilowatts, achieving three major breakthroughs in succession, surpassing hydropower to become the second largest installed power source of the year, accounting for 21% of the country's total installed power capacity. The annual photovoltaic power generation reached 294 billion kilowatt-hours, an increase of 17.17% year-on-year, accounting for 3.3% of my country's total power generation, and is rapidly moving towards a dominant energy status.

[0003] Photovoltaic modules are exposed to the air for a long time. Due to dust coverage, the effective irradiation area of ​​solar radiation is reduced, and the transmittance of silicon crystals on the surface of the modules is affected, reducing the efficiency of photovoltaic power generation. When exposed to sunlight for a long time, the temperature of the covered parts will rise significantly because the heat cannot be dissipated in time, and then burnt hot spots will form on the surface of the modules, causing large-scale damage to the photovoltaic modules.

[0004] At present, the cleaning methods of photovoltaic panels mainly include cleaning vehicles and manual cleaning. The cleaning vehicle uses a high-pressure water gun for cleaning, which generally requires two employees to operate. The range can reach 30 meters and effectively covers the cleaning area. However, this method is costly, and most of my country's large-scale photovoltaic power stations are concentrated in the northwest region, where water resources are relatively scarce. Using high-pressure water guns for cleaning will lead to a waste of water resources. Manual cleaning includes two categories: dry cleaning and water washing. Dry cleaning mainly uses a long-handled velvet mop with a special dust detergent, and uses the principle of electrostatic adsorption to absorb dust and sand, thereby enhancing the dust absorption and decontamination ability of cleaning tools, thereby effectively reducing the flying of dust and sand during cleaning. However, this method may cause more surface residues, and uneven force on the components may cause deformation and cracking problems. The water washing method uses equipment with water storage function, such as a water storage vehicle, to clean the photovoltaic panel components with a manually operated nozzle, and the cleaning effect is better. However, after water washing, traces of sewage may remain on the surface of the photovoltaic panel, affecting the light transmission performance of the glass, and the water resource consumption is large.

[0005] In order to solve the problem of cleaning dust on photovoltaic panels, the prior art provides the following solutions: Chinese patent application CN115889271A proposes a solution of using drones for inspection, launching photovoltaic cleaning drones, and cleaning photovoltaic panels. However, the process of launching cleaning drones for cleaning and transporting them after cleaning is relatively cumbersome, with high requirements for the reliability of the launch operation, low efficiency, high commercialization difficulty, and difficulty in actual use.

[0006] Chinese patent application CN117208202A proposes a photovoltaic panel cleaning drone equipped with a water tank and water pump to spray water on photovoltaic panels to clean them. However, photovoltaic power plants are mostly located in the northwest region, where water resources are scarce, and the main pollutants on the panels are mostly dust. If a water-based cleaning method is used, scale and dirt will form on the panels, which may cause secondary shading of the photovoltaic panels. Summary of the invention

[0007] In view of the above problems, the present invention provides a waterless photovoltaic cleaning UAV based on the dust accumulation mechanics model. On the one hand, the UAV of the present invention is designed with a plasticized and flow-increasing duct, which effectively increases the outlet airflow velocity based on the flow-increasing and speed-increasing duct and the dust accumulation mechanics model and the removal conditions of adhered particles; on the other hand, the present invention addresses the UAV vision and path planning problems, and uses image processing technology for edge straight line detection to locate the cleaning area.

[0008] The present invention provides a water-free photovoltaic cleaning UAV based on a dust accumulation mechanics model, comprising: a speed-increasing and flow-increasing duct 1, a carbon plate connecting component and a UAV.

[0009] The speed increasing and flow increasing duct 1 is connected to the UAV via a carbon plate connecting assembly;

[0010] The speed increasing and flow increasing duct is used to solve the problem of too low wind speed and scattered flow speed generated by the UAV rotor;

[0011] Preferably, the UAV is a quad-rotor UAV;

[0012] Preferably, the speed increasing and flow increasing duct 1 comprises a support arm assembly, a cross beam assembly and a skin 1-2;

[0013] The support arm assembly is connected to the cross beam assembly to form a duct frame 1-1, and a cavity is formed in the duct frame 1-1; the skin 1-2 is connected to the support arm assembly and the cross beam assembly respectively; the UAV is arranged in the cavity;

[0014] Furthermore, the skin 1-2 is a heat shrinkable film material used in the field of model aircraft;

[0015] The structure of the speed increasing and flow increasing duct 1 is an axisymmetric and center symmetric structure;

[0016] Furthermore, the duct skeleton 1-1 defines the outline of the speed-increasing and flow-increasing duct 1;

[0017] The cross section of the duct skeleton 1-1 gradually decreases from the inlet to the outlet of the speed-increasing and flow-increasing duct 1, and the cross section is perpendicular to the longitudinal center axis of the speed-increasing and flow-increasing duct 1;

[0018] The skin 1-2 matches the shape of the duct frame 1-1 and tightly covers and is fixed on the duct frame 1-1.

[0019] Furthermore, the support arm assembly includes at least two support arms 1-3; the crossbeam assembly includes at least two crossbeams 1-4;

[0020] The at least two cross beams 1-4 are vertically arranged on the cross section along the longitudinal center axis of the speed increasing and flow increasing duct 1 to form a closed structure;

[0021] The enclosed area of ​​the at least two cross beams 1-4 gradually decreases in the direction from the inlet to the outlet of the speed increasing and flow increasing duct;

[0022] The cross beams 1-4 are arranged sequentially along the longitudinal center axis of the speed-increasing and flow-increasing duct so that the spacing between adjacent cross beams is the same; and wherein the at least two support arms 1-3 extend along the contour of the duct skeleton in a substantially longitudinal direction and are engaged with the cross beams 1-4, and the at least two cross beams and the at least two support arms together form a network structure, constituting a structurally stable duct skeleton 1-1.

[0023] Exemplarily, the support arm assembly is configured so that adjacent support arms have the same spacing.

[0024] Exemplarily, the support arms are arranged to have a smaller spacing at the corners to have a greater density.

