Multi-pipe-diameter staggered pipe-holding wall-climbing robot for ultrasonic detection of outer pipeline

Abstract

The invention discloses a multi-pipe-diameter staggered pipe-holding wall-climbing robot for ultrasonic detection of an outer pipeline. The multi-pipe-diameter staggered pipe-holding wall-climbing robot comprises a staggered pipe-holding main body, a front driving wheel unit, a driven wheel unit, a rear driving wheel unit, a pipe-holding driving unit and an ultrasonic detection unit. According to the robot, the rope is tightened through the winding motor, self-adaptive staggered clasping adsorption of the pipeline is achieved, then stable wall climbing and ultrasonic detection are conducted, and a plurality of robots can be spliced end to end in a staggered mode so that the current pipeline can be moved to an adjacent pipe and clasped. The robot is small, exquisite, light, reasonable in structure, easy to control, stable in transmission, efficient, energy-saving and high in detection performance, has obstacle crossing ability and a multi-probe system capable of being arranged in a diversified mode, and can design parameters of a staggered pipe holding body according to the outer diameter range of a pipeline needing to be detected; the device can adapt to automatic detection of pipelines with different diameters, especially pipelines with small diameters, by selecting the number of the sub-segments of the staggered pipe holding main body, and can guarantee the safety of workers while guaranteeing the safe operation of the pipelines.

Description

Technical Field

[0001] The present invention relates to the field of pipeline robots, and more specifically to a multi-diameter dislocated pipe-holding wall-climbing robot for ultrasonic detection of external pipelines. Background Art

[0002] Pipeline transportation is one of the five major means of material transportation and is widely used in important fields such as national economy, national defense construction, municipal livelihood, etc. However, pipelines work in harsh environments and are easily damaged. Local damage can also lead to global paralysis. The leakage of resources such as oil and gas caused by pipeline rupture can cause huge economic losses and ecological pollution. Therefore, pipeline safety issues are particularly prominent. At the same time, it is difficult to effectively monitor the safety status of pipelines by manual means alone, and manual pipeline inspection methods are inefficient, expensive, and have great safety hazards.

[0003] In addition, the existing wall-climbing robots used for external pipeline inspection are large in size, large in mass, high in energy consumption, complex in design, difficult to control, poor in stability, poor in reliability, poor in obstacle crossing ability, and low in detection efficiency, making it difficult to adapt to the detection of pipelines with different diameters. Some wall-climbing robots for external pipeline inspection use magnetic adsorption, but this technology has many problems. For example, pipelines are usually rusted, corroded, and covered by attachments, which will weaken the magnetic adsorption of pipelines, thereby increasing the difficulty of achieving stable adsorption through magnetic force, and magnetic adsorption is not suitable for pipelines with weak magnetism or non-magnetic materials due to coatings such as anti-corrosion films. Some wall-climbing robots for external pipeline inspection perform pipe climbing inspection through a pipe holding mechanism or a circular track laid outside the pipeline, but it is difficult to inspect pipelines of different diameters, and the cost is high and the efficiency is low. At the same time, some wall-climbing robots for external pipeline inspection are not suitable for pipelines with smaller diameters because they are too large in size or the detection equipment they carry is too large or the adsorption force is insufficient or the maneuverability is limited. Some external pipeline inspection wall-climbing robots use visual inspection, which is difficult to detect tiny defects and can only provide information on the pipeline surface but cannot detect internal defects. It has high cost, low efficiency, low accuracy, limited data, and is easily affected by the environment (for example, the pipeline is sometimes covered by attachments that hide the corroded or damaged parts of the pipeline, causing visual inspection to fail), and cannot adapt to dim environments.

[0004] Therefore, developing a robot with a reasonable structure, compact and light weight, convenient design, simple control, stable movement, low energy consumption, high-performance ultrasonic detection function and good obstacle crossing ability, and the ability to adaptively hold and adsorb pipes of different diameters, especially those with smaller diameters, can solve the above problems, realize the automation of external pipeline detection, and ensure the safety of employees while improving efficiency. Summary of the invention

[0005] The present invention provides a multi-diameter dislocated pipe-holding and wall-climbing robot for external pipeline ultrasonic detection in order to realize miniaturization, lightness, simplification, economy, efficiency, stabilization, reliability, multi-diameter applicability, high-performance ultrasonic detection and obstacle crossing functions of the external pipeline detection robot.

