Mobile device

Abstract

The present invention provides a mobile device that can stably adhere to the surface of a magnetic material while suppressing damage to the surface of the magnetic material during movement. [Solution] The mobile device is a mobile device that travels on the surface of a magnetic material, and comprises a main body (housing 100), drive units 101 provided at least on both sides of the main body and connected to the main body via a link mechanism, and attracted to the surface of the magnetic material by magnetic force, and auxiliary magnets 204 provided on the drive unit 101 at a distance from the surface of the magnetic material to assist the attraction of the drive unit 101 to the surface of the magnetic material.

Description

Technical Field

[0001] The present disclosure relates to a mobile device. In particular, the present disclosure relates to a mobile device used for inspecting defects such as wall thickness reduction and cracks generated by corrosion or damage of a magnetic body such as a steel structure.

Background Art

[0002] In hollow steel structures such as pipes, tanks, gas holders, or chimneys, corrosion or damage may occur. Various inspection methods for inspecting defects such as wall thickness reduction and cracks generated at this time are known. As a method for inspecting a wide range of inspection target members, for example, Patent Document 1 discloses a method using an inspection device that travels while adsorbing to the surface of a steel structure. However, in the inspection device shown in Patent Document 1, the position of the magnet crawler is fixed with respect to the inspection device body. Therefore, depending on the curvature of the steel structure, the ground contact area of the magnet crawler becomes small. As a result, stable travel of the inspection device is difficult.

[0003] In order to solve this problem, for example, Patent Documents 2 and 3 disclose an inspection device in which magnetic wheels are connected to a main body portion via a link mechanism (articulated joint, hinge). The magnetic wheels of this inspection device can tilt with respect to the main body portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the inspection devices described in Patent Documents 2 and 3, the magnetic wheels are tiltable relative to the main body. Therefore, the angle of the magnetic wheels can be changed to match the curvature of the object being inspected, allowing for the handling of various objects. However, in the inspection devices described in Patent Documents 2 and 3, the object being inspected is attracted only by the magnetic force of the magnetic wheels. As a result, the contact pressure (surface pressure) between the magnetic wheels and the surface of the object being inspected becomes strong, and there is a risk that the magnetic wheels may scratch the surface of the object being inspected during operation. Furthermore, there are limitations to relying solely on the magnetic force of the magnetic wheels, and it is difficult to increase the magnetic force.

[0006] In view of the above facts, this disclosure aims to provide a mobile device that can stably adhere to the surface of a magnetic material and suppress damage to the surface of the magnetic material during travel. [Means for solving the problem]

[0007] (1) A mobile device according to one embodiment of the present disclosure, A mobile device that travels on the surface of a magnetic material, The main body of the device, At least one drive unit is provided on both sides of the main body of the device, connected to the main body of the device via a link mechanism, and is attracted to the surface by magnetic force, The drive unit is provided with an auxiliary magnet that is spaced apart from the surface and assists in the attraction of the drive unit to the surface.

[0008] (2) As one embodiment of the present disclosure, in (1), The drive unit includes a magnet-embedded crawler with a permanent magnet embedded in its surface.

[0009] (3) As one embodiment of the present disclosure, in (2), The auxiliary magnet is mounted on the rotating shaft of the magnet-embedded crawler and is rotatable together with the magnet-embedded crawler.

[0010] (4) In one embodiment of the present disclosure, in (1) to (3), The aforementioned linkage mechanism consists of a hinge and a length-adjustable damper.

[0011] (5) In one embodiment of the present disclosure, in (1) to (4), Auxiliary wheels are provided at the lower part of the main body of the device, which are height-adjustable relative to the main body of the device and make contact with the surface.

[0012] (6) As one embodiment of the present disclosure, in (5), The main body of the apparatus is provided with an inspection device for inspecting the magnetic material, spaced apart from the surface, and the height of the inspection device relative to the surface can be adjusted in accordance with the auxiliary wheels. [Effects of the Invention]

