JP7442174B2 - Multicopter for structural inspection - Google Patents

Description

The present invention relates to a multicopter for inspecting structures suitable for inspecting concrete and steel frames of bridges and elevated structures, inspecting inner walls of tunnels, and the like.

Many social infrastructure structures were constructed in Japan during the period of high economic growth, but 50 years have passed since then, and the deterioration of these structures has become noticeable. Therefore, these must be inspected to detect deterioration, but inspection points are often located at high places, and there are said to be hundreds of thousands of inspection points nationwide, making it safe and inexpensive. Moreover, a simple testing method is required.

In response to such demands, Patent Document 1 proposes a device for inspecting elevated structures by raising and lowering the inspection device using a lifting device installed at the top of a vehicle.

Further, Patent Document 2 proposes a method of moving an inspection device restrained by a wire on the underside of an elevated structure by adjusting the length of the wire. These are patents for devices and methods for bringing an inspection device close to the underside of an elevated structure, but both require large devices and are not cheap and simple methods. On the other hand, with the recent development of multicopters, apparatuses and methods for inspecting structures such as elevated structures and tunnel interiors using multicopters have been proposed.

In Patent Document 3, the multicopter is equipped with legs on the top, and by making the lifting force larger than its own weight, it sticks to the lower surface of the structure and maintains a constant relative position between the inspection device installed on the multicopter and the structure. I can do it. However, with this method, when moving to the next inspection point on the structure, the structure must be moved away and then reattached, and if the next inspection point is close to the current location, energy and It will be a waste of time. This document also proposes that power be supplied from the ground via a cable. By supplying power from the ground, it is possible to fly semi-permanently, but in strong winds the resistance of the wind to the cables makes it difficult to control the aircraft's position.

Patent Document 4 proposes using wheels instead of legs. According to this method, the vicinity of the grounding point can be inspected while being adsorbed to the lower surface of the structure. However, this method requires a lifting force greater than its own weight to be absorbed, which consumes more energy than during flight. Furthermore, because the distance between the wheels and the center of gravity is long, a large moment is generated when the vehicle adsorbs to an inclined wall surface, and a large amount of energy is consumed to counteract this moment.

Patent Document 5 proposes a device that has wheels equipped with magnets to attract the wheels to a wall surface and reduce energy consumption during inspection. However, this method is not suitable for inspecting structures made of concrete because the objects that can be absorbed are limited to steel frames.

In Patent Document 6, a ducted fan is equipped on the side of a multicopter, and the multicopter is attracted to a vertical wall surface to stabilize its position in the front, rear, left, and right directions. However, with this method, it is not possible to inspect a horizontal wall surface while moving.

Japanese Patent Application Publication No. 3-260206 JP2017-95959A Japanese Patent Application Publication No. 2015-223995 Japanese Patent Application Publication No. 2016-211878 JP2019-84868A Japanese Patent Application Publication No. 2018-165131

As mentioned above, there are various problems when using a multicopter for inspecting structures. The present invention attempts to solve such problems.
An object of the present invention is to provide a multicopter for inspecting structures that can reduce energy consumption when inspecting walls of structures.

Another object of the present invention is to provide a structure inspection multi-copter that can continuously move from a horizontal wall surface to an inclined wall surface when inspecting a structure with an area where the wall surface is inclined. Our goal is to provide the following.

Another object of the present invention is to provide a multi-copter for inspecting structures that is capable of continuously moving over an inclined wall surface when inspecting a structure having an area where the wall surface is typically inclined. Our goal is to provide the following.

In order to solve the above problems, a multicopter for structure inspection according to the present invention is a multicopter for structure inspection in which the upper side sticks to at least the lower surface of the wall surface of the structure to be inspected by the thrust of the rotor during inspection, A holding member is provided for holding the distance between the rotating surface of the rotor and the wall surface of the structure to be inspected close to 50% or less of the radius of the rotor during inspection. Thereby, energy consumption can be reduced by about 10% or more. The plane of rotation formed by the rotor typically refers to the plane drawn by the tips of the rotor blades.

In the structure inspection multicopter according to the present invention, the distance between the rotating surface of the rotor and the wall surface of the structure to be inspected is 20% or less of the radius of the rotor during the inspection. It may also be a device for holding the device close to the device. By setting it to 20% or less, energy consumption can be sharply reduced.

