Fan autonomous inspection strategy based on multidirectional viewpoint planning

Abstract

The invention discloses a fan autonomous inspection strategy based on multidirectional viewpoint planning, and relates to the technical field of robot inspection, first, three inspection waypoints are designed based on known fan yaw and blade tip coordinates, and an inspection waypoint calculation method combining unmanned aerial vehicle constraint and holder elevation angle constraint is given; then, performing multidirectional viewpoint planning and zoom planning at the inspection waypoint, namely generating a plurality of viewpoint directions capable of covering the blade at the inspection waypoint, and resolving the focal length according to the distance, so that the blade in the image occupies a certain proportion, and the image quality is ensured; and finally, two transition waypoints are used for enabling the unmanned aerial vehicle to bypass the blades between the inspection waypoints, and the inspection waypoints and the transition points are sequentially connected to form an inspection path. Compared with a method for routing inspection along the fixed focus of the blade, the method has the advantages that the number of waypoints can be greatly reduced, the routing inspection time is shortened by more than 30% and the routing inspection path length is shortened by more than 15% for the blades with different postures.

Description

Technical Field

[0001] The present invention relates to the technical field of robot inspection, and in particular to an autonomous inspection strategy for wind turbines based on multi-directional viewpoint planning. Background Art

[0002] In the field of robot inspection, wind turbine blade inspection is extremely important. Most traditional wind turbine blade inspection methods use one-way waypoints, that is, the gimbal has only one movement or one shooting angle at a waypoint, and fails to fully utilize the gimbal and zoom functions of the drone. This method leads to a large number of waypoints and low inspection efficiency. Although the pilot can operate the gimbal to take photos at different angles at a waypoint when manually flying a drone to inspect the wind turbine, the application of multi-directional waypoints in the current autonomous inspection scheme is relatively rare. With the development of technology, the requirements for the efficiency and accuracy of autonomous inspection of wind turbines are constantly increasing. There is an urgent need for a wind turbine blade inspection method that can give full play to the gimbal and zoom functions of drones, reduce the number of waypoints, and improve inspection efficiency.

[0003] In view of this, this application is hereby filed. Summary of the invention

[0004] The object of the present invention is to provide a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning to solve the problem of long inspection time of existing wind turbine blades mentioned in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides an autonomous inspection strategy for wind turbines based on multi-directional viewpoint planning, comprising the following steps: S1: According to the hub coordinates and blade tip coordinates of the wind turbine, the blade tips are classified into upper blade tips, equal-height blade tips and lower blade tips according to their height relationship with the hub, and the symmetrical point of the blade tip on the wind wheel circle about the hub is used as the basic reference point. Three inspection waypoints are set for different blade tip combinations, wherein the orientation of two adjacent blade surfaces is determined by the positions of the two blade tips. The specific waypoint setting strategy is: when there are two upper blade tips, When there are two lower blade tips, the symmetrical point of another blade tip on the rotor plane about the hub is used as the waypoint for inspecting the two corresponding blade surfaces; when there are two lower blade tips, the waypoint is on the vertical line passing through the reference point and perpendicular to the rotor plane. The distance from the waypoint to the plane is determined by the maximum elevation angle of the drone gimbal, and the hub is used as the corresponding point of the maximum gimbal elevation angle to calculate the waypoint position; when there is an upper blade tip and a lower blade tip, a second reference point is introduced, which is located on the rotor circle and is the corresponding point of the maximum gimbal elevation angle obliquely below the upper blade tip. The higher of the two reference points is taken as Waypoints; S2: viewpoint planning is performed at each inspection waypoint, and an interpolation point is generated on the blade. One interpolation point corresponds to one viewpoint, and the viewpoint direction is from the waypoint to the interpolation point. The interpolation point can be set by using a fixed number of equidistant interpolation points or by setting the interpolation points according to the camera field of view and distance information, and the focal length of each viewpoint is calculated according to the distance from the waypoint to the interpolation point to ensure that the blade occupies a certain proportion in the image; S3: two transition waypoints are set, and the blade tips are arranged from the lower blade tip to the upper blade tip along the counterclockwise direction of the wind wheel sweep circle in the front view of the wind turbine. Based on the order of the three inspection waypoints, the coordinates of the first transition point are composed of the z coordinate of the first waypoint and the xy coordinates of the second waypoint, so that the drone first rises in height and then moves to the second waypoint. The height of the second transition point is higher than the third blade tip and the xy coordinates are the same as the third blade tip, so that the drone bypasses the third blade tip and flies to the third waypoint; S4: the waypoints and transition points are connected with straight lines in sequence to obtain the inspection route, so that the drone inspects the wind turbine according to the route and returns to the take-off point after the inspection is completed.

