In-pipe mobile robot

Abstract

To provide an in-pipe mobile robot capable of easily pulling out a robot body from a pipe when an abnormality occurs. [Solution] An in-pipe mobile robot equipped with a robot body 10, the in-pipe mobile robot having a fluid supply source 21 connected to a plurality of telescopic units and a control device 22 connected to the fluid supply source 21, the control device 22 having a control unit 22a and a mode switching unit 22b that switches the control mode between a normal movement mode and an escape mode, the control unit 22a controlling the operation of the fluid supply source 21 in the normal movement mode so that the plurality of telescopic units alternately transform between a fully expanded state and a natural state and perform peristaltic movement, and in the escape mode controlling the operation of the fluid supply source 21 so that the plurality of telescopic units transform between a non-fully expanded state and a slightly expanded state or a natural state.

Description

Technical Field

[0001] The present invention relates to an in-pipe moving robot that moves inside a pipe.

Background Art

[0002] For example, an in-pipe moving robot configured to move inside a meandering pipe such as an air duct for an air conditioner provided in an office building, a factory, a detached house, etc. is known. Such an in-pipe moving robot is used for various purposes such as inspection and cleaning inside the pipe.

[0003] Conventionally, as such an in-pipe moving robot, there is known one provided with a plurality of expansion and contraction units that expand in the radial direction and contract in the axial direction when fluid is supplied respectively, and configured to move inside the pipe by the plurality of expansion and contraction units performing peristaltic motion in a pattern (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When performing an inspection inside a pipe using such an in-pipe moving robot, if the in-pipe moving robot cannot escape from the pipe by itself due to an abnormality occurring in the robot body, etc., it is necessary to pull a traction member such as a harness connected to the robot body from outside the pipe to pull out the in-pipe moving robot from the pipe.

[0006] However, the telescopic unit provided on the robot body is configured, for example, by a cylindrical elastic body with many fiber bundles arranged along the axial direction, so that it can bend axially but is difficult to stretch, and when the telescopic unit bends along the bent portion of the pipe, pleats due to slack occur on the inner peripheral portion of the telescopic unit. Therefore, if the bent portion of the pipe is, for example, a molded product made of synthetic resin with an edge on the inner peripheral surface that follows the parting line of the mold, when pulling the towing member to withdraw the intra-pipe mobile robot from the pipe, there is a problem in that the pleats formed in the telescopic unit may get caught on the edge on the inner peripheral surface of the bent portion of the pipe, making it difficult to withdraw the intra-pipe mobile robot from the pipe.

[0007] The present invention has been made in view of the above problems, and its object is to provide an in-pipe mobile robot that can easily pull out the robot body from the pipe when an abnormality occurs. [Means for solving the problem]

[0008] The in-pipe mobile robot of the present invention comprises a robot body having at least three telescopic units that expand radially and contract axially when supplied with fluid, and is configured to move inside a pipe by the telescopic units performing peristaltic movement in a pattern, the in-pipe mobile robot comprising: a fluid supply source individually connected to each of the plurality of telescopic units by piping; and a control device connected to the fluid supply source, the control device comprising: a control unit that controls the operation of the fluid supply source; and a mode switching unit that switches the control mode of the control unit to the fluid supply source between a normal movement mode and an escape mode, and in the normal movement mode, the control unit controls the operation of the fluid supply source so that the plurality of telescopic units perform the peristaltic movement by alternately deforming in a pattern between a fully expanded state in which they expand radially and a natural state in which they do not expand, and in the escape mode, the plurality of telescopic units perform the peristaltic movement in a pattern at an internal pressure lower than that of the fully expanded state. so as to have a diameter that is not held on the inner peripheral surface of the tubeThe device is characterized in that it is configured to control the operation of the fluid supply source so that the device transforms between a non-fully expanded state in which the device expands radially, and a slightly expanded state in which the device expands radially at an internal pressure lower than that of the non-fully expanded state, or the natural state.

[0009] The in-pipe mobile robot of the present invention comprises: A robot body comprising at least three expansion and contraction units that expand radially and contract axially when fluid is supplied to each of them, and a pipe-internal movement robot configured to move inside the pipe by the expansion and contraction units moving in a pattern by peristaltic motion, a fluid supply source individually connected to each of the plurality of expansion and contraction units by piping, and a control device connected to the fluid supply source, a traction device that traction members connected to the robot body in a direction to pull the robot body out of the pipe; and a traction force detector that measures a traction force applied to the traction member, The control device has a control unit that controls the operation of the fluid supply source, and a mode switching unit that switches the control mode of the fluid supply source by the control unit between a normal movement mode and an escape mode. In the normal movement mode, the control unit controls the operation of the fluid supply source so that the plurality of expansion and contraction units deform alternately between a fully expanded state in which they expand radially and a natural state in which they do not expand in a pattern to perform the peristaltic motion. In the escape mode, the control unit controls the operation of the fluid supply source so that the plurality of expansion and contraction units deform in a pattern between an incompletely expanded state in which they expand radially at an internal pressure lower than the fully expanded state and a slightly expanded state or the natural state in which they expand radially at an internal pressure lower than the incompletely expanded state. It is configured as such, When the tractive force measured by the tractive force detector becomes equal to or greater than a predetermined value, the mode switching unit automatically switches the control mode from the normal movement mode to the escape mode. characterized in that .

[0010] In the above-described configuration, the intra-pipe mobile robot of the present invention preferably has a traction device that pulls a traction member connected to the robot body in a direction that pulls the robot body out of the pipe, and the control unit is preferably configured to activate the traction device when the control mode is switched from the normal movement mode to the escape mode by the mode switching unit.