In the structure inspection multicopter according to the present invention, the holding member may include wheels for traveling on a wall surface of the structure to be inspected. This allows the inspection to be performed while continuously moving on the wall surface.

The structure inspection multicopter according to the present invention is equipped with a gyro sensor that detects the angle of the body of the structure inspection multicopter, and when stuck to the wall surface of the structure to be inspected, the wheels are moved to the wall surface. according to the angle of the aircraft body detected by the gyro sensor so that the frictional force between the wall surface and the wheels generated by pressing against the wall surface generates a thrust force greater than or equal to a magnitude that fixes the aircraft body in a fixed position on the wall surface. The rotation speed of the rotor may be adjusted by adjusting the rotation speed of the rotor. As a result, typically when inspecting a structure that has an area where the wall surface is inclined, the inspection can be performed while continuously moving on the inclined wall surface.

The structure inspection multicopter according to the present invention may include four rotors, and may further include a guard containing the four rotors, and further include a plurality of contact sensors arranged along the outer periphery of the guard. Further, when any one of the plurality of contact sensors detects contact, the four rotors are configured to overturn the aircraft using the contact point of the contact sensor that detected the contact as a fulcrum. Rotation may also be controlled. As a result, when inspecting a structure with an area where the wall surface is inclined, the inspection can be performed while continuously moving from a horizontal wall surface to an inclined wall surface.

The structure inspection multicopter according to the present invention may include four concentric wheels.

The structure inspection multicopter according to the present invention includes a rotation holding member that rotatably holds each of the wheels around the vertical axis of the aircraft body, and a rotation drive unit that rotationally drives each of the wheels around the vertical axis of the aircraft body, When the structure inspection multicopter is rotated around the vertical axis of the vehicle, the rotation drive unit may be controlled so that each of the wheels runs along a concentric circle. A gimbal can typically be used as the rotation holding member. A servo motor can be used as the rotation drive unit. Thereby, for example, it is possible to move from the reference coordinates to a desired direction on the wall surface.

The multicopter for structure inspection according to the present invention includes a rotary encoder that measures the rotation of the wheels, measures the distance traveled by the aircraft based on the measurement results by the rotary encoder, and calculates the inspection position based on the measurement results. You may. Thereby, it is possible to match the inspection results and inspection positions on the wall surface.

The multicopter for inspecting structures according to the present invention may be equipped with an inspection device such as a hammering inspection device or a camera for inspecting the wall surface of the structure.

The structure inspection multicopter according to the present invention is a structure inspection multicopter whose upper side sticks to the wall surface of the structure to be inspected due to the thrust of the rotor during inspection, and which travels on the wall surface of the structure to be inspected. and a gyro sensor that detects the angle of the structure inspection multicopter. The rotor is rotated in accordance with the angle of the aircraft detected by the gyro sensor so that the friction force between the wall and the wheels generates a thrust greater than or equal to the magnitude that fixes the aircraft in a fixed position on the wall. Adjust the number. As a result, typically when inspecting a structure that has an area where the wall surface is inclined, the inspection can be performed while continuously moving on the inclined wall surface.

The structure inspection multicopter according to the present invention is a structure inspection multicopter whose upper side sticks to the wall surface of the structure to be inspected due to the thrust of the rotor during inspection, and is equipped with a plurality of the rotors and A plurality of wheels for running on a wall surface of a structure, a guard containing the plurality of rotors, and a plurality of contact sensors arranged along the outer periphery of the guard, the plurality of contact sensors When any of them detects contact, the rotation of the plurality of rotors is controlled so as to roll the aircraft over the point of contact by the contact sensor that detected the contact.

The multi-copter for structure inspection according to the present invention is a multi-copter for structure inspection whose upper side sticks to the wall surface of the structure to be inspected by the thrust of the rotor during inspection. a rotation holding member that rotatably holds each of the wheels around the vertical axis of the aircraft body; a first rotation drive unit that rotationally drives each of the wheels around the vertical axis of the aircraft body; a second rotary drive unit that rotates with respect to the axis of the wheel; and a second rotary drive unit that rotates the multicopter for structure inspection around the vertical axis of the vehicle so that each of the wheels runs along a concentric circle. and a control section that controls one rotational drive section.

