Wind power generation facility inspection method and unmanned aerial vehicle

Abstract

To provide an inspection method of a wind power generation system at a remote distance such as on the ocean by an unmanned aerial vehicle autonomically flying, and a configuration of the unmanned aerial vehicle used in this inspection method.SOLUTION: A controller provided on an unmanned aerial vehicle obtains a direction of a rotational axis of blades of a wind turbine at a first time point. The controller makes a camera mounted on the unmanned aerial vehicle shoot the blades of the wind mill while moving the unmanned aerial vehicle along a circumference of at least one front side circle which has a center axis in the same direction as the rotational axis of the blades of the wind mill at the first time point and on the same side as the blades with respect to a tower of the wind mill. The controller makes the camera mounted on the unmanned aerial vehicle shoot the blades of the wind mill along a circumference of at least one back side circle which has a center axis in the same direction as the rotational axis of the blades of the wind mill at the first time point and on the opposite side as the blades with respect to a tower of the wind mill.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present disclosure relates to a method for inspecting wind power generation facilities and an unmanned aerial vehicle. [Background technology]

[0002] The expansion of offshore wind power generation and its cost reduction are progressing rapidly worldwide. In particular, in Japan, where suitable locations for onshore wind power generation are limited, the expansion of offshore wind power generation is essential.

[0003] The proportion of post-construction operation and maintenance costs in the life cycle costs of offshore wind power generation facilities cannot be ignored. In recent years, as costs related to the construction of turbines and structures have decreased, the proportion of operation and maintenance costs is approaching the proportion of construction-related costs. Therefore, reducing the time and cost required for regular inspections and special inspections after emergency power generation shutdowns is extremely important for increasing the availability rate of wind power generation facilities and reducing power generation costs.

[0004] Conventionally, when inspecting the blades of wind turbines at wind power generation facilities, workers would use ropes hanging from the hub to move along the blades and visually check for damage, which made the inspection process very time-consuming.

[0005] Therefore, in order to reduce the burden on workers and cut inspection time and costs, various methods have been proposed for inspecting wind power generation equipment using unmanned aerial vehicles (UAVs) such as drones (see, for example, JP 2019-73999 A (Patent Document 1)). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-73999 Summary of the Invention [Problem to be solved by the invention]

[0007] When an offshore wind turbine at an offshore wind power generation facility is struck by lightning or other causes and the facility is forced to shut down, a temporary external inspection of the facility is required before operation can resume. Conventionally, the facility must be reached by ship for the external inspection, which takes time. Furthermore, depending on the strength of the waves, it may not be possible to approach the facility by ship.

[0008] In principle, it is possible to inspect wind turbines using UAVs by flying them back and forth between a base facility on land and an offshore wind power generation facility instead of using ships, but in practice, this poses many challenges. One challenge is that the specific procedures for inspecting wind power generation facilities using autonomous UAV flight are not clear. If an attempt is made to remotely control an offshore UAV in real time from a base facility on land, rather than using autonomous flight, a time lag occurs in control due to communication delays. As a result, if the situation around the UAV has changed by the time the control command reaches the UAV, the UAV cannot be remotely controlled as intended.

[0009] Similar issues can arise when inspecting wind power generation facilities located in remote areas on land, such as mountainous regions. Conventional technology assumes that UAVs are remotely controlled from a short distance where the wind turbines can be easily seen, and does not solve the above issues.

[0010] Therefore, one of the objects of the present disclosure is to provide a method for inspecting wind power generation facilities that are located far away, such as offshore, where they are difficult to see with the naked eye, using an autonomously flying unmanned aerial vehicle, and the configuration of the unmanned aerial vehicle used in this inspection method. [Means for solving the problem]

[0011] A method for inspecting wind power generation equipment in one aspect of the present disclosure includes the steps of: a controller provided on an unmanned aerial vehicle acquiring the direction of the rotational axis of the wind turbine blades at a first time point; a controller causing a camera mounted on the unmanned aerial vehicle to photograph the wind turbine blades while moving the unmanned aerial vehicle along the circumference of at least one front circle having a central axis in the same direction as the rotational axis of the wind turbine blades at the first time point and on the same side of the wind turbine tower as the blades; and a controller causing the camera mounted on the unmanned aerial vehicle to photograph the wind turbine blades while moving the unmanned aerial vehicle along the circumference of at least one back circle having a central axis in the same direction as the rotational axis of the wind turbine blades at the first time point and on the opposite side of the wind turbine tower from the blades.

[0012] A method for inspecting wind power generation facilities in one aspect of the present disclosure includes the steps of: a controller provided in an unmanned aerial vehicle acquiring the direction of the rotational axis of the wind turbine blades at a first time point; the controller moving the unmanned aerial vehicle along the periphery of a first circle, the first circle having a central axis in the same direction as the rotational axis at the first time point and on the same side of the wind turbine tower as the blades, and causing a camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades while the unmanned aerial vehicle is moving; a controller provided in the unmanned aerial vehicle acquiring the direction of the rotational axis of the wind turbine blades at a second time point; the controller moving the unmanned aerial vehicle along the periphery of a second circle having a central axis in the same direction as the rotational axis at the second time point and on the same side of the wind turbine tower as the blades, and causing the camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades while the unmanned aerial vehicle is moving. the controller acquiring the direction of the rotation axis of the wind turbine blades at a third time point; the controller moving the unmanned aerial vehicle along the periphery of a third circle having a central axis in the same direction as the rotation axis at the third time point and on the opposite side of the blades relative to the wind turbine tower, and causing the camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades while the unmanned aerial vehicle is moving; the controller acquiring the direction of the rotation axis of the wind turbine blades at a fourth time point; the controller moving the unmanned aerial vehicle along the periphery of a fourth circle having a central axis in the same direction as the rotation axis at the fourth time point and on the opposite side of the blades relative to the wind turbine tower, and causing the camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades while the unmanned aerial vehicle is moving.

