A robot for inspecting the inner wall of a pipeline

Abstract

The application relates to a robot for pipeline inner wall inspection, which is a pipeline robot with multiple functions of passive follow-up steering, outer diameter self-adaptive adjustment, active track-changing steering and inspection-obstacle removal-washing integration, so as to improve the passability, steering flexibility and operation efficiency of the robot under complex pipeline working conditions. In the robot, a front end inspection operation section and a terminal washing operation section are sequentially connected through a space connecting rod universal joint; a visual detection unit and a clamping mechanism are integrally installed at the end of the front end inspection operation section; the self-adaptive driving walking section comprises a first walking section, an active steering mechanism and a second walking section; the first walking section and the second walking section independently comprise a lead screw, a connecting rod mechanism, a driving motor, an elastic shock absorbing component and a track walking component; the lead screw is connected with the driving motor; one end of the connecting rod mechanism is connected with the lead screw, and the other end is connected with the track walking component; and the elastic shock absorbing component is arranged between the lead screw and the connecting rod mechanism.

Description

Technical Field

[0001] This application relates to the field of pipeline inspection, specifically a robot for inspecting the inner wall of pipelines. Background Technology

[0002] In pipeline inspection and maintenance operations, pipeline robots need to enter complex pipeline systems to perform tasks such as inspection, obstacle removal, and cleaning. Actual pipeline networks often contain complex terrain such as right-angle bends, U-shaped bends, T-shaped branches, and continuous distribution of multiple bends. This requires pipeline robots to have excellent bend-crossing capabilities, enabling them to smoothly turn and move through curved pipe sections to avoid getting stuck or overturning. Furthermore, different pipelines have different diameters, and even within the same pipeline, there may be variations in diameter or protruding obstacles such as welds and scale. This necessitates that pipeline robots have adaptive outer diameter adjustment capabilities to ensure stable adhesion across different pipe diameter sections.

[0003] Most existing pipeline robots employ a rigid, integral body structure, with rigid connections between the front, middle, and rear sections, or simple hinges with only a single degree of freedom. When the robot enters a curve, the rigid body cannot adapt to the curve of the pipeline, and over-constraint interference easily occurs between the wheel sets or tracked walking mechanisms and the pipe wall, leading to a sharp increase in walking resistance or even jamming. Some existing solutions use hinged joints with a single rotational degree of freedom to connect the module segments, allowing adjacent modules to swing relative to each other in the horizontal plane to adapt to the curve. However, pipeline curves are three-dimensional curves, and the robot needs not only horizontal deflection when passing through curves, but also changes in the vertical orientation of the body and torsion around its own axis. Single-degree-of-freedom hinged joints cannot provide the aforementioned multi-degree-of-freedom follow-through deflection capabilities, and still suffer from insufficient maneuverability when passing through curves with large curvatures.

[0004] Regarding locomotion, existing pipeline robots mostly employ fixed-diameter locomotion mechanisms. These robots are only suitable for pipes of a single diameter and cannot adapt to changes in pipe diameter, easily becoming stuck or losing traction. Some solutions use spring-loaded variable-diameter structures, where the spring's elastic force presses the locomotion mechanism against the pipe wall, adapting to diameter changes to some extent. However, the variable-diameter range is limited, and the pressing force cannot be actively controlled. Furthermore, some solutions employ active variable-diameter mechanisms using sensors and motors. Sensors detect changes in pipe diameter and drive the motor to adjust accordingly. However, this relies on complex sensing and control systems, resulting in response delays. In the event of sudden changes in pipe diameter, the robots are prone to jamming or damage due to untimely adjustments.

[0005] In terms of turning at pipeline branch points, existing pipeline robots typically rely on external control commands combined with complex wheel differentials or steering mechanisms to change course when encountering T-shaped branch pipes or needing to actively change their direction of travel. However, such solutions are slow to turn and have complex mechanisms, making it difficult to achieve fast and accurate active course changing and turning.

[0006] In terms of functional integration, the existing pipeline robot has too simple a functional configuration and cannot efficiently complete the complete operation loop of "inspection-obstacle removal-cleaning" in a single deployment operation. This results in the need to repeatedly deploy equipment with different functions when multiple working conditions alternate, leading to low on-site construction efficiency.

[0007] Therefore, there is an urgent need in this field for a pipeline robot that integrates multiple degrees of freedom passive follow-up steering, outer diameter adaptive adjustment, active trajectory changing steering, and multiple functions such as inspection, obstacle removal, and cleaning, in order to improve the robot's passability, steering flexibility, and work efficiency in complex pipeline network conditions. Summary of the Invention

[0008] This application provides a robot for inspecting the inner wall of pipelines, which integrates multiple degrees of freedom passive follow-up steering, outer diameter adaptive adjustment, active trajectory changing steering, and multiple functions such as inspection, obstacle removal and cleaning, so as to improve the robot's passability, steering flexibility and operation efficiency in complex pipeline network conditions.

[0009] The technical solution of this application is as follows: A robot for inspecting the inner wall of a pipeline includes a front-end inspection section, an adaptive drive walking section, and an end-end cleaning section. The front-end inspection section and the adaptive drive walking section, as well as the adaptive drive walking section and the end-end cleaning section, are sequentially connected by a spatial linkage universal joint. The end of the front-end inspection section is equipped with a vision inspection unit and a clamping mechanism. The adaptive drive walking segment includes a first walking segment, a second walking segment, and an active steering mechanism connected between the first walking segment and the second walking segment. The first walking segment and the second walking segment each independently include a lead screw, a linkage mechanism, a drive motor, an elastic shock absorber assembly, and a track walking assembly. The lead screw is connected to the drive motor, one end of the linkage mechanism is connected to the lead screw, and the other end is connected to the track walking assembly. The elastic shock absorber assembly is disposed between the lead screw and the linkage mechanism. When the lead screw rotates, it drives the linkage mechanism to extend or retract, thereby causing the track walking assembly to extend outward or retract inward along the radial direction of the pipeline. The active steering mechanism is connected between the first walking section and the second walking section, and is used to drive the first walking section to actively deflect relative to the second walking section.

