Method and System for Cross-Domain Scheduling of Rotor UAVs for Distributed Photovoltaic Cleaning Carts

Abstract

The present invention discloses a method and system for cross-domain scheduling of a distributed photovoltaic cleaning cart by a rotor unmanned aerial vehicle, belonging to the technical field of unmanned aerial vehicle applications. The system includes a cleaning cart, a rotor unmanned aerial vehicle, a magnetic induction positioning device, an ultrasonic sensor, a vision sensor, and a GPS module. The steps of the method include: the cleaning cart returns to the parking area under the navigation of the GPS module, and finely adjusts the relative position between the cleaning cart and the center of the parking area; the rotor unmanned aerial vehicle flies to above the parking area through the positioning of the GPS module, detects the cleaning cart through YOLOV5m, and adjusts the relative position between the rotor unmanned aerial vehicle and the center of the parking area, and performs rough adjustment including a hovering mode and a second-stage rough adjustment; the rotor unmanned aerial vehicle enters the fine adjustment mode, and when the ultrasonic ranging height is less than a certain value, the rotor unmanned aerial vehicle shuts down and lands; the present invention can achieve precise positioning and assisted landing of the unmanned aerial vehicle and the cleaning cart, and realize precise cross-domain scheduling of the distributed photovoltaic cleaning cart.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle applications, and particularly to a method and system for cross-domain scheduling of a distributed photovoltaic cleaning cart by a rotary-wing unmanned aerial vehicle. Background Art

[0002] In recent years, photovoltaic power generation has been increasingly applied, and the cleaning problem of solar panels has attracted much attention. For the cleaning of distributed photovoltaic panels, the crawler-type photovoltaic cleaning cart currently has the best cleaning effect and is the most widely used. However, this cleaning solution cannot perform cross-domain scheduling autonomously and generally has a high cost.

[0003] With the development of unmanned aerial vehicle technology, unmanned aerial vehicles have been widely practiced in transportation at present. The existing unmanned aerial vehicle transportation photovoltaic cleaning cart solutions have at least the following problems:

[0004] (1) Relying on a single GPS positioning leads to large positioning errors and low accuracy; (2) There is a lack of effective auxiliary means during the landing of the unmanned aerial vehicle, and it is easy to lose the target and fail to recognize due to the change of perspective; (3) Since photovoltaic panels are often inclined, and the existing structure for docking and fixing the unmanned aerial vehicle and the cleaning cart is simple, the relative position cannot be effectively adjusted and firmly connected, and the requirements for precise positioning, stable landing and reliable docking and transportation cannot be met. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a system for cross-domain scheduling of a distributed photovoltaic cleaning cart by a rotary-wing unmanned aerial vehicle to solve the above problems.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A system for cross-domain scheduling of a distributed photovoltaic cleaning cart by a rotary-wing unmanned aerial vehicle includes a cleaning cart, a rotary-wing unmanned aerial vehicle, a magnetic induction positioning device, an ultrasonic sensor, a vision sensor and a GPS module. Among them, the magnetic induction positioning device consists of a detection coil and a permanent magnet. The permanent magnet is located at the center of the parking area on the photovoltaic panel, and the detection coil is arranged at the bottom of the cleaning cart; the ultrasonic sensor and the vision sensor are both arranged at the bottom of the main body of the rotary-wing unmanned aerial vehicle, the GPS module is installed inside the rotary-wing unmanned aerial vehicle, and a fly landing pad for the rotary-wing unmanned aerial vehicle to land is arranged on the top of the cleaning cart.

[0007] The magnetic induction positioning device composed of the detection coil and the permanent magnet is used for the precise parking of the cleaning cart relative to the photovoltaic panel; and the self-centering gripper mechanism is used for the relative position adjustment and connection between the unmanned aerial vehicle and the cart.

[0008] As a preferred technical solution, a self-centering gripper mechanism is further provided on the landing and parking pad. The self-centering gripper mechanism includes a return spring provided with a guide shaft, symmetric centering crank sliders, V-shaped blocks, a frame, a driving servo, a magnet, and a magnetic sensor. Among them, the magnet is placed on the positioning post; the magnetic sensor is located at the center of the frame, and the frame is provided with threaded holes for screw connection with the trolley; there are two V-shaped blocks which are symmetrically arranged, and the V-shaped blocks are connected to the guide shaft, and the return movement is responsible for the return movement by the return spring; the output shaft of the driving servo is connected to the symmetric centering crank slider, and the V-shaped block is driven to move by the linkage rod of the symmetric centering crank slider.

