Inspection method for steelmaking heating furnaces

Abstract

To highly accurately perform imaging processing on a root side around a narrow place of a structure.SOLUTION: An inspection method of a heating furnace for iron manufacture according to the present disclosure comprises the steps of: making an unmanned flying object fly between a first structure 100A and a second structure 100B among a plurality of structures 100; adjusting the reference direction of an imaging direction of an imaging device 5 as a direction along an extension direction of the structure on the other side of the structures 100 in a state of being located on the one side of the structures 100; rotating the flying object 1 around a yaw axis with the extension direction of the structures 100 in the horizontal direction as the reference in a state of being maintained at the position on the one side; and generating a photographed image by the imaging device 5 in at least any of a state where the imaging direction of the imaging device 5 of the unmanned flying object 1 faces the first structure 100A side with respect to the reference direction and a state where the imaging direction faces the second structure 100B side with respect to the reference direction.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a method for inspecting a heating furnace for steel making. [Background technology]

[0002] There is a demand for labor-saving and time-saving inspections of steelmaking heating furnaces such as continuous annealing furnaces and batch annealing furnaces. Because heating furnaces are hot immediately after operation is stopped, if personnel are to work in the furnace, they must wait until the temperature drops to a level where they can be worked on. For this reason, it is being considered to use drones, for example, to start inspections earlier than if personnel were to work in the furnace.

[0003] For example, Patent Document 1 discloses a technology for inspecting furnace walls in a boiler using a drone. For example, in an inspection using a drone, an image of the inside of the furnace is captured using an imaging device such as a camera, and the captured image can be used to confirm the condition inside the furnace or to model the structure inside the furnace. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-127049 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the internal space of a steelmaking heating furnace, when the temperature is high, the influence of the air current inside is large. In particular, around narrow spaces of structures such as piping, the structure itself is also affected by the heat, and it is easy to be influenced by the air current, making it difficult to maintain a stable posture when taking images using a drone. In such structures, the resolution of the captured image on the base side of the structure is likely to vary, making it difficult to obtain highly accurate captured images.

[0006] Therefore, the present disclosure has been made in consideration of the above-mentioned problems, and its purpose is to provide an inspection method for a steel-making heating furnace that is capable of performing image processing around narrow spaces in a structure with high accuracy. [Means for solving the problem]

[0007] According to the present disclosure, there is provided a method for inspecting an iron-making heating furnace, in which an internal space of an iron-making heating furnace in which a plurality of structures are arranged substantially parallel along a horizontal direction, is imaged using an unmanned aerial vehicle, the method including: flying the unmanned aerial vehicle between a first structure and a second structure of the plurality of structures; positioning the unmanned aerial vehicle on one side in the horizontal extension direction of the structures, adjusting the reference direction of the imaging direction of the imaging device to be a direction on the other side of the structures and along the extension direction of the structures; rotating the unmanned aerial vehicle around a yaw axis while maintaining the unmanned aerial vehicle in the position on the one side; and generating an image by the imaging device of the unmanned aerial vehicle in at least one of a state in which the imaging direction of the imaging device of the unmanned aerial vehicle is facing toward the first structure relative to the reference direction and a state in which the imaging direction is facing toward the second structure relative to the reference direction. Effect of the Invention

[0008] According to the present disclosure, imaging processing of the base side around narrow spaces in a structure can be performed with high accuracy. [Brief description of the drawings]

[0009] [Figure 1] An oblique view showing an example configuration of an unmanned aerial vehicle 1 used in an inspection method according to one embodiment of the present disclosure. [Diagram 2] A diagram showing an example of the hardware configuration of the unmanned aerial vehicle 1 according to the embodiment. [Diagram 3] 4 is a flowchart showing an example of a flow of an inspection method for an iron-making heating furnace according to the embodiment. [Figure 4]A figure showing a first example of an imaging position and imaging direction of the unmanned aerial vehicle 1 according to the embodiment. [Diagram 5] A figure showing a second example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the same embodiment. [Figure 6] A figure showing a third example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the same embodiment. [Figure 7] A figure showing an example of an imaging position and imaging direction of an unmanned aerial vehicle 1 according to a first modified example of the same embodiment. [Figure 8] A figure showing an example of an imaging position and imaging direction of an unmanned aerial vehicle 1 according to a second modified example of the same embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In this specification and the drawings, components having substantially the same functional configurations are denoted by the same reference numerals, and redundant description will be omitted.