[0006] The objective of the present invention is achieved through the following technical solutions: a multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic detection, comprising a dislocated pipe-holding body, a front driving wheel unit, a driven wheel unit, a rear driving wheel unit, a pipe-holding driving unit and an ultrasonic detection unit;

[0007] The staggered pipe holding body is composed of a plurality of sub-segments connected in a staggered manner in sequence, and each sub-segment includes a first rigid sub-body, a second rigid sub-body, a first rigid connecting rod, and a second rigid connecting rod; the first rigid sub-body and the second rigid sub-body are arranged in a staggered mirror image and are hinged to form an inverted V-shaped structure of the sub-segment; the first rigid connecting rod and the second rigid connecting rod stagger the inverted V-shaped structures of the front and rear sub-segments, and the two inverted V-shaped structures are staggered and hinged to form an inverted W-shaped structure through adjacent sub-bodies;

[0008] The front driving wheel unit has a first wheel hub motor, which is staggered and hinged with the first rigid sub-body at the front end of the staggered tube holding body; the rear driving wheel unit has a second wheel hub motor, which is staggered and hinged with the second rigid sub-body at the rear end of the staggered tube holding body; the driven wheel unit is hinged at the bottom of the second rigid sub-body;

[0009] The pipe holding drive unit comprises a winding motor, a winding drum and a wire rope; the winding motor is fixed on the rear driving wheel unit, the winding drum is fixed on the rotating shaft of the winding motor, one end of the wire rope is fixed on the winding drum, and the other end passes through the rear driving wheel unit, each sub-segment of the dislocated pipe holding body and the bottom of the front driving wheel unit in sequence, and then passes back to the winding drum in sequence and is fixed;

[0010] The ultrasonic detection unit is fixed on the front driving wheel unit, and ultrasonic detection of the external pipeline is realized by an ultrasonic probe;

[0011] By driving the winding motor to rotate the winding drum to tighten the rope, the robot is bent toward one side of the rope and tightly adheres to the outer surface of the pipe; by controlling the two hub motors, the robot is allowed to climb the pipe in a circumferential direction.

[0012] Furthermore, the first rigid sub-body has a frame structure, with concave structures at the top and bottom, equal wall thicknesses on the left and right sides, and transverse through-holes at the upper and lower ends on both the left and right sides. A vertical support column is provided in the middle, dividing the first rigid sub-body into left and right hollow areas. Transverse through-holes are provided in the middle of both the left and right sides and the middle of the support column of the first rigid sub-body; the second rigid sub-body is hinged to the first rigid sub-body through the upper transverse through-holes on both the left and right sides. The inner wall on the right side of the first rigid sub-body contacts the outer wall on the right side of the second rigid sub-body, and the outer wall on the left side of the first rigid sub-body contacts the inner wall on the left side of the second rigid sub-body, with a distance of one wall thickness错开 horizontally between the two.

[0013] Furthermore, through-holes are provided at both ends of the first rigid link, and it is hinged to the middle transverse through-holes of the first rigid sub-bodies of the front and rear sub-segments, located in the left hollow area of the first rigid sub-body and the second rigid sub-body; through-holes are provided at both ends of the second rigid link, and it is hinged to the middle transverse through-holes of the second rigid sub-bodies of the front and rear sub-segments, located in the right hollow area of the first rigid sub-body and the second rigid sub-body.

[0014] Furthermore, the front drive wheel unit includes a front wheel connecting member, which has a U-shaped structure lying flat forward. Transverse through-holes are provided at the front ends on both the left and right sides for fixing a first threaded fixed shaft of a first hub motor. A transverse through-hole is provided at the lower end of the part connecting the rear ends on both the left and right sides in the U-shaped structure, and it is hinged to the lower transverse through-holes on both the left and right sides of the first rigid sub-body at the very front end of the misaligned pipe-holding main body; a vertical support column is formed by hollowing out from both the left and right sides to the middle of the part connecting both the left and right sides in the U-shaped structure. A transverse through-hole is provided in the middle of the support column. By adding a second rigid link, through-holes at both ends thereof are respectively hinged to the transverse through-hole of the support column of the front wheel connecting member and the middle transverse through-hole of the second rigid sub-body at the very front end of the misaligned pipe-holding main body.

[0015] Furthermore, the rear drive wheel unit includes a rear wheel connection chamber, which is composed of an L-shaped structure and a U-shaped structure lying flat backward; transverse through-holes are provided at the rear ends on both the left and right sides of the U-shaped structure for fixing a second threaded fixed shaft of a second hub motor. A transverse through-hole is provided at the lower end of the part connecting the front ends on both the left and right sides in the U-shaped structure, and it is hinged to the lower transverse through-holes on both the left and right sides of the second rigid sub-body at the very rear end of the misaligned pipe-holding main body; the L-shaped structure is a hollow chamber body for placing a circuit board arranged above and behind the U-shaped structure; a vertical support column is formed by hollowing out from both the left and right sides to the middle of the part connecting both the left and right sides in the U-shaped structure. A transverse through-hole is provided in the middle of the support column. Through-holes at both ends of the first rigid link at the very rear end of the misaligned pipe-holding main body are respectively hinged to the transverse through-hole of the support column of the rear wheel connection chamber and the middle transverse through-hole of the first rigid sub-body at the very rear end of the misaligned pipe-holding main body, and the second rigid link is removed from the sub-segment at the very rear end of the misaligned pipe-holding main body.