[0009] After the UAV lands on the landing and parking pad, the driving servo drives the symmetric centering crank slider to drive the V-shaped blocks to clamp the four positioning posts of the UAV along the guide shaft; the magnet is placed on the positioning post; the magnetic sensor is located at the center of the frame, and after contacting the magnet of the positioning post, it transmits a contact signal; the driving servo receives the contact signal and drives the symmetric centering crank slider.

[0010] The second object of the present invention is to provide a method for cross-domain scheduling of distributed photovoltaic cleaning trolleys using the above system, including the following steps:

[0011] S100. The cleaning trolley returns to the parking area under the navigation of the GPS module, and further finely adjusts the relative position between the cleaning trolley and the center of the parking area according to the magnetic induction positioning device;

[0012] S200. The rotary UAV flies above the parking area through the positioning of the GPS module, detects the cleaning trolley through YOLOV5m, and adjusts the relative position between the rotary UAV and the center of the landing and parking pad, and enters the rough adjustment of the first stage including the hover mode;

[0013] S300. The rotary UAV performs the second stage of rough adjustment according to the detected auxiliary vehicle logo and the ultrasonic ranging result;

[0014] S400. The rotary UAV enters the fine adjustment mode. When the ultrasonic ranging height is less than , the rotary UAV shuts down and lands.

[0015] Among them, the ultrasonic ranging height refers to the relative distance in the vertical direction between the center of the downward-looking camera of the rotary UAV and the landing and parking pad. Among them, refers to: whether to send a "re-land" instruction, ; refers to: the height at which autonomous landing starts, .

[0016] As a preferred technical solution, in step S100, the specific method is:

[0017] First, the parking area on the solar panel is square, and the center of the parking area corresponds to the GPS coordinates of the parking area. The cleaning cart receives the GPS coordinates of the parking area and navigates to the parking area according to GPS positioning technology.

[0018] Then, a coil serving as a detector is located at the bottom of the cleaning cart. A permanent magnet is selected as a magnetic field source with stable intensity and installed at the center of the parking area of the photovoltaic panel. When the cleaning cart moves, the relative position of the cleaning cart changes with respect to the center position of the parking area, generating a changing magnetic field. This changing magnetic field induces an electromotive force in the detection coil. By measuring the magnitude and direction of this electromotive force, the relative position between the rotor unmanned aerial vehicle and the center of the parking area is determined. After the adjustment is completed, when the electromotive force is 0, a parking completion signal is sent to the control center. After receiving the parking completion signal, the control center sends a start command to the rotor unmanned aerial vehicle.

[0019] As a preferred technical solution, in step S200, the specific method is as follows:

[0020] The rotor unmanned aerial vehicle uses GPS for preliminary navigation and positioning to hover above the center of the parking area. OpenCV is used to open the downward-looking camera carried by the rotor unmanned aerial vehicle, and the cleaning cart is detected through the YOLOV5s model. At the same time, the ultrasonic sensor measures the distance, and the relative height between the center of the downward-looking camera of the rotor unmanned aerial vehicle and the parking pad is obtained.

[0021] The parking pad on the top of the cleaning cart is square. An auxiliary vehicle marker is set at the midpoint of each of the four sides of the parking pad. The auxiliary vehicle marker is an AprilTag, different from the ID number of the guiding landmark, and the ID numbers of the four auxiliary vehicle markers are also different from each other. A center marker is provided at the center position of the parking pad, and the center marker is an AprilTag. A nested center marker is also set at the exact center position of the center marker. The nested center marker is an AprilTag, and the ID number of the nested center marker has not been used before.