[0006] Furthermore, the calculation of the interpolation points, if the interpolation points are set according to the camera field of view and distance information, the camera field of view includes the horizontal field of view and the vertical field of view, the smaller field of view is used to calculate the number of interpolation points, and the shortest distance from the waypoint to the blade is d min , the field of view length is l, the field of view angle is β, the blade length is R, the number of interpolation points on the blade is n, n is an integer and satisfies the relevant calculation formula.

[0007] Furthermore, the focal length is calculated based on the principle of similar triangles, taking the average width of the blade as X, 1 / 3 of the image width as X, the distance from the waypoint to the interpolation point as d, and the focal length of the camera as f

[0008] , satisfying the relevant calculation formula to ensure that the focal length corresponding to each viewpoint makes the leaves occupy a certain proportion in the image.

[0009] Furthermore, when calculating the waypoint coordinates when there is an upper blade tip and a lower blade tip, a specific set of equations must be satisfied, and the waypoint coordinates are calculated by obtaining relevant parameters by solving the set of equations.

[0010] Furthermore, the three inspection waypoints and two transition waypoints, a total of five waypoints, complete the wind turbine blade inspection, thereby minimizing the number of drone waypoints in the wind turbine inspection.

[0011] Furthermore, the process of the drone inspecting the wind turbine does not require human intervention, thus achieving autonomous inspection of the wind turbine.

[0012] Furthermore, the setting of inspection waypoints, viewpoint planning, focal length calculation and setting of transition waypoints are all based on full utilization of the drone gimbal and camera focal length to reduce the number of wind turbine inspection waypoints.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. Significant waypoint optimization effect: The present invention uses a unique three-inspection waypoint setting strategy to complete the wind turbine blade inspection using only five waypoints (three inspection waypoints and two transition waypoints). Compared with the traditional fixed-focus inspection method along the blade, the number of waypoints is greatly reduced. Experimental verification shows that the inspection path length is shortened by more than 15%, effectively reducing the flight energy consumption and inspection cost of the drone and improving the inspection efficiency.

[0015] 2. Autonomous and efficient inspection: This method is applied to autonomous inspection of wind turbines without manual intervention. During the inspection process, based on the effective combination of wind turbine hub and blade tip coordinates and the drone gimbal and camera focal length, the inspection waypoints, viewpoints and focal lengths are automatically planned, and transition waypoints are set to form a safe inspection path. The entire process is completely autonomous, saving labor costs, while improving the stability and reliability of the inspection, and can adapt to wind turbine inspection tasks under different working conditions;

[0016] 3. Image quality assurance: A multi-directional viewpoint planning strategy is adopted to perform viewpoint planning and focal length calculation at the inspection waypoints. By reasonably setting interpolation points on the blades and accurately calculating the focal length based on the distance from the waypoints to the interpolation points, it is ensured that the blades occupy a certain proportion in the image, thereby ensuring the quality of the captured image. High-quality images help to more accurately detect the status of wind turbine blades, discover potential problems in a timely manner, and provide strong support for the maintenance and safe operation of wind turbines;

[0017] 4. Inspection time is greatly shortened: Experiments show that compared with traditional inspection methods, the present invention shortens the inspection time for blades in different postures by more than 30%. This is due to the reduction in the number of waypoints and the application of multi-directional viewpoint planning strategies. The drone does not need to frequently adjust the route and shooting angle during the inspection process, and can complete the comprehensive inspection of the wind turbine blades more quickly, improving the timeliness of wind turbine inspections and reducing the impact on the normal operation of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a principle block diagram of a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning;

[0019] Figure 2 A route generation flowchart (left) and drone inspection flowchart (right) for an autonomous wind turbine inspection strategy based on multi-directional viewpoint planning.

