In-pipe traveling device, control method for in-pipe traveling device, and control program for in-pipe traveling device

Abstract

To provide an in-pipe traveling device which can travel in a pipe line with out-of-plane bending, a control method for the in-pipe traveling device, and a control program for the in-pipe traveling device.SOLUTION: An in-pipe traveling device includes: a first link 10; a second link 20 which is connected to the first link 10; an active joint part 60 which connects the first link 10 with the second link 20; and a first spherical wheel 41, a second spherical wheel 42 and a central wheel 43 which rotate to enable movement of the in-pipe traveling device 100. The first spherical wheel 41 can control the angle around a pipe axis Ps of a pipe line P for a rotational axis 41s of the first spherical wheel 41. The second spherical wheel 42 can control the angle around the pipe axis Ps of the pipe line P for a rotational axis 42s of the second spherical wheel 42. The central wheel 43 can move passively along a rotational axis 43s of the central wheel 43.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an in-pipe traveling device, a control method for an in-pipe traveling device, and a control program for an in-pipe traveling device. [Background technology]

[0002] An in-pipe traveling device equipped with a camera is sometimes used as an inspection device for inspecting the inside of pipelines, including gas pipes. For example, Patent Document 1 discloses an in-pipe traveling device that does not require complex control and is designed to be compact. The in-pipe traveling device of Patent Document 1 has multiple links swingably connected by connecting parts, and allows the device to travel inside the pipeline by rolling elements, while a biasing means brings the rolling elements into contact with the inner wall surface of the pipe. The rolling elements in the in-pipe traveling device of Patent Document 1 are controlled by a single actuator to rotate in the direction in which the in-pipe traveling device advances and in the direction in which the in-pipe traveling device rolls around the pipe axis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-26760 Summary of the Invention [Problem to be solved by the invention]

[0004] The pipeline along which the in-pipe traveling device travels may have a bent section formed by an elbow or the like. In other words, the pipe axis may be curved. In addition, there may be a plurality of elbows provided in succession, and the planes containing the curved pipe axis of the plurality of elbows may be different from each other (out-of-plane bending). In the in-pipe traveling device of Patent Document 1, if three or more links are provided, it becomes geometrically impossible for the device to travel through the aforementioned out-of-plane bent pipeline. Also, in the case of two links, when traveling through a pipeline with out-of-plane bends, the in-pipe traveling device needs to roll rotate about the pipe axis while traveling through the pipeline with out-of-plane bends. However, when attempting to travel through a pipeline with out-of-plane bends, the in-pipe traveling device of Patent Document 1 has a problem in that the rolling body rotates relative to the link of the in-pipe traveling device, making it impossible to proceed through the pipeline.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an in-pipe traveling device capable of traveling through a pipeline with an out-of-plane bend, a control method for an in-pipe traveling device, and a control program for an in-pipe traveling device. [Means for solving the problem]

[0006] <1> An in-pipe traveling device according to a first aspect of the present invention is an in-pipe traveling device that travels inside a pipeline, comprising: a first link provided on one side of the in-pipe traveling device; a second link provided on the other side of the in-pipe traveling device and connected to the first link; an active joint unit that swingably connects the first link and the second link and can actively change an angle between the first link and the second link; and wheels that rotate to enable the in-pipe traveling device to move to the one side and the other side, the wheels comprising a first spherical wheel provided at an end of the one side of the first link and rotatable about a rotation axis, a second spherical wheel provided at an end of the other side of the second link and rotatable about a rotation axis, and a first spherical wheel having a rotation axis extending forward and ... and a central wheel arranged along the rotation axis of the active joint unit, wherein when the active joint unit adjusts an angle between the first link and the second link, the first spherical wheel and the second spherical wheel are in contact with a first inner wall surface of the inner wall surface of the pipeline, and the central wheel is in contact with a second inner wall surface of the inner wall surface of the pipeline that is radially opposed to the first inner wall surface, with the pipeline axis being sandwiched therebetween, the first spherical wheel is capable of controlling an angle about the rotation axis of the first spherical wheel, the second spherical wheel is capable of controlling an angle about the rotation axis of the second spherical wheel about the pipeline axis, and the central wheel is capable of passively moving along the rotation axis of the central wheel.

[0007] According to the first aspect, the first spherical wheel can control the angle around the pipe axis of the pipeline with respect to the rotation axis of the first spherical wheel, and the second spherical wheel can control the angle around the pipe axis of the pipeline with respect to the rotation axis of the second spherical wheel. The central wheel can passively move along the rotation axis of the central wheel. That is, the central wheel can passively move by an external force so as to slide in the circumferential direction on the inner wall surface of the pipeline, in addition to rotating so as to move the intra-pipe traveling device to one side and the other side. With these, for example, when the in-pipe traveling device enters a pipeline with an out-of-plane bend from an in-plane bent pipeline and receives a force in a direction of rotating around the pipeline axis by contacting the inner wall surface of the pipeline with the first spherical wheel, it can be controlled as follows. That is, by controlling the rotation axis of each of the first and second spherical wheels so that they do not rotate around the pipeline axis relative to the link of the in-pipe traveling device (controlling the rotation axis in a direction intersecting the pipeline axis), for example, a part of the in-pipe traveling device, such as only the first spherical wheel, does not rotate around the pipeline axis, and the entire in-pipe traveling device rotates around the pipeline axis. This allows the in-pipe traveling device to roll around the pipeline axis in the out-of-plane bent pipeline. Therefore, it is possible to provide an in-pipe traveling device capable of traveling in an out-of-plane bent pipeline without performing special operations or investigating the geometric information of the pipeline in advance. In addition, for example, by controlling the rotation axes of the first and second spherical wheels to rotate around the pipe axis relative to the link of the in-pipe traveling device, the in-pipe traveling device can be rolled around the pipe axis on the spot without moving to one side or the other. This makes it possible to optimally adjust the angle of the in-pipe traveling device around the pipe axis before the in-pipe traveling device enters a curved pipe, for example. This makes it easier to travel inside the pipe. Furthermore, since there are only two links, the in-pipe traveling device can be made smaller and lighter than in a case where three or more links are provided.