[0022] a) The rotor unmanned aerial vehicle adopts adaptive control. At each hovering height, the rotor unmanned aerial vehicle sets a time threshold. If the rotor unmanned aerial vehicle searches for any one of the auxiliary vehicle markers 5 - 8 times within the detection time, it enters step S300 (that is, whether it can be recognized within this time interval, and enters S300 according to this result); b) If only the cleaning cart is detected, according to the coordinate information of the cleaning cart detected by YOLOV5m and the ranging result of the ultrasonic sensor, a threshold is set for the adjustment of the horizontal plane position. After completion, it descends at a speed of 20.0 - 20.5 cm / s and enters the hovering mode again.

[0023] Repeat the above steps a) and b) until any one of the auxiliary vehicle logos is recognized.

[0024] Considering that the code may not be recognized at the beginning of the landing due to a relatively high height, the descent is carried out step by step. Reduce the height and repeat the steps of staying and recognizing - horizontal adjustment - descent, as shown in Figure 4 .

[0025] As a preferred technical solution, in step S300, the specific method is: in step S300, the specific method is: c) The rotary-wing unmanned aerial vehicle adopts adaptive control, descends at a speed of 12.0 - 12.5 cm / s in the height direction, and makes adjustments on the horizontal plane according to the auxiliary vehicle logo read by OpenCV;

[0026] If the center logo is read 5 - 8 times during the above step c), enter step S400; otherwise, maintain the motion state of the above step c);

[0027] There is a height threshold during the landing phase , which refers to: whether to send a "re-land" instruction, ; when the ranging result of the ultrasonic sensor is less than , but the center logo has still not been detected, the rotary-wing unmanned aerial vehicle sends a "re-land" instruction to the control center and returns to the height when it just entered step S300, and re-performs the landing detection and adjustment.

[0028] As a preferred technical solution, in step S400, the specific method is: the landing speed of the rotary-wing unmanned aerial vehicle is 8.0 - 8.3 cm / s; when the nested center logo is detected, the landing speed becomes 4.0 - 4.2 cm / s. At this stage, when the ultrasonic ranging height is less than , the rotary-wing unmanned aerial vehicle shuts down the motor and lands by relying on its own gravity;

[0029] After the rotary-wing unmanned aerial vehicle completes the precise landing, the rotary-wing unmanned aerial vehicle uses a self-centering gripper mechanism to grab the cleaning trolley.

[0030] First of all, the present invention precisely controls the landing position of the rotary-wing unmanned aerial vehicle by controlling it stage by stage;

[0031] Then, after the rotary-wing unmanned aerial vehicle lands, through the self-centering gripper structure configured on the flying landing pad, the relative position between the rotary-wing unmanned aerial vehicle and the distributed photovoltaic cleaning trolley is further adjusted, and the four legs of the rotary-wing unmanned aerial vehicle are grabbed and fixed;

[0032] The present invention realizes precise landing of the drone by the precise parking of the trolley and the visual recognition of the drone, so that the drone lands on the top of the trolley within a certain error range. Within this error range, the self-centering gripper of the present invention can adjust the drone; since the photovoltaic panel is inclined, the drone landing platform is also inclined, which is prone to the risk of slipping. The present invention relies on the self-centering gripper to allow the relative position error between the drone and the trolley and protect the drone, reducing or even preventing the risk of slipping and facilitating subsequent cross-domain scheduling.

[0033] The present invention uses a magnetic induction positioning device to further precisely adjust the position of the cleaning trolley on the basis of the preliminary GPS positioning, solving the problems of large positioning error and low accuracy relying only on GPS positioning.

[0034] The present invention uses GPS positioning and machine vision-assisted landing, and calls OpenCV to capture and recognize Apriltag tags.

[0035] Multiple Apriltag tags of the present invention cooperate with each other and combine with ultrasonic ranging to control the landing state of the rotor drone in stages, solving the problems of target loss and recognition failure due to the sudden reduction of the viewing angle during the landing process of the drone.

[0036] The present invention uses a self-centering gripper structure to further adjust the relative position between the rotor drone and the distributed photovoltaic cleaning trolley, and initially fixes the four legs of the rotor drone by clamping with the gripper, and then further fixes it by using an electromagnetic induction device.