Thereby, for example, it is possible to move from the reference coordinates to a desired direction on the wall surface.

According to the present invention, it is possible to reduce energy consumption when inspecting a wall surface of a structure at a high place, for example. According to the present invention, when inspecting a structure with an area where the wall surface is inclined, the inspection can be performed while continuously moving from a horizontal wall surface to an inclined wall surface. According to the present invention, when inspecting a structure having an area where the wall surface is typically inclined, the inspection can be performed while continuously moving on the inclined wall surface.

FIG. 1 is a top view of a multicopter for inspecting structures according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view (including a partial sectional view) of a multicopter for inspecting structures according to an embodiment of the present invention. FIG. 1 is a block diagram showing the configuration of a multicopter for inspecting structures according to an embodiment of the present invention. This is a graph of the chord length distribution of the rotor used in calculations. It is a graph of the installation angle distribution of the rotor used for calculation. FIG. 3 is a diagram showing the velocity field around the rotor. This is the velocity field around the rotor near the wall. FIG. 3 is a diagram showing blade elements of a rotating rotor. FIG. 3 is a diagram showing the blade elements of a rotating rotor when close to a wall surface. It is a graph showing the number of rotations of the rotor required when the thrust is constant. This is a graph showing the rotor power required when the thrust is constant. FIG. 2 is a front view showing the movement of the structure inspection multicopter according to an embodiment of the present invention when it adsorbs to a horizontal wall surface. FIG. 2 is a front view showing the movement of the structure inspection multicopter according to an embodiment of the present invention when it adsorbs to a diagonal wall surface. FIG. 2 is a front view showing the movement of the structure inspection multicopter according to an embodiment of the present invention when it adsorbs to a vertical wall surface. 1 is a flowchart showing an operation when a multicopter for structure inspection according to an embodiment of the present invention adsorbs to a wall surface. 2 is a flowchart showing the operation of the structure inspection multicopter according to an embodiment of the present invention when it leaves a wall surface. It is a flowchart which shows the operation|movement when the multicopter for structure inspection based on one Embodiment of this invention changes direction. FIG. 2 is a top view showing the orientation of the wheels of the structure inspection multicopter according to an embodiment of the present invention when moving in the front-rear direction. FIG. 2 is a top view showing the orientation of the wheels of the multicopter for structure inspection according to an embodiment of the present invention when changing direction. 2 is a flowchart showing the operation of the structure inspection multicopter according to an embodiment of the present invention when it moves in the front-rear direction. 1 is a flowchart showing an operation when a multicopter for structure inspection according to an embodiment of the present invention moves in the left-right direction. FIG. 2 is a top view showing the orientation of the wheels of the structure inspection multicopter according to an embodiment of the present invention when moving in the left-right direction.

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments in any way.

FIG. 1 is a top view of a multicopter for inspecting structures according to an embodiment of the present invention. FIG. 2 is a front view of a multicopter for inspecting structures according to an embodiment. In FIG. 2, a portion corresponding to the cross-sectional line indicated by the thin and wavy line in FIG. 1 is shown in cross section. FIG. 3 is a block diagram showing the configuration of a multicopter for inspecting structures according to an embodiment.

The structure inspection multicopter 100 has a roughly disk-like shape. A main body 8 is disposed at the center of the multicopter 100 for inspecting structures.

Inside the main body 8, a CPU 71, a receiver 72, a gyro sensor 73, an acceleration sensor 74, a battery 75, and ESCs (Electric Speed Controllers) 76 to 78 are provided.

When the aircraft is stuck to the wall of the structure to be inspected, the CPU 71 generates a thrust force such that the frictional force between the wall and the wheels 4 generated by pressing the wheels 4 against the wall is greater than the magnitude that fixes the aircraft in a fixed position on the wall. The rotational speed of the rotor 1 is adjusted according to the angle of the aircraft body detected by the gyro sensor 73 so as to generate the rotation speed.

Four levitation motors 2 and a rotor 1 rotated by the motors 2 are radially coupled to the main body 8 via a rotor support 3 . Further, four gimbals 6 having variable swing angles are concentrically and radially connected to the main body 8 via a wheel strut 9 by a servo motor 81.