[0008] <2> An in-pipe traveling device according to a second aspect of the present invention is the in-pipe traveling device according to the first aspect, characterized in that the active joint portion is capable of torque control.

[0009] Here, there is a demand for an in-pipe traveling device that can be adapted to pipelines of a variety of inner diameters. At this time, it is necessary to ensure that the force with which the wheels are pressed against the inner wall surface of the pipeline is sufficient, regardless of the inner diameter of the pipeline. In other words, for example, if the force with which the wheels are pressed against the inner wall surface of the pipeline is small, the frictional force required for the in-pipe traveling device to travel through the pipeline is not sufficient, and the in-pipe traveling device cannot travel through the pipeline. According to the second aspect, the active joint unit capable of actively changing the angle between the first link and the second link is capable of torque control. This allows the active joint unit to change the angle between the first link and the second link to control the torque when the wheel is brought into contact with the inner wall surface of the pipeline, thereby making the force pressing the wheel against the inner wall surface of the pipeline sufficient regardless of the inner diameter of the pipeline. Therefore, for example, when the inner diameter of the pipeline is large, it is possible to prevent the in-pipe traveling device from being unable to travel through the pipeline by making the frictional force between the wheel and the inner wall surface of the pipeline sufficient.

[0010] <3> An in-pipe traveling device according to a third aspect of the present invention is the in-pipe traveling device according to the first or second aspect, characterized in that a low-friction geared motor is used for the active joint portion.

[0011] According to the third aspect, a low-friction geared motor is used for the active joint. This allows the active joint to relax when the power supply to the intra-pipe traveling device is cut off. Therefore, when the intra-pipe traveling device stops inside the pipe, it is easy to retrieve the intra-pipe traveling device from the pipe.

[0012] <4> An in-pipe running device according to aspect 4 of the present invention is an in-pipe running device according to any one of aspects 1 to 3, further comprising an encoder for detecting angles of the first spherical wheel and the second spherical wheel around the pipe axis.

[0013] According to aspect 4, the vehicle further includes an encoder for detecting the angles of the first spherical wheel and the second spherical wheel about the tube axis, which makes it easier to control the angles of the first spherical wheel and the second spherical wheel.

[0014] <5> An in-pipe running device according to aspect 5 of the present invention is an in-pipe running device according to any one of aspects 1 to 4, further comprising an operating unit capable of operating the rotational speed of the wheels, the angles of the first spherical wheel and the second spherical wheel about the pipe axis, and the torque of the active joint unit.

[0015] According to aspect 5, the device further includes an operating unit capable of operating the rotation speed of the wheels, the angles of the first and second spherical wheels about the pipe axis, and the torque of the active joint unit, thereby making it easier to operate the in-pipe traveling device.

[0016] <6> A control method for an in-pipe running device according to aspect 6 of the present invention is a control method for an in-pipe running device according to any one of aspects 1 to 5, characterized in that when entering a bent portion of the pipeline, each of the first spherical wheel and the second spherical wheel is controlled so as not to rotate around the pipeline axis relative to the first link and the second link.

[0017] According to the sixth aspect, when the in-pipe traveling device enters a bent portion of the pipeline, the first and second spherical wheels are controlled not to rotate around the pipeline axis relative to the first and second links. As a result, for example, when the in-pipe traveling device enters a pipeline with an in-plane bend from a pipeline with an out-of-plane bend and receives a force in a direction of rotation around the pipeline axis by contacting the inner wall surface of the pipeline with the first spherical wheel, the entire in-pipe traveling device rotates around the pipeline axis without a part of the in-pipe traveling device, such as only the first spherical wheel, rotating around the pipeline axis. This allows the in-pipe traveling device to roll around the pipeline axis in the pipeline with an out-of-plane bend. Therefore, it is possible to provide an in-pipe traveling device capable of traveling in a pipeline with an out-of-plane bend without performing special operations or investigating the geometric information of the pipeline in advance. In addition, since the operator does not need to perform fine operations while traveling through a pipeline with out-of-plane bends, operation of the in-pipe traveling device can be made easier.

[0018] <7> A method for controlling an in-pipe traveling device according to a seventh aspect of the present invention is characterized in that, in the method for controlling an in-pipe traveling device according to the sixth aspect, the torque of the active joint portion is controlled to be constant.

[0019] According to the seventh aspect, the torque of the active joint is controlled to be constant. This makes it possible to make the force pressing the wheel against the inner wall surface of the pipeline sufficient regardless of the inner diameter of the pipeline when the angle between the first link and the second link is changed to bring the wheel into contact with the inner wall surface of the pipeline. Therefore, for example, when the inner diameter of the pipeline is large, it is possible to prevent the in-pipe traveling device from being unable to travel through the pipeline by making the friction force between the wheel and the inner wall surface of the pipeline sufficient. Furthermore, even if the inner diameter of the pipeline changes while the vehicle is traveling through the pipeline, the force pressing the wheels against the inner wall surface of the pipeline can be prevented from changing.

[0020] <8> A control program for an in-pipe traveling device according to aspect 8 of the present invention is characterized in that it causes a computer to function as a control means for operating an in-pipe traveling device according to any one of aspects 1 to 5.

