An Unmanned Aerial Vehicle-Based Inspection Path Planning Method for Wind Turbine Blades

Abstract

The present invention relates to a method for planning an inspection path of a wind turbine blade based on an unmanned aerial vehicle, comprising the following steps: controlling the unmanned aerial vehicle to fly near the hub of the target wind turbine, facing the center of the hub, adjusting the distance from the center of the hub by means of laser ranging carried on the unmanned aerial vehicle, hovering the unmanned aerial vehicle and obtaining the position information of the unmanned aerial vehicle at this time as initial position data, and obtaining the blade image of the target wind turbine by means of the image acquisition device carried on the unmanned aerial vehicle; identifying the included angle data between each blade of the current target wind turbine and the vertical direction based on the blade image of the target wind turbine; calculating the position data of each blade of the target wind turbine according to the initial position data of the unmanned aerial vehicle, the included angle data between each blade of the target wind turbine and the vertical direction, and the parameter data of the blade; and planning the inspection path of the unmanned aerial vehicle based on the position data of each blade of the target wind turbine and the initial position data of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to a method for planning an inspection path for blades of a wind turbine based on an unmanned aerial vehicle, and belongs to the technical field of inspection of wind turbine blades. Background Art

[0002] Given the increasing dependence on renewable energy, more wind turbines are currently being installed and relied upon for power generation compared to the past. Wind turbines face conventional obstacles such as rocks, dust, and blade corrosion caused by rain, air pollution, lightning, etc. Due to their design, even a small amount of leading-edge corrosion on the blade will have a negative impact on the performance and power generation capacity of the wind turbine.

[0003] To ensure the safe and efficient operation of wind turbines, routine inspections of the blades of wind turbines are required to ensure their normal operation. Currently, the inspection of wind turbine blades usually requires one or more skilled employees. Such manual inspections are difficult to comprehensively observe the overall situation of the blades of the unmanned aerial vehicle, and manual inspections are time-consuming and laborious, and there may also be casualties. Summary of the Invention

[0004] To solve the problems existing in the above-mentioned prior art, the present invention proposes a method for planning an inspection path for blades of a wind turbine based on an unmanned aerial vehicle, which uses the unmanned aerial vehicle to inspect the blades of the wind turbine, so that the fan blades can stop at any angle during the inspection process, and the inspection efficiency is high.

[0005] The technical solution of the present invention is as follows:

[0006] On the one hand, the present invention provides a method for planning an inspection path for blades of a wind turbine based on an unmanned aerial vehicle, including the following steps:

[0007] Control the unmanned aerial vehicle to fly near the hub of the target wind turbine, face the center of the hub, adjust the distance from the center of the hub through the laser rangefinder carried on the unmanned aerial vehicle, hover the unmanned aerial vehicle and obtain the position information of the unmanned aerial vehicle at this time as the initial position data, and use the image acquisition device carried on the unmanned aerial vehicle to obtain an image of the target wind turbine;

[0008] Based on the image of the target wind turbine, identify the angle data of each blade of the current target wind turbine with respect to the vertical direction;

[0009] According to the initial position data of the unmanned aerial vehicle, the angle data of each blade of the target wind turbine with respect to the vertical direction, and the parameter data of the blade, calculate the position data of each blade of the target wind turbine;

[0010] Plan the inspection path of the UAV based on the position data of each blade of the target wind turbine generator and the initial position data of the UAV, and make the UAV fly along the inspection path.

[0011] As a preferred implementation manner, the method for identifying the angle data between each blade of the current target wind turbine generator and the vertical direction based on the blade image of the target wind turbine generator is specifically as follows:

[0012] Perform a grayscale operation on the blade image of the target wind turbine generator to obtain a grayscale image;

[0013] Perform an edge operation on the grayscale image to filter the background of the image and obtain the object contour in the image;

[0014] Perform a rectangular shape acquisition operation to obtain all rectangular targets in the image;

[0015] Perform a morphological dilation operation on all the obtained rectangular targets and the image of the original target wind turbine generator, and perform a NOT operation on the image of the original target wind turbine generator based on the dilated rectangular targets to obtain an image to be recognized;

[0016] Perform contour detection on the image to be recognized, and preliminarily screen the contours whose size ratios meet the preset conditions;

[0017] Search for the contours with a 120-degree difference in the contour center line angles among the preliminarily screened contours as the blade contour set;

[0018] Obtain the angle between each blade contour in the blade contour set and the vertical direction.

