Crawling equipment and method for outer wall of pipeline with variable pipe diameter and variable pipe wall thickness

Abstract

The invention relates to pipeline outer wall crawling equipment and method for variable pipe diameters and variable pipe wall thicknesses in the field of automation engineering. According to the outer wall crawling method facing the variable pipe wall thickness, pipeline outer wall crawling equipment needs to be designed, the equipment is used for a crawler belt walking on the outer wall of a metal pipeline and a plurality of electromagnets which are installed in the crawler belt, are arranged in the same ring with the crawler belt and are connected in series, and the electromagnets have metal adsorption force under the power-on condition; and all the electromagnets on the contact positions of the crawler belt and the pipeline provide adsorption force to the pipeline. According to the outer wall crawling method, the pipe wall thickness of the pipeline in the advancing direction of the crawler belt is detected, so that the current conveyed to the electromagnet is adjusted, the adsorption force is adjusted, the crawling equipment can crawl on different pipelines, and the technical problem that in the prior art, crawling on the pipelines with different pipe wall thicknesses is difficult is solved; and the crawling equipment can crawl outside pipelines with different pipeline wall thicknesses.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automation engineering, in particular to a pipe outer wall crawling method for variable pipe wall thickness, a pipe outer wall crawling device for variable pipe wall thickness for sampling the pipe outer wall crawling method for variable pipe wall thickness, a pipe outer wall crawling method for variable pipe diameter, and a pipe outer wall crawling device for variable pipe diameter for sampling the pipe outer wall crawling method for variable pipe diameter. BACKGROUND

[0002] In recent years, the development of pipe outer wall crawling devices has provided technical support for automation engineering. However, due to the different thicknesses of the pipes, different adsorption forces are required. If the adsorption force used when the pipe wall thickness is low is too large, the pipe outer wall crawling device will stay on the pipe and cannot move forward. If the adsorption force used when the pipe wall thickness is high is too small, the pipe will not be adsorbed and will fall off. Different pipe wall thicknesses require different crawling devices, so only one crawling device cannot be used during work, increasing the difficulty of work. At the same time, when crawling the pipe, the size of the pipe diameter is not the same, and the crawling device will become loose or be blocked when crawling. When the pipe diameter becomes larger, the crawling device is blocked and cannot climb up. When the pipe diameter becomes smaller, the crawling device becomes loose, the friction between the crawling device and the pipe becomes smaller, and the crawling device cannot crawl. When the pipe diameter becomes smaller, the crawling device becomes loose and is easy to fall off, so the crawling performance of the crawling device is unstable. SUMMARY

[0003] (1) Technical problem to be solved

[0004] In order to solve the technical problem that the prior art cannot crawl on pipes with different pipe wall thicknesses, the present application discloses a pipe outer wall crawling method for variable pipe wall thickness and a crawling device using the control method.

[0005] (2) Technical solution

[0006] In a first aspect, the present application provides a pipe outer wall crawling method for variable pipe wall thickness, comprising the following steps:

[0007] A pipe outer wall crawling device is provided, comprising: a track belt for walking on the outer wall of a metal pipe, and a plurality of series-connected electromagnets arranged in the track belt and arranged in a ring with the track belt. The electromagnets have metal adsorption force under the condition of being powered on, so that all the electromagnets at the contact position of the track belt and the pipe provide adsorption force to the pipe;

[0008] Detect the pipe wall thickness t of the pipe in the advancing direction of the track belt;

[0009] Adjust the current I supplied to the electromagnets according to the pipe wall thickness t to adjust the adsorption force:

[0010]

[0011] In the formula, F Z The total adsorption force required for the pipe-side crawling device is given by g, where g0 is the air gap between the electrode surface and the pipe when they are in contact, and the surface of the electromagnet adsorbed on the pipe is the electrode surface. t l For track wall thickness, μ l μ r The relative magnetic permeability of the track material and the pipe material are respectively, Δg=|RR e |, R is the outer radius of the pipe, R e Let θ be the radius of curvature of the pole face, θ be the sum of the coverage angles of all electromagnets at the contact position, n be the number of all electromagnets at the contact position, A be the contact area between all electromagnets at the contact position and the pipe, μ0 be the permeability of free space, and N be the number of coil turns of each electromagnet.

[0012] As an improvement to the above scheme, F Z satisfy:

[0013] The crawling device remains stationary and does not slip on the outer wall of the pipe: μ s F Z ≥mg sinβ,

[0014] The crawling device climbs upwards on the outer wall of the pipe: F d >mg sinβ+μ k F z ,

[0015] The crawling device crawls downwards on the outer wall of the pipe: F d >μ k F z -mg sinβ,

[0016] In the formula, β is the angle between the pipe axis and the horizontal plane, and F d For the driving force of the crawling device, μ k Let μ be the coefficient of dynamic friction between the track and the outer wall of the pipe. s denoted as the static friction coefficient between the track and the outer wall of the pipe, and mg as the weight of the crawling equipment.

[0017] Secondly, the present invention also proposes a pipe wall crawling device for variable pipe wall thickness, the pipe wall crawling device comprising:

[0018] Tracks are used to move along the outer wall of metal pipes. Multiple electromagnets connected in series are installed inside the tracks and arranged in the same ring. When energized, the electromagnets have a metal attraction force, so that all the electromagnets at the contact position between the tracks and the pipes provide an attraction force to the pipes.

[0019] Pipe thickness gauge, used to detect the pipe wall thickness t in the direction of track travel;

[0020] The controller is used to adjust the current I supplied to the electromagnet according to the pipe wall thickness t using the above-mentioned crawling method on the outer wall of the pipe with an arbitrary orientation and variable pipe wall thickness, so as to adjust the adsorption force.

[0021] As an improvement to the above solution, the pipe external wall crawling device includes:

[0022] A crawling mechanism, including the track and a main structure mounted on the track for driving the track to move;

[0023] The crawling auxiliary mechanism is installed on the main structure at both ends around the pipe to assist the crawling mechanism in crawling around the pipe.

[0024] As an improvement to the above solution, the pipe outer wall crawling device includes:

[0025] Multiple crawling mechanisms are evenly arranged in a ring around the pipe. Each crawling mechanism includes the track and a main structure mounted on the track for driving the track to move. At this time, F Z The total suction force required for each crawling mechanism;

[0026] Multiple connecting mechanisms are provided, with one connecting structure installed between two adjacent crawling mechanisms to assist the multiple crawling mechanisms in crawling around the pipe.

