Dual-state special pipeline inspection robot based on line-driven metamorphosis and its control method

Abstract

The present invention discloses a dual-state special pipeline inspection robot based on a wire-driven metamorphosis and a control method thereof, relating to the field of robotics. The robot comprises an upper robot unit and a lower robot unit that climb walls by adsorption, as well as a gear train structure, pulleys, and cables. The gear train structure is mounted at the bottom center of the frame of the upper robot unit, with each pulley rotatably mounted on the inner side of each leg structure. Cables are tensioned and wound around the pulleys, with their bottom and top ends respectively connected and fixed to the frames of the lower and upper robot units. The present invention comprises two single-unit robots connected by cables. The two robots can be separated into two parts to form a flexible frame structure with a yielding function, using roller-type forward motion and achieving a high moving speed; or they can be combined into a whole to form a monolithic structure with higher structural strength, using a step-type forward motion and achieving higher passability. The robot is particularly suitable for pipeline operations in complex environments.

Description

Technical Field

[0001] The present invention relates to the field of robot technology, and in particular to a line-driven metamorphic dual-state robot for pipeline detection and a control method thereof. Background Art

[0002] A pipeline robot is an integrated mechanical, electrical, and hydraulic system that can autonomously navigate the interior or exterior of small pipelines. Carrying one or more sensors and operating mechanisms, it performs a range of pipeline operations under remote control or computerized control. Pipeline robots replace human labor in high-risk or repetitive tasks, offering advantages such as rapid movement, flexible operation, accurate operation, and low cost.

[0003] Through prior art search, the following known technical solutions exist:

[0004] Existing technology 1: "Structural design and analysis of adaptive pipe diameter full-drive pipeline robot"

[0005] (Zheng Likang, Feng Yongli, Li Zhanxian, et al. Structural design and analysis of adaptive pipe diameter full-drive pipeline robot[J]. Mechanical Transmission, 2023, 47(05): 67-73. DOI: 10.16578 / j.issn.1004.2539.2023.05.012.)

[0006] Prior Art 1 discloses a pipeline robot. Except for the wheels and various standard components, all other components are made of 6061 aluminum alloy, with an overall structural mass of approximately 7 kg. The robot's support is hinged to the main body via two parallel support rods, ensuring that the upper support rod always remains parallel to the main body during lifting and lowering. The other support rod is hinged to a sliding sleeve mounted on the main body and a closer parallel support rod. Tension springs are installed on both sides of the support rods to accommodate different pipe diameters.

[0007] However, the robot of the prior art 1 has a heavy overall mass and a large body rigidity. Therefore, when the robot moves, it has limited obstacle avoidance capabilities when facing relatively complex structures inside the tube, which greatly restricts its application.

[0008] Existing Technology 2: "Structural Design and Motion Analysis of Adaptive Active Obstacle Avoidance Pipeline Robot"

[0009] (Huang Mengyuan, Zhu Zichen, Zeng Xianyong. Structural design and motion analysis of adaptive active obstacle avoidance pipeline robot[J]. Journal of Southwest Normal University (Natural Science Edition), 2023, 48(06):12-24. DOI:10.13718 / j.cnki.xsxb.2023.06.002.)

[0010] The robot disclosed in Prior Art 2 utilizes a dual-drive-wheel and dual-steering-wheel design. Its main structure consists of three parts: a central module and two flanking motion modules. The central module is equipped with a symmetrical ball screw, two splined rails, a screw motor, and a module deflection motor and transmission mechanism. The motion modules are equipped with a steering wheel and a drive wheel, as well as a steering servo motor and a drive motor. The central module and the two motion modules are connected by a scissor-type arm with a diameter-reducing mechanism. The robot is capable of wall-crushing travel at a certain height within a circular pipe. The robot can enter the circular pipe through a square connecting manhole by deflecting the motion modules. Combined with the steering wheels, the robot can rotate along the pipe's circumference, achieving obstacle avoidance.

[0011] However, due to the limitations of its wheeled structure, the robot of the existing technology 2 cannot cope with more complex situations and can only move and avoid obstacles in the lower half of the pipeline.

[0012] Existing Technology 3: Simulation Analysis and Optimization Design of the Variable Diameter Mechanism of a Crawler Pipeline Robot

[0013] (Cui Xianggui, Zhang Jizhong, Jiang Jinhua. Simulation analysis and optimization design of the diameter-changing mechanism of crawler pipeline robot[J]. Journal of Qingdao University (Natural Science Edition), 2023, 36(02):79-83.)

[0014] Prior art 3 discloses a tracked pipeline robot with adaptive and active adaptive functions. The robot is equipped with three track wheels. When working, the three track wheels are pressed against the inner wall of the pipeline by the holding torque of the stepper motor to generate sufficiently large adhesion, and finally generate friction consistent with the movement direction of the robot and drive the robot to move; each track wheel is equipped with a drive motor, and steering and other functions are achieved by adjusting the speed of the drive motor; the front end of the robot is equipped with a detection module for recording the actual situation of the inner wall of the pipeline, and after transmitting it to the upper computer, the pipeline defects can be judged by image recognition and processing technology; a certain expansion interface is reserved at the rear end, and a corresponding obstacle cleaning device or spraying device is equipped to complete specific tasks.

[0015] However, the robot of the prior art 3 has a single variable diameter structure and uses tracks as a walking method, which leads to a lack of flexibility in its movement and some deficiencies in cornering, making it unable to flexibly complete the operation purpose of cornering and overcoming obstacles in complex environments.

[0016] Through the above search, it is found that the above technical solutions do not affect the novelty of the present invention; and the combination of the above prior arts does not destroy the creativity of the present invention. Summary of the Invention

[0017] In order to avoid the above-mentioned deficiencies in the prior art, the present invention provides a dual-state special pipeline inspection robot based on line-driven metamorphosis.