[0010] Preferably, the spatial link universal joint includes a link base, a cross joint, and a spatial link; The connecting rod base is provided with multiple bases and fixed to the end face of each working section. The cross joint is hinged to each connecting rod base. The spatial connecting rod spans between two adjacent working sections and its two ends are respectively hinged to the cross joint on the corresponding side.

[0011] Preferably, the cross joint has a first rotating shaft and a second rotating shaft that are perpendicular to each other. The cross joint is rotatably connected to the corresponding connecting rod base through the first rotating shaft, and is rotatably connected to the end of the corresponding spatial connecting rod through the second rotating shaft. The number of spatial links is three, and the three spatial links are symmetrically distributed at 120° intervals around the pipeline axis, and do not interfere with each other in space.

[0012] Preferably, the active steering mechanism includes a first servo motor, a second servo motor, a third servo motor, and a 90° staggered shaft belt drive mechanism; The first servo and the third servo are respectively disposed on both sides of the second servo. The second servo and the third servo are fixedly assembled. The second servo is connected to the first servo through the 90° staggered shaft belt drive mechanism.

[0013] Preferably, the 90° staggered shaft belt drive mechanism includes a driving pulley, a driven pulley, and a drive belt; The output shaft of the second servo motor is arranged vertically and connected to the driving pulley. The driving pulley is connected to the driven pulley via the transmission belt that is twisted 90° in space. The output shaft of the driven pulley is fixedly connected to the first servo motor. The axis of the driven pulley is arranged along the axial direction of the pipe. The second servo drives the active pulley to rotate in the vertical direction. The active pulley drives the driven pulley to rotate in the axial direction of the pipe through the transmission belt. The driven pulley drives the first servo to rotate in the axial direction of the pipe. The output shaft of the first servo changes direction within a 360° range around the axial direction of the pipe as the first servo rotates in the whole.

[0014] Preferably, the active steering mechanism further includes a pressure shaft, which is mounted on the drive belt to tension the drive belt and maintain the spatial torsional path of the drive belt.

[0015] Preferably, the tracked walking assembly is provided in three sets; The three sets of tracked walking components are evenly arranged around the circumference of the adaptive drive walking section. The adaptive drive walking section has three openings that correspond one-to-one with the tracked walking components. Each tracked walking component extends or retracts through the corresponding opening.

[0016] Preferably, the elastic shock-absorbing assembly includes a nut, a bolt, a first spring, and a second spring; The nut is threaded onto the threaded section of the lead screw and is fixed in axial position. The bolt passes through the nut and is screwed onto the first movable seat that is slidably mounted on the lead screw. The first spring is fitted onto the bolt's thread and is clamped between the nut and the first movable seat. The second spring is fitted onto the bolt's thread and is clamped between the nut and the bolt's end cap. The linkage mechanism includes a first link and a second link, which are cross-hinged at the middle of the link by a pin to form a scissor-type linkage structure. One end of the first connecting rod is hinged to a first fixed seat fixedly mounted on the lead screw, and the other end of the first connecting rod is hinged to the track walking assembly; One end of the second link is hinged to a first movable seat that is slidably mounted on the lead screw, and the other end of the second link is hinged to the track travel assembly.

[0017] Preferably, the visual inspection unit includes an industrial camera and a pair of LED fill lights; The industrial camera is positioned at the center of the end face of the front-end inspection section, and a pair of LED fill lights are horizontally and symmetrically fixed on the left and right sides of the industrial camera. The clamping mechanism is located below the vision detection unit, and the clamping mechanism includes: a working servo motor, a gear transmission mechanism, and double-sided grippers; The output shaft of the working servo motor is connected to the gear transmission mechanism, and the gear transmission mechanism is connected to the double-sided grippers. The working servo motor drives the double-sided grippers to open and close synchronously through the gear transmission mechanism.

[0018] Preferably, the end cleaning section includes a component sleeve, an end cap fixed to the end of the component sleeve, a tail rod fixed to the center of the end cap and extending outward, a plurality of nozzles arranged circumferentially along the tail rod, and a hose for delivering fluid medium to the nozzles. The hose is connected to the internal flow channel of the tail rod, and the nozzle is connected to the internal flow channel of the tail rod. The spray center axes of the multiple nozzles are all inclined and scattered towards the outer side of the inner wall of the pipe to form an annular high-pressure cleaning water curtain covering the inner circumference of the pipe.

