Tower imaging system for windmill

Abstract

To provide a tower imaging system that sets a suitable flight route for an imaging device mounted on a flight body in tower inspection corresponding to the type of a windmill, and images a tower according to the flight route.SOLUTION: There is provided a tower imaging system 100 for a windmill 70 that includes a flight body 10 having an imaging device 14, and a control device 30. The control device 30 creates a flight route consisting of a set of a plurality of flight target positions of the flight body 10 for imaging the tower 72 from all peripheral directions and transmits the flight route to the flight body 10 so as to image the tower 72 at a predetermined position of the tower such that blades 71 of the fixed windmill 70 do not overlap with the tower 72, and the flight body 10 makes an automatic flight along the flight route to image the tower 72 by the imaging device 14 at the flight target positions.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wind turbine tower imaging system. [Background technology]

[0002] In recent years, services that use drones equipped with cameras to inspect structures have been put into practical use, and the state of damage and deterioration of structures can be diagnosed based on images taken by the drone's camera. Using drones for inspection work at high altitudes, where it is difficult to secure scaffolding, has the advantage of making it easier to ensure the safety of workers and shortening the time required for inspection. Patent document 1 discloses a flight path generation device that can automatically fly an unmanned aerial vehicle equipped with a camera to generate a flight path for photographing structures (structures erected on the ground such as steel towers, power lines, and exhaust towers).

[0003] The flight path generation device of Patent Document 1 has an input device for inputting user instructions, a display, and a processing unit that performs processing for generating a flight path. First, a 3D image of the structure, a target area on the structure, and a shooting direction of the camera of the unmanned aerial vehicle heading toward the target area are displayed on the display. Next, the target area and the shooting direction are changed according to instructions input to the input device. When an instruction to determine the photographing target area and the photographing direction is input to the input device, the photographing position on the flight path of the unmanned aerial vehicle and the attitude of the camera that photographs the structure at that photographing position are calculated based on the determined photographing target area and photographing direction. The photographing position is calculated to be a predetermined distance from a virtual center line that passes through the structure in the vertical direction.

[0004] Furthermore, the structure inspection method of Patent Document 1 includes the following steps. In the first step (ST100), 3D shape data of the structure to be inspected is acquired. The 3D shape data is acquired by flying a UAV (Unmanned Aerial Vehicle) at a relatively distant location around the structure and taking multiple images of the structure as a whole, or by using a 3D measuring device such as a laser scanner. In the second step (ST105), a flight path for the UAV is created based on the 3D shape data acquired in the first step. In the third step (ST110), the UAV is automatically flown based on the flight path created in the second step to photograph the structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2020-149255 A Summary of the Invention [Problem to be solved by the invention]

[0006] In addition to the wind turbine blades, the towers that support the blades are also important areas to inspect. In light of the collapse of a wind turbine that occurred at the Rokkasho-mura Wind Power Plant in Aomori Prefecture on March 17, 2023, the Ministry of Economy, Trade and Industry requested an emergency inspection of the turbine installer of the same model as the collapsed turbine, in anticipation of the possibility of a similar accident occurring. According to an investigation by the turbine installer, the collapsed turbine had fractured at the welded part of the tower, and an inspection of the fractured surface revealed extensive fatigue cracks (presumed) penetrating the inside and outside surfaces, rust on the outside, and cracks in the paint on the inside. As these cracks, rust, and paint cracks can potentially be detected by visual inspections inside and outside the tower, it is expected that this information will be shared with installers of other types of wind turbines to prevent recurrence, and that urgent inspection requests will be made.

[0007] The emergency inspection items published on the website of the wind turbine installer are (Item 1) to (Item 3) below. (Item 1) Inspection of the outer welded seams of the tower. The outer surface of the tower will be inspected using a telephoto camera or similar device to confirm and record any rust on the circumferential welded seams. (Item 2) Inspection of the inner welded parts of the tower. Check and record whether there are any paint cracks or rust on the inner welded parts of the rusted welded parts confirmed in (Item 1). (Item 3) Detailed investigation. For any areas where cracks in the internal paint or rust have been found in (item 2), a non-destructive inspection is carried out as a detailed inspection to confirm the presence and extent of cracks. Examples of non-destructive inspections include UT (Ultrasonic Testing) and MT (Magnetic Particle Testing).

[0008] However, no structure inspection method suitable for photographing the tower to be inspected has been proposed. For example, in the method of Patent Document 1, the first step requires obtaining three-dimensional shape data of the structure, which takes time.

[0009] Therefore, the main objective of the present invention is to provide a tower imaging system that sets a suitable flight route for an imaging device mounted on an aircraft during tower inspection according to the type of wind turbine, and captures images of the tower according to that flight route. [Means for solving the problem]

[0010] In order to solve the above problems, the wind turbine tower imaging system of the present invention has the following features. The present invention provides a wind turbine tower imaging system including an aircraft having an imaging device and a control device, The control device, creating a flight route consisting of a collection of multiple flight destination positions of the aircraft for imaging the tower from all directions at a predetermined height position of the tower so that the blades of the fixed wind turbine are not overlapped with the tower, and transmitting the flight route to the aircraft; The flying object is characterized in that it flies automatically along the flight route and captures an image of the tower with the imaging device at the flight destination position. Other means will be described later. Effect of the Invention

[0011] According to the present invention, it is possible to provide a tower imaging system that sets a suitable flight route for an imaging device mounted on an aircraft during tower inspection according to the type of wind turbine, and images the tower according to that flight route. [Brief description of the drawings]

[0012] [Figure 1] 1 is an overall configuration diagram showing an outline of a tower imaging system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing the configuration of an aircraft according to the present embodiment. [Diagram 3] FIG. 4 is an explanatory diagram of an input information table according to the embodiment. [Figure 4] FIG. 4 is an explanatory diagram of a wind turbine-related table according to the embodiment. [Diagram 5] FIG. 2 is an explanatory diagram of a divided structure that constitutes the entire tower according to the present embodiment. [Figure 6] FIG. 2 is an explanatory diagram of the overall configuration of the tower according to the present embodiment. [Figure 7] FIG. 7 is an enlarged view of Sections 6 to 8 in FIG. 6 relating to this embodiment, and is an explanatory view relating to the positions of weld lines in the split structure. [Figure 8] FIG. 2 is an explanatory diagram relating to the concept of the central position of the wind turbine and the angle with the horizontal direction in this embodiment. [Figure 9] FIG. 11 is an explanatory diagram regarding an offset amount δ of the wind turbine according to the embodiment. [Figure 10] FIG. 4 is an explanatory diagram regarding a nacelle azimuth angle β according to the present embodiment. [Figure 11] 1 is an explanatory diagram of the separation distance L and the imaging range according to this embodiment. FIG. [Figure 12]FIG. 2 is an explanatory diagram of a circular orbit R according to the present embodiment. [Figure 13] 10 is a plan view showing an example of setting a flight target position in a first imaging mode according to the present embodiment. FIG. [Figure 14] 11 is a plan view showing an example of setting a flight target position in a second imaging mode according to this embodiment. FIG. [Figure 15] FIG. 2 is an explanatory diagram regarding the orientation of the flying object according to the present embodiment. [Figure 16] FIG. 11 is an explanatory diagram regarding rotation information θ of the flying object according to the embodiment. [Figure 17] FIG. 11 is a front view showing an example of the arrangement of blades fixed when imaging the tower according to this embodiment. [Figure 18] FIG. 2 is an explanatory diagram regarding the height position of the tower according to the present embodiment. [Figure 19] 10 is a plan view showing horizontal flight destination positions set in a first imaging mode according to this embodiment, and the imaging direction for each flight destination position. FIG. [Figure 20] 10 is a side view showing a vertical flight target position set in the first imaging mode according to this embodiment. FIG. [Figure 21] 13 is a plan view showing horizontal flight destination positions set in the second imaging mode according to this embodiment, and the imaging direction for each flight destination position. FIG. [Figure 22] 13 is a side view showing a vertical flight target position set in the second imaging mode according to this embodiment. FIG. [Figure 23] FIG. 4 is an explanatory diagram regarding a change in the nacelle azimuth angle according to the embodiment. [Figure 24] FIG. 11 is an explanatory diagram regarding points to note when performing regular observation according to the present embodiment. [Diagram 25] FIG. 2 is an explanatory diagram regarding flight route setting according to the present embodiment. [Figure 26] 10 is a flowchart showing the first half of the tower imaging process according to the present embodiment. [Figure 27] 13 is a flowchart showing the second half of the tower imaging process according to the embodiment. [Figure 28]FIG. 2 is an explanatory diagram of an image information database according to the embodiment. [Figure 29] FIG. 2 is a three-dimensional diagram of the wind turbine according to the embodiment when viewed from above. [Diagram 30] 1 is a three-dimensional view of a wind turbine according to an embodiment of the present invention, viewed from above in a plan view looking straight down. [Diagram 31] FIG. 2 is a three-dimensional view of the wind turbine according to the embodiment as viewed from the front. [Diagram 32] FIG. 2 is a three-dimensional view of the wind turbine according to the embodiment as viewed from the side. [Diagram 33] FIG. 2 is a hardware configuration diagram of each device of the tower imaging system according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0014] FIG. 1 is a diagram showing the overall configuration of a tower imaging system 100. As shown in FIG. Furthermore, blades 71a to 71c that rotate by wind force are attached to a tower 72 of a wind turbine 70 that is the subject of imaging by the tower imaging system 100. The tower 72 supports the blades 71a to 71c by a nacelle 73 and a hub 74 having a hub tip portion 74a (described later in FIG. 9).

