Step cover

Abstract

To provide a step cover in which a flying body can autonomously flight inside a structure smoothly.SOLUTION: A step cover 1 is provided in an ascend / descend portion 24 in which there are formed a plurality of steps 23 protruding from an inner wall face 22 of a structure 2 having a space where a flying body 4 autonomously flights inside. The step cover 1 comprises: a cover portion 11 bridged between an upper step 23a on the uppermost stage and a lower step 23b on the lowermost stage among the plurality of steps 23 and covering the ascend / descend portion 24; and an upper attachment portion 12 provided at an upper end of the cover portion 11 and attached to the upper step 23a. The upper attachment portion 12 can be installed on the ascend / descend portion 24 from above.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a step cover. [Background technology]

[0002] In recent years, technology for autonomously flying unmanned aerial vehicles such as drones has been under study. For example, the drone described in Patent Document 1 identifies its own position in a water treatment plant by radio waves transmitted from a Global Navigation Satellite System (GNSS) such as a Global Positioning System (GPS) and flies autonomously along a flight route based on a patrol inspection plan. It is desirable for autonomously flying unmanned aerial vehicles to be used for inspection work in places that are likely to be dangerous when inspected manually, such as communication manholes, sewer pipe facilities, and the inside of structures such as boilers and chimneys, so that inspection work can be performed safely without the risk of personal injury during inspection. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-164751 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the interior of manholes, sewer pipe facilities, boilers, chimneys, and other structures, steps have often been provided protruding from the wall to allow workers performing inspection work to enter and exit the area connecting the ground and the interior. When an unmanned aerial vehicle flies inside a structure, the flight area is narrowed by the steps, and the unmanned aerial vehicle may come into contact with or get caught in the steps, making it impossible to fly, which poses a problem of difficulty in controlling flight.

[0005] In consideration of the above circumstances, an object of the present invention is to provide a step cover that enables an aircraft to fly smoothly and autonomously inside a structure. [Means for solving the problem]

[0006] One aspect of the present invention is a step cover provided on a lifting section in which a plurality of steps are formed protruding from an inner wall surface of a structure having a space inside in which an aircraft flies autonomously, the step cover comprising: a cover section that is installed between the highest upper step and the lowest lower step of the plurality of steps and covers the lifting section; and an upper mounting section that is provided at an upper end of the cover section and attached to the upper step, the step cover being configured so that the upper mounting section can be installed on the lifting section from above.

[0007] Another aspect of the present invention is the step cover described above, wherein the upper mounting portion has a hook shape that engages with the upper step from above.

[0008] Another aspect of the present invention is the above-mentioned step cover, further comprising a lower mounting portion provided at a lower end of the cover portion and attached to the lower step.

[0009] In addition, one aspect of the present invention is the above-mentioned step cover, wherein the cover portion or the lower mounting portion is provided with an expansion / contraction portion.

[0010] In addition, one aspect of the present invention is the above-mentioned step cover, further comprising an upper guide portion that slopes upward from an upper end of the cover portion toward the inner wall surface.

[0011] In addition, one aspect of the present invention is the above-mentioned step cover, further comprising a lower guide portion that slopes downward from a lower end of the cover portion toward the inner wall surface.

[0012] Another aspect of the present invention is the step cover described above, wherein the cover portion is configured of a soft planar member.

[0013] Another aspect of the present invention is the above-mentioned step cover, wherein the cover portion is configured such that a plurality of linear members extending vertically are aligned and fixed to an upper end portion of the cover portion.

[0014] In one aspect of the present invention, in the step cover, the lateral length of the cover portion is longer than the width of the tread of the step.

[0015] Another aspect of the present invention is the step cover described above, wherein the cover portion covers corner portions at both ends in the width direction of the tread of the step.

[0016] Another aspect of the present invention is the step cover described above, wherein the cover portion is provided at a lower end with a position marker that can be detected by the flying object.

[0017] Another aspect of the present invention is the step cover described above, wherein the cover portion is provided with a height marker that indicates a height position and is detectable by the flying object. Effect of the Invention

[0018] The present invention enables an aircraft to fly smoothly and autonomously inside a structure. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic diagram showing an overall configuration of a structure 2 to which a step cover 1 according to a first embodiment of the present invention is applied. [Diagram 2] 1 is a schematic diagram showing an installation state of a step cover 1 according to a first embodiment of the present invention. [Diagram 3] 1A is a side view showing the mounting state of the step cover 1 according to the first embodiment of the present invention, and FIG. 1B is a top view showing the mounting state of the step cover 1. [Figure 4] FIG. 11 is a schematic diagram showing an installation state of a step cover 1 according to a second embodiment of the present invention. [Diagram 5] FIG. 11 is a schematic diagram showing an installation state of a step cover 1 according to a third embodiment of the present invention. [Figure 6] FIG. 11 is a schematic diagram showing an installation state of a step cover 1 according to a fourth embodiment of the present invention. [Figure 7] FIG. 11 is a schematic diagram showing an installation state of a step cover 1 according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <First embodiment> Hereinafter, a step cover 1 according to a first embodiment of the present invention will be described with reference to the drawings.