[0018] The present invention adopts the following technical solution to solve the technical problem: a dual-state special pipeline inspection robot based on a wire-driven metamorphosis, provided with a robot unit that climbs walls and walks in an adsorption manner, the robot unit comprising a frame and a leg-foot structure mounted on the frame, the front end structure of the leg-foot structure outputting forward and backward swinging and inward and outward movement to the terminal structure, utilizing the adsorption force between the adsorption wheel of the terminal structure and the pipeline to achieve support and walking of the robot, the number of the robot units being two, one of the two robot units being located at the top and serving as the upper robot unit, and the other being located at the bottom and serving as the lower robot unit;

[0019] It also includes gear train structures, pulleys and cables;

[0020] A gear train structure is installed at the bottom center of the frame in the upper robot unit;

[0021] The pulleys and the cables are arranged in one-to-one correspondence with the leg and foot structures in the upper robot unit, and the pulleys are evenly distributed on the inner side of each leg and foot structure in the circumferential direction of the gear train structure, and are rotatably mounted and connected to the frame of the upper robot unit;

[0022] The cable is tensioned and wound around the corresponding pulley, and its bottom end and top end are respectively connected and fixed to the frames of the lower robot unit and the upper robot unit, with the connection points located on the inner sides of the corresponding leg and foot structures;

[0023] The gear train structure outputs a motion driving each of the pulleys to rotate synchronously, so that the cable is wound around the corresponding pulley one by one to shorten the length of the cable between the lower robot unit and the upper robot unit, or the cable is detached from the corresponding pulley one by one to lengthen the length of the cable between the lower robot unit and the upper robot unit;

[0024] When the top end and the bottom end of the cable are vertically opposite each other, the leg and foot structures of the upper robot unit and the lower robot unit are arranged in a staggered manner along the circumferential direction in a top view projection plane.

[0025] Furthermore, the leg and foot structure includes a front and rear swing drive, a thigh, an adduction and abduction drive, a calf structure and the suction wheel;

[0026] The thigh is located outside the corresponding frame, and its inner end is rotatably connected to the frame, forming a forward and backward swing pair between the thigh to support the thigh to swing forward or backward with its inner end as the swing axis;

[0027] The front-to-back swing driving machine serves as the front end structure of the leg-foot structure, with its fixed end fixedly mounted on the frame and its output end rotatably connected to the inner end of the thigh, driving the thigh to swing forward or backward under the support of the front-to-back swing rotation pair;

[0028] The fixed end of the adduction and abduction driving machine is fixed to the outer end of the thigh, and the output end is connected to the inner end of the calf structure, driving the adsorption wheel connected to the outer end of the calf structure to adduct or abduct relative to the thigh.

[0029] Furthermore, the calf structure includes an active rod, a driven rod and a foot claw, which together with the thigh form a double crank four-bar structure of unequal length;

[0030] The inner end of the active rod serves as the inner end of the calf structure and is installed and connected to the output end of the adduction and abduction driving machine, and its outer end is hinged to the middle part of the paw; the inner and outer ends of the driven rod are hinged to the outer end of the thigh and the inner end of the paw respectively; the adsorption wheel is rotatably installed to the outer end of the paw and is axially connected to the single-foot driving machine.

[0031] Furthermore, the adsorption wheel is a Mecanum wheel.

[0032] Furthermore, the gear train structure includes a center gear, a bevel gear and a transmission shaft;

[0033] The center wheel is located at the bottom center of the frame and is equipped with a center wheel driving machine that drives its own fixed axis rotation; the bevel gear and the transmission shaft are arranged in a one-to-one correspondence with the pulley; the pulley is mounted and fixed on the transmission shaft, and is rotatably connected to the frame through the transmission shaft, and the bevel gear meshing with the center wheel is mounted and fixed on one end of the transmission shaft facing the center wheel.

[0034] Furthermore, the bottom of the frame in the upper robot unit and the top of the frame in the lower robot unit are in a mortise and tenon structure that fits together.

[0035] Furthermore, the frame is a regular triangular prism-like structure, and three leg-foot structures are evenly distributed around the robot body.

[0036] Furthermore, an interface is provided on the top of the frame of the upper single robot.

[0037] Furthermore, the inner end of the foot paw is a square U-shaped structure with an opening facing inward, and an anti-slip pad is fixed to the end of the square U-shaped structure;

[0038] The foot claw is a hollow structure, and a storage cavity for storing tools is formed inside the foot claw.

[0039] A control method for a dual-state special pipeline inspection robot based on a wire-driven metamorphosis is provided, wherein the dual-state special pipeline inspection robot based on a wire-driven metamorphosis is used to perform internal operations in a pipeline, comprising the following steps:

[0040] The first step is to select leg and foot structures of appropriate size based on the operating pipeline environment and install them on the frames of the upper and lower robots. Then, based on the type of operation, select appropriate terrain exploration equipment and operating equipment and install them on the top of the frame of the upper robot through the interface.

[0041] In the second step, the pipeline inspection robot enters the pipeline in a detached configuration with the upper and lower robot units separated and connected only by a cable. Initially, the geometric center axes of the upper and lower robot units coincide, and the leg and foot structures of the upper and lower robot units correspond one-to-one in the top projection plane.

[0042] The upper robot and the lower robot adjust their postures respectively:

[0043] Each adduction and abduction drive mechanism drives the Mecanum wheel to abduct relative to the thigh via the thigh and calf structures, adjusting the contact between the Mecanum wheel and the inner wall of the pipe so that the upper robot unit and the lower robot unit are firmly supported inside the pipe;

[0044] In the third step, the monopods in the upper robot drive the Mecanum wheels in a coordinated manner, causing the upper robot to move forward a certain distance, with the upper robot in front and the lower robot behind. Subsequently, the monopods in the upper and lower robots drive the Mecanum wheels in a coordinated manner, allowing the pipeline inspection robot to move forward in a wheeled manner within the pipeline, with the upper robot in front and the lower robot behind.