[0015] The tower imaging system 100 includes an aircraft 10 and a control device 30. Various information is transmitted and received between the aircraft 10 and a controller (not shown), and various information is transmitted and received between the controller (not shown) and the control device 30. The control device 30 is a general computer system including an input / output unit 31, a processing unit 32, and a storage unit 33. The control device 30 creates a flight route for the flying object 10 to photograph the tower 72 while avoiding collision with the blades 71a to 71c in order to inspect the tower 72. The flight route is set with flight destination positions from the imaging start position to the imaging end position according to the imaging order.

[0016] Therefore, the control device 30 performs the following process. (Process 1) The type of wind turbine is identified based on the input information obtained from the input / output unit 31, and for each type of wind turbine, information for creating a flight destination position at the time of imaging according to the height of the wind turbine tower 72 is extracted from the wind turbine information database 33a. (Process 2) From the extracted information for creating the flight destination position at the time of imaging, a flight route consisting of a collection of multiple flight destination positions of the aircraft 10 for imaging the tower 72 from all directions is created. (Process 3) Transmit the flight route to the aircraft 10.

[0017] The flying object 10 automatically flies along the flight route and captures images of the tower 72 with the imaging device 14 at each flight destination position along the flight route. Various information can be transmitted and received between the aircraft 10 and a controller (not shown) operated by a pilot, and between the aircraft 10 and the control device 30. As a form of transmission and reception of this information, communication standards such as LTE (Long Term Evolution), 4G (fourth generation mobile communication system), and 5G (fifth generation mobile communication system) are appropriately used.

[0018] When inspecting the tower 72 of the wind turbine 70, the flying object 10 captures an image of the inspection target tower 72 with the imaging device 14 based on flight destination position information indicating the imaging order of the tower 72. Note that image information obtained by imaging is stored in a storage medium, either the storage unit 18 of the flying object 10 or the storage unit 33 of the control device 30. In cases where the image information resulting from the imaging cannot be transmitted directly from the aircraft 10 to the control device 30 due to restrictions under the Radio Law, the image information is stored in the memory unit 18 of the aircraft 10, and after inspection is completed, it is stored in a PC via an SD card or the like, and then transmitted from the PC via a network to the control device 30. In cases where there are no restrictions under the Radio Law, the image information is transmitted directly from the aircraft 10 to the control device 30 and stored in the memory unit 33 of the control device 30.

[0019] FIG. 2 is a perspective view showing the configuration of the aircraft 10. The aircraft 10 is an unmanned aerial vehicle that flies based on flight command information from a controller (not shown). For example, a drone is used as such an aircraft 10. The aircraft 10 includes a main body 11, arms 12a-12d, propellers 13a-13d (also called rotors or rotating wings), an imaging device 14, a camera arm M1, and skids K1 and K2. The main body 11 has a function of accommodating a control board (not shown) and various sensors (not shown) as well as holding the arms 12a to 12d and the camera arm M1. The arms 12a to 12d are rod-shaped members whose base ends are attached to the main body 11. In the example of FIG. 2, the arms 12a and 12b are attached to the front part of the side of the main body 11. In addition, other arms 12c and 12d are attached to the rear part of the side of the main body 11. These four arms 12a to 12d extend radially from the main body 11 in a plan view.

[0020] Propeller 13a is a rotor installed near the tip of arm 12a. Motor 15a (see FIG. 1) is provided with a central axis of rotation perpendicular to the direction in which arm 12a extends. Propeller 13a rotates in a predetermined manner as motor 15a (see FIG. 1) rotates. The same applies to propellers 13b to 13d installed in a one-to-one relationship on the remaining arms 12b to 12d.

[0021] Propellers adjacent in the circumferential direction (for example, propellers 13a, 13b) rotate in opposite directions. The propellers 13a to 13d rotate in conjunction with the driving of motors 15a to 15d (see FIG. 1), generating lift, and allowing the flying object 10 to fly. The rotation speeds of the motors 15a to 15d (see FIG. 1) are individually controlled, so that the flying object 10 can ascend and descend vertically and obliquely, as well as hover (stop in mid-air), move forward and backward, move left and right, and rotate left and right.

[0022] The imaging device 14 is a camera for capturing images of the blades 71a to 71c (see FIG. 1) of the wind turbine 70 (see FIG. 1). In the example of FIG. 2, the imaging device 14 is installed on the lower side of the main body 11 via a camera arm M1. Skids K1 and K2 are a pair of legs for grounding the aircraft 10 on the ground. Note that the configuration of the aircraft 10 is not limited to the example of FIG. 2.

[0023] Returning to FIG. 1, the configuration of the control system of the flying object 10 will be described. The aircraft 10 further includes a position and attitude sensor 16 , a communication unit 17 , a memory unit 18 , and a control unit 19 . The position / attitude sensor 16 is a sensor for acquiring information used to calculate the current position (flight position) and attitude (flight attitude) of the flying body 10. Although not shown, the position / attitude sensor 16 includes a receiver for receiving radio waves (navigation signals) transmitted from a predetermined navigation satellite, an acceleration sensor for measuring the acceleration of the flying body 10, an electronic compass for measuring the direction of the flying body 10, and a gyro sensor for measuring the angular velocity of the flying body 10. It is advisable to use the Global Navigation Satellite System (GNSS) for the radio waves (navigation signals) transmitted from a specific navigation satellite. This makes it possible to obtain highly accurate positioning information including the latitude and longitude of the aircraft 10 at every moment. As shown in FIG. 1, each measurement value of the position and attitude sensor 16 is output to the control unit 19.

[0024] The communication unit 17 is a communication module that communicates with a controller (not shown) or the control device 30. The communication unit 17 receives flight destination position information via the controller (not shown) or from the control device 30 and outputs it to the control unit 19.

[0025] Although not shown, the storage unit 18 includes non-volatile memory such as a ROM (Read Only Memory) and an HDD (Hard Disk Drive), and volatile memory such as a RAM (Random Access Memory) and a register. Various programs and data are stored in the storage unit 18. The various programs include a program for defining the flight route and flight attitude of the aircraft 10 when inspecting the tower 72. The various data includes position and attitude information and route information of the aircraft 10. Details of the position and attitude information and route information will be described later.

[0026] The control unit 19 is, for example, a CPU (Central Processing Unit), which reads out and develops various programs and various data stored in the storage unit 18, and executes predetermined processing. The control unit 19 includes, as functional components realized by the programs, a position and attitude calculation unit 19a, a flight control unit 19b, an imaging command unit 19c, and an image information output unit 19d.