[0016] Furthermore, the front and rear sub-segments of the staggered pipe-holding body are staggered and connected without structural interference, and must satisfy t2≤2t1, t3≥2t2, and 2t1<t3≤(T-2t1) / 2, wherein t1 is the wall thickness on the left and right sides of the rigid sub-body, t2 is the thickness of the rigid connecting rod, t3 is the width of each hollow area of ​​the rigid sub-body, and T is the width of the rigid sub-body; there is no structural interference between the driven wheel units of the front and rear sub-segments of the staggered pipe-holding body when the robot staggers the pipe, and must satisfy t4<2t1, wherein t4 is the thickness of the driven wheel.

[0017] Furthermore, the minimum number of sub-segments of the dislocation pipe holding body is determined according to the pipe diameter, the dislocation pipe holding body holds the outer pipe for at least one circle, and when the dislocation pipe holding body holds the outer pipe for one circle, the pipe diameter D and the minimum number of sub-segments N of the dislocation pipe holding body are equal. min satisfy , where H is the distance from the center of the horizontal through hole in the middle of the rigid sub-body to the ground when the robot is placed flat on the ground, and C is the center distance of the through holes at both ends of the rigid connecting rod. It is an intermediate parameter. When the pipe diameter D is determined, it is first calculated , then Round up to get the minimum number of sub-segments N min ; When the staggered pipe holding body is required to hold the outer pipe n times, Multiply by n and round up to get the number N of sub-segments of the misaligned pipe body.

[0018] Furthermore, the parameter design of the staggered pipe holding body is specifically as follows:

[0019] The robot has a minimum applicable pipe diameter D min , the robot is suitable for pipe diameter D ≥ D min ;

[0020] When the robot holds the pipe in a misaligned position, the pipe diameter D, the distance h from the center of the transverse through hole at the lower end of the rigid sub-body to the ground when the robot is placed flat on the ground, the center distance L between the transverse through hole at the upper end and the transverse through hole at the lower end of the rigid sub-body, and the angle between the straight line connecting the transverse through hole at the upper end and the transverse through hole at the lower end of the first rigid sub-body and the straight line connecting the transverse through hole at the upper end and the transverse through hole at the lower end of the second rigid sub-body in the same sub-segment , the angle between the straight line connecting the upper and lower transverse through holes of the second rigid sub-body and the straight line connecting the upper and lower transverse through holes of the first rigid sub-body of the next sub-segment Satisfying formula (1):

[0021] (1)

[0022] L. , The center distance C of the through holes at both ends of the rigid connecting rod satisfies formula (2):

[0023] (2)

[0024] The degree of bending when the robot holds the pipe in a misaligned position depends on the outer diameter of the pipe. Minimum value of and The maximum value of Determined by the structure of the robot, when the robot reaches the limit of bending, , , D=D min ;

[0025] First design the rigid sub-body shape and determine when the robot reaches the limit bending degree. and And h, and then determine the range of pipe diameter D applicable to the robot according to the different outer diameters of the various pipes to be detected. , D=D min Substitute and h into formula (1) to obtain L; or, first design the rigid subbody shape and L, and then calculate D = D using formula (1) min , and verify D min Is it less than or equal to the minimum pipe diameter in the pipe to be tested? If not, modify L until it is satisfied. , Substitute C and L into formula (2) to obtain C; the calculation formula for H is , where the robot is flat on the ground , The value of is determined when the rigid subbody shape is designed;

[0026] According to D=D min , H and C to calculate the minimum number of sub-segments required for the robot to hold the minimum diameter pipe in a misaligned manner , , t1 and T satisfy ; Then, combined with t2≤2t1, t3≥2t2 and 2t1<t3≤(T-2t1) / 2, determine the wall thickness t1 on the left and right sides of the rigid sub-body, the thickness t2 of the rigid connecting rod, the width t3 of each hollow area of ​​the rigid sub-body and the width T of the rigid sub-body.