[0045] The fourth step is to use terrain survey equipment to survey the terrain ahead of the pipeline:

[0046] If the terrain ahead is impassable, or the pipeline inspection robot has reached the end of the operation, the pipeline inspection robot will retreat outside the pipeline and end the operation;

[0047] If there is a curved pipe in front, proceed to step 5;

[0048] If the front is a straight pipe, proceed to step 6;

[0049] In the fifth step, the Mecanum wheels work together to drive at least one of the upper and lower robots to rotate around their own geometric center axis, so that the relative rotation angle between the two is 180 degrees. At this point, the upper and lower robots form a three-degree-of-freedom spherical joint structure, allowing the upper and lower robots to rotate at their connection and move forward in a wheeled manner.

[0050] When passing through the bend, the terrain survey equipment keeps surveying the terrain ahead in the pipeline:

[0051] If there is an obstacle with a cross-sectional area S > S0 ahead, the pipeline inspection robot retreats outside the pipeline and ends the operation;

[0052] If there is an obstacle ahead and the cross-sectional area S of the obstacle is < S0, in the upper single-body robot, each Mecanum wheel acts cooperatively to make the upper single-body robot rotate around its own geometric center axis until each Mecanum wheel bypasses the obstacle. During this process, in the lower single-body robot, each Mecanum wheel acts cooperatively to make the lower single-body robot rotate adaptively around its own geometric center axis to maintain a three-degree-of-freedom spherical joint structure formed by the upper single-body robot and the lower single-body robot;

[0053] Subsequently, the lower single-body robot follows the movement of the upper single-body robot. Each Mecanum wheel in the lower single-body robot acts cooperatively to make the lower single-body robot rotate around its own geometric center axis until each Mecanum wheel bypasses the obstacle. During this process, in the upper single-body robot, each Mecanum wheel acts cooperatively to make the upper single-body robot rotate adaptively around its own geometric center axis to maintain a three-degree-of-freedom spherical joint structure formed by the upper single-body robot and the lower single-body robot;

[0054] After that, the pipeline inspection robot moves forward in a wheeled manner in the pipeline with the upper single-body robot in front and the lower single-body robot behind, and repeats the fourth step;

[0055] Where S0 is the preset allowable cross-sectional area of the obstacle;

[0056] If there is no obstacle ahead, the pipeline robot maintains its attitude and moves forward in a wheeled manner until it passes through the bend. Subsequently, at least one of the upper single-body robot and the lower single-body robot rotates and resets around its own geometric center axis, and repeats the fourth step;

[0057] Step 6, further judge the terrain ahead:

[0058] If there is no obstacle ahead, the pipeline inspection robot moves forward in a wheeled manner in the pipeline with the upper single-body robot in front and the lower single-body robot behind, and repeats the fourth step;

[0059] If there is an obstacle ahead and the cross-sectional area S of the obstacle is < S0, in the upper single-body robot, each Mecanum wheel acts cooperatively to make the upper single-body robot rotate around its own geometric center axis until each Mecanum wheel bypasses the obstacle;

[0060] Subsequently, the lower single-body robot follows the movement of the upper single-body robot. Each Mecanum wheel in the lower single-body robot acts cooperatively to make the lower single-body robot rotate around its own geometric center axis until each Mecanum wheel bypasses the obstacle;

[0061] After that, the pipeline inspection robot moves forward in a wheeled manner in the pipeline with the upper single-body robot in front and the lower single-body robot behind, and repeats the fourth step;

[0062] If there is an obstacle ahead and the cross-sectional area of ​​the obstacle S>S0, or the diameter of the pipe ahead changes so much that the pipeline inspection robot cannot pass through in a separated form, the gear system structure will synchronously reel the cables back onto the corresponding pulleys, so that the upper robot unit and the lower robot unit are integrated into a whole.

[0063] Subsequently, the leg and foot structures of the pipeline inspection robot are divided into two groups as symmetrically as possible. The two groups of leg and foot structures take turns to lift and lower. When each group of leg and foot structures is lifted for the first time, the adduction and abduction drive motor in each leg and foot structure drives the Mecanum wheel to lift up and away from the inner wall of the pipeline via the calf structure, so that the inner end of the foot claw rotates to the side close to the inner wall of the pipeline. Then the leg and foot structure falls, with the inner end of the foot claw as the structure in contact with the inner wall of the pipeline, and switches to a step-like forward movement.

[0064] The pipeline inspection robot moves forward in steps through obstacles or pipe sections with a sharp change in diameter, and performs the fourth step again.

[0065] The present invention provides a dual-state special pipeline inspection robot based on line-driven metamorphosis, which has the following beneficial effects:

[0066] The present invention is provided with two single robots connected by cables, which can be separated into two parts to form a flexible frame structure with a giving way function, adopting a roller-type forward movement and having a higher moving speed; or they can be combined into a whole to form an integral structure with higher structural strength, adopting a step-type forward movement and having higher passability, and are particularly suitable for pipeline operations in complex environments; the multi-leg structure of the present invention enables the robot to maintain multiple adsorption wheels gripping the wall during movement, thereby ensuring the stability of the robot's movement and better adapting to complex wall environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 It is a structural schematic diagram of the present invention;

[0068] Figure 2 It is a structural schematic diagram of the leg and foot structure of the present invention;

[0069] Figure 3 This is a schematic diagram of the bottom view of the robot unit of the present invention.