A moving motor 5 with a reduction gear is fixed to the gimbal 6, and this moving motor 5 with a reduction gear drives the wheels 4 for traveling on the wall surface of the structure to be inspected. The rotary encoder 82 measures the rotation of the wheel 4. The CPU 71 measures the moving distance of the aircraft based on the measurement results obtained by the rotary encoder, and calculates the inspection position based on the measurement results.

An inspection device 7 for inspecting the wall surface of the structure is installed in the middle of the wheel strut 9, and a guard strut 10 extending from the wheel strut 9 ensures that the guard 11 containing the four rotors 1 is aligned with the rotating surface of the rotor 1. held at a height. A plurality of contact sensors 12 are arranged along the outer periphery of the guard 11. When any one of the plurality of contact sensors 12 detects contact, the CPU 71 controls the rotation of the four rotors 1 so as to overturn the aircraft using the contact point of the contact sensor 12 that detected the contact as a fulcrum.

The inspection device 7 in the structure inspection multicopter 100 according to the present embodiment includes a hammering inspection device 83, a camera 84, and an SSD (Solid State Drive) 85 as a storage means for storing these inspection results.

The structure inspection multicopter 100 floats due to the upward thrust generated by the rotor 1. During inspection, the multicopter 100 for inspecting structures sticks its upper side to the wall surface of the structure to be inspected due to the thrust of the rotor 1.

The mode switch 201 of the control device 200 instructs the movement of the structure inspection multicopter 100. For example, the mode switch 201 can be set to suction mode. The command value from the control device 200 is sent to the structure inspection multicopter 100 by radio waves, and is received by the receiver 72 built into the main body 8 of the structure inspection multicopter 100. The CPU 71 processes the command value from the pilot device 200, the signal from the gyro sensor 73, and the signal from the acceleration sensor 74, and calculates the control amount of the motor 2 for levitation. Based on the calculated control amount, the ESC 75 controls the current to the levitation motor 2, and the levitation motor 2 is driven by this current to rotate the rotor 1.

The inspector maneuvers the structure inspection multicopter 100 to approach the wall surface of the structure to be inspected.

Figures 4 and 5 show the chord length distribution and attachment angle distribution of a rotor designed to maximize static thrust, respectively. The shape of the rotor 1 is given by FIGS. 4 and 5, and the rotor 1 generates a thrust of 269.5 gf when the rotation speed is 9000 rpm, and the required power is 19.74 W. Therefore, the total thrust of the four rotors 1 is 1078 gf, and the required power is 78.96 W.

During inspection, the multicopter 100 sticks to the wall surface of the structure to be inspected by the thrust of the rotor 1 via the outer peripheral end of the wheel 4 (near the top end of the wheel 4) located on the upper side thereof. In the structure inspection multicopter 100 according to the present embodiment, the wheels 4 serve as holding members for keeping the distance between the rotating surface of the rotor 1 and the wall surface of the structure to be inspected close to each other during inspection. also works. Due to the intervention of the wheel 4, which functions as a holding member, the distance between the rotating surface of the rotor 1 and the wall surface of the structure to be inspected during inspection is 50% or less, more preferably 20% or less, of the radius of the rotor. , more preferably held closer together by less than 10%. That is, in the multicopter 100 for structure inspection according to the present embodiment, wheels 4 driven by a movement motor 5 with a reduction gear are provided at the four corners above the rotating surface of the rotor 1, and the thrust of the rotor 1 is used to move the wheels 4 onto the wall surface. The distance between the rotor 1 and the wall surface during adsorption is set to be 50% or less of the diameter of the rotor 1, more preferably 20% or less, and still more preferably less than 10%.

As described above, when this rotor 1 is rotated at 9000 revolutions per minute, the thrust is 2.641N and the required power is 19.743W. FIG. 6 shows the velocity vector around the rotor 1 at this time. When this rotor 1 is rotated at a distance of 2 cm from the wall, the flow on the front surface of the rotor 1 flows from the outer periphery as shown in FIG. 7, and the velocity component in the direction of the rotation axis becomes small. The required power of the rotor 1 is the sum of the power due to shape resistance and the power due to induced energy loss. Of these, the induced energy loss is proportional to the product of the velocity component in the direction of the rotational axis and the circulation of the rotor blades, and assuming that this circulation is constant regardless of the distance to the wall, the induced energy loss is becomes smaller. Further, the thrust generated by the rotor 1 is proportional to the lift generated by the rotor blades, which in turn is proportional to the angle of attack of the rotor blades. This angle of attack is the value obtained by subtracting the inflow angle from the blade angle, but when the rotor 1 is rotated near a wall, the axial velocity component becomes smaller, so the inflow angle becomes smaller. Therefore, the angle of attack of the rotor blades increases, and the thrust of the rotor 1 increases. Therefore, when the rotor 1 rotates near the wall surface, the thrust generated increases at a constant rotation speed and the required power decreases.