[0021] According to the eighth aspect, the computer functions as a control means for operating the in-pipe traveling device. This allows the in-pipe traveling device to travel through the pipeline while being operated as needed. Alternatively, the status of the in-pipe traveling device traveling through the pipeline can be grasped as needed. Effect of the Invention

[0022] According to the present invention, it is possible to provide an in-pipe traveling device capable of traveling through a pipeline with an out-of-plane bend, a control method for an in-pipe traveling device, and a control program for an in-pipe traveling device. [Brief description of the drawings]

[0023] [Figure 1] FIG. [Diagram 2] 4 is an enlarged view of the periphery of a first spherical wheel provided on the intra-pipe traveling device. FIG. [Diagram 3] 1 is a diagram showing a state in which an in-pipe traveling device is positioned inside a pipeline with a relatively small diameter. FIG. [Figure 4] 13 is a diagram showing a state in which the in-pipe traveling device is located inside a pipeline with a relatively large diameter. FIG. [Diagram 5]13 is an operation screen of an operation unit provided on the in-pipe traveling device. [Figure 6] FIG. 1 is a first diagram showing an in-pipe traveling device traveling through an out-of-plane bent pipe. [Figure 7] FIG. 2 is a second diagram showing the in-pipe traveling device traveling through an out-of-plane bent pipe. [Figure 8] FIG. 3 is a third diagram showing the in-pipe traveling device traveling through a pipe with an out-of-plane bend. [Figure 9] FIG. 4 is a fourth diagram showing the in-pipe traveling device traveling through a pipe with an out-of-plane bend. [Figure 10] FIG. 5 is a diagram showing the in-pipe traveling device traveling through a pipe with an out-of-plane bend. [Figure 11] FIG. 6 is a diagram showing the in-pipe traveling device traveling through a pipe with an out-of-plane bend. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an in-pipe traveling device according to an embodiment of the present invention will be described with reference to the drawings. The in-pipe traveling device travels inside a pipeline, such as a gas pipe. Thus, the in-pipe traveling device is used to inspect the state inside the pipeline. FIG. 1 is a perspective view of an in-pipe traveling device. FIG. 2 is an enlarged view of the periphery of a first spherical wheel provided on the intra-pipe traveling device. FIG. 3 is a diagram showing a state in which the in-pipe traveling device is positioned inside a pipeline with a relatively small diameter. FIG. 4 is a diagram showing a state in which the in-pipe traveling device is located inside a pipeline with a relatively large diameter. FIG. 5 shows an operation screen of the operation unit provided on the in-pipe traveling device.

[0025] As shown in FIGS. 1 and 2, the in-pipe traveling device 100 includes a first link 10, a second link 20, an imaging means 30, wheels 40, an encoder 50, an active joint unit 60, and an operation unit . In the following description, the side on which the in-pipe traveling device 100 advances will be referred to as one side, and the side on which it retreats will be referred to as the other side. Also, the central axis of the pipe P along which the in-pipe traveling device 100 travels will be referred to as the pipe axis Ps.

[0026] The first link 10 is provided on one side of the in-pipe traveling device 100. A first spherical wheel 41, which will be described later, is connected to an end of the first link 10 on one side. The other end of the first link 10 is connected to the second link 20 via an active joint 60 so as to be able to swing. The first link 10 has, for example, a box-like shape. In addition, a rotation axis JS about which the first link 10 swings relative to the second link 20 is located at the other end of the first link 10. Therefore, the other end of the first link 10 has a shape that does not interfere with the second link 20 when the first link 10 swings relative to the second link 20. Components such as a processing device and a motor (not shown) may be housed inside the box-shaped first link 10. The processing device is, for example, a CPU (Central Processing Unit) for controlling the in-pipe traveling device 100. The motor is, for example, a motor for driving the first spherical wheel 41, a servo motor for driving the active joint unit 60, etc. Additionally, an imaging means 30 may be attached to the first link 10.

[0027] The second link 20 is provided on the other side of the in-pipe traveling device 100. A second spherical wheel 42, which will be described later, is connected to an end portion on the other side of the second link 20. One end portion of the second link 20 is connected to the first link 10 via an active joint 60 so as to be able to swing. The second link 20 has, for example, a box-like shape. Furthermore, a rotation axis JS when the second link 20 swings relative to the first link 10 is located at one end of the second link 20. Therefore, the one end of the second link 20 is shaped not to interfere with the first link 10 when the second link 20 swings relative to the first link 10. The box-shaped second link 20 may house components such as a processing device and a motor (not shown) inside. The processing device is, for example, a CPU (Central Processing Unit) for controlling the in-pipe traveling device 100. The motor is, for example, a motor for driving the second spherical wheel 42, a servo motor for driving the active joint unit 60, etc. Additionally, an imaging means 30 may be attached to the second link 20. Furthermore, various cables C for supplying electricity to the in-pipe traveling device 100 or for transmitting control information for the in-pipe traveling device 100 may be connected to the second link 20 as shown in FIG.

[0028] The imaging means 30 is a known camera. The imaging means 30 images the inside of the pipeline P when the in-pipe traveling device 100 travels inside the pipeline P. The images or videos captured by the imaging means 30 are used as follows. That is, the image or video allows an operator to grasp the state of the inner wall surface S of the pipeline P. The image or video also allows an operator to grasp that the in-pipe traveling device 100 has reached a bent portion of the pipeline P, and the position and posture of the in-pipe traveling device 100 relative to the bent portion.

[0029] It is preferable that the imaging means 30 is capable of capturing images of both one side and the other side of the in-pipe traveling device 100. That is, in this embodiment, the imaging means 30 is provided on each of the first link 10 and the second link 20, for example, as shown in FIG.

[0030] The wheels 40 rotate so as to enable the in-pipe traveling device 100 to move to one side and the other side. Alternatively, the wheels 40 rotate so as to roll the in-pipe traveling device 100 about the pipe axis Ps. The wheels 40 include a first spherical wheel 41 , a second spherical wheel 42 , and a central wheel 43 .

[0031] The first spherical wheel 41 is provided at one end of the first link 10. The first spherical wheel 41 is formed by arranging a pair of hemispherical wheels 40 to face each other. The first spherical wheel 41 has a rotation axis 41s. The rotation axis 41s connects the centers of the pair of hemispherical wheels 40. As shown in FIG. 2, the first spherical wheel 41 can rotate around the rotation axis 41s by a motor 41m provided inside the first spherical wheel 41. That is, the first spherical wheel 41 having the above-mentioned configuration rotates around the rotation axis 41s, thereby making it possible to move the in-pipe traveling device 100 to one side and the other side.