[0037] Compared with the prior art, the advantages of the present invention are as follows:

[0038] (1) Precise positioning:

[0039] The present invention adopts a multi-stage and multi-technology fusion positioning method: first, use GPS navigation to make the distributed photovoltaic cleaning trolley return to the parking area, and then finely adjust its relative position with the center C through a magnetic induction positioning device; during the landing process of the rotor drone, first locate above the parking area through GPS, and then use OpenCV to analyze and guide the landmark AprilTag (including the guiding landmarks at the four corners of the parking area, the auxiliary vehicle marks at the midpoints of the four sides of the flying and parking apron, the center mark at the center of the flying and parking apron, and the nested center mark nested in the center of the center mark) for position adjustment, and at the same time combine ultrasonic sensor ranging assistance; solving the problems of large positioning error and low accuracy in the prior art relying only on a single GPS positioning.

[0040] (2) Assisted landing:

[0041] The present invention effectively solves the problems of target loss and recognition failure caused by perspective changes, as well as the lack of effective auxiliary means during the landing of an unmanned aerial vehicle (UAV) and the resulting problems prone to occur due to perspective changes, by setting up detection and adjustment mechanisms at different stages during the landing process of the rotary-wing UAV, utilizing a variety of landmark tags and adaptive control technologies, and combining ultrasonic ranging to control the landing state in stages.

[0042] (3) Docking is stable and reliable:

[0043] After the rotary-wing UAV lands, the present invention further adjusts the relative position with the distributed photovoltaic cleaning cart by using the self-centering clamping structure configured on the flying landing pad, and clamps the four positioning columns of the rotary-wing UAV for fixation, solving the problems in the prior art that the structure is simple when the UAV is docked and fixed with the cleaning cart, and it is unable to effectively adjust the relative position and stably connect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 Schematic diagram of the parking area for the embodiments of the present invention;

[0045] Figure 2 Schematic diagram of the flying landing pad for the embodiments of the present invention;

[0046] Figure 3 Flowchart of the present invention;

[0047] Figure 4 Specific flowchart of step S200;

[0048] Figure 5 Specific flowcharts of steps S300 and S400;

[0049] Figure 6 Structural diagram of the cleaning cart;

[0050] Figure 7 Structural diagram of the self-centering clamping mechanism;

[0051] Figure 8 For Figure 7 A-A sectional view;

[0052] Figure 9 For Figure 7 Structural diagram of the symmetric centering crank-slider in

[0053] Figure 10 Overall schematic diagram when the embodiments of the present invention are implemented;

[0054] Figure 11 Structural schematic diagram of the rotary-wing UAV

[0055] Figure 12 Sectional view of the positioning column;

[0056] In the figure: 1. positioning column a; 2. return spring; 3. symmetric centering crank-slider; 4. V-shaped block; 5. frame; 6. driving servo; 7. magnet; 8. magnetic sensor; 9. positioning column b; 10. positioning column c; 11. positioning column d. Specific embodiments

[0057] The present invention will be further described below in conjunction with embodiments.

[0058] Embodiment 1:

[0059] Refer to Figure 3 , a method for cross-domain scheduling of a distributed photovoltaic cleaning cart by a rotor UAV, comprising the following steps:

[0060] S100. The distributed photovoltaic cleaning cart returns to the parking area under GPS navigation and further finely adjusts the relative position between the distributed photovoltaic cleaning cart and the center C of the parking area according to the magnetic induction positioning device, specifically as follows:

[0061] In this step S100, in combination with Figure 1 , the parking area on the solar panel is square, with a size of 80 cm × 80 cm; the center C of the parking area corresponds to the GPS coordinates of the parking area;

[0062] In this embodiment, after the distributed photovoltaic cleaning cart completes the cleaning task on the current solar panel, it sends a task completion signal to the control center; the control center, according to the received signal, traverses the array storing the parking area GPS coordinates of all solar panels in this area, and feeds back the parking area GPS coordinates of the current numbered solar panel to the cleaning cart and the rotor UAV in the standby state;

[0063] The distributed photovoltaic cleaning cart receives the parking area GPS coordinates and navigates to this parking area according to GPS positioning technology;

[0064] The coil serving as the detector is located at the bottom of the cleaning cart, and a permanent magnet is selected as a magnetic field source with stable intensity and installed at the center position of the parking area of the photovoltaic panel; when the cleaning cart moves, the relative position between the cleaning cart and the center position of the parking area changes, generating a changing magnetic field, and this changing magnetic field will induce an electromotive force on the detection coil; by measuring the magnitude and direction of this electromotive force, the relative position between the rotor UAV and the center of the parking area is determined; after the adjustment is completed, an electromotive force of 0 is obtained, and a parking completion signal is sent to the control center; after receiving the parking completion signal, the control center sends a start command to the rotor UAV;