[0011] <Example of unmanned aerial vehicle configuration> Fig. 1 is a perspective view showing a configuration example of an unmanned aerial vehicle 1 used in an inspection method according to an embodiment of the present disclosure. In this specification, the X direction, Y direction, and Z direction shown in Fig. 1 respectively refer to the front-rear direction, width direction, and height direction of the unmanned aerial vehicle 1. The unmanned aerial vehicle 1 according to this embodiment is a rotorcraft that obtains lift and thrust by a plurality of rotors 3.

[0012] As shown in Fig. 1, the unmanned aerial vehicle 1 according to this embodiment includes a main body 2 and rotors 3. Note that the configuration of the unmanned aerial vehicle 1 shown in Fig. 1 is one example, and even if a rotorcraft has a structure, shape, and size different from the main body 2 and rotors 3 shown in Fig. 1, it may be included in the scope of the present invention as long as it has a configuration corresponding to the main body 2 and rotors 3 described below.

[0013] More specifically, the main body 2 is made up of a support frame 21 and an auxiliary frame 22. The auxiliary frame 22 is connected to the support frame 21. Specifically, the auxiliary frame 22 is connected to the support frame 21 so as to extend from both the front and rear directions. The auxiliary frame 22 includes an arm 23. As shown in FIG. 1, the rotor 3 is supported by the arm 23. Note that the arm 23 according to this embodiment is also connected to the support frame 21. The material constituting the main body 2 is not particularly limited, and may be, for example, carbon fiber resin, glass fiber resin, magnesium, magnesium alloy, aluminum, aluminum alloy, steel, titanium, or other materials.

[0014] The support frame 21 supports components related to the control and power of the flight of the unmanned aerial vehicle 1, such as a circuit board, a flight controller, or a battery (not shown). For example, a control circuit including a flight controller may be mounted on the support frame 21. Power is supplied from the battery to the motor 20 and a sensor (described later), and the rotation speed of the motor 24 is controlled by the flight controller.

[0015] The auxiliary frame 22 constitutes the body of the unmanned aerial vehicle 1, is connected to the support frame 21, and supports the rotor 3. In the example shown in Fig. 1, the auxiliary frame 22 extends in the front-rear direction from the front-rear end of the support frame 21, and extends to the left and right in the width direction from the middle. The auxiliary frame 22 can function as a propeller guard for the rotor 3. For example, in the event of a collision of the aerial vehicle, the auxiliary frame 22 can protect the rotor 3 attached to the motor 4 and the motor 4.

[0016] The rotor 3 is provided on the arm 23 between the end of the auxiliary frame 22 and the support frame 21. In the example shown in Fig. 1, the arm 23 is provided with a motor mount 231, and a motor 4 that provides power to the rotor 3 is provided on the motor mount 231, and the rotor 3 is attached to the motor 4.

[0017] In this embodiment, the arms 23 and the rotors 3 are provided at four locations, namely, front, rear, left and right, but the present invention is not limited to this example. The number of arms 23 and the rotors 3 provided can be changed as appropriate depending on the structure, shape, equipment, size, etc. of the unmanned aerial vehicle 1.

[0018] Furthermore, a camera 5 is provided on the support frame 21 at the connection between the support frame 21 and the auxiliary frame 22 on the front side of the unmanned aerial vehicle 1. The camera 5 can be provided at any location on the support frame 21 in addition to the location shown in FIG. 1. Such a camera 5 may be provided for capturing images from a first person view (FPV) and for capturing images of an inspection target. The support frame 21 and the camera 5 may be connected via a gimbal or the like.

[0019] Next, a description will be given of the hardware configuration of the unmanned aerial vehicle 1. Fig. 2 is a diagram showing an example of the hardware configuration of the unmanned aerial vehicle 1 according to this embodiment. As shown in Fig. 2, the unmanned aerial vehicle 1 includes a flight controller 11, a battery 14, an ESC (Electric Speed ​​Controller) 15, and a transceiver unit 16 in a main body unit 2.