[0027] The position / attitude calculation unit 19a calculates the current flight position and flight attitude of the aircraft 10 based on each measurement value of the position / attitude sensor 16. In this embodiment, in order to improve the detection accuracy of the current flight position of the aircraft 10, the aircraft 10 is configured to acquire high-precision positioning information based on RTK (Real Time Kinematic)-GNSS positioning. The source from which the high-precision positioning information is acquired may be, for example, a data distribution system (not shown) based on an electronic reference point (not shown), or an RTK base station (reference station: not shown).

[0028] In addition, the position / attitude calculation unit 19a calculates the latitude, longitude, and altitude of the flying object 10 based on the navigation signal input from the position / attitude sensor 16, and converts it into data of the flight position in the coordinate system of the flight space based on a predetermined conversion rule. In addition, the position / attitude calculation unit 19a calculates the orientation of the flying object 10 in the coordinate system of the flight space based on the measurement signal of an electronic compass (not shown) input from the position / attitude sensor 16. In addition, the position / attitude calculation unit 19a calculates the current flight attitude of the flying object 10 in the coordinate system of the flight space based on the measurement signal of an acceleration sensor (not shown) and a gyro sensor (not shown) input from the position / attitude sensor 16, as well as the orientation of the flying object 10. The position / attitude information calculated by the position / attitude calculation unit 19a is stored in the storage unit 18.

[0029] The flight control unit 19b controls the motors 15a-15d so that the moment-to-moment position and attitude information of the aircraft 10 conforms to the predetermined route information. The predetermined route information is information that specifies the flight route and flight attitude of the aircraft 10 during inspection of the tower 72, and is transmitted from the control device 30 via a controller (not shown) or from the control device 30 to the aircraft 10. The flight route of the flying object 10 is a continuous link of flight destination position information from the imaging start position to the imaging end position of the tower 72 to be inspected based on the imaging order. The flying object 10 moves at a predetermined moving speed between flight destination positions, and the moving speed of the flying object 10 is set to be approximately zero (hovering state) at the flight destination position. When the setting of the attitude, etc. of the flying object 10 at the predetermined flight destination position is completed, the flight control unit 19b outputs an imaging possible flag to the imaging command unit 19c.

[0030] When an imaging possible flag is input from the flight control unit 19b, the imaging command unit 19c outputs an imaging command signal to the imaging device 14. This causes the tower 72 to be inspected to be imaged. When imaging of the tower 72 is completed, the imaging command unit 19c outputs an imaging end flag to the flight control unit 19b. When an imaging end flag is input from the imaging command unit 19c, the flight control unit 19b moves the flying object 10 to the next flight destination position based on a predetermined flight route.

[0031] When image information that is the imaging result of the imaging device 14 is input, the image information output unit 19d outputs this image information to the storage unit 18 in association with "tower-related information" for identifying the tower 72 to be imaged and "imaging conditions" at the flight destination position. As a result, the image information that is the imaging result of the tower 72 to be inspected is stored in the storage unit 18. The stored image information is stored in the PC from the storage unit 18 via the storage medium, and is transmitted from the PC to the control device 30 via the network.

[0032] A controller (not shown) controls the flying object 10 in a predetermined manner based on route information transmitted from the control device 30 and measurement values ​​of each sensor of the flying object 10. Although the pilot can also operate the controller (not shown), in this embodiment, the operation performed by the pilot is merely to turn on the controller (not shown) and set it to a state in which data can be transmitted and received. Therefore, there is no particular need for the pilot to operate the position or attitude of the aircraft 10.

[0033] The control device 30 has a function of creating a flight route for the flying object 10 and managing the imaging results of the imaging device 14. Although not shown, a computer having a ROM, a RAM, a CPU, and various interfaces is used as the control device 30. As shown in FIG. 1, the control device 30 includes an input / output unit 31, a processing unit 32, and a storage unit 33.

[0034] The input / output unit 31 communicates with a controller (not shown) or the flying object 10, and also functions as a user interface. The input / output unit 31 acquires predetermined input information from the wind turbine information database 33a based on a user's operation. Here, the "input information" refers to information used to specify the tower 72 to be inspected, and further to specify the flight destination position of the flying object 10 when imaging the tower 72. In addition, the input / output unit 31 transmits the flying object control information and attitude control information set by the processing unit 32 to the flying object 10 via a controller (not shown). Here, the “aircraft control information” refers to the flight destination position of the aircraft 10 when imaging the tower 72. The "attitude control information" is information on the horizontal rotation angle of the flying object 10 that is set so that the imaging device 14 faces the center position of the tower at each flight destination position. The input / output unit 31 also has a function of receiving image information that is the imaging result of the tower 72 to be inspected.

[0035] The processing unit 32 creates a flight route for the aircraft 10 and manages image information of the tower 72. Details will be described later, but the processing unit 32 has at least the following functions (Function A) to (Function D). (Function A) The processing unit 32 acquires input information such as site information, unit information, imaging mode information, and nacelle azimuth angle information from the input / output unit 31, and extracts the height position and separation distance of the tower to be inspected from the wind turbine information database 33a based on the site information and unit information. (Function B) The processing unit 32 extracts all horizontal directions angles corresponding to the imaging mode from the wind turbine information database 33a based on the imaging mode.

[0036] (Function C) The processing unit 32 calculates the flight destination position (X (latitude), Y (longitude), Z (altitude)) based on the height position, separation distance, horizontal angle, and nacelle azimuth angle information extracted from the wind turbine information database 33a. (Function D) The processing unit 32 sets the flight destination position from the imaging start position to the imaging end position according to the imaging order, creates a flight route, and transmits it to the flying object 10.

[0037] The storage unit 33 stores a wind turbine information database 33a in advance, and also updates an image information database 33b as appropriate. The wind turbine information database 33a is a database for managing information used to capture images of the tower 72. The image information database 33b is a database for managing image information that is the result of capturing images of the tower 72. The wind turbine information database 33a is configured to include an input information table 41 (see FIG. 3) and a wind turbine-related table 42 (see FIG. 4).

[0038] FIG. 3 is an explanatory diagram of the input information table 41. As shown in FIG. The input information table 41 is a data table in which predetermined input information input via the input / output unit 31 (see FIG. 1) is stored. The site column 41a stores site identification information indicating the location of the wind turbine 70 (see FIG. 1). The location of the site is identified based on the site identification information. A predetermined number indicating individual identification information of the wind turbine 70 is stored in the wind turbine number column 41b.

[0039] The imaging mode column 41c stores imaging mode information for multiple horizontal angles of the imaging device 14 that is set in advance to capture images of the tower 72 from all directions and that is applied to all wind turbines. There are two types of imaging mode information: a first imaging mode indicating horizontal angles from "four directions" and a second imaging mode indicating horizontal angles from "five directions", and one of the imaging mode information is selected and stored.

[0040] The nacelle azimuth angle column 41d stores the nacelle azimuth angle, which is the direction indicated by the direction of the hub tip 74a attached to the front side of the nacelle 73, as the direction indicated by the entire nacelle. This nacelle azimuth angle is specified by angle information within the range of 0° to 359°. In the present invention, it is assumed that fixed, predetermined blades are arranged in the direction indicated by this nacelle azimuth angle. This blade arrangement will be described later.

[0041] FIG. 4 is an explanatory diagram of the wind turbine-related table 42. The wind turbine-related table 42 is a data table that stores information about the wind turbine 70 (see FIG. 1) and the tower 72 (see FIG. 1). The site column 42a stores identification information of the site indicating the location of the wind turbine 70. In the turbine number column 42b, a predetermined number indicating the turbine number information of the wind turbine 70 is stored. The wind turbine model column 42c stores information indicating the model of the wind turbine 70. The hub height column 42d stores information about the height from the ground surface GL (Ground Line) to the hub center of the wind turbine 70. The section number column 42e stores the total number of divided structures that indicate the shape of a truncated cone that constitutes the entire tower 72.

[0042] The wind turbine center position (latitude) column 42f and the wind turbine center position (longitude) column 42g store the latitude and longitude of the center position of the ground contact surface of the tower 72 of the wind turbine 70. The height position column 42h stores the height position (Z coordinate) from the origin point (Z=0) when the ground surface on which the tower 72 is grounded is set as the origin point of the height position. The separation distance column 42k stores a predetermined separation distance in the horizontal direction from the center position of the tower 72 on the horizontal plane of the tower 72 for each height position. The imaging mode column 42m stores imaging mode information associated with all horizontal angles for determining the horizontal position when imaging the tower 72 from the circumferential direction. The horizontal angle 1 column 42n to the horizontal angle 5 column 42s store horizontal angle information associated with the imaging mode.