[0025] Preferably, the flow-increasing and speed-increasing duct 1 is manufactured using a 3D printing process, and the entire assembly adopts a skin-frame structure, which greatly reduces weight and alleviates the flight load of the UAV.

[0026] Furthermore, the skin 1-2 and the duct frame 1-1 are each provided with at least one slot at the airflow outlet, the duct frame 1-1 has a frame slot 1-5, and the skin 1-2 may have a skin slot; the slot is used to connect with the UAV, and the shape of the slot may be formed into a shape matching the corresponding assembly part of the UAV as required.

[0027] Furthermore, the positions of the skeleton slots 1-5 and the skin slots are evenly arranged along the outlet edges of the duct skeleton 1-1 and the skin 1-2 respectively and the numbers are the same, and after the duct skeleton 1-1 and the skin 1-2 are assembled, the positions of the skeleton slots 1-5 and the skin slots correspond to each other.

[0028] Optionally, the frame notch 1-5 is formed on the support arm 1-3 of the duct frame 1 at the outlet end of the duct frame 1-1, along the longitudinal direction of the support arm 1-3, such as Figure 2 As shown, the structural strength of the duct frame is ensured to avoid affecting the structural strength of the crossbeam assembly of the duct frame 1.

[0029] In one embodiment, the UAV speed increasing and flow increasing duct includes a skeleton lip 1-6; the skeleton lip 1-6 can be integrally printed when the duct skeleton 1-1 is 3D printed;

[0030] The skin is made into a structure suitable for the lip of the frame. When the skin 2 is covered on the duct frame 1, it is covered along the lip and structure of the duct frame 1. The structural design of the lip can be subjected to mechanical strength analysis;

[0031] Further, the frame lip 1-6 includes two horizontal beams 1-4 arranged at the inlet end of the duct frame 1, and a group of short vertical beams 1-61 between the two horizontal beams 1-4; the number of the short vertical beams 1-61 of the frame lip 1-6 can be more than the vertical beams 1-3 of the duct frame 1-1, so as to provide more reliable support and structural strength at the frame lip 1-6 when the increased incoming airflow brings about a greater impact force;

[0032] In an optional embodiment, the frame lip 1-6 is formed in an outwardly expanding shape. That is, the frame lip 1-6 is slightly offset outwardly at an angle relative to the central axis of the duct. The expansion angle of the frame lip 1-6 can be set to be generally 0 to 25 degrees outwardly; the frame lip 1-6 is designed to directly affect the intake volume of the duct by acting on the airflow pressure of the duct lip;

[0033] Optionally, the lip can be set so that the skeleton lips 1-6 are deflected outward by about 20 degrees to achieve optimal values ​​of aerodynamic efficiency, air intake volume, stall characteristics, and thrust characteristics, and the air intake volume reaches a maximum value.

[0034] Optionally, the structure of the skeleton lip 1-6 is a streamlined symmetrical airfoil structure to fully comply with the principles of fluid mechanics. The streamlined design allows the airflow to flow smoothly over the airfoil surface of the lip, while also increasing lift. The skeleton lip 1-6 of the streamlined symmetrical airfoil structure is slightly thicker than other parts of the duct skeleton 1-1, and is slightly pointed at the leading edge. From a cross-section, the skeleton lip 1-6 is a thinner willow leaf shape, forming a smooth overall shape. The curvature of the curve of the upper airfoil surface of the skeleton lip 1-6 (i.e., the inner side facing the inside of the duct) is slightly larger than the curvature of the curve of the opposite lower airfoil surface (i.e., the outer side facing the outside of the duct), so as to form a low pressure inside the duct lip and bring about a better airflow effect.

[0035] Preferably, the drone includes a motor assembly, an electric regulator, a propeller assembly, a flight control system 9, a power supply, a receiver 4 and a GPS module 10;

[0036] The receiver 4, GPS module 10 and flight control system are arranged on a frame;

[0037] The propeller assembly includes a connecting rod assembly, a rotor mounting platform assembly and a propeller blade assembly;

[0038] The frame is connected to the propeller blade assembly via a rotor mounting platform assembly and a connecting rod assembly;

[0039] Furthermore, the frame is made of carbon fiber laminate material;

[0040] The connecting rod assembly is made of a hollow carbon tube and is connected to the frame by bolts, which reduces the weight while ensuring the strength and rigidity of the UAV frame structure;

[0041] The electric speed controller can adjust the motor speed in real time through the signal transmitted by the flight control system to achieve the control of the attitude and position of the UAV;

[0042] The propeller assembly includes a plurality of propellers; each propeller is a two-blade propeller made of carbon fiber material, which has low density and high strength, is not prone to vibration under high-speed rotation, and provides stable rotor lift. At the same time, the two-blade propeller has higher efficiency than the multi-blade propeller;

[0043] The flight control system is the open source flight control Pixhawk 4, which comes with multiple sensors, such as a 3-axis 16-bit gyroscope, a 3-axis 14-bit accelerometer, a magnetometer and a barometer. The open source flight control Pixhawk 4 autopilot can control the flight of the drone without external sensors. At the same time, an externally connected GPS module allows the drone to use the signal of the GPS module for positioning, providing the specific location information of the drone and automatically completing the operation.

[0044] The frame is arranged at the center of the speed increasing and flow increasing component 1;

[0045] Further, the connecting rod assembly includes connecting rod 1 5, connecting rod 2, connecting rod 3 and connecting rod 4; the connecting rod 1 5, connecting rod 2, connecting rod 3 and connecting rod 4 are respectively connected to the four diagonals of the frame;

[0046] The propeller blade assembly includes propeller blade one, propeller blade two, propeller blade three and propeller blade four;

[0047] The rotor mounting platform assembly includes: rotor mounting platform one, rotor mounting platform two, rotor mounting platform three and rotor mounting platform four;

[0048] The motor assembly includes four motors, which are divided into two pairs. The motors in each pair rotate in opposite directions to offset the torque generated by the rotation of the motors, so that the drone will not rotate on its own.