This induced energy loss is given by:

FIG. 8 shows the blade elements of the rotating rotor 1. The rotor 1 rotates at a rotational speed Ω, and when the blade element radius is r, the rotational direction speed of the blade element is rΩ. Further, let v be the speed in the rotational axis direction induced by the rotor. As a result, the inflow velocity V is given by the following equation.
V=√{(rΩ) ² +v ² }
Also, the inflow angle φ is φ=arctan (v/rΩ)
is given by If the installation angle of the blade element is θ, the angle of attack α is α=θ−φ
is given by Lift force L is generated at right angles to the inflow velocity V,
L=(ρV ² aαS)/2
is given by Here, ρ is the air density, a is the lift slope, and S is the area of the wing element. This lift force L is divided into an axial direction and a rotational direction, each of which is a thrust force T and a drag force D. The product of this drag force D and the rotational speed rΩ is the induced energy loss.

When the flow is close to the wall surface, the flow is obstructed by the wall surface, and the induced velocity v in the axial direction decreases to v' as shown in FIG. As a result, the inflow angle decreases to φ'. Along with this, the backward inclination angle of the lift force L' decreases, and the new thrust force T' becomes larger than the thrust force T. Further, the new drag force D' becomes smaller than the drag force D. Therefore, when near the wall, the induced energy loss is small and the required power is reduced.

If this thrust is constant, the required rotational speed decreases as the vehicle approaches the wall. FIG. 10 shows the required rotational speed of the rotor 1 when the distance between the rotor 1 and the wall surface is changed under the condition that this constant thrust is generated. Also, if the thrust is constant, the closer you get to the wall, the lower the power required. FIG. 11 shows the power required when the distance between the rotor 1 and the wall surface is changed under the condition that this constant thrust is generated.

FIG. 12 shows how this multicopter 100 for inspecting structures is adsorbed to the lower surface of an upper horizontal wall surface. The investigator operates the structure inspection multicopter 100 to bring the structure inspection multicopter 100 close to the location to be inspected. As the thrust force increases as it approaches a wall, the structure inspection multicopter 100 sticks to a horizontal wall by simply bringing it close.

FIGS. 13 and 14 show how this multicopter 100 for inspecting structures adheres to an oblique or vertical wall surface. The investigator operates the structure inspection multicopter 100 to bring the structure inspection multicopter 100 close to the location to be inspected. When the contact sensor 12 attached to the guard 11 of the multicopter 100 for inspecting structures comes into contact with a wall surface, the contact sensor 12 senses this and rolls over using the contact point as a fulcrum and sticks to the wall surface.

After the structure inspection multicopter 100 is attached to the structure by suction, the structure inspection multicopter 100 conducts inspection at multiple points while changing its position using the wheels 4.

The structure inspection multicopter 100 sticks to the wall so that it will not shift due to wind, and the required power can be reduced by bringing the rotor 1 closer to the wall. This is achieved by providing wheels 4 driven by a moving motor 5 with a reduction gear at the four corners above the rotating surface of the rotor 1, and by setting the distance between the rotor 1 and the wall to less than 50% of the diameter of the rotor 1. This is because they can be kept close to each other, preferably at 20% or less, more preferably at less than 10%.

<When the wall surface is horizontal>
The inspector turns on the mode switch 201 of the control device 200, raises the structure inspection multicopter 100, and attaches the four wheels 4 to the wall surface. The distance between the wall surface formed by the wheel 4 and the rotating surface of the rotor 1 is kept close to 50% or less of the diameter of the rotor 1, more preferably 20% or less, and even more preferably less than 10%. It will be done. Here, the distance between the wall surface and the rotating surface of the rotor 1 formed by the wheels 4 is 10%.