[0013] An unmanned aerial vehicle in another aspect of the present disclosure includes a propulsion mechanism for propelling and hovering the unmanned aerial vehicle, a camera, and a controller for controlling the propulsion mechanism and the camera. The controller acquires the direction of the rotational axes of the wind turbine blades, moves the unmanned aerial vehicle along the periphery of at least one front-side circle having a central axis in the same direction as the rotational axes of the wind turbine blades and on the same side of the wind turbine tower as the blades, moves the unmanned aerial vehicle along the periphery of at least one rear-side circle having a central axis in the same direction as the rotational axes of the wind turbine blades and on the opposite side of the wind turbine tower as the blades, and causes the camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades while the unmanned aerial vehicle is moving. [Effects of the Invention]

[0014] According to the above one and other aspects, wind power generation facilities that are located at a distance that is difficult to see, such as offshore, can be inspected by an autonomously flying unmanned aerial vehicle. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is an external view conceptually illustrating an example configuration of a drone. [Figure 2] FIG. 2 is a functional block diagram showing the configuration of the drone in FIG. 1. [Figure 3] FIG. 1 is a diagram conceptually illustrating an example of the configuration of a wind turbine in an offshore wind power generation facility. [Figure 4] FIG. 2 is a functional block diagram showing an example of the configuration of a terminal device installed in a base facility. [Figure 5] 1 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed obliquely relative to the wind turbine 40. FIG. [Figure 6] FIG. 2 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from the front of the wind turbine 40. [Figure 7] FIG. 2 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from the rear side of the wind turbine 40. [Figure 8] FIG. 2 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from the side of the wind turbine 40. [Figure 9] 1 is a diagram showing the flight path of a drone 10 in the first embodiment as viewed from above a wind turbine 40. FIG. [Figure 10] 4 is a flowchart showing an inspection procedure for the wind turbine 40 in the first embodiment. [Figure 11] 10 is a diagram showing the flight path of a drone 10 in a second embodiment as viewed obliquely relative to a wind turbine 40. FIG. [Figure 12] 10 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from the front of the wind turbine 40. FIG. [Figure 13] 10 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from the rear side of the wind turbine 40. FIG. [Figure 14] FIG. 10 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from the side of the wind turbine 40. [Figure 15] FIG. 10 is a diagram showing the flight path of a drone 10 in the second embodiment as viewed from above a wind turbine 40. [Figure 16] 10 is a flowchart showing an inspection procedure for the wind turbine 40 in the second embodiment. [Figure 17] FIG. 11 is a diagram showing the flight path of a drone 10 in the third embodiment as viewed obliquely relative to a wind turbine 40. [Figure 18] FIG. 11 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from the front of the wind turbine 40. [Figure 19] FIG. 11 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from the rear side of the wind turbine 40. [Figure 20] FIG. 11 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from the side of the wind turbine 40. [Figure 21] FIG. 11 is a diagram showing the flight path of a drone 10 in the third embodiment as viewed from above a wind turbine 40. [Figure 22] 10 is a flowchart showing an inspection procedure for the wind turbine 40 in the fourth embodiment. [Figure 23] 10 is a flowchart showing an inspection procedure for the wind turbine 40 in the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, the embodiments will be described in detail with reference to the drawings. Hereinafter, the case of inspecting an offshore wind turbine using a UAV will be described as an example, but the same applies to inspecting a wind turbine installed in a remote area on land, such as a mountainous region. Furthermore, the UAV will be described as a drone as an example. Note that the same or corresponding parts will be given the same reference numerals, and their description may not be repeated.

[0017] [First embodiment] (Drone configuration example) Figure 1 is an external view conceptually illustrating an example of the configuration of a drone. Figure 1(A) shows an external view of the drone 10 as seen from the front, and Figure 1(B) shows an external view of the drone 10 as seen from the right side.

[0018] Fig. 2 is a functional block diagram showing the configuration of the drone of Fig. 1. Fig. 2 shows an example of the internal configuration of the main body 11 of Fig. 1 in more detail.

[0019] 1 and 2, drone 10 includes a propeller motor 13 and a propeller 14 connected to the upper part of main body 11 via arms 12, and legs 22 attached to the lower part of main body 11. A motor drive circuit 15 for driving propeller motor 13 is provided inside arms 12. Drone 10 also includes an engine 16 and a generator 17 attached to the lower part of main body 11, cameras 18 and 20 mounted on the lower part of main body 11 via gimbals 19 and 21, respectively, and a LiDAR (Laser Imaging Detection and Ranging) sensor 24 attached to the upper part of main body 11.

[0020] 1, four sets of propeller motors 13 and propellers 14 are provided, but this is not limited to this. By controlling the rotational speed of each propeller motor 13, it is possible for the drone 10 to ascend and descend vertically, ascend and descend in any diagonal direction, hover in mid-air, move forward, backward, move right, move left, rotate right, rotate left, etc. In other words, the propeller motors 13 and propellers 14 constitute a propulsion mechanism 23 that propels the drone 10 forward and stops it in mid-air.