[0070] In the picture:

[0071] 1. Frame, 9. Lower leg structure, 10. Active rod, 11. Driven rod, 13. Adduction and abduction drive mechanism, 14. Forward and backward swing drive mechanism, 15. Cable, 16. Paw, 17. Thigh, 18. Gear train structure, 19. Pulley, 20. Interface. DETAILED DESCRIPTION

[0072] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0073] A dual-state special pipeline inspection robot based on line-driven metamorphosis, such as Figures 1 to 3 As shown, its structural relationship is as follows: a robot unit for climbing walls and walking in the form of adsorption is provided, the robot unit comprising a frame 1 and a leg-foot structure mounted on the frame 1, the front end structure of the leg-foot structure outputs forward and backward swinging and inward and outward movement to the end structure, and the robot is supported and walked by the adsorption force between the adsorption wheel 12 as the end structure and the pipeline. There are two robot units, one of which is located at the top and serves as the upper robot unit, and the other is located at the bottom and serves as the lower robot unit;

[0074] It also includes a gear train structure 18, a pulley 19 and a cable 15;

[0075] A gear train structure 18 is installed at the bottom center of the frame 1 in the upper robot unit;

[0076] The pulleys 19 and cables 15 are arranged one-to-one with the leg and foot structures in the upper robot unit. The pulleys 19 are evenly distributed on the inner side of each leg and foot structure in the circumferential direction of the gear train structure 18 and are rotatably mounted and connected to the frame 1 of the upper robot unit.

[0077] The cable 15 is tensioned and wound around the corresponding pulley 19, and its bottom end and top end are respectively connected and fixed to the frame 1 of the lower robot unit and the upper robot unit, and the connection points are located on the inner side of the corresponding leg and foot structure;

[0078] The output of the gear train structure 18 drives the pulleys 19 to rotate synchronously, so that the cable 15 is wound around the corresponding pulley 19 one by one to shorten the length of the cable 15 between the lower robot unit and the upper robot unit, or the cable 15 is unwound from the corresponding pulley 19 one by one to lengthen the length of the cable 15 between the lower robot unit and the upper robot unit;

[0079] When the top and bottom ends of the cable 15 are vertically aligned, the leg and foot structures of the upper robot unit and the lower robot unit are arranged in a staggered manner along the circumferential direction in a top view projection plane.

[0080] The upper robot unit and the lower robot unit are connected by a cable 15. During the operation of the pipeline inspection robot, the distance between the upper robot unit and the lower robot unit can be adjusted by retracting and extending the cable 15 according to the actual working conditions, thereby realizing the transformation of the overall shape of the pipeline inspection robot and maintaining the stable working state of the pipeline inspection machine.

[0081] In actual configuration, the rope 15 is preferably a steel wire.

[0082] Preferably, the leg and foot structure includes a front and rear swing drive 14, a thigh 17, an adduction and abduction drive 13, a calf structure 9 and a suction wheel 12;

[0083] The thigh 17 is located outside the corresponding frame 1, and its inner end is rotatably connected to the frame 1, forming a forward and backward swing pair between the thigh and the frame 1, which supports the thigh to swing forward or backward with its inner end as the swing axis;

[0084] The front and rear swing drive 14 serves as the front end structure of the leg and foot structure. Its fixed end is fixed to the frame 1, and its output end is rotatably connected to the inner end of the thigh, driving the thigh to swing forward or backward under the support of the front and rear swing pair.

[0085] The fixed end of the adduction and abduction driving machine 13 is installed and fixed to the outer end of the thigh 17, and its output end is installed and connected to the inner end of the calf structure 9, driving the adsorption wheel 12 installed and connected to the outer end of the calf structure 9 to adduct or abduct relative to the thigh 17.

[0086] The leg and foot structure is preferably installed on the frame 1 in a detachable connection manner. During actual setting, the leg and foot structure of appropriate size can be replaced according to the environment to further improve the adaptability of the pipeline inspection robot to the working environment.

[0087] Preferably, the calf structure 9 includes an active rod 10, a driven rod 11 and a foot claw 16, which together with the thigh 17 form an unequal length double crank four-bar structure;

[0088] The inner end of the active rod 10 serves as the inner end of the calf structure 9 and is installed and connected to the output end of the adduction and abduction driving machine 13, and its outer end is hinged to the middle part of the claw 16; the inner and outer ends of the driven rod 11 are hinged to the outer end of the thigh 17 and the inner end of the claw 16 respectively; the suction wheel 12 is rotatably installed to the outer end of the claw 16 and is axially connected to the single-foot driving machine.

[0089] In actual configuration, the single-leg drive motor is preferably a DC motor.

[0090] Preferably, the adsorption wheel 12 is a Mecanum wheel.

[0091] Preferably, the gear train structure 18 includes a center gear, a bevel gear and a transmission shaft;

[0092] The center wheel is located at the bottom center of the frame 1 and is equipped with a center wheel driving machine that drives its own fixed axis rotation; the bevel gear and the transmission shaft are arranged in a one-to-one correspondence with the pulley 19; the pulley 19 is installed and fixed to the transmission shaft, and is rotatably connected to the frame 1 through the transmission shaft. A bevel gear meshing with the center wheel is installed and fixed on one end of the transmission shaft facing the center wheel.

[0093] Preferably, the bottom of the frame 1 in the upper robot unit and the top of the frame 1 in the lower robot unit are in a mortise and tenon structure that fits together.

[0094] Preferably, the frame 1 is a regular triangular prism-like structure, and three leg-foot structures are evenly distributed around the robot body.

[0095] Preferably, an interface 20 is provided on the top of the frame 1 of the upper single robot.

[0096] The interface is used to install detection equipment such as radar and cameras, or other operating equipment such as spraying devices, so as to use the pipeline inspection robot to realize pipeline inspection, spraying and other operations as needed.