[0020] Figure 3 The diagram is a schematic diagram of two inspection methods in a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning;

[0021] Figure 4 This is a multi-viewpoint planning flow chart for a wind turbine autonomous inspection strategy based on multi-viewpoint planning.

[0022] Figure 5 A schematic diagram of a wind turbine front view in a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning;

[0023] Figure 6 Schematic diagram of the front and side views of a wind turbine in an autonomous inspection strategy for wind turbines based on multi-directional viewpoint planning;

[0024] Figure 7 This is a principle block diagram of the wind turbine front view geometric relationship diagram in a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning;

[0025] Figure 8 A schematic diagram of the camera field of view in a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning;

[0026] Fig. 9 A schematic diagram of a camera projection model in a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning;

[0027] Fig.10 Schematic diagram of the inspection path in a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1 -

[0030] Fig.10 The present invention provides a technical solution: a wind turbine autonomous inspection strategy based on multi-directional viewpoint planning, comprising:

[0031] 1. Overall analysis:

[0032] For wind turbines with unknown postures in real wind farms, the first thing to do is to obtain wind turbine related parameters, such as wind turbine yaw and blade tip coordinates. Many researchers have done work on obtaining wind turbine yaw and blade tip position. For stationary wind turbines, the present invention designs a wind turbine inspection strategy using multi-directional viewpoint planning based on the known hub and blade tip coordinates. The present invention intends to design three inspection waypoints to collect images of wind turbine blades, and then add transition points to design the overall inspection route. Among them, multi-directional viewpoint planning is to execute multiple drone actions and gimbal actions at a waypoint position to complete the shooting of multiple blades at one waypoint.

[0033] The static wind turbine is in the pulping state, that is, the blades are perpendicular to the rotor plane. To simplify, there are a total of six surfaces of the three blades that need to be inspected. Three inspection waypoints are designed in the rotor plane with the symmetrical point of the blade tip about the hub as the reference point. For the upward blade surface, the waypoint is designed in the rotor plane; for the downward blade surface, due to the attitude restriction of the drone and the gimbal angle restriction, the waypoint is designed outside the rotor plane. Each waypoint shoots two blade surfaces, and three waypoints are designed to cover six surfaces. After obtaining the waypoints, viewpoint planning is performed for each waypoint, that is, under the premise that the position of the waypoint remains unchanged, the multi-directional waypoint is realized by changing the yaw angle of the drone and the pitch angle of the gimbal. Specifically, interpolation points are set on the blades, and one interpolation point corresponds to one viewpoint, that is, one shooting point. In addition, the distance from each interpolation point to the waypoint is different, and the imaging is clear through zooming to ensure image quality. The setting of interpolation points can set a fixed number of equidistant interpolation points, or set interpolation points according to the size of the camera field of view. In simple terms, the drone looks at the interpolation points of the two blades in turn from one waypoint to achieve image acquisition of the two blade surfaces. Two transition points are set among the three waypoints so that the drone can fly around the blades to the next inspection waypoint to avoid colliding with the wind turbine. A straight line is used to connect the inspection waypoints and transition points in sequence to form a route. The drone takes off and flies along the route. After the inspection is completed, it returns to the take-off point (refer to Figure 2 shown).

[0034] Reference Figure 3 As shown in the figure, there are two inspection methods. Figure 3 (a) is a schematic diagram of the commonly used fixed focus inspection along the blade. Figure 3 (b) is a schematic diagram of the inspection waypoints of the present invention (multi-directional viewpoint planning inspection). The former is to inspect along the wind turbine blades with a fixed PTZ and focal length, such as Figure 3 (a),This method generates flight paths parallel to the blade on both sides of the blade and collects images at a fixed distance. Figure 3 The dot in (a) is a waypoint. The latter is an inspection method based on multi-directional viewpoint planning of the present invention, in which the pan / tilt and zoom are adjusted at the waypoint to realize blade inspection. Figure 3 In (b), the short and large arrows are waypoints, the arrow direction represents the approximate orientation of the drone, the dotted arrow is the viewpoint direction, and the dots are the shooting points (interpolation points) on the blade.