[0043] In the wind turbine-related table 42, each piece of information in the site column 42a and the unit column 42b corresponds to each piece of information in the site column 41a and the unit column 42b of the input information table 41 (see FIG. 3). The control device 30 then determines the corresponding wind turbine type column 42c from the combination of “site column 42a, unit column 42b” in the wind turbine-related table 42 that matches the combination of “site column 41a, unit column 41b” in the input information table 41. In other words, the site and unit information is a key for linking the input information table 41 and the wind turbine-related table 42. Furthermore, the control device 30 extracts from the wind turbine-related table 42 the height position, separation distance, and horizontal angle (which are the same record in the table) that correspond to the determined wind turbine type column 42c. Although the method of managing the horizontal angle in the wind turbine-related table 42 of the wind turbine information database 33a has been described so far, it is also possible to use a method of minimizing the amount of information managed in the wind turbine-related table 42. In this case, the information managed in the wind turbine-related table 42 is limited to the central position (longitude) 42g of the wind turbine. Specifically, the reference angle of the nacelle azimuth angle, the horizontal angle of each of the two imaging modes ("4 directions" and "5 directions") at the reference angle, and the height position and separation distance corresponding to the type of wind turbine are determined in advance, and the processing unit 32 of the control device 30 extracts "height position, separation distance, central position (latitude, longitude) of the wind turbine, and reference angle of the nacelle azimuth angle" which are information required to calculate the flight destination position from the wind turbine information database 33a based on the input information "site, unit number, imaging mode, and nacelle azimuth angle (current angle)". Then, the processing unit 32 calculates the amount of change in the angle of the nacelle azimuth angle (amount of change from the reference angle to the current angle), corrects the horizontal angle by reflecting the amount of change in the angle, and calculates the rotation information and flight destination position (latitude, longitude) at the corrected horizontal angle. Furthermore, the processing unit 32 calculates the flight destination position (altitude) from the height position. Then, the processing unit 32 creates a flight route in which all the calculated flight destination positions (latitude, longitude, altitude) are arranged in order from the image capture start position to the image capture end position, and transmits the flight route and the rotation information and horizontal angle corresponding to each flight destination position from the temporary storage area provided in the storage unit 33 to the storage unit 18 of the flying object 10. According to this method, the number of calculation opportunities of the processing unit 32 of the control device 30 increases, but the information managed in the wind turbine information database 33a can be minimized. This method is effective when there are few types of wind turbines.

[0044] Next, the information in the wind turbine information database 33a in FIG. 1 (that is, the tables in FIG. 3 and FIG. 4) will be described in more detail. 5 is an explanatory diagram of the divided structures that make up the entire tower 72. The divided structures are shaped like truncated cones, and the tower 72 is made up of a plurality of divided structures stacked on top of each other. The dimensions of each divided structure in the height direction are unequal. The total number of divided structures that make up the tower 72 (the number of sections) is managed in the section number column 42e of the wind turbine-related table 42. In addition, each divided structure is assigned a section number (e.g., Section No. P) as an individual identification number, and the information to be managed for each divided structure includes the wall thickness t, the outer diameter of the upper base surface DPa, the outer diameter of the lower base surface DPb, the cone height HP, and the weld line position HP-Q, which is the height position from the lower base surface to the weld line where the entire circumference is welded.

[0045] Fig. 6 is an explanatory diagram of the overall configuration of the tower 72. The tower 72 is configured by stacking a plurality of divided structures from the bottom of the tower, and each divided structure is assigned a section number (section No. 1 to No. 14 in Fig. 6) that is an individual identification number in order from the top to the bottom of the tower. The tower 72 is also divided into three blocks [upper side (top), center (middle), and lower side (bottom)], and the boundary between each block has a flange portion (not shown) on the inner surface side of the tower that is fastened in the circumferential direction by a plurality of bolts.

[0046] FIG. 7 is an enlarged view of Sections No. 6 to No. 8 in FIG. 6, and is an explanatory diagram of the weld line positions of the divided structures. The weld line positions where the full circumference welding is applied are the boundary parts of each section and the predetermined positions of the divided structures with a large cone height. In the divided structures with a large cone height, multiple truncated cones of a predetermined cone height are stacked, so that the joints of the truncated cones are welded full circumference on the outer and inner sides. After the full circumference welding is applied, painting is applied for the purpose of rust and corrosion prevention. In the inspection of the outer surface weld line of the tower 72, which is one of the items to be inspected in the emergency inspection, the outer surface of the tower is inspected to confirm and record the rusted parts of the circumferential weld line, and the location is identified.

[0047] Fig. 8 is an explanatory diagram regarding the concept of the central position of the wind turbine and the horizontal angle. The central position of the wind turbine (the central position of the tower 72 in a plan view) is the central position of the tower ground surface at the location where the wind turbine is located, expressed as (latitude, longitude). For the horizontal angle, the concept of azimuth angle (angle rotated clockwise with true north as 0°) is used, with the east-west direction defined as the X-axis direction and the north-south direction defined as the Y-axis direction. In the example of Fig. 12, the central position of the wind turbine is expressed as the X-coordinate and Y-coordinate values ​​(X0, Y0).

[0048] 9 is an explanatory diagram regarding the wind turbine offset amount 6. The offset amount 6 is the horizontal distance from the center position of the wind turbine (the center position of the tower 72 in a plan view) to the central axes (rotation axes) of the blades 71a to 71c.

[0049] Fig. 10 is an explanatory diagram of the nacelle azimuth angle β. W in Fig. 10 shows a simplified diagram of the blades 71a, nacelle 73, and hub 74 in a plan view, and the direction indicated by the direction of the hub tip 74a (see Fig. 9) of the wind turbine is expressed as the direction of the entire nacelle as the nacelle azimuth angle β. In the example of Fig. 10, a reference angle β0 of the nacelle azimuth angle β is set to be used as a reference for setting the horizontal angle described below. In this example, an azimuth angle of 0° is set as the reference angle (β0 = 0°) of the nacelle azimuth angle β, but the reference angle is not limited to an azimuth angle of 0°.

[0050] FIG. 11 is an explanatory diagram relating to the separation distance L and the imaging range. The imaging device 14 includes a lens 14a and an image sensor 14b. The lens 14a is an optical element that refracts light and focuses it on the image sensor 14b. The image sensor 14b photoelectrically converts the light incident through the lens 14a to generate image information. The imaging range of the imaging device 14 is a range that can be imaged by the imaging device 14, which is configured by X and Y in Fig. 11 and is determined by the separation distance L. The separation distance L is set in advance within a range in which the imaging device 14 focuses on the tower 72 when imaging the tower 72, based on the performance of the imaging device 14 (lens 14a, image sensor 14b, focal length, angle of view, etc.). In this embodiment, in the wind turbine-related table 42 (see Fig. 4), a predetermined separation distance L (separation distance column 42k) is associated with each Z coordinate (height position column 42h) according to the type of wind turbine (wind turbine type column 42c).

[0051] The height of the tower 72 of the wind turbine 70 often reaches several tens of meters. Therefore, when the tower 72 is imaged by the imaging device 14, the tower 72 is divided into several parts from the bottom to the top and imaged. The tower 72 has a truncated cone shape, and the diameter becomes smaller toward the top of the tower. Therefore, the separation distance L is appropriately set within the range where the imaging device 14 can focus at a predetermined height position in the vertical direction according to the shape of the tower 72. The separation distance L at a predetermined height position in the vertical direction (Z coordinate) is stored in advance in the wind turbine-related table 42 (see FIG. 4).