[0019] The beneficial effects of this application are as follows: The front-end inspection section, adaptive drive walking section, and end-of-pipe cleaning section are sequentially connected by a spatial linkage universal joint, achieving multi-degree-of-freedom passive steering. This allows each section to adaptively deflect along the curve trajectory when the robot passes through curves, significantly improving the robot's curve-passing ability in complex pipe networks. The front-end inspection section integrates a vision inspection unit and a gripping mechanism, enabling simultaneous image acquisition of the pipe inner wall and removal of foreign objects during movement, achieving integrated inspection and obstacle removal. The adaptive drive walking section uses a lead screw and cross-link mechanism to drive the track walking assembly to extend and retract radially along the pipe, achieving active adjustment of the robot's outer diameter and adapting to pipes of different diameters. At the same time, the elastic shock absorption component uses a two-way spring structure to mechanically buffer and decouple radial impact loads, eliminating the need for sensors or controllers and fundamentally eliminating the response delay of the electronic control scheme. This effectively prevents the lead screw from jamming and being damaged due to excessive constraint. The active steering mechanism drives the 90° staggered shaft belt transmission mechanism to change direction through the second servo motor, causing the first servo motor to rotate around the pipe axis, enabling the first walking section to achieve active trajectory change and steering in any direction in the horizontal plane. At the same time, the first and third servo motors independently control the pitch and deflection of the first and second walking sections in the radial plane of the pipe, allowing the robot to flexibly choose the direction of travel and adapt to changes in pipe slope at complex pipe openings such as T-shaped branch pipes and tees. The three sets of track walking components are evenly arranged circumferentially, enabling the robot to obtain uniform radial support force and walking adhesion force in the pipe, ensuring stable and reliable walking. The end cleaning operation section sprays cleaning medium onto the inner wall of the pipe through multiple nozzles evenly arrayed along the circumference of the tail rod, forming an annular high-pressure cleaning water curtain covering the inner circumference of the pipe, achieving all-round cleaning of the inner wall of the pipe. Overall, the robot integrates inspection, obstacle removal, diameter-changing walking, active steering, and high-pressure cleaning. It also has the ability to pass through passive curves and the ability to actively change tracks and turn. It can complete the entire process of comprehensive maintenance of the inner wall of the pipeline in a single deployment, effectively improving the pipeline maintenance efficiency and the robot's environmental adaptability. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of a robot used for pipeline inner wall inspection in an embodiment of this application; Figure 2 This is a schematic diagram of the front-end inspection section in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the first walking segment in an embodiment of this application; Figure 4 This is a schematic diagram of the tracked walking assembly in an embodiment of this application; Figure 5 This is a schematic diagram of the adaptive drive walking segment in an embodiment of this application; Figure 6This is a schematic diagram of the active steering mechanism in the embodiments of this application; Figure 7 This is a schematic diagram of the active steering mechanism without a servo motor installed in the embodiments of this application; Figure 8 This is a schematic diagram of the active steering mechanism in the embodiments of this application; Figure 9 This is an assembly cross-sectional view of the driven pulley in an embodiment of this application; Figure 10 This is a schematic diagram of the spatial linkage universal joint in the embodiments of this application; Figure 11 This is a schematic diagram of the end-of-line cleaning section in an embodiment of this application. Detailed Implementation

[0021] Reference Figure 1 This application provides a robot for inspecting the inner wall of a pipeline, including a front-end inspection section 1, an adaptive drive walking section 2, and an end-end cleaning section 3. The front-end inspection section 1 and the adaptive drive walking section 2, as well as the adaptive drive walking section 2 and the end-end cleaning section 3, are sequentially connected by a spatial linkage universal joint 4.

[0022] The end of the front-end inspection section 1 is equipped with a vision inspection unit 11 and a clamping mechanism 12.

[0023] The adaptive drive walking segment 2 includes a first walking segment 201, a second walking segment 202, and an active steering mechanism connecting the first walking segment 201 and the second walking segment 202. The first walking segment 201 and the second walking segment 202 each independently include a lead screw 21, a linkage mechanism 22, an elastic shock absorber assembly 23, and a track walking assembly 24. The lead screw 21 is connected to a drive motor. One end of the linkage mechanism 22 is connected to the lead screw 21, and the other end is connected to the track walking assembly 24. The elastic shock absorber assembly 23 is disposed between the lead screw 21 and the linkage mechanism 22. When the lead screw 21 rotates, it drives the linkage mechanism 22 to extend or retract, thereby causing the track walking assembly 24 to extend outward or retract inward along the radial direction of the pipe, achieving active adjustment of the robot's outer diameter. The active steering mechanism is connected between the first walking segment 201 and the second walking segment 202 and is used to drive the first walking segment 201 to actively deflect relative to the second walking segment 202, enabling the robot to actively change its direction of travel at complex pipe openings such as T-shaped branch pipes and tees.

[0024] Reference Figure 2In this embodiment, a vision inspection unit 11 and a clamping mechanism 12 are integrated and installed at the end of the front-end inspection section 1. The vision inspection unit 11 is located at the center of the end face of the front-end inspection section 1 and includes an industrial camera 111 and a pair of LED fill lights 112. The industrial camera 111 is used to acquire high-definition images of the inside of the pipeline in real time. The pair of LED fill lights 112 are horizontally and symmetrically fixed on the left and right sides of the industrial camera 111 to provide coaxial uniform illumination in dark environments, ensuring that the industrial camera 111 can acquire clear image information in the dark pipeline.

[0025] The clamping mechanism 12 is located below the vision inspection unit 11 and includes a working servo motor 121, a gear transmission mechanism 122, and dual-sided grippers 123. The working servo motor 121 is installed inside the front-end inspection section 1. The output shaft of the working servo motor 121 is connected to the gear transmission mechanism 122, which is connected to the dual-sided grippers 123. When the working servo motor 121 is activated, it drives the dual-sided grippers 123 to synchronously close or open in the horizontal plane via the gear transmission mechanism 122 to clamp and remove foreign objects in the pipe. When the dual-sided grippers 123 are closed, they can grab, break, and remove dead scale, large foreign objects, or accumulated debris stuck on the inner wall of the pipe, effectively clearing the pipe.

[0026] Reference Figure 3 In the first traveling section 201 and the second traveling section 202, there are two sets of linkage mechanisms 22, namely the first linkage mechanism and the second linkage mechanism, which are respectively connected to the two ends of the track traveling assembly 24 in the axial direction.