[0032] Furthermore, the angle of the rotation axis 41s of the first spherical wheel 41 around the tube axis Ps can be controlled by the first encoder 51 described later. Note that being controllable means that the angle of the rotation axis 41s of the first spherical wheel 41 around the tube axis Ps can be actively changed by instructions from an operator or by program control. By rotating the rotation axis 41s of the first spherical wheel 41 around the tube axis Ps through the above-mentioned control, the in-pipe traveling device 100 can be made to roll around the tube axis Ps.

[0033] The second spherical wheel 42 is provided at the end of the other side of the second link 20. The second spherical wheel 42 is formed by arranging a pair of hemispherical wheels 40 to face each other. The second spherical wheel 42 has a rotation axis 42s. The rotation axis 42s connects the centers of the pair of hemispherical wheels 40 described above. The second spherical wheel 42, like the first spherical wheel 41, can rotate around the rotation axis 42s by a motor 42m provided inside the second spherical wheel 42, as shown in FIG. 1. That is, the second spherical wheel 42 having the above-mentioned configuration rotates around the rotation axis 42s, thereby making it possible to move the in-pipe traveling device 100 to one side and the other side.

[0034] The second spherical wheel 42 is capable of controlling the angle of the rotation axis 42s of the second spherical wheel 42 about the tube axis Ps by the second encoder 52 described later. Note that being controllable means that the angle of the rotation axis 42s of the second spherical wheel 42 about the tube axis Ps can be actively changed by instructions from an operator or by program control. By rotating the rotation axis 42s of the second spherical wheel 42 about the tube axis Ps through the above-mentioned control, the in-pipe traveling device 100 can be made to roll around the tube axis Ps.

[0035] The central wheel 43 is provided at the connection between the first link 10 and the second link 20. The central wheel 43 is provided so that a rotation axis 43s is aligned with a rotation axis JS of the active joint unit 60 described later. The central wheels 43 are provided in a pair so as to sandwich the connection between the first link 10 and the second link 20 from both sides of the rotation axis 43s of the central wheel 43. The central wheel 43 can rotate around the rotation axis 43s by a motor (not shown) provided inside the first link 10 or the second link 20, or both. This allows the in-pipe traveling device 100 to move to one side and the other side.

[0036] Furthermore, the central wheel 43 has the following configuration so as to be passively movable along the rotation axis 43s of the central wheel 43. That is, the central wheel 43 has a main body portion 43a and a roller 43b. The main body 43a is a disk-shaped member that rotates around a rotation axis 43s of the central wheel 43. The central wheel 43 enables the in-pipe traveling device 100 to move to one side and the other side by the rotation of the main body 43a. A plurality of rollers 43b are provided along the outer periphery of the main body 43a. The rotation axis of the rollers 43b is aligned along the tangent direction of the outer periphery of the main body 43a. The rollers 43b are passively rotatable when subjected to an external force. With the above configurations, for example, when the central wheel 43 receives a force from a direction along the rotation axis 43s of the central wheel 43 in a state where the central wheel 43 is in contact with a floor surface or the like, the central wheel 43 moves in a direction along the rotation axis 43s. As a result, when the in-pipe traveling device 100 is inside the pipeline P, the central wheel 43 can passively move by an external force so as to slide circumferentially on the inner wall surface S of the pipeline P. As the central wheel 43 having the above-mentioned configuration, for example, an Omniwheel (registered trademark) is preferably used.

[0037] The encoder 50 detects the angles of the first spherical wheel 41 and the second spherical wheel 42 about the tube axis Ps. The encoder 50 also rotates the first spherical wheel 41 and the second spherical wheel 42 about the tube axis Ps relative to the first link 10 and the second link 20, respectively. The encoder 50 includes a first encoder 51 and a second encoder 52 .

[0038] The first encoder 51 detects the angle of the first spherical wheel 41 around the tube axis Ps. The first encoder 51 also rotates the first spherical wheel 41 around the tube axis Ps relative to the first link 10. The first encoder 51 is provided between the first spherical wheel 41 and the first link 10, as shown in Figs. 1, 3 and 4. The first encoder 51 is preferably provided with, for example, a magnetic encoder. The second encoder 52 detects the angle of the second spherical wheel 42 about the tube axis Ps. In addition, the second encoder 52 rotates the second spherical wheel 42 about the tube axis Ps relative to the second link 20. The second encoder 52 is provided between the second spherical wheel 42 and the second link 20, as shown in Figs. 1, 3, and 4. The second encoder 52 is preferably provided with, for example, a magnetic encoder.

[0039] The active joint unit 60 swingably connects the first link 10 and the second link 20. The active joint unit 60 can actively change the angle between the first link 10 and the second link 20 (the angle between the first link 10 and the second link 20). In other words, the active joint unit 60 is a motor, and is arranged so that a rotation axis 60s coincides with the rotation axis JS when the first link 10 and the second link 20 swing relative to each other.

[0040] When the in-pipe traveling device 100 travels through the pipeline P, as shown in Fig. 3 or 4, the active joint unit 60 adjusts the angle between the first link 10 and the second link 20, and each of the wheels 40 contacts the inner wall surface S of the pipeline P. That is, the first spherical wheel 41 and the second spherical wheel 42 contact a first inner wall surface S1 of the inner wall surface S of the pipeline P. Also, the central wheel 43 contacts a second inner wall surface S2 of the inner wall surface S of the pipeline P that faces the first inner wall surface S1 in the radial direction, with the pipe axis Ps of the pipeline P therebetween.