[0021] The generator 17 is driven by the engine 16 to generate the power necessary for the operation of the drone 10. This enables the drone 10 to fly for long periods of time and in low temperatures.

[0022] Camera 18 is a forward camera 18 for capturing images in front of drone 10, and camera 20 is a nadir camera 20 for capturing images directly below drone 10. Forward camera 18 includes a high-resolution camera 18A for capturing inspection images and a low-resolution camera 18B for capturing video images for FPV (First Person View). Similarly, nadir camera 20 includes a high-resolution camera 20A for capturing inspection images and a low-resolution camera 20B for capturing FPV images. Video images captured by low-resolution cameras 18B and 20B are transmitted to a terminal device 70 at the base facility. This allows inspectors at the base facility to view the images captured by cameras 18B and 20B in real time. The shooting directions of cameras 18 and 20 can be adjusted by actuators constituting gimbals 19 and 21, respectively. The actuators constituting gimbals 19 and 21 can also be adjusted by signals from terminal device 70 at the base facility.

[0023] The gimbals 19 and 21 are electric actuators that can three-dimensionally adjust the orientation of the cameras 18 and 20. Based on the detection values ​​of the acceleration sensor and angular velocity sensor, the gimbals 19 and 21 can keep the imaging directions of the cameras 18 and 20 constant even if the attitude of the drone 10 changes.

[0024] The LiDAR sensor 24 detects the distance and angle to an object based on the light reflected from the object by scanning with a pulsed laser light. The LiDAR sensor 24 may be replaced with another distance sensor.

[0025] As shown in FIG. 2, the main body 11 incorporates a controller 30, a storage device 31, an inertial measurement unit 32, a transceiver 33, a GPS (Global Positioning System) receiver , a power supply circuit 35, a storage battery , and the like.

[0026] The controller 30 controls the operations of the motor drive circuit 15, the camera 18, the LiDAR sensor 24, etc. The controller 30 may be configured by a microcomputer including a CPU (Central Processing Unit), RAM (Random Access Memory), and non-volatile memory, or may be configured by an FPGA (Field Programmable Gate Array), or may be configured by a dedicated circuit such as an ASIC (Application Specific Integrated Circuit). The controller 30 may also be configured by a combination of at least two of these.

[0027] The storage device 31 includes, for example, a removable nonvolatile recording medium 38 such as an SD memory card, and a reader / writer 37 for writing data to the recording medium 38 and reading data from the recording medium 38. In accordance with commands from the controller 30, the reader / writer 37 stores, in the recording medium 38, still images for inspection taken by the camera 18, the control details of the controller 30, flight information, and the like.

[0028] The inertial measurement unit 32 is a sensor unit that integrates an acceleration sensor, an angular velocity sensor (gyro sensor), a geomagnetic sensor, an air pressure sensor, a temperature sensor, etc. into a single package. The controller 30 controls the autonomous flight and attitude of the drone 10 based on the detection values ​​of the various sensors in the inertial measurement unit 32.

[0029] The transceiver 33 transmits and receives information such as signals and data to and from the transceiver installed in the wind turbine to be inspected and the transceiver of the terminal device at the onshore base facility. For example, the transceiver 33 receives information on the operating status of the wind turbine and commands from the terminal device at the base facility. In addition, the transceiver 33 transmits monitoring video images taken by the low-resolution cameras 18B and 20B to the base facility in accordance with commands from the controller 30.

[0030] The GPS receiver 34 receives signals from GPS satellites. The controller 30 detects the current position of the drone 10 based on the signals received by the GPS receiver 34.

[0031] The power supply circuit 35 generates a power supply voltage for driving each part of the drone 10 based on the power generated by the generator 17.

[0032] The storage battery 36 is used as an auxiliary power source for the drone 10. For example, the storage battery 36 supplies power to drive the controller 30, the storage device 31, the transceiver 33, etc. while the engine 16 and the generator 17 are stopped.

[0033] (Example of wind turbine configuration) Fig. 3 is a conceptual diagram showing an example of the configuration of a wind turbine in an offshore wind power generation facility. Referring to Fig. 3, wind turbine 40 includes a nacelle 43 mounted on the top of tower 44, a hub 42, and three blades 41A, 41B, and 41C attached to hub 42. The bottom of tower 44 is connected to floating body 46 via base 45. This allows tower 44 to float above sea level 49.

[0034] The blades 41A, 41B, and 41C rotate about the axial direction of the rotor shaft 50 by rotation of the rotor shaft 50 connected to the hub 42. In addition, the angle (pitch angle 63) of the blades 41 about the longitudinal axis and the angle (yaw angle) of the nacelle 43, which can rotate about the longitudinal axis of the tower 44, can be adjusted. The rotor shaft 50 is the rotation axis KD of the blades 41A, 41B, and 41C. The rotation axis KD of the blades 41A, 41B, and 41C is perpendicular to the rotation plane of the blades 41A, 41B, and 41C.

[0035] The nacelle 43 houses a gearbox 52, a brake device 53, a generator 54, a controller 60, and a transceiver 61.