[0027] As an improvement to the above scheme, the inner ring of the track has multiple protrusions, each of which houses an electromagnet.

[0028] As an improvement to the above solution, the inner ring of the track has multiple protrusions, each protrusion housing an electromagnet, and a spring fixed between each protrusion and the inner ring of the track. The spring is used to provide elastic force to the corresponding electromagnet when the corresponding electromagnet contacts the outer wall of the pipe.

[0029] As an improvement to the above solution, the crawling device also includes a main structure mounted on the tracks and used to drive the tracks to move; the main structure includes a drive mechanism, a pipe outer wall contact surface adjustment mechanism, and a track tension adjustment mechanism.

[0030] The drive mechanism includes a driving wheel, a driven wheel, a connecting rod linking the driving wheel and the driven wheel, and a motor driving the driving wheel. The pipe outer wall contact surface adjustment mechanism includes two hydraulic struts, two support rods, and two support wheels; one end of each of the two hydraulic struts and one end of each support rod are movably connected to the same side of the connecting rod, and the other ends of the two hydraulic struts are rotatably connected to the other ends of the two support rods. Two support wheels are mounted on the end faces of the two support rods away from the connecting rod. The track tension adjustment mechanism includes a second hydraulic strut, a second support rod, and a tensioning wheel; one end of each of the second hydraulic strut and one support rod are movably connected to the opposite side of the connecting rod, and the other end of the second hydraulic strut is rotatably connected to the other end of the support rod. A tensioning wheel is mounted on the end face of the support rod away from the connecting rod.

[0031] The drive wheel, driven wheel, two support wheels, and tension wheel together support the track. The two support wheels stabilize the contact area of ​​the track when it walks on the outer wall of the pipe. The tension wheel adjusts the friction between the track and each wheel. The drive wheel and driven wheel drive the track to move.

[0032] Furthermore, the pipe outer wall crawling device also includes a pipe diameter measuring instrument, used to detect the outer ring radius R of the pipe in the direction of the track's travel;

[0033] The controller is also used to adjust the extension degree of each hydraulic strut according to the outer ring radius R of the pipeline based on the fitted relationship curve. The fitted relationship curve is fitted according to the extension degree required for each support wheel to match different R values.

[0034] Thirdly, the present invention also proposes a method for crawling along the outer wall of a pipe with a variable diameter, which includes the following steps:

[0035] A pipe external wall crawling device is provided. The crawling device includes a track for walking on the external wall of a metal pipe and a main structure mounted on the track for driving the track. The main structure includes: a drive mechanism, a pipe external wall contact surface adjustment mechanism and a track tension adjustment mechanism located on opposite sides of a pipe external wall contact surface adjustment mechanism, and a pipe diameter measuring instrument for detecting the pipe outer ring radius R in the track's traveling direction. The drive mechanism includes a driving wheel, a driven wheel, a connecting rod that links the driving wheel and the driven wheel, and a motor that drives the driving wheel. The pipe external wall contact surface adjustment mechanism includes two hydraulic struts, two support rods, and two support wheels. One end of each of the two hydraulic struts and one end of each support rod are movably connected to the same connecting rod. On the side, the other ends of two hydraulic struts are rotatably connected to the other ends of two support rods. Two support wheels are respectively installed on the end faces of the two support rods away from the connecting rod. The track tension adjustment mechanism includes a hydraulic strut, a support rod, and a tension wheel. One end of the hydraulic strut and the support rod are movably connected to the opposite side of the connecting rod. The other end of the hydraulic strut is rotatably connected to the other end of the support rod. A tension wheel is installed on the end face of the support rod away from the connecting rod. The drive wheel, the driven wheel, the two support wheels, and the tension wheel together support the track. By driving the two support wheels, the contact area of ​​the track when it walks on the outer wall of the pipe is stabilized. The tension wheel adjusts the friction between the track and each wheel. The drive wheel and the driven wheel drive the track to move.

[0036] Detect the outer radius R of the pipe in the direction of track travel;

[0037] The extension and retraction of each hydraulic strut is adjusted according to the fitting relationship curve based on the outer ring radius R of the pipeline, so that the track can adapt to the variable diameter pipeline; the fitting relationship curve is fitted according to the extension and retraction of each support wheel to match different R values.

[0038] As an improvement to the above solution, the pipe external wall crawling device also includes multiple electromagnets connected in series and installed inside the track and arranged in the same ring as the track. When energized, the electromagnets have a metal attraction force, so that all the electromagnets at the contact position between the track and the pipe provide an attraction force to the pipe.

[0039] Pipeline wall crawling methods for variable diameter pipes also include:

[0040] Detect the wall thickness t of the pipe in the direction of track travel;

[0041] The current I supplied to the electromagnet is adjusted according to the wall thickness t of the tube to regulate the attraction force.

[0042]

[0043] In the formula, F ZThe total adsorption force required for the pipe-side crawling device is given by g, where g0 is the air gap between the electrode surface and the pipe when they are in contact, and the surface of the electromagnet adsorbed on the pipe is the electrode surface. t l For track wall thickness, μ l μ r The relative magnetic permeability of the track material and the pipe material are respectively, Δg=|RR e |, R is the outer radius of the pipe, R e Let θ be the radius of curvature of the pole face, θ be the sum of the coverage angles of all electromagnets at the contact position, n be the number of all electromagnets at the contact position, A be the contact area between all electromagnets at the contact position and the pipe, μ0 be the permeability of free space, and N be the number of coil turns of each electromagnet.

[0044] Fourthly, the present invention also proposes a pipe outer wall crawling device for variable pipe diameter, including a track for walking on the outer wall of a metal pipe and a main structure mounted on the track for driving the track to walk.

[0045] The main structure includes a drive mechanism, a controller, a pipe outer wall contact surface adjustment mechanism and a track tension adjustment mechanism located on opposite sides of the pipe outer wall contact surface adjustment mechanism, and a pipe diameter measuring instrument for detecting the pipe outer ring radius R in the track travel direction.

[0046] The drive mechanism includes a driving wheel, a driven wheel, a connecting rod that links the driving wheel and the driven wheel, and a motor that drives the driving wheel.