[0019] As a preferred implementation manner, in the step of obtaining the position information of the UAV at this time as the initial position data:

[0020] The position information of the UAV at this time includes the current longitude and latitude data of the UAV, the current orientation data, and the current height data relative to the starting ground.

[0021] As a preferred implementation manner, the step of calculating the position data of each blade of the target wind turbine generator according to the initial position data of the UAV, the angle data between each blade of the target wind turbine generator and the vertical direction, and the parameter data of the blade is specifically as follows:

[0022] Take the current longitude and latitude data, the current orientation data, and the current height data relative to the starting ground of the UAV as the starting point;

[0023] Through the angle data between each blade and the vertical direction and the length data of the blade, calculate the offset distance between the tip of each blade and the starting point through the trigonometric sine function and the trigonometric cosine function;

[0024] According to the offset distance between the tip of each blade and the starting point, calculate the longitude and latitude data of the tip of each blade through the longitude and latitude direction angle and distance calculation formula.

[0025] As a preferred embodiment, the step of planning the inspection path of the unmanned aerial vehicle based on the position data of each blade of the target wind turbine generator and the initial position data of the unmanned aerial vehicle, and making the unmanned aerial vehicle fly along the inspection path is specifically as follows:

[0026] Calculate an inspection path based on the current longitude and latitude data of the unmanned aerial vehicle, the current orientation data of the unmanned aerial vehicle, the current height data of the unmanned aerial vehicle relative to the starting ground, the distance data between the unmanned aerial vehicle and the hub center of the wind turbine generator, and the longitude and latitude data of the tip of each blade.

[0027] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the method for planning the inspection path of the blades of a wind turbine generator based on an unmanned aerial vehicle as described in any embodiment of the present invention when executing the program.

[0028] On another aspect, the present invention also provides a computer-readable storage medium, on which a computer program is stored, wherein the program implements the method for planning the inspection path of the blades of a wind turbine generator based on an unmanned aerial vehicle as described in any embodiment of the present invention when executed by a processor.

[0029] The present invention has the following beneficial effects:

[0030] 1. The method for planning the inspection path of the blades of a wind turbine generator based on an unmanned aerial vehicle according to the present invention uses the unmanned aerial vehicle to inspect the blades of the wind turbine generator, and can identify the angle data between each blade of the wind turbine generator and the vertical direction in real time. Based on the angle data, the path is planned, so that the fan blades can stop at any angle during the inspection process, and the inspection efficiency is high.

[0031] 2. The method for planning the inspection path of the blades of a wind turbine generator based on an unmanned aerial vehicle according to the present invention proposes a method for identifying the angle between each blade of the wind turbine generator and the vertical direction, which can quickly identify the blade contour in the image and accurately calculate the angle between the blade and the vertical direction based on the blade contour. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flowchart of the method according to an embodiment of the present invention;

[0033] Figure 2 is an example diagram for identifying the angle data between each blade and the vertical direction in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] It should be understood that the step numbers used in the text are only for convenient description and do not limit the execution order of the steps.

[0036] It should be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0037] The terms "comprising" and "including" indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their combinations.

[0038] The term " / or" refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0039] Embodiment 1:

[0040] See Figure 1 , a method for planning an inspection path of a wind turbine blade based on an unmanned aerial vehicle, comprising the following steps:

[0041] Control the unmanned aerial vehicle and obtain the position information of the unmanned aerial vehicle at this time as the initial position data, and use the image acquisition device carried on the unmanned aerial vehicle to obtain an image of the target wind turbine

[0042] The staff remotely controls the unmanned aerial vehicle to fly near the hub of the target wind turbine, facing the center of the hub, adjusts the distance from the center of the hub through the laser rangefinder carried on the unmanned aerial vehicle, and judges whether the specified distance (such as 15 meters) is reached. If it is reached, the unmanned aerial vehicle is hovered and the position information of the unmanned aerial vehicle at this time is obtained by using the RTK high-precision positioning module carried on the unmanned aerial vehicle as the initial position data, and the blade image of the current target wind turbine is obtained by using the image acquisition device carried on the unmanned aerial vehicle. In this embodiment, the image acquisition device is a pan-tilt camera;

[0043] Identify the included angle angle data between each blade of the current target wind turbine and the vertical direction through the image of the target wind turbine, so as to obtain the included angle angle data between each blade and the column of the wind turbine.