[0036] The speed increaser 52 is provided between the rotor shaft 50 and the power transmission shaft 51 and increases the rotational speed of the rotor shaft 50, causing the power transmission shaft 51 to rotate at the increased rotational speed. The brake device 53 stops the rotation of the power transmission shaft 51 in accordance with a command from the controller 60. The generator 54 generates AC power by the rotation of the power transmission shaft 51. The AC power generated by the generator 54 is transmitted to the transformer 56 via a power cable 55 and is boosted by the transformer 56. The AC power boosted by the transformer 56 is then transmitted to an onshore power facility via a power cable 57.

[0037] The controller 60 controls the overall operation of the wind turbine 40. For example, the controller 60 adjusts the pitch angle of the blades 41 and the yaw angle of the nacelle 43 based on the measurement results of wind direction and speed meters (not shown) installed on top of the nacelle 43. The hardware configuration of the controller 60 can be various, similar to the case of the controller 30 of the drone 10 shown in FIG. 2.

[0038] The controller 60 further exchanges information with the drone 10 and a base facility on land via a transceiver 61 and an antenna 62. The transceiver 61 may be configured to relay communication between the drone 10 and the base facility. Wired communication such as optical fiber communication may be used for communication between the wind turbine 40 and the base facility on land.

[0039] (Example of terminal device configuration at base facility) 4 is a functional block diagram showing an example of the configuration of a terminal device installed in a base facility. The terminal device 70 is used for monitoring the movement of the drone 10 and the inspection of the wind turbine 40, and for analyzing inspection images.

[0040] 4, the terminal device 70 is configured based on a computer including a CPU 71, a RAM 72, and a non-volatile memory 73. The terminal device 70 further includes a display device 74, an input device 75, a storage device 76, and a transceiver 78. These components are connected to each other via a bus 79.

[0041] A liquid crystal display, an organic EL (Electroluminescence) display, or the like can be used as display device 74. For example, display device 74 displays moving images captured by cameras 18B, 20B during inspection of wind turbine 40 and during movement between the onshore base facility and offshore wind turbine 40.

[0042] The input device 75 includes a keyboard, a mouse, and the like for receiving input to the terminal device 70 by the inspector.

[0043] The storage device 76 is configured to include a reader / writer for reading data from a removable recording medium. For example, the reader / writer of the storage device 76 can be equipped with a recording medium 38 that stores inspection images captured by the camera 18 of the drone 10.

[0044] The transceiver 78 communicates with the transceiver 33 of the drone 10 and the transceiver 61 of the wind turbine 40 via the antenna 77.

[0045] (Drone flight path) Fig. 5 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from an oblique direction relative to the wind turbine 40. Fig. 6 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from the front of the wind turbine 40. Fig. 7 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from the back of the wind turbine 40. Fig. 8 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from the side of the wind turbine 40. Fig. 9 is a diagram showing the flight path of the drone 10 in the first embodiment as viewed from above the wind turbine 40.

[0046] 5 to 9, circles CA and CB are shown as the flight path of the drone 10.

[0047] Circle CA has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a front circle on the same side of tower 44 of wind turbine 40 as the blades. The radius of circle CA is ra. The distance between the plane of circle CA and the plane of rotation of blades 41A, 41B, 41C is d1.

[0048] Circle CB has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a back circle on the opposite side of the blades with respect to tower 44 of wind turbine 40. The radius of circle CB is rb. The distance between the plane of circle CB and the plane of rotation of blades 41A, 41B, 41C is d2.

[0049] Here, ra=rb and d1=d2 may be set.

[0050] The vertical positions of the central axis SA of the circle CA and the central axis SB of the circle CB may be the same as or different from the vertical position of the rotation axis KD.

[0051] The flight path of this embodiment is more desirable when the direction of rotation axis KD of blades 41A, 41B, and 41C does not change over time, or if it does change over time, the amount of change is small. In this case, drone 10 flies circles CA and CB after first time point t1, but the relative positional relationships of circles CA and CB with respect to wind turbine 40 remain the same as at the first time point or do not change significantly.

[0052] (Inspection procedures for offshore wind turbines) Below, based on the configuration of the drone 10, wind turbine 40, and terminal device 70 described above, the inspection procedure for the wind turbine 40 of the offshore wind power generation facility will be described.

[0053] FIG. 10 is a flowchart showing the inspection procedure for the wind turbine 40 in the first embodiment.

[0054] In step S101, the terminal device 70 installed in the onshore base facility receives a notification from the offshore wind turbine 40 via the transceiver 78 that the generator 54 has been stopped in an emergency.

[0055] In step S102, the inspector starts the engine 16 and generator 17 of the drone 10, and further, for example, by executing a program, causes the controller 30 of the drone 10 to start an emergency inspection of the wind turbine 40. As a result, the drone 10 begins flying toward the wind turbine 40 to be inspected.

[0056] More specifically, the controller 30 of the drone 10 determines the flight direction of the drone based on its own position information based on the GPS signal received by the GPS receiver 34 and on the position information of the wind turbine 40 to be inspected received from the terminal device 70. The controller 30 controls the motor drive circuit 15 to cause the drone to take off to a sufficient height and then move the drone in the determined flight direction. The controller 30 continues to move the drone based on the position information from the GPS signal until it reaches the wind turbine 40 to be inspected.

[0057] In step S103, the controller 30 of the drone 10 determines the current time as a first time point t1 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the first time point t1. Specifically, the controller 60 of the wind turbine 40 adjusts the yaw angle of the nacelle 43 so that the rotation planes of the blades 41A, 41B, and 41C receive the wind head-on.

[0058] The controller 60 of the wind turbine 40 may transmit the direction of the rotation axis KD to the controller 30 of the drone 10.