[0013] The mobile device of this disclosure can be stably adsorbed to the surface of a magnetic material, and can also suppress scratching of the surface of the magnetic material during travel. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is an external view of a mobile device in one embodiment of the present disclosure. [Figure 2A] Figure 2A is a front view of a mobile device in one embodiment of the present disclosure, shown attached to a flat surface. [Figure 2B] Figure 2B is a front view of a movable device in one embodiment of the present disclosure, attached to a curved surface in the direction of the pipe axis. [Figure 3A] Figure 3A is a side view of a mobile device in one embodiment of the present disclosure, shown attached to a flat surface. [Figure 3B] Figure 3B is a side view of a mobile device in one embodiment of the present disclosure, attached circumferentially to a curved surface. [Figure 4] Figure 4 is a diagram showing the storage section of an inspection device provided in a mobile device according to one embodiment of the present disclosure. [Figure 5] Figure 5 is a front view and a side view of a magnet-embedded crawler in one embodiment of the present disclosure. [Figure 6] FIG. 6 is a graph of flaw detection results using the mobile device in one embodiment of the present disclosure.

Embodiments for Carrying out the Invention

[0015] Hereinafter, a mobile device according to an embodiment of the present disclosure will be described with reference to the drawings.

[0016] (Overall Structure) As shown in FIG. 1, the mobile device of the present embodiment is a device that travels on the surface of a magnetic body, and includes a device main body part (housing 100) and a drive part 101. The device main body part (housing 100) and the drive part 101 are connected to each other via a link mechanism. In the present embodiment, the magnetic body is, for example, a steel structure such as a pipe, a tank, a gas holder, or a chimney, and particularly a hollow steel structure having a curved surface. In this specification, the surface refers to the outer peripheral surface or the inner peripheral surface of the hollow structure.

[0017] (Device Main Body Part (Housing 100)) As shown in FIG. 1, in the present embodiment, the housing 100 of the mobile device is composed of two front and rear housing parts 102 and a central housing part 103. Further, as shown in FIG. 2A, the central housing part 103 has an inspection device 206 and auxiliary wheels 205 fixed to the inspection device 206.

[0018] The two front and rear housing parts 102 and the central housing part 103 are arranged in the traveling direction of the mobile device. Also, the front and rear housing parts 102 and the central housing part 103 are connected to each other by a link mechanism. As a result, as shown in FIG. 3A, when traveling on a flat magnetic body surface, the front and rear housing parts 102 and the central housing part 103 become parallel to the magnetic body surface and can travel along the plane. Further, as shown in FIG. 3B, even when traveling on a magnetic body surface curved in the traveling direction, the front and rear housing parts 102 can travel along the curved surface by inclining with respect to the central housing part 103 along the curved surface.

[0019] The two front and rear housing sections 102 and the central housing section 103 house, for example, a battery for supplying power to various parts of the mobile device and a control device that enables wireless communication with various parts of the mobile device. The housed battery can supply power to the drive motor of the drive unit 101, the inspection device 206, and the control device. The control device controls the drive motor and outputs inspection data from the inspection device 206. By communicating wirelessly from the control device to a remote control PC (notebook PC, etc.), the mobile device can be communicated and controlled wirelessly from a remote location. Here, communication from the control device to the control PC (notebook PC, etc.) may be wireless or wired. As shown in Figure 4, the inspection device 206 is housed inside the central housing section 103. The sensor portion of the inspection device 206 is exposed at the bottom of the central housing section 103 and is mounted so as to be separated from the magnetic surface.

[0020] (Drive unit 101) As shown in Figure 1, in this embodiment, two drive units 101 are provided on each side of the housing 100 (a total of two). Also, as shown in Figures 2A and 3A, the drive unit 101 has two magnet-embedded crawlers 202, a handle 203, an auxiliary magnet 204, a sliding frame 300, and a length-adjustable intermediate turnbuckle 301. The two magnet-embedded crawlers 202 are arranged side by side in the direction of travel of the moving device. The drive unit 101 and the front and rear housing sections 103 are connected by a link mechanism consisting of a length-adjustable damper 200 and a hinge 201.

[0021] As shown in Figure 1, the moving device of this embodiment is equipped with two drive units 101. The two drive units 101 each have the same structure and are independent of each other. Therefore, each drive unit 101 can perform different operations simultaneously.

[0022] Figures 2A and 2B show front views of the mobile device when it is attached to a flat surface and a curved surface perpendicular to the direction of travel, respectively. As shown in Figure 2A, when the mobile device travels on a flat magnetic surface, the housing 100 and the drive units 101 provided on both sides of the housing 100 are parallel to the magnetic surface. As a result, the mobile device can travel along the magnetic surface. Also, as shown in Figure 2B, when the mobile device travels on a curved magnetic surface perpendicular to the direction of travel, the drive units 101 on both sides of the housing 100 are inclined relative to the housing 100 along the curved surface. As a result, the mobile device can travel along the curved surface.