[0047] The pipe outer wall contact surface adjustment mechanism includes two hydraulic struts, two support rods, and two support wheels. One end of each of the two hydraulic struts and one end of each support rod are movably connected to the same side of the connecting rod. The other ends of the two hydraulic struts are rotatably connected to the other ends of the two support rods. Two support wheels are respectively installed on the end faces of the two support rods away from the connecting rod.

[0048] The track tension adjustment mechanism includes a second hydraulic strut, a second support rod, and a tensioning wheel. One end of the second hydraulic strut and the second support rod are movably connected to the opposite side of the connecting rod, and the other end of the second hydraulic strut is rotatably connected to the other end of the second support rod. The tensioning wheel is installed on the end face of the second support rod away from the connecting rod. The drive wheel, the driven wheel, the two support wheels, and the tensioning wheel together support the track. By driving the two support wheels, the contact area of ​​the track when it walks on the outer wall of the pipe is stabilized. The tensioning wheel adjusts the friction between the track and each wheel. The drive wheel and the driven wheel drive the track to move.

[0049] The controller is used to adjust the extension and retraction of each hydraulic strut according to the outer ring radius R of the pipeline, using any of the above-mentioned crawling methods for the outer wall of the variable diameter pipeline, so that the track can adapt to the variable diameter pipeline.

[0050] (3) Beneficial effects

[0051] 1. This invention proposes a method for crawling on the outer wall of pipes with variable wall thickness. It requires the design of a pipe crawling device (the device includes a track for moving along the outer wall of a metal pipe and multiple electromagnets connected in series within the track and arranged in the same ring as the track; the electromagnets possess a metal attraction force when energized, so that all electromagnets at the contact point between the track and the pipe provide an attraction force to the pipe). The attraction force of the crawling device on the pipe is controlled by controlling the amount of current transmitted from the power supply to the magnets, enabling the crawling device to crawl on different pipes. This solves the technical problem of existing technologies being unable to crawl on pipes with different wall thicknesses, allowing the crawling device to crawl on the outside of pipes with varying wall thicknesses.

[0052] 2. This invention utilizes the hydraulic telescopic rod of the crawler mechanism to enable the crawling device to travel on pipes of varying diameters. When crawling on the outer surface of a small-diameter pipe, the inner hydraulic push rod extends, while the connecting rod length remains constant, reducing the contact area between the track and the outer wall of the pipe. When encountering a large-diameter pipe, the hydraulic rod retracts, increasing the contact area between the track and the outer wall of the pipe.

[0053] 3. The present invention uses a triangular track mechanism, so the crawling device of the present invention is small in size and simple in structure. Attached Figure Description

[0054] Figure 1 This is an installation diagram of a pipe crawling device for variable pipe diameter and variable pipe wall thickness provided in Embodiment 1 of the present invention.

[0055] Figure 2 yes Figure 1 A top view diagram.

[0056] Figure 3 yes Figure 1 A schematic diagram of the main structure of the crawling equipment for pipeline crawling.

[0057] Figure 4 yes Figure 1 A perspective view of the track structure of a pipeline crawler.

[0058] Figure 5 yes Figure 1 A diagram showing the force analysis of the crawling equipment on the pipeline.

[0059] Figure 6 This is a flowchart illustrating a pipe wall crawling method for pipes with variable wall thickness provided in Embodiment 2.

[0060] Figure 7 This is a flowchart illustrating a pipe wall crawling method for variable diameter pipes provided in Embodiment 3. Detailed Implementation

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0064] Example 1

[0065] Embodiment 1 of the present invention provides a pipe external wall crawling device for pipes with variable diameter and variable wall thickness, which can be used to crawl on pipes with variable diameter and variable wall thickness.

[0066] Please refer to the following: Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the installation of the pipe external wall crawling device provided in this embodiment. Figure 2 for Figure 1 A top-view schematic diagram. The pipe external wall crawling device is installed on pipe 2, closely adhering to the outer wall of pipe 2, and can crawl upwards, downwards, or remain stationary on pipe 2. The pipe external wall crawling device includes multiple crawling mechanisms 1 and multiple crawling auxiliary mechanisms 3. The multiple crawling mechanisms 1 are evenly distributed around pipe 2, and a crawling auxiliary mechanism 3 is installed between two adjacent crawling mechanisms 1 to assist the multiple crawling mechanisms 1 in encircling and crawling the pipe 2.

[0067] In this embodiment, three crawling mechanisms 1 are used as an example. However, in other embodiments, the number of crawling mechanisms 1 can be one, two, or more. When there is only one crawling mechanism 1, the crawling auxiliary mechanism can be designed to be mounted (e.g., rotatably connected) at both ends around the pipe, assisting the crawling mechanism 1 in crawling around the pipe. The crawling auxiliary mechanism 3 can be at least one connecting arm. In this embodiment, there are two connecting arms, each with its two ends rotatably connected to two corresponding crawling mechanisms 1. When the connecting arm is rotatably connected to the corresponding crawling mechanism 1, a protrusion can be provided on the crawling mechanism 1, and a recess can be provided at the end of the connecting arm to accommodate the protrusion. Then, a pin can be used to rotatably position the protrusion within the recess.

[0068] Each crawler mechanism includes 13 tracks and a main structure mounted on the tracks 13 for driving the tracks 13. Please refer to... Figure 3 , Figure 3 yes Figure 1 A schematic diagram of the main structure of the crawler device. The main structure may include a drive mechanism, a pipe outer wall contact surface adjustment mechanism, a track tension adjustment mechanism, a pipe thickness gauge, a pipe diameter measuring instrument, and a controller. The drive mechanism is used to drive the track 13 to move; the pipe outer wall contact surface adjustment mechanism is used to adjust the contact surface between the track 13 and the outer wall of the pipe 2; the track tension adjustment mechanism is used to adjust the tension of the track 13; the pipe thickness gauge is used to detect the pipe wall thickness t of the pipe 2 in the direction of travel of the track 13; the pipe diameter measuring instrument is used to detect the outer circumference R of the pipe 2 in the direction of travel of the track 13; the controller is used to control the adjustment degree of the pipe outer wall contact surface adjustment mechanism, the adjustment degree of the track tension adjustment mechanism, and to adjust the adhesion force of the track 13 on the pipe 2 according to the pipe wall thickness t.