[0049] Further, the motor assembly includes motor 1 7, motor 2, motor 3 and motor 4;

[0050] The propeller blade 1 2 is respectively connected to the rotor mounting platform 1 6, the motor 1 7 and the connecting rod 1;

[0051] Furthermore, the connection method of the connecting rod 2, the connecting rod 3 and the connecting rod 4 is the same as that of the connecting rod 1;

[0052] Exemplarily, the motor 1, motor 2, motor 3 and motor 4 are all three-phase AC brushless motors;

[0053] Furthermore, the flight control system is placed on the upper surface of the frame through a rubber shock-absorbing gasket;

[0054] The motor 1 comprises an output shaft and a motor body; the output shaft is connected to a propeller blade;

[0055] The flight control system transmits electrical signals to the electric regulator, and the electric regulator converts the electrical signals into three-phase AC electrical signals and outputs them to motors one, two, three and four, driving propeller blades one, two, three and four to rotate.

[0056] Exemplarily, the propeller 1 is screwed onto the rotor of the motor 1, and the rotation of the motor 1 drives the propeller 1 to rotate.

[0057] Preferably, the carbon plate connection assembly includes a carbon plate connection piece 1, a carbon plate connection piece 2 3, a carbon plate connection piece 3 and a carbon plate connection piece 4;

[0058] The carbon plate connecting member 1 includes a carbon plate 1 and a carbon plate 2; one end of the carbon plate 1 and the carbon plate 2 are connected to the connecting rod 1 through a bolt 1 8;

[0059] Furthermore, the other ends of the carbon plate 1 and the carbon plate 2 are connected to a notch of the flow and speed increasing duct;

[0060] The carbon plate connecting member 2, the carbon plate connecting member 3 and the carbon plate connecting member 4 are connected in the same manner as the carbon plate connecting member 1;

[0061] Exemplarily, the carbon plate connector 1, the carbon plate connector 2, the carbon plate connector 3 and the carbon plate connector 4 are all made of carbon fiber materials;

[0062] The carbon plate connector 1, carbon plate connector 2, carbon plate connector 3 and carbon plate connector 4 designed in the present invention are all made of high-strength, light-weight carbon fiber materials, which can not only withstand greater stress, but also significantly reduce the overall weight of the drone, thereby improving flight efficiency and endurance.

[0063] The present invention designs an speed increasing and flow increasing component with an axially symmetrical and centrally symmetrical structure, and four groups of notches are designed on the bottom side thereof, thereby ensuring that the speed increasing and flow increasing component, the UAV, and the carbon plate connecting component can still maintain a stable connection during high-load operation; in addition, the design of the four groups of notches enables the four groups of carbon plate connecting parts to be easily inserted; the other ends of the four groups of carbon plate connecting parts are fixedly connected to the UAV rotor mounting platform by bolts.

[0064] Another object of the present invention is to provide a method for performing waterless photovoltaic cleaning using a waterless photovoltaic cleaning drone based on a dust accumulation mechanics model, comprising:

[0065] The water-free photovoltaic cleaning drone flies to the air above the photovoltaic panel to be cleaned, and is controlled by the flight control system (9) to hover stably;

[0066] Obtaining conditions for removing particles adhering to a photovoltaic panel to be cleaned;

[0067] Based on the removal condition of the adhered particles, a minimum wind speed for removing the adhered particles is obtained, and the minimum wind speed is input into the flight control system 9 to obtain a three-phase alternating current signal;

[0068] The motor assembly receives a three-phase alternating current signal, driving the propeller blade assembly to rotate and generate a corresponding airflow; the corresponding airflow passes through the speed increasing and flow increasing duct 1 to generate a high-speed airflow, and the high-speed airflow is used to clean the photovoltaic panel to be cleaned.

[0069] Furthermore, the water-free photovoltaic cleaning drone is controlled to take off stably and reach a preset height;

[0070] After reaching the predetermined height, the waterless photovoltaic cleaning drone navigates along the preset path, adjusts the flight direction and altitude, and flies over the photovoltaic panel to be cleaned;

[0071] After reaching the target position, the drone hovers, and the flight control system 9 ensures its stability;

[0072] Obtain the conditions for removing adhered particles on the photovoltaic panel to be cleaned; obtain the minimum wind speed for removing adhered particles based on the conditions for removing adhered particles and the mechanical model of dust accumulation, input the minimum wind speed into the flight control system 9, obtain an electrical signal and transmit it to the electric regulator, the electric regulator converts the electrical signal into a three-phase AC signal and outputs it to motor 1 7, motor 2, motor 3 and motor 4; drive propeller blade 1 2, propeller blade 2, propeller blade 3 and propeller blade 4 to rotate to generate corresponding airflow, the corresponding airflow passes through the speed increasing and flow increasing duct 1 to generate a high-speed airflow, and the photovoltaic panel to be cleaned is cleaned with the high-speed airflow.

[0073] Furthermore, the design of the UAV speed-increasing and flow-increasing duct is based on the incompressible fluid continuity formula, which accelerates the airflow and generates a high-speed airflow by shrinking the cross-sectional area of ​​the duct from the inlet to the outlet. The expression of the incompressible fluid continuity is:

[0074] ρV1A1=ρV2A2

[0075]

[0076] Where A1 is the inlet area and A2 is the outlet area. The cross section of the duct perpendicular to its longitudinal central axis contracts smoothly from the inlet to the outlet. For example, in an illustrative example, the inlet area A1 of the duct designed by the above formula is 0.57m 2 , the outlet area A2 of the duct is 0.225m 2 , the inlet and outlet contraction ratio is 0.395. In this example, the air velocity at the outlet after acceleration is about 2.5 times the velocity at the blade of the drone, which effectively increases the wind speed generated by the drone during flight. ρ is the air density of the flight environment, V1 is the air inlet air velocity, and V2 is the air outlet air velocity.

[0077] The expression of the deposition mechanics model is:

[0078] F ad =F e +F vdw +G y +F buoyancy

[0079] Among them, F ad is the main adhesion force of dust particles perpendicular to the solar panel surface, F e is the electrostatic force, F vdw is the van der Waals force, G y is the gravity component, F buoyancy is the buoyancy of microparticles in the air.