When the contact sensor 12 detects that the structure inspection multicopter 100 is stuck to the wall surface, the CPU 71 reduces the rotation speed of the rotor 1 to reduce power consumption.
Assuming that the load on the wheels 4 required to ensure the frictional force of the wheels 4 is 10% of the weight of four wheels, the thrust force T required per rotor is 1 of the thrust force T0 required during flight. .1 times, resulting in 296.5gf. Since the thrust T is proportional to the square of the rotation speed N of the rotor 1, the rotation speed N of the rotor 1 is
(Formula 1)

is given by Here, N ₀ is the propeller rotation speed when T ₀ is generated. Also, since the required power P is proportional to the cube of the rotation speed N of the rotor 1, the required power P is
(Formula 2)
is given by Here, P ₀ is the required power when T ₀ is generated. The rotation speed N ₀ of the rotor 1 that generates T ₀ when adsorbed to the wall is 7865 rpm from Figure 10, and the rotation speed when it generates a thrust force 1.1 times T ₀ is 8249 rpm from Equation 2. . The required power when generating T ₀ when adsorbed to the wall is 11.98W from FIG. 11. Therefore, the required power P per rotor when a thrust force 1.1 times T ₀ is generated is 13.82 W from Equation 2.

<When the wall surface is tilted or vertical>
This will be explained with reference to the flowchart shown in FIG. Let the inclination of the wall surface be θ degrees. The inspector raises the structure inspection multicopter 100 and brings it close to the inspection location. By turning on the mode switch 201 of the control device 200 (step 151), the rotation speed of the rotor 1 of the multi-copter 100 for structure inspection is increased and raised (step 152), and the multi-copter 100 for structure inspection is suctioned. Enter the mode.

Under this mode, when the contact sensor 12 mounted on the guard 11 makes contact with the wall surface (step 153), the CPU 71 determines the direction of the wall from the position of the contact sensor 12 that reacted (step 154), and The rotation speed of the rotor 1 is adjusted so that the contact sensor 12 that senses the wall becomes the center of rotation. Specifically, the rotation speed of the rotor 1 that is far from the wall is increased, and the rotation speed of the rotor 1 that is close to the wall is decreased (step 155). The object inspection multicopter 100 is turned over. When the contact sensor 12 located opposite to the contact sensor 12 that first detected the contact senses the contact (step 156), the structure inspection multi-copter 100 stops rolling and the rotor 1 is moved to an appropriate position to adsorb it to the wall surface. (step 157), and the rotor 1 is rotated. The rotation speed N suitable for this adsorption is determined as follows.

The vertical component _Fv and the parallel component _Fh of the force W due to the weight of the multicopter 100 for inspecting structures are given by the following equations.

F _v = W sin θ (Formula 3)
F _h =Wcosθ (Formula 4)
Therefore, if the thrust generated by one rotor 1 is T, the load F that one wheel 4 receives is F=T-F _v /4 (Formula 5)
is given by The frictional force F _f generated by this F is given by the following equation, where μ is the friction coefficient between the wheel and the wall surface.

F _f =μF (Formula 6)
Since 4 times the frictional force F _f must be greater than the parallel component F _h of W, the following equation holds.
4F _f >F _h (Formula 7)
From equations 3 to 7, the following equations are obtained.

4μ(T-Wsinθ/4)>Wcosθ (Formula 8)
This equation is transformed to obtain the following equation.
(Formula 9)

From this equation, when μ is 0.8 and θ is 45 degrees, the thrust T generated by one rotor 1 is 428.8 gf. Similarly to when the wall surface is horizontal, the propeller rotation speed N when generating thrust T is 9921 rpm, and the required power per rotor at that time is 24.04 W.

FIG. 16 shows a flowchart when moving away from the wall surface.
By turning off the mode switch 201 (step 161), the structure inspection multicopter 100 enters the detachment mode. Based on the information from the acceleration sensor, the CPU 71 calculates the aircraft attitude, calculates the optimal control method to level the tilted aircraft, adjusts the rotation speed of the rotor 1 (step 162), and controls the structure inspection multicopter 100. is rolled over to make it horizontal (step 163).