[0027] The first traveling section 201 and the second traveling section 202 each independently include a lead screw 21, a linkage mechanism 22, an elastic shock-absorbing assembly 23, and a track traveling assembly 24. The lead screw 21 is arranged along the axial direction of the pipe, and one end of the lead screw 21 is connected to the output shaft of the drive motor 27, which drives it to rotate. The lead screw 21 has a smooth section and a threaded section. A first fixed seat 211 is rotatably mounted on the smooth section of the lead screw 21 via a bearing. The first fixed seat 211 is fixed in the axial direction and does not rotate with the lead screw 21. A first movable seat 212 is threadedly engaged on the threaded section of the lead screw 21. The first movable seat 212 reciprocates along the axial direction of the lead screw 21 when the lead screw 21 rotates.

[0028] The first linkage mechanism includes a first link 221 and a second link 222. The first link 221 and the second link 222 are cross-hinged at the middle of the links by a pin, forming a scissor-type linkage structure. One end of the first link 221 is hinged to the first fixed seat 211, and the other end of the first link 221 is hinged to the track travel assembly 24. One end of the second link 222 is hinged to the first movable seat 212, and the other end of the second link 222 is hinged to the track travel assembly 24.

[0029] The second linkage mechanism includes a third link 223 and a fourth link 224. The third link 223 and the fourth link 224 are cross-hinged at the middle of the links by a pin, forming a scissor-type linkage structure. One end of the third link 223 is hinged to the second fixed seat 271, which is fixedly mounted on the drive motor 27, and the other end of the third link 223 is hinged to the other end of the track travel assembly 24. One end of the fourth link 224 is hinged to the second movable seat 272, which is slidably mounted on the drive motor 27, and the other end of the fourth link 224 is hinged to the other end of the track travel assembly 24.

[0030] The second movable seat 272 is connected to the first movable seat 212 via a connecting rod 29. When the lead screw 21 rotates and drives the first movable seat 212 to move axially along the lead screw 21, the first movable seat 212 drives the second movable seat 272 to slide synchronously on the drive motor 27 via the connecting rod 29. When the second movable seat 272 slides, the other end of the track travel assembly 24 is driven to extend or retract synchronously through the cross linkage of the third connecting rod 223 and the fourth connecting rod 224. Through the above-mentioned connecting rod connection, the first linkage mechanism and the second linkage mechanism are linked, so that the two ends of the track travel assembly 24 move synchronously in the axial direction, keeping the track travel assembly 24 stable in posture during extension and retraction, and avoiding skew or jamming caused by unilateral drive.

[0031] The elastic shock absorber assembly 23 is disposed between the lead screw 21 and the linkage mechanism 22 to absorb the radial impact load on the track travel assembly 24 and prevent the impact load from being transmitted to the lead screw 21, causing the lead screw 21 to jam or be damaged. The elastic shock absorber assembly 23 includes an L-shaped nut 231, a stop bolt 232, a first spring 233, and a second spring 234. The L-shaped nut 231 is threaded onto the threaded section of the lead screw 21 and is axially fixed. The L-shaped nut 231 has a sleeve portion and a radial flange portion disposed at one end of the sleeve portion, and its cross-section is L-shaped. The stop bolt 232 passes through the L-shaped nut 231 and is screwed onto the first moving seat 212. The first spring 233 is fitted onto the screw of the stop bolt 232 and is clamped between the L-shaped nut 231 and the first moving seat 212. The second spring 234 is fitted onto the screw of the stop bolt 232 and is clamped between the L-shaped nut 231 and the end cap of the stop bolt 232. Through the cooperation of L-shaped nut 231, plug bolt 232, first spring 233 and second spring 234, a bidirectional elastic floating connection is formed between lead screw 21 and first moving seat 212, so that the first moving seat 212 has an axial elastic floating stroke on lead screw 21.

[0032] When the lead screw 21 rotates, the first movable seat 212 moves along the axial direction of the lead screw 21. Through the cross linkage of the first connecting rod 221 and the second connecting rod 222, it drives the tracked walking assembly 24 to extend outward or retract inward along the radial direction of the pipe, thereby realizing the active adjustment of the robot's outer diameter. When the pipe diameter increases, the lead screw 21 rotates in the forward direction, the first movable seat 212 moves towards the first fixed seat 211, the angle between the first connecting rod 221 and the second connecting rod 222 increases, pushing the tracked walking assembly 24 to extend outward along the radial direction of the pipe, so that the tracked walking assembly 24 fits tightly against the inner wall of the pipe and obtains sufficient walking adhesion. When the pipe diameter decreases, the lead screw 21 rotates in the reverse direction, the first movable seat 212 moves away from the first fixed seat 211, the angle between the first connecting rod 221 and the second connecting rod 222 decreases, pulling the tracked walking assembly 24 to retract inward along the radial direction of the pipe, so that the overall outer diameter of the robot decreases and adapts to small-diameter pipes.

[0033] When the tracked traveling assembly 24 encounters welds, scale, or local protrusions on the inner wall of the pipe and is subjected to radial compression, the radial compression force is transmitted to the first movable seat 212 via the first connecting rod 221 and the second connecting rod 222. When the first movable seat 212 moves towards the L-shaped nut 231, the first spring 233 is compressed, absorbing the radial impact; when the first movable seat 212 moves away from the L-shaped nut 231, the end cap of the plug bolt 232 compresses the second spring 234, absorbing the radial impact. Through the bidirectional elastic buffering of the first spring 233 and the second spring 234, the radial impact load is mechanically decoupled in all directions, effectively preventing the lead screw 21 from jamming and failing due to over-constraint. After the radial compression force is eliminated, the elastic restoring force of the first spring 233 or the second spring 234 drives the first movable seat 212 to reset, allowing the tracked traveling assembly 24 to return to the state of contact with the pipe wall and automatically return to the preset support posture. The entire elastic shock absorption process is achieved entirely through a purely mechanical structure, without the need for any sensors or controllers, thus eliminating the response delay problem of electronic control schemes.