[0020] The flight controller 11 may have one or more processors, such as, for example, a central processing unit (CPU) or a programmable processor such as a field-programmable gate array (FPGA). The flight controller 11 has and has access to a memory 12. The memory 12 stores logic, code, and / or program instructions that the flight controller 11 is able to execute to perform one or more steps.

[0021] The memory 12 may include a separable medium or an external storage device, such as an SD card or a random access memory (RAM). Data acquired from the camera 5 or the sensor 13 may be directly transmitted to and stored in the memory 12. For example, still image and video data captured by the camera 5 is recorded in an internal memory or an external memory.

[0022] Flight controller 11 includes a control module configured to control the state of unmanned aerial vehicle 1. For example, the control module controls motor 4, which is a propulsion mechanism of unmanned aerial vehicle 1, via ESC 15 to adjust the spatial arrangement, speed, and / or acceleration of unmanned aerial vehicle 1, which has six degrees of freedom (translational motion x, y, and z, and rotational motion θx, θy, and θz). The motor 4 rotates rotor 3 to generate lift for the unmanned aerial vehicle 1.

[0023] The flight controller 11 can communicate with a transceiver 16 configured to transmit and / or receive data from one or more external devices (e.g., flight control 17). The transceiver 16 can use any suitable communication means, such as wired or wireless communication. The transceiver 16 can utilize, for example, one or more of a local area network (LAN), a wide area network (WAN), infrared, radio, WiFi, a point-to-point (P2P) network, a telecommunications network, cloud communication, and the like.

[0024] The transceiver 16 can transmit and / or receive one or more of data acquired by the sensor 13, processing results generated by the flight controller 11, predetermined control data, user commands from a terminal or a remote controller, etc. Information acquired by the sensor 13 may be output to a piloting device 17 or the like via the transceiver 16.

[0025] The control device 17 is a device for controlling the control of the flight of the unmanned aerial vehicle 1. The flight of the unmanned aerial vehicle 1 may be controlled by the control of an operator on the ground or the like, or may be controlled by automatic control based on an autonomous flight program using flight path information and sensing. The control device 17 may be, for example, a transceiver (radio transmitter), a smartphone, a tablet, or other terminal.

[0026] The sensor 13 in this embodiment may include, for example, an inertial sensor, an acceleration sensor, a gyro sensor, a GPS sensor, a wind sensor, a temperature sensor, a humidity sensor, an air pressure sensor, an altitude sensor, a proximity sensor such as LiDAR (Laser Imaging Detection and Ranging), or a vision / image sensor other than the camera 5.

[0027] <Testing method> Next, an example of an inspection method for a steelmaking heating furnace using the unmanned aerial vehicle 1 according to the present embodiment will be described. The inspection method here includes an imaging method in the internal space of a heating furnace using the unmanned aerial vehicle 1 in the inspection of the heating furnace. The steelmaking heating furnace in the present embodiment may mainly include, for example, a continuous annealing furnace or a batch annealing furnace. In such an annealing furnace, pipes extending in one direction are installed coarsely and at regular intervals, making this inspection method more useful. The material to be heated or annealed is not particularly limited, and for example, the steel material may be a thin plate (plate or coil), a thick plate, a shaped steel, a wire rod, a bar, a bar, or a steel material after processing / forming. In addition, in the internal space of the heating furnace, the drone flies between two pipes that extend along the horizontal direction and are arranged substantially parallel to each other, and images are taken of the root sides of the two pipes. The pipes here are an example of a structure. The structure is not limited to a pipe, and may be, for example, a furnace wall of the heating furnace or equipment installed in the heating furnace. This structure may be a structure that extends at least in the horizontal direction. "Extending at least horizontally" refers to a structure that extends in at least one horizontal direction, such as a pipe or a wall. The space between structures may be, for example, between a pipe and a furnace wall, between a furnace wall and a furnace wall, between a pipe and another structure, between a furnace wall and another structure, or between other structures. Such a pipe may be, for example, a radiant tube. Since a radiant tube is a heat source provided to heat the inside of a heating furnace, even if the temperature inside the heating furnace drops at the start of the inspection, the radiant tube itself may retain heat, and therefore the airflow around the radiant tube changes significantly, making it difficult to image it using conventional methods. Therefore, according to this inspection method, the accuracy of imaging the radiant tube can be improved in a simple manner. In addition to the two pipes, one or more pipes may be provided. In addition, this inspection method is also applicable to heating furnaces other than those used for steelmaking.