[0027] Furthermore, the winding motor adopts a servo motor, and the change of the servo motor torque is reflected by real-time monitoring of the change of the servo motor current:

[0028] When the servo motor current increases, it means that the robot encounters a raised obstacle, and the winding motor is controlled to release the wire rope to restore the torque. When the raised obstacle becomes smaller or the robot passes over the raised obstacle, the servo motor current decreases, and the winding motor is controlled to tighten the wire rope to maintain the torque.

[0029] When the servo motor current becomes smaller, it means that the robot encounters a recessed obstacle, and the winding motor is controlled to tighten the rope to restore the torque. When the recessed obstacle becomes smaller or the robot crosses the recessed obstacle, the servo motor current becomes larger, and the winding motor is controlled to release the rope to maintain the torque.

[0030] Furthermore, by splicing three or more robots with their heads and tails staggered, the spliced ​​robots can automatically move from the current pipe to the adjacent pipe and hold it tightly; by installing a spring between the two adjacent front and rear holes through which the rope passes, the rope can be automatically reset and maintained after being lengthened when the robot is bent; during the splicing process, the frontmost robot removes the rear drive wheel unit and fixes the winding motor on the last sub-segment, the robot in the middle removes the front drive wheel unit and the rear drive wheel unit and fixes the winding motor on the last sub-segment, the rearmost robot removes the front drive wheel unit, the rope of the rear robot passes through the bottom of the second rigid sub-body of the last sub-segment of the front robot, and no rigid connecting rod is installed between the two sub-segments at the splicing.

[0031] The beneficial effects of the present invention are:

[0032] 1. The robot of the present invention can rotate the winding drum to tighten the wire rope by driving the winding motor, so that the robot can bend in a dislocated manner, thereby realizing the robot's adaptive and stable holding and adsorption of the pipeline, and is not affected by the pipeline material and surface conditions. At the same time, the more the robot holds the pipeline, the more stable its adsorption movement on the outer pipeline surface.

[0033] 2. The robot of the present invention has several hollow areas, adopts lightweight materials, and is composed of several offset pipe-holding body sub-segments and driven wheel units. The parameters of the offset pipe-holding body can be designed according to the outer diameter range of the pipe to be detected, and the number of the offset pipe-holding body sub-segments can be selected according to the pipe diameter. Due to the offset design, structural interference can be avoided when the robot holds the pipe in an offset manner. After removing the wire rope, the sub-segments can be easily added or removed, and the assembled robot can also be disassembled into multiple parts according to different numbers of sub-segments for storage, transportation and subsequent assembly and use. The driven wheel units can also be easily added or removed to reasonably optimize their layout. Therefore, the robot is compact and light, convenient in design, and reasonable in structure. It can adapt to pipes of different diameters, especially pipes with smaller diameters.

[0034] 3. The driving device of the robot of the present invention has only two wheel hub motors and one winding motor, has the ability to overcome obstacles, is simple to control, has stable movement and low energy consumption; the robot of the present invention is assembled with a rigid sub-body, a rigid connecting rod, a rigid front wheel connecting piece, a rigid rear wheel connecting bin and pins, and uses a driven wheel unit to assist in climbing the pipe, thereby ensuring the stability of the robot's transmission, adsorption and movement.

[0035] 4. The robot of the present invention adopts ultrasonic detection, which can detect tiny defects inside the pipeline. It has low cost, high efficiency, high precision, rich data, and is not easily affected by the environment. At the same time, multiple ultrasonic probes can be used and arranged in a diversified manner. The multi-probe system of the robot can be composed of a variety of different ultrasonic probes, and a variety of ultrasonic detection technologies can also be integrated to improve the detection range and performance and meet a variety of detection requirements, thereby realizing the automation of external pipeline detection, improving economic benefits, ensuring the safe operation of the pipeline and protecting the safety of employees.

[0036] 5. In order to further improve the automation and working efficiency of the robot, the present invention also designs multiple robots to hold adjacent pipes, and splices multiple robots head to tail in a staggered manner to realize that the spliced ​​robots automatically move from the current pipe to the adjacent pipe and hold it tightly. A spring is installed between the two adjacent holes in front and behind where the wire rope passes, so as to realize the automatic reset and retention of the wire rope after it is lengthened when the robot is bent. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 This is a schematic diagram of a multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing;

[0039] Figure 2 This is a schematic diagram of the dislocated pipe holding body;

[0040] Figure 3 Schematic diagram of the main sub-segment of the dislocated pipe-holding structure, where (a) is a single sub-segment structure diagram, (b) is a rigid sub-body structure diagram, and (c) is a rigid connecting rod structure diagram;

[0041] Figure 4 Schematic diagrams of the front drive wheel unit from two different perspectives;