[0034] In this embodiment, three sets of tracked walking components 24 are provided, and the three sets of tracked walking components 24 are evenly arranged circumferentially along the adaptive drive walking section 2. The sleeve 28 of the adaptive drive walking section 2 has three openings corresponding to the tracked walking components 24, through which each tracked walking component 24 extends or retracts. The even circumferential arrangement of the three sets of tracked walking components 24 ensures that the robot obtains uniform radial support force and walking adhesion within the pipe, effectively avoiding instability or jamming caused by uneven loading.

[0035] Reference Figure 3 and Figure 4In this embodiment, the tracked walking assembly 24 includes two opposing support side plates 241, a motor mounting base 242 fixedly disposed between the two support side plates 241, a walking drive motor 243 mounted on the motor mounting base 242, a transmission pulley 244 rotatably mounted on the end of the support side plate 241 via bearings, a transmission belt 245 wound around the transmission pulley 244 and the outer periphery of the support side plate 241, and a bevel gear transmission pair connecting the output shaft of the walking drive motor 243 and the transmission pulley 244. The two support side plates 241 are arranged parallel to each other, serving as the overall mounting frame of the tracked walking assembly 244. A receiving space is formed between the two support side plates 241 for accommodating the walking drive motor 243 and the bevel gear transmission pair, making the overall structure compact. The bevel gear transmission pair includes a first bevel gear 246 and a second bevel gear 247 that mesh perpendicularly with each other. The first bevel gear 246 is coaxially fixed to the output shaft of the walking drive motor 243, and the second bevel gear 247 is coaxially fixed to the central rotating shaft of the transmission pulley 244, forming a bevel gear transmission pair that converts the axial rotational power of the walking drive motor 243 into lateral rotational torque. The transmission pulley 244 is rotatably mounted on the end of the support side plate 241 via bearings. The transmission belt 245 is wound around the outer periphery of the transmission pulley 244 and the support side plate 241, and slides cyclically under the guidance and support of the support side plate 241. The outer wall of the transmission belt 245 is in contact with the inner wall of the pipe to transmit traction force during cyclic sliding, driving the robot to move along the pipe. The outer wall of the transmission belt 245 is provided with anti-slip texture to increase the coefficient of friction with the inner wall of the pipe, further improving the output stability of the traction force.

[0036] Reference Figure 5 In this embodiment, the active steering mechanism is connected between the first walking segment 201 and the second walking segment 202, and is used to drive the first walking segment 201 to actively deflect relative to the second walking segment 202, so that the robot can actively change its direction of travel at complex pipe openings such as T-shaped branch pipes and tees.

[0037] Reference Figures 5 to 9 The active steering mechanism includes a first servo motor 261, a second servo motor 262, a third servo motor 263, and a 90° staggered shaft belt drive mechanism 25. The first servo motor 261 and the third servo motor 263 are respectively located on both sides of the second servo motor 262, and the second servo motor 262 and the third servo motor 263 are fixedly assembled.

[0038] The second servo motor 262 has a first servo plate 2621 and a second servo plate 2622 on both sides along the axial direction of the pipe. The first servo plate 2621 and the second servo plate 2622 are connected by a side plate 263. The first servo plate 2621, the side plate 263 and the second servo plate 2622 form an installation space. The second servo motor 262 is set in this installation space and is fixedly connected to the side plate 263. The output shaft of the second servo motor 262 is arranged vertically and extends through the corresponding through hole of the second servo plate 2622, and is fixedly connected to the drive pulley 251. The second servo plate 2622 is fixedly connected to the third servo motor 263, realizing the fixed assembly of the second servo motor 262 and the third servo motor 263. The fixed assembly of the second servo motor 262 and the third servo motor 263 ensures that they maintain a fixed relative position during operation, avoiding transmission deviation or interference caused by relative movement.

[0039] The 90° staggered shaft belt drive mechanism 25 includes a driving pulley 251, a driven pulley 252, and a drive belt 253. The driving pulley 251 is fixedly connected to the output shaft of the second servo motor 262, and the output shaft of the driven pulley 252 is fixedly connected to the first servo motor 261. The axis of the driven pulley 252 is arranged along the axial direction of the pipe. The drive belt 253 is wound between the driving pulley 251 and the driven pulley 252, and the drive belt 253 is spatially twisted at 90° between the driving pulley 251 and the driven pulley 252.

[0040] Reference Figure 9 A first bearing plate 2521 is arranged on the side of the driven pulley 252 facing the second servo motor 262. The two ends of the first bearing plate 2521 are fixedly connected to the first servo motor plate 2621 and the second servo motor plate 2622, respectively. The first bearing plate 2521 has a boss 25211 extending towards the driven pulley 252. A sleeve 2522 is fitted inside the driven pulley 252. The boss 25211 of the first bearing plate 2521 passes through the sleeve 2522 and is fixed integrally with a third bearing plate 2523. The third bearing plate 2523 is located on the side of the driven pulley 252 facing the first servo motor 261 and is opposite to the first bearing plate 2521. The driven pulley 252 is rotatably fitted onto the outer circumference of the boss 25211 via the sleeve 2522, allowing the driven pulley 252 to rotate freely around the boss 25211. The first bearing plate 2521 serves as a fixed support member, providing rotational support for the driven pulley 252; the sleeve 2522 serves as an inner support structure for the driven pulley 252, isolating the driven pulley 252 from the fixed boss 25211 to ensure smooth rotational movement.