[0028] In addition, in one example of the inspection method according to this embodiment, the flight of the unmanned aerial vehicle 1 is controlled by an operator, but the unmanned aerial vehicle 1 may be controlled to automatically perform at least one of the flight for carrying out the inspection method and the image capturing by the camera 5. In other words, the unmanned aerial vehicle 1 may be controlled by autonomous control.

[0029] 3 is a flow chart showing an example of the flow of the inspection method for an iron-making heating furnace according to this embodiment. First, when the temperature inside the heating furnace has dropped to an appropriate temperature, the unmanned aerial vehicle 1 starts flying (step S101). The unmanned aerial vehicle 1 flies to a position between the first pipe and the second pipe (step S103). The flight path to reach the position between the first pipe and the second pipe is not particularly limited, and other processing may be performed by the unmanned aerial vehicle 1 before reaching this point.

[0030] Next, the unmanned aerial vehicle 1 adjusts the imaging position and imaging direction between the first pipe and the second pipe (step S105). FIG. 4 is a diagram showing a first example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to this embodiment. In FIG. 4, L corresponds to the extension direction of the radiant tube 100A (an example of the first structure) and the radiant tube 100B (an example of the second structure), W corresponds to the juxtaposition direction of the radiant tubes 100A and 100B, and H corresponds to the height direction. In this specification, the horizontal direction means a direction consisting of at least one component of the extension direction L and the juxtaposition direction W. The structure of the radiant tubes 100A and 100B according to this embodiment is not particularly limited, and may be, for example, a straight radiant tube, a U-shaped radiant tube, or an M-shaped radiant tube. The horizontal extension direction of radiant tubes 100A, 100B here means the direction in which the pipes extend from inner wall 101 of the heating furnace based on inner wall 101 (i.e., the direction perpendicular to inner wall 101). In this case, between the first pipe and the second pipe means between two pipes that are installed at approximately the same position in height direction H and are continuously arranged side by side in the juxtaposition direction W. For example, when M-shaped radiant tubes are arranged side by side, if the piping on the burner side of one radiant tube and the piping on the exhaust side of the other radiant tube are arranged side by side at approximately the same height, the space between the first pipe and the second pipe may correspond to the space between the piping on the burner side of one radiant tube and the piping on the exhaust side of the other radiant tube.

[0031] As shown in FIG. 4, the unmanned aerial vehicle 1 is located between the radiant tubes 100A and 100B. The unmanned aerial vehicle 1 is located on one side of the center CT1 in the extension direction L of the radiant tubes 100A and 100B (in this case, the root side of the radiant tubes 100A and 100B). The center CT1 is, for example, a position equivalent to half the length of the shorter of the radiant tubes 100A and 100B in the extension direction L. By setting the center CT1 to a position equivalent to half the length of the shorter of the radiant tubes 100A and 100B, both radiant tubes can be imaged with a narrower angle of view, and imaging processing can be performed efficiently. However, the present technology is not limited to such an example, and the position of the center CT1 may be a position equivalent to half the length of either one of the radiant tubes in the extension direction L. In addition, by positioning the unmanned aerial vehicle 1 on the root side, images of the root side, which are relatively difficult to image, can be obtained with higher quality. In the example shown in Figure 4, radiant tubes 100A and 100B have the same length in extension direction L. In the case shown in Figure 4, one side means the base side (inner wall 101 side) of radiant tubes 100A, 100B. Furthermore, the unmanned aerial vehicle 1 according to this embodiment flies above center CS1 in the juxtaposed direction W of radiant tubes 100A, 100B. Center CS1 is the center position when the surfaces facing each other in the juxtaposed direction W of radiant tubes 100A, 100B are considered to be the ends when viewed from the height direction H.