[0011] The in-pipe mobile robot of the present invention comprises: A pipe-internal moving robot comprising a robot body having at least three expansion and contraction units that expand radially and contract axially when fluid is supplied to each of them, and configured such that the expansion and contraction units move inside a pipe by performing peristaltic motion in a pattern, having a fluid supply source individually connected to each of the plurality of expansion and contraction units by piping, and a control device connected to the fluid supply source, the control device having a control unit that controls the operation of the fluid supply source, and a mode switching unit that switches the control mode of the fluid supply source by the control unit between a normal movement mode and an escape mode, the control unit controlling the operation of the fluid supply source such that in the normal movement mode, the plurality of expansion and contraction units deform alternately between a fully expanded state in which they expand radially and a natural state in which they do not expand in a pattern to perform the peristaltic motion, and in the escape mode, the plurality of expansion and contraction units deform in a pattern between a non-fully expanded state in which they expand radially at an internal pressure lower than the fully expanded state and a slightly expanded state or the natural state in which they expand radially at an internal pressure lower than the non-fully expanded state. a towing member including a fixed part fixed to the tip of the robot body and a string-like part having one end connected to the fixed part and the other end passing through the interior of the robot body and pulled out from the rear end of the robot body; characterized in that . [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an in-pipe mobile robot that can easily pull out a robot body from a pipe when an abnormality occurs. [Brief explanation of the drawings]

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An in-pipe mobile robot according to the present invention will now be described in detail with reference to the accompanying drawings.

[0015] The in-pipe mobile robot 1 according to one embodiment of the present invention shown in Figure 1 is configured to move inside a winding pipe, such as an air duct for an air conditioning system installed in an office building, factory, detached house, etc.

[0016] The in-pipe mobile robot 1 includes a robot body 10 and a control unit 20.

[0017] The robot body 10 is also called an earthworm-type robot, a peristaltic robot, or the like, and has an elongated shape extending along an axis O. The robot body 10 can move in the axial direction (direction along the axis O) inside the pipe. That is, the robot body 10 can advance inside the pipe. The robot body 10 may also be configured to be able to advance and retreat inside the pipe.

[0018] The robot body 10 is equipped with at least three extension units 11 as a drive source for moving inside the pipe. In this embodiment, the robot body 10 is equipped with seven extension units 11 (only four extension units 11 are shown in FIG. 1). Note that the number of extension units 11 can be changed as needed as long as the robot body 10 is equipped with at least three extension units 11.

[0019] The telescopic unit 11 is also called an artificial muscle. The telescopic unit 11 includes a tubular portion 11a formed of an elastic material such as rubber in a cylindrical shape centered on an axis O. Both axial ends of the tubular portion 11a are closed. A plurality of fiber bundles (not shown) with high tensile strength are arranged inside the tubular portion 11a along the axial direction. This allows the tubular portion 11a to elastically deform so as to expand in the radial direction, but restricts elastic deformation in the axial direction. Therefore, when a fluid such as compressed air is supplied to the inside of the tubular portion 11a, the telescopic unit 11 operates to expand in the radial direction and contract in the axial direction. Furthermore, when the fluid is discharged from the inside of the tubular portion 11a, the telescopic unit 11 contracts in the radial direction due to the elastic force of the tubular portion 11a and extends in the axial direction, returning to its original shape. Each telescopic unit 11 can be operated individually in a pattern.

[0020] Note that the expansion and contraction unit 11 may have various configurations, such as a so-called McKibben type in which the outside of a cylindrical elastic body is covered with fibers knitted in a sleeve shape, as long as it is configured to expand in the radial direction and contract in the axial direction when fluid is supplied.

[0021] Adjacent expansion and contraction units 11 are axially connected to each other by a connecting portion 12. In the present embodiment, the connecting portion 12 is a universal joint (cardan joint). Thereby, the robot body 10 can be bent at the portion of the connecting portion 12. Therefore, when the robot body 10 moves inside the pipe, even if the pipe is bent, the space between adjacent expansion and contraction units 11 can be bent at the connecting portion 12 to move along the bent pipe.

[0022] In the present embodiment, a universal joint is used as the connecting portion 12, but the present invention is not limited to this as long as adjacent expansion and contraction units 11 can be connected so as to be bendable.

[0023] The robot body 10 may be configured to be provided with a plurality of brushes 13 at intervals in the axial direction. In the present embodiment, substantially annular brushes 13 centered on the axis O are provided at both axial ends of each expansion and contraction unit 11. By providing the plurality of brushes 13, the robot body 10 can ensure a state of being supported at the approximate center of the pipe by the plurality of brushes 13 and efficiently move along the pipe when moving inside the pipe. Further, when the robot body 10 moves inside the pipe, the robot body 10 can collect foreign matters (dirt) such as dust attached to the inner peripheral surface of the pipe with the brushes 13 and clean the inside of the pipe.

[0024] Note that in the present embodiment, the robot body 10 is provided with a plurality of brushes 13. However, as long as it has a substantially annular shape centered on the axis O, other members such as flange-shaped or umbrella-shaped synthetic rubber may be provided. Further, the robot body 10 may be configured not to be provided with a plurality of brushes 13 or other members having a substantially annular shape centered on the axis O.

[0025] The robot body 10 may be configured to include a tip portion 14 at an end portion on the forward direction side (the left side in FIG. 1). In the present embodiment, the tip portion 14 is cylindrical with the axis O as the center, and a brush 15 in a substantially annular shape centered on the axis O is provided on the outer peripheral surface of the front end thereof. By providing the brush 15 on the tip portion 14, when moving inside the pipe, it can move along the pipe while being supported at approximately the center of the pipe 2 by the brush 15. Further, by providing the brush 15 on the tip portion 14, when moving inside the pipe 2, foreign matters (dirt) such as dust adhering to the inner peripheral surface of the pipe can be collected by the brush 15 to clean the inside of the pipe.

[0026] In the present embodiment, the brush 15 is provided on the tip portion 14. However, as long as it has a substantially annular shape centered on the axis O, other members such as a flange-shaped or umbrella-shaped synthetic rubber may be provided. Further, the tip portion 14 may be configured such that no other member having a substantially annular shape centered on the brush 15 or the axis O is provided.

[0027] The tip portion 14 can be configured to be connected to the telescopic unit 11 on the foremost side of the robot body 10 by an elastic connection portion 16. The elastic connection portion 16 is constituted by a compression coil spring extending along the axis O, and can be elastically deformed so as to contract along the axis O. Further, the elastic connection portion 16 can be elastically deformed flexibly so as to bend with respect to the axis O. Therefore, when the tip portion 14 approaches a bent portion of the pipe, the elastic connection portion 16 can be elastically deformed so as to bend with respect to the axis O, and thus can bend in a direction along the bent portion.

[0028] The elastic connecting part 16 is not limited to the above-mentioned compression coil spring, but may be any other member such as a rubber tube, as long as it connects the extension unit 11 and the tip end part 14 and is elastically deformable so as to bend with respect to the axis O between the extension unit 11 and the tip end part 14. Also, the extension unit 11 may be configured to be directly connected to the extension unit 11 without being provided with the elastic connecting part 16, or may be configured to be integrally provided at the front end of the extension unit 11.