[0059] Alternatively, the controller 30 of the drone 10 may determine the direction of the rotation axis KD of the blades 41A, 41B, and 41C. More specifically, the controller 30 uses the nadir camera 20 to capture an image of the nacelle 43 from a position above the wind turbine 40. Based on the captured image of the nacelle 43, the controller 30 detects the angle of deviation between the direction of the stopped nacelle 43 and the stopping direction of the drone (for example, the forward direction). The controller 30 detects the direction of the geomagnetic field using the geomagnetic sensor in the inertial measurement unit 32. Based on the detection result of the geomagnetic field, the controller 30 determines the current direction of the drone, and further determines the current direction of the nacelle 43, i.e., the direction of the rotation axis KD of the blades 41A, 41B, and 41C, from this determination result.

[0060] In step S104, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CA as shown in Figures 5, 6, 8, and 9.

[0061] In step S105, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CB as shown in Figures 5, 7, 8, and 9.

[0062] In step S106, the controller 30 of the drone 10 determines the damaged locations of the blades 41A, 41B, and 41C based on the captured images obtained in steps S104 and S105.

[0063] (effect) For example, one possible method is to have a drone fly automatically in a horizontal circle around the wind turbine to photograph the blades (horizontal flight). With this method, it is easy to set a flight route. However, with this method, in order to set a flight route so that the drone does not collide with the wind turbine and photographs all parts of the blades, the distance between the blades and the camera becomes large, which results in low quality images and a long inspection time.

[0064] According to the flight method of this embodiment, the distance between the blade and the camera can be reduced to less than half compared to the horizontal flight method, thereby improving the quality of the captured images and shortening the inspection time.

[0065] [Second embodiment] (Drone flight path) Fig. 11 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from an oblique direction relative to the wind turbine 40. Fig. 12 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from the front of the wind turbine 40. Fig. 13 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from the back of the wind turbine 40. Fig. 14 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from the side of the wind turbine 40. Fig. 15 is a diagram showing the flight path of the drone 10 in the second embodiment as viewed from above the wind turbine 40.

[0066] 11 to 15, circles CC, CD, CE, and CF are shown as the flight path of the drone 10.

[0067] Circle CC has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a front circle on the same side of tower 44 of wind turbine 40 as the blades. The radius of circle CC is rc. The distance between the plane of circle CC and the planes of rotation of blades 41A, 41B, 41C is d3.

[0068] Circle CD has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a front circle on the same side of tower 44 of wind turbine 40 as the blades. The radius of circle CD is rd. The distance between the plane of circle CD and the planes of rotation of blades 41A, 41B, 41C is d3.

[0069] The shortest distance between the circumference of circle CC and the circumference of circle CD is d5. The distance between the center of circle CC and the center of circle CD is d7.

[0070] Here, rc=rd may be set. The rotation axis KD may pass through the midpoint of the line segment connecting the center of circle CC and the center of circle CD.

[0071] Circle CE has a central axis in the same direction as rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a back circle on the opposite side of the blades with respect to tower 44 of wind turbine 40. The radius of circle CE is re. The distance between the plane of circle CE and the plane of rotation of blades 41A, 41B, 41C is d4.

[0072] Circle CF has a central axis in the same direction as rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a back circle on the opposite side of the blades with respect to tower 44 of wind turbine 40. Circle CF has a radius rf. The distance between the plane of circle CF and the plane of rotation of blades 41A, 41B, 41C is d4.

[0073] The shortest distance between the circumference of circle CE and the circumference of circle CF is d6. The distance between the center of circle CE and the center of circle CF is d8.

[0074] Here, re=rf may be set. The rotation axis KD may pass through the midpoint of the line segment connecting the center of the circle CE and the center of the circle CF.

[0075] Here, rc=rd=re=rf may be set, d3=d4 may be set, d5=d6 may be set, and d7=d8 may be set.

[0076] The vertical positions of the central axis SC of the circle CC, the central axis SD of the circle CD, the central axis SE of the circle CE, and the central axis SF of the circle CF may be the same as or different from the vertical position of the rotation axis KD.

[0077] The angle between the rotation axis KD and the line segment connecting the center of circle CC and point O where the rotation plane of blades 41A, 41B, and 41C intersects with the rotation axis KD is, for example, 45°, but may be any angle. The angle between the rotation axis KD and the line segment connecting the center of circle CD and point O where the rotation plane of blades 41A, 41B, and 41C intersects with the rotation axis KD is, for example, 45°, but may be any angle. The angle between the rotation axis KD and the line segment connecting the center of circle CE and point O where the rotation plane of blades 41A, 41B, and 41C intersects with the rotation axis KD is, for example, 45°, but may be any angle. The angle between the rotation axis KD and the line segment connecting the center of circle CF and point O where the rotation plane of blades 41A, 41B, and 41C intersects with the rotation axis KD is, for example, 45°, but may be any angle.

[0078] In this embodiment, as in the first embodiment, the flight path of this embodiment is more desirable when the direction of rotation axis KD of blades 41A, 41B, and 41C does not change over time, or if it does change over time, the amount of change is small. In this case, drone 10 flies along circles CC, CD, CE, and CF at times after first time point t1, but the relative positional relationships of circles CC, CD, CE, and CF with respect to wind turbine 40 remain the same as at the first time point or do not change significantly.

[0079] (Inspection procedures for offshore wind turbines) Below, based on the configuration of the drone 10, wind turbine 40, and terminal device 70 described above, the inspection procedure for the wind turbine 40 of the offshore wind power generation facility will be described.