[0021] 1 is a schematic diagram showing the overall configuration of a structure 2 to which a step cover 1 according to a first embodiment of the present invention is applied. The structure 2 is a manhole neck that connects a piping section 3 installed underground and having a communication cable laid therein with the ground. The manhole neck 2 is an example of a structure.

[0022] The aircraft 4 inspecting the inside of the piping section 3 enters the manhole neck 2 from the ground through the manhole opening 21, passes through the manhole neck 2 to reach the piping section 3, and when exiting the piping section 3, passes through the manhole neck 2 to exit onto the ground. The aircraft 4 is equipped with an upper camera 41 capable of capturing an image of the upper part of the aircraft 4, and a side camera 42 capable of capturing an image of the left and right parts of the aircraft 4.

[0023] The manhole neck 2 is a hole excavated vertically from the ground, or a tubular structure that is circular in plan view and installed along the inner wall of the hole. The manhole neck 2 is not limited to the above configuration, and may be provided at an angle to the ground, or may be a prismatic structure that is rectangular in plan view.

[0024] Manhole neck 2 protrudes horizontally into the pipe from inner wall surface 22, and is provided with a plurality of steps 23 that are installed at equal intervals vertically from the ground from the upper end to the lower end of manhole neck 2. The plurality of steps 23 form an elevation section 24 that allows an operator to ascend and descend manhole neck 2 to access piping section 3 from the ground or access piping section 3 from the ground.

[0025] The step 23 has a first protruding portion 231, a second protruding portion 232, and a tread 233. The first protruding portion 231 and the second protruding portion 232 protrude from the inner wall surface 22 in a horizontal direction when viewed from the side. The first protruding portion 231 and the second protruding portion 232 protrude parallel to each other and have approximately the same length. The tread 233 connects the first protruding portion 231 and the second protruding portion 232 in an approximately horizontal direction, and is a portion on which a person places his or her hands and feet when ascending or descending. The multiple steps 23 have the same shape and are formed at intervals in the vertical direction. In the following description, the extension direction of the tread 233 may be referred to as the width direction of the step 23.

[0026] As shown in Figs. 2 and 3, the step cover 1 is used to protect the flying object 4 and the lifting section 24 from contact between the flying object 4 and the lifting section 24 when the flying object 4 passes through the manhole neck 2, and to ensure smooth flight of the flying object 4. The step cover 1 includes a cover section 11, an upper mounting section 12, a lower mounting section 13, an upper guide section 14, a lower guide section 15, a position marker 16, and a height marker 17. The step cover 1 is installed between the uppermost step 23a (upper step) and the lowermost step 23b (lower step) of the multiple steps 23 that form the lifting section 24. The step cover 1 is provided so as to cover the treads 233 of each step 23 with respect to the central section 241 of the manhole neck 2 in a plan view.

[0027] The cover part 11 includes a linear cover 111, a cover upper end 112, and a cover lower end 113. The linear cover 111 has a plurality of linear members extending vertically, which are fixed in a line in the width direction of the step 23 between the cover upper end 112 and the cover lower end 113. A plurality of linear covers 111 are provided at equal intervals in the extension direction of the step bar 233. The cover upper end 112 and the cover lower end 113 are connected to the plurality of linear covers 111 and extend in the extension direction of the step bar 233. Since the linear cover 111 is made of a plurality of soft linear members, it can be folded compactly when the step cover 1 is removed, for example, when the lifting part 24 is used. In addition, the step cover 1 can be easily stored when not in use. The linear members of the linear cover 111 are not limited to being inserted at equal intervals, but may be provided at intervals in the extension direction of the step bar 233.

[0028] The cover upper end portion 112 is connected to the upper end of the linear cover 111 and is adjacent to the uppermost step 23a. The length of the cover upper end portion 112 in the width direction is longer than the length of the step bar 233 in the width direction.

[0029] The cover lower end 113 is connected to the lower end of the linear cover 111 and is adjacent to the lowest step 23b. The width direction length of the cover lower end 113 is longer than the width direction length of the step 233 and approximately matches the width direction length of the cover upper end 112.

[0030] The multiple linear covers 111 are arranged such that both widthwise ends 111a, 111b of the step bar 233 are located at both widthwise ends 112a, 112b of the step bar 233 of the cover upper end 112 and at both widthwise ends 113a, 113b of the cover lower end 113. Therefore, the cover portion 11 is a blind-like cover provided to cover the step bar 233 of each step 23 up to both widthwise ends 233a, 233b of the step bar 233 with respect to the central portion 241 in a plan view.