[0041] At this time, in order to prevent the wheels 40 from spinning due to insufficient friction between the wheels 40 and the inner wall surface S of the pipeline P, the wheels 40 need to be pressed against the inner wall surface S of the pipeline P to an extent that ensures the friction required for the intra-pipe traveling device 100 to travel through the pipeline P. The force pressing the wheels 40 against the inner wall surface S of the pipeline P is generated by the torque of the active joint unit 60 when changing the angle between the first link 10 and the second link 20.

[0042] Therefore, in this embodiment, the motor used in the active joint unit 60 is capable of torque control. Furthermore, when the intra-pipe traveling device 100 is located inside the pipeline P, the active joint unit 60 is controlled so that the torque is constant. As a result, for example, as shown in Figs. 3 and 4, even if the inner diameter of the pipeline P changes, the force pressing the wheels 40 against the inner wall surface S of the pipeline P can be kept constant. Therefore, regardless of the inner diameter of the pipeline P, a frictional force required for the intra-pipe traveling device 100 to travel through the pipeline P can be secured between the wheels 40 and the inner wall surface S of the pipeline P.

[0043] In this embodiment, for example, a low-friction geared motor is used for the active joint unit 60. In this embodiment, a geared motor whose input shaft starts to rotate with an accelerated starting torque (reverse starting torque) of 1 Nm or less is called a low-friction geared motor. By using a low-friction geared motor for the active joint unit 60, the active joint unit 60 loses force when the power of the in-pipe traveling device 100 is turned off. Therefore, when the in-pipe traveling device 100 stops inside the pipeline P, it is possible to easily retrieve the in-pipe traveling device 100 from the pipeline P.

[0044] The operation unit 70 enables operation of the rotation speed of the wheel 40, the angles of the first spherical wheel 41 and the second spherical wheel 42 about the tube axis Ps, and the torque of the active joint unit 60. The operation unit 70 includes an operation screen 71 and a display control device 72 that displays the operation screen 71. The operation screen 71 is a so-called GUI (Graphical User Interface) for an operator to input instructions to the in-pipe traveling device 100. The operation screen 71 includes, for example, as shown in Fig. 5, a robot state display section 71a, a camera image display section 71b, a motor state display section 71c, and an instruction input section 71d.

[0045] The robot state display section 71a is an area showing the state of the in-pipe traveling device 100. That is, for example, the first link 10 and the second link 20 are each represented by a straight line, and the wheels 40 are each represented by a circle. Then, the robot state display section 71a displays the angle between the respective straight lines corresponding to the first link 10 and the second link 20 according to the actual angle between the first link 10 and the second link 20. This allows the worker to visually grasp the angle between the first link 10 and the second link 20.

[0046] The camera image display section 71b is an area that constantly displays images captured by the imaging means 30 provided in the in-pipe traveling device 100. This allows the operator to grasp the state inside the pipe and the position and posture of the in-pipe traveling device 100 relative to the bent portion of the pipe P. As described above, in this embodiment, the imaging means 30 is provided on each of the first link 10 and the second link 20 so as to be able to capture images of one side and the other side. For this reason, it is preferable that the camera image display section 71b has an area for displaying an image captured by the imaging means 30 provided on the first link 10, and an area for displaying an image captured by the imaging means 30 provided on the second link 20.

[0047] The motor state display section 71c is an area that displays the state (e.g., current and speed) of each motor included in the in-pipe traveling device 100. For example, a graph with time (seconds) on the horizontal axis and rotation speed (rpm) on the vertical axis is displayed in the motor state display section 71c. The graph is provided for each of the motors included in the in-pipe traveling device 100. That is, as shown in FIG. 5, in this embodiment, graphs corresponding to the following six motors are displayed: A motor that rotates the first spherical wheel 41 around the rotation axis 41s. A motor that rotates the second spherical wheel 42 around a rotation axis 42s. A motor that rotates the central wheel 43 around the rotation axis 43s. A motor (first encoder 51) that rotates the rotation shaft 41s of the first spherical wheel 41 around the tube axis Ps. A motor (first encoder 51) that rotates the rotation shaft 42s of the second spherical wheel 42 around the tube axis Ps. A motor (active joint 60) that swings the first link 10 and the second link 20.

[0048] The instruction input unit 71d is provided for an operator to input instructions to the in-pipe traveling device 100. For example, the instruction input unit 71d includes a plurality of icons displayed on a screen. The operator inputs instructions to the in-pipe traveling device 100 by clicking or tapping the plurality of icons. That is, for example, as shown in FIG. 5, the following icons are available: The first icon I1 controls the current and speed of the motor that rotates the first spherical wheel 41 around the rotation axis 41s. A second icon I2 changes the current and speed of the motor that rotates the second spherical wheel 42 around the rotation axis 42s. The third icon I3 changes the angle of the rotation axis 41s of the first spherical wheel 41 about the tube axis Ps relative to the first link 10. The fourth icon I4 changes the angle of the rotation axis 42s of the second spherical wheel 42 about the tube axis Ps relative to the second link 20. A fifth icon I5 changes the current and speed of the motor that rotates the central wheel 43 around the rotation axis 43s. A sixth icon I6 changes the current or torque of the active joint 60. The seventh icon I7 intuitively changes the posture and speed of the in-pipe traveling device 100. In other words, the seventh icon I7 gives operational instructions such as "increase the speed of the in-pipe traveling device 100" and "increase or decrease the angle between the first link and the second link" without manipulating the current or speed of each motor. An eighth icon I8 instructs playback, stopping, and saving of the image displayed in the camera image display portion 71b. An operator operates the in-pipe traveling device 100 using the operation screen 71 having the above-mentioned components.