[0023] Figures 3A and 3B show side views of the mobile device when attached to a flat surface and a curved surface curved in the direction of travel, respectively. As shown in Figure 3A, when the mobile device travels on a flat magnetic surface, the housing 100 and the drive units 101 provided on both sides of the housing 100 are parallel to the magnetic surface. As a result, the mobile device can travel along the magnetic surface. Also, as shown in Figure 3B, when the mobile device travels on a curved magnetic surface that is curved in the direction of travel, the two magnet-embedded crawlers 202 located in front of and behind the drive unit 101 are inclined relative to the housing 100 along the curved surface. As a result, the mobile device can travel along the curved surface.

[0024] (Magnet-embedded crawler 202) Figure 5 shows enlarged front and side views of the magnet-embedded crawler 202 provided by the drive unit 101. As shown in Figures 3A and 5, the magnet-embedded crawler 202 has a permanent magnet 502 embedded in the rubber crawler 500 on the surface, and a timing belt 501 and a length-adjustable relay turnbuckle 301 on the underside. Also, as shown in the side view of Figure 5, in this embodiment, the magnet-embedded crawler 202 has a roughly triangular shape and contacts the pulley on the drive unit 101 at three points.

[0025] The magnet-embedded crawler 202 ensures an attractive force to the magnetic material surface using the permanent magnet 502. Because the magnet-embedded crawler 202 contacts the magnetic material surface with its rubber portion, it can suppress the occurrence of scratches on the magnetic material surface. In addition, the magnet-embedded crawler 202 can run stably when contacting curved surfaces, tapered sections, and stepped sections. A timing belt 501 is bonded to the back surface of the magnet-embedded crawler 202. Power from the drive motor is transmitted to this timing belt 501 by a pulley in the drive unit 101. This rotates the magnet-embedded crawler 202 and allows the mobile device to move.

[0026] Thus, the drive unit 101 is composed of a magnet-embedded crawler 202. This allows for a larger contact area between the drive unit 101 and the magnetic surface compared to when the drive unit 101 is composed of wheels, and reduces the contact pressure (surface pressure) on the magnetic surface, thereby suppressing scratches on the magnetic surface during operation.

[0027] As shown in Figure 3A, the magnet-embedded crawler 202 is equipped with a length-adjustable intermediate turnbuckle 301. This allows the contact area of ​​the magnet-embedded crawler 202 with the magnetic surface to be adjusted. The length-adjustable intermediate turnbuckle 301 can be adjusted manually. Each of the two drive units 101 is fitted with a handle 203. Workers can grasp the handles 203 to transport the mobile device, attach it to the magnetic surface, and detach it from the magnetic surface.

[0028] (Auxiliary magnet 204) Furthermore, the drive unit 101 is equipped with an auxiliary magnet 204 to assist in the attraction of the drive unit 101 to the magnetic surface.

[0029] The auxiliary magnets 204 are ring-shaped magnets attached to both the front and rear ends of the lower part of the magnet-embedded crawler 202, that is, to both ends of the two rotating shafts of the magnet-embedded crawler 202. In this embodiment, 16 auxiliary magnets 204 are attached to the mobile device. The lower surface of the magnet-embedded crawler 202 is in contact with the magnetic material surface. On the other hand, the auxiliary magnets 204 are attached at a distance from the magnetic material surface overall. In this embodiment, because the auxiliary magnets 204 are attached to the rotating shafts of the magnet-embedded crawler 202, they can rotate together with the rotation of the magnet-embedded crawler 202. The mobile device may also be equipped with a crossbar (scraper) or the like near the surface of the auxiliary magnets 204. This allows the auxiliary magnets 204 to be removed by rotating them to bring them into contact with the crossbar if foreign matter adheres to them while the mobile device is running. Note that the auxiliary magnets 204 do not necessarily need to rotate together with the magnet-embedded crawler 202. Also, the auxiliary magnets 204 do not need to be attached to the rotating shafts of the magnet-embedded crawler 202. The auxiliary magnet 204 may be a permanent magnet. Furthermore, the auxiliary magnet 204 does not have to be ring-shaped; the magnetic force may be adjusted by changing the position, number, or size of the auxiliary magnet 204.