[0065] S200. The rotor UAV flies above the parking area through GPS positioning, detects the distributed photovoltaic cleaning cart through YOLOV5m, and adjusts the relative position of the rotor UAV relative to the center C of the parking area, entering the rough adjustment in the first stage including the hovering mode, specifically as follows:

[0066] The rotary-wing UAV uses GPS for preliminary navigation and positioning to hover above the center C of the parking area. The downward-looking camera carried by the rotary-wing UAV is opened by OpenCV, and the distributed photovoltaic cleaning cart is detected through the YOLOV5s model. At the same time, the ultrasonic sensor measures the distance to obtain the relative height between the center of the downward-looking camera of the rotary-wing UAV and the parking pad.

[0067] It should be noted that the experimental environment of this embodiment is located in Chengdu, Sichuan. After consulting relevant materials, it is found that at this latitude and longitude, the best installation angle of the distributed solar panels is 16°, as Figure 10 shown; the lightweight model YOLOV5m used in the present invention can better balance the model size and detection speed under the experimental conditions of this experiment. When training the YoloV5m model, only one class is marked. To improve the detection performance, images of the distributed photovoltaic cleaning cart on the photovoltaic panel with an inclination angle of 16° under different lighting conditions, different shooting angles, and different shooting heights are collected to enrich the data set.

[0068] Combined with Figure 2 , the top parking pad of the distributed photovoltaic cleaning cart is a square with a size of 50 cm × 50 cm. The auxiliary vehicle marks are AprilTags of the TAG36H11 series with a size of 15 cm × 15 cm each. They are different from the ID numbers of the guiding landmarks, and the ID numbers of the four auxiliary vehicle marks are also different from each other. They are placed at the midpoints of the four sides of the parking pad. The center mark is an AprilTag of the TAG16H5 series with a size of 10 cm × 10 cm, placed at the center of the parking pad. The nested center mark is an AprilTag of the TAG36H11 series with a size of 5 cm × 5 cm, and the ID number of this tag has not been used before. It is nested in the center of the center mark.

[0069] In step S200, the rotary-wing UAV adopts adaptive control to suppress the uncertainties in the dynamics of the UAV and the external disturbances caused by changing environmental factors. The rotary-wing UAV sets a time threshold at each hovering height. If the rotary-wing UAV searches for any one of the auxiliary vehicle marks 5 - 8 times within this detection time, it enters step S300. If only the distributed photovoltaic cleaning cart is detected, according to the coordinate information of the distributed photovoltaic cleaning cart detected by YOLOV5m and the ranging result of the ultrasonic sensor, a threshold is set for the adjustment of the horizontal position. After completion, it descends at a speed of 20 cm / s , and enters the hovering mode again, repeating the above operations until any one of the auxiliary vehicle marks is recognized.

[0070] It should be noted that the hovering stage is set to more accurately judge the relative position between the current rotor UAV and the center C and better adjust in the horizontal plane direction; knowing the ID number of the guiding landmark can obtain the relative position between the landmark and the nested center landmark;

[0071] Combined with Figure 4 , in step S200, during the landing stage of the rotor UAV at a speed of 20 cm / s, according to the icons detected by the downward-looking camera and adaptive control, the rotor UAV still makes adjustments in the horizontal plane direction. If any one of the auxiliary vehicle marks is searched for 5 - 8 times during this stage, it enters step S300;

[0072] S300. The rotor UAV makes a second-stage rough adjustment according to the detected and read auxiliary vehicle marks and the ultrasonic ranging results;

[0073] Combined with Figure 2 , the rotor UAV adopts adaptive control, descends at a speed of 12 cm / s in the height direction, and makes adjustments in the horizontal plane according to the auxiliary vehicle marks read by OpenCV; if the center mark is read 5 - 8 times during this process, it enters step S400; otherwise, it maintains the above motion state;