[0097] Preferably, the inner end of the foot claw 16 is a square U-shaped structure with the opening facing inward, and an anti-slip pad is fixed to the end of the square U-shaped structure;

[0098] The foot claw 16 is hollow, and a storage cavity for storing tools is formed therein.

[0099] A control method for a dual-state special pipeline inspection robot based on a wire-driven metamorphosis is provided, wherein the dual-state special pipeline inspection robot based on a wire-driven metamorphosis is used to perform internal operations in a pipeline, comprising the following steps:

[0100] The first step is to select leg and foot structures of appropriate size based on the operating pipeline environment and install them on the frames 1 of the upper and lower robots. Then, based on the type of operation, select appropriate terrain exploration equipment and operating equipment and install them on the top of the frame 1 of the upper robot through the interface 20.

[0101] In actual settings, the terrain exploration equipment is preferably a camera or a lidar, and the operating equipment can be a pipeline spraying equipment, a pipeline cleaning equipment, etc.

[0102] In the second step, the pipeline inspection robot enters the pipeline in a separated configuration, with the upper robot unit and the lower robot unit separated and connected only by the cable 15. In the initial state, the geometric center axes of the upper robot unit and the lower robot unit coincide, and the leg and foot structures of the upper robot unit and the lower robot unit correspond one-to-one in the top projection plane.

[0103] The upper robot and the lower robot adjust their postures respectively:

[0104] Each adduction and abduction drive 13 drives the Mecanum wheels to abduct relative to the thigh 17 through the thigh 17 and the shank structure 9, adjusting the contact between the Mecanum wheels and the inner wall of the pipe so that the upper and lower robot units are firmly supported inside the pipe.

[0105] In the third step, the monopods in the upper robot drive the Mecanum wheels in a coordinated manner, causing the upper robot to move forward a certain distance, with the upper robot in front and the lower robot behind. Subsequently, the monopods in the upper and lower robots drive the Mecanum wheels in a coordinated manner, allowing the pipeline inspection robot to move forward in a wheeled manner within the pipeline, with the upper robot in front and the lower robot behind.

[0106] When the pipeline inspection robot moves forward by relying on Mecanum wheels, it has a high moving speed, which effectively improves the overall operating efficiency of the pipeline inspection robot;

[0107] The fourth step is to use terrain survey equipment to survey the terrain ahead of the pipeline:

[0108] If the terrain ahead is impassable,

[0109] If the inside of the pipeline is blocked or the gap between the obstacle and the pipe wall is not large enough for the pipeline inspection robot to pass through,

[0110] Or if the pipeline inspection robot has reached the end position of the operation, the pipeline inspection robot will retreat outside the pipeline and end the operation;

[0111] In actual settings, the terrain survey equipment can be a camera, and the staff can determine whether the front of the pipeline is an impassable terrain based on the image information collected and sent back by the camera;

[0112] If there is a curved pipe in front, proceed to step 5;

[0113] If the front is a straight pipe, proceed to step 6;

[0114] In the fifth step, the Mecanum wheels work together to drive at least one of the upper and lower robots to rotate around their own geometric center axis, so that the relative rotation angle between the two is 180 degrees. At this point, the upper and lower robots form a three-degree-of-freedom spherical joint structure, allowing the upper and lower robots to rotate at their connection and move forward in a wheeled manner.

[0115] For the specific method of the upper single - body robot and the lower single - body robot passing through the bend, refer to "Quaternion Joint: Dexterous 3 - DOF Joint Representing Quaternion Motion for High - Speed Safe Interaction," Y. -J. Kim, J. -I. Kim and W. Jang, 2018 IEEE / RSJ International Conference on Intelligent Robots and Systems (IROS), Madrid, Spain, 2018, pp.935 - 942, doi: 10.1109 / IROS.2018.8594301. keywords: {Wires; Wrist; Manipulators; Quaternions; Pulleys; Kinematics}

[0116] During the process of passing through the bend, the terrain exploration device keeps surveying the terrain in front inside the pipeline:

[0117] If there is an obstacle with a cross - sectional area exceeding S > S0 ahead, the pipeline inspection robot retreats outside the pipeline and ends the operation;

[0118] If there is an obstacle ahead and the cross - sectional area of the obstacle S < S0, in the upper single - body robot, each Mecanum wheel acts in coordination to make the upper single - body robot rotate around its own geometric central axis until each Mecanum wheel bypasses the obstacle. During this process, in the lower single - body robot, each Mecanum wheel acts in coordination to make the lower single - body robot adaptively rotate around its own geometric central axis to maintain a three - degree - of - freedom spherical - joint - like structure formed by the upper single - body robot and the lower single - body robot;

[0119] Subsequently, the lower single - body robot follows the movement of the upper single - body robot. Each Mecanum wheel in the lower single - body robot acts in coordination to make the lower single - body robot rotate around its own geometric central axis until each Mecanum wheel bypasses the obstacle. During this process, in the upper single - body robot, each Mecanum wheel acts in coordination to make the upper single - body robot adaptively rotate around its own geometric central axis to maintain a three - degree - of - freedom spherical - joint - like structure formed by the upper single - body robot and the lower single - body robot;

[0120] After that, the pipeline inspection robot moves forward in a wheeled manner inside the pipeline with the upper single - body robot in front and the lower single - body robot behind, and repeats the fourth step;

[0121] Where S0 is the preset allowable cross - sectional area of the obstacle;

[0122] The theoretical limit value of the allowable obstacle cross-sectional area S0 has a relationship with the number of leg and foot structures of the upper robot unit or the lower robot unit without considering the structural collision volume as S0 = 1 / the number of leg and foot structures; in actual setting, when the specific shape and size of the pipeline inspection robot are determined, the value of S0 can be obtained through the threshold detection method, that is, by identifying the mutation of pixel intensity in the image to locate the boundary of the obstacle and thus obtain the area of the obstacle, and a proper margin should be left;