[0080] Furthermore, the rotation of propeller blades one, two, three and four generates corresponding air flow velocities u a The expression is:

[0081]

[0082] Among them, Cv is the dimensionless speed coefficient, N is the propeller speed (unit RPM, revolutions per minute), Dp is the propeller diameter, and ρ is the air density of the flight environment, which is related to the flight altitude.

[0083] The removal condition of the adhered particles is expressed as:

[0084]

[0085] Where k0 is the static friction coefficient, d p is the diameter of the dust particle, F n is the supporting force, and p0 is the adhesion force of the adhesion particles.

[0086] Preferably, the specific steps of flying over the photovoltaic panel to be cleaned include:

[0087] Acquire RGB images of photovoltaic panels to be cleaned based on drones;

[0088] Gaussian filtering is used to preprocess the RGB image of the photovoltaic panel to be cleaned to remove image noise and obtain a preprocessed RGB image;

[0089] Convert the preprocessed RGB image into an HSV image;

[0090] Determine the color threshold of photovoltaic panels;

[0091] Cutting the HSV image based on the color threshold and then performing dilation and corrosion processing to obtain a processed image;

[0092] The part of the processed image that matches the shape and size of the photovoltaic panel is retained, and the contours that do not match the area and shape are removed. Based on the Sobel filter, the edge area of ​​the photovoltaic panel to be cleaned is obtained;

[0093] The edge area of ​​the photovoltaic panel to be cleaned is represented in the RGB image of the photovoltaic panel to be cleaned, and edge detection is performed to obtain the cleaning area of ​​the photovoltaic panel to be cleaned. The drone flies above the photovoltaic panel to be cleaned according to the cleaning area of ​​the photovoltaic panel to be cleaned.

[0094] It can be understood that the flight control system 9 ensures its stability to prevent the drone from deviating from the target due to airflow disturbance or wind influence;

[0095] Preferably, the preset path navigation is a remote control instruction of an operator or a flight path pre-planned by a ground station;

[0096] Preferably, the specific steps of controlling the water-free photovoltaic cleaning drone to take off stably and reach a preset height in step 1 include:

[0097] Controlling the remote controller to send an operation instruction to the water-free photovoltaic cleaning drone; the operation instruction is transmitted to the drone via radio waves;

[0098] The drone transmits the operation instruction to the flight control system 9;

[0099] After receiving the operation command, the flight control system 9 performs a status check; the status check includes the status of the drone sensor, battery power, motor and electric regulator;

[0100] After the status check is completed, the flight control system 9 sends a low-frequency pulse signal to the ESC to start the corresponding motor, driving the corresponding propeller to rotate at a low speed;

[0101] The flight control system controls the four motors to accelerate synchronously and at the same time controls the attitude of the drone, allowing the drone to leave the ground, take off smoothly, and reach a predetermined height.

[0102] The take-off process of the drone in the present invention includes the flight control gradually increasing the motor speed, driving the propeller to rotate, and generating sufficient thrust to make the drone take off smoothly. After the drone is smoothly lifted off, the flight control automatically adjusts the flight direction and altitude according to the pre-set path navigation, flies to the sky above the photovoltaic panel to be cleaned, and after reaching the target position, the drone hovers above the photovoltaic panel. The flight control ensures that it hovers stably to avoid deviation from the target due to airflow disturbance or wind influence. The motor drives the propeller to generate high-speed, downward airflow. When the airflow passes through the speed-increasing and flow-increasing components, its flow rate is further accelerated to form a high-speed airflow. The high-speed airflow after the speed increase has a higher flow rate and cleaning effect, and can effectively remove dust and dirt on the surface of the photovoltaic panel.

[0103] Compared with the prior art, the present invention has at least the following beneficial effects:

[0104] (1) The speed increasing and flow increasing duct of the present invention plasticizes the high-speed, downward airflow generated by the propeller driven by the brushless motor to generate a high-speed airflow. The high-speed airflow after the speed increase has a high flow rate and a cleaning effect, and can effectively remove dust and dirt on the surface of the photovoltaic panel;

[0105] (2) Four sets of notches are designed on the bottom side of the speed increasing and flow increasing duct of the present invention to ensure that the UAV and the carbon plate connection assembly can still maintain a stable connection during high-load operation;

[0106] (3) The carbon plate connection assembly of the present invention uses high-strength, light-weight carbon fiber materials, which can not only withstand greater stress, but also significantly reduce the overall weight of the drone, thereby improving flight efficiency and endurance;

[0107] (4) The flow-increasing and speed-increasing duct frame of the present invention adopts a 3D printing process, and the entire assembly adopts a skin-frame structure, which can greatly reduce the weight and reduce the flight load of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0108] The drawings are only for the purpose of illustrating particular embodiments and are not to be construed as limiting the invention.

[0109] Figure 1 Schematic diagram of the structure of a water-free photovoltaic cleaning drone based on a dust accumulation mechanics model in an embodiment of the present invention;

[0110] Figure 2 It is a schematic diagram of a physical picture of a water-free photovoltaic cleaning drone based on a dust accumulation mechanics model in an embodiment of the present invention;

[0111] Figure 3 It is a schematic diagram of the structure of the speed-increasing and flow-increasing duct in the water-free photovoltaic cleaning drone based on the dust accumulation mechanics model in an embodiment of the present invention.

[0112] Reference numerals:

[0113] 1-speed increase and flow increase duct, 2-propeller blade 2, 3-carbon plate connector 1, 4-receiver, 5-connecting rod 1, 6-rotor mounting platform, 7-motor 1, 8-bolt 1, 9-flight control system, 10-GPS, 1-1-duct frame, 1-2-skin, 1-3-support arm, 1-4-cross beam, 1-5-frame notch, 1-6-frame lip, 1-61-short vertical beam DETAILED DESCRIPTION

[0114] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with 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, and therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0115] A specific embodiment of the present invention, as Figure 1-3 , discloses a UAV based on a dust accumulation mechanics model and a method for waterless photovoltaic cleaning,

[0116] 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, and the specific implementation steps are as follows:

[0117] The present invention provides a water-free photovoltaic cleaning UAV based on a dust accumulation mechanics model, comprising: a speed-increasing and flow-increasing duct 1, a carbon plate connecting component and a UAV.