[0074] Combined with Figure 5 , it should be noted that there is a height threshold during the landing stage ; when the ranging result of the ultrasonic sensor is less than , but the center mark has not been detected yet, the rotor UAV sends a "re-landing" instruction to the control center and returns to the height when it just entered step S300 to re-perform landing detection and adjustment;

[0075] S400. The rotor UAV enters the fine-tuning mode. When the ultrasonic ranging height is less than , the rotor UAV motor is turned off for landing;

[0076] In step S400, combined with Figure 5 , the landing speed of the rotor UAV is 8 cm / s; when the nested center mark is detected, the landing speed becomes 4 cm / s. During this stage, combined with Figure 10 , when the ultrasonic ranging height is less than , the rotor UAV turns off the motor and lands by its own gravity;

[0077] It should be noted that , affected by the FOV of the downward-looking camera and the wind speed in the working environment, etc., it needs to be selected according to the actual situation;

[0078] After the rotor UAV completes precise landing, it grabs the distributed photovoltaic cleaning trolley. The specific operation process is as follows:

[0079] Refer toFigure 6 , the distributed photovoltaic cleaning trolley includes a self - centering clamping mechanism arranged on its top and a rolling brush at the bottom. Among them, the self - centering clamping mechanism is as shown in Figure 7 and Figure 8 , and is composed of a return spring 2 with a guide shaft, a symmetric centering crank - slider 3, a V - block 4, a frame 5, a driving servo 6, a magnet 7, and a magnetic sensor 8. Among them, the driving servo 6 drives the symmetric centering crank - slider 3, driving the V - block 4 to clamp the positioning column a1 along the guide shaft of the return spring 2; the magnet 7 is placed on the positioning column a1; the magnetic sensor 8 is located at the center of the frame 5 and transmits a contact signal after contacting the magnet 7 of the positioning column a1; the frame 5 is provided with threaded holes for screw connection with the distributed photovoltaic cleaning trolley; Combining Figure 6 , the self - centering clamping mechanisms are respectively installed at positions A, B, C, and D of the hovering and landing pad; Combining Figure 11 , the rotary wing unmanned aerial vehicle includes a positioning column a1, a positioning column b9, a positioning column c10, and a positioning column d11; the positioning column b9 is connected to the self - centering clamping mechanism at position B, the positioning column c10 is connected to the self - centering clamping mechanism at position C, and the positioning column d11 is connected to the self - centering clamping mechanism at position D. The above - mentioned connection methods are all the same as the connection working method of the positioning column a1 and the self - centering clamping mechanism at position A described in detail above.

[0080] Among them, referring to Figure 9 , the symmetric centering crank - slider 3 includes a driving crank 31, a connecting rod 32, and a linkage rod 33; during operation, the servo drives the crank to rotate counterclockwise, causing the connecting rod to drive the linkage rod to move towards the center along the limit groove of the frame; during this process, the linkage rod drives the V - block 4 to move towards the center to clamp the positioning column a1;

[0081] After the rotary wing unmanned aerial vehicle lands precisely, it triggers the magnetic sensor, and the four driving servos 6 for self - centering clamping are activated, driving the symmetric centering crank - slider 3 to rotate, thereby realizing the V - block 4 to move towards the middle along the guide axis, so that the four positioning columns of the rotary wing unmanned aerial vehicle are adjusted in both horizontal and vertical positions; after the four positioning columns are all firmly clamped, the four driving servos 6 stop working; the motor of the rotary wing unmanned aerial vehicle starts and carries the distributed photovoltaic cleaning trolley to the GPS coordinate point given by the control center;

[0082] It should be noted that in this experimental environment, the installation angle of the distributed solar panels is 16°, and after multiple tests, the selection is 10 cm; at this height, when the motor is turned off and it lands on the solar panel with an inclination of 16°, the error between the center of the rotary wing unmanned aerial vehicle and the center of the hovering and landing pad can be adjusted by the self - centering clamping;

[0083] The motor of the rotary wing unmanned aerial vehicle starts and carries the distributed photovoltaic cleaning trolley to the GPS coordinate point given by the control center;

[0084] It should be noted that the GPS coordinate points given by the control center are the coordinates of the parking area corresponding to the next solar panel to be cleaned; for the process of cross-domain scheduling of the distributed photovoltaic cleaning vehicle, please refer to Figure 3 ; for the motor startup of the rotor unmanned aerial vehicle, according to a method for cross-domain scheduling of a distributed photovoltaic cleaning vehicle by a rotor unmanned aerial vehicle disclosed in the present invention, the system enters step S100.