[0031] The intervals between the multiple linear covers 111 are long enough to prevent parts of the flying object 4 from entering between the multiple linear covers 111 and coming into contact with parts of the lifting section 24. There are no limitations on the material, shape, etc. of the multiple linear covers 111, as long as they do not cause parts of the flying object 4 to come into contact with parts of the lifting section 24. For example, the linear covers 111 may be configured such that multiple chain-, string-, rod-, bellows-, or band-shaped thin plate members are provided in the extension direction of the step bars 233.

[0032] The upper mounting portion 12 is connected to the cover upper end portion 112 and is formed in a hook shape that engages with the uppermost step 23a from above. The upper mounting portion 12 is formed with a length that approximately matches the distance between the first protruding portion 231 and the second protruding portion 232. The upper mounting portion 12 only needs to be engaged with the uppermost step 23a so as to be able to support the cover portion 11, and the width of the upper mounting portion 12 may be shorter than the distance between the first protruding portion 231 and the second protruding portion 232.

[0033] The lower mounting portion 13 is connected to the cover lower end portion 113 and is formed in a hook shape that engages with the lowest step 23b from below. The lower mounting portion 13 is formed with a length that approximately matches the distance between the first protruding portion 231 and the second protruding portion 232. The lower mounting portion 13 only needs to be engaged with the lowest step 23b so as to be able to hold the cover portion 11, and the width of the lower mounting portion 13 may be shorter than the distance between the first protruding portion 231 and the second protruding portion 232.

[0034] The step cover 1 is configured so as to be installable on the lift section 24 by engaging the upper mounting section 12 with the uppermost step 23a from above and the lower mounting section 13 with the lowermost step 23b from below.

[0035] The plurality of linear covers 111 are elastic. When the step cover 1 is installed on the lifting section 24 via the upper mounting section 12 and the lower mounting section 13, the upper mounting section 12 is first engaged with the uppermost step 23a from above, and the lower mounting section 13 is lowered to the height where the lowermost step 23b of the manhole neck 2 is located. For example, the lower mounting section 13 arranged at the height of the lowermost step 23b is engaged with the lowermost step 23b from below using a tool capable of reaching the height of the lowermost step 23b, such as an elastic rod-shaped member. The above method allows the step cover 1 to be easily attached to the lifting section 24 by a single worker. As long as the step cover 1 can be easily attached to the lifting section 24, the elastic parts are not limited to the plurality of linear covers 111. For example, the lower mounting section 13 may be elastic. As long as the step cover 1 can be installed on the lifting section 24 via the upper mounting section 12 and the lower mounting section 13, the installation method is not limited to the above. For example, the lower mounting portion 13 may be first engaged, and then the cover portion 11 may be expanded or contracted by the expanding portion to engage the upper mounting portion 12.

[0036] The upper guide portion 14 is formed so as to incline upward from the cover upper end portion 112 toward the inner wall surface 22. The upper guide portion 14, the uppermost step 23a, and the manhole neck portion 2 form a right-angled triangular shape in a side view, with the upper guide portion 14 being provided so as to be the hypotenuse. The upper guide portion 14 is formed so as to cover the step 23 between the inner wall surface 22 and the step cover 1 in a plan view so that no gap is generated in a plan view between the cover upper end portion 112 and the inner wall surface 22. The upper guide portion 14 is inclined to prevent the flying object 4 from contacting the step portion protruding from the inner wall surface 22 of the uppermost step 23a. The upper guide portion 14 is connected to the cover upper end portion 112 and provided integrally with the cover portion 11.

[0037] The lower guide portion 15 is formed so as to incline downward from the cover lower end portion 113 toward the inner wall surface 22. The lower guide portion 15, the lowermost step 23b, and the manhole neck portion 2 form a right-angled triangle in side view, with the lower guide portion 15 being provided as the hypotenuse. The lower guide portion 15 is formed so that there is no gap between the cover lower end portion 113 and the inner wall surface 22 in plan view. The lower guide portion 15 is connected to the cover lower end portion 113, and provided integrally with the cover portion 11.

[0038] The upper guide portion 14 and the lower guide portion 15 are formed of a resin material with a small coefficient of friction, such as Teflon (registered trademark). The upper guide portion 14 and the lower guide portion 15 are not limited to the above configuration as long as the coefficient of friction is small, and may be formed of a metal material with a mirror-finished surface, for example. The upper guide portion 14 and the lower guide portion 15 each have a double-sided tape portion 14a and 15a having adhesiveness on both sides at the tip portion connecting to the inner wall surface 22. The double-sided tape portions 14a and 15a are poked toward the adhesive portions 22a and 22b of the inner wall surface 22 with a rod-shaped object to adhere them. The adhesion of the upper guide portion 14 and the lower guide portion 15 to the inner wall surface 22 with the double-sided tape portions 14a and 15a prevents the step cover 1 from being rolled up by external forces such as wind generated by the driving of the propeller of the aircraft 4. The upper guide portion 14 and the lower guide portion 15 have a straight line shape, but are not limited to the above configuration as long as the flying object 4 can be prevented from coming into contact with and getting caught on the upper guide portion 14 and the lower guide portion 15, and may be formed, for example, into a convex curved shape when viewed from the side having an R shape.