[0035] 2. Multi-directional viewpoint planning and inspection path:

[0036] This section describes the waypoint positions and the final path in steps, which is the wind turbine autonomous inspection strategy based on multi-directional viewpoint planning of the present invention. A total of six surfaces of three blades need to be inspected. The overall idea of ​​multi-directional viewpoint planning is to obtain three waypoints, and use one waypoint to inspect the two adjacent blade surfaces between the two blade tips. After that, interpolation points are generated on the blades, multiple viewpoint directions of a single waypoint are set, and the appropriate focal length is calculated based on the distance between the waypoint and the interpolation point to achieve zooming in different viewpoint directions. Finally, a transition point is set to allow the drone to bypass the wind turbine and fly to the next waypoint. A straight line connects the inspection waypoints and transition points to obtain the final inspection path (refer to Figure 4 ).

[0037] 2.1 Obtaining inspection waypoints:

[0038] The orientation of two adjacent blade surfaces is determined by the position of the two blade tips. The blade tip can be divided into an upper blade tip, an equal-height blade tip and a lower blade tip according to its height relationship with the hub. The equal-height blade tip indicates the existence of a horizontally placed blade. In order to facilitate the calculation of waypoints, the equal-height blade tip is regarded as the lower blade tip. In addition, the symmetrical point of the blade tip about the hub on the wind rotor plane is set as a reference point for calculating the waypoint. The positional relationship between the two blade tips is different, and the inspection waypoint position is also different. A classified discussion is conducted below to give the waypoint setting strategy of the present invention. A world coordinate system is established with the take-off point of the drone as the origin, with the z-axis pointing vertically upward, pointing to the sky.

[0039] (1) Two upper blade tips: directly use the reference point, that is, the symmetrical point of the other blade tip on the rotor plane with respect to the hub as the waypoint. Figure 5, B1, B2, B3 are blade tips, o is the wheel hub, Q is the reference point, and H is the waypoint. B2 and B3 are both upper blade tips, and the symmetrical point Q of another blade tip B1 is used as the waypoint H for inspecting the two blade surfaces between B2 and B3 (refer to Figure 5 ).

[0040] (2) Two lower blade tips: Due to the attitude constraints of the UAV and the limitation of the gimbal, the waypoint needs to be selected outside the wind rotor plane. The waypoint is on the vertical line passing through the reference point and perpendicular to the wind rotor plane. The distance from the waypoint to the plane is determined by the maximum elevation angle of the UAV gimbal. When there are two lower blade tips, the highest point of the two middle blades is the hub. The hub is used as the corresponding point of the maximum elevation angle of the gimbal to calculate the waypoint position. Figure 6 , the left side is the front view of the wind rotor plane, and the right side is the side view of the wind rotor plane. o is the hub, with coordinates (x0, y0, z0), B1, B2, B3 are three blade tips, of which B1 and B2 are the lower blade tips, B3 is the upper blade tip, and the coordinates of B3 are (x3, y3, z3), Q is the reference point, H is the waypoint, with coordinates (x, y, z), and d is the distance from the waypoint to the wind rotor plane. In addition, the maximum elevation angle of the gimbal is α.

[0041]

[0042] The horizontal and vertical coordinates of the waypoint H can be calculated based on the wind turbine yaw and d.

[0043] (3) One upper blade tip and one lower blade tip: Considering the limit of the turret elevation angle, a second reference point is introduced. Located on the wind rotor circle, it is the corresponding point of the maximum turret elevation angle below the upper blade tip. The first reference point is the symmetrical point of the other blade tip about the hub on the wind rotor plane. The higher of the two reference points is taken as the waypoint. Figure 6 , o is the wheel hub, with coordinates (x0, y0, z0), B1, B2, B3 are three blade tips, of which B1 and B2 are lower blade tips, B3 is upper blade tip, and the coordinates of B3 are (x3, y3, z3), Q1 is the first reference point, Q2 is the first reference point, H is the waypoint, with coordinates (x, y, z), d1 is the distance from Q2 to the upper blade tip on the xy plane. In addition, the maximum elevation angle of the gimbal is α.

[0044] For blade tips B3 and B1, the waypoint is selected as Q2. The following relationship is satisfied:

[0045]

[0046] Solving equation group (2-2) can obtain d1 and z, and then the coordinates of H can be obtained from the relationship between H and B3.