[0042] Figure 5 Schematic diagrams of the driven wheel unit from two different perspectives;

[0043] Figure 6 is a schematic diagram of a rear drive wheel unit;

[0044] Figure 7 This is a schematic diagram of the tube holding drive unit;

[0045] Figure 8 is a schematic diagram of an ultrasonic detection unit;

[0046] Fig. 9 This is a schematic diagram of the dislocation design of the dislocation pipe holding body;

[0047] Fig.10 It is a parameter diagram of a certain sub-segment when the front and rear sub-segments of the dislocated holding pipe body are tightly dislocated and connected;

[0048] Fig.11 It is a schematic diagram of parameters of the dislocation pipe holding body holding the outer pipe in one circle;

[0049] Fig.12 This is a schematic diagram of the parameters when the robot is lying flat on the ground without bending;

[0050] Fig.13 This is a schematic diagram of the robot after the three robots are spliced ​​end to end;

[0051] Fig.14 is a schematic diagram of a first robot with a driven wheel unit on one side approaching an adjacent pipeline;

[0052] Fig.15 A schematic diagram of the first robot holding onto an adjacent pipe;

[0053] Fig.16 is a schematic diagram of the third robot automatically returning to the straightened state and maintaining the state under the action of the spring;

[0054] Fig.17 This is a schematic diagram of the second robot and the third robot holding adjacent pipes in sequence;

[0055] In the figure: 1. first rigid subbody, 2. second rigid subbody, 3. first rigid connecting rod, 4. second rigid connecting rod, 5. front wheel connecting piece, 6. first threaded fixed shaft, 7. first hub motor, 8. connecting shaft, 9. driven wheel, 10. rear wheel connecting compartment, 11. compartment cover, 12. second threaded fixed shaft, 13. second hub motor, 14. winding motor, 15. winding drum, 16. rope, 17. fixed bracket, 18. rotating bracket, 19. ultrasonic probe. DETAILED DESCRIPTION

[0056] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0057] It should be clear that the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0058] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0059] like Figure 1 As shown, the present invention provides a multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic detection, comprising a dislocated pipe-holding body, a front driving wheel unit, a driven wheel unit, a rear driving wheel unit, a pipe-holding driving unit and an ultrasonic detection unit.

[0060] like Figure 2 As shown, the staggered pipe holding body is composed of N segments. Figure 3 As shown in (a), each sub-segment includes a first rigid sub-body 1, a second rigid sub-body 2, a first rigid link 3, and a second rigid link 4. Figure 3 As shown in (b), the first rigid sub-body 1 is a frame-type structure with a concave structure at the top and bottom. The upper and lower ends of the left and right sides of the first rigid sub-body 1 are provided with horizontal through holes from left to right. A vertical support column is provided in the middle of the first rigid sub-body 1, dividing the first rigid sub-body 1 into two left and right hollow areas, and horizontal through holes are provided in the middle of the left and right sides of the first rigid sub-body 1 and the middle of the support column; the wall thickness of the left and right sides of the first rigid sub-body 1 is equal. The second rigid sub-body 2 has the same structure as the first rigid sub-body 1, and is arranged in a staggered mirror image with the first rigid sub-body 1. The two are hinged through the upper transverse through holes on the left and right sides. The right inner wall of the first rigid sub-body 1 contacts the right outer wall of the second rigid sub-body 2, and the left outer wall of the first rigid sub-body 1 contacts the left inner wall of the second rigid sub-body 2. The two are staggered laterally by a distance of wall thickness, thereby forming an inverted V-shaped structure of the sub-segment. The second rigid sub-body 2 and the first rigid sub-body 1 of the next sub-segment are hinged through the lower transverse through holes on the left and right sides. The right inner wall of the second rigid sub-body 2 contacts the right outer wall of the first rigid sub-body 1 of the next sub-segment, and the left outer wall of the second rigid sub-body 2 contacts the left inner wall of the first rigid sub-body 1 of the next sub-segment. The two are staggered laterally by a distance of wall thickness. Figure 3As shown in (c), the first rigid link 3 is a rod structure with through holes at both ends, which is hinged to the middle transverse through hole of the first rigid sub-body 1 of the front and rear sub-segments, and is located in the left hollow area of ​​the first rigid sub-body 1 and the second rigid sub-body 2; the second rigid link 4 has the same structure as the first rigid link 3, and the through holes at both ends of the second rigid link 4 are hinged to the middle transverse through hole of the second rigid sub-body 2 of the front and rear sub-segments, and is located in the right hollow area of ​​the first rigid sub-body 1 and the second rigid sub-body 2; thus, the first rigid link 3 and the second rigid link 4 connect the inverted V-shaped structure of the front and rear sub-segments in a staggered manner.