[0069] The drive mechanism may include a drive wheel 11, a driven wheel 16, a connecting rod 12 that links the drive wheel 11 and the driven wheel 16, and a motor 5 for the drive wheel 11. The pipe outer wall contact surface adjustment mechanism includes two hydraulic struts 14, two support rods 19, and two support wheels 15. One end of each of the two hydraulic struts 14 and one end of each of the two support rods 19 are movably connected to the same side of the connecting rod 12. The other ends of the two hydraulic struts 14 are rotatably connected to the other ends of the two support rods 19. Two support wheels 15 are respectively mounted on the end faces of the two support rods 19 away from the connecting rod 12. In this embodiment, one hydraulic strut 14, one support rod 19, and one support wheel 15 can constitute a support structure, and the two support structures can be fixed symmetrically. One side of hydraulic strut 14 is fixed to connecting rod 12, near the drive wheel 11 or driven wheel 16, while the other side is fixed to the middle of support rod 19. One side of support rod 19 is fixed to the middle of connecting rod 12, and the other side is fixed to a support wheel 15. The support wheel 15 is close to the track 13. The two support structures are symmetrical, and the direction of movement of the support wheel 15 is the same as that of the drive wheel 11. The support wheel 15 guides the track 13, keeping it on the correct track through rolling friction, and is close to the pipe 2 through the track 13. Hydraulic strut 14 supports support rod 19. Support rod 19 fixes the support wheel 15, allowing it to move within a fixed range. Hydraulic strut 14 can change its length, while support rod 19 remains constant. By changing its length, hydraulic strut 14 alters the distance between the two support wheels 15, thereby changing the contact area between the track 13 and the pipe 2. Therefore, when the length of the hydraulic strut 14 decreases or increases, the support rod 19 moves along with the hydraulic strut 14, causing the support wheel 15 to move, thereby changing the distance between the two support wheels 15 and thus changing the contact area between the track 13 and the pipe 2. Therefore, by changing the length of the hydraulic strut 14, the contact area between the track 13 and the pipe 2 can be changed.

[0070] The track tension adjustment mechanism includes a second hydraulic strut 20, a second support rod 17, and a tensioning wheel 18. One end of both the second hydraulic strut 20 and the second support rod 17 is movably connected to the opposite side of the connecting rod 12. The other end of the second hydraulic strut 20 is rotatably connected to the other end of the second support rod 17. The tensioning wheel 18 is mounted on the end face of the second support rod 17 away from the connecting rod 12. In this embodiment, one side of the second support rod 17 is fixed to the connecting rod 12, near the drive wheel 11 or driven wheel 16, and the other side is fixed with a tensioning wheel 18. The tensioning wheel 18 is in contact with the track 13 and moves in the same direction as the drive wheel 11. One side of the second hydraulic strut 20 is fixed to the second support rod 17, near the tensioning wheel 18, and the other side is fixed to the connecting rod 12, in the opposite position to the second support rod 17. Hydraulic strut 20 supports support rod 17, which in turn fixes the range of motion of tension wheel 18. Tension wheel 18 controls the tension of track 13. Hydraulic strut 20 changes the position of support rod 17 by altering its length, thereby changing the position of tension wheel 18. Tension wheel 18 forms a surface with drive wheel 11 and driven wheel 16. When the position of tension wheel 18 changes, the distance between tension wheel 18 and connecting rod 12 changes, thus changing the area and consequently altering the tension of track 13. Therefore, changing the length of hydraulic strut 20 changes the tension of track 13.

[0071] The drive wheel 11, driven wheel 16, two support wheels 15, and tension wheel 18 together support the track 13. Driving the two support wheels 15 stabilizes the contact area of ​​the track 13 as it travels on the outer wall of the pipe 2. The tension wheel 18 adjusts the friction between the track 13 and each wheel. The drive wheel 11 and driven wheel 16 drive the track. Therefore, the motor 5 provides the driving force, the drive wheel 11 provides the power output, and the connecting rod 12 links the drive wheel 11 and driven wheel 16 and fixes the internal components of the main structure. The driven wheel 16 guides the direction of movement of the track 13. The drive wheel 11 and driven wheel 16 move in the same direction. Specifically, the motor 5 outputs driving force to the drive wheel 11, causing it to rotate. The rotation of the drive wheel 11 drives the guide wheel 16, thus initiating the crawling motion of the device. Therefore, changing the driving energy output by the motor 5 changes the motion state of the main structure.

[0072] The pipe diameter measuring instrument can include three sensors, such as a laser displacement sensor, a laser triangulation sensor, and a laser scanning radar (2D / 3D LiDAR). These three sensors are installed in a plane perpendicular to the pipe's axial direction, arranged at a 120-degree angle. By collecting information from these three sensors, real-time measurement of the pipe's outer diameter is achieved. The point cloud data obtained from the scanning is used to create a 3D model of the pipe, guiding the subsequent adjustment of the hydraulic telescopic rod's elongation in the tracked mechanism to achieve diameter reduction. Simultaneously, a guide rail is installed on the connecting structure to allow radial movement relative to the pipe. A distance measuring sensor is mounted on this guide rail to measure the distance to the pipe's outer surface, thus maintaining a relatively constant position of the sensor relative to the pipe's surface.

[0073] After the pipe diameter measuring instrument detects the outer ring radius R of the pipe 2 in the direction of travel of the track 13, it transmits the data to the controller. This transmission can be wired or wireless (e.g., WIFI, Bluetooth, GPS). The controller adjusts the extension and retraction of each hydraulic strut according to the pipe's outer ring radius R based on a fitted curve. This fitted curve is derived by matching the extension and retraction of each support wheel to different R values. The required extension and retraction of each support wheel to different R values ​​can be obtained experimentally, allowing for data fitting to obtain the fitted curve. Therefore, the controller can adjust the extension and retraction of each hydraulic strut according to the pipe's outer ring radius R, enabling the track to adapt to pipes with varying diameters. The external wall crawling device of this invention achieves crawling on pipes of different diameters through the hydraulic telescopic rods of the track crawling mechanism. When crawling on the outer surface of a small-diameter pipe, the inner hydraulic push rod extends, while the connecting rod length remains unchanged, reducing the contact area between the track and the pipe's outer wall. When encountering a large-diameter pipe, the hydraulic rod retracts, increasing the contact area between the track and the pipe's outer wall. The external wall crawling device of the present invention solves the technical problem that the prior art is difficult to crawl on pipes 2 of different diameters, enabling the crawling device to crawl outside pipes 2 of different diameters.