[0118] The speed increasing and flow increasing duct 1 is connected to the UAV via a carbon plate connecting assembly;

[0119] The speed increasing and flow increasing duct is used to solve the problem of too low wind speed and scattered flow speed generated by the UAV rotor;

[0120] Preferably, the UAV is a quad-rotor UAV;

[0121] Preferably, the speed increasing and flow increasing duct 1 comprises a support arm assembly, a cross beam assembly and a skin 1-2;

[0122] The support arm assembly is connected to the cross beam assembly to form a duct frame 1-1, and a cavity is formed in the duct frame 1-1; the skin 1-2 is connected to the support arm assembly and the cross beam assembly respectively; the UAV is arranged in the cavity;

[0123] Furthermore, the skin 1-2 is a heat shrinkable film material used in the field of model aircraft;

[0124] The structure of the speed increasing and flow increasing duct 1 is an axisymmetric and center symmetric structure;

[0125] Furthermore, the duct skeleton 1-1 defines the outline of the speed-increasing and flow-increasing duct 1;

[0126] The cross section of the duct skeleton 1-1 gradually decreases from the inlet to the outlet of the speed-increasing and flow-increasing duct 1, and the cross section is perpendicular to the longitudinal center axis of the speed-increasing and flow-increasing duct 1;

[0127] The skin 1-2 matches the shape of the duct frame 1-1 and tightly covers and is fixed on the duct frame 1-1.

[0128] Furthermore, the support arm assembly includes at least two support arms 1-3; the crossbeam assembly includes at least two crossbeams 1-4;

[0129] The at least two cross beams 1-4 are vertically arranged on the cross section along the longitudinal center axis of the speed increasing and flow increasing duct 1 to form a closed structure;

[0130] The enclosed area of ​​the at least two cross beams 1-4 gradually decreases in the direction from the inlet to the outlet of the speed increasing and flow increasing duct;

[0131] The cross beams 1-4 are arranged sequentially along the longitudinal center axis of the speed-increasing and flow-increasing duct so that the spacing between adjacent cross beams is the same; and wherein the at least two support arms 1-3 extend along the contour of the duct skeleton in a substantially longitudinal direction and are engaged with the cross beams 1-4, and the at least two cross beams and the at least two support arms together form a network structure, constituting a structurally stable duct skeleton 1-1.

[0132] Exemplarily, the support arm assembly is configured so that adjacent support arms have the same spacing.

[0133] Exemplarily, the support arms are arranged to have a smaller spacing at the corners to have a greater density.

[0134] Preferably, the flow-increasing and speed-increasing duct 1 is manufactured using a 3D printing process, and the entire assembly adopts a skin-frame structure, which greatly reduces weight and alleviates the flight load of the UAV.

[0135] Furthermore, the skin 1-2 and the duct frame 1-1 are each provided with at least one slot at the airflow outlet, the duct frame 1-1 has a frame slot 1-5, and the skin 1-2 may have a skin slot; the slot is used to connect with the UAV, and the shape of the slot may be formed into a shape matching the corresponding assembly part of the UAV as required.

[0136] Furthermore, the positions of the frame slots 1-5 and the skin slots are evenly arranged along the outlet edges of the duct frame 1-1 and the skin 1-2 respectively and the number is the same, and after the duct frame 1-1 and the skin 1-2 are assembled, the positions of the frame slots 30 and the skin slots correspond to each other.

[0137] Optionally, the frame notch 1-5 is formed on the support arm 1-3 of the duct frame 1 at the outlet end of the duct frame 1-1, along the longitudinal direction of the support arm 1-3, such as Figure 2 As shown, the structural strength of the duct frame is ensured to avoid affecting the structural strength of the crossbeam assembly of the duct frame 1.

[0138] In one embodiment, the UAV speed increasing and flow increasing duct includes a skeleton lip 1-6; the skeleton lip 1-6 can be integrally printed when the duct skeleton 1-1 is 3D printed;

[0139] The skin is made into a structure suitable for the lip of the frame. When the skin 2 is covered on the duct frame 1, it is covered along the lip and structure of the duct frame 1. The structural design of the lip can be subjected to mechanical strength analysis;

[0140] Further, the frame lip 1-6 includes two horizontal beams 1-4 arranged at the inlet end of the duct frame 1, and a group of short vertical beams 1-61 between the two horizontal beams 1-4; the number of the short vertical beams 1-61 of the frame lip 1-6 can be more than the vertical beams 1-3 of the duct frame 1-1, so as to provide more reliable support and structural strength at the frame lip 1-6 when the increased incoming airflow brings about a greater impact force;

[0141] In an optional embodiment, the frame lip 1-6 is formed in an outwardly expanding shape. That is, the frame lip 1-6 is slightly offset outwardly at an angle relative to the central axis of the duct. The expansion angle of the frame lip 1-6 can be set to be generally 0 to 25 degrees outwardly; the frame lip 1-6 is designed to directly affect the intake volume of the duct by acting on the airflow pressure of the duct lip;

[0142] Optionally, the lip can be set so that the skeleton lips 1-6 are deflected outward by about 20 degrees to achieve optimal values ​​of aerodynamic efficiency, air intake volume, stall characteristics, and thrust characteristics, and the air intake volume reaches a maximum value.

[0143] Optionally, the structure of the skeleton lip 1-6 is a streamlined symmetrical airfoil structure to fully comply with the principles of fluid mechanics. The streamlined design allows the airflow to flow smoothly over the airfoil surface of the lip, while also increasing lift. The skeleton lip 1-6 of the streamlined symmetrical airfoil structure is slightly thicker than other parts of the duct skeleton 1-1, and is slightly pointed at the leading edge. From a cross-section, the skeleton lip 1-6 is a thinner willow leaf shape, forming a smooth overall shape. The curvature of the curve of the upper airfoil surface of the skeleton lip 1-6 (i.e., the inner side facing the inside of the duct) is slightly larger than the curvature of the curve of the opposite lower airfoil surface (i.e., the outer side facing the outside of the duct), so as to form a low pressure inside the duct lip and bring about a better airflow effect.