[0041] A second bearing plate 2524 is arranged on the side of the driven pulley 252 facing the first servo motor 261. The second bearing plate 2524 is fitted inside the driven pulley 252 and rotates synchronously with the driven pulley 252. The second bearing plate 2524 is fixedly connected to the first servo motor 261 via a third servo motor plate 2611 and a fourth servo motor plate 2612. The third servo motor plate 2611 and the fourth servo motor plate 2612 are respectively fixedly connected to the two axial ends of the second bearing plate 2524 and extend along the axial direction of the pipe. The first servo motor 261 is fixedly clamped between the third servo motor plate 2611 and the fourth servo motor plate 2612. With the above structure, when the driven pulley 252 rotates, the second bearing plate 2524 fitted inside it drives the third servo motor plate 2611, the fourth servo motor plate 2612, and the first servo motor 261 to rotate as a whole around the axial direction of the pipe. The first bearing plate 2521 provides fixed support for the driven pulley 252, while the second bearing plate 2524 rotates synchronously with the driven pulley 252 and transmits power to the first servo motor 261. The two are separated in motion and do not interfere with each other, ensuring efficient and stable transmission of rotational power.

[0042] Reference Figures 6 to 8 In this embodiment, the active steering mechanism further includes a clamping shaft 254. The two ends of the clamping shaft 254 are fixedly connected to the first servo plate 2621 and the second servo plate 2622, respectively. The clamping shaft 254 is mounted on the transmission belt 253 and is used to tension the transmission belt 253 and maintain the 90° spatial torsion path of the transmission belt 253, ensuring that there is sufficient friction between the transmission belt 253 and the driving pulley 251 and the driven pulley 252, thereby ensuring transmission efficiency and transmission stability.

[0043] When the second servo motor 262 is activated, its output shaft rotates vertically, driving the drive pulley 251 to rotate vertically. The drive pulley 251 drives the driven pulley 252 to rotate axially around the pipe via a transmission belt 253 with a 90° spatial twist. When the driven pulley 252 rotates, it drives the third servo plate 2611, the fourth servo plate 2612, and the first servo motor 261 to rotate axially around the pipe as a whole via a second bearing plate 2524 fitted inside it. The output shaft of the first servo motor 261 changes direction within a 360° range around the pipe axial direction as the first servo motor 261 rotates as a whole. The output shaft of the first servo motor 261 is connected to the first travel section 201, thereby driving the first travel section 201 to deflect in any direction in the horizontal plane.

[0044] The output shaft of the third servo motor 263 is arranged horizontally and perpendicular to the pipe axis. The output shaft of the third servo motor 263 is connected to the second travel section 202 and is used to drive the second travel section 202 to pitch and deflect in the radial plane of the pipe. The output shaft of the first servo motor 261 is also arranged horizontally and perpendicular to the pipe axis. The output shaft of the first servo motor 261 is connected to the first travel section 201 and is used to drive the first travel section 201 to pitch and deflect in the radial plane of the pipe.

[0045] Through the above structure, the second servo motor 262 serves as the power source for active steering. Its rotation around the vertical direction is reversed by the transmission belt 253, which twists 90° in space, driving the driven pulley 252 to rotate around the pipe axis. This, in turn, drives the first servo motor 261 to rotate around the pipe axis as a whole, allowing the output shaft of the first servo motor 261 to change direction arbitrarily within a 360° range. This drives the first walking section 201 to achieve active trajectory changing and steering in any direction in the horizontal plane, enabling the robot to flexibly choose its direction of travel at complex pipe openings such as T-shaped branch pipes and tees. The first servo motor 261 and the third servo motor 263 independently control the pitch and deflection of the first walking section 201 and the second walking section 202 in the radial plane of the pipe, allowing the robot to adjust the posture of the front and rear walking sections in real time according to the pipe slope or obstacle crossing requirements, avoiding jamming caused by pipe undulations or obstacles. The active steering mechanism complements the passive follow-up steering of the spatial linkage universal joint 4, enabling the robot to simultaneously possess passive curve-passing ability and active trajectory-changing steering ability, while also having the advantages of short transmission chain, rapid response, precise control, and compact structure.

[0046] Reference Figure 10 In this embodiment of the application, the spatial link universal joint 4 includes a link base 41, a cross joint 42, and a spatial link 43.

[0047] There are six connecting rod bases 41, three of which are fixed to the end face of one of two adjacent working sections, and the other three are fixed to the end face of the other section. The six connecting rod bases 41 are arranged circumferentially on the end faces, that is, the three connecting rod bases 41 at one end correspond one-to-one with the three connecting rod bases 41 at the other end in the circumferential direction. Each connecting rod base 41 is provided with a hinge hole for hinged connection with the cross joint 42.

[0048] Six cross-joints 42 are provided, each hinged to a connecting rod base 41. Each cross-joint 42 has a first and a second pivot that are perpendicular to each other. The cross-joint 42 is rotatably connected to the corresponding connecting rod base 41 via the first pivot and to the end of the corresponding spatial connecting rod 43 via the second pivot. Through the two perpendicular pivots on the cross-joint 42, each hinge point simultaneously provides two orthogonal degrees of rotational freedom.

[0049] There are three spatial links 43, which are symmetrically distributed at 120° intervals around the pipeline axis. Each spatial link 43 spans between two adjacent working sections. One end of the spatial link 43 is hinged to a cross joint 42 on the end face of one working section, and the other end of the spatial link 43 is hinged to a corresponding cross joint 42 on the end face of the other working section. The three spatial links 43 are staggered in space and do not interfere with each other.

[0050] Each spatial link 43 is bent in the middle to form a avoidance structure. The middle bend design allows the three spatial links 43 to be symmetrically distributed at equal intervals around the pipe axis while being spatially staggered to avoid mutual collision or interference when the joint deflects at a large angle, ensuring that the joint has sufficient deflection stroke.