[0047] For blade tips B2 and B3, the waypoint is selected as Q1;

[0048]

[0049] 2.2 Viewpoint Planning:

[0050] A waypoint needs to inspect two blade surfaces between two blade tips. Viewpoint planning needs to be performed at the waypoint to generate enough viewpoints to cover the two blade surfaces. First, equidistant interpolation points are generated on the blade. One interpolation point corresponds to one viewpoint, and the viewpoint direction is from the waypoint to the interpolation point. In order to ensure the image quality, focal length calculation is required to obtain the focal length suitable for each viewpoint.

[0051] (1) Interpolation point calculation:

[0052] The interpolation points can be set to a fixed number of equally spaced interpolation points, or to set interpolation points based on the camera field of view and distance information, i.e. the camera field of view. The camera field of view includes the horizontal field of view and the vertical field of view. The smaller field of view is used to calculate the number of interpolation points. Figure 8 , d min

[0053] is the shortest distance from the waypoint to the blade, l is the field of view length, β is the field of view angle, and the blade length is R

[0054] , the number of interpolation points on the leaf is n, n is an integer (refer to Figure 8 ).

[0055]

[0056] (2) Focal length calculation:

[0057] The focal length of each viewpoint is calculated based on the distance from the waypoint to the interpolated point. Fig. 9 is the projection model of the camera, f is the focal length of the camera, X is the actual size of the object, X' is the pixel size of the object, and d

[0058] is the object distance, i.e. the distance from the waypoint to the interpolation point (refer to Fig. 9 ).

[0059] According to the principle of similar triangles, we have the following relationship:

[0060]

[0061] Where X is the average width of the leaves. The goal is to have leaves occupy a certain size in the image, X'

[0062] Take 1 / 3 of the image width. Each viewpoint has a corresponding focal length to ensure that the leaves occupy a certain proportion in the image.

[0063] 2.3 Inspection path:

[0064] Inspection waypoints are designed, and viewpoint planning and focal length calculation are performed for each waypoint. Next, transition points are designed to bypass the wind turbine and fly safely to the next inspection waypoint, and then the overall inspection path is designed. The design of the transition point relies on the three designed inspection waypoints. One transition point is inserted between two adjacent waypoints, and two transition points need to be inserted into the three waypoints. Arrange the blade tips from the lower blade tip to the upper blade tip along the counterclockwise direction of the wind wheel sweep circle in the front view of the wind turbine. Therefore, the obtained waypoints also have a corresponding order. One waypoint inspects the two blade surfaces between the two blade tips. Therefore, there is a blade between the two waypoints. The purpose of designing the transition point is to bypass the blade between the two waypoints. Because of the sequentiality of the three waypoints, from the front view of the wind turbine, the direction from the first waypoint to the second waypoint is from bottom to top, and the direction from the second waypoint to the third waypoint is from left to right. The coordinates of the first transition point are composed of the z coordinate of the first waypoint and the xy coordinates of the second waypoint. The first transition point allows the drone to rise in height first and then move to the second waypoint. The second transition point is higher than the third blade tip, and its xy coordinates are the same as those of the third blade tip. The second transition point causes the drone to fly around the third blade tip to the third waypoint.

[0065] Connect the waypoints and transition points with straight lines to obtain the inspection route. Fig.10 As shown, the circular points are inspection waypoints and the triangular points are transition waypoints.

[0066] In summary: the present invention proposes an innovative method for UAV inspection of wind turbines. By making full use of the UAV gimbal and camera focal length, the three-inspection waypoint setting strategy based on the coordinates of the wind turbine hub and blade tip, the intermediate transition point setting strategy, and the multi-directional viewpoint planning strategy, the method achieves the minimization of wind turbine inspection waypoints, autonomous and efficient inspection, image quality assurance, and a significant reduction in inspection time. This method provides a feasible and efficient solution for the field of autonomous wind turbine inspection, which helps to promote the further development of wind turbine inspection technology.