[0144] Preferably, the drone includes a motor assembly, an electric regulator, a propeller assembly, a flight control system 9, a power supply, a receiver 4 and a GPS module 10;

[0145] The receiver 4, GPS module 10 and flight control system are arranged on a frame;

[0146] The propeller assembly includes a connecting rod assembly, a rotor mounting platform assembly and a propeller blade assembly;

[0147] The frame is connected to the propeller blade assembly via a rotor mounting platform assembly and a connecting rod assembly;

[0148] Furthermore, the frame is made of carbon fiber laminate material;

[0149] The connecting rod assembly is made of a hollow carbon tube and is connected to the frame by bolts, which reduces the weight while ensuring the strength and rigidity of the UAV frame structure;

[0150] The electric speed controller can adjust the motor speed in real time through the signal transmitted by the flight control system to achieve the control of the attitude and position of the UAV;

[0151] The propeller assembly includes a plurality of propellers; each propeller is a two-blade propeller made of carbon fiber material, which has low density and high strength, is not prone to vibration under high-speed rotation, and provides stable rotor lift. At the same time, the two-blade propeller has higher efficiency than the multi-blade propeller;

[0152] The flight control system is the open source flight control Pixhawk 4, which comes with multiple sensors, such as a 3-axis 16-bit gyroscope, a 3-axis 14-bit accelerometer, a magnetometer and a barometer. The open source flight control Pixhawk 4 autopilot can control the flight of the drone without external sensors. At the same time, an externally connected GPS module allows the drone to use the signal of the GPS module for positioning, providing the specific location information of the drone and automatically completing the operation.

[0153] The frame is arranged at the center of the speed increasing and flow increasing component 1;

[0154] Further, the connecting rod assembly includes connecting rod 1 5, connecting rod 2, connecting rod 3 and connecting rod 4; the connecting rod 1 5, connecting rod 2, connecting rod 3 and connecting rod 4 are respectively connected to the four diagonals of the frame;

[0155] The propeller blade assembly includes propeller blade one, propeller blade two, propeller blade three and propeller blade four;

[0156] The rotor mounting platform assembly includes: rotor mounting platform one, rotor mounting platform two, rotor mounting platform three and rotor mounting platform four;

[0157] The motor assembly includes four motors, which are divided into two pairs. The motors in each pair rotate in opposite directions to offset the torque generated by the rotation of the motors, so that the drone will not rotate on its own.

[0158] Further, the motor assembly includes motor 1 7, motor 2, motor 3 and motor 4;

[0159] The propeller blade 1 2 is respectively connected to the rotor mounting platform 1 6, the motor 1 7 and the connecting rod 1;

[0160] Furthermore, the connection method of the connecting rod 2, the connecting rod 3 and the connecting rod 4 is the same as that of the connecting rod 1;

[0161] Exemplarily, the motor 1, motor 2, motor 3 and motor 4 are all three-phase AC brushless motors;

[0162] Furthermore, the flight control system is placed on the upper surface of the frame through a rubber shock-absorbing gasket;

[0163] The motor 1 comprises an output shaft and a motor body; the output shaft is connected to a propeller blade;

[0164] The flight control system transmits electrical signals to the electric regulator, and the electric regulator converts the electrical signals into three-phase AC electrical signals and outputs them to motors one, two, three and four, driving propeller blades one, two, three and four to rotate.

[0165] Exemplarily, the propeller 1 is screwed onto the rotor of the motor 1, and the rotation of the motor 1 drives the propeller 1 to rotate.

[0166] Preferably, the carbon plate connection assembly includes a carbon plate connection piece 1, a carbon plate connection piece 2 3, a carbon plate connection piece 3 and a carbon plate connection piece 4;

[0167] The carbon plate connecting member 1 includes a carbon plate 1 and a carbon plate 2; one end of the carbon plate 1 and the carbon plate 2 are connected to the connecting rod 1 through a bolt 1 8;

[0168] Furthermore, the other ends of the carbon plate 1 and the carbon plate 2 are connected to a notch of the flow and speed increasing duct;

[0169] The carbon plate connecting member 2, the carbon plate connecting member 3 and the carbon plate connecting member 4 are connected in the same manner as the carbon plate connecting member 1;

[0170] Exemplarily, the carbon plate connector 1, the carbon plate connector 2, the carbon plate connector 3 and the carbon plate connector 4 are all made of carbon fiber materials;

[0171] The carbon plate connector 1, carbon plate connector 2, carbon plate connector 3 and carbon plate connector 4 designed in the present invention are all made of high-strength, light-weight carbon fiber materials, which can not only withstand greater stress, but also significantly reduce the overall weight of the drone, thereby improving flight efficiency and endurance.

[0172] The present invention designs an speed increasing and flow increasing component with an axially symmetrical and centrally symmetrical structure, and four groups of notches are designed on the bottom side thereof, thereby ensuring that the speed increasing and flow increasing component, the UAV, and the carbon plate connecting component can still maintain a stable connection during high-load operation; in addition, the design of the four groups of notches enables the four groups of carbon plate connecting parts to be easily inserted; the other ends of the four groups of carbon plate connecting parts are fixedly connected to the UAV rotor mounting platform by bolts.

[0173] Another object of the present invention is to provide a method for performing waterless photovoltaic cleaning using a waterless photovoltaic cleaning drone based on a dust accumulation mechanics model, comprising:

[0174] The water-free photovoltaic cleaning drone flies to the air above the photovoltaic panel to be cleaned, and is controlled by the flight control system (9) to hover stably;

[0175] Obtaining conditions for removing particles adhering to a photovoltaic panel to be cleaned;

[0176] Based on the removal condition of the adhered particles, a minimum wind speed for removing the adhered particles is obtained, and the minimum wind speed is input into the flight control system 9 to obtain a three-phase alternating current signal;

[0177] The motor assembly receives a three-phase alternating current signal, driving the propeller blade assembly to rotate and generate a corresponding airflow; the corresponding airflow passes through the speed increasing and flow increasing duct 1 to generate a high-speed airflow, and the high-speed airflow is used to clean the photovoltaic panel to be cleaned.