[0074] Please see Figure 4 Each track 13 contains a number of electromagnets 132. These electromagnets 132 are connected in series and arranged in the same ring as the track 13. When energized, the electromagnets 132 have a metallic attraction force, so that all the electromagnets 132 located at the contact position between the track 13 and the pipe 2 provide an attraction force to the pipe 2. The electromagnets 132 can be directly fixed to the corresponding built-in part of the track 13, or multiple protrusions (such as multiple integrally formed bulges) can be provided in the inner ring of the track 13, with each protrusion housing one electromagnet 132. Of course, there are many other ways to fix the electromagnets 132 in the track 13. In order to better position the electromagnets 132, a spring 133 can also be fixed between each protrusion and the inner ring of the track 13. The spring 133 is used to provide elastic force to the corresponding electromagnet 132 when it contacts the outer wall of the pipe 2.

[0075] In this embodiment, each track 13 may include a flexible inner ring 131, multiple electromagnets 132, multiple springs 133, and a flexible outer ring 134. The flexible inner ring 131 of the track is close to the pipe 2 and has multiple protrusions. Each protrusion houses an electromagnet 132, which are connected in series. When energized, the electromagnets 132 have a metallic attraction force, providing an attraction force for the crawling device to adhere to the pipe 2. A spring 133 is fixed between each protrusion and the inner ring 131. The spring 133 provides elastic force to the corresponding electromagnet 132 when it contacts the outer wall of the pipe. Specifically, current is input to the electromagnet 132, which then generates an attraction force, causing the crawling device to adhere to the pipe 2 and crawl on it.

[0076] Pipe thickness gauges can use detection sensors, such as ultrasonic thickness gauges, to measure the pipe wall thickness. These sensors are mounted on the connecting mechanism. Because existing continuous measurement equipment is too large and has significant limitations on movement speed, this embodiment is designed to perform a stop-motion wall thickness measurement every other longitudinal length of the equipment. Three thickness gauge probes are installed at the top, one every 120 degrees. A guide rail is installed on the connecting structure to allow radial movement relative to the pipe. These three probes can extend along the equipment's axial direction towards the pipe for one longitudinal distance. Two measurement methods are used: measuring the closest and furthest sections, and the average value is taken. The difference between the average and the minimum value is observed to ensure that the values ​​within this range allow the equipment to function normally.

[0077] The controller adjusts the current I supplied to the electromagnet 132 according to the pipe wall thickness t, thereby regulating the attraction force.

[0078]

[0079] In the formula, F Z The total adsorption force required by the pipe external wall crawling device, when the pipe external wall crawling device has multiple crawling mechanisms 1, is F. Z The total adsorption force required for each crawling mechanism. g0 is the air gap between the electrode surface and pipe 2 when they are in contact. The surface of electromagnet 132 adsorbed on pipe 2 is the electrode surface. t l For track wall thickness, μ l μ r These are the relative magnetic permeabilities of the track material and the pipe material, respectively. Δg=|RR e |, R is the outer radius of pipe 2, R eθ is the radius of curvature of the pole face. θ is the sum of the coverage angles of all electromagnets 132 at the contact position, n is the number of all electromagnets 132 at the contact position, A is the contact area between all electromagnets 132 at the contact position and the pipe, μ0 is the permeability of free space, and N is the number of coil turns of each electromagnet 132.

[0080] F Z satisfy:

[0081] The crawling device remains stationary and does not slide on the outer wall of pipe 2: μ s F Z ≥mg sinβ,

[0082] The crawling device crawls upwards on the outer wall of pipe 2: F d >mg sinβ+μ k F z ,

[0083] The crawling device crawls downwards on the outer wall of pipe 2: F d >μ k F z -mg sinβ,

[0084] In the formula, β is the angle between the axis of pipe 2 and the horizontal plane, and F d For the driving force of the crawling device, μ k Let μ be the coefficient of dynamic friction between track 13 and the outer wall of pipe 2. s denoted as the static friction coefficient between track 13 and the outer wall of pipe 2, and mg as the weight of the crawling equipment.

[0085] Therefore, the controller can also adjust the current I supplied to the electromagnet according to the pipe wall thickness t to adjust the adsorption force. The pipe wall crawling device of the present invention controls the adsorption force of the crawling device on the pipe by controlling the amount of current transmitted from the power supply to the magnet, so that the crawling device can crawl on different pipes, solving the technical problem that the prior art is difficult to crawl on pipes with different wall thicknesses, and enabling the crawling device to crawl on the outside of pipes with different wall thicknesses.

[0086] It should be noted that adjusting the current I requires knowing the specific diameter of pipe 2. Therefore, if the pipe crawling device is not equipped with a pipe diameter measuring instrument, it can only crawl on pipes with a known diameter, and then the current I is adjusted according to the different pipe wall thicknesses. Based on different pipe diameters or different pipe diameter ranges, the coverage angle θ of all electromagnets 132 at the contact position, the number n of all electromagnets 132 at the contact position, and the contact area A between all electromagnets 132 at the contact position and the pipe can be obtained through prior experiments. Therefore, when the pipe diameter value is obtained, θ, n, A, etc., can be determined by looking up tables or relationship curves.

[0087] Please seeFigure 5 , Figure 5 for Figure 5 This diagram illustrates the force analysis of a crawling device as it crawls along a pipe, showing the forces acting on the device as it climbs upwards along a vertical pipe.

[0088] in,

[0089] F m It is the attraction force generated by the electromagnet; F N It is the supporting force; Mg is gravity; F is the supporting force. d It is the driving force; F f It is friction; μ k It is the coefficient of dynamic friction between the track and the outer wall of the pipe; the attraction force generated by the electromagnet:

[0090] in:

[0091] N is the number of turns in the coil.

[0092] I is the current (A).

[0093] μ r It is the relative magnetic permeability of the pipe material.

[0094] μ0 is the vacuum permeability.

[0095] A is the contact area between the electromagnet and the pipe (m²) 2 ).

[0096] t is the pipe wall thickness (m).