[0039] In this embodiment, the cover portion 11 is formed integrally with the upper guide portion 14 and the lower guide portion 15, and therefore the material of the cover portion 11 is the same as that of the upper guide portion 14 and the lower guide portion 15.

[0040] The position marker 16 is provided on the underside 113c of the cover lower end 113 of the cover section 11 in order to recognize the opening position of the manhole neck 2, for example, when the flying object 4 enters the piping section 3 to perform an inspection and returns to the ground. The position marker 16 is a printed figure, a QR code (registered trademark), or the like. The position marker 16 is not limited to the above configuration as long as the flying object 4 can be detected from the piping section 3. For example, a sensor or light-emitting unit capable of detecting the flying object 4 may be provided on the underside 113c of the cover lower end 113.

[0041] When flying over the piping section 3, the aircraft 4 visually recognizes the position marker 16 with the upper camera 41, detects position information, and identifies the position of the manhole neck 2. The method of identifying the position of the manhole neck 2 is not limited to the above configuration, and may be, for example, a method in which a worker on the ground identifies the position of the manhole neck 2 based on image information of the position marker 16 sent from the aircraft 4, or a method in which the aircraft 4 is equipped with AI and the aircraft 4 automatically identifies the position based on image information of the position marker 16.

[0042] The height markers 17 are provided on the linear cover 111 so that the flying object 4 flying inside the manhole neck 2 can recognize its position inside the manhole neck 2. The height markers 17 are scales printed on the surface of the linear cover 111 facing the center 241 in a plan view. The height markers 17 are not limited to the above configuration as long as the flying object 4 can be detected while flying inside the manhole neck 2. For example, the height markers 17 may be symbols printed at regular height intervals.

[0043] When flying inside the manhole neck 2, the aircraft 4 visually recognizes the height markers 17 with the side camera 42 to detect position information, and determines the position of the aircraft 4 inside the manhole neck 2 and the distance to the aboveground part or piping part 3. The method of determining the position and distance is not limited to the above configuration, and may be, for example, a method in which a ground worker determines the position based on image information of the height markers 17 sent from the aircraft 4, or a method in which the aircraft 4 is equipped with AI and the aircraft 4 automatically determines the position based on image information of the height markers 17.

[0044] The aircraft 4 flies autonomously and further includes an inspection camera 43 that captures images of each location on the ceiling surface and floor surface to be inspected in the piping section 3, and a lower camera 44 that recognizes the lower part of the aircraft 4. The aircraft 4 is, for example, a small unmanned aircraft such as a drone. As shown in FIG. 1, the aircraft 4 flies autonomously along a flight path R.

[0045] The flying object 4 starts autonomous flight from a state where it is placed on a mark 25 installed near the manhole opening 21. The flying object 4 takes off from the mark 25, for example, when the power is switched on by an operation of the user of the flying object 4. The flying object 4 has a maximum diameter in a plan view during flight that is shorter than the distance between the front part 233c of the step 23 of the tread 23 and the opposing inner wall surface 22.

[0046] When the flying object 4 passes through the manhole neck 2, the separation distance between the flying object 4 and the inner wall surface 22 of the manhole neck 2 and the step cover 1 is about several centimeters to several tens of centimeters. Therefore, the flying object 4 needs to fly accurately on a flight path R along a position near the center of the manhole neck 2, for example, so as not to come into contact with the inner wall surface 22 of the manhole neck 2. In this embodiment, an example is given in which it is difficult to receive radio waves emitted from a satellite positioning system such as GPS inside the manhole neck 2 and the piping section 3, which are underground. Therefore, the flying object 4 performs autonomous flight at least in the manhole neck 2 and the piping section 3 without using a satellite positioning system such as GPS.

[0047] In the present embodiment, the flying object 4 flies to inspect the inside of the piping 3 in which the communication cable is laid, but the present invention is not limited to this. The flying object 4 may fly to inspect the inside of water supply and sewerage pipes, the inside of structures such as boilers and chimneys, etc.

[0048] The mark 25 is, for example, a predetermined pattern or symbol printed on a sheet. The mark 25 indicates the takeoff and landing point of the aircraft 4. In FIG. 1, the mark 25 is a symbol having an "H" shape in a plan view. The mark 25 is not limited to the above configuration, and any pattern or symbol can be used as the mark 25. The material of the sheet on which the mark 25 is attached is not limited, and may be, for example, rubber, plastic, vinyl, or metal. Since the mark 25 is installed outdoors, the sheet has a weight and frictional force with the ground that does not move even when blown by the wind. The sheet may be fixed to the ground by, for example, a stake. Instead of being attached to the sheet, the mark 25 may be directly drawn on the ground by, for example, paint.