[0052] FIG. 12 is an explanatory diagram of the circular orbit R. The circular orbit R shown in FIG. 12 is a set of points whose horizontal distance from the center position (X0, Y0) of the tower is a predetermined separation distance L. In other words, the circular orbit R is a virtual circle whose center is the center position (X0, Y0) of the tower and whose radius is the separation distance L. As described in FIG. 11, the separation distance L is set within a range in which the imaging device 14 (see FIG. 18) can be focused. The flight destination position (X coordinate, Y coordinate) when imaging the tower 72 is formed on the circular orbit R. The separation distance L differs depending on a predetermined height position (Z coordinate) in the vertical direction (see FIG. 4). Therefore, the radius of the circular orbit R (i.e., the separation distance L) also differs depending on the predetermined height position.

[0053] An example of setting a flight destination position on the circular orbit R in FIG. 12 will be described below. (First imaging mode) Example of setting flight destination positions at four points on a circular orbit R (Second imaging mode) Example of setting flight destination positions at five points on a circular orbit R

[0054] Fig. 13 is a plan view showing an example of setting a flight target position in the first imaging mode. Fig. 13 shows an example in which the X and Y coordinates of the intersections determined by horizontal angles α1 to α4 on a circular orbit R are set to the first point (X1, Y1) to the fourth point (X4, Y4), which are horizontal positions. The horizontal angle α is the angle formed in the horizontal plane of the tower 72 at a certain height (Z coordinate) between the center (X0, Y0) of the tower 72, the intersection with the reference line on the circular orbit R (reference angle β=0° of the nacelle azimuth angle β shown in FIG. 10), and the flight destination position (first point to fourth point). In other words, the reference line is a line extending from the center (X0, Y0) of the tower 72 in the direction of the reference angle β0=0° of the nacelle azimuth angle β onto the circular orbit R.

[0055] For example, the center of the tower 72 and a first point (X1, Y1) on the circular orbit R are connected by a first line segment. When this first point (X1, Y1) is set as the flight destination position, its horizontal angle = α1. Similarly, the horizontal angle = α2 of the second point (X2, Y2), the horizontal angle = α3 of the third point (X3, Y3), and the horizontal angle = α4 of the fourth point (X4, Y4) are defined.

[0056] Fig. 14 is a plan view showing an example of setting a flight destination position in the second imaging mode. Fig. 14 shows an example in which the X and Y coordinates of the intersections determined by horizontal angles α1 to α5 on the circular orbit R are set as the first point (X1, Y1) to the fifth point (X5, Y5), which are horizontal positions. Compared to Fig. 13, the horizontal angle = α5 of the fifth point (X5, Y5) has been added.

[0057] 13 and 14, it is assumed that the nacelle azimuth angle β is set to the reference angle β0. Furthermore, the control device 30 sets the horizontal angle α according to at least one of the policies listed below. -Enables imaging of the tower from all directions without the designated blade overlapping the tower. The imaging angle should be shifted a certain angle clockwise from the nacelle azimuth angle. Ensure that no images are missed around the circumference of the tower 72. The specified side lap ratio (degree of overlap with adjacent images in the circumferential direction) is made small.

[0058] 13 and 14, the nacelle azimuth angle β is set to a reference angle β0=0°. This horizontal angle α is set as a relative angle from the nacelle azimuth angle, since even if the current value of the nacelle azimuth angle β is changed from the reference angle β0, it is necessary to maintain the same horizontal angle for the changed nacelle azimuth angle. In FIGS. 13 and 14, the horizontal angle α is "α (absolute angle) = nacelle azimuth angle β + Δα (relative angle)", and is a function of the nacelle azimuth angle β. All horizontal angles are stored in advance in the wind turbine-related table 42 (see FIG. 4) in association with the imaging mode information.

[0059] Specifically, the control device 30 sets the flight destination position through the following (Step 1) to (Step 5). Note that (Step 5) may be omitted. (Step 1) In a horizontal plane at a height position (Z coordinate), a circular orbit R is formed with a radius equal to a predetermined horizontal distance from the center position (X0, Y0) of the tower 72. (Step 2) At the center position (X0, Y0), a line segment extending from the center position (X0, Y0) to the circular orbit is set as the reference line at a central angle position rotated clockwise by the nacelle azimuth angle β from true north. (Step 3) At the center position (X0, Y0), from the position of the central angle formed by rotating clockwise by each horizontal angle from the reference line, the intersection point between the straight line extending onto the circular orbit and the circular orbit is determined as the relative position of the center position (X0, Y0). (Step 4) Based on the latitude and longitude information of the central position (X0, Y0), the latitude and longitude information of the relative position is calculated, and the flight destination position is determined by the height position and the latitude and longitude information of the relative position. (Step 5) When the nacelle azimuth angle β is changed from the reference angle β0, the horizontal angles α1 to α4 are also changed accordingly in the example of FIG. 13. * From α4 * The first point (X1 * ,Y1 * ) to the fourth point (X4 * ,Y4 * ) is calculated.

[0060] The flying body 10 determines a predetermined horizontal angle for the towers 72 of all the wind turbines 70 and then captures images of the towers 72. For this reason, the control device 30 has two imaging mode information for capturing images of the towers 72: a "first imaging mode" indicating horizontal angles in "four directions" and a "second imaging mode" indicating horizontal angles in "five directions". The control device 30 sets the flying body 10 to one of the imaging modes. Then, the control device 30 extracts all horizontal angles corresponding to the imaging mode information from the wind turbine-related table 42, and sets the flight destination position (X (latitude), Y (longitude), Z (altitude)) at the current value of the nacelle azimuth angle as a flight route for the flying object 10.

[0061] Hereinafter, a process will be described in which the control device 30 performs attitude control (rotation control) on the flying object 10 that has arrived at the flight destination position so that the orientation of the imaging device 14 is aligned with the center of the tower. Fig. 15 is an explanatory diagram regarding the orientation of the flying object 10. Below, a case will be described in which the orientation B of the flying object 10 and the orientation A of the imaging device 14 are the same as shown in Fig. 15. On the other hand, a case in which the orientation of the flying object 10 and the orientation of the imaging device 14 are different is also assumed. In either case, rotation information can be obtained as described later in Fig. 16.

[0062] FIG. 16 is an explanatory diagram regarding rotation information θ of the flying object 10. The rotation information θ is information for controlling the attitude of the flying object 10 so that the imaging device 14 faces the center position of the tower after the flying object 10 moves to the flight destination position. The rotation information θ is information indicating the horizontal rotation angle of the flying object 10 based on a predetermined orientation. FIG. 16 shows an example of obtaining the rotation information θ1 at the first point (X1, Y1) using the horizontal angle α1. The rotation information θ is calculated as a function of the horizontal angle α, "rotation information θ (absolute angle) = horizontal angle α + predetermined angle", and based on this rotation information θ, the attitude of the flying object 10 is controlled so that the imaging range (FIG. 11) of the imaging device 14 faces the center of the tower 72. This attitude control may involve rotating the entire flying object 10 including the imaging device 14, or it may involve rotating only the imaging device 14 without rotating the flying object 10. As a result, after the flying object 10 has moved to the flight destination position, the attitude of the flying object 10 is controlled so that the imaging device 14 faces the central position.

[0063] Here, when the tower imaging system 100 is imaging, it is desirable that the three blades 71a to 71c are fixed in predetermined positions without rotating in consideration of a collision with the flying object 10. FIG. 17 is a front view showing an example of the arrangement of the blades 71a to 71c that are fixed when the tower 72 is imaged. In FIG. 17, three blades 71a to 71c are fixed in a Y-shape when viewed from the front direction opposite to the direction indicated by the nacelle azimuth angle β=0°. This "Y-shape" blade arrangement is defined as "arrangement information." Based on this arrangement information, the horizontal angle when imaging the tower is set and the flight destination position is calculated. This arrangement information is applied to all wind turbine towers.

[0064] That is, in the "Y-shaped" blade arrangement, blade 71a (predetermined blade) is fixed facing vertically downward (negative direction of the Z axis). The other blades 71b and 71c are fixed above the top of the tower in Fig. 6. Therefore, there is no need to consider collision of blades 71b and 71c with flying object 10 passing through a flight route below the top of the tower. The operation of the wind turbine 70 to achieve the "Y" blade arrangement is as follows. After power generation by the wind turbine is stopped, the nacelle azimuth angle is changed so that the front of the wind turbine faces the wind direction. The worker visually checks the rotation of the blades, which are freely rotating due to the force of the wind, and operates the brake switch to stop the specified blade when it is pointing vertically downward. A specific blade is fixed in place by inserting a mechanical lock pin or other method to prevent the blade from rotating. - If the nacelle azimuth angle is changed after the fixed arrangement, it is done while maintaining this blade arrangement.