[0051] The staggered gaps between the three spatial links 43 form a wiring channel, through which control cables and fluid hoses flexibly pass, with allowance for adaptive extension and bending. When the universal joint 4 of the spatial link deflects with the bend, the spatial configuration of the wiring channel changes accordingly. The control cables and fluid hoses adaptively bend or extend within the staggered gaps, utilizing the external open space created by the link bending to achieve dynamic avoidance. This effectively prevents shearing, compression, or excessive stretching of the cables and hoses during large-angle joint movements, ensuring the integrity and reliability of the pipeline in complex bends.

[0052] Through the parallel arrangement of the six cross joints 42 and three spatial links 43, a three-dimensional symmetrically distributed follower parallel linkage mechanism is formed between two adjacent working sections, giving the two working sections three rotational degrees of freedom in three-dimensional space, enabling passive follower deflection in any direction. This three-link parallel configuration allows each spatial link 43 to adaptively elongate or compress according to the curvature of the curve when the robot passes through a curve, automatically guiding the adjacent working sections to deflect along the curve trajectory. Furthermore, the three links constrain each other, ensuring the stability of the posture and the balance of forces between the working sections during the deflection process. Simultaneously, the symmetrical parallel structure significantly improves the torsional stiffness of the spatial link universal joints 4, maintaining reliable connection between the working sections even under large curve curvatures.

[0053] When the robot enters a curve, the front inspection section 1 deflects under the guidance of the curve's wall. This deflection motion is transmitted to the adaptive drive walking section 2 via three spatial links 43 of the spatial linkage universal joint 4, and then to the end cleaning section 3 via the next spatial linkage universal joint 4, causing the three sections to successively deflect along the curve's trajectory. During this process, because the cross joint 42 provides two orthogonal rotational degrees of freedom, the sections can not only swing relative to each other in the horizontal direction, but also pitch and twist around their own axes in the vertical direction, thus achieving complete adaptation to the entire three-dimensional spatial curve of the curve. The entire follow-up steering process is completed automatically by the mechanical structure without the participation of any sensors or controllers, fundamentally eliminating the response delay problem of the electronic control scheme and ensuring the robot's passability and operational continuity in continuous curves.

[0054] Reference Figure 11 In this embodiment, the end cleaning section 3 includes a component sleeve 31, an end cap 32, a tail rod 35, multiple nozzles 33, and a hose 34.

[0055] The component sleeve 31 has a cylindrical structure with an internal space for housing electronic components at the robot's rear end, such as control boards, power modules, and communication modules, providing sealing and protection for these components. An end cap 32 is fixed to the end of the component sleeve 31, sealing the end opening and serving as the mounting base for the tail rod 35. The tail rod 35 is fixed to the center of the end cap 32 and extends outward along the pipe axis. The tail rod 35 has internal channels for the flow of cleaning media.

[0056] Multiple nozzles 33 are arranged in a uniform array along the circumference of the tail rod 35, and the spray center axis of each nozzle 33 is inclined and scattered towards the outer side of the inner wall of the pipe, so that the cleaning medium sprayed by each nozzle 33 forms a continuous coverage in the circumference of the pipe, thereby forming a 360° annular high-pressure cleaning water curtain covering the inner wall of the pipe.

[0057] The hose 34 is installed across the tail end of the end cleaning operation section 3. The output end of the hose 34 is connected to the rear end of the tail rod 35, and the input end of the hose 34 is connected to an external high-pressure cleaning medium source to transport the cleaning medium to the internal flow channel of the tail rod 35, and then spray it out from each nozzle 33.

[0058] When the robot moves to the designated cleaning area, the external high-pressure cleaning medium enters the internal flow channel of the tail rod 35 through the hose 34, and is then sprayed simultaneously onto the inner wall of the pipe by multiple nozzles 33 evenly arrayed around the tail rod 35, forming a 360° annular high-pressure cleaning water curtain covering the inner wall of the pipe. This achieves all-round high-pressure spray cleaning of the inner wall of the pipe, effectively removing dirt, scale and residue from the inner wall of the pipe, and completing the cleaning and maintenance work of the inner wall of the pipe.

[0059] The above description is merely a preferred embodiment of the present invention and does not limit the scope of patent protection of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are all covered within the scope of patent protection of the present invention.

Claims

1. A robot for inspecting the inner wall of a pipeline, characterized in that, It includes a front-end inspection operation section (1), an adaptive drive walking section (2), and an end cleaning operation section (3). The front-end inspection operation section (1) and the adaptive drive walking section (2), as well as the adaptive drive walking section (2) and the end cleaning operation section (3), are sequentially connected by a spatial linkage universal joint (4). The end of the front-end inspection section (1) is equipped with a vision inspection unit (11) and a clamping mechanism (12). The adaptive drive walking segment (2) includes a first walking segment (201), a second walking segment (202), and an active steering mechanism connected between the first walking segment (201) and the second walking segment (202). The first walking segment (201) and the second walking segment (202) each independently include a lead screw (21), a linkage mechanism (22), a drive motor (27), an elastic shock absorber assembly (23), and a track walking assembly (24). The lead screw (21) is connected to the drive motor (27). One end of the linkage mechanism (22) is connected to the lead screw (21), and the other end is connected to the track walking assembly (24). The elastic shock absorber assembly (23) is disposed between the lead screw (21) and the linkage mechanism (22). When the lead screw (21) rotates, it drives the linkage mechanism (22) to expand or retract, thereby causing the track walking assembly (24) to extend outward or retract inward along the radial direction of the pipeline. The active steering mechanism is connected between the first walking section (201) and the second walking section (202) and is used to drive the first walking section (201) to actively deflect relative to the second walking section (202).

