JP7612149B2 - Inspection method for steelmaking heating furnaces - Google Patents

Description

This disclosure relates to a method for inspecting a steelmaking heating furnace.

There is a demand for reducing the number of people required and shortening the time required for inspections of steelmaking heating furnaces, such as continuous annealing furnaces and batch annealing furnaces. Because heating furnaces are hot immediately after operation has been 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 carry out inspections so that inspections can be started sooner than if personnel were to work in the furnace.

For example, Patent Document 1 discloses a technology for inspecting furnace walls inside 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 and model the structure inside the furnace.

JP 2018-127049 A

In the interior space of a steelmaking heating furnace, when the temperature is high, the influence of the air currents inside is large. In particular, around narrow spaces of structures such as pipes, the structure itself is also affected by the heat, and the structure is easily affected by the air currents, making it difficult to maintain a stable posture when taking images using a drone. In such structures, the resolution of the captured image at the base of the structure is prone to variations in density, making it difficult to obtain highly accurate images.

Therefore, this disclosure has been made in consideration of the above problems, and its purpose is to provide an inspection method for a steelmaking heating furnace that can perform imaging processing around narrow spaces in the structure with high accuracy.

According to the present disclosure, there is provided a method for inspecting an iron-making heating furnace, in which an image of an internal space of the iron-making heating furnace, in which a plurality of structures are arranged substantially parallel to one another along a horizontal direction, is captured using an unmanned aerial vehicle, the unmanned aerial vehicle being provided with an imaging device, the method including: flying the unmanned aerial vehicle between a first structure and a second structure among the plurality of structures; adjusting the reference direction of the imaging direction of the imaging device to a direction along the extension direction of the structure on the other side of the structure while the unmanned aerial vehicle is positioned on one side of the structure in the horizontal extension direction; rotating the unmanned aerial vehicle around a yaw axis while the unmanned aerial vehicle is maintained at the position on the one side; and generating an image using 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 of the imaging device of the unmanned aerial vehicle faces the second structure side from the reference direction.

This disclosure makes it possible to perform imaging processing of the base side around narrow spaces in a structure with high accuracy.

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. A diagram showing an example of the hardware configuration of the unmanned aerial vehicle 1 according to the same embodiment. 4 is a flowchart showing an example of a flow of an inspection method for an iron-making heating furnace according to the embodiment. A figure showing a first example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the same embodiment. A figure showing a second example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the same embodiment. A figure showing a third example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to the same embodiment. A figure showing an example of an imaging position and imaging direction of an unmanned aerial vehicle 1 relating to a first modified example of the same embodiment. A figure showing an example of an imaging position and imaging direction of an unmanned aerial vehicle 1 relating to a second modified example of the same embodiment.

A preferred embodiment of the present disclosure will be described in detail below with reference to the attached drawings. Note that in this specification and drawings, components having substantially the same functional configuration are designated by the same reference numerals to avoid redundant description.

<Example of unmanned aerial vehicle configuration>
Fig. 1 is a perspective view showing an example of the configuration 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.

As shown in FIG. 1, the unmanned aerial vehicle 1 according to this embodiment comprises 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.

More specifically, the main body 2 is composed 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.

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, flight controller, or 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 below), and the flight controller controls the rotation speed of the motor 24, etc.

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 fore-and-aft direction from the fore-and-aft ends of the support frame 21, and extends 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.

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, which is provided with a motor 4 that provides power to the rotor 3, and the rotor 3 is attached to the motor 4.

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

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 imaging from a first person view (FPV) and for imaging the inspection target. The support frame 21 and the camera 5 may be connected via a gimbal or the like.

Next, the hardware configuration of the unmanned aerial vehicle 1 will be described. 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 the main body unit 2.

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 can execute to perform one or more steps.

The memory 12 may include, for example, a separable medium such as an SD card or a random access memory (RAM) or an external storage device. 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 the built-in memory or an external memory.

The flight controller 11 includes a control module configured to control the state of the unmanned aerial vehicle 1. For example, the control module controls the motor 4, which is the propulsion mechanism of the unmanned aerial vehicle 1, via the ESC 15 to adjust the spatial arrangement, speed, and/or acceleration of the 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 the rotor 3, generating lift for the unmanned aerial vehicle 1.

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., piloting device 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, etc.

The transceiver 16 can transmit and/or receive one or more of the following: 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, etc. via the transceiver 16.

The control device 17 is a device for controlling the flight of the unmanned aerial vehicle 1. The flight of the unmanned aerial vehicle 1 may be controlled by an operator on the ground, etc., 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.

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, a barometric 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.

<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, the pipes extending in one direction are arranged 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 inspection method, 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 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 the radiant tube is a heat source provided to heat the inside of the 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 can be applied to heating furnaces other than those used for steelmaking.

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 and the image capture by the camera 5 to carry out the inspection method. In other words, the unmanned aerial vehicle 1 may be controlled autonomously.

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

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 the radiant tubes 100A and 100B here means the direction in which the pipes extend from the inner wall 101 of the heating furnace (i.e., the direction perpendicular to the inner wall 101). In this case, the space between the first pipe and the second pipe means the space between two pipes that are installed at approximately the same position in the height direction H and are continuously arranged side by side in the arrangement direction W. For example, when M-type radiant tubes are arranged side by side, if the pipe on the burner side of one radiant tube and the pipe 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 pipe on the burner side of one radiant tube and the pipe on the exhaust side of the other radiant tube.