[0029] The robot body 10 may be configured such that a transparent cover 17 is provided at the tip (front end) of the tip portion 14, and a camera (not shown) is provided inside this cover 17 to photograph the inside of the pipe.

[0030] The control unit 20 controls the operation of the robot body 10 and is connected to the robot body 10 by a harness 18 .

[0031] As shown in FIG. 2, the control unit 20 includes a fluid supply source 21 and a control device 22.

[0032] In this embodiment, the control unit 20 is configured as a single unit in which the fluid supply source 21 and the control device 22 are housed in a single housing 23. Note that the fluid supply source 21 and the control device 22 may not be housed in a single housing 23 and may be configured separately.

[0033] The fluid supply source 21 is individually connected to each of the extension units 11 of the robot body 10 by a plurality of extension pipes 24. Although only three extension pipes 24 are shown in Fig. 2, the fluid supply source 21 is individually connected to each of the corresponding plurality of extension units 11 (seven in this embodiment) by a plurality of extension pipes 24 (seven in this embodiment). The plurality of extension pipes 24 are inserted into tubes that constitute the harness 18 and bundled together.

[0034] The fluid supply source 21 is a device that combines a pressure source, such as an air spacer that supplies compressed air, with a directional controller, such as a solenoid valve. The pressure source may be located outside the housing 23. The fluid supply source 21 supplies fluid from the pressure source to the multiple extension pipes 24 via the directional controller, thereby allowing the fluid to be supplied in individual patterns to the inside (interior) of the tubular portions 11a of the multiple extension units 11 via the multiple extension pipes 24. The fluid supply source 21 also has multiple exhaust valves (not shown) corresponding to the multiple extension pipes 24, respectively. After the supply of fluid to the extension unit 11 is stopped, the fluid inside the tubular portion 11a can be exhausted to the outside through the exhaust valves. For example, a solenoid valve can be used as the exhaust valve. An exhaust valve may be provided for each of the multiple extension pipes 24, separate from the fluid supply source 21. In addition, the fluid supply source 21 may be configured to include multiple pressure sources corresponding to the multiple expansion pipes 24, and to supply fluid directly from the pressure sources corresponding to the multiple expansion pipes 24 without using a directional controller.

[0035] The control device 22 is configured as a computer equipped with a CPU (Central Processing Unit), memory, etc., and is connected to the fluid supply source 21.

[0036] The control device 22 has a control unit 22a and a mode switching unit 22b. The control unit 22a and the mode switching unit 22b are each provided as one function of the control device 22 executed by a computer.

[0037] The control unit 22a controls the operation of the fluid supply source 21. More specifically, the control unit 22a controls the operation of the fluid supply source 21 by outputting to the fluid supply source 21 a command signal obtained by computing a program or the like stored in a memory or the like using a CPU.

[0038] The mode switching unit 22b switches the control mode of the fluid supply source 21 by the control unit 22a between a normal movement mode and an escape mode.

[0039] The mode switching by the mode switching unit 22b may be performed in accordance with a manual operation of a mode switching switch 25 provided in the control unit 20, or may be configured to automatically switch from the normal movement mode to the escape mode when an abnormality is detected in the robot main body 10. The configuration for automatically switching modes will be described in the section describing the control unit 20 according to another modified example shown in FIG. 9.

[0040] The normal movement mode is a mode in which the robot body 10 moves inside a pipe by causing the multiple telescopic units 11 to perform peristaltic movement in a pattern. In the normal movement mode, the control unit 22a controls the operation of the fluid supply source 21 so that the multiple telescopic units 11 perform peristaltic movement by alternately deforming in a pattern between a fully expanded state in which they expand radially and a natural state in which they do not expand. That is, in the normal movement mode, the control unit 22a controls the fluid supply source 21 so that each telescopic unit 11 deforms in a pattern between a fully expanded state in which fluid is supplied from the fluid supply source 21 to the inside of the cylindrical portion 11a through the extension pipe 24 and expands radially, and a natural state in which the fluid supply from the fluid supply source 21 is stopped and the fluid inside the cylindrical portion 11a of the telescopic unit 11 is exhausted to the outside through the exhaust valve, and the internal pressure becomes atmospheric pressure. As a result, in the normal movement mode, the multiple telescopic units 11 as a whole perform peristaltic movement in a pattern, allowing the robot body 10 to move inside the pipe.

[0041] As shown in Figure 3(a), the natural state of the extension unit 11 in the normal movement mode is a state in which no fluid is supplied to the extension unit 11 from the fluid supply source 21, the inside of the tubular portion 11a of the extension unit 11 is at atmospheric pressure, and the extension unit 11 is not expanded but has a cylindrical shape. On the other hand, as shown in Figure 3(b), the fully expanded state of the extension unit 11 in the normal movement mode is a state in which fluid is supplied from the fluid supply source 21 to the inside of the tubular portion 11a of the extension unit 11, and the extension unit 11 is radially expanded to a diameter D1 so that the internal pressure of the tubular portion 11a becomes a predetermined value. The fully expanded state of the extension unit 11 in the normal movement mode is also a state in which the extension unit 11 is expanded to such an extent that it can abut against the inner circumferential surface of the pipe and hold the robot body 10 to the pipe.

[0042] FIG. 4 shows an example of a pattern of peristaltic movement of the multiple telescopic units 11 when the robot body 10 operates in the normal movement mode and moves axially inside the pipe 2 to one side, i.e., when moving forward toward the left side in FIG. 4.

[0043] First, as shown in Fig. 4(a), the leftmost (front) telescopic unit 11 and the second-left telescopic unit 11 in Fig. 4 are expanded in the radial direction to a fully expanded state, and then contracted in the axial direction. The two fully expanded telescopic units 11 each abut over the entire circumference against the inner circumferential surface of the pipe 2. As a result, the robot body 10 is held in the axial direction by the two fully expanded telescopic units 11.