[0049] A method for inspecting a piping section 3 by passing through a manhole neck 2 having a step cover 1 installed on an elevation section 24 of an aircraft 4 will be described below.

[0050] The flying object 4 is initially placed on the mark 25, and when it takes off from the mark 25, it starts to rise to approximately directly above the mark 25. The flying object 4 stops rising when it reaches a predetermined height. When the flying object 4 stops rising, it moves horizontally to the ground while maintaining the predetermined height, and flies to a position directly above the manhole opening 21.

[0051] Any method may be used to detect that the flying object 4 has reached a predetermined height. For example, the flying object 4 may be equipped with an altimeter. Alternatively, for example, the flying object 4 may measure the distance from its own position to the position of the mark 25 using a distance measuring sensor. Alternatively, the flying object 4 may measure the altitude using a satellite positioning system such as a GPS. Alternatively, the flying object 4 may capture an image of the mark 25 or the like using the lower camera 44 and estimate the altitude by image analysis.

[0052] Any method may be used for the flying object 4 to move to a position directly above the center of the manhole opening 21. For example, the flying object 4 may measure its own position using a satellite positioning system such as a GPS, and move to a position directly above the manhole opening 21 that has been measured in advance. Alternatively, for example, the flying object 4 may capture an image in the direction of the ground with the lower camera 44, and identify and move to a position directly above the manhole opening 21 through image analysis.

[0053] When the flying body 4 moves to a position directly above the manhole opening 21, it begins to descend in a direction perpendicular to the ground. The flying body 4 enters the manhole neck 2 from the manhole opening 21. The flying body 4 passes through the manhole neck 2 without directly contacting the lifting section 24, and reaches the piping section 3. Even if the flying body 4 comes into contact with the step cover 1, there is no direct contact between the flying body 4 and the lifting section 24, and the flying body 4 can continue flying without being affected in its flight state.

[0054] The flying object 4 stops descending when it reaches the piping section 3. The flying object 4 moves through the piping section 3 while capturing images of the inside of the piping section 3 with the inspection camera 43. The flying object 4 outputs captured and recorded images of the ceiling and floor surfaces of the piping section 3 to an external device, for example, through a user's operation. The captured videos and images are shared in real time, and the inside of the piping section 3 can be inspected based on the captured videos and images.

[0055] Any method may be used for the flying object 4 to reach the piping section 3. For example, the flying object 4 may detect that it has reached the piping section 3 by measuring the distance to the bottom surface of the piping section 3 with a sensor. Also, for example, the flying object 4 may capture an image of the downward direction of the flying object 4 with the lower camera 44 and detect that it has reached the piping section 3 by image analysis.

[0056] When the aircraft 4 completes the inspection flight of the piping section 3, it moves to a position directly below the center of the manhole neck 2. The method by which the aircraft 4 moves to a position directly below the center of the manhole neck 2 is to detect the position marker 16 at the bottom end of the step cover with the upper camera 41, identify the opening position of the manhole neck 2, and move to a position directly below it. The aircraft 4 may also capture an image in the upward direction with the upper camera 41, identify the position directly below the center of the manhole neck 2 through image analysis, and move to that position.

[0057] When the flying object 4 moves to a position directly below the center of the manhole neck 2, it re-enters the manhole neck 2 and begins to rise toward the ground. The flying object 4 passes through the manhole neck 2 without directly coming into contact with the lifting section 24, just as when it accessed the piping section 3, reaches the manhole opening 21, and emerges on the ground. Even if the flying object 4 comes into contact with the step cover 1, there is no direct contact between the flying object 4 and the lifting section 24, and the flying object 4 can continue flying without being affected in its flight state.

[0058] The flying object 4 passes through the manhole neck 2 and emerges on the ground. The flying object 4 continues to rise to a predetermined height directly above the manhole neck 2. When the flying object 4 reaches the predetermined height, it stops rising and moves horizontally to the ground while maintaining the predetermined height, flying to a position directly above the mark 25.

[0059] A height marker 17 is used as a method for detecting that the flying object 4 has reached a predetermined height within the manhole neck 2. The height marker 17 is not an essential component. For example, the flying object 4 may be equipped with an altimeter. Alternatively, for example, the flying object 4 may measure the distance from its own position to the position of the manhole opening 21 using a distance measuring sensor. Alternatively, the flying object 4 may measure the altitude using a satellite positioning system such as a GPS. Alternatively, the flying object 4 may capture an image of the manhole opening 21 using the lower camera 44 and estimate the altitude by image analysis.