[0123] If there is no obstacle ahead, the pipeline robot maintains its attitude and moves forward in a wheeled manner until it passes through the bend. Subsequently, at least one of the upper robot unit and the lower robot unit rotates and resets around its own geometric central axis, and then the fourth step is performed again;

[0124] The sixth step is to further judge the terrain ahead:

[0125] If there is no obstacle ahead, the pipeline inspection robot maintains the state with the upper robot unit in the front and the lower robot unit in the back and moves forward in a wheeled manner inside the pipeline, and then the fourth step is performed again;

[0126] If there is an obstacle ahead and the cross-sectional area S of the obstacle is less than S0, in the upper robot unit, each Mecanum wheel acts in coordination to make the upper robot unit rotate around its own geometric central axis until each Mecanum wheel bypasses the obstacle;

[0127] Subsequently, the lower robot unit follows the action of the upper robot unit. Each Mecanum wheel in the lower robot unit acts in coordination to make the lower robot unit rotate around its own geometric central axis until each Mecanum wheel bypasses the obstacle;

[0128] After that, the pipeline inspection robot moves forward in a wheeled manner inside the pipeline with the upper robot unit in the front and the lower robot unit in the back, and then the fourth step is performed again;

[0129] If there is an obstacle ahead and the cross-sectional area S of the obstacle is greater than S0, or the change in the pipe diameter ahead is too large for the pipeline inspection robot to pass through in a separated form, the gear train structure 18 will wind and retract each cable 15 onto the corresponding pulley 19 synchronously, so that the upper robot unit and the lower robot unit are fitted into an integral form;

[0130] Subsequently, the leg and foot structures of the pipeline inspection robot are divided into two groups as symmetrically as possible. The two groups of leg and foot structures alternately lift and fall. When each group of leg and foot structures is lifted for the first time, in each leg and foot structure, the adduction and abduction drive 13 drives the Mecanum wheel to lift off the inner wall of the pipeline through the calf structure, so that the inner end of the pawl 16 rotates to the side close to the inner wall of the pipeline, and then the leg and foot structure falls, and the inner end of the pawl 16 is used as the structure contacting the inner wall of the pipeline, and it switches to walking forward;

[0131] The pipeline inspection robot moves forward in steps through obstacles or pipe sections with a sharp change in diameter, and performs the fourth step again.

[0132] Example 1

[0133] The following describes the working mode of the pipeline inspection robot by taking the pipeline inspection robot with three legs and three feet in each of the upper and lower robot units as an example:

[0134] Separate form:

[0135] When the upper robot unit and the lower robot unit of the pipeline inspection robot are separated, the pipeline inspection robot is in a separated state.

[0136] In the separated form, the upper robot unit and the lower robot unit respectively adjust the posture of their own leg and foot structures, and use the adduction and abduction drive motor 13 to drive the adsorption wheel 12 through the calf structure to abduct and contact and press the reaction force generated by the inner wall of the pipe to achieve the support of the upper robot unit and the lower robot unit in the pipe, and use the rolling of the adsorption wheel 12 to achieve independent movement of the upper and lower robot units.

[0137] In the separated configuration, the upper and lower robot units are connected only by a cable 15, allowing the upper and lower robots to move in a relative rotational and displaced manner. In particular, when the suction wheels 12 are Mecanum wheels, their excellent kinematic properties of controllable front-to-back angular displacement allow the upper and lower robots to easily rotate about their respective geometric center axes.

[0138] Overall form:

[0139] When the upper robot unit and the lower robot unit of the pipeline inspection robot are combined into an integral structure, the pipeline inspection robot is in an integral form, that is, a multi-legged obstacle avoidance form.

[0140] In the integrated form, the gear train structure 18 drives each cable 15 to be wound around the corresponding pulleys 19, shortening the length of the cable 15 between the upper robot unit and the lower robot unit until the upper robot unit and the lower robot unit's frame 1 are engaged; at this time, the leg and foot structures of the upper and lower robot units are evenly distributed along the circumference of the two frames 1 in an interlaced manner.

[0141] In the integrated form, the adduction and abduction drive motor 13 drives the suction wheel 12 to lift up and away from the inner wall of the pipe through the calf structure, with the square U-shaped structure at the inner end of the claw 16 serving as the structure in contact with the inner wall of the pipe; the six leg-foot structures are divided into two groups, with the three leg-foot structures located at the front and rear on the same side and the three leg-foot structures located in the middle on the opposite side forming a group, and the tripod structure stably supports the pipeline inspection robot.

[0142] When the pipeline inspection robot walks, one step includes the following processes:

[0143] In the first step, among the three leg and foot structures of the first group, the adduction and abduction drive 13 drives the foot claw 16 to lift upward through the thigh 17 and the calf structure 9, and the forward and backward swing drive 14 drives the foot claw 16 to swing forward in the lifted state through the thigh 17 and the calf structure 9;

[0144] In the second step, among the three leg and foot structures of the first group, the adduction and abduction drive 13 drives the foot claw 16 downward through the thigh 17 and the calf structure 9 to support the pipeline inspection robot;

[0145] At the same time, the three leg and foot structures of the second group are lifted up according to the method of the first step;

[0146] In the third step, among the three leg and foot structures of the first group, the front and rear swing drive 14 drives the foot claw 16 to swing backward in a downward swing state through the thigh 17 and the calf structure 9, so that the pipeline inspection robot moves forward;

[0147] At the same time, the three leg and foot structures of the second group swing forward in a high-lifted state according to the method of the first step;

[0148] In the fourth step, among the three leg and foot structures of the second group, the adduction and abduction driving motor 13 drives the foot claw 16 to swing downward and land on the ground through the thigh 17 and the calf structure 9 to support the pipeline inspection robot.