[0044] Next, from the state shown in FIG. 4(a), as shown in FIG. 4(b), the leftmost telescopic unit 11 is returned to its original natural state, and the third telescopic unit 11 from the left is expanded radially to a fully expanded state while contracting axially. At this time, the second telescopic unit 11 from the left abuts against the inner circumferential surface of the pipe 2 and maintains its axial position, so the leftmost telescopic unit 11 contracts radially and extends axially to return to its original shape, and the left end (front end) of the robot body 10 moves leftward from the position shown in FIG. 4(a). Furthermore, since the third telescopic unit 11 from the left expands radially and contracts axially while the second telescopic unit 11 abuts against the inner circumferential surface of the pipe 2 and maintains its axial position, the right end (rear end) of the robot body 10 also moves leftward from the position shown in FIG. 4(a).

[0045] Next, from the state shown in FIG. 4(b), as shown in FIG. 4(c), the second telescopic unit 11 from the left is returned to its original natural state, and the fourth telescopic unit 11 from the left is expanded radially to a fully expanded state while contracting axially. At this time, the third telescopic unit 11 from the left abuts against the inner circumferential surface of the pipe 2 and maintains its axial position, so the second telescopic unit 11 from the left contracts radially and extends axially to return to its original shape, causing the left end (front end) of the robot body 10 to move further leftward from the position shown in FIG. 4(b). Furthermore, since the fourth telescopic unit 11 from the left expands radially and contracts axially while maintaining its axial position while the third telescopic unit 11 abuts against the inner circumferential surface of the pipe 2, the right end (rear end) of the robot body 10 also moves further leftward from the position shown in FIG. 4(b).

[0046] The same procedure is followed to operate the extension units 11 in the above pattern until it reaches the rightmost extension unit 11. Then, when the pattern reaches the rightmost extension unit 11, it returns to the beginning and operates the extension units 11 in the above pattern, as shown in Figure 4(d).

[0047] In this way, in the normal movement mode, the control unit 22a controls the fluid supply source 21 to cause the multiple extension units 11 to perform peristaltic movement in the above-mentioned pattern, which allows the robot body 10 to move forward inside the pipe 2 toward the left in Fig. 4. Also, the control unit 22a controls the fluid supply source 21 to operate the multiple extension units 11 in a pattern that is the left-right reverse of the pattern shown in Fig. 4, which allows the robot body 10 to move backward inside the pipe 2 toward the right in Fig. 3. In other words, in the normal movement mode, the control unit 22a controls the fluid supply source 21 to cause the multiple extension units 11 to perform the above-mentioned peristaltic movement, which allows the robot body 10 to move forward and backward inside the pipe 2.

[0048] The peristaltic movement pattern of the multiple extension units 11 in the normal movement mode is not limited to the above, and may be any other pattern as long as it can move the robot body 10 forward and backward.

[0049] The escape mode is a mode used when, for example, an abnormality occurs in the robot body 10, and the robot body 10 is pulled from the pipe 2 by the harness 18, the towing member, etc., without self-propelling. In the escape mode, the control unit 22a controls the operation of the fluid supply source 21 so that the plurality of telescopic units 11 are transformed in a pattern between an incompletely inflated state in which they are radially inflated at an internal pressure lower than that of the fully inflated state, and a natural state. That is, in the escape mode, the control unit 22a controls the fluid supply source 21 so that each telescopic unit 11 is transformed in a pattern between an incompletely inflated state in which fluid is supplied from the fluid supply source 21 to the inside of the tubular portion 11a through the extension pipe 24 and they are radially inflated at an internal pressure lower than that of the fully inflated state, and a natural state in which the fluid supply from the fluid supply source 21 is stopped and the fluid inside the tubular portion 11a of the telescopic unit 11 is exhausted to the outside through the exhaust valve, and the internal pressure becomes atmospheric pressure.

[0050] In the escape mode, only one selected expansion and contraction unit 11 may be deformed between an incompletely inflated state and a natural state, or a plurality of expansion and contraction units 11 may be sequentially deformed one by one from the front side to the rear side between the incompletely inflated state and the natural state. Alternatively, a plurality of expansion and contraction units 11 that are even-numbered when counted from the front side may be grouped and simultaneously deformed between the incompletely inflated state and the natural state, and then a plurality of expansion and contraction units 11 that are odd-numbered when counted from the front side may be grouped and simultaneously deformed between the incompletely inflated state and the natural state. All the expansion and contraction units 11 may also be simultaneously deformed between the incompletely inflated state and the natural state. Further, in the escape mode, the selected expansion and contraction unit 11 may be alternately deformed a predetermined number of times between the incompletely inflated state and the natural state according to the above pattern.

[0051] Also, in the escape mode, the control unit 22a may be configured to control the operation of the fluid supply source 21 such that the time during which the expansion and contraction unit 11 is in the natural state is longer than the time during which the expansion and contraction unit 11 is in the incompletely inflated state.

[0052] As shown by the solid line in Fig. 5(a), the natural state of the telescopic unit 11 in the escape mode is a state in which no fluid is supplied from the fluid supply source 21 to the telescopic unit 11, the inside of the cylindrical portion 11a of the telescopic unit 11 is at atmospheric pressure, and it has a cylindrical shape without expanding. That is, the natural state of the telescopic unit 11 in the escape mode is the same as the natural state of the telescopic unit 11 in the normal movement mode. On the other hand, as shown in Fig. 5(b), the non-fully inflated state of the telescopic unit 11 in the escape mode is a state in which fluid is supplied from the fluid supply source 21 to the inside of the cylindrical portion 11a of the telescopic unit 11, the internal pressure of the cylindrical portion 11a is set to be lower than that in the fully inflated state, and it has expanded radially to a diameter D2 smaller than the diameter D1 of the telescopic unit 11 in the fully inflated state. The internal pressure of the cylindrical portion 11a in the non-fully inflated state is preferably 90% or less of the internal pressure of the cylindrical portion 11a in the fully inflated state. Thus, the non-fully inflated state of the telescopic unit 11 in the escape mode has a lower internal pressure than the fully inflated state in the normal movement mode, and the diameter D2 of the telescopic unit 11 is smaller than the diameter D1. Therefore, the telescopic unit 11 that has expanded to the non-fully inflated state in the escape mode can easily move axially with respect to the pipe 2 without contacting the inner peripheral surface of the pipe 2 and having its axial position held. Further, the telescopic unit 11 that has expanded to the non-fully inflated state in the escape mode is moderately inflated, so that in a state where the cylindrical portion 11a is bent axially, it is difficult for wrinkles due to slack to occur in the bent inner peripheral side portion.