[0097] Because the outer surface of the pipe is curved, although this patent uses flexible track plates to allow the track plates to adhere to the outer surface of the pipe as closely as possible, air gaps may still exist. Therefore, the total air gap g t =g0+Δg.

[0098] Where g0 is the air gap between the electromagnet pole face and the pipe, Δg=|RR e |,R is the actual outer radius of the pipe (m), R e It is the radius of curvature of the electromagnet's pole face. Therefore, the total attraction force on the pipe at this time is as follows:

[0099]

[0100] Where: θ is the sum of the actual coverage angles of all electromagnets, and n is the number of electromagnets.

[0101] And F Z The following conditions must be met:

[0102] 1. The crawling device remains stationary and does not slide on the outer wall of the pipe: μ s F Z≥mg sinβ;

[0103] 2. The crawling device climbs upwards on the outer wall of the pipe: F d >mg sinβ+μ k F z ;

[0104] 3. The crawling equipment crawls downwards on the outer wall of the pipe: F d >μ k F z -mg sinβ;

[0105] Where β is the angle between the pipe axis and the horizontal plane, and F d For the driving force of the crawling device, μ k Let μ be the coefficient of dynamic friction between the track and the outer wall of the pipe. s Let be the static friction coefficient between the track and the outer wall of the pipe, and mg be the weight of the crawler.

[0106] In this embodiment, the current supplied to the electromagnet 132 can be supplied by the crawling device's own power supply or by an external power supply. Any device that can supply current to the electromagnet 132 can be used, and there are no limitations.

[0107] Example 2

[0108] Embodiment 2 of the present invention provides a method for crawling along the outer wall of a pipe with variable wall thickness. Please refer to [link / reference]. Figure 6 The method for crawling along the outer wall of a pipe with variable wall thickness mainly includes the following steps. Step 1: Provide the pipe outer wall crawling device described in Example 1.

[0109] Of course, it can also be a pipe external wall crawling device, which mainly includes a track for walking on the outer wall of a metal pipe and multiple electromagnets connected in series and installed inside the track in the same ring as the track. When energized, the electromagnets have a metal attraction force, so that all the electromagnets at the contact position between the track and the pipe provide an attraction force to the pipe.

[0110] Step 2: Detect the pipe wall thickness t of the pipe in the direction of travel of track 13.

[0111] For example, the pipe thickness gauge of Example 1 can be used to detect the pipe wall thickness t in the direction of travel of the track 13.

[0112] Step 3: Adjust the current I supplied to the electromagnet according to the pipe wall thickness t to adjust the attraction force.

[0113]

[0114] In the formula, F ZThe total adsorption force required for the pipe-side crawling device is given by g, where g0 is the air gap between the electrode surface and the pipe when they are in contact, and the surface of the electromagnet adsorbed on the pipe is the electrode surface. t l For track wall thickness, μ l μ r The relative magnetic permeability of the track material and the pipe material are respectively, Δg=|RR e |, R is the outer radius of the pipe, R e Let θ be the radius of curvature of the pole face, θ be the sum of the coverage angles of all electromagnets at the contact position, n be the number of all electromagnets at the contact position, A be the contact area between all electromagnets at the contact position and the pipe, μ0 be the permeability of free space, and N be the number of coil turns of each electromagnet.

[0115] For example, the controller of Example 1 can be used to adjust the current I supplied to the electromagnet according to the wall thickness t of the tube, so as to adjust the adsorption force.

[0116] Example 3

[0117] This embodiment 3 provides a method for crawling along the outer wall of a pipe with a variable diameter. Please refer to [link / reference]. Figure 7 The crawling method for the outer wall of pipes with variable diameters mainly includes the following steps.

[0118] Step 1: Provide the pipe crawling device described in Example 1.

[0119] Of course, the pipe crawling device described in Example 1 may not be used, but the main structure of the crawling device in Example 1 is required.

[0120] Step 2: Detect the outer ring radius R of the pipe in the direction of track travel.

[0121] For example, the pipe diameter measuring instrument of Example 1 can be used to detect the outer ring radius R of the pipe in the direction of travel of the track 13.

[0122] Step 3: Adjust the extension and retraction of each hydraulic strut according to the fitting relationship curve based on the outer ring radius R of the pipeline, so that the crawling equipment can grip the pipeline tightly and the tracks can adapt to the variable diameter pipeline; the fitting relationship curve is fitted according to the extension and retraction of each support wheel to match different R values.

[0123] For example, the controller of Example 1 can be used to complete the function of step three.

[0124] Example 4

[0125] This embodiment 4 provides a control method for a pipe wall crawling device with variable pipe diameter and variable pipe wall thickness. The control method includes the following steps:

[0126] Provide the pipe crawling device described in Embodiment 1;

[0127] The pipe diameter measuring instrument described in Example 1 is used to detect the outer ring radius R of the pipe in the direction of track travel;

[0128] The pipe wall thickness t of the pipe in the direction of travel of the track 13 is detected using the pipe thickness gauge described in Example 1.

[0129] First, adjust the extension and retraction of each hydraulic strut according to the fitting relationship curve based on the outer ring radius R of the pipeline, so that the crawling equipment can grip the pipeline tightly and the tracks can adapt to the variable diameter pipeline.

[0130] Then, based on the pipe wall thickness t, the current I supplied to the electromagnet is calculated and adjusted to regulate the attraction force.

[0131]

[0132] In the formula, F Z The total adsorption force required for the pipe-side crawling device is given by g, where g0 is the air gap between the electrode surface and the pipe when they are in contact, and the surface of the electromagnet adsorbed on the pipe is the electrode surface. t l For track wall thickness, μ l μ r The relative magnetic permeability of the track material and the pipe material are respectively, Δg=|RR e |, R is the outer radius of the pipe, R e Let θ be the radius of curvature of the pole face, θ be the sum of the coverage angles of all electromagnets at the contact position, n be the number of all electromagnets at the contact position, A be the contact area between all electromagnets at the contact position and the pipe, μ0 be the permeability of free space, and N be the number of coil turns of each electromagnet.

[0133] The controller adjusts the extension and retraction of the hydraulic struts and the current supplied to the electromagnet, enabling the pipe crawling mechanism to fit snugly against the pipe and crawl smoothly along it.

[0134] In summary, the core advantages of this invention are as follows:

[0135] 1. The overall design uses a triangle to center the robot along the pipe, ensuring that the robot can move stably along the pipe.