[0044] Calculate the position data of each blade of the target wind turbine based on the initial position data of the UAV, the distance information between the UAV and the target wind turbine, the angle data of each blade of the target wind turbine with respect to the vertical direction, and the parameter data of the blade.

[0045] Plan the inspection path of the UAV based on the position data of each blade of the target wind turbine and the initial position data of the UAV, and make the UAV fly along the inspection path.

[0046] As a preferred implementation manner of this embodiment, the step of identifying the angle data of each blade of the current target wind turbine with respect to the vertical direction based on the blade image of the target wind turbine is implemented based on the OpenCV model. The specific method is as follows:

[0047] Perform a grayscale operation on the blade image of the target wind turbine to obtain a grayscale image.

[0048] Perform an edge operation on the grayscale image to filter the background of the grayscale image and obtain the object contour in the grayscale image.

[0049] See Figure 2 , use the plug-in of OpenCV to perform a rectangular shape acquisition operation to obtain all rectangular targets in the image.

[0050] Perform a morphological dilation operation on all the obtained rectangular targets and the original blade image of the target wind turbine, and perform a bitwise NOT operation on the original blade image of the target wind turbine based on the dilated rectangular targets to obtain an image to be recognized.

[0051] Use the plug-in of OpenCV to perform contour detection on the image to be recognized, and initially screen the contours whose size ratios meet the preset conditions.

[0052] Find the contours with a 120-degree difference in the contour center line angles among the initially screened contours as the blade contour set, where the contour center line refers to the center line parallel to the length direction of the rectangular contour.

[0053] Based on the position data of the target boxes of each blade contour in the blade contour set, the angle of each blade contour with respect to the vertical direction can be calculated.

[0054] As a preferred implementation manner of this embodiment, in the step of obtaining the position information of the UAV at this time as the initial position data:

[0055] The position information of the UAV at this time includes the current latitude and longitude data of the UAV (such as 112.13, 30.12), the current orientation data of the UAV (such as 45°), and the current height data relative to the starting ground (such as 90 meters).

[0056] As a preferred embodiment, the step of measuring the distance information between the drone and the hub center of the target wind turbine by using the laser ranging device carried on the drone is specifically as follows:

[0057] Control the emitted light of the laser ranging device to hit the hub of the wind turbine to obtain the relative distance between the drone and the hub center.

[0058] As a preferred embodiment of this embodiment, the step of calculating the position data of each blade of the target wind turbine according to the initial position data of the drone, the angle data of each blade of the target wind turbine with respect to the vertical direction, and the parameter data of the blade is specifically as follows:

[0059] Use the current longitude and latitude data (112.13, 30.12), the current orientation data of the drone (45°), and the current height data relative to the starting ground (90 meters) as the starting point;

[0060] Based on the angle data of each blade with respect to the vertical direction (such as 75° for blade No. 1, 195° for blade No. 2, and 315° for blade No. 3) and the pre-input blade side length data, calculate the vertical (height) and horizontal (the direction the drone is currently facing) offset distances of the tip of each blade from the starting point through the sine and cosine functions of trigonometry; specifically:

[0061] Take the length of the blade as the hypotenuse of a right triangle and the angle between the blade and the vertical direction as angle α. Given the hypotenuse of a right triangle and an angle α, then:

[0062] Opposite side = sinα * hypotenuse

[0063] Adjacent side = cosα * hypotenuse

[0064] Given the right side opposite the right angle of a right triangle and an angle α, then:

[0065] Hypotenuse = opposite side / sinα

[0066] Adjacent side = cosα * (opposite side / sinα)

[0067] Given the right side adjacent to the right angle of a right triangle and an angle α, then:

[0068] Hypotenuse = adjacent side / cosα

[0069] Opposite side = sinα * (adjacent side / cosα)

[0070] According to the function formula, calculate the horizontal and vertical movement distances of the blade tip corresponding to the starting position through the blade angle and blade length. In this embodiment:

[0071] Offset distance of the tip of blade No. 1: Move 48.2963 to the left: height - 12.941;

[0072] Tip offset distance of blade No. 2: shifted left by -12.941: height 48.2963;

[0073] Tip offset distance of blade No. 3: shifted left by -35.3553: height -35.3553;

[0074] Given the data of the starting point, according to the offset distances between the tips of each blade and the starting point, through the longitude and latitude direction angle and distance calculation formula, calculate the longitude and latitude data of the tips of each blade:

[0075] Specifically: Obtain the longitude and latitude data of the starting point position, the offset distance data of each tip, and the direction angle data (the angle from the due north to the target point), then for any tip:

[0076] Latitude: φ2 = asin(sinφ1⋅cosδ + cosφ1⋅sinδ⋅cosθ);

[0077] Longitude: λ2 = λ1 + atan2(sinθ⋅sinδ⋅cosφ1, cosδ - sinφ1⋅sinφ2);

[0078] The longitude and latitude in the above formula need to be converted to radians. Among them: λ2 is the resulting longitude, λ1 is the starting longitude, φ2 is the resulting latitude, φ1 is the starting latitude, θ is the direction angle, R is the radius of the earth, δ represents the angular distance, that is, d / R, and d is the distance (km);

[0079] In this embodiment, the longitude and latitude data of each tip are:

[0080] Longitude and latitude data of the tip of blade No. 1: 112.12964533, 30.11969321;

[0081] Longitude and latitude data of the tip of blade No. 2: 112.13009503, 30.12008220;

[0082] Longitude and latitude data of the tip of blade No. 3: 112.13025963, 30.12022457.

[0083] As a preferred implementation manner of this embodiment, the step of planning the inspection path of the unmanned aerial vehicle based on the position data of each blade of the target wind turbine generator and the initial position data of the unmanned aerial vehicle, and making the unmanned aerial vehicle fly along the inspection path is specifically as follows:

[0084] Determine the data of the starting point based on the current latitude and longitude data of the UAV, the current orientation data of the UAV, and the height data of the UAV relative to the starting ground. Calculate the latitude and longitude data of the wind turbine hub based on the distance data between the UAV and the wind turbine hub. After knowing the data of the starting point, the latitude and longitude data of the wind turbine hub, and the latitude and longitude data of the tips of each blade, calculate the latitude and longitude data on the left, right, and back sides of each blade according to the azimuth angle and distance of the latitude and longitude; generate an inspection path from the calculated latitude and longitude data of each path point in a specified order.

[0085] In this embodiment, the inspection path is specifically as follows:

[0086] Front of the hub center -> Front of the tip of blade 1 -> Left side of the tip of blade 1 -> Left side of the hub center -> Back side of the hub center -> Back side of the tip of blade 1 -> Right side of the tip of blade 1 -> Right side of the hub center;

[0087] Front of the hub center -> Front of the tip of blade 2 -> Left side of the tip of blade 2 -> Left side of the hub center -> Back side of the hub center -> Back side of the tip of blade 2 -> Right side of the tip of blade 2 -> Right side of the hub center;

[0088] Front of the hub center -> Front of the tip of blade 3 -> Left side of the tip of blade 3 -> Left side of the hub center -> Back side of the hub center -> Back side of the tip of blade 3 -> Right side of the tip of blade 3 -> Right side of the hub center;

[0089] Embodiment 2:

[0090] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein when the processor executes the program, it implements the method for planning an inspection path of a wind turbine blade based on a UAV as described in any embodiment of the present invention.

[0091] Embodiment 3:

[0092] The present invention also provides a computer-readable storage medium, on which a computer program is stored, wherein when the program is executed by a processor, it implements the method for planning an inspection path of a wind turbine blade based on a UAV as described in any embodiment of the present invention.