[0060] Any method may be used for the flying object 4 to move to a position directly above the mark 25. For example, the flying object 4 may measure its own position using a satellite positioning system such as a GPS, and move to a position directly above the mark 25 that has been measured in advance. Alternatively, for example, the flying object 4 may capture an image in the direction of the ground with the lower camera 44, and identify and move to a position directly above the mark 25 through image analysis.

[0061] When the flying object 4 flies to a position directly above the mark 25, it starts descending toward the mark 25. When the flying object 4 lands on the mark 25, it ends its autonomous flight. Any method may be used to recognize that the flying object 4 has landed on the mark 25. For example, the flying object 4 may be equipped with an altimeter. Alternatively, for example, the flying object 4 may recognize that it has landed on the mark 25 by measuring the distance from its own position to the ground using a distance measuring sensor. Alternatively, the flying object 4 may be equipped with, for example, a speedometer, and may recognize that it has landed on the mark 25 based on the speed becoming 0.

[0062] In this embodiment, the flying object 4 moves vertically and parallel, but is not limited to this. For example, the flying object 4 may rise diagonally upward from the position of the mark 25 and move in a straight flight path to a position directly above the center of the manhole opening 21. Also, for example, the flying object 4 may descend diagonally downward from a position directly above the center of the manhole opening 21 and move in a straight flight path to a position above the mark 25.

[0063] With the step cover according to the first embodiment, the upper guide portion 14 and the lower guide portion 15 are formed with an upward and downward inclination, so that when the flying object 4 comes into contact with the step cover 1, it is possible to prevent the flying object 4 from getting caught on the step cover 1. With the step cover according to the first embodiment, the friction coefficient of the surfaces of the upper guide portion 14 and the lower guide portion 15 is small, so that when the flying object 4 comes into contact with the step cover 1, it is possible to easily separate the flying object 4 from the step cover 1 without getting caught on the step cover 1. Therefore, it is possible to prevent the flying object 4 from becoming uncontrollable, falling, being damaged, etc. due to contact with the lifting portion 24.

[0064] The step cover 1 is provided so as to cover the treads 233 of each step 23 at the central portion 241 of the manhole neck 2 in a plan view, thereby preventing the flying object 4 flying over the manhole neck 2 from coming into contact with the steps 23 and being impeded in flight. This makes it possible to prevent the flying object 4 from getting caught in the lifting section 24 when flying over the narrow manhole neck 2, or from becoming uncontrollable, falling, being damaged, etc., due to contact, and enables the flying object 4 to pass through the narrow area safely without affecting its flight posture due to contact, etc.

[0065] The step cover 1 has a plurality of elastic linear covers 111 and hook-shaped upper and lower attachment parts 12 and 13 at the upper and lower ends of the cover part 11, so that the step cover 1 can be firmly fixed to the lifting part 24 so as to cover the central part 241 in a plan view. Therefore, the step cover 1 can be prevented from being easily rolled up by external forces such as wind generated by the propeller of the flying object 4.

[0066] The step cover 1 has the position marker 16, which makes it possible for the flying object 4 to easily recognize the opening position of the manhole neck 2 when entering the manhole neck 2. This makes it possible to prevent the flying object 4 from coming into contact with the step cover 1, the inner wall surface 22, etc. when entering the manhole neck 2.

[0067] The step cover 1 has height markers 17, which allows the flying object 4 to easily recognize the height of the flying object 4 within the manhole neck 2 when it flies within the manhole neck 2. Therefore, when the flying object 4 rises near the ground when it leaves the manhole neck 2 to leave the ground, the upper camera 41 and the side camera 42 are activated to detect the shape of the manhole opening 21 and the height of the flying object 4 at the time of image capture, making it possible for the flying object 4 to easily control its flight when leaving the ground without coming into contact with the step cover 1 or the inner wall surface 22.

[0068] <Second embodiment> Hereinafter, a second embodiment of the step cover according to the present invention will be described with reference to the drawings. FIG. 4 is a schematic diagram showing the mounting state of the step cover in this embodiment. This embodiment differs from the above-described first embodiment in terms of the cover portion 11. The other corresponding components are given the same reference numerals and the description thereof will be omitted.

[0069] The cover portion 11 in this embodiment has a rectangular cover 114. The rectangular cover 114 is formed of a sheet-like member having a thickness of about several mm and a rectangular shape when viewed from the front. The upper attachment portion 12 and the upper guide portion 14 are connected to and integrated with an upper end portion 114a of the rectangular cover 114. The lower attachment portion 13 and the lower guide portion 15 are connected to and integrated with a lower end portion 114b of the rectangular cover 114.

[0070] The width of the rectangular cover 114 is longer than the width of the step bar 233. Therefore, the cover portion 11 is a sheet-like cover provided so as to completely cover the step bar 233 of each step 23 with respect to the central portion 241 in a plan view. The rectangular cover 114 is not limited to the configuration of this embodiment as long as it can be formed to cover the lifting portion 24. For example, the rectangular cover 114 may be formed of a soft plate-like member having a thickness of about several centimeters.