[0053] In the evacuation mode, the pressure of the fluid supplied from the fluid supply source 21 to the extension unit 11 may be made lower than the pressure of the fluid supplied to the extension unit 11 in the normal movement mode, so that the internal pressure of the tubular portion 11a in the non-fully expanded state is made lower than the internal pressure of the tubular portion 11a in the fully expanded state. Alternatively, in the evacuation mode, the pressure of the fluid supplied from the fluid supply source 21 to the extension unit 11 may be kept the same as the pressure of the fluid supplied to the extension unit 11 in the normal movement mode, but the time for supplying the fluid to the extension unit 11 may be shortened, so that the internal pressure of the tubular portion 11a in the non-fully expanded state is made lower than the internal pressure of the tubular portion 11a in the fully expanded state.

[0054] In the escape mode, the telescopic unit 11 may be alternately deformed between a non-fully inflated state and a slightly inflated state, in which the telescopic unit 11 is radially inflated to a diameter D3 smaller than the diameter D2 by expanding radially at an internal pressure lower than that in the non-fully inflated state. The internal pressure of the tubular portion 11a in the slightly inflated state is preferably 30% or less of the internal pressure of the tubular portion 11a in the fully inflated state. As shown by the two-dot chain line in FIG. 5(a), the slightly inflated state is a state in which the tubular portion 11a is slightly inflated compared to its natural state. With this configuration, even when the telescopic unit 11 is switched from the non-fully inflated state to the slightly inflated state, it is possible to prevent folds 11b due to slack from forming in the inner peripheral portion of the tubular portion 11a.

[0055] In the in-pipe mobile robot 1 of this embodiment, if an abnormality occurs in the robot body 10, the robot body 10 can be pulled from the pipe 2 by pulling the harness 18, towing member, etc. from outside the pipe 2 without allowing the robot body 10 to move on its own.By switching the control mode of the control unit 22a from normal movement mode to escape mode by the mode switching unit 22b, the robot body 10 can be easily pulled out of the pipe 2 even if the bent portion 2a of the pipe 2 is, for example, a molded product made of synthetic resin with an edge 2b on the inner surface that follows the parting line of the mold, as shown in Figure 6.

[0056] That is, as shown in Fig. 6(a), since the cylindrical portion 11a is configured to be bendable but difficult to stretch in the axial direction, when the telescopic unit 11 in the natural state is located at the bent portion 2a of the tube 2, a plurality of folds 11b due to slack are generated in the inner peripheral side portion of the cylindrical portion 11a. Then, when pulling the harness 18, the traction member, etc. from the outside of the tube 2 to pull out the robot body 10 from the tube 2, a force directed toward the inner peripheral side is applied to the telescopic unit 11, so that the folds 11b are strongly caught on the edge 2b of the bent portion 2a of the tube 2 and it becomes difficult to pull out the robot body 10 from the tube 2.

[0057] In contrast, as shown in FIG. 6( b), when the control unit 22a controls the operation of the fluid supply source 21 in the escape mode, the telescopic unit 11 expands to the incompletely inflated state, stretching the folds 11b that were present in the tubular portion 11a in the natural state, and the tubular portion 11a becomes substantially cylindrical without the folds 11b, thereby eliminating the snagging of the telescopic unit 11 on the edge 2b. Furthermore, since the telescopic unit 11 only expands to the incompletely inflated state, which has a smaller diameter than the fully inflated state, the incompletely inflated telescopic unit 11 does not come into contact with the inner circumferential surface of the bent portion 2a of the pipe 2 and is not held by the inner circumferential surface. Therefore, in the escape mode, by pulling the harness 18, the towing member, or the like from outside the pipe 2 when the telescopic unit 11 enters the incompletely inflated state, the robot main body 10 can be moved inside the bent portion 2a of the pipe 2 to a position where the folds 11b will not get caught on the edge 2b when the telescopic unit 11 is in the natural state or the slightly inflated state, as shown in FIG. 6( c). If the folds 11b are not released from being caught on the edge 2b by a single movement, the harness 18, the towing member, etc. can be repeatedly pulled from outside the pipe 2 each time the telescopic unit 11 is repeatedly in the non-fully inflated state in the escape mode, until the interior of the bent portion 2a of the pipe 2 reaches a position where the folds 11b are not caught on the edge 2b when the telescopic unit 11 is in its natural state or in its slightly inflated state. If the interior of the bent portion 2a of the pipe 2 can be moved to a position where the folds 11b are not caught on the edge 2b when the telescopic unit 11 is in its natural state or in its slightly inflated state, the harness 18, the towing member, etc. can then be further pulled from outside the pipe 2, thereby making it possible to easily pull the robot main body 10 out of the pipe 2.

[0058] In the escape mode, for example, based on various information such as the length of the tube 2, the length of the harness 18 drawn into the tube 2, and the video of the inside of the tube 2 taken by the camera, among the telescopic units 11 of the robot body 10 stopped inside the tube 2, if it is possible to grasp which telescopic unit 11 is located at the bent portion 2a of the tube 2, only the telescopic unit 11 that is grasped to be located at the bent portion 2a of the tube 2 may be deformed into an incompletely inflated state and a natural state in the escape mode, while pulling the harness 18, the traction member, etc. from outside the tube 2.

[0059] On the other hand, if it is not possible to grasp which telescopic unit 11 of the telescopic units 11 of the robot body 10 stopped inside the tube 2 is located at the bent portion 2a of the tube 2, the plurality of telescopic units 11 are deformed one by one in order into an incompletely inflated state and a natural state in the escape mode, or a plurality of telescopic units 11 that are even-numbered when counted from the front side are grouped and simultaneously deformed into an incompletely inflated state and a natural state, and then a plurality of telescopic units 11 that are odd-numbered when counted from the front side are grouped and simultaneously deformed into an incompletely inflated state and a natural state, or all the telescopic units 11 are simultaneously deformed into an incompletely inflated state and a natural state, while pulling the harness 18, the traction member, etc. from outside the tube 2.

[0060] As described above, in the in-tube moving robot 1 according to the present embodiment, the operation of the control unit 22a is configured to be switchable between the normal movement mode and the escape mode by the mode switching unit 22b, and in the escape mode, the control unit 22a controls the operation of the fluid supply source 21 so that the plurality of telescopic units 11 are deformed in a pattern into an incompletely inflated state in which they expand radially at an internal pressure lower than the fully inflated state and a slightly inflated state or a natural state in which they expand radially at an internal pressure lower than the incompletely inflated state. Therefore, even when there is an edge 2b at the bent portion 2a of the tube 2, by operating the telescopic unit 11 in the escape mode, it is possible to eliminate the catching of the edge 2b of the telescopic unit 11 and easily pull out the robot body 10 from the tube 2.