[0093] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent the situations of A existing alone, A and B existing simultaneously, and B existing alone. Here, A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one of the following" and its similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0094] Those of ordinary skill in the art can realize that the various units and algorithm steps described in the embodiments disclosed herein can be implemented by a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present application.

[0095] In several embodiments provided by the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (hereinafter referred to as ROM), random access memories (hereinafter referred to as RAM), magnetic disks, or optical discs that can store program codes.

[0096] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for planning an inspection path for the blades of a wind turbine based on an unmanned aerial vehicle, characterized in that, it includes the following steps: Control the unmanned aerial vehicle to fly near the hub of the target wind turbine, facing the center of the hub, adjust the distance from the center of the hub through the laser rangefinder carried on the unmanned aerial vehicle, hover the unmanned aerial vehicle and obtain the position information of the unmanned aerial vehicle at this time as the initial position data, and use the image acquisition device carried on the unmanned aerial vehicle to obtain the blade images of the target wind turbine; Based on the blade images of the target wind turbine, identify the angle data of each blade of the current target wind turbine with respect to the vertical direction; According to the initial position data of the unmanned aerial vehicle, the angle data of each blade of the target wind turbine with respect to the vertical direction, and the parameter data of the blades, calculate the position data of each blade of the target wind turbine; Based on the position data of each blade of the target wind turbine and the initial position data of the unmanned aerial vehicle, plan the inspection path of the blades of the unmanned aerial vehicle; The method for identifying the angle data of each blade of the current target wind turbine with respect to the vertical direction based on the blade images of the target wind turbine is specifically as follows: Perform a grayscale operation on the blade images of the target wind turbine to obtain a grayscale image; Perform an edge operation on the grayscale image to filter the background of the image and obtain the object contour in the image; Perform a rectangular shape acquisition operation to obtain all rectangular targets in the image; Perform a morphological dilation operation on all the obtained rectangular targets and the original blade images of the target wind turbine, and perform a NOT operation on the original image of the target wind turbine based on the dilated rectangular targets to obtain an image to be recognized; Perform contour detection on the image to be recognized and preliminarily screen the contours whose size ratios meet the preset conditions; Find the contours with a 120-degree difference in the contour center line angles among the preliminarily screened contours as the blade contour set; Obtain the angle of each blade contour in the blade contour set with respect to the vertical direction; In the step of obtaining the position information of the unmanned aerial vehicle at this time as the initial position data: The position information of the unmanned aerial vehicle at this time includes the current longitude and latitude data, the current orientation data, and the current height data relative to the starting ground; The step of calculating the position data of each blade of the target wind turbine according to the initial position data of the unmanned aerial vehicle, the angle data of each blade of the target wind turbine with respect to the vertical direction, and the parameter data of the blades is specifically as follows: Use the current longitude and latitude data, the current orientation data, and the current height data relative to the starting ground of the unmanned aerial vehicle as the starting point; Through the angle data of each blade with respect to the vertical direction and the length data of the blades, calculate the offset distance from the tip of each blade to the starting point through the sine function and cosine function of the triangle; According to the offset distance from the tip of each blade to the starting point, calculate the longitude and latitude data of the tip of each blade through the longitude and latitude direction angle and distance calculation formula.

2. The method for planning an inspection path for the blades of a wind turbine based on an unmanned aerial vehicle according to claim 1, characterized in that, The step of planning the inspection path of the unmanned aerial vehicle based on the position data of each blade of the target wind turbine and the initial position data of the unmanned aerial vehicle, and making the unmanned aerial vehicle fly along the inspection path is specifically as follows: Calculate an inspection path based on the current latitude and longitude data of the drone, the current orientation data of the drone, the current height data of the drone relative to the starting ground, the distance data between the drone and the hub center of the wind turbine generator, and the latitude and longitude data of the tips of each blade.

3. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, when the processor executes the program, it implements the method for planning an inspection path of the blades of a wind turbine generator based on a drone as described in any one of claims 1 to 2.

4. A computer-readable storage medium, on which a computer program is stored, wherein, when the program is executed by the processor, it implements the method for planning an inspection path of the blades of a wind turbine generator based on a drone as described in any one of claims 1 to 2.

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