[0149] The pipeline inspection robot repeats the process of steps 1 to 4 to move forward.

[0150] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0151] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A dual-state special pipeline inspection robot based on a line-driven metamorphosis, provided with a robot unit capable of climbing a wall and walking in an adsorption manner, the robot unit comprising a frame (1) and a leg-foot structure mounted on the frame (1), the front end structure of the leg-foot structure outputting a forward and backward swinging and inward and outward movement to the terminal structure, and utilizing the adsorption force between the adsorption wheel (12) of the terminal structure and the pipeline to achieve support and walking of the robot, characterized in that: There are two robot units, one of which is located at the top and serves as an upper robot unit, and the other is located at the bottom and serves as a lower robot unit; Also includes a gear train structure (18), a pulley (19) and a cable (15); A gear train structure (18) is installed at the bottom center of the frame (1) in the upper robot unit; The pulleys (19) and the cables (15) are arranged in a one-to-one correspondence with the leg and foot structures in the upper robot unit, and each pulley (19) is evenly distributed on the inner side of each leg and foot structure in the circumferential direction of the gear train structure (18), and is rotatably mounted and connected to the frame (1) of the upper robot unit; The cable (15) is tensioned and wound around the corresponding pulley (19), and its bottom end and top end are respectively connected and fixed to the frame (1) of the lower robot unit and the upper robot unit, and the connection point is located on the inner side of the corresponding leg and foot structure; The gear train structure (18) outputs a motion driving each of the pulleys (19) to rotate synchronously, so that the cable (15) is wound around the corresponding pulley (19) in turns to shorten the length of the cable (15) between the lower robot unit and the upper robot unit, or the cable (15) is detached from the corresponding pulley (19) in turns to lengthen the length of the cable (15) between the lower robot unit and the upper robot unit; When the top and bottom ends of the cable (15) are facing each other vertically, the leg and foot structures of the upper robot unit and the lower robot unit are arranged in a staggered manner along the circumferential direction in a top view projection plane.

2. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 1 is characterized in that: The leg and foot structure comprises a front and rear swing drive (14), a thigh (17), an adduction and abduction drive (13), a calf structure (9), and the suction wheel (12); The thigh (17) is located on the outside of the corresponding frame (1), and its inner end is rotatably connected to the frame (1), forming a forward and backward swing rotation pair between the thigh and the frame to support the thigh to swing forward or backward with its inner end as the swing axis; The front-to-back swing driving machine (14) serves as the front end structure of the leg-foot structure, with its fixed end fixedly mounted on the frame (1), and its output end rotatably connected to the inner end of the thigh, driving the thigh to swing forward or backward under the support of the front-to-back swing rotation pair; The fixed end of the adduction and abduction driving machine (13) is fixed to the outer end of the thigh (17), and the output end thereof is connected to the inner end of the calf structure (9), driving the adsorption wheel (12) connected to the outer end of the calf structure (9) to adduct or abduct relative to the thigh (17).

3. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 2 is characterized in that: The calf structure (9) comprises an active rod (10), a driven rod (11) and a foot claw (16), and forms an unequal length double crank four-link structure with the thigh (17); The inner end of the active rod (10) serves as the inner end of the calf structure (9), is connected to the output end of the adduction and abduction driving machine (13), and its outer end is hinged to the middle part of the foot claw (16); the inner end and outer end of the driven rod (11) are hinged to the outer end of the thigh (17) and the inner end of the foot claw (16) respectively; the adsorption wheel (12) is rotatably mounted to the outer end of the foot claw (16) and is axially connected to the single-foot driving machine.

4. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 3 is characterized by: The adsorption wheel (12) is a Mecanum wheel.

5. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 1 is characterized in that: The gear train structure (18) includes a center wheel, a bevel gear and a transmission shaft; The center wheel is located at the bottom center of the frame (1) and is equipped with a center wheel driving machine for driving its own fixed axis rotation; the bevel gear and the transmission shaft are arranged in a one-to-one correspondence with the pulley (19); the pulley (19) is fixed to the transmission shaft and is rotatably connected to the frame (1) through the transmission shaft, and the bevel gear meshing with the center wheel is fixedly installed on one end of the transmission shaft facing the center wheel.

6. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 1 is characterized in that: The bottom of the frame (1) in the upper robot unit and the top of the frame (1) in the lower robot unit are in a mortise and tenon structure that fits together.

7. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 1 is characterized in that: The frame (1) is in the form of a regular triangular prism-like structure, and the robot unit is provided with three leg and foot structures evenly distributed around the circumference.

8. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 1 is characterized in that: An interface (20) is provided on the top of the frame (1) of the upper robot unit.

9. The dual-state special pipeline inspection robot based on line-driven metamorphosis according to claim 3 is characterized by: The inner end of the foot claw (16) is a square U-shaped structure with the opening facing inward, and an anti-slip pad is fixed to the end of the square U-shaped structure; The foot claw (16) is a hollow structure, and a storage cavity for storing tools is formed inside the foot claw (16).