[0178] Furthermore, the water-free photovoltaic cleaning drone is controlled to take off stably and reach a preset height;

[0179] After reaching the predetermined height, the waterless photovoltaic cleaning drone navigates along the preset path, adjusts the flight direction and altitude, and flies over the photovoltaic panel to be cleaned;

[0180] After reaching the target position, the drone hovers, and the flight control system 9 ensures its stability;

[0181] Obtain the conditions for removing adhered particles on the photovoltaic panel to be cleaned; obtain the minimum wind speed for removing adhered particles based on the conditions for removing adhered particles and the mechanical model of dust accumulation, input the minimum wind speed into the flight control system 9, obtain an electrical signal and transmit it to the electric regulator, the electric regulator converts the electrical signal into a three-phase AC signal and outputs it to motor 1 7, motor 2, motor 3 and motor 4; drive propeller blade 1 2, propeller blade 2, propeller blade 3 and propeller blade 4 to rotate to generate corresponding airflow, the corresponding airflow passes through the speed increasing and flow increasing duct 1 to generate a high-speed airflow, and the photovoltaic panel to be cleaned is cleaned with the high-speed airflow.

[0182] Furthermore, the design of the UAV speed-increasing and flow-increasing duct is based on the incompressible fluid continuity formula, which accelerates the airflow and generates a high-speed airflow by shrinking the cross-sectional area of ​​the duct from the inlet to the outlet. The expression of the incompressible fluid continuity is:

[0183] ρV1A1=ρV2A2

[0184]

[0185] Where A1 is the inlet area and A2 is the outlet area. The cross section of the duct perpendicular to its longitudinal central axis contracts smoothly from the inlet to the outlet. For example, in an illustrative example, the inlet area A1 of the duct designed by the above formula is 0.57m 2 , the outlet area A2 of the duct is 0.225m 2, the inlet and outlet contraction ratio is 0.395. In this example, the air velocity at the outlet after acceleration is about 2.5 times the velocity at the blade of the drone, which effectively increases the wind speed generated by the drone during flight. ρ is the air density of the flight environment, V1 is the air inlet air velocity, and V2 is the air outlet air velocity.

[0186] The expression of the deposition mechanics model is:

[0187] F ad =F e +F vdw +G y +F buoyancy

[0188] Among them, F ad is the main adhesion force of dust particles perpendicular to the solar panel surface, F e is the electrostatic force, F vdw is the van der Waals force, G y is the gravity component, F buoyancy is the buoyancy of microparticles in the air.

[0189] Furthermore, the rotation of propeller blades one, two, three and four produces corresponding airflow velocities u a The expression is:

[0190]

[0191] Among them, Cv is the dimensionless speed coefficient, N is the propeller speed (unit RPM, revolutions per minute), Dp is the propeller diameter, and ρ is the air density of the flight environment, which is related to the flight altitude.

[0192] The removal condition of the adhered particles is expressed as:

[0193]

[0194] Where k0 is the static friction coefficient, d p is the diameter of the dust particle, F n is the supporting force, and p0 is the adhesion force of the adhesion particles.

[0195] Preferably, the specific steps of flying over the photovoltaic panel to be cleaned include:

[0196] Acquire RGB images of photovoltaic panels to be cleaned based on drones;

[0197] Gaussian filtering is used to preprocess the RGB image of the photovoltaic panel to be cleaned to remove image noise and obtain a preprocessed RGB image;

[0198] Convert the preprocessed RGB image into an HSV image;

[0199] Determine the color threshold of photovoltaic panels;

[0200] Cutting the HSV image based on the color threshold and then performing dilation and corrosion processing to obtain a processed image;

[0201] The part of the processed image that matches the shape and size of the photovoltaic panel is retained, and the contours that do not match the area and shape are removed. Based on the Sobel filter, the edge area of ​​the photovoltaic panel to be cleaned is obtained;

[0202] The edge area of ​​the photovoltaic panel to be cleaned is represented in the RGB image of the photovoltaic panel to be cleaned, and edge detection is performed to obtain the cleaning area of ​​the photovoltaic panel to be cleaned. The drone flies above the photovoltaic panel to be cleaned according to the cleaning area of ​​the photovoltaic panel to be cleaned.

[0203] It can be understood that the flight control system 9 ensures its stability to prevent the drone from deviating from the target due to airflow disturbance or wind influence;

[0204] Preferably, the preset path navigation is a remote control instruction of an operator or a flight path pre-planned by a ground station;

[0205] Preferably, the specific steps of controlling the water-free photovoltaic cleaning drone to take off stably and reach a preset height in step 1 include:

[0206] Controlling the remote controller to send an operation instruction to the water-free photovoltaic cleaning drone; the operation instruction is transmitted to the drone via radio waves;

[0207] The drone transmits the operation instruction to the flight control system 9;

[0208] After receiving the operation command, the flight control system 9 performs a status check; the status check includes the status of the drone sensor, battery power, motor and electric regulator;

[0209] After the status check is completed, the flight control system 9 sends a low-frequency pulse signal to the ESC to start the corresponding motor, driving the corresponding propeller to rotate at a low speed;

[0210] The flight control system controls the four motors to accelerate synchronously and at the same time controls the attitude of the drone, allowing the drone to leave the ground, take off smoothly, and reach a predetermined height.