[0080] FIG. 16 is a flowchart showing the inspection procedure for the wind turbine 40 in the second embodiment.

[0081] In step S201, the terminal device 70 installed in the onshore base facility receives a notification from the offshore wind turbine 40 via the transceiver 78 that the generator 54 has been stopped in an emergency.

[0082] In step S202, the inspector starts the engine 16 and generator 17 of the drone 10, and further, for example, by executing a program, causes the controller 30 of the drone 10 to start an emergency inspection of the wind turbine 40. As a result, the drone 10 begins flying toward the wind turbine 40 to be inspected.

[0083] In step S203, the controller 30 of the drone 10 determines the current time as a first time point t1 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the first time point t1.

[0084] In step S204, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CC as shown in Figures 11, 12, 14, and 15.

[0085] In step S205, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CD as shown in Figures 11, 12, 14, and 15.

[0086] In step S206, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CE as shown in Figures 11, 13, 14, and 15.

[0087] In step S207, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CF as shown in Figures 11, 13, 14, and 15.

[0088] In step S208, the controller 30 of the drone 10 determines the damaged locations of the blades 41A, 41B, and 41C based on the captured images obtained in steps S204 to S207.

[0089] [Third embodiment] (Drone flight path) Fig. 17 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from an oblique direction relative to the wind turbine 40. Fig. 18 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from the front of the wind turbine 40. Fig. 19 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from the back of the wind turbine 40. Fig. 20 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from the side of the wind turbine 40. Fig. 21 is a diagram showing the flight path of the drone 10 in the third embodiment as viewed from above the wind turbine 40.

[0090] 17 to 21, circles CG, CH, CI, CJ, CK, and CL are shown as the flight path of the drone 10.

[0091] Circle CG has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a front circle on the same side of tower 44 of wind turbine 40 as the blades. The radius of circle CG is rg. The distance between the plane of circle CG and the planes of rotation of blades 41A, 41B, 41C is d9.

[0092] Circle CH has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a front circle on the same side of tower 44 of wind turbine 40 as the blades. The radius of circle CH is rh. The distance between the plane of circle CH and the plane of rotation of blades 41A, 41B, 41C is d9.

[0093] Circle CI has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a front circle on the same side of tower 44 of wind turbine 40 as the blades. The radius of circle CI is ri. The distance between the surface of circle CI and the planes of rotation of blades 41A, 41B, 41C is d9.

[0094] The rotation axis KD may or may not pass through the center of the circle CH. The distance between the center of the circle CG and the center of the circle CH is d11. The distance between the center of the circle CI and the center of the circle CH is d12. Here, rg = rh = ri may be satisfied, or d11 = d12 may be satisfied.

[0095] Circle CJ has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a back circle on the opposite side of the blades with respect to tower 44 of wind turbine 40. The radius of circle CJ is rj. The distance between the plane of circle CJ and the plane of rotation of blades 41A, 41B, 41C is d10.

[0096] Circle CK has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a back circle on the opposite side of the blades with respect to tower 44 of wind turbine 40. The radius of circle CK is rk. The distance between the plane of circle CK and the plane of rotation of blades 41A, 41B, 41C is d10.

[0097] Circle CL has a central axis in the same direction as the rotation axis KD of blades 41A, 41B, 41C of wind turbine 40 at first time point t1, and is a back circle on the opposite side of the blades with respect to tower 44 of wind turbine 40. The radius of circle CL is rl. The distance between the plane of circle CL and the plane of rotation of blades 41A, 41B, 41C is d10.

[0098] The rotation axis KD may or may not pass through the center of the circle CK. The distance between the center of the circle CJ and the center of the circle CK is d13. The distance between the center of the circle CL and the center of the circle CK is d14. Here, rj = rk = rl may be satisfied, or d13 = d14 may be satisfied.

[0099] Here, rg=rh=ri=rj=rk=rl may be set, and d9=d10 may be set. Also, d11=d12=d13=d14 may be set.

[0100] The vertical positions of the central axis SG of the circle CG, the central axis SH of the circle CH, the central axis SI of the circle CI, the central axis SJ of the circle CJ, the central axis SK of the circle CK, and the central axis SL of the circle CL may be the same as or different from the vertical position of the rotation axis KD.

[0101] In this embodiment, as in the first and second embodiments, the flight path of this embodiment is more desirable when the direction of the rotation axis KD of blades 41A, 41B, and 41C does not change over time, or if it does change over time, the amount of change is small. In this case, the drone 10 flies along the circles CG, CH, CI, CJ, CK, and CL at times after the first time point t1, but the relative positional relationships of the circles CG, CH, CI, CJ, CK, and CL with respect to the wind turbine 40 remain the same as at the first time point or do not change significantly.

[0102] (Inspection procedures for offshore wind turbines) The inspection procedure for the wind turbine 40 in the third embodiment is similar to the inspection procedure for the wind turbine 40 in the first and second embodiments, and therefore the description will not be repeated.

[0103] In the first embodiment, the drone 10 is flown along the circumference of the circle CA and the circumference of the circle CB. In the second embodiment, the drone 10 is flown along the circumference of the circle CC, the circumference of the circle CD, the circumference of the circle CE, and the circumference of the circle CF. In the third embodiment, the drone 10 is flown along the circumference of the circle CG, the circumference of the circle CH, the circumference of the circle CI, the circle CJ, the circumference of the circle CK, and the circumference of the circle CL.