[0061] like Figure 4 As shown, the front drive wheel unit includes a front wheel connecting member 5, a first threaded fixed shaft 6 and a first wheel hub motor 7; the front wheel connecting member 5 is a U-shaped structure lying forward, with two threaded holes on the right side, and transverse through holes on the front ends of the left and right sides, and the lower end of the part connecting the rear ends of the left and right sides in the U-shaped structure is provided with a transverse through hole, which is hinged with the lower end transverse through holes on the left and right sides of the first rigid sub-body 1 at the front end of the offset tube holding body; the middle part of the first threaded fixed shaft 6 is smooth, and both sides have external threads, and the first threaded fixed shaft 6 is fixed to the transverse through holes on the front ends of the left and right sides of the front wheel connecting member 5 by assembling nuts on the external threads; the first wheel hub motor 7 is located between the left and right sides of the front wheel connecting member 5, and the first wheel hub motor 7 is fixed to the middle of the first threaded fixed shaft 6 by assembling nuts on the external threads of the first threaded fixed shaft 6.

[0062] like Figure 5 As shown, the driven wheel unit includes a connecting shaft 8 and a driven wheel 9; the connecting shaft 8 is hinged to the bottom of the second rigid sub-body 2 of the offset pipe holding body; the driven wheel 9 is fixed on the connecting shaft 8 by a flat key, and is located at the concave structure of the second rigid sub-body 2 of the offset pipe holding body.

[0063] like Figure 6As shown in the figure, the rear drive wheel unit includes a rear wheel connection bin 10, a bin cover 11, a second threaded fixing shaft 12, and a second hub motor 13. The rear wheel connection bin 10 is composed of an L-shaped structure and a U-shaped structure lying flat backward. In this embodiment, seven through holes are opened on the left side of the U-shaped structure, transverse through holes are opened at the rear ends of both left and right sides, and a transverse through hole is opened at the lower end of the part connecting the front ends of both left and right sides in the U-shaped structure, and is hinged to the lower transverse through holes on both left and right sides of the second rigid body 2 at the rearmost end of the misaligned pipe-holding main body. The L-shaped structure is a hollow bin body for placing a circuit board arranged above and behind the U-shaped structure. The bin cover 11 is in a cuboid structure and is fixed to the rear of the hollow bin body of the rear wheel connection bin 10 by screws. The middle part of the second threaded fixing shaft 12 is smooth, and there are external threads on both sides. The second threaded fixing shaft 12 is fixed to the transverse through holes at the rear ends of both left and right sides of the U-shaped structure of the rear wheel connection bin 10 by assembling nuts on the external threads. The second hub motor 13 is located between the left and right sides of the U-shaped structure of the rear wheel connection bin 10, and the second hub motor 13 is fixed to the middle part of the second threaded fixing shaft 12 by assembling nuts on the external threads of the second threaded fixing shaft 12.

[0064] As Figure 7 shown in the figure, the pipe-holding drive unit includes a wire-winding motor 14, a wire-winding disc 15, and a wire rope 16. In this embodiment, the wire-winding motor 14 is a micro high-torque and high-precision motor, which is fixed outside the through hole on the left side of the U-shaped structure of the rear wheel connection bin 10 by six screws, and its rotating shaft extends into the inner side through the through hole. The middle part of the wire-winding disc 15 is in a shaft shape, and both sides are in a disc structure, which is fixed on the rotating shaft of the wire-winding motor 14 and is located between the left and right sides of the U-shaped structure of the rear wheel connection bin 10. One end of the wire rope 16 is fixed to the shaft of the wire-winding disc 15, and the other end sequentially passes through the rear wheel connection bin 10, the misaligned pipe-holding main body, and the bottom of the front wheel connector 5, and then sequentially passes through the front wheel connector 5, the misaligned pipe-holding main body, and the bottom of the rear wheel connection bin 10, and returns to the shaft of the wire-winding disc 15 and is fixed. Preferably, metal hollow rivets can be installed in the holes through which the wire rope 16 passes to reduce the wear of the wire rope during movement and improve the service life of the wire rope.