[0030] (Link mechanism) As shown in Figures 2A and 3A, in this embodiment, the link mechanism is composed of a hinge 201 and a length-adjustable damper 200. The length-adjustable damper 200 can be manually adjusted in length by an extendable ball screw. The length-adjustable damper 200 can be adjusted in length by the curvature of the magnetic surface. This allows the moving device to tilt the drive unit 101 along the curved surface of the magnetic surface. Furthermore, when the moving device is traveling, the length-adjustable damper 200 extends and retracts, allowing the moving device to pivot on curved surfaces and tapered sections. Here, the length-adjustable damper 200 may be a spring damper.

[0031] In this embodiment, the moving device is composed of two front and rear housing sections 102, one central housing section 103, and two drive units 101. The front and rear housing sections 102 and the central housing section 103, as well as the front and rear housing sections 102 and the drive units 101 at both ends thereof, are connected by a hinge 201, which is a link mechanism, and a length-adjustable damper 200. As a result, as shown in Figures 2B and 3B, the front and rear housing sections 102 and the two drive units 101 can be tilted around the central housing section 103 to match the curved surface of the magnetic material.

[0032] (Inspection device 206) As shown in Figure 4, an inspection device 206 for inspecting a magnetic material is provided at the lower part of the central housing 103 of the mobile device. Note that the mobile device does not necessarily need to have the inspection device 206. Alternatively, an inspection device 206 equipped with one or more sensors may be provided at at least one location on the two front and rear housing sections 102 or the central housing section 103 that constitute the mobile device. The inspection device 206 is positioned at a distance from the surface of the magnetic material. In this embodiment, the inspection device 206 is, for example, a flaw detection device for inspecting the surface of the magnetic material, and is specifically composed of an eddy current sensor, a leakage flux sensor, an ultrasonic thickness sensor, or an electromagnetic ultrasonic thickness sensor. Note that the inspection device 206 is not limited to a flaw detection device; it may also be an imaging device for photographing the surface of the magnetic material. There may be one inspection device 206 or multiple inspection devices. If multiple inspection devices 206 are provided, each inspection device 206 may be equipped with multiple similar sensors, or each may be equipped with different sensors and imaging devices.

[0033] In this embodiment, the lower part of the central housing 103 of the mobile device is provided with a plurality of auxiliary wheels 205 (a total of four in this embodiment, located in the front, back, left, and right directions) that can adjust the height of the inspection device 206 relative to the magnetic surface. The height of the auxiliary wheels 205 can be manually adjusted according to the height between the lower surface of the central housing 103 of the mobile device and the magnetic surface, allowing the auxiliary wheels 205 to make contact with the magnetic surface. This stabilizes the posture of the central housing 103, in which the inspection device 206 is incorporated, when the mobile device is in motion. The height of the auxiliary wheels 205 may be adjustable by replacing them with auxiliary wheels 205 of different sizes. The auxiliary wheels 205 may also be made of resin such as urethane.

[0034] Furthermore, one or both ends of the inspection device 206 are fixed to the auxiliary wheels 205. This allows the height or angle of the inspection device 206 to change in accordance with the height of the auxiliary wheels 205 when the height of the auxiliary wheels 205 is adjusted. In this way, by changing the height or angle of the inspection device 206 according to the height between the lower surface of the central housing 103 and the magnetic material surface (height of the auxiliary wheels 205), the distance between the magnetic material surface and the inspection device 206 (lift-off) can always be kept constant. In addition, the inspection device 206 can perform inspection of the magnetic material stably.

[0035] Furthermore, an encoder can be attached to the drive motor that drives the magnet-embedded crawler 202. This makes it possible to acquire mileage data of the mobile device. In addition, the inspection data from the inspection device 206 and the mileage data can be associated with each other.

[0036] (Testing method) While the aforementioned mobile device is running on the surface of the magnetic material, the inspection device 206, which is incorporated into the housing 100 of the mobile device, can be used to inspect the magnetic material.

[0037] (When traveling on a flat surface) As shown in Figures 2A and 3A, when the mobile device travels on a flat surface of a magnetic material, the magnet-embedded crawler 202 of the drive unit 101 makes contact with the magnetic material surface. Therefore, sufficient frictional force for travel can be obtained through sliding with the magnetic material surface. At this time, the auxiliary magnets 204 at both ends of the magnet-embedded crawler 202 do not contact the magnetic material surface. The auxiliary magnets 204 assist the attractive force of the magnet-embedded crawler 202. In addition, since the auxiliary magnets 204 do not come into contact with the magnetic material surface when traveling, they do not scratch the magnetic material surface.