[0085] Refer to Figure 3 , after the system completes step S400, that is, the rotor unmanned aerial vehicle motor is turned off, the cross-domain scheduling task of the distributed photovoltaic cleaning vehicle by the rotor unmanned aerial vehicle is completed, the unmanned aerial vehicle free-falls, and the magnet installed on its foot triggers the magnetic sensor in the middle of the self-centering fixture of the cleaning vehicle, driving the steering gear 6 to drive the symmetric centering crank-slider 3, so that the self-centering fixture clamps the positioning column, and the steering gear 6 stops working. The rotor unmanned aerial vehicle has completed the placement of the distributed photovoltaic cleaning vehicle; the rotor unmanned aerial vehicle motor starts, and under GPS navigation, the rotor unmanned aerial vehicle flies back to the standby point.

[0086] According to Figure 11 , the rotor unmanned aerial vehicle includes four identical positioning columns, namely positioning column a1, positioning column b9, positioning column c10, and positioning column d11. The structure of the positioning column is as Figure 12 shown; the above-mentioned positioning columns are arranged at the positions of the four feet of the rotor unmanned aerial vehicle. Magnets are installed on the foot positioning columns, and there is a magnetic sensor in the self-centering fixture of the cleaning vehicle. According to the working principle of the magnetic sensor, when the magnetic field is enhanced to a certain extent, a high voltage is output (equivalent to the function of a switch). After the rotor unmanned aerial vehicle lands on the top of the cleaning vehicle, due to the short distance and strong magnetic field, the magnetic sensor is driven to output a high voltage, starting the steering gear 6. The steering gear 6 drives the symmetric centering crank-slider, adjusts the positioning column through the fixture (that is, the position of the unmanned aerial vehicle relative to the vehicle) and clamps the positioning column; after the steering gear 6 works for 20 s to 25 s, it stops working. At this time, the relative position adjustment of the vehicle relative to the unmanned aerial vehicle has been completed, and the connection between the vehicle and the unmanned aerial vehicle has been completed, and it can reach the next location through GPS.

[0087] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for cross-domain dispatching of distributed photovoltaic cleaning vehicles, characterized in that: The method is carried out using the following system: It includes a cleaning trolley, a rotary-wing UAV, a magnetic induction positioning device, an ultrasonic sensor, a visual sensor and a GPS module, wherein the magnetic induction positioning device is composed of a detection coil and a permanent magnet, the permanent magnet is located at the center of the parking area on the photovoltaic panel, and the detection coil is arranged at the bottom of the cleaning trolley; the ultrasonic sensor and the visual sensor are both arranged at the bottom of the main engine of the rotary-wing UAV, the GPS module is installed inside the rotary-wing UAV, and a landing pad for the rotary-wing UAV to land is arranged on the top of the cleaning trolley; The parking area is an inclined surface; A self-centering clamping mechanism is also provided on the landing pad, and the self-centering clamping mechanism includes a return spring provided with a guide shaft, a symmetrically centered crank slider, two symmetrically arranged V-blocks, a frame, a driving servo, a magnet and a magnetic sensor. The rotor UAV is provided with a positioning column, wherein the magnet is placed on the positioning column; the magnetic sensor is located at the center of the frame, and the frame is provided with a threaded hole for screw connection with the trolley; there are two V-blocks and they are symmetrically arranged, and the V-blocks are connected to the guide shaft, and the return spring is responsible for the return movement; the output shaft of the driving servo is connected to the symmetrically centered crank slider, and the linkage rod of the symmetrically centered crank slider drives the V-block to move; The method comprises the following steps: S100, the cleaning trolley returns to the parking area under the navigation of the GPS module, and further fine-adjusts the relative position of the cleaning trolley and the center of the parking area according to the magnetic induction positioning device; S200, the rotor drone flies above the parking area through the positioning of the GPS module, detects the cleaning car through YOLOV5m, and adjusts the relative position of the rotor drone and the center of the flying pad, entering the first stage of coarse adjustment including hovering mode; The S300 and the rotor UAV perform the second stage of rough adjustment based on the auxiliary vehicle logo and ultrasonic ranging results read by the detection; S400, rotor drone enters fine adjustment mode, when ultrasonic ranging height is less than When the rotor UAV motor is turned off for landing, the ultrasonic ranging height refers to the relative distance between the center of the rotor UAV's downward-looking camera and the landing pad in the vertical direction. It means: the altitude at which autonomous descent begins. 0.6m to 0.8m; In step S100, the specific method is: First, the parking area on the solar panel is square, and the center of the parking area corresponds to the GPS coordinates of the parking area. The cleaning car receives the GPS coordinates of the parking area and navigates to the parking area based on GPS positioning technology; Then, the coil serving as a detector is located at the bottom of the cleaning trolley, and a permanent magnet is selected as a magnetic field source with stable strength and installed at the center of the parking area of ​​the photovoltaic panel; when the cleaning trolley moves, the position of the cleaning trolley relative to the center of the parking area changes, generating a changing magnetic field, which will induce an electromotive force on the detection coil; by measuring the size and direction of the electromotive force, the relative position of the cleaning trolley and the center of the parking area is determined; after the adjustment is completed, the electromotive force is 0, and a parking completion signal is sent to the control center; after receiving the parking completion signal, the control center sends a start command to the rotor UAV.