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 positioning the center CT1 at 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 image 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 at 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 FIG. 4, the lengths of radiant tubes 100A and 100B in the extension direction L are the same. In the case shown in FIG. 4, one side means the base side (inner wall 101 side) of radiant tubes 100A and 100B. Furthermore, the unmanned aerial vehicle 1 according to this embodiment flies above center CS1 in the parallel arrangement direction W of radiant tubes 100A and 100B. Center CS1 is the center position when the surfaces facing each other in the parallel arrangement direction W of radiant tubes 100A and 100B are considered to be the ends when viewed from the height direction H.

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 from the one side across the center CT1) along the extension direction L. In the example shown in Figure 4, the reference direction of the imaging direction of the camera 5 is the direction along the center CS1.

In this state, the area between the boundary lines SA1 and SA2 of the angle of view of the camera 5 can be captured. 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, which can cause distortion in the images of the radiant tubes 100A and 100B included in the captured image.

Then, the unmanned aerial vehicle 1 rotates to the first piping side (the radiant tube 100A side) and performs imaging processing to generate an image (step S107). 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. Then, the unmanned aerial vehicle 1 is rotated to the first piping side with the imaging direction of the camera 5 being based on the extension direction L of the piping, with the first maximum angle being the limit 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 Figure 4).

Figure 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 Figure 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 between 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.

As shown in FIG. 5, by rotating the unmanned aerial vehicle 1 on the spot around the yaw axis towards the radiant tube 100A, the root portion 102A is included in the central portion of the angle of view, so that an undistorted captured image can be obtained. Even in a narrow space such as between 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 processes of generating orthoimages and generating information such as point clouds and meshes that constitute three-dimensional virtual objects.

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.

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 above-mentioned one side in the extension direction L, as with 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.

Figure 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 Figure 6, the unmanned aerial vehicle 1 rotates on the spot around the yaw axis 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 specified condition is the second maximum angle.

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, and an image without distortion can be obtained. Furthermore, even in a narrow space such as between 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 that constitute three-dimensional virtual objects. Furthermore, since imaging processing of each radiant tube is performed between radiant tubes 100A and 100B, the relative positional relationship between radiant tubes 100A and 100B can be obtained with high accuracy.

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. In other words, 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 imaging 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 restrictions. However, by setting at least one of the first maximum angle and the second maximum angle in advance, it is possible to maximize the amount of information obtained by imaging and to improve the efficiency of the imaging process.

When the imaging is complete, the inspection method ends. The captured image can be used, for example, to generate an orthoimage that includes the radiant tubes 100A, 100B, or to generate point cloud information that constitutes a three-dimensional virtual object that mimics the radiant tubes 100A, 100B.

In this way, 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 from a position on one side of the pipes in the extension direction L and facing the other side as a reference. 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.

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 subject of imaging.

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 this technology is not limited to such an example.

Figure 7 is a diagram showing an example of the imaging position and imaging direction of the unmanned aerial vehicle 1 according to a first modified example of this embodiment. In the example shown in Figure 7, the imaging direction of the camera 5 of the unmanned aerial vehicle 1 is toward 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 radiant tube 100B than to radiant tube 100A when viewed from the height direction H. In other words, the position of the center of rotation around the yaw axis of the unmanned aerial vehicle 1 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 direction W toward the radiant tube 100B side.

In the example shown in Figure 7, the unmanned aerial vehicle 1 is slightly farther away than the radiant tube 100A compared to the example shown in Figure 5. This increases the area of the radiant tube 100A that falls within the angle of view of the camera 5. 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.

Next, a second modified example of this embodiment will be described. In the above embodiment, an example in which the unmanned aerial vehicle 1 is flown between the pipes to capture images of each pipe, 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 captures images 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 captures images with the camera 5 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 in the above embodiment. In this way, the subject to be imaged by the camera 5 of the unmanned aerial vehicle 1 is not limited to the pipes, etc. 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.

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 with ordinary knowledge in the technical field of the present disclosure can conceive of various modified or revised examples within the scope of the technical ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present disclosure.

Furthermore, the effects described in this specification are merely descriptive or exemplary and are not limiting. In other words, the technology disclosed herein may achieve other effects that are apparent to a person skilled in the art from the description in this specification, in addition to or in place of the above effects.

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 an iron-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 the 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)
The method for inspecting an iron-making heating furnace according to any one of claims 1 to 6, wherein the structure includes a furnace wall of the iron-making heating furnace.
(Item 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. A 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 photographing under autonomous control.

Reference Signs List 1 Unmanned aerial vehicle 2 Main body 3 Rotor 5 Camera 100A, B Radiant tube

Claims (10)

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: The method for inspecting an iron-making heating furnace according to claim 1 , wherein the unmanned aerial vehicle performs flight under autonomous control . 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. 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 acquiring a three-dimensional virtual object. 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, the unmanned aerial vehicle being positioned on the root side of the center of the shorter side of the structures . 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. 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. 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. 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. 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.

Images