[0136] 2. Other electrical control equipment, pipeline inspection equipment, or maintenance equipment can be mounted on the connecting rod between the two tracked devices.

[0137] 3. It possesses obstacle-crossing and diameter-adjusting capabilities. When encountering obstacles, the front end of the track mechanism tilts upward, creating a maximum clearance angle, thus preventing obstacles from hindering the robot's forward movement. Simultaneously, the track mechanism features a hydraulic telescopic rod, allowing the inner hydraulic push rod to extend when crawling on the outer surface of small-diameter pipes. At this time, the connecting rod length remains unchanged, reducing the contact area between the track and the pipe's outer wall. When encountering large-diameter pipes, the hydraulic rod retracts, increasing the contact area between the track and the pipe's outer wall.

[0138] 4. It has the ability to generate variable adsorption force. When the pipeline is a magnetic pipeline, the track mechanism has been technically improved. The improved track includes a flexible outer ring, multiple magnets, multiple springs, and a flexible inner ring. Different adsorption forces can be obtained by inputting different currents to the magnets. At this time, the crawling device can crawl on different pipelines.

[0139] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0140] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method of pipe external wall crawling oriented to variable pipe wall thickness, characterized by, It comprises the following steps: Providing a pipeline outer wall crawling device, which comprises: a caterpillar for walking on the outer wall of a metal pipeline; and a plurality of series-connected electromagnets arranged in the caterpillar and in the same ring as the caterpillar, the electromagnets having metal adsorption force under energized condition, so that all the electromagnets at the contact position of the caterpillar and the pipeline provide adsorption force to the pipeline; Detecting the pipe wall thickness t of the pipeline in the advancing direction of the caterpillar; Adjusting the current I supplied to the electromagnets according to the pipe wall thickness t to adjust the adsorption force: In the formula, F Z is the total adsorption force required by the pipeline outer wall crawling device, g0 is the air gap between the pole surface and the pipeline when they are in contact, the surface of the electromagnet adsorbed on the pipeline is the pole surface, t l is the track wall thickness, μ l , μ r are the relative magnetic permeability of the track material and the pipeline material respectively, Δg = |R-R e |, R is the outer ring radius of the pipeline, R e is the curvature radius of the pole surface, θ is the coverage angle of all electromagnets at the contact position, n is the number of all electromagnets at the contact position, A is the contact area of all electromagnets at the contact position and the pipeline, μ0 is the vacuum magnetic permeability, and N is the number of turns of each electromagnet.

2. The variable wall thickness oriented pipe exterior wall crawling method according to claim 1, characterized by, F Z satisfies: Crawling device is stationary on the outer wall of the pipe: μ s F Z ≥ mgsinβ, Crawling device climbs up on the outer wall of the pipe: F d > mgsinβ+μ k F z , The crawling device crawls down the outer wall of the pipe: F d > μ k F z - mgsinβ, where β is the angle between the pipeline axis and the horizontal plane, F d is the driving force of the crawling device, μ k is the dynamic friction coefficient between the crawler and the outer wall of the pipeline, μ s is the static friction coefficient between the crawler and the outer wall of the pipeline, and mg is the gravity of the crawling device.

3. A pipeline outer wall crawling device for variable pipe wall thickness, comprising: a caterpillar for walking on the outer wall of a metal pipeline; characterized in that a plurality of series-connected electromagnets arranged in the caterpillar and in the same ring as the caterpillar are installed in the caterpillar, the electromagnets having metal adsorption force under energized condition, so that all the electromagnets at the contact position of the caterpillar and the pipeline provide adsorption force to the pipeline; The pipeline outer wall crawling device further comprises: a pipeline thickness gauge for detecting the pipe wall thickness t of the pipeline in the advancing direction of the caterpillar; a controller for adjusting the current I supplied to the electromagnets according to the pipe wall thickness t to adjust the adsorption force by using the pipeline outer wall crawling method for variable pipe wall thickness as claimed in claim 1 or 2.

4. The pipeline outer wall crawling device for variable pipe wall thickness as claimed in claim 3, characterized in that: the pipeline outer wall crawling device comprises: a crawling mechanism comprising the caterpillar and a main body structure installed on the caterpillar and used for driving the caterpillar to walk; a crawling auxiliary mechanism installed on the main body structure behind both ends of the pipeline and used for assisting the crawling mechanism to encircle the pipeline to realize crawling; or, the pipeline outer wall crawling device comprises: a plurality of crawling mechanisms are uniformly arranged around the pipeline as a center, each of the crawling mechanisms comprises the track and a main structure installed on the track and used for driving the track to move, at this time, F Z total adsorption force required for each of the crawling mechanisms; a plurality of crawling auxiliary mechanisms, one of which is installed between two adjacent crawling mechanisms and used for assisting the plurality of crawling mechanisms to encircle the pipeline to realize crawling; and / or, the inner ring of the caterpillar has a plurality of protrusions, and each protrusion accommodates an electromagnet.

5. The variable wall thickness oriented pipe external wall climbing apparatus according to claim 3, characterized by, The inner ring of the caterpillar has a plurality of protrusions, and each protrusion accommodates an electromagnet, and a spring is fixed between each protrusion and the inner ring of the caterpillar, and the spring is used to provide elastic force to the corresponding electromagnet when the corresponding electromagnet contacts the outer wall of the pipeline.

6. The variable wall thickness oriented pipe external wall climbing apparatus according to claim 3, characterized by, The crawling device further comprises a main body structure installed on the caterpillar and used for driving the caterpillar to walk; The main body structure comprises: a driving mechanism comprising a driving wheel, a driven wheel, a connecting rod connected between the driving wheel and the driven wheel, and a motor driving the driving wheel to operate; a pipeline outer wall contact surface adjusting mechanism comprising two hydraulic support rods, two support rods, and two support wheels; one end of each of the two hydraulic support rods and one end of each of the two support rods are movably connected to the same side of the connecting rod, the other end of each of the two hydraulic support rods is rotatably connected to the other end of each of the two support rods, and two support wheels are respectively installed on the end faces of the two support rods away from the connecting rod; a caterpillar tension adjusting mechanism comprising a hydraulic support rod, a support rod, and a tensioning wheel; one end of each of the hydraulic support rod and the support rod is movably connected to the opposite side of the connecting rod, the other end of the hydraulic support rod is rotatably connected to the other end of the support rod, and a tensioning wheel is installed on the end face of the support rod away from the connecting rod; The driving wheel, the driven wheel, the two supporting wheels and the tensioning wheel jointly support the track, the two supporting wheels stabilize the contact area of the track when the track walks on the outer wall of the pipeline, the tensioning wheel adjusts the friction between the track and each wheel, and the driving wheel and the driven wheel drive the track to walk.