[0071] According to the step cover 1 of the second embodiment, the cover portion 11 is formed so as to completely cover the tread 233 of each step 23 with respect to the central portion 241 in plan view. Therefore, the step cover 1 of this embodiment can more reliably prevent the flying object 4 from directly contacting the lifting portion 24.

[0072] <Third embodiment> Hereinafter, a third embodiment of the step cover according to the present invention will be described with reference to the drawings. FIG. 5 is a schematic diagram showing an attachment state of the step cover in this embodiment. This embodiment differs from the first and second embodiments described above in terms of the cover portion 11, the lower mounting portion 13 and the lower guide portion 15. The other corresponding components are given the same reference numerals and their description will be omitted.

[0073] The step cover 1 in this embodiment includes a cover portion 11, an upper mounting portion 12, an upper guide portion 14, a position marker 16, a height marker 17, and a weight portion 18. The configuration of the step cover 1 other than the weight portion 18 is the same as that of the first embodiment.

[0074] The weight portion 18 is formed of a weight made of a metal material, is attached to the lower cover end portion 113 of the cover portion 11, and has a predetermined weight that applies downward tension to the cover portion 11, thereby putting the cover portion 11 into a tensed state.

[0075] According to the step cover 1 of the third embodiment, the cover part 11 is always in a downward tension state, so even if it is hit by wind generated by the propeller of the flying object 4, the cover part 11 will not be rolled up, and it is possible to maintain the covering state of the lifting part 24. Even if the flying object 4 comes into contact with the cover part 11, the cover part 11 will repel the force of the contact and return the flying object 4 to the flying state, and the cover part 11 can easily return to the normal position.

[0076] <Fourth embodiment> Hereinafter, a fourth embodiment of the step cover according to the present invention will be described with reference to the drawings. FIG. 6 is a schematic diagram showing the mounting state of the step cover in this embodiment. This embodiment differs from the above-described second embodiment in terms of the cover portion 11. The other corresponding components are given the same reference numerals and the description thereof will be omitted.

[0077] The cover portion 11 further includes a cover upper end extension portion 115, a cover lower end extension portion 116, and an extended rectangular cover 117 in addition to the configuration of the second embodiment.

[0078] The cover upper end extension portion 115 extends from both ends 114c, 114d of the upper end portion 114a of the rectangular cover 114 toward the inner wall surface 22 along the first protruding portion 231 and the second protruding portion 232. The cover upper end extension portion formed on the first protruding portion 231 side is designated as 115a, and the cover upper end extension portion formed on the second protruding portion 232 side is designated as 115b.

[0079] The cover lower end extension portion 116 extends from both ends 114e, 114f of the lower end portion 114b of the rectangular cover 114 along the first protruding portion 231 and the second protruding portion 232 toward the inner wall surface 22. The cover lower end extension portion formed on the first protruding portion 231 side is designated as 116a, and the cover lower end extension portion formed on the second protruding portion 232 side is designated as 116b.

[0080] The lengths in the extension direction of cover upper end extension portion 115a and cover lower end extension portion 116a formed on the first protruding portion 231 side are approximately the same. The lengths in the extension direction of cover upper end extension portion 115b and cover lower end extension portion 116b formed on the second protruding portion 232 side are approximately the same. Cover upper end extension portion 115 and cover lower end extension portion 116 are formed integrally with and continuous to upper end portion 114a and lower end portion 114b, respectively.

[0081] The extended rectangular cover 117 is installed between the cover upper end extension portion 115 and the cover lower end extension portion 116. The extended rectangular cover 117 is formed of the same shape and material as the rectangular cover 114. The extended rectangular cover 117a formed on the first protruding portion 231 side is arranged at equal intervals from the ends of the cover upper end extension portion 115a and the cover lower end extension portion 116a along the extension direction of the first protruding portion 231. The extended rectangular cover 117b formed on the second protruding portion 232 side is arranged at equal intervals from the ends of the cover upper end extension portion 115b and the cover lower end extension portion 116b along the extension direction of the second protruding portion 232. Therefore, the step cover 1 is a sheet-like cover formed in a U-shape when viewed from above, which is arranged to cover both ends of the tread 233 of each step 23 and the corner portions 234a, 234b consisting of protruding ends 231a and 232a connected to both ends of the tread 233 of the first protruding portion 231 and the second protruding portion 232, relative to the central portion 241 when viewed from above.

[0082] With the step cover of the fourth embodiment, the step cover 1 is able to protect the flying body 4 and the lifting section 24 when the step cover 1 comes into contact with the flying body 4, and allow the flying body 4 to continue flying, even in a manhole neck 2 where a wide gap is formed between the lifting section 24 and the inner wall surface 22 that face each other in the extension direction of the first protrusion 231 and the second protrusion 232.