<Inspection and movement>
FIG. 17 shows a flowchart for changing direction. The inspector takes the X-axis in the longitudinal direction of the structure and the Y-axis in the direction perpendicular to this. If the control device 200 is operated in a direction (yaw) exceeding the threshold value for a certain period of time (steps 172, 173) while remaining in the adsorption mode (step 171), the direction change mode is entered, and a command signal from the CPU 71 is issued to the servo motor 81. Then, the direction of the gimbal 6 on which the wheels 4 and the moving motor 5 with reduction gear are mounted is changed from the state shown in FIG. 18 to the state shown in FIG. 19 (step 174). The inspector rotates the structure inspection multicopter 100 in the horizontal direction (step 175), and aligns the longitudinal direction of the structure inspection multicopter 100 with the X axis. Thereafter, it waits for another command (step 176).

Using the hammering sound inspection device 83 or camera 84 mounted on the multicopter 100 for inspecting structures, the adsorbed location is inspected.

FIG. 20 shows a flowchart when moving in the front-back direction. While the suction mode remains (step 201), if a forward/backward movement operation exceeding a threshold value is performed using the control device 200 for a certain period of time, the forward/backward movement mode is entered (steps 202, 203), and a command signal from the CPU 71 is issued to the servo motor 81. , the wheels 4 are oriented in the state shown in FIG. 18 (step 204) and moved in the front-back direction (step 205). The CPU 71 measures the moving distance using a rotary encoder 82 provided in the moving motor 5 with a reduction gear, and records the position in the SSD 85 . At this position after the movement, an inspection is performed using the tapping sound inspection device 83 and the camera 84, and the inspection results are recorded in the SSD 85. Thereafter, it waits for another command (step 206).
FIG. 21 shows a flowchart for moving in the left-right direction. While the adsorption mode remains (step 211), if a horizontal movement operation exceeding a threshold value is performed using the control device 200 for a certain period of time, the system enters the horizontal movement mode (steps 212, 213), and a command signal from the CPU 71 is issued to the servo motor 81. , the wheels 4 are oriented as shown in FIG. 22 and moved in the left-right direction (steps 214, 215). The CPU 71 measures the moving distance using a rotary encoder 82 provided in the moving motor 5 with a reduction gear, and records the position in the SSD 85 . At this position after the movement, an inspection is performed using the tapping sound inspection device 83 or the camera 84, and the inspection results are recorded in the SSD 85. Thereafter, it waits for another command (step 216).
This movement and inspection in the X (back and forth) direction and Y (left and right) direction is repeated.

The structure inspection multicopter according to the present invention can be configured as follows regarding movement and inspection.

(1) A multicopter for structure inspection whose upper side sticks to the wall surface of the structure to be inspected due to the thrust of the rotor during inspection, and has four wheels arranged concentrically on the upper side, and each of the wheels. a rotation holding member rotatably held around a vertical axis of the aircraft body; a first rotational drive unit that rotationally drives each of the wheels around the vertical axis of the aircraft body; and a rotational drive unit that drives each of the wheels to rotate about the axis of the wheel. a second rotary drive unit that rotates the structure inspection multicopter around a vertical axis of the aircraft body, and a control that controls the first rotation drive unit so that each of the wheels runs along a concentric circle when the structure inspection multicopter is rotated around a vertical axis of the aircraft body; It is equipped with a section.

(2) In the multicopter for structure inspection according to (1), when the control unit moves the multicopter for structure inspection in one direction along a wall surface, each of the wheels moves in a circular direction in the moving direction. The first rotary drive section is controlled so that the first rotary drive section travels along the following directions.

(3) The multicopter for structure inspection according to (1) or (2), wherein the rotation holding member is a gimbal that holds the wheels and the second rotation drive unit rotatably around the vertical axis of the aircraft body. The first rotational drive section is a servo motor.

<Collection>
When the inspector turns off the mode switch 201 of the control device 200, the structure inspection multicopter 100 returns to the horizontal position and leaves the wall. Thereafter, the multicopter 100 for structure inspection is guided to the ground by the inspector and lands. The inspector extracts the SSD 85 from the structure inspection multicopter 100 and collects the inspection result data.

<Others>
The present invention is not limited to the above-described embodiments, and can be implemented with various modifications and applications within the scope of the technical idea of the present invention. The scope of such modifications and applications also falls within the technical scope of the present invention.