[0049] The display control device 72 is, for example, a control device equipped with a display unit that displays the operation screen 71. For example, a known PC or a tablet PC is suitably used as the display control device 72. Note that in addition to displaying the operation screen 71, the display control device 72 may also function to process various information required to control the in-pipe traveling device 100 and to execute a program that operates the in-pipe traveling device 100. In this embodiment, each component of the in-pipe traveling device 100, except for the operation unit 70, is wired to the operation unit 70 by a cable C. For example, a controller area network (CAN) is preferably used for the wired connection. Alternatively, for example, a universal serial bus (USB) or a local area network (LAN) may be used. The display control device 72 includes a processor such as a central processing unit (CPU) and a memory connected by a bus, and executes a preconfigured control program to ensure the respective functions. The display control device 72 may be realized using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA). The program for controlling the display control device 72 may be recorded on a computer-readable recording medium.

[0050] The computer-readable recording medium is, for example, a portable medium such as a flexible disk, an optical magnetic disk, a ROM, a CD-ROM, or a USB flash memory, or a storage device such as a hard disk built into a computer system. The program may be transmitted via a telecommunication line.

[0051] (Method of controlling in-pipe traveling device 100) Next, a control method for the in-pipe traveling device 100 according to this embodiment will be described. That is, when entering a bent portion of the pipeline P, the first spherical wheel 41 and the second spherical wheel 42 are controlled so as not to rotate about the pipeline axis Ps relative to the first link 10 and the second link 20, respectively. In addition, the torque of the active joint unit 60 is controlled to be constant. The above control method allows the in-pipe traveling device 100 according to this embodiment to travel through the pipeline P with an out-of-plane bend.

[0052] Hereinafter, a process in which the in-pipe traveling device 100 travels through the out-of-plane bent pipe P using the above control method will be described with reference to Figs. FIG. 6 is a first diagram showing the in-pipe traveling device 100 traveling through a pipe P with an out-of-plane bend. FIG. 7 is a second diagram showing the in-pipe traveling device 100 traveling through the pipe P with an out-of-plane bend. FIG. 8 is a third diagram showing the in-pipe traveling device 100 traveling through the out-of-plane bent pipe P. FIG. 9 is a fourth diagram showing the in-pipe traveling device 100 traveling through a pipe P with an out-of-plane bend. FIG. 10 is a fifth diagram showing the in-pipe traveling device 100 traveling through a pipe P with an out-of-plane bend. FIG. 11 is a sixth diagram showing the in-pipe traveling device 100 traveling through a pipe P with an out-of-plane bend.

[0053] In this embodiment, an out-of-plane bent pipeline P refers to a pipeline P in which multiple elbows E are provided in succession, and the planes containing the curved pipe axis Ps of the multiple elbows E are different from each other. In the following description, the elbow E into which the in-pipe traveling device 100 first enters as shown in Fig. 6 is referred to as the in-plane bent pipe P. The elbow E into which the in-pipe traveling device 100 enters next after the in-plane bent pipe P is referred to as the out-of-plane bent pipe P.

[0054] First, as shown in Fig. 6, before the in-pipe traveling device 100 enters the in-plane bent pipeline P, the posture of the in-pipe traveling device 100 is adjusted to match the in-plane bent pipeline P. The posture of the in-pipe traveling device 100 is adjusted by rolling the in-pipe traveling device 100 around the pipe axis Ps. In the state shown in Figure 6, when the in-pipe traveling device 100 enters the in-plane bent pipeline P, both of the pair of hemispherical wheels 40 of the first spherical wheel 41 are adjusted to a position in contact with the inner wall surface S of the in-plane bent pipeline P. Thereafter, the first spherical wheel 41 and the second spherical wheel 42 are controlled so as not to rotate around the pipe axis Ps relative to the first link 10 and the second link 20. In addition, by controlling the torque of the active joint unit 60, each of the wheels 40 is pressed against the inner wall surface S of the pipeline P with a force sufficient for the in-pipe traveling device 100 to travel through the pipeline P.

[0055] When the wheel 40 is rotated from the state shown in Fig. 6, the in-pipe traveling device 100 moves toward the in-plane bent pipeline P, as shown in Fig. 7. At this time, even if the positional relationship of the wheel 40 with respect to the inner wall surface S of the pipeline P changes, the torque of the active joint unit 60 is controlled to be constant, so that the force with which the wheel 40 is pressed against the inner wall surface S of the pipeline P is kept constant.

[0056] When the in-pipe traveling device 100 moves further from the state shown in Fig. 7, the first spherical wheel 41 enters the out-of-plane bent pipeline P, as shown in Fig. 8. Then, only one of the pair of hemispherical wheels 40 of the first spherical wheel 41 is in contact with the inner wall surface S of the pipeline P. As the entry into the pipeline P progresses, the state of contact with the inner wall surface S expands to include the side surface of one of the wheels 40, and the first spherical wheel 41 receives a force in a direction rotating around the pipeline axis Ps. At this time, as described above, by controlling each of the first spherical wheel 41 and the second spherical wheel 42 so as not to rotate about the pipe axis Ps relative to the first link 10 and the second link 20, a force in the direction of rotation of the first spherical wheel 41 about the pipe axis Ps is transmitted to the entire intra-pipe traveling device 100. This force causes the central wheel 43 having the above-mentioned configuration to move inside the pipe P so as to slide circumferentially on the inner wall surface S of the pipe P by the rotation of the rollers 43b.

[0057] 9 and 10, the entire in-pipe traveling device 100 rotates about the pipe axis Ps, without a part of the in-pipe traveling device 100, such as only the first spherical wheel 41, rotating about the pipe axis Ps. This allows the in-pipe traveling device 100 to perform a roll rotation about the pipe axis Ps in a pipe P that is bent out of plane. As the in-pipe traveling device 100 continues to move in this state, the in-pipe traveling device 100 passes through the out-of-plane bent pipe P, as shown in FIG. In this manner, the in-pipe traveling device 100 according to this embodiment is capable of traveling through a pipe P that has an out-of-plane bend.

[0058] (Control program for the in-pipe traveling device 100) Next, a description will be given of a control program for the in-pipe traveling device 100 according to this embodiment. That is, the program causes a computer to function as a control means for operating the in-pipe traveling device 100 according to this embodiment. The control program according to this embodiment is executed, for example, by a control device housed in the first link 10 or the second link 20 of the in-pipe traveling device 100. Alternatively, as described above, the control program according to this embodiment may be executed by the display control device 72 that displays the operation screen 71 of the operation unit 70.