[0038] Furthermore, the front and rear housing sections 102 and the drive unit 101 of the mobile device are connected by a link mechanism. Since the space between the front and rear housing sections 102 and the drive unit 101 is not rigid, the mobile device can pivot. In addition, the central housing section 103 is in contact with the magnetic surface by auxiliary wheels 205. Therefore, the posture of the central housing section 103 as it travels on the magnetic surface can be stabilized. Also, since the height of the inspection device 206 changes in conjunction with the auxiliary wheels 205, the distance between the inspection device 206 and the magnetic surface can be kept constant when performing an inspection.

[0039] (When traveling on a curved surface) As shown in Figure 2B, when the mobile device travels on a curved surface of a magnetic material that curves perpendicular to the direction of travel, the length of the adjustable damper 200 connecting the front and rear housing sections 102 and the drive unit 101 can be manually adjusted to match the curvature of the magnetic material surface. This causes the drive units 101 on both sides of the housing 100 to tilt relative to the housing 100 along the curved surface of the magnetic material. As shown in Figure 3B, when the mobile device travels on a curved surface of a magnetic material that curves in the direction of travel, the length of the adjustable damper 200 connecting the front and rear housing sections 102 and the central housing section 103 can be manually adjusted to match the curvature of the magnetic material surface. This allows the front and rear housing sections 102 to tilt relative to the central housing section 103 in accordance with the curvature. Furthermore, by adjusting the height of the auxiliary wheels 205 of the central housing section 103 to match the curvature of the magnetic material surface, or by replacing the auxiliary wheels 205, the auxiliary wheels 205 can be brought into contact with the magnetic material surface, thereby stabilizing the posture of the central housing section 103 during travel. The inspection device 206, mounted on the lower part of the central housing 103, changes in height and angle in conjunction with the auxiliary wheels 205. Therefore, the inspection device 206 can maintain a constant distance from the magnetic surface when performing inspections. The front and rear housings 102 and drive unit 101 of the mobile device are connected by a link mechanism. Since the space between the front and rear housings 102 and drive unit 101 is not rigid, the mobile device can pivot.

[0040] Furthermore, by manually adjusting the length of the length-adjustable relay turnbuckle 301 located inside the magnet-embedded crawler 202 of the drive unit 101, the tension of the magnet-embedded crawler 202 can be adjusted to match the curvature of the magnetic surface. The magnet-embedded crawler 202 obtains high frictional force by sliding on the magnetic surface. As a result, the moving device can travel stably.

[0041] The sliding frame 300 of the drive unit 101 can be removed by sliding it in the direction of travel or in the opposite direction of travel. The length-adjustable intermediate turnbuckle 301 is connected by a nut in the center and can therefore be divided into two parts. With the length-adjustable intermediate turnbuckle 301 divided into two parts, the magnet-embedded crawler 202 can be compressed, and the magnet-embedded crawler 202 can be attached and detached while compressed. This makes maintenance of the magnet-embedded crawler 202 easier.

[0042] (Effects and Benefits) According to this embodiment, the magnet-embedded crawler 202 is attracted to the magnetic surface by magnetic force. As a result, the contact surface of the magnet-embedded crawler 202 is reliably attracted to and in contact with the magnetic surface. High frictional force is obtained from the magnetic surface as the magnet-embedded crawler 202 slides. Furthermore, the moving device can travel stably even directly beneath the magnetic surface and over steps. In addition, to assist the attractive force of the magnet-embedded crawler 202, an auxiliary magnet 204 is arranged in the drive unit 101, separated from the magnetic surface. This makes it possible to weaken the attractive force of the magnet-embedded crawler 202 compared to when only the magnet-embedded crawler 202 is attracted to the magnetic surface, thereby suppressing the occurrence of scratches on the magnetic surface during the movement of the moving device. Furthermore, a stable attractive force can be obtained even when the magnetic surface is curved, tapered, or stepped.

[0043] In particular, the tension of the magnet-embedded crawler 202 can be adjusted using the length-adjustable intermediate turnbuckle 301. The tension of the magnet-embedded crawler 202 can be adjusted to match the curved surface of the magnetic material. This allows for higher friction against the magnetic material surface and stable running. The length-adjustable intermediate turnbuckle 301 can be disassembled into two parts in the middle. This facilitates the replacement of the magnet-embedded crawler 202.