[0061] Fig. 7 is a block diagram of the control unit 20 according to a modified example, and Figs. 8(a) and 8(b) are explanatory diagrams showing the display state of the display panel in escape mode. Note that in Figs. 7 and 8, the same reference numerals are used to denote the same members and parts as those described above.

[0062] As shown as a modified example in FIG. 7, the control unit 20 may also be configured to include a display panel 30.

[0063] The display panel 30 has a plurality of indicator lamps 31 corresponding to each of the plurality of extension units 11. Although Fig. 7 exemplarily shows only three indicator lamps 31 corresponding to three extension units 11, the display panel 30 actually has a plurality of indicator lamps 31 (seven in this embodiment) aligned in a straight line corresponding to the plurality of extension units 11 (seven in this embodiment). The arrangement order of the plurality of indicator lamps 31 corresponds to the arrangement order of the plurality of extension units 11 from the front to the rear of the robot body 10.

[0064] The display panel 30 is connected to the control unit 22a. The operation of the display panel 30 is controlled by the control unit 22a such that in the escape mode, a display lamp 31 corresponding to the expansion and contraction unit 11 that has become in an incompletely inflated state with fluid supplied from the fluid supply source 21 is lit. For example, as shown in FIG. 8(a), in the escape mode, when fluid is supplied from the fluid supply source 21 and the foremost expansion and contraction unit 11 of the robot body 10 expands to an incompletely inflated state, the operation of the display panel 30 is controlled by the control unit 22a such that the leftmost display lamp 31 in FIG. 7 corresponding to this foremost expansion and contraction unit 11 is lit. Also, as shown in FIG. 8(b), in the escape mode, when fluid is supplied from the fluid supply source 21 and the second expansion and contraction unit 11 from the front of the robot body 10 expands to an incompletely inflated state, the operation of the display panel 30 is controlled by the control unit 22a such that the second display lamp 31 from the left in FIG. 7 corresponding to this second expansion and contraction unit 11 from the front is lit. Further, although not shown in detail, when a plurality of expansion and contraction units 11 expand to an incompletely inflated state simultaneously, the operation of the display panel 30 is controlled by the control unit 22a such that a plurality of display lamps 31 corresponding to these plurality of expansion and contraction units 11 that have expanded to an incompletely inflated state are lit. In FIG. 7, the lit display lamp 31 is shown as a circle, and the extinguished display lamp 31 is shown as a horizontal bar, but the display method is not limited to these.

[0065] Thus, by adopting a configuration in which the control unit 20 is provided with the display panel 30, in the escape mode, it is possible for the user to recognize which expansion and contraction unit 11 among the plurality of expansion and contraction units 11 has become in an incompletely inflated state by the lighting of the display lamp 31. Therefore, in the escape mode, the user may pull the harness 18, the traction member, etc. from outside the pipe 2 at the timing when the display lamp 31 is lit. As a result, since the expansion and contraction unit 11 is pulled and moves inside the pipe 2 at the timing when the catching on the edge 2b of the expansion and contraction unit 11 is released, the robot body 10 can be efficiently pulled out toward the outside of the pipe 2.

[0066] For example, based on various information such as the length of the tube 2, the length of the harness 18 drawn into the tube 2, and the video of the inside of the tube 2 taken by the camera, when it is possible to determine which telescopic unit 11 of the robot body 10 stopped inside the tube 2 is located at the bent portion 2a of the tube 2, the user can pull the harness 18, the traction member, etc. from outside the tube 2 when the display lamp 31 corresponding to the telescopic unit 11 that is grasped to be located at the bent portion 2a of the tube 2 lights up, and thus can easily pull out the robot body 10 from the tube 2.

[0067] On the other hand, when it is not possible to determine which telescopic unit 11 of the robot body 10 stopped inside the tube 2 is located at the bent portion 2a of the tube 2, the user can easily pull out the robot body 10 from the tube 2 by pulling the harness 18, the traction member, etc. from outside the tube 2 each time any one of the display lamps 31 lights up.

[0068] In the modified example shown in FIG. 7, the control unit 20 is configured to include a speaker 32 in addition to the display panel 30. The speaker 32 is connected to the control unit 22a and is controlled by the control unit 22a to emit an operating sound when at least any one of the plurality of telescopic units 11 expands to an incompletely inflated state in the escape mode.

[0069] In this way, by providing the control unit 20 with the speaker 32, in the escape mode, the user can be made to recognize by the operating sound emitted by the speaker 32 that at least any one of the telescopic units 11 has expanded to an incompletely inflated state. Therefore, in the escape mode, the user may pull the harness 18, the traction member, etc. from outside the tube 2 at the timing when the speaker 32 emits the operating sound. As a result, since the telescopic unit 11 is pulled at the timing when the snagging on the edge 2b of the telescopic unit 11 is eliminated and moves inside the tube 2, the robot body 10 can be efficiently pulled out toward the outside of the tube 2.

[0070] The control unit 20 may be configured to include only one of the display panel 30 and the speaker 32. The display panel 30 of the control unit 20 is not limited to the configuration including the plurality of indicator lamps 31 described above, but may also be configured to include a visual display, such as an LCD (liquid crystal display), that displays a visual indication of which of the extension units 11 is in an incompletely inflated state.

[0071] Fig. 9 is a block diagram of a control unit according to another modified example, in which the same reference numerals are used to denote the same members and portions as those described above.

[0072] The control unit 20 shown in FIG. 9 as another modified example includes a display panel 30, and the control device 22 has an abnormality detection unit 22c, and is configured so that when the abnormality detection unit 22c detects an abnormality in the robot body 10, the mode switching unit 22b automatically switches the control mode from the normal movement mode to the escape mode.

[0073] More specifically, the control unit 20 as another modified example is equipped with a plurality of pressure sensors 26 that are connected to a plurality of extension pipes 24 corresponding to a plurality of extension units 11, respectively, and measure the internal pressure of the corresponding extension units 11 via the extension pipes 24. Although Fig. 9 shows only three pressure sensors 26 corresponding to three extension pipes 24, the control unit 20 is equipped with a plurality of pressure sensors 26 (seven in this embodiment) corresponding to a plurality of extension pipes 24 (seven in this embodiment).