[0083] The step cover 1 is capable of protecting the flying object 4 and the lifting section 24 when the flying object 4 comes into contact with the step cover 1, even if the flying object 4 is small.

[0084] Although the embodiment of the step cover according to the present invention has been described above, the specific configuration is not limited to the above embodiment and can be appropriately changed within the scope of the present invention. For example, in the first embodiment, the step cover 1 is attached to the lifting section 24 by engaging the upper mounting section 12 and the lower mounting section 13 and expanding and contracting the cover section 11, but the configuration is not limited to the above as long as the upper mounting section 12 and the lower mounting section 13 can be engaged in a desired configuration. For example, the upper mounting section 12 and the lower mounting section 13 may be attached to the uppermost step 23a and the lowermost step 23b by attaching a string-like member whose length can be adjusted to each of them and hanging the upper mounting section 12 and the lower mounting section 13 from the ground.

[0085] In the above embodiment, an example was shown in which the upper guide portion 14 and the lower guide portion 15 were provided, but the upper guide portion 14 and the lower guide portion 15 are not essential components. In order to guide the autonomous flight of the flying object 4 so that the flying object 4 can autonomously fly in and out of the inside of the manhole neck 2 without coming into contact with the lifting / lowering portion 24, it is sufficient that the flying object 4 is provided with a cover portion 11 that covers the lifting / lowering portion 24 and is engaged by the upper mounting portion 12, as shown in FIG.

[0086] In the above embodiment, the upper guide portion 14 and the lower guide portion 15 are connected to the inner wall surface 22 by the double-sided tape portions 14a and 15a, respectively, but the connection form between the upper guide portion 14 and the lower guide portion 15 and the inner wall surface 22 is not limited to this example. For example, the upper guide portion 14 and the lower guide portion 15 may be connected to the inner wall surface 22 by providing an engagement portion between the upper guide portion 14 and the lower guide portion 15 and the inner wall surface 22.

[0087] In the above-described third embodiment, the weight portion 18 is provided in the configuration of the first embodiment, but the weight portion 18 may be provided in the configuration of the second embodiment. In the above-described fourth embodiment, the extension portions are provided in the configuration of the second embodiment, but the extension portions may be provided in the configuration of the first embodiment.

[0088] In the above-described fourth embodiment, the step cover 1 is arranged to cover a portion of the extension direction of the first protrusion 231 and the second protrusion 232, but it may be formed to completely cover the first protrusion 231 and the second protrusion 232 up to the connection point with the inner wall surface 22. [Explanation of symbols]

[0089] 1···Step cover, 2···Structure (manhole neck), 3···Pipe section, 4···Air vehicle, 11···Cover section, 12···Upper mounting section, 13···Lower mounting section, 14···Upper guide section, 15···Lower guide section, 16···Position marker, 17···Height marker, 22···Inner wall surface, 23···Step, 23a···Uppermost step (upper step), 23b···Lowestest step (lower step), 24···Lifting section, 111···Linear cover, 112···Upper end of cover, 113···Lower end of cover, 233···Step bar, 234a, 234b···Corner section

Claims

1. A step cover provided on a lifting section having a plurality of steps protruding from an inner wall surface of a structure having a space in which an aircraft flies autonomously, A cover section that is installed between the uppermost step and the lowermost step of the plurality of steps and covers the lift section; An upper mounting portion provided at an upper end portion of the cover portion and attached to the upper step; Equipped with The upper mounting portion is configured to be installed on the lifting portion from above. Step cover.

2. The upper mounting portion has a hook shape that engages with the upper step from above. The step cover according to claim 1 .

3. A lower mounting portion is provided at a lower end of the cover portion and is attached to the lower step. The step cover according to claim 1 or 2.

4. The cover portion or the lower mounting portion is provided with an expandable portion. The step cover according to claim 3 .

5. an upper guide portion inclined upward from an upper end of the cover portion toward the inner wall surface; A step cover according to any one of claims 1 to 4.

6. A lower guide portion is provided which is inclined downward from a lower end of the cover portion toward the inner wall surface. A step cover according to any one of claims 1 to 5.

7. The cover portion is made of a soft planar member. A step cover according to any one of claims 1 to 6.

8. The cover portion is configured by a plurality of linear members extending in a vertical direction being aligned and fixed to an upper end portion of the cover portion. A step cover according to any one of claims 1 to 7.

9. The lateral length of the cover portion is longer than the width of the step bar of the step. A step cover according to any one of claims 1 to 8.

10. The cover portion covers corner portions at both ends of the tread of the step in the width direction. A step cover according to any one of claims 1 to 9.

11. The cover portion is provided at a lower end thereof with a position marker that can be detected by the flying object. A step cover according to any one of claims 1 to 10.

12. The cover portion is provided with a height marker that indicates a height position and is detectable by the flying object. A step cover according to any one of claims 1 to 11.

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