[0065] As Figure 8As shown, the ultrasonic detection unit includes a fixed bracket 17, a rotating bracket 18 and an ultrasonic probe 19; the fixed bracket 17 is a rectangular parallelepiped structure with two transverse through holes, a protruding cylindrical structure on the surface, and a threaded hole is opened on the outer side of the cylindrical structure, and the two transverse through holes of the fixed bracket 17 can be connected to the two threaded holes on the right side of the front wheel connecting member 5 by screws, so that the fixed bracket 17 is fixed to the right side of the front wheel connecting member 5; the rotating bracket 18 has a tubular structure, an axial structure outside the tubular structure, the symmetry axes of the two are perpendicular to each other, and a threaded hole is opened on the outer side of the tubular structure, the axial structure of the rotating bracket 18 is installed in the cylindrical structure of the fixed bracket 17, and the rotating bracket 18 can be fixed or rotated by screwing in the threaded hole of the cylindrical structure of the fixed bracket 17; the ultrasonic probe 19 is installed in the tubular structure of the rotating bracket 18, and the ultrasonic probe 19 can be fixed or moved by screwing in the threaded hole of the tubular structure of the rotating bracket 18.

[0066] Furthermore, if Figure 1 , Figure 4 and Figure 6 As shown, the left and right sides of the part connecting the left and right sides in the U-shaped structure of the front wheel connecting member 5 and the rear wheel connecting warehouse 10 are hollowed out to the middle to form a vertical support column, and a transverse through hole is opened in the middle of the support column. By adding a second rigid connecting rod 4, the through holes at both ends are hinged with the transverse through hole of the support column of the front wheel connecting member 5 and the middle transverse through hole of the second rigid sub-body 2 at the front end of the offset pipe holding body, and the through holes at both ends of the first rigid connecting rod 3 of the last terminal segment of the offset pipe holding body are hinged with the transverse through hole of the support column of the rear wheel connecting warehouse 10 and the middle transverse through hole of the first rigid sub-body 1 at the last end of the offset pipe holding body, so as to prevent the first hub motor 7 and the second hub motor 13 from detaching from the wall when the robot climbs the pipe, and the second rigid connecting rod 4 is removed from the last terminal segment of the offset pipe holding body to prevent it from interfering with the second hub motor 13.

[0067] Furthermore, if Figure 6 As shown, four through holes are opened on the top of the hollow chamber body of the rear wheel connection chamber 10 so that the wires of the first hub motor 7, the second hub motor 13, the winding motor 14 and the ultrasonic probe 19 can pass through and be connected to the circuit board in the rear wheel connection chamber 10.

[0068] Furthermore, the first hub motor 7 and the second hub motor 13 are wrapped with a rubber layer on the outside, and the driven wheel 9 is wrapped with a rubber tire with an asymmetric pattern on the outside to avoid wear and increase friction with the pipe surface to prevent the robot from slipping; the rope 16 is made of soft, anti-winding, wear-resistant and tensile-resistant nylon wire to better realize the robot's pipe-holding and adsorption movement.

[0069] Furthermore, the first rigid sub-body 1, the second rigid sub-body 2, the first rigid link 3, the second rigid link 4, the front wheel connecting member 5 and the rear wheel connecting bin 10 are all made of rigid and lightweight materials to ensure the movement stability of the robot and reduce the weight of the robot, and these parts are assembled and connected using round head pins to form a dislocation, that is, the front wheel connecting member 5, the sub-segments of the dislocated tube-holding body and the rear wheel connecting bin 10 are not on the same straight line, so that the robot can form a dislocated tube-holding shape.

[0070] The following is a detailed description of the design process of the multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing provided by the present invention.

[0071] 1. The staggered design of the robot.

[0072] In the present invention, the front and rear sub-segments of the staggered holding pipe body are staggered and connected, and there is no structural interference to hinder the cooperation. It is necessary to satisfy t2≤2t1, t3≥2t2, and 2t1<t3≤(T-2t1) / 2, where t1 is the wall thickness of the left and right sides of the rigid sub-body, t2 is the thickness of the rigid connecting rod, t3 is the width of each hollow area of ​​the rigid sub-body, and T is the width of the rigid sub-body. Fig. 9 shown.

[0073] Preferably, Fig.10 As shown, t2=2t1, t3=2t2=4t1, and T>2t1+2t3. At this time, the first rigid link 3 of the front and rear sub-segments of the offset pipe-holding body just fills the left hollow area of ​​the rigid sub-body, and the second rigid link 4 just fills the right hollow area of ​​the rigid sub-body. Therefore, the front and rear sub-segments can be tightly offset and connected to avoid lateral looseness and change the offset distance of the front and rear sub-segments.

[0074] In order to prevent interference between the driven wheel units of the front and rear sub-segments of the misaligned pipe-holding body when the robot is misaligned in holding the pipe, t4<2t1 must be satisfied, where t4 is the thickness of the driven wheel.

[0075] 2. Determine the minimum number of sub-segments of the offset pipe holding body based on the pipe diameter.