10. A control method for a dual-state special pipeline inspection robot based on a wire-driven metamorphosis, wherein the dual-state special pipeline inspection robot based on a wire-driven metamorphosis as claimed in claim 4 is used to perform internal operations on a pipeline, characterized in that: The following steps are involved: The first step is to select a leg and foot structure of appropriate size according to the operation pipeline environment and install it on the frame (1) of the upper and lower single-body robots. Then, according to the operation type, select appropriate terrain exploration equipment and operation equipment, and install the terrain exploration equipment and operation equipment on the top of the frame (1) of the upper single-body robot through the interface (20); In the second step, the pipeline inspection robot enters the pipeline in a separated state in which the upper robot unit and the lower machine unit are separated and connected only by a rope (15). In the initial state, the geometric center axes of the upper robot unit and the lower machine unit coincide with each other, and the leg and foot structures of the upper robot unit and the lower robot unit coincide with each other in a one-to-one correspondence in the top projection plane. The upper robot and the lower robot adjust their postures respectively: Each adduction and abduction drive (13) drives the Mecanum wheel to abduct relative to the thigh (17) via the thigh (17) and the calf structure (9), and adjusts the contact between the Mecanum wheel and the inner wall of the pipe so that the upper robot unit and the lower robot unit are firmly supported inside the pipe; In the third step, in the upper single-body robot, each single-foot drive mechanism drives each Mecanum wheel to act in coordination, enabling the upper single-body robot to move forward a certain distance first, forming a state where the upper single-body robot is in the front and the lower single-body robot is in the rear. Subsequently, the single-foot drive mechanisms of the upper single-body robot and the lower single-body robot drive each Mecanum wheel to act in coordination, enabling the pipeline inspection robot to maintain the state where the upper single-body robot is in the front and the lower single-body robot is in the rear and move forward in a wheeled manner inside the pipeline; In the fourth step, the terrain exploration device surveys the terrain ahead inside the pipeline: If the terrain ahead is impassable or the pipeline inspection robot has reached the operation end position, the pipeline inspection robot retreats outside the pipeline and ends the operation; If the terrain ahead is a bend, proceed to the fifth step; If the terrain ahead is a straight pipe, proceed to the sixth step; In the fifth step, each Mecanum wheel acts in coordination to drive at least one of the upper robot single-body and the lower single-body robot to rotate around its own geometric center axis, making the relative rotation angle between the two 180°. At this time, the upper robot single-body and the lower single-body robot form a three-degree-of-freedom spherical joint structure, enabling the upper robot single-body and the lower single-body robot to rotate at their connection and move forward in a wheeled manner; During the process of passing through the bend, the terrain exploration device keeps surveying the terrain ahead inside the pipeline: If there is an obstacle with a cross-sectional area S > S0 ahead, the pipeline inspection robot retreats outside the pipeline and ends the operation; If there is an obstacle ahead and the cross-sectional area S of the obstacle < S0, in the upper single-body robot, each Mecanum wheel acts in coordination to make the upper single-body robot rotate around its own geometric center axis until each Mecanum wheel bypasses the obstacle. During this process, in the lower single-body robot, each Mecanum wheel acts in coordination to make the lower single-body robot rotate adaptively around its own geometric center axis to maintain the three-degree-of-freedom spherical joint structure formed by the upper robot single-body and the lower single-body robot; Subsequently, the lower single-body robot follows the movement of the upper single-body robot. Each Mecanum wheel in the lower single-body robot acts in coordination to make the lower single-body robot rotate around its own geometric center axis until each Mecanum wheel bypasses the obstacle. During this process, in the upper single-body robot, each Mecanum wheel acts in coordination to make the upper single-body robot rotate adaptively around its own geometric center axis to maintain the three-degree-of-freedom spherical joint structure formed by the upper robot single-body and the lower single-body robot; After that, the pipeline inspection robot moves forward in a wheeled manner inside the pipeline with the upper single-body robot in the front and the lower single-body robot in the rear, and performs the fourth step again; where S0 is the preset allowable cross-sectional area of the obstacle; If there is no obstacle ahead, the pipeline robot maintains its posture and moves forward in a wheeled manner until it passes through the bend. Subsequently, at least one of the upper robot single-body and the lower single-body robot rotates around its own geometric center axis to reset, and the fourth step is performed again; In the sixth step, further judge the terrain ahead: If there is no obstacle ahead, the pipeline inspection robot maintains the state where the upper single-body robot is in the front and the lower single-body robot is in the rear and moves forward in a wheeled manner inside the pipeline, and performs the fourth step again; If there is an obstacle ahead and the cross-sectional area S of the obstacle is less than S0, in the upper single-body robot, each Mecanum wheel acts in coordination to make the upper single-body robot rotate around its own geometric central axis until each Mecanum wheel bypasses the obstacle; Subsequently, the lower single-body robot follows the movement of the upper single-body robot. Each Mecanum wheel in the lower single-body robot acts in coordination to make the lower single-body robot rotate around its own geometric central axis until each Mecanum wheel bypasses the obstacle; After that, the pipeline inspection robot moves forward in a wheeled manner in the pipeline with the upper single-body robot in front and the lower single-body robot behind, and repeats the fourth step; If there is an obstacle ahead and the cross-sectional area S of the obstacle is greater than S0, or the change in the pipe diameter ahead is too large for the pipeline inspection robot to pass in the separated form, the gear train structure (18) will synchronously wind and retract each cable (15) onto the corresponding pulley (19), so that the upper robot single-body and the lower robot single-body are fitted into an integral form; Subsequently, the leg-foot structures of the pipeline inspection robot are divided into two groups as symmetrically as possible. The two groups of leg-foot structures alternately lift and fall. When each group of leg-foot structures is lifted for the first time, in each leg-foot structure, the adduction-abduction drive (13) drives the Mecanum wheel to lift and脱离 the inner wall of the pipeline through the calf structure, so that the inner end of the paw (16) rotates to the side close to the inner wall of the pipeline. Subsequently, the leg-foot structure falls, and the inner end of the paw (16) is used as the structure in contact with the inner wall of the pipeline, and switches to walking forward; The pipeline inspection robot walks forward through the obstacle or the pipe section with a sharp change in pipe diameter, and repeats the fourth step.

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