7. A variable wall thickness oriented pipe external wall climbing apparatus according to claim 6, characterized in that, The pipeline outer wall crawling device further comprises a pipe diameter measuring instrument for detecting the outer ring radius R of the pipeline in the advancing direction of the track; The controller is further configured to adjust the extension and retraction of each hydraulic support rod according to the pipeline outer ring radius R based on a fitting relationship curve, and the fitting relationship curve is fitted according to the extension and retraction required by each supporting wheel for different R.

8. A method of pipe external wall crawling oriented to a variable pipe diameter, characterized by, It comprises the following steps: A pipeline outer wall crawling device is provided, which comprises a track for walking on the outer wall of a metal pipeline, and a main structure mounted on the track and used for driving the track to walk; the main structure comprises a driving mechanism, a pipeline outer wall contact surface adjusting mechanism and a track tension adjusting mechanism respectively located on opposite sides of the pipeline outer wall contact surface adjusting mechanism, and a pipe diameter measuring instrument for detecting the outer ring radius R of the pipeline in the advancing direction of the track; the driving mechanism comprises a driving wheel, a driven wheel, a connecting rod connected between the driving wheel and the driven wheel, and a motor for driving the driving wheel to operate; the pipeline outer wall contact surface adjusting mechanism comprises two hydraulic support rods, two supporting rods and two supporting wheels; one end of each of the two hydraulic support rods and one end of each of the two supporting rods are movably connected to the same side of the connecting rod, the other end of each of the two hydraulic support rods is rotatably connected to the other end of each of the two supporting rods, and two supporting wheels are respectively mounted on the end faces of the two supporting rods away from the connecting rod; the track tension adjusting mechanism comprises a hydraulic support rod, a supporting rod and a tensioning wheel; one end of each of the hydraulic support rod and the supporting rod is movably connected to the opposite side of the connecting rod, the other end of the hydraulic support rod is rotatably connected to the other end of the supporting rod, and the tensioning wheel is mounted on the end face of the supporting rod away from the connecting rod; wherein the driving wheel, the driven wheel, the two supporting wheels and the tensioning wheel jointly support the track, the two supporting wheels stabilize the contact area of the track when the track walks on the outer wall of the pipeline, the tensioning wheel adjusts the friction between the track and each wheel, and the driving wheel and the driven wheel drive the track to walk; Detecting the outer ring radius R of the pipeline in the advancing direction of the track; Adjusting the extension and retraction of each hydraulic support rod according to the pipeline outer ring radius R based on a fitting relationship curve, so that the track adapts to the variable diameter pipeline; the fitting relationship curve is fitted according to the extension and retraction required by each supporting wheel for different R.

9. The variable pipe diameter oriented pipe exterior wall crawling method according to claim 8, characterized by, The pipeline outer wall crawling device further comprises a plurality of series-connected electromagnets mounted in the track and arranged in the same ring as the track, and the electromagnets have metal adsorption force under the condition of being energized, so that all the electromagnets at the contact position of the track with the pipeline provide adsorption force to the pipeline; The pipeline outer wall crawling method for variable pipe diameter further comprises: Detecting the pipe wall thickness t of the pipeline in the advancing direction of the track; Adjusting the current I supplied to the electromagnets according to the pipe wall thickness t to adjust the adsorption force: In the formula, F Z Total adsorption force required for pipe outer wall crawling equipment, g0 is the air gap between the pole surface and the pipe when they are in contact, the surface of the electromagnet adsorbed on the pipe is the pole surface, t l The track wall thickness, μ l , μ r The relative magnetic permeability of the track material and the pipe material respectively, Δg = |R-R e |, R is the outer ring radius of the pipe, R e The radius of curvature of the pole surface, θ is the coverage angle of all electromagnets at the contact position, and n is the number of all electromagnets at the contact position, A is the contact area of all electromagnets at the contact position and the pipe, μ0 is the vacuum magnetic permeability, and N is the number of turns of each electromagnet.

10. A pipeline outer wall crawling device for variable pipe diameter, comprising: a track for walking on the outer wall of a metal pipeline; a main structure mounted on the track and used for driving the track to walk; The main body structure comprises a driving mechanism; the driving mechanism comprises a driving wheel, a driven wheel, a connecting rod connecting the driving wheel and the driven wheel, and a motor driving the driving wheel; The main body structure further comprises a controller, pipeline outer wall contact surface adjusting mechanisms respectively located on opposite sides of the pipeline outer wall contact surface adjusting mechanism, a track tension adjusting mechanism, and a pipeline diameter measuring instrument for detecting the outer ring radius R of the pipeline in the advancing direction of the track; The pipeline outer wall contact surface adjusting mechanism comprises two hydraulic support rods I, two support rods I, and two support wheels; one end of the two hydraulic support rods I and one end of the two support rods I are movably connected to the same side of the connecting rod, the other end of the two hydraulic support rods I is rotatably connected to the other end of the two support rods I, and two support wheels are respectively installed on the end faces of the two support rods I away from the connecting rod; The track tension adjusting mechanism comprises a hydraulic support rod II, a support rod II, and a tension wheel; one end of the hydraulic support rod II and one end of the support rod II are movably connected to the opposite side of the connecting rod, the other end of the hydraulic support rod II is rotatably connected to the other end of the support rod II, and the tension wheel is installed on the end face of the support rod II away from the connecting rod; wherein the driving wheel, the driven wheel, the two support wheels, and the tension wheel jointly support the track, the two support wheels stabilize the contact area of the track when walking on the pipeline outer wall, the tension wheel adjusts the friction between the track and each wheel, and the driving wheel and the driven wheel drive the track to walk; The controller is used to adjust the extension degree of each hydraulic support rod according to the pipeline outer ring radius R by using the pipeline outer wall crawling method for variable pipeline diameters as claimed in claim 8 or 9, so that the track adapts to the variable diameter pipeline.

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