[0065] Note that the "Y-shaped" blade arrangement shown in Figure 17 is merely one example for creating a flight route that allows the flying object 10 to photograph the tower 72 without colliding with the blades 71a to 71c and without the imaging device 14 overlapping (being blocked by) the blades 71a to 71c, and the blade arrangement may be fixed to another shape other than the "Y-shape."

[0066] FIG. 18 is an explanatory diagram regarding the height position of the tower 72. The height position of the flight destination position (photography position) is set as the height position from the starting point (Z=0) which is the ground surface GL (Ground Line) that is the ground surface of the tower. Note that unlike the section numbers, the height Zn increases as its value n increases, such as height ZP corresponding to section No. 1 in Figure 6, height Z9 corresponding to section No. 2, ..., height Z=0 corresponding to section No. 14. The wind turbine-related table 42 (see FIG. 4) prestores the hub heights (hub height column 42d) of the towers 72 determined corresponding to the wind turbine type column 42c. Furthermore, the wind turbine-related table 42 prestores height positions 42h (Z coordinates) for capturing images of a predetermined imaging range, determined from the hub height in consideration of the overlap rate (degree of overlap between adjacent images in the vertical direction) and the like.

[0067] An example of setting a flight destination position, including the height direction, will be described in detail below. (First imaging mode) Example of setting flight destination positions at four points on a circular orbit R (The horizontal flight destination positions have already been explained in Figure 13) (Second imaging mode) Example of setting flight destination positions at five points on a circular orbit R (The horizontal flight destination positions have already been explained in Figure 14)

[0068] FIG. 19 is a plan view showing flight destination positions in the horizontal direction set in the first imaging mode and the imaging direction for each flight destination position. As described in FIG. 13, the control device 30 sets flight destination positions (positions where photographs are taken in sequence from the first point to the fourth point) at four horizontal angles (α1 to α4) as a horizontal flight route. In addition, as described in FIG. 16, the control device 30 performs rotation control on the flying object 10 to bring the tower 72 into the imaging range at each flight destination position.

[0069] Here, the imaging range of the imaging device 14 needs to be set so that the blade 71a can be imaged without overlapping with the tower 72 (so that the blade 71a is not positioned in front of the tower 72 and obstructs the image capture). Therefore, the control device 30 sets at least one of the flight destination position and the rotation information θ so as to obtain such an imaging range of the imaging device 14. For example, in FIG. 19, the flight destination position and the rotation information θ are set so as to avoid the front side (between horizontal angles α4 and α1) where the blade 71a is in the foreground and the tower 72 is in the background.

[0070] FIG. 20 is a side view showing the flight target position in the vertical direction set in the first imaging mode. 20, for example, a flight route is set in which the (X, Y) position is fixed and the flight direction is changed from the bottom height Z1 of the shooting position to the top height ZP, and the flight direction is changed from the top height ZP of the shooting position to the bottom height Z1. The upper limit of the flight route (=top height ZP) is set to a position lower than the top of the hub height of the tower 72 by a predetermined amount (for example, 1 m). That is, the control device 30 transmits to the flying object 10 a flight route including flight destination positions arranged so as to move the flying object 10 in the height direction within a range lower than the top of the tower 72 while fixing the horizontal position. The flying object 10 then moves in the height direction so as to pass through each flight destination position in the order in which the flight destination positions are arranged on the flight route. As a result, the images taken successively become consecutive images (images with adjacent section numbers in FIG. 6) in the vertical direction of the tower 72. This makes it easier to smoothly combine the images at the seams between the photographs taken in the vertical direction of the tower 72, making it easier to find damage to the tower 72.

[0071] On the other hand, as a flight route different from that in Figure 20, it is also possible to photograph α1 → α2 → α3 → α4 at the lowest height Z1, then after a slight rise, photograph α4 → α3 → α2 → α1 at height Z2, and after a slight rise, photograph α1 → α2 → α3 → α4 at height Z3.

[0072] In the case of wind turbine 70, even if blades 71a-71c are stopped during inspection, depending on the stopping position of blades 71a-71c, there is a concern that the flight route may be blocked and a collision with aircraft 10 may occur. Therefore, by creating a flight route that satisfies the following (Condition 1) to (Condition 4), control device 30 can cause aircraft 10 to capture images of tower 72 without missing any images while avoiding collision with aircraft 10. (Condition 1) As described in FIG. 17, the three blades 71a to 71c are fixed in a "Y-shape" with one of them (blade 71a) facing vertically downward (approximately parallel to tower 72). (Condition 2) As explained in FIG. 19, the imaging range of the imaging device 14 is set to a flight destination position of the flight route such that the blade 71a can be imaged without overlapping with the tower 72. (Condition 3) As explained in Figure 20, the upper limit of the flight route height must be lower than the top of the hub height of the tower 72. (Condition 4) The flight destination must not be set within a range of height Xm from the ground surface. (*The value of height Xm is the height of the largest obstacle around the bottom of the tower at the location of the wind turbine.) When inspecting a wind turbine tower, it is essential to take into consideration obstacles near the ground (utility poles, power lines, trees, etc.). Since these obstacles are environmental differences specific to each individual tower, the flight destination position within the above range is set individually by the user, taking into account interference with obstacles, and is therefore not covered by the flight route of this invention.

[0073] On the other hand, as a comparative example, the method of Patent Document 1 shows that the "relay position" which is the passing position of the UAV added to form a flight path that bypasses the structure is located on the first cylinder C1 of the flight path. Therefore, if the blade stops in a way that blocks the flight path, it is not possible to prevent a collision between the flying object and the blade. In other words, in the method of Patent Document 1, if the stopping position of the blade interferes with the set flight path, the intermediate positions set for the purpose of bypassing the structure are meaningless, and it is not possible to prevent a collision between the aircraft and the blade.

[0074] In the first imaging mode described above, the control device 30 calculates each flight destination position on the flight route in the following procedure. (Step 1) Based on the center position (X0, Y0) of the tower, the separation distance L associated with a specific height position, and the horizontal angles α1 to α4 associated with the imaging mode information, a circular orbit is formed in the horizontal plane of the tower 72 at the height position, with the center position (X0, Y0) of the tower 72 as the center and the separation distance L as the radius. (Step 2) At the central position, a line segment extending from the central position to the circular orbit is set as a reference line at a central angle position rotated clockwise from true north by the amount of nacelle azimuth angle information. (Step 3) At the center position, the intersection of the straight line extending into the circular orbit and the circular orbit is calculated as the flight destination position (X (latitude), Y (longitude), Z (altitude)) from the position of the central angle formed by rotating clockwise from the reference line by each horizontal angle.

[0075] In other words, the control device 30 determines a plurality of flight destination positions that are the same predetermined height but have different horizontal positions. In this determination process, the control device 30 extracts the central position of the tower 72 to be imaged and the distance from that central position from the wind turbine information database 33a, and forms a circular orbit with a radius equal to the distance from the central position in a horizontal plane at a specified height. Then, the control device 30 extracts multiple horizontal angles formed by a reference line extending in a predetermined direction from the central position from the wind turbine information database 33a, and determines the intersection of the straight line extending from the central position in the direction of each horizontal angle and the circular orbit as each flight destination position. The control device 30 determines the direction from the central position, which is the center (X0, Y0) of the tower 72, toward the position of the hub tip 74a attached to the nacelle 73 that supports the wind turbine blades 71, as the predetermined direction for setting the reference line.