2. The robot for inspecting the inner wall of a pipeline according to claim 1, characterized in that, The spatial link universal joint (4) includes a link base (41), a cross joint (42), and a spatial link (43). The connecting rod base (41) is provided with multiple and fixed to the end face of each working section. The cross joint (42) is hinged to each of the connecting rod bases (41). The spatial connecting rod (43) spans between two adjacent working sections and its two ends are respectively hinged to the cross joint (42) on the corresponding side.

3. The robot for inspecting the inner wall of a pipeline according to claim 2, characterized in that, The cross joint (42) has a first rotating shaft and a second rotating shaft that are perpendicular to each other. The cross joint (42) is rotatably connected to the corresponding connecting rod base (41) through the first rotating shaft, and is rotatably connected to the end of the corresponding spatial connecting rod (43) through the second rotating shaft. The number of the three spatial links (43) is three. The three spatial links (43) are symmetrically distributed at 120° intervals around the pipeline axis and do not interfere with each other in space.

4. The robot for inspecting the inner wall of a pipeline according to claim 1, characterized in that, The active steering mechanism includes a first servo motor (261), a second servo motor (262), a third servo motor (263), and a 90° staggered shaft belt drive mechanism (25). The first servo (261) and the third servo (263) are respectively disposed on both sides of the second servo (262). The second servo (262) and the third servo (263) are fixedly assembled. The second servo (262) is connected to the first servo (261) through the 90° staggered shaft belt transmission mechanism (25).

5. The robot for inspecting the inner wall of a pipeline according to claim 4, characterized in that, The 90° staggered shaft belt drive mechanism (25) includes a driving pulley (251), a driven pulley (252), and a drive belt (253). The output shaft of the second servo motor (262) is arranged vertically and connected to the driving pulley (251). The driving pulley (251) is connected to the driven pulley (252) through the transmission belt (253) which is twisted at 90°. The output shaft of the driven pulley (252) is fixedly connected to the first servo motor (261). The axis of the driven pulley (252) is arranged along the axial direction of the pipe. The second servo motor (262) drives the driving pulley (251) to rotate in the vertical direction. The driving pulley (251) drives the driven pulley (252) to rotate in the pipe axis via the transmission belt (253). The driven pulley (252) drives the first servo motor (261) to rotate in the pipe axis as a whole. The output shaft of the first servo motor (261) changes direction within a 360° range around the pipe axis as the first servo motor (261) rotates in the whole.

6. The robot for inspecting the inner wall of a pipeline according to claim 4, characterized in that, The active steering mechanism further includes a pressure shaft (254), which is mounted on the transmission belt (253) to tension the transmission belt (253) and maintain the spatial torsional path of the transmission belt (253).

7. The robot for inspecting the inner wall of a pipeline according to claim 1, characterized in that, The tracked walking assembly (24) is provided in three sets; The three sets of tracked walking components (24) are evenly arranged around the circumference of the adaptive drive walking section (2). The adaptive drive walking section (2) has three openings that correspond one-to-one with the tracked walking components (24). Each tracked walking component (24) extends or retracts through the corresponding opening.

8. The robot for inspecting the inner wall of a pipeline according to claim 1, characterized in that, The elastic shock absorber assembly (23) includes a nut (231), a bolt (232), a first spring (233), and a second spring (234); The nut (231) is threaded onto the threaded section of the lead screw (21) and its axial position is fixed. The bolt (232) passes through the nut (231) and is screwed onto the first movable seat (212) that is slidably mounted on the lead screw (21). The first spring (233) is fitted onto the threaded section of the bolt (232) and is clamped between the nut (231) and the first movable seat (212). The second spring (234) is fitted onto the threaded section of the bolt (232) and is clamped between the nut (231) and the end cap of the bolt (232). The linkage mechanism (22) includes a first link (221) and a second link (222). The first link (221) and the second link (222) are cross-hinged at the middle of the link by a pin to form a scissor-type linkage structure. One end of the first connecting rod (221) is hinged to a first fixed seat (211) fixedly mounted on the lead screw (21), and the other end of the first connecting rod (221) is hinged to the track walking assembly (24); One end of the second link (222) is hinged to the first movable seat (212) that is slidably mounted on the lead screw (21), and the other end of the second link (222) is hinged to the track walking assembly (24).

9. The robot for inspecting the inner wall of a pipeline according to claim 1, characterized in that, The visual inspection unit (11) includes an industrial camera (111) and a pair of LED fill lights (112). The industrial camera (111) is located at the center of the end face of the front-end inspection section (1), and a pair of LED fill lights (112) are horizontally and symmetrically fixed on the left and right sides of the industrial camera (111). The clamping mechanism (12) is located below the vision detection unit (11). The clamping mechanism (12) includes: a working servo motor (121), a gear transmission mechanism (122), and double-sided grippers (123). The output shaft of the working servo motor (121) is connected to the gear transmission mechanism (122), and the gear transmission mechanism (122) is connected to the double-sided grippers (123). The working servo motor (121) drives the double-sided grippers (123) to open and close synchronously through the gear transmission mechanism (122).

10. The robot for inspecting the inner wall of a pipeline according to claim 1, characterized in that, The end cleaning section (3) includes a component sleeve (31), an end cap (32) fixed to the end of the component sleeve (31), a tail rod (35) fixed to the center of the end cap (32) and extending outward, a plurality of nozzles (33) arranged circumferentially along the tail rod (35), and a hose (34) for delivering fluid medium to the nozzles (33). The hose (34) is connected to the internal flow channel of the tail rod (35), and the nozzle (33) is connected to the internal flow channel of the tail rod (35). The spray center axis of the multiple nozzles (33) is inclined and scattered towards the outside of the inner wall of the pipe to form an annular high-pressure cleaning water curtain covering the inner circumference of the pipe.

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