For example, in the above embodiment, a wheel is used as an example of the holding member, but the present invention is not limited to wheels, and for example, a rod-shaped member, a ring-shaped member, or the like may be used as the holding member. When using rod-shaped members, it is preferable to use three members to ensure horizontality with the wall. When using a ring-shaped member, it is necessary to provide a space for introducing horizontal airflow into the blade when adhering to a wall.

1: Rotor 2: Motor 3: Rotor support 4: Wheel 5: Movement motor with reduction gear 6: Gimbal 7: Inspection device 8: Main body 9: Wheel support 10: Guard support 11: Guard 12: Contact sensor 71: CPU
72 : Receiver 73 : Gyro sensor 74 : Acceleration sensor 75 : Battery 81 : Servo motor 82 : Rotary encoder 83 : Hammering sound inspection device 84 : Camera 100 : Multicopter for structure inspection 200 : Control device 201 : Mode switch

Claims (13)

A multi-copter for structural inspection whose upper side sticks to at least the lower surface of the wall surface of the structure to be inspected due to the thrust of the rotor during inspection,
During the inspection , by keeping the distance between the rotating surface of the rotor and the wall surface of the structure to be inspected close to 10% or less of the radius of the rotor, the closer the rotor is to the wall surface, the more required. a holding member configured to reduce the energy consumption of the rotor by utilizing the effect of reducing the power generated by the rotor ;
The rotor is configured to maximize static thrust. A multicopter for structural inspection. The structure inspection multicopter according to claim 1,
The holding member is constituted by wheels for running on the wall surface of the structure to be inspected. The multicopter for structure inspection. The structure inspection multicopter according to claim 2,
Equipped with a gyro sensor that detects the angle of the multicopter for structural inspection,
When stuck to the wall surface of the structure to be inspected, the frictional force between the wall surface and the wheels generated by pressing the wheels against the wall surface is greater than or equal to the magnitude that fixes the aircraft body in a fixed position on the wall surface. A multicopter for structural inspection, wherein the rotation speed of the rotor is adjusted according to the angle of the aircraft detected by the gyro sensor so as to generate thrust. The structure inspection multicopter according to claim 2 or 3,
comprising four rotors,
A multicopter for structural inspection, which is equipped with a guard containing the four rotors. The structure inspection multicopter according to claim 4,
A multicopter for inspecting structures, comprising: a plurality of contact sensors arranged along the outer periphery of the guard. The structure inspection multicopter according to claim 5,
When any one of the plurality of contact sensors detects contact, the rotation of the four rotors is controlled so as to overturn the aircraft using the contact point of the contact sensor that detected the contact as a fulcrum. For structure inspection. Multicopter. The structure inspection multicopter according to any one of claims 4 to 6,
A multicopter for structural inspection, comprising four of the wheels arranged concentrically. The structure inspection multicopter according to claim 7,
a rotational holding member that rotatably holds each of the wheels around a vertical axis of the aircraft body;
and a rotational drive unit that rotates each of the wheels around a vertical axis of the aircraft body,
When rotating the structure inspection multicopter around the vertical axis of the structure inspection multicopter, the rotation driving section is controlled so that each of the wheels runs along a concentric circle. The structure inspection multicopter according to any one of claims 2 to 8,
comprising a rotary encoder that measures the rotation of the wheel,
A multicopter for inspecting structures that measures a distance traveled by the aircraft based on measurement results obtained by the rotary encoder, and calculates an inspection position based on the measurement results. A multicopter for inspecting structures according to any one of claims 1 to 9,
A multicopter for inspecting a structure, comprising an inspection device for inspecting a wall surface of the structure. The structure inspection multicopter according to claim 10,
A multicopter for inspecting structures, wherein the inspection device is a hammering inspection device. The structure inspection multicopter according to claim 10,
A multicopter for inspecting structures, wherein the inspection device is a camera. The structure inspection multicopter according to claim 1,
four wheels arranged concentrically on the upper side;
a rotational holding member that rotatably holds each of the wheels around a vertical axis of the aircraft body;
a first rotational drive unit that rotationally drives each of the wheels around a vertical axis of the aircraft body;
a second rotational drive unit that rotationally drives each of the wheels relative to the axis of the wheel;
and a control unit for controlling the first rotary drive unit so that each of the wheels runs along a concentric circle when the multicopter for structure inspection rotates around the vertical axis of the aircraft body. Multicopter.

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