[0032] In addition, the flight attitude of the unmanned aerial vehicle 1 is controlled so that the reference direction of the imaging direction of the camera 5 (imaging device) of the unmanned aerial vehicle 1 is adjusted to the other side of the radiant tubes 100A, 100B (the opposite side to the one side across the center CT1) along the extension direction L. In the example shown in Fig. 4, the reference direction of the imaging direction of the camera 5 is the direction along the center CS1.

[0033] In this state, it is possible to capture an image of the area between the boundary lines SA1 and SA2 of the angle of view of the camera 5. However, with only this reference direction, the root portions 102A and 102B of the radiant tubes 100A and 100B near the boundary lines SA1 and SA2 are not included in the angle of view or are significantly affected by the lens parameters of the camera 5, and the images of the radiant tubes 100A and 100B included in the captured image may be distorted.

[0034] Next, the unmanned aerial vehicle 1 rotates toward the first piping side (the radiant tube 100A side) and performs imaging processing to generate an image (step S107). First, in the rotation control of the unmanned aerial vehicle 1, the unmanned aerial vehicle 1 is maintained in a state positioned on the one side in the extension direction L. Then, the unmanned aerial vehicle 1 is rotated toward the first piping side, with the imaging direction of the camera 5 being based on the extension direction L of the piping, up to a first maximum angle when facing the radiant tube 100A side. At this time, the unmanned aerial vehicle 1 rotates around the yaw axis (the axis along the height direction H shown in FIG. 4).

[0035] FIG. 5 is a diagram showing a second example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to this embodiment. As shown in FIG. 5, the unmanned aerial vehicle 1 rotates around the yaw axis on the spot so that the imaging direction LA1 of the camera 5 faces the first pipe side. When the unmanned aerial vehicle 1 rotates, as viewed from the height direction H, the position before rotation and the position after rotation on the LW plane can vary slightly as long as they are between the radiant tubes 100A and 100B and are on the inner wall 101 side of the center CT1. The rotation angle of the unmanned aerial vehicle 1 corresponds to the angle formed by the extension direction L and the imaging direction LA1. The maximum value of this rotation angle is the first maximum angle. The first maximum angle is not particularly limited, but for example, when generating an orthoimage consisting of multiple images including the radiant tube 100A, the maximum angle at which the overlap rate can satisfy a predetermined condition is the first maximum angle.

[0036] As shown in Fig. 5, by rotating the unmanned aerial vehicle 1 on the spot around the yaw axis toward the radiant tube 100A, the root portion 102A is included in the center of the angle of view, so that an image without distortion can be obtained. Even in a narrow space such as between the radiant tubes 100A and 100B that is easily affected by air currents, flight control is simple because only rotation control around the yaw axis is required. Furthermore, the continuous structure of the radiant tube 100A can be accurately reflected in the post-processing such as the generation of orthoimages and the generation of information such as point clouds and meshes that constitute a three-dimensional virtual object.

[0037] In addition, the imaging process targeting the radiant tube 100A can be performed appropriately between the initial imaging direction of the unmanned aerial vehicle 1 and the imaging direction at the first maximum angle.

[0038] Next, the unmanned aerial vehicle 1 rotates toward the second piping side (the radiant tube 100B side) and performs imaging processing to generate an image (step S109). First, in controlling the rotation of the unmanned aerial vehicle 1, the unmanned aerial vehicle 1 is maintained in a position on the one side in the extension direction L, as in the case of the radiant tube 100A side. Then, the unmanned aerial vehicle 1 is rotated toward the second piping side, with the second maximum angle being the limit when the imaging direction of the camera 5 faces the radiant tube 100B side, based on the extension direction L of the piping. At this time, the unmanned aerial vehicle 1 rotates around the yaw axis.