[0211] The take-off process of the drone in the present invention includes the flight control gradually increasing the motor speed, driving the propeller to rotate, and generating sufficient thrust to make the drone take off smoothly. After the drone is smoothly lifted off, the flight control automatically adjusts the flight direction and altitude according to the pre-set path navigation, flies to the sky above the photovoltaic panel to be cleaned, and after reaching the target position, the drone hovers above the photovoltaic panel. The flight control ensures that it hovers stably to avoid deviation from the target due to airflow disturbance or wind influence. The motor drives the propeller to generate high-speed, downward airflow. When the airflow passes through the speed-increasing and flow-increasing components, its flow rate is further accelerated to form a high-speed airflow. The high-speed airflow after the speed increase has a higher flow rate and cleaning effect, and can effectively remove dust and dirt on the surface of the photovoltaic panel.

[0212] The above are implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A water-free photovoltaic cleaning drone based on a dust accumulation mechanics model, characterized in that: include: Speed ​​increasing and flow increasing duct (1), carbon plate connecting assembly and drone; The speed increasing and flow increasing duct (1) is connected to the UAV via a carbon plate connecting assembly; The speed increasing and flow increasing duct (1) comprises a support arm assembly, a cross beam assembly and a skin (1-2); The support arm assembly and the cross beam assembly are connected to form a duct frame (1-1), and a cavity is formed in the duct frame (1-1); the skin (1-2) is respectively connected to the support arm assembly and the cross beam assembly; and the UAV is arranged in the cavity.

2. The water-free photovoltaic cleaning drone according to claim 1, characterized in that: The structure of the speed increasing and flow increasing duct (1) is an axisymmetric and center symmetric structure; The duct skeleton (1-1) defines the outline of the speed-increasing and flow-increasing duct (1); The cross section of the duct skeleton (1-1) is perpendicular to the longitudinal center axis of the speed-increasing and flow-increasing duct (1).

3. The water-free photovoltaic cleaning drone according to claim 1, characterized in that: The unmanned aerial vehicle comprises a flight control system (9), a motor assembly and a propeller blade assembly; The motor assembly includes a motor one (7); The propeller blade assembly includes a propeller blade one (2).

4. The water-free photovoltaic cleaning drone according to claim 3, characterized in that: The crossbeam assembly comprises at least two crossbeams (1-4); The at least two cross beams (1-4) are vertically arranged on the cross section along the longitudinal center axis of the speed increasing and flow increasing duct 1 to form a closed structure; The support arm assembly comprises at least two support arms (1-5); the at least two support arms (1-5) extend along the contour of the duct frame (1-1) in the longitudinal direction and are connected to each of the cross beams (1-4); the cross beams and the support arms together form a mesh structure, constituting a duct frame (1-1) with a stable structure.

5. A method for performing waterless photovoltaic cleaning using a waterless photovoltaic cleaning drone based on a dust accumulation mechanics model according to any one of claims 1 to 4, comprising: The water-free photovoltaic cleaning drone flies to the air above the photovoltaic panel to be cleaned, and is controlled by the flight control system (9) to hover stably; Obtaining conditions for removing particles adhering to a photovoltaic panel to be cleaned; Based on the removal condition of the adhered particles, a minimum wind speed for removing the adhered particles is obtained, and the minimum wind speed is input into a flight control system (9) to obtain a three-phase alternating current signal; The motor assembly receives a three-phase alternating current signal, driving the propeller blade assembly to rotate and generate a corresponding airflow; the corresponding airflow passes through a speed increasing and flow increasing duct (1) to generate a high-speed airflow, and the photovoltaic panel to be cleaned is cleaned using the high-speed airflow.

6. The water-free photovoltaic cleaning drone according to claim 5, characterized in that: The design of the UAV speed increasing and flow increasing duct is based on the continuity formula of incompressible fluid, which is expressed as: ρV1A1=ρV2A2 Among them, A1 is the inlet area, A2 is the outlet area, ρ is the air density of the flight environment, V1 is the air inlet air velocity, and V2 is the air outlet air velocity.

7. The water-free photovoltaic cleaning drone according to claim 5, characterized in that: The expression of the deposition mechanics model is: F ad =F e +F vdw +G y +F buoyancy Among them, F ad is the main adhesion force of dust particles perpendicular to the solar panel surface, F e is the electrostatic force, F vdw is the van der Waals force, G y is the gravity component, F buoyancy is the buoyancy of microparticles in the air.

8. The water-free photovoltaic cleaning drone according to claim 5, characterized in that: The expression for the flow velocity of the corresponding airflow generated by the rotation of the propeller blade assembly is: Wherein, Ua represents the airflow velocity generated by any propeller blade in the propeller blade assembly, Cv is the dimensionless velocity coefficient, N is the propeller speed, Dp is the propeller diameter, and ρ is the air density of the flight environment.

9. The water-free photovoltaic cleaning drone according to claim 5, characterized in that: The cleaning area of ​​the photovoltaic panel to be cleaned is determined, and the drone flies to the air above the photovoltaic panel to be cleaned according to the cleaning area of ​​the photovoltaic panel to be cleaned. The specific steps include: Acquire RGB images of the photovoltaic panels to be cleaned based on the water-free photovoltaic cleaning drone; Gaussian filtering is used to preprocess the RGB image of the photovoltaic panel to be cleaned and converted into an HSV image; Determine the color threshold of photovoltaic panels; Processing the HSV image based on the color threshold to obtain a processed image; Obtaining an edge area of ​​the photovoltaic panel to be cleaned based on the processed image; The edge area of ​​the photovoltaic panel to be cleaned is represented in the RGB image of the photovoltaic panel to be cleaned, and edge detection is performed to obtain the cleaning area of ​​the photovoltaic panel to be cleaned. The drone flies above the photovoltaic panel to be cleaned according to the cleaning area of ​​the photovoltaic panel to be cleaned.

10. The water-free photovoltaic cleaning drone according to claim 5, characterized in that: The specific steps of controlling the drone to take off stably and reach a preset height in step 1 include: The flight control system (9) receives the operation instruction and performs a status check; After the status check is completed, the flight control system (9) sends a low-frequency pulse signal to the electric speed controller to start the corresponding motor, driving the corresponding propeller to rotate at a low speed; The flight control system (9) controls the synchronous acceleration of each motor in the motor assembly and controls the attitude of the drone at the same time, so that the drone leaves the ground, takes off smoothly, and reaches a predetermined height.

Images