2. The method according to claim 1, characterized in that In step S200, the specific method is: The rotary-wing UAV uses GPS for preliminary navigation and positioning to hover above the center of the parking area; OpenCV is used to open the downward-looking camera carried by the rotary-wing UAV, and the cleaning vehicle is detected through the YOLOV5m model; at the same time, the ultrasonic sensor performs distance measurement to obtain the relative height between the center of the downward-looking camera of the rotary-wing UAV and the landing pad; The landing pad on the top of the cleaning trolley is square; an auxiliary vehicle tag is set at the midpoint of each of the four sides of the landing pad, and the auxiliary vehicle tag is AprilTag, which is different from the ID number of the guide landmark, and the ID numbers of the four auxiliary vehicle tags are also different; a center tag is set at the center of the landing pad, and the center tag is AprilTag; a nested center tag is also set in the middle of the center tag, and the nested center tag is AprilTag, and the ID number of the nested center tag has not been used before; a) The rotor UAV adopts adaptive control. At each hovering height, the rotor UAV sets The time threshold is 1.0s to 1.5s. If the rotor drone searches for any auxiliary vehicle logo 5-8 times within the detection time, it goes to step S300; b) If only the cleaning vehicle is detected, set the coordinate information of the cleaning vehicle detected by YOLOV5m and the ranging result of the ultrasonic sensor The threshold of 3.0s to 3.5s is used to adjust the horizontal position. After completion, it descends at a speed of 20.0-20.5cm / s 1.0s to 1.5s, and then enters the hovering mode again; Repeat steps a) and b) until any auxiliary vehicle logo is recognized.

3. The method according to claim 2, characterized in that In step S300, the specific method is as follows: c) the rotor drone adopts adaptive control, lands at a speed of 12.0-12.5 cm / s in the height direction, and makes adjustments on the horizontal plane according to the auxiliary vehicle logo read by OpenCV; If the center mark is read 5-8 times during step c), then the process proceeds to step S400; otherwise, the motion state of step c) is maintained; There is a height threshold during the landing phase , It means: whether to send the "re-landing" command, 2.2m to 2.5m; when the ultrasonic sensor distance measurement result is less than , but the center mark is still not detected, the rotor UAV sends a "re-landing" command to the control center, and returns to the altitude just entered into step S300, and re-performs landing detection and adjustment.

4. The method according to claim 2, characterized in that: In step S400, the specific method is: the landing speed of the rotor drone is 8.0-8.3 cm / s; when the nested center mark is detected, the landing speed becomes 4.0-4.2 cm / s. At this stage, when the ultrasonic ranging height is less than , the rotors are unmanned and the motors are turned off, and the aircraft lands by its own gravity; After the rotary-wing UAV completes precise landing, the rotary-wing UAV adopts a self-centering gripping mechanism to grab the cleaning trolley.

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