[0039] FIG. 6 is a diagram showing a third example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to this embodiment. As shown in FIG. 6, the unmanned aerial vehicle 1 rotates around the yaw axis on the spot so that the imaging direction LA1 of the camera 5 faces the second piping side. The rotation angle of the unmanned aerial vehicle 1 corresponds to the angle between the extension direction L and the imaging direction LA1. The maximum value of this rotation angle is the second maximum angle. The second maximum angle is not particularly limited, but for example, when generating an orthoimage consisting of multiple images including the radiant tube 100B, the maximum angle at which the overlap rate can satisfy a predetermined condition is the second maximum angle.

[0040] As in step S107, by rotating the unmanned aerial vehicle 1 on the spot around the yaw axis toward the radiant tube 100B, the root portion 102B is included in the center of the angle of view, so that an image without distortion can be obtained. Furthermore, even in a narrow space such as between the radiant tubes 100A and 100B, which is easily affected by air currents, only rotation control around the yaw axis is required, so flight control is simple. Furthermore, the continuous structure of the radiant tube 100B can be accurately reflected in the post-processing processes of generating orthoimages and generating point clouds constituting a three-dimensional virtual object. Furthermore, since the imaging process of each radiant tube is performed between the radiant tubes 100A and 100B, the relative positional relationship between the radiant tubes 100A and 100B can be accurately obtained.

[0041] The imaging process for the radiant tube 100A may be performed as appropriate between the initial imaging direction and the imaging direction at the second maximum angle of the unmanned aerial vehicle 1. That is, the unmanned aerial vehicle 1 can perform imaging process as appropriate within the range of imaging directions defined by the first maximum angle and the second maximum angle. In the above example, the rotation angle is defined and controlled as the first maximum angle and the second maximum angle as the maximum value of the rotation angle around the yaw axis of the unmanned aerial vehicle 1 in the imaging of the radiant tubes 100A and 100B, respectively, but the present technology is not limited to such an example. For example, the unmanned aerial vehicle 1 may be controlled to rotate around the yaw axis at such an imaging position without any particular restriction. However, by setting at least one of the first maximum angle and the second maximum angle in advance, it is possible to achieve both maximization of the amount of information obtained by imaging and efficiency in the imaging process.

[0042] When the imaging is completed, the inspection method ends. The obtained captured images can be used, for example, to generate an ortho-image including the radiant tubes 100A and 100B, or to generate information on a point cloud constituting a three-dimensional virtual object that mimics the radiant tubes 100A and 100B.

[0043] Thus, in the inspection method according to this embodiment, the unmanned aerial vehicle 1 flies between two pipes arranged side by side in approximately parallel fashion, and takes images while rotating around the yaw axis in a position based on a state in which the unmanned aerial vehicle 1 is positioned on one side in the extension direction L of the pipes and facing the other side. This makes it possible to obtain highly accurate images of the area around the pipes while minimizing the effect of airflow around the pipes on the flight control of the unmanned aerial vehicle 1.

[0044] In this embodiment, the unmanned aerial vehicle 1 is flown to a position where the root side in the extension direction L of the radiant tubes 100A, 100B is on one side, but the present technology is not limited to this example. For example, the unmanned aerial vehicle 1 may be flown to a position where the tip side in the extension direction L of the radiant tubes 100A, 100B is on one side, and imaging may be performed from this position toward the inner wall 101 of the heating furnace. In other embodiments, only one of the radiant tubes 100A and 100B may be the imaging target.

[0045] Next, a modified example of this embodiment will be described. In the above embodiment, the rotation control of the unmanned aerial vehicle 1 toward the radiant tubes 100A and 100B is performed around the yaw axis direction at the initial position of the unmanned aerial vehicle 1, but the present technology is not limited to this example.

[0046] FIG. 7 is a diagram showing an example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the first modified example of this embodiment. In the example shown in FIG. 7, the imaging direction of the camera 5 of the unmanned aerial vehicle 1 is the radiant tube 100A side. In this modified example, when the camera 5 of the unmanned aerial vehicle 1 faces the radiant tube 100A side, the imaging position of the unmanned aerial vehicle 1 is closer to the radiant tube 100B than the radiant tube 100A when viewed from the height direction H. In other words, the rotation center position of the unmanned aerial vehicle 1 around the yaw axis is closer to the radiant tube 100B side than the center CS1. In this state, the unmanned aerial vehicle 1 rotates around the yaw axis and moves along the parallel arrangement direction W toward the radiant tube 100B side.