[0076] Then, the flying object 10, for which a flight route for the first imaging mode has been set, photographs the tower 72 along the flight route in the following procedure. (Step 1) Move from the takeoff and landing point near the tower to the bottom (X1, Y1, Z1) of horizontal angle α1, which is the imaging start position. (Step 2) While flying along a route from the bottom to the top on the outbound route, images of the tower 72 are taken at each flight destination position set from Z1 at the bottom to (X1, Y1, ZP) at the top. (Step 3) After imaging at horizontal angle α1 is completed, the camera moves to the next position (X2, Y2, ZP) at horizontal angle α2. (Step 4) While flying back along a route from the top to the bottom, images of the tower 72 are taken at each flight destination position set from the top (X2, Y2, ZP) to the bottom (X2, Y2, Z1). In this way, the aircraft 10 passes through all of the set flight destination positions from the imaging start position to the imaging end position by alternating between these angular movements and forward or return movements at each horizontal angle.

[0077] FIG. 21 is a plan view showing flight destination positions in the horizontal direction set in the second imaging mode and the imaging direction for each flight destination position. As described in FIG. 14, the control device 30 sets flight destination positions (positions where photographs are taken in sequence from the first point to the fifth point) at five horizontal angles (passing through α1 to α5 in sequence) as a horizontal flight route.

[0078] FIG. 22 is a side view showing the vertical flight target position set in the second imaging mode. In the second imaging mode of Figure 22, as in the first imaging mode of Figure 20, the control device 30 sets a flight route for the flying object 10 that passes through all flight destination positions set from the imaging start position to the imaging end position by alternating between angle movement and forward or return movement for each horizontal angle.

[0079] FIG. 23 is an explanatory diagram regarding the change in the nacelle azimuth angle. 23 shows an example in which the nacelle azimuth angle is changed from the reference angle β0 = 0° to β = 90°. As the nacelle azimuth angle is changed, the position of the fixed wind turbine blade arrangement is changed, and the horizontal angle α, which is set as a relative angle from the nacelle azimuth angle, and the rotation information θ, which is a function of the horizontal angle, are also changed.

[0080] FIG. 24 is an explanatory diagram regarding points to note when performing regular observation. In the example of Fig. 24, the nacelle azimuth angle β is set to 90° when the tower 72 is first imaged (first time). In order to perform regular observations, it is difficult to grasp changes over time unless the same location (same surface) is continuously imaged, so when imaging the same tower 72 for the second or subsequent times through regular observation, the nacelle azimuth angle β must be adjusted to the same angle as when it was first imaged. (In this example, the nacelle azimuth angle β when the first image was taken is 90°, so β ​​is set to 90° from the second time onwards.) Also, from the viewpoint of continuously imaging the same location (same surface), the imaging mode information must also be adjusted in the same way.

[0081] FIG. 25 is an explanatory diagram regarding flight route setting. The flight route is based on the current value of the nacelle azimuth angle β in the input information table 41, and according to a pre-stored predetermined rule, the imaging order is formed so that when the horizontal angle is changed (e.g., symbol C in FIG. 28), the order of flight destination positions Z (altitude) is reversed on the outbound and return journeys. This is because, in order to efficiently capture images of the tower, when the horizontal angle is changed, the aircraft moves by the shortest distance to the same height position of the next horizontal angle set. The control device 30 sets the flight destination position from the imaging start position to the imaging end position, and sets this as the "flight route" of the aircraft 10.

[0082] FIG. 26 is a flow chart showing the first half of the tower imaging process. In S300, the processing unit 32 of the control device 30 acquires input information from the input / output unit 31 (site, unit number, imaging mode, and current value of the nacelle azimuth angle). In other words, the processing unit 32 acquires from the input / output unit 31 site information 41a (see FIG. 3) indicating the location of the wind turbine 70, unit number information 41b indicating the individual identification information of the wind turbine 70, imaging mode information 41c for imaging the tower 72, and nacelle azimuth angle information 41d indicating the angle rotated clockwise from due north to the center line of the blades 71 of the wind turbine 70 facing vertically downward. Furthermore, the control device 30 sets a line segment extending from the center position of the tower 72 to a circular orbit at a central angle position rotated clockwise from true north by the amount of nacelle azimuth angle information as a reference line.

[0083] In S310, the processing unit 32 extracts the height position, separation distance, and horizontal angle from the wind turbine information database 33a based on the input information (site, unit number, imaging mode). To this end, the processing unit 32 first identifies the type of wind turbine from the wind turbine-related table 42 by specifying the site and unit number. The processing unit 32 then extracts the "wind turbine center position (latitude, longitude), height position, and separation distance" that are specified for each wind turbine type from the wind turbine-related table 42. The processing unit 32 also extracts all "horizontal angles" that correspond to the imaging mode from the wind turbine-related table 42 based on the "imaging mode" of the input information.

[0084] That is, the control device 30 extracts information for creating a flight destination position when capturing an image of the tower according to the tower height (height position 42h) determined by the type of wind turbine, from the wind turbine information database 33a, based on the input information (site information 41a, unit information 41b, and imaging mode information 41c in FIG. 3) acquired from the input / output unit 31. The information for creating the flight destination position is composed of, for example, center positions 42f, 42g of the tower 72, a predetermined horizontal distance 42k from the center position, and all horizontal angles 42n-42s corresponding to the imaging mode information 42m.

[0085] In S320, the processing unit 32 extracts a reference angle β0 of the nacelle azimuth angle that is set in advance (although this is not shown in the wind turbine-related table 42) and all horizontal angles α that correspond to the imaging modes from the wind turbine-related table 42. In S330, the processing unit 32 calculates the angle change amount (Δβ=β−β0) of the nacelle azimuth angle. In S340, the processing unit 32 calculates the horizontal angle α of the nacelle azimuth angle β (current value) based on the angle change amount Δβ. * , rotation information θ * The angle change amount Δβ is reflected in the horizontal angle α of the reference angle to calculate α * The horizontal angle α is calculated by the formula: rotation information θ = horizontal angle α + predetermined angle. * Rotation information θ * Here, the processing unit 32 forms a circular orbit on a horizontal plane at the height position, the circular orbit having a radius equal to the distance from the center position of the tower 72. Then, the process shifts from terminal A in FIG. 26 to terminal A in FIG.

[0086] FIG. 27 is a flowchart showing the latter half of the tower imaging process. In S350, the processing unit 32 calculates all flight destination positions at the current value of the nacelle azimuth angle β. To this end, the processing unit 32 obtains an intersection point between a straight line extending into a circular orbit and the circular orbit from the position of the central angle formed by rotating clockwise by each horizontal angle from the reference line at the center position of the tower 72 as a relative position of the center position of the tower 72, and calculates latitude information and longitude information of the relative position based on the latitude information and longitude information of the center position of the tower 72. Then, the processing unit 32 configures the flight destination position using the height position and the latitude information and longitude information of the relative position.

[0087] In S360, the processing unit 32 creates a flight route. That is, the processing unit 32 creates a flight route consisting of a collection of multiple flight destination positions of the flying object 10 for imaging the tower 72 from all directions at a predetermined height position of the tower 72 so that the blades 71 of the fixed wind turbine 70 are imaged without overlapping with the tower 72. In S370, the processing unit 32 transmits the created flight route to the aircraft 10. The transmitted flight route is stored in the memory unit 18 of the aircraft 10. In S380, the imaging device 14 of the flying object 10 automatically flies along the flight route and captures an image of the tower 72 by the imaging device 14 at the flight destination position. Here, the flying object 10 automatically flies so as to pass through all the flight destination positions in the order in which the flight destination positions are arranged. In addition, after moving to the flight destination position, the flying object 10 performs attitude control of the flying object 10 so that the imaging device 14 faces the center of the tower 72.

[0088] In S390, the processing unit 32 acquires image information from the aircraft 10. That is, the control unit 19 of the aircraft 10 transmits to the control device 30 information linking the image information of the captured tower 72 (shooting date and time 339 and image name 340 in FIG. 28 ), related information for identifying the captured tower 72 (site information 331 and aircraft number information 332), and imaging conditions including the imaging position and imaging direction for each image information (flight destination positions 336-338, imaging mode information 333, and nacelle azimuth angle information 334). In S400, the processing unit 32 stores in the image information database 33b the image information and the information linked to the image information received from the flying object 10. When the processing of S400 is performed from the imaging start position to the imaging end position, the processing ends.