[0044] Furthermore, the drive unit 101 of the moving device and the front and rear housing sections 102 are connected by a link mechanism consisting of a hinge 201 and a length-adjustable damper 200. The hinge 201 restricts the tilting of the front and rear housing sections 102 to only the width direction or the direction of travel of the moving device. In addition, the length of the length-adjustable damper 200 can be adjusted to match the curvature and taper of the magnetic material, thereby adjusting the tilting angle of the front and rear housing sections 102. This enables stable driving, pivot turns, and reverse driving even on curved and tapered surfaces of the magnetic material.

[0045] Furthermore, by adjusting the height of the auxiliary wheels 205 attached to the central housing 103, or by replacing the auxiliary wheels 205, the central housing 103 can make contact with the magnetic material surface via the auxiliary wheels 205. This allows for more stable movement compared to when only the drive unit 101 is in contact with the ground. In addition, by changing the height or angle of the inspection device 206 in conjunction with the auxiliary wheels 205, the inspection device 206 can be tilted to conform to the curved and tapered surfaces of the magnetic material surface. This allows the distance (lift-off) between the magnetic material surface and the inspection device 206 to remain constant, enabling stable inspection.

[0046] Furthermore, the two front and rear housing sections 102 and the central housing section 103 house a battery for power supply and a control device that enables wireless communication. Therefore, the mobile device can also be controlled wirelessly. In addition, the mobile device can also be controlled via a wired connection by connecting a power cable or a communication cable to the mobile device.

[0047] (Examples) Figure 6 shows a graph of the flaw detection results when a flaw detection inspection was performed as an example of an inspection, representing one embodiment of the present disclosure. A wireless mobile device was attached in the axial direction to the surface of a magnetic pipe with a pipe size of 1200A according to Japanese Industrial Standards (JIS) A designation, and the wireless mobile device traveled in a straight line while performing flaw detection. An encoder was attached to the drive motor that drives the magnet-embedded crawler 202, and the inspection data and travel distance data were correlated. In this case, the mobile device used three eddy current flaw detection sensors as the inspection device 206. From the flaw detection results in Figure 6, detection signals were obtained for each travel distance (pipe length). When traveling over the bead, which is the welded joint of the pipe, a large detection signal value (change in eddy current distribution) was detected. Also, when traveling over the area around the thinning of the pipe wall, a large detection signal value (change in eddy current distribution) was detected.

[0048] While embodiments of this disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art will find it easy to make various modifications or alterations based on this disclosure. Therefore, it should be noted that these modifications or alterations are within the scope of this disclosure. For example, each component can be divided into multiple components or combined into one. [Explanation of Symbols]

[0049] 100 cabinets 101 Drive unit 102 Front and rear casing 103 Central housing section 200 Length-Adjustable Damper 201 Hinge 202 Magnetic Crawler 203 Handle 204 Auxiliary Magnets 205 Auxiliary wheels 206 Inspection equipment 300 sliding frame 301 Length-adjustable relay turnbuckle 500 Rubber Crawler 501 Timing belt 502 Permanent Magnet

Claims

1. A mobile device that travels on the surface of a magnetic material, The main body of the device, At least one drive unit is provided on both sides of the main body of the device, connected to the main body of the device via a link mechanism, and is attracted to the surface by magnetic force, A moving device comprising the drive unit and an auxiliary magnet provided at a distance from the surface to assist in the attraction of the drive unit to the surface.

2. The mobile device according to claim 1, wherein the drive unit comprises a magnet-embedded crawler having a permanent magnet embedded on its surface.

3. The mobile device according to claim 2, wherein the auxiliary magnet is provided on the rotating shaft of the magnet-embedded crawler and is rotatable together with the magnet-embedded crawler.

4. The moving device according to any one of claims 1 to 3, wherein the link mechanism comprises a hinge and a length-adjustable damper.

5. The mobile device according to claim 1 or 2, wherein the lower part of the main body of the device is provided with auxiliary wheels that are height-adjustable relative to the main body of the device and that make contact with the surface.

6. The mobile device according to claim 5, wherein the main body of the device is provided with an inspection device for inspecting the magnetic material at a distance from the surface, and the height of the inspection device relative to the surface can be adjusted in accordance with the auxiliary wheels.

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