[0047] In the example shown in FIG. 7, the unmanned aerial vehicle 1 is slightly farther away than the radiant tube 100A compared to the example shown in FIG. 5. Therefore, the area of ​​the radiant tube 100A that falls within the angle of view of the camera 5 increases. This allows the radiant tube 100A, which is the subject of the image, to be imaged to be captured reliably. In addition, the influence of the lens parameters can be further suppressed. Note that when imaging while facing the radiant tube 100B side, the same effect can be obtained by moving the position of the unmanned aerial vehicle 1 closer to the radiant tube 100A side.

[0048] Next, a second modified example of this embodiment will be described. In the above embodiment, an example in which the unmanned aerial vehicle 1 flies between the pipes and images each of the pipes are described, but the present technology is not limited to such an example. FIG. 8 is a diagram showing an example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the second modified example of this embodiment. In the example shown in FIG. 8, the unmanned aerial vehicle 1 images each of the pipe 100A and the furnace wall 101B while flying between the pipe 100A and the furnace wall 101B. The unmanned aerial vehicle 1 images each of the pipe 100A and the furnace wall 101B while rotating around the yaw axis along the rotation direction R1 so as to face each of the pipe 100A and the furnace wall 101B. The flight method of the unmanned aerial vehicle 1 and the imaging method by the camera 5 are the same as those of the above embodiment. In this way, the imaging target by the camera 5 of the unmanned aerial vehicle 1 is not limited to the pipes and the like. In such a case, even in an area where the flight of the unmanned aerial vehicle 1 is difficult to stabilize, such as near the furnace wall 101B, it is possible to obtain an image of the furnace wall 101B with high accuracy.

[0049] Although the preferred embodiment of the present disclosure has been described in detail above with reference to the attached drawings, the technical scope of the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field of the present disclosure can conceive of various modified or amended examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0050] In addition, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology according to the present disclosure may achieve other effects that are apparent to a person skilled in the art from the description of this specification, in addition to or in place of the above effects.

[0051] Note that the following configurations also fall within the technical scope of the present disclosure. (Item 1) A method for inspecting an iron-making heating furnace, the method comprising the steps of: imaging an internal space of the iron-making heating furnace, the internal space having a plurality of structures arranged substantially parallel to one another along a horizontal direction, using an unmanned aerial vehicle; The unmanned aerial vehicle is equipped with an imaging device, Flying the unmanned aerial vehicle between a first structure and a second structure among the plurality of structures; With the unmanned aerial vehicle positioned on one side of the structure in the horizontal extension direction, adjusting the reference direction of the imaging direction of the imaging device to the other side of the structure and along the extension direction of the structure; Rotating the unmanned aerial vehicle around a yaw axis while maintaining the unmanned aerial vehicle at the position on one side; generating an image by the imaging device of the unmanned aerial vehicle in at least one of a state in which the imaging direction of the imaging device of the unmanned aerial vehicle faces the first structure side from the reference direction and a state in which the imaging direction faces the second structure side from the reference direction; A method for inspecting a heating furnace for steel making, comprising: (Item 2) An inspection method for an iron-making heating furnace as described in Item 1, wherein, when the imaging direction of the imaging device of the unmanned aerial vehicle is facing one structure side, the unmanned aerial vehicle is close to the other structure side different from the one structure side between each of the structures. (Item 3) 3. The method for inspecting a steel-making heating furnace according to claim 1 or 2, wherein the captured image is used for at least one of generating an orthoimage corresponding to the first structure and the second structure and generating information for acquiring a three-dimensional virtual object. (Item 4) An inspection method for an iron-making heating furnace described in any one of items 1 to 3, which includes positioning the unmanned aerial vehicle on one side of the structure in the horizontal extension direction of the structure, on a side of the center of either shorter side of the structure. (Item 5) An inspection method for an iron-making heating furnace described in any one of items 1 to 4, comprising: while maintaining the unmanned aerial vehicle at the position on one side, rotating the unmanned aerial vehicle around a yaw axis between a first maximum angle based on the reference direction when the imaging direction of the imaging device is facing the first structure, and a second maximum angle based on the reference direction when the imaging direction of the imaging device is facing the second structure, with the extension direction of the structure as a reference in the horizontal direction. (Item 6) 6. The method for inspecting an iron-making heating furnace according to any one of items 1 to 5, wherein the structure includes a radiant tube. (Item 7) 7. The method for inspecting an iron-making heating furnace according to claim 1, wherein the structure includes a furnace wall of the iron-making heating furnace. (Item 8) 8. The method for inspecting an iron-making heating furnace according to any one of items 1 to 7, wherein the iron-making heating furnace includes a continuous annealing furnace or a batch annealing furnace. (Item 9) 9. The method for inspecting an iron-making heating furnace according to any one of items 1 to 8, wherein the unmanned aerial vehicle performs at least one of flying and imaging by autonomous control. [Explanation of symbols]