[0059] As described above, according to the in-pipe traveling device 100 of this embodiment, the first spherical wheel 41 can control the angle around the pipe axis Ps with respect to the rotation axis 41s of the first spherical wheel 41, and the second spherical wheel 42 can control the angle around the pipe axis Ps with respect to the rotation axis 42s of the second spherical wheel 42. The central wheel 43 can passively move along the rotation axis 43s of the central wheel 43. That is, the central wheel 43 can passively move by an external force so as to slide in the circumferential direction on the inner wall surface S of the pipe P, in addition to rotating so as to move the in-pipe traveling device 100 to one side and the other side. With these, for example, when the in-pipe traveling device 100 enters the in-plane bent pipe P into the out-of-plane bent pipe P, and the first spherical wheel 41 comes into contact with the inner wall surface S of the pipe P and receives a force in a direction to rotate around the pipe axis Ps, it can be controlled as follows. That is, by controlling the rotation axes 41s, 42s of the first spherical wheel 41 and the second spherical wheel 42 so that they do not rotate around the pipe axis Ps relative to the link of the in-pipe traveling device 100 (controlling the rotation axes 41s, 42s in a direction intersecting the pipe axis Ps), for example, a part of the in-pipe traveling device 100, such as only the first spherical wheel 41, does not rotate around the pipe axis Ps, and the entire in-pipe traveling device 100 rotates around the pipe axis Ps. As a result, the in-pipe traveling device 100 can be roll-rotated around the pipe axis Ps in the out-of-plane bent pipe P. Therefore, without any special operations or the like, and without investigating the geometric information of the pipeline P in advance, the in-pipe traveling device 100 can be made to be capable of traveling through the pipeline P with an out-of-plane bend. Also, for example, by controlling the rotation axes 41s, 42s of the first spherical wheel 41 and the second spherical wheel 42 to rotate about the pipe axis Ps relative to the link of the in-pipe traveling device 100, the in-pipe traveling device 100 can be rolled around the pipe axis Ps on the spot without moving to one side or the other. This makes it possible to optimally adjust the angle of the in-pipe traveling device 100 about the pipe axis Ps before the in-pipe traveling device 100 enters the curved pipe P, for example. This makes it easier to travel inside the pipe P. Furthermore, since there are only two links, the in-pipe traveling device 100 can be made smaller and lighter in weight than in a case where three or more links are provided.

[0060] Here, there is a demand for the in-pipe traveling device 100 to be adaptable to pipelines P with a plurality of inner diameters. In this case, it is necessary to ensure that the force with which the wheels 40 are pressed against the inner wall surface S of the pipeline P is sufficient, regardless of the inner diameter of the pipeline P. In other words, for example, if the force with which the wheels 40 are pressed against the inner wall surface S of the pipeline P is small, the frictional force required for the in-pipe traveling device 100 to travel through the pipeline P is not sufficient, and the in-pipe traveling device 100 will not be able to travel through the pipeline P. Therefore, the active joint unit 60 capable of actively changing the angle between the first link 10 and the second link 20 is capable of torque control. Thus, by controlling the torque when the active joint unit 60 changes the angle between the first link 10 and the second link 20 to bring the wheel 40 into contact with the inner wall surface S of the pipeline P, the force pressing the wheel 40 against the inner wall surface S of the pipeline P can be made sufficient regardless of the inner diameter of the pipeline P. Thus, for example, when the inner diameter of the pipeline P is large, by making the frictional force between the wheel 40 and the inner wall surface S of the pipeline P sufficient, it is possible to prevent the in-pipe traveling device 100 from being unable to travel through the pipeline P.

[0061] In addition, a low-friction geared motor is used for the active joint unit 60. As a result, when the power supply of the intra-pipe traveling device 100 is cut off, the active joint unit 60 is relaxed. Therefore, when the intra-pipe traveling device 100 stops inside the pipeline P, the intra-pipe traveling device 100 can be easily retrieved from the pipeline P.

[0062] The vehicle further includes an encoder 50 that detects the angles of the first spherical wheel 41 and the second spherical wheel 42 about the tube axis Ps. This makes it easier to control the angles of the first spherical wheel 41 and the second spherical wheel 42.

[0063] The device further includes an operation unit 70 capable of operating the rotation speed of the wheels 40, the angles of the first spherical wheel 41 and the second spherical wheel 42 about the pipe axis Ps, and the torque of the active joint unit 60. This makes it easier to operate the in-pipe traveling device 100.

[0064] According to the control method for the in-pipe traveling device 100 of this embodiment, when the in-pipe traveling device 100 enters a bent portion of the pipe P, the first spherical wheel 41 and the second spherical wheel 42 are controlled so as not to rotate around the pipe axis Ps relative to the first link 10 and the second link 20. As a result, for example, when the in-pipe traveling device 100 enters the pipe P with an out-of-plane bend from the pipe P with an in-plane bend and receives a force in a direction of rotation around the pipe axis Ps by contacting the inner wall surface S of the pipe P, the entire in-pipe traveling device 100 rotates around the pipe axis Ps without a part of the in-pipe traveling device 100, such as only the first spherical wheel 41, rotating around the pipe axis Ps. As a result, the in-pipe traveling device 100 can be rolled around the pipe axis Ps in the pipe P with an out-of-plane bend. Therefore, without any special operations or the like, and without investigating the geometric information of the pipeline P in advance, the in-pipe traveling device 100 can be made to be capable of traveling through the pipeline P with an out-of-plane bend. In addition, since the operator does not need to perform fine operations while traveling through the out-of-plane bent pipeline P, the operation of the in-pipe traveling device 100 can be made easier.