[0074] A plurality of pressure sensors 26 are respectively connected to the abnormality detection unit 22c, and the abnormality detection unit 22c is connected to the control unit 22a and the mode switching unit 22c. The abnormality detection unit 22c can detect an abnormality of the robot body 10 based on the internal pressure of the expansion and contraction unit 11 input from the pressure sensor 26. For example, when cracks, holes, etc. due to damage occur in the cylindrical portion 11a of the expansion and contraction unit 11, and the internal pressure of the expansion and contraction unit 11 when fluid is supplied from the fluid supply source 21 does not reach the specified pressure in the normal movement mode, the abnormality detection unit 22c determines from the measured value of the internal pressure of the expansion and contraction unit 11 measured by the pressure sensor 26 that the abnormality, that is, the robot body 10 cannot perform a normal movement operation, has occurred.

[0075] When the abnormality detection unit 22c detects an abnormality of the robot body 10, the mode switching unit 22b automatically switches the control mode of the fluid supply source 21 by the control unit 22a from the normal movement mode to the escape mode. That is, when an abnormality occurs in the robot body 10 and it is necessary to pull the robot body 10 out of the pipe 2 by pulling the harness 18, the traction member, etc. from the outside of the pipe 2, the control mode can be automatically switched to the escape mode without the user manually switching the control mode. Therefore, when an abnormality occurs in the robot body 10, the robot body 10 can be more easily pulled out of the pipe 2 without the user manually switching the control mode.

[0076] When the abnormality detection unit 22c detects an abnormality of the robot body 10, the display lamp 31 of the display panel 30 corresponding to the expansion and contraction unit 11 in which the abnormality has occurred may be lit to display the abnormality. In the case shown in FIG. 9, the display lamp 31 of the display panel 30 corresponding to the expansion and contraction unit 11 in which the abnormality has occurred is lit in an × shape. Note that the display lamp 31 is not limited to being lit in an × shape as long as it can display an abnormality, and may be in various lighting states, for example, lit in red.

[0077] Note that when pulling out the robot body 10 from the pipe 2 by pulling the harness 18, the traction member, etc. from the outside of the pipe 2, if the operator feels that it is difficult to pull out the robot body 10 from the pipe 2, the mode switching unit 22b may be configured to manually switch the control mode from the normal movement mode to the escape mode.

[0078] The control unit 20 shown in FIG. 9 further includes a traction device 50 that traction the traction member 40 connected to the robot body 10 in the direction of pulling out the robot body 10 from the pipe 2. In the illustrated case, the traction member 40 is disposed outside the housing 23, but may be incorporated in the housing 23. The traction device 50 may be, for example, an electric winding device that winds up the traction member 40. In this case, the traction device 50 is configured to be able to traction the robot body 10 in the direction of pulling out from the pipe 2 by winding up the traction member 40.

[0079] The control unit 20 shown in FIG. 9 further includes a traction force detector 51. The traction force detector 51 is installed between the first portion 40a of the traction member 40 connected to the robot body 10 and the second portion 40b on the side of the traction device 50, and can measure the traction force applied between the first portion 40a and the second portion 40b, that is, the traction force applied to the traction member 40. The traction force detector 51 may be configured to include, for example, a load cell (not shown). Note that when the traction device 50 is configured to traction the robot body 10 in the direction of pulling out from the pipe 2 by winding up the harness 18, the traction force detector 51 may be provided on the harness 18.

[0080] The traction force detector 51 is connected to the control unit 22a. The control unit 22a is configured to automatically switch the control mode from the normal movement mode to the escape mode by the mode switching unit 22b when the traction force measured by the traction force detector 51 when the traction member 40 or the harness 18 connected to the robot body 10 is traction by the traction device 50 becomes equal to or greater than a predetermined value (for example, 1200 N or more).

[0081] The traction device 50 is connected to the control unit 22a, and its operation is controlled by the control unit 22a.

[0082] For example, the traction device 50 is controlled by the control unit 22a to be activated when the control mode is switched from the normal movement mode to the escape mode by the mode switching unit 22b. Therefore, when the abnormality detection unit 22c detects an abnormality in the robot body 10, the mode switching unit 22b automatically switches the control mode from the normal movement mode to the escape mode and automatically activates the traction device 50. The robot body 10 is pulled in the direction of being pulled out of the pipe 2 by the extension unit 11 expanding to the non-expanded state, thereby releasing the robot body 10 from being caught on the edge 2b of the bent portion 2a of the pipe 2, and the traction member 40 being retracted by the traction device 50. Therefore, when an abnormality occurs in the robot body 10, the control mode is automatically switched to the escape mode and the robot body 10 is pulled out of the pipe 2 without the user having to switch the control mode or pull the robot body 10. Therefore, when an abnormality occurs in the robot body 10, the user can more easily pull the robot body 10 out of the pipe 2 without having to manually switch the control mode or pull the robot body 10.

[0083] The traction device 50 can also be manually activated when pulling the robot body 10 out of the pipe 2. In this case, as described above, when the traction force measured by the traction force detector 51 when the traction device 50 pulls the traction member 40 or harness 18 connected to the robot body 10 reaches a predetermined value or greater (e.g., 1200 N or greater), the control mode is automatically switched from the normal movement mode to the escape mode. Therefore, even when an edge 2b is present at a bent portion 2a of the pipe 2, the robot body 10 is pulled in the direction of being pulled out of the pipe 2 by the traction device 50 reeling in the traction member 40 or harness 19 as the telescopic unit 11 expands to the non-expanded state, thereby releasing the robot body 10 from being caught on the edge 2b at the bent portion 2a of the pipe 2. Therefore, the robot body 10 can be pulled in the direction of being pulled out of the pipe 2 without the user having to manually switch the control mode or perform the pulling operation.

[0084] Fig. 10(a) is a side view of a part of a pipe moving robot provided with a traction member, and Fig. 10(b) is a side view of a part of a pipe moving robot provided with a traction member according to a modified example. In Fig. 10, the same reference numerals are given to the members or parts described above.

[0085] As shown in Fig. 10(a), the pipe moving robot 1 may be configured to have a traction member 40 including a fixing portion 41 fixed to the tip of the robot main body 10 and a string-like portion 42 having one end connected to the fixing portion 41 and the other end drawn out from the rear end of the robot main body 10 through the inside of the robot main body 10.