Claims

1. A wind turbine autonomous inspection strategy based on multi-directional viewpoint planning, characterized by: The following steps are involved: S1: According to the hub coordinates and blade tip coordinates of the wind turbine, the blade tips are classified into upper blade tips, equal-height blade tips and lower blade tips according to their height relationship with the hub. The symmetric point of the blade tip on the rotor circle about the hub is used as the basic reference point. Three inspection waypoints are set for different blade tip combinations. The orientation of two adjacent blade surfaces is determined by the positions of the two blade tips. The specific waypoint setting strategy is as follows: When there are two upper blade tips, the symmetrical point of the other blade tip on the rotor plane about the hub is used as the waypoint for inspecting the corresponding two blade surfaces; When there are two lower blade tips, the waypoint is on the vertical line passing through the reference point and perpendicular to the wind rotor plane. The distance from the waypoint to the plane is determined by the maximum elevation angle of the drone gimbal, and the waypoint position is calculated with the wheel hub as the corresponding point of the maximum elevation angle of the gimbal; When there is an upper blade tip and a lower blade tip, introduce a second reference point located on the wind rotor circle, which is the corresponding point of the maximum pan / tilt angle obliquely below the upper blade tip. The higher of the two reference points is taken as the waypoint. S2: Perform viewpoint planning at each inspection waypoint and generate interpolation points on the blade. One interpolation point corresponds to one viewpoint. The viewpoint direction is from the waypoint to the interpolation point. The interpolation points can be set by using a fixed number of equidistant interpolation points or by setting interpolation points according to the camera field of view and distance information. The focal length of each viewpoint is calculated according to the distance from the waypoint to the interpolation point to ensure that the blade occupies a certain proportion in the image. S3: Set two transition waypoints, and arrange the blade tips from the lower blade tip to the upper blade tip along the counterclockwise direction of the wind rotor sweep circle in the front view of the wind turbine. Based on the order of the three inspection waypoints, the coordinates of the first transition point are composed of the z coordinate of the first waypoint and the xy coordinates of the second waypoint, so that the drone first rises in height and then moves to the second waypoint. The height of the second transition point is higher than the third blade tip and the xy coordinates are the same as the third blade tip, so that the drone flies around the third blade tip to the third waypoint; S4: Connect the waypoints and transition points with straight lines in sequence to obtain an inspection route, so that the UAV inspects the wind turbine along the route and returns to the take-off point after the inspection is completed.

2. The wind turbine autonomous inspection strategy based on multi-directional viewpoint planning as claimed in claim 1, characterized in that: The calculation of the interpolation points, if the interpolation points are set according to the camera field of view angle and distance information, the camera field of view angle includes the horizontal field of view angle and the vertical field of view angle, the smaller field of view angle is used to calculate the number of interpolation points, and the shortest distance from the waypoint to the blade is d min , the field of view length is l, the field of view angle is β, the blade length is R, the number of interpolation points on the blade is n, n is an integer and satisfies the relevant calculation formula.

3. The wind turbine autonomous inspection strategy based on multi-directional viewpoint planning as claimed in claim 1, characterized in that: The focal length calculation is based on the principle of similar triangles. The average width of the blade is taken as X, 1 / 3 of the image width is taken as X, the distance from the waypoint to the interpolation point is taken as d, and the focal length of the camera is taken as f. The relevant calculation formula is satisfied to ensure that the focal length corresponding to each viewpoint makes the blade occupy a certain proportion in the image.

4. The wind turbine autonomous inspection strategy based on multi-directional viewpoint planning as claimed in claim 1, characterized in that: When calculating the waypoint coordinates when there is an upper blade tip and a lower blade tip, a specific set of equations must be satisfied. The relevant parameters are obtained by solving the set of equations and then the waypoint coordinates are calculated.

5. The wind turbine autonomous inspection strategy based on multi-directional viewpoint planning as claimed in claim 1, characterized in that: The three inspection waypoints and two transition waypoints, a total of five waypoints, are used to complete the wind turbine blade inspection, thereby minimizing the number of drone waypoints during the wind turbine inspection.

6. The wind turbine autonomous inspection strategy based on multi-directional viewpoint planning as claimed in claim 1, characterized in that: The process of the drone inspecting the wind turbine does not require human intervention, thus realizing autonomous inspection of the wind turbine.

7. The wind turbine autonomous inspection strategy based on multi-directional viewpoint planning as claimed in claim 1, characterized in that: The setting of the inspection waypoints, viewpoint planning, focal length calculation and setting of the transition waypoints are all based on full utilization of the UAV gimbal and camera focal length.

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