[0065] In addition, the torque of the active joint unit 60 is controlled to be constant. This makes it possible to make the force pressing the wheel 40 against the inner wall surface S of the pipeline P sufficient regardless of the inner diameter of the pipeline P when the angle between the first link 10 and the second link 20 is changed to bring the wheel 40 into contact with the inner wall surface S of the pipeline P. Therefore, for example, when the inner diameter of the pipeline P is large, by making the frictional force between the wheel 40 and the inner wall surface S of the pipeline P sufficient, it is possible to prevent the in-pipe traveling device 100 from becoming unable to travel through the pipeline P. Furthermore, even if the inner diameter of the pipeline P changes while the vehicle is traveling through the pipeline P, the force pressing the wheels 40 against the inner wall surface S of the pipeline P can be prevented from changing.

[0066] Furthermore, the control program for the in-pipe traveling device 100 according to this embodiment causes the computer to function as a control means for operating the in-pipe traveling device 100. This allows the in-pipe traveling device 100 to travel through the pipeline P while being operated as needed. Alternatively, the status of the in-pipe traveling device 100 traveling through the pipeline P can be grasped as needed.

[0067] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, although the imaging means 30 has been described as being capable of photographing one side and the other side, this is not limited thereto. That is, the direction perpendicular to the tube axis Ps may be photographed by changing the orientation of the lens of the imaging means 30 provided on each of the first link 10 and the second link 20. Alternatively, a camera capable of photographing in all directions may be used as the imaging means 30 and provided on only either the first link 10 or the second link 20, thereby enabling photographing in all directions by a single imaging means 30. Furthermore, for example, the angle of the first spherical wheel 41 about the pipe axis Ps relative to the first link 10 and the angle of the second spherical wheel 42 about the pipe axis Ps relative to the second link 20 may be changed from the angles in the above-described embodiment, and only one of the hemispherical wheels 40 of each of the spherical wheels 41, 42 may be brought into contact with the pipeline P, and the first spherical wheel 41 and the second spherical wheel 42 may be rotated about the rotation axes 41s, 42s, so that the intra-pipe running device 100 moves along the straight pipeline P while rotating in a spiral manner. Moreover, the in-pipe traveling device 100 and the control method thereof according to this embodiment may be used to travel through a so-called inverted pipe P. Furthermore, by sufficiently pressing the wheels 40 against the inner wall surface S of the pipeline P using the method according to this embodiment, the in-pipe traveling device 100 may be caused to travel inside the pipeline P extending in the vertical direction.

[0068] In addition, within the scope of the invention, the components in the above-described embodiments may be replaced with well-known components, and the above-described modified examples may be combined as appropriate. [Explanation of symbols]

[0069] 10 First link 20 Second Link 30 Imaging means 40 wheels 41 1st spherical wheel 41m motor 41s Rotating shaft 42 Second spherical wheel 42m motor 42s Rotating shaft 43 Central Wheel 43a Main body 43b Lola 43s Rotating shaft 50 Encoder 51 First Encoder 52 Second Encoder 60 Active joint 60s Rotation Axis 70 Operation section 71 Operation screen 71a Robot status display section 71b Camera image display section 71c Motor status display unit 71d Instruction input section 72 Display control device 100 In-pipe traveling device C Cable I1 First Icon I2 2nd Icon I3 3rd icon I4 4th Icon I5 5th Icon I6 6th Icon I7 7th Icon I8 8th Icon JS Rotation Axis P conduit Ps tube shaft S Inner wall surface S1 First inner wall S2 2nd inner wall surface

Claims

1. An in-pipe traveling device that travels inside a pipeline, A first link provided on one side of the in-pipe traveling device; A second link provided on the other side of the intrapipe traveling device and connected to the first link; an active joint portion that swingably connects the first link and the second link and that can actively change an angle between the first link and the second link; A wheel that rotates so as to enable the in-pipe traveling device to move to the one side and the other side; Equipped with The wheel is a first spherical wheel provided at an end of the first link on the one side and rotatable about a rotation axis; a second spherical wheel provided at the other end of the second link and rotatable about a rotation axis; a central wheel having a rotation axis aligned with the rotation axis of the active joint; Including, In a state in which the active joint adjusts the angle between the active joint and the first link and the second link, the first spherical wheel and the second spherical wheel are in contact with a first inner wall surface of the inner wall surface of the pipeline, and the central wheel is in contact with a second inner wall surface of the inner wall surface of the pipeline that faces the first inner wall surface in a radial direction with a pipe axis of the pipeline therebetween; the first spherical wheel is capable of controlling an angle around a pipe axis of the pipeline with respect to a rotation axis of the first spherical wheel; the second spherical wheel is capable of controlling an angle around a pipe axis of the pipeline with respect to a rotation axis of the second spherical wheel; the central wheel is passively movable along its axis of rotation; An in-pipe traveling device characterized by:

2. The active joint is capable of torque control.

2. The in-pipe traveling device according to claim 1 .

3. A low-friction geared motor is used for the active joint.

2. The in-pipe traveling device according to claim 1 .

4. An encoder for detecting an angle of the first spherical wheel and the second spherical wheel around the tube axis is further provided.

2. The in-pipe traveling device according to claim 1 .

5. An operation unit capable of operating the rotation speed of the wheels, the angles of the first spherical wheel and the second spherical wheel about the tube axis, and the torque of the active joint unit.

2. The in-pipe traveling device according to claim 1 .

6. A method for controlling an in-pipe traveling device according to claim 1, When entering a bent portion of the pipeline, the first spherical wheel and the second spherical wheel are controlled so as not to rotate about an axis of the pipeline relative to the first link and the second link, respectively. A method for controlling an in-pipe traveling device.

7. The torque of the active joint is controlled to be constant.

7. The method for controlling an in-pipe traveling device according to claim 6.

8. A computer is caused to function as a control means for operating the in-pipe traveling device according to any one of claims 1 to 5. Control program for the in-pipe traveling device.

Images