[0104] The inspection procedure for the wind turbine 40 in the third embodiment is substantially the same as the inspection procedure for the wind turbine 40 in the first and second embodiments, except for the number and number of flying circumferences. Therefore, a description of the inspection procedure for the wind turbine 40 in the third embodiment will not be repeated.

[0105] [Fourth embodiment] In the first to third embodiments, it is assumed that the direction of the rotation axes KD of the blades 41A, 41B, and 41C does not change over time, or if it does change over time, the amount of change is small. In this embodiment, before the drone 10 flies each circumference, it acquires the direction of the rotation axes KD of the blades 41A, 41B, and 41C, and flies a circumference determined based on the acquired direction. This allows the drone 10 to fly a desired flight path even if the direction of the rotation axes KD of the blades 41A, 41B, and 41C changes over time.

[0106] Below, we will explain an example in which the flight path in the second embodiment is modified so that the drone 10 flies a circle determined based on the direction of the rotation axis KD of the blades 41A, 41B, and 41C, which is acquired before the drone 10 flies each circle. Similar modifications can also be made to the first and third embodiments.

[0107] FIG. 22 is a flowchart showing the inspection procedure for the wind turbine 40 in the fourth embodiment.

[0108] In step S301, the terminal device 70 installed in the onshore base facility receives a notification from the offshore wind turbine 40 via the transceiver 78 that the generator 54 has been stopped in an emergency.

[0109] In step S302, the inspector starts the engine 16 and generator 17 of the drone 10, and further, for example, by executing a program, causes the controller 30 of the drone 10 to start an emergency inspection of the wind turbine 40. As a result, the drone 10 begins flying toward the wind turbine 40 to be inspected.

[0110] In step S303, the controller 30 of the drone 10 determines the current time as the first time point t1 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the first time point t1.

[0111] In step S304, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of a circle CC. The circle CC has a central axis in the same direction as the rotation axis KD of the blades 41A, 41B, and 41C of the wind turbine 40 at the first time point t1, and is a front-side circle on the same side of the tower 44 of the wind turbine 40 as the blades.

[0112] In step S305, the controller 30 of the drone 10 determines the current time as the second time point t2 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the second time point t2.

[0113] In step S306, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CD2. The circle CD2 has a central axis in the same direction as the rotation axis KD of the blades 41A, 41B, and 41C of the wind turbine 40 at the second time point t2, and is a front-side circle on the same side of the tower 44 of the wind turbine 40 as the blades.

[0114] In step S307, the controller 30 of the drone 10 determines the current time as the third time point t3 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the third time point t3.

[0115] In step S308, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CE2. The circle CE2 has a central axis in the same direction as the rotation axis KD of the blades 41A, 41B, and 41C of the wind turbine 40 at the third time point t3, and is a back circle on the opposite side of the blades with respect to the tower 44 of the wind turbine 40.

[0116] In step S309, the controller 30 of the drone 10 determines the current time as the fourth time point t4 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the fourth time point t4.

[0117] In step S310, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CF2. The circle CF2 has a central axis in the same direction as the rotation axis KD of the blades 41A, 41B, and 41C of the wind turbine 40 at the fourth time point t4, and is a back circle on the opposite side of the tower 44 of the wind turbine 40 from the blades.

[0118] In step S311, the controller 30 of the drone 10 determines the damaged locations of the blades 41A, 41B, and 41C based on the captured images obtained in steps S304, S306, S308, and S310.

[0119] [Fifth embodiment] In this embodiment, at the time of an emergency stop, the controller 60 of the wind turbine 40 adjusts the pitch angle 63 of the blades 41 so that the wind direction is parallel to the wind-receiving surfaces of the blades 41. This prevents the blades 41 from receiving lift from the wind, thereby preventing damage to the wind turbine 40.

[0120] An example in which the above-described control is added to the inspection procedure for the wind turbine 40 of the first embodiment will be described below.

[0121] FIG. 23 is a flowchart showing the inspection procedure for the wind turbine 40 in the fifth embodiment.

[0122] In step S101, the terminal device 70 installed in the onshore base facility receives a notification from the offshore wind turbine 40 via the transceiver 78 that the generator 54 has been stopped in an emergency.

[0123] In step S401, the controller 60 of the wind turbine 40 adjusts the pitch angle 63 of the blades 41 so that the wind direction and the wind-receiving surface of the blades 41 are parallel to each other.

[0124] In step S102, the inspector starts the engine 16 and generator 17 of the drone 10, and further, for example, by executing a program, causes the controller 30 of the drone 10 to start an emergency inspection of the wind turbine 40. As a result, the drone 10 begins flying toward the wind turbine 40 to be inspected.

[0125] In step S103, the controller 30 of the drone 10 determines the current time as a first time point t1 and acquires the directions of the rotation axes KD of the blades 41A, 41B, and 41C at the first time point t1.

[0126] In step S104, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CA.

[0127] In step S105, the controller 30 of the drone 10 causes the forward camera 18 to photograph the blades 41A, 41B, and 41C while flying the drone 10 along the circumference of the circle CB.

[0128] In step S106, the controller 30 of the drone 10 determines the damaged locations of the blades 41A, 41B, and 41C based on the captured images obtained in steps S104 and S105.

[0129] The wind turbine inspection method described in the above embodiment is intended for emergency inspection, but can also be applied to regular inspection.