[0086] In the case shown in Fig. 10(a), the user can pull the string-like portion 42 of the traction member 40 to pull the robot main body 10 inside the pipe 2 and draw it out of the pipe 2.

[0087] The fixing portion 41 is formed, for example, of a steel material, in a disk shape having a diameter larger than the hole or gap through which the string-like portion 42 of the robot main body 10 is inserted. Therefore, even when a part of the robot main body 10 is damaged by the traction force when pulling the traction member 40 to pull the robot main body 10, all parts of the robot main body 10 can be drawn out of the pipe 2 by hooking the damaged member on the fixing portion 41 together with the fixing portion 41.

[0088] As shown in Fig. 10(b), the traction member 40 may be configured such that the string-like portion 42 is divided into a first portion 42a connected to the fixing portion 41 and a second portion 42b connected to the control unit 20, and a first fastening portion 42c connected to the first portion 42a and a second fastening portion 42d connected to the second portion 42b are detachably connected.

[0089] Needless to say, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist thereof.

[0090] For example, the fluid supplied from the fluid supply source 21 to the expansion and contraction unit 11 is not limited to compressed air, and may be other compressible fluids such as nitrogen, or other incompressible fluids such as water.

Explanation of Signs

[0091] 1 In-pipe moving robot 2 Pipe 2a Bending part 2b Edge 10 Robot body 11 Expansion and contraction unit 11a Cylindrical part 11b Fold 12 Connecting part 13 Brush 14 Tip part 15 Brush 16 Elastic connection part 17 Cover 18 Harness 20 Control unit 21 Fluid supply source 22 Control device 22a Control part 22b Mode switching part 22c Abnormality detection part 23 Housing 24 Expansion and contraction pipe 25 Mode switching switch 26 Pressure sensor 30 Display panel 31 Display lamp 32 Speaker 40 Towing member 40a First part 40b Second part 41 Fixed part 42 String-like part 42a First part 42b Second part 42c First fastening part 42d Second fastening part 50 Towing device 51 Towing force detector O Axis D1 Diameter D2 Diameter D3 diameter

Claims

1. A pipe-internal moving robot comprising a robot body having at least three expansion and contraction units that expand radially and contract axially when fluid is supplied to each of them, wherein the expansion and contraction units are configured to move inside a pipe by performing a peristaltic motion in a pattern, a fluid supply source individually connected to each of the plurality of expansion and contraction units by piping, and a control device connected to the fluid supply source, wherein the control device has a control unit that controls the operation of the fluid supply source, and a mode switching unit that switches the control mode of the fluid supply source by the control unit between a normal movement mode and an escape mode, wherein the control unit in the normal movement mode, controls the operation of the fluid supply source such that the plurality of expansion and contraction units deform alternately in a pattern between a fully expanded state in which they expand radially and a natural state in which they do not expand, to perform the peristaltic motion, in the escape mode, controls the operation of the fluid supply source such that the plurality of expansion and contraction units deform in a pattern between an incompletely expanded state in which they expand radially to a diameter that is not held against the inner peripheral surface of the pipe at an internal pressure lower than the fully expanded state, and a slightly expanded state or the natural state in which they expand radially at an internal pressure lower than the incompletely expanded state. The pipe-internal moving robot is characterized by being configured as described above.

2. A pipe-internal moving robot comprising a robot body having at least three expansion and contraction units that expand radially and contract axially when fluid is supplied to each of them, wherein the expansion and contraction units are configured to move inside a pipe by performing a peristaltic motion in a pattern, a fluid supply source individually connected to each of the plurality of expansion and contraction units by piping, a control device connected to the fluid supply source, a traction device that tractionally pulls a traction member connected to the robot body in a direction to pull the robot body out of the pipe, and a traction force detector that measures the traction force applied to the traction member, wherein the control device has a control unit that controls the operation of the fluid supply source, and a mode switching unit that switches the control mode of the fluid supply source by the control unit between a normal movement mode and an escape mode, wherein the control unit in the normal movement mode, controls the operation of the fluid supply source such that the plurality of expansion and contraction units deform alternately in a pattern between a fully expanded state in which they expand radially and a natural state in which they do not expand, to perform the peristaltic motion, In the escape mode, the operation of the fluid supply source is controlled such that a plurality of the expansion and contraction units are patterned to deform into an incomplete expansion state in which they expand radially at an internal pressure lower than the fully expanded state, and a slightly expanded state or the natural state in which they expand radially at an internal pressure lower than the incomplete expansion state. The in-pipe moving robot is characterized in that when the traction force measured by the traction force detector becomes equal to or greater than a predetermined value, the control mode is automatically switched from the normal movement mode to the escape mode by the mode switching unit.

3. It has a traction device that pulls a traction member connected to the robot body in a direction to pull the robot body out of the pipe. The in-pipe moving robot according to claim 1 or 2, wherein the control unit is configured to activate the traction device when the control mode is switched from the normal movement mode to the escape mode by the mode switching unit.

4. An in-pipe moving robot comprising a robot body having at least three expansion and contraction units that expand radially and contract axially when fluid is supplied to each of them, and configured to move inside the pipe by the expansion and contraction units moving in a peristaltic motion in a pattern. A fluid supply source individually connected to each of the plurality of expansion and contraction units by piping. A control device connected to the fluid supply source. The control device A control unit that controls the operation of the fluid supply source. A mode switching unit that switches the control mode of the fluid supply source by the control unit between a normal movement mode and an escape mode. The control unit In the normal movement mode, the operation of the fluid supply source is controlled such that a plurality of the expansion and contraction units are patterned to alternately deform into a fully expanded state in which they expand radially and a natural state in which they do not expand, to perform the peristaltic motion. In the escape mode, the operation of the fluid supply source is controlled such that a plurality of the expansion and contraction units are patterned to deform into an incomplete expansion state in which they expand radially at an internal pressure lower than the fully expanded state, and a slightly expanded state or the natural state in which they expand radially at an internal pressure lower than the incomplete expansion state. A pipe-internal moving robot further comprising a traction member having a fixing portion fixed to the tip of the robot body and a string-shaped portion having one end connected to the fixing portion and the other end drawn out from the rear end of the robot body through the inside of the robot body.

Images