[0089] 28 is an explanatory diagram of the image information database 33b. The image information acquired from the flying object 10 is stored in the image information database 33b of the storage unit 33 in association with the "tower-related information" and "imaging conditions" shown below. The tower-related information is information for identifying the tower 72 to be imaged, and has a site column 331 and a unit column 332 . The site column 331 is site information indicating the location of the wind turbine. The unit number column 332 is individual identification information of the wind turbine.

[0090] The imaging conditions are information for identifying the imaging conditions of each image information, and include an imaging mode column 333, a nacelle azimuth column 334, a horizontal angle column 335, and a flight destination position (X: latitude column 336, Y: longitude column 337, Z: altitude column 338). The imaging mode column 333 is information indicating the imaging mode used when imaging the tower. The nacelle azimuth angle column 334 is angle information of the nacelle azimuth angle β at the time the tower is imaged. The horizontal angle column 335 is information on the horizontal angle at the time the tower was imaged. Flight destination position X (latitude column 336), Y (longitude column 337), and Z (altitude column 338) are information on the flight destination position at the time of tower image capture.

[0091] The image capture date and time column 339 is time information added when the image capture device 14 captures an image of the tower 72 . The image name column 340 is information indicating an image name given to the image information when the tower 72 is imaged.

[0092] The flight route has been explained separately in the horizontal direction (X, Y) (Figs. 19 and 21) and in the vertical direction (Z) (Figs. 20 and 22). Here, to make the flight route easier to understand intuitively, a three-dimensional explanation (X, Y, Z) will be given with reference to Figs. 29 to 32. The three-dimensional diagrams in Figs. 29 to 32 are each an example of photographing the same tower 72 along the same flight route.

[0093] FIG. 29 is a three-dimensional view of the wind turbine 70 as seen from a bird's-eye view. In the wind turbine 70, blade 71a is fixed facing vertically downward, and three blades 71a to 71c form a Y shape, similar to Fig. 17. Each flight destination position around the tower 72 is indicated by a dot, and Fig. 29 also shows a flight route indicated by a broken line connecting the dots. As explained in Fig. 20, this flight route is set to move upward from the imaging start position 901, and then alternate between downward and upward movements, passing through the imaging end position 902 in order.

[0094] Figure 30 is a three-dimensional view of the wind turbine 70 as viewed from above looking straight down. As described in Figure 19, the flight route is set so as to avoid the front side where the hub tip portion 74a is located as much as possible. FIG. 31 is a three-dimensional view of the wind turbine 70 as seen from the front. FIG. 32 is a three-dimensional view of the wind turbine 70 as seen from the side.

[0095] FIG. 33 is a hardware configuration diagram of each device of the tower imaging system 100. Each device of the tower imaging system 100 (aircraft 10, controller (not shown), control device 30) is configured as a computer 900 having a CPU 901, RAM 902, ROM 903, HDD 904, communication I / F 905, input / output I / F 906, and media I / F 907. The communication I / F 905 is connected to an external communication device 915. The input / output I / F 906 is connected to an input / output device 916. The media I / F 907 reads and writes data from a recording medium 917. Furthermore, the CPU 901 executes a program (also called an application or its abbreviation, an app) loaded into the RAM 902, thereby improving and controlling each processing unit. This program can also be distributed via a communication line, or recorded on a recording medium 917 such as a CD-ROM and distributed.

[0096] According to the tower imaging system 100 described above, the process of acquiring 3D shape data of the tower 72 (structure) to be inspected can be replaced from a process of actually flying the aircraft 10 around the tower 72 to inspect it, to a process of reading data from the wind turbine information database 33a in which 3D shape data corresponding to the type of wind turbine 70 is registered in advance. Wind turbines of the same type are scattered throughout the country, and the dimensions and other information of each wind turbine are determined by the model of the wind turbine sold by the manufacturer. Therefore, if the information specified for each wind turbine model is registered in the wind turbine information database 33a, it will be possible to obtain the three-dimensional shape data of the tower 72 (structure) from the wind turbine information database 33a without having to inspect the actual wind turbine 70. Therefore, the control device 30 sets a suitable flight route for the imaging device mounted on the aircraft during tower inspection according to the type of wind turbine, and the aircraft 10 can capture images of the tower by following that flight route.

[0097] Furthermore, the present invention is not limited to the above-described embodiments, and various other applications and modifications are possible without departing from the gist of the present invention described in the claims. For example, the above-described embodiments are detailed and specific descriptions of the configuration of the tower imaging system 100 in order to easily explain the present invention, and are not necessarily limited to those including all of the components described. In addition, it is possible to replace a part of the configuration of one embodiment with a component of another embodiment. It is also possible to add a component of another embodiment to the configuration of one embodiment. It is also possible to add, replace, or delete other components to, a part of the configuration of each embodiment.

[0098] In addition, the above-mentioned configurations, functions, processing units, etc. may be realized in part or in whole by hardware, for example, by designing them as integrated circuits. As the hardware, a broad processor device such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) may be used. Furthermore, each component of the tower imaging system 100 according to the embodiment described above may be implemented in any hardware as long as each hardware can transmit and receive information to and from each other via a network. Furthermore, the processing executed by a certain processing unit may be realized by a single piece of hardware, or may be realized by distributed processing by multiple pieces of hardware. [Explanation of symbols]

[0099] 10 Flying Objects 11 Main unit 12 Arm 13 Propeller 14 Imaging device 14a Lens 14b Image sensor 15 Motor 16 Position and orientation sensor 17 Communications Department 18 Memory section 19 Control section 19a Position / attitude calculation section 19b Flight control unit 19c Imaging command section 19d Image information output section 30 Control device 31 Input / output section 32 Processing section 33 Storage section 33a Wind Turbine Information Database 41 Input Information Table 42 Windmill related table 33b Image information database 70 Windmill 71 Blade 72 Tower 73 Nacelle 74 Hub 74a Hub tip 100 Tower Imaging System

Claims

1. A wind turbine tower imaging system including an aircraft having an imaging device and a control device, The control device includes: creating a flight route consisting of a collection of multiple flight destination positions of the aircraft for imaging the tower from all directions at a predetermined height position of the tower so that the blades of the fixed wind turbine do not overlap with the tower, and transmitting the flight route to the aircraft; The flying object automatically flies along the flight route and captures an image of the tower with the imaging device at the flight destination position. Wind turbine tower imaging system.

2. The flying object is automatically flown so as to pass through all of the flight destination positions in the order in which the flight destination positions are arranged. The wind turbine tower imaging system according to claim 1.

3. The control device includes: obtains from an input / output unit site information indicating the location of the wind turbine, unit number information indicating the individual identification information of the wind turbine, imaging mode information for imaging the tower, and nacelle azimuth angle information indicating the angle rotated clockwise from true north to the center line of the blades facing vertically downward of the wind turbine blades, The image information of the tower is linked to tower-related information including the site information and the aircraft number information, and imaging conditions including the flight destination position, the imaging mode information, and the nacelle azimuth angle information, and the linked information is stored in a storage medium. The wind turbine tower imaging system according to claim 1 .

4. The control device includes: extracting, from a wind turbine information database, the height position, the center position of the tower, a predetermined horizontal distance from the center position, and all horizontal angles corresponding to the imaging mode information based on the site information, the unit information, and the imaging mode information; A circular orbit is formed on a horizontal plane at the height position, the circular orbit having a radius equal to the distance from the center position of the tower, At the center position of the tower, from the position of a central angle formed by rotating clockwise by each of the horizontal angles from a reference line, an intersection point between a straight line extending to the circular orbit and the circular orbit is obtained as a relative position of the center position of the tower, and latitude information and longitude information of the relative position are calculated based on the latitude information and longitude information of the center position of the tower, The flight destination position is determined based on the latitude and longitude information of the altitude position and the relative position. The wind turbine tower imaging system according to claim 3.

5. The control device includes: and at a central angle position rotated clockwise from the true north by the amount of the nacelle azimuth angle information at the central position of the tower, a line segment extending from the central position of the tower to the circular orbit is set as the reference line. The wind turbine tower imaging system according to claim 4.

6. After the flying object moves to the flight destination position, the flying object performs attitude control so that the imaging device faces the center position. The wind turbine tower imaging system according to claim 4.

Images