[0130] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of this application is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0131] 10 drone, 11 main body, 12 arm, 13 propeller motor, 14 propeller, 15 motor drive circuit, 16 engine, 17, 54 generator, 18, 18A, 18B, 20, 20A, 20B camera, 19, 21 gimbal, 22 legs, 23 propulsion mechanism, 24 sensor, 30, 60 controller, 31, 76 storage device, 32 inertial measurement unit, 33, 61, 78 transmitter / receiver, 34 receiver, 35 power circuit, 36 storage battery, 37 reader / writer, 38 recording medium, 40 wind turbine, 41A, 41B, 41C blade, 42 hub, 43 nacelle, 44 tower, 45 base, 46 floating body, 49 sea surface, 50 rotor shaft, 51 power transmission shaft, 52 gearbox, 53 Braking device, 55 power cable, 56 transformer, 57 power cable, 62, 77 antenna, 70 terminal device, 72 RAM, 73 non-volatile memory, 74 display device, 75 input device, 79 bus.

Claims

1. A method for inspecting wind power generation equipment, comprising: A controller provided in the unmanned aerial vehicle acquires a direction of a rotation axis of a blade of the wind turbine at a first time point; the controller causes a camera mounted on the unmanned aerial vehicle to photograph the wind turbine blades while moving the unmanned aerial vehicle along the circumference of at least one front circle that has a central axis in the same direction as the rotation axis of the wind turbine blades at the first time point and is on the same side as the blades with respect to the tower of the wind turbine; A method for inspecting wind power generation equipment, comprising the steps of: the controller moving the unmanned aerial vehicle along the circumference of at least one back circle that has a central axis in the same direction as the rotation axis of the wind turbine blades at the first time point and is on the opposite side of the blades relative to the wind turbine tower, while causing a camera mounted on the unmanned aerial vehicle to photograph the wind turbine blades.

2. The method for inspecting a wind power generation facility according to claim 1 , wherein the vertical position of the central axis is the same as the vertical position of the rotation axis.

3. The method for inspecting a wind power generation facility according to claim 1 , wherein the at least one front-side circle includes two circles, and the at least one back-side circle includes two circles.

4. the at least one obverse circle is a first circle and a second circle; the rotation axis passes through the midpoint of a line segment connecting the center of the first circle and the center of the second circle, the at least one back circle is a third circle and a fourth circle; The method for inspecting a wind power generation facility according to claim 3 , wherein the rotation axis passes through a midpoint of a line segment connecting the center of the third circle and the center of the fourth circle.

5. A method for inspecting wind power generation equipment, comprising: A controller provided in the unmanned aerial vehicle acquires a direction of a rotation axis of a blade of the wind turbine at a first time point; the controller moving the unmanned aerial vehicle along a periphery of a first circle having a central axis in the same direction as the rotation axis at the first time point and on the same side of the wind turbine tower as the blades, and causing a camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades during the movement of the unmanned aerial vehicle; a controller provided on the unmanned aerial vehicle acquiring a direction of a rotation axis of a blade of the wind turbine at a second time point; the controller moving the unmanned aerial vehicle along a periphery of a second circle having a central axis in the same direction as the rotation axis at the second time point and on the same side of the wind turbine tower as the blades, and causing a camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades during the movement of the unmanned aerial vehicle; a controller provided in the unmanned aerial vehicle acquiring a direction of a rotation axis of the blade of the wind turbine at a third time point; the controller moving the unmanned aerial vehicle along a periphery of a third circle having a central axis in the same direction as the rotation axis at the third time point and on an opposite side of the blades with respect to the tower of the wind turbine, and causing a camera mounted on the unmanned aerial vehicle to take inspection images of the blades of the wind turbine during the movement of the unmanned aerial vehicle; a controller provided in the unmanned aerial vehicle acquiring a direction of a rotation axis of the blade of the wind turbine at a fourth time point; A method for inspecting wind power generation equipment, comprising the steps of: the controller moving the unmanned aerial vehicle along the periphery of a fourth circle having a central axis in the same direction as the rotation axis at the fourth time point and on the opposite side of the blades from the wind turbine tower; and causing a camera mounted on the unmanned aerial vehicle to take inspection images of the wind turbine blades while the unmanned aerial vehicle is moving.

6. the blades of the wind turbine are rotatable; The method for inspecting wind power generation equipment according to any one of claims 1 to 5, further comprising a step in which, at the time of an emergency stop of the wind turbine, a controller of the wind turbine adjusts the pitch angle of the blades so that the direction of the wind and the wind-receiving surfaces of the blades are parallel.

7. The method for inspecting wind power generation equipment according to any one of claims 1 to 5, wherein the wind turbine is installed offshore.

8. An unmanned aerial vehicle, a propulsion mechanism for propelling and hovering the unmanned aerial vehicle; A camera and a controller for controlling the propulsion mechanism and the camera; The controller Obtain the direction of the rotation axis of the wind turbine blades, moving the unmanned aerial vehicle around at least one near-side circle having a central axis in the same direction as the axis of rotation of the wind turbine blades and on the same side of the wind turbine tower as the blades; and moving the unmanned aerial vehicle around at least one far-side circle having a central axis in the same direction as the axis of rotation of the wind turbine blades and on an opposite side of the wind turbine tower as the blades; An unmanned aerial vehicle that causes a camera mounted on the unmanned aerial vehicle to take inspection images of the blades of the wind turbine while the unmanned aerial vehicle is moving.

Images