[0052] 1 Unmanned Aerial Vehicle 2 Main unit 3 Rotor 5. Camera 100A, B Radiant tube

Claims

1. A method for inspecting an iron-making heating furnace, the method comprising the steps of: imaging an internal space of the iron-making heating furnace, the internal space of which has a plurality of structures arranged substantially parallel to one another and extending along a horizontal direction, using an unmanned aerial vehicle; The unmanned aerial vehicle is equipped with an imaging device, flying the unmanned aerial vehicle between a first structure and a second structure among the plurality of structures; With the unmanned aerial vehicle positioned at the base side in the extension direction of the structure extending from the base to the tip, adjusting the reference direction of the imaging direction of the imaging device to be the tip side of the structure and along the extension direction of the structure; After adjusting the reference direction of the imaging device, rotating the unmanned aerial vehicle around a yaw axis while maintaining the unmanned aerial vehicle at the base side position; generating an image by the imaging device of the unmanned aerial vehicle in at least one of a state in which the imaging direction of the imaging device of the unmanned aerial vehicle is oriented toward the first structure side relative to the reference direction and a state in which the imaging direction is oriented toward the second structure side relative to the reference direction due to rotation around the yaw axis; A method for inspecting a heating furnace for steel making, comprising:

2. A method for inspecting a steelmaking heating furnace as described in claim 1, wherein the unmanned aerial vehicle performs flight by autonomous control.

3. An inspection method for an iron-making heating furnace as described in claim 1 or 2, wherein when the imaging direction of the imaging device of the unmanned aerial vehicle is directed toward one of the structures and an image is generated by the imaging device of the unmanned aerial vehicle, the unmanned aerial vehicle is located between each of the structures, close to the other structure side different from the one structure side.

4. The method for inspecting an iron-making heating furnace according to any one of claims 1 to 3, wherein the captured image is used for at least one of generating an orthoimage corresponding to the first structure and the second structure and generating information for obtaining a three-dimensional virtual object.

5. An inspection method for an iron-making heating furnace as described in any one of claims 1 to 4, which includes positioning the unmanned aerial vehicle on the root side of the structure in the extension direction of the structure, further comprising positioning the unmanned aerial vehicle on the root side of the center of the shorter side of the structures.

6. A method for inspecting an iron-making heating furnace as described in any one of claims 1 to 5, comprising rotating the unmanned aerial vehicle around a yaw axis between a first maximum angle based on the reference direction when the imaging direction of the imaging device is facing the first structure, and a second maximum angle based on the reference direction when the imaging direction of the imaging device is facing the second structure, with the extension direction of the structure as a reference in the horizontal direction, while maintaining the unmanned aerial vehicle at the base side position.

7. The method for inspecting an iron-making heating furnace according to any one of claims 1 to 6, wherein the structure includes a radiant tube.

8. The method for inspecting an iron-making heating furnace according to any one of claims 1 to 7, wherein the structure includes a furnace wall of the iron-making heating furnace.

9. The method for inspecting an iron-making heating furnace according to any one of claims 1 to 8, wherein the iron-making heating furnace includes a continuous annealing furnace or a batch annealing furnace.

10. The method for inspecting an iron-making heating furnace according to any one of claims 1 to 9, wherein the unmanned aerial vehicle performs imaging by autonomous control.

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