[0076] In order to enable the robot to hold the outer pipe surface tightly and stably, the dislocation pipe holding body should hold the outer pipe for at least one circle to prevent the robot from falling off during movement. The number of sub-segments N of the dislocation pipe holding body can be determined according to the pipe diameter D. The larger the pipe diameter or the more circles the robot holds the pipe (the more circles the robot holds, the more stable the robot's adsorption movement on the outer pipe surface), the more sub-segments the dislocation pipe holding body has.

[0077] When the dislocation pipe holding body holds the outer pipe for a circle, Fig.11 As shown, at this time N=14, the pipe diameter D and the minimum number of sub-segments N of the staggered pipe holding body min (N minis an integer) satisfies formula (1), since N min The result of calculation may be a decimal, so use Instead of N min :

[0078] (1)

[0079] Where H is the distance from the center of the horizontal through hole in the middle of the rigid subbody to the ground, such as Fig.12 As shown, at this time, the robot is not bent and lies flat on the ground, and C is the center distance of the through holes at both ends of the rigid connecting rod (the center distance of the middle transverse through holes of the first rigid sub-body of the front and rear sub-segments, that is, the center distance of the middle transverse through holes of the second rigid sub-body of the front and rear sub-segments).

[0080] When the pipe diameter D is determined, it can be calculated according to formula (1) , then Rounding up gives the minimum number of sub-segments N. min When the staggered pipe holding body is required to hold the outer pipe n times, Multiply by n and round up to the nearest integer to get the number N of sub-segments of the misaligned pipe body.

[0081] 3. Design the main body of the offset pipe holding device according to the outer diameter range of the pipe to be tested, and determine the parameters of the main body of the offset pipe holding device.

[0082] In order to enable the robot to hold the outer pipe surface tightly and stably, the offset pipe holding body holds the outer pipe for at least one circle to prevent it from falling off when the robot moves.

[0083] The robot has a minimum applicable pipe diameter D min , and the maximum applicable pipe diameter can be expanded by increasing the number of sub-segments of the dislocation pipe holding body, so the pipe diameter applicable to the robot is D ≥ D min , and can be based on D min The robot is designed based on the relationship between the robot and its structural parameters.

[0084] First, when the robot holds the pipe in a misaligned position, the pipe diameter D and the distance h from the center of the horizontal through hole at the lower end of the rigid sub-body to the ground (e.g. Fig.12 As shown, at this time, the robot is not bent and lies flat on the ground), the center distance L between the upper and lower transverse through holes of the rigid sub-body, and the angle between the straight line connecting the upper and lower transverse through holes of the first rigid sub-body and the straight line connecting the upper and lower transverse through holes of the second rigid sub-body of the same sub-segment , the angle between the straight line connecting the upper and lower transverse through holes of the second rigid sub-body and the straight line connecting the upper and lower transverse through holes of the first rigid sub-body of the next sub-segment Satisfy formula (2) (When the robot is misaligned and bent to hold the pipe, ):

[0085] (2)

[0086] Secondly, L. , The center distance C of the through holes at both ends of the rigid connecting rod satisfies formula (3):

[0087] (3)

[0088] The degree of bending when the robot holds the pipe in a misaligned position depends on the outer diameter of the pipe. The smaller the outer diameter of the pipe, the greater the degree of bending of the robot. The smaller, The bigger. Minimum value of and The maximum value of Determined by the robot structure, because when the robot continues to bend, it will stop bending due to structural interference, and the limit bending degree (maximum bending degree) will be reached at this time, and , , and also determined that the robot's minimum applicable pipe diameter is D = D min .

[0089] Therefore, when designing the robot's offset pipe-holding body, the rigid sub-body shape can be designed first to determine the robot's bending limit. and And h, and then determine the range of pipe diameter D that the robot needs to be applicable to according to the different outer diameters of the various pipes to be detected, that is, D ≥ D min , and D min A certain margin can be reserved, that is, it can be smaller than the minimum pipe diameter in the pipe to be tested, and then , D=D min Substitute h and h into formula (2) to obtain the size L of the rigid subbody (of course, you can also design the rigid subbody shape and L first, and then calculate D = D using formula (2) min , and verify D min Is it less than or equal to the minimum pipe diameter in the pipe to be tested? If not, modify L until it is satisfied. , Substitute L and L into formula (3) to obtain the center distance C of the through holes at both ends of the rigid connecting rod.

[0090] And H can be obtained by formula (4) (at this time the robot is not bent and is placed flat on the ground, ,and The value of can be determined when the rigid subbody shape is well designed):

[0091] (4)

[0092] So D = D min , H and C are substituted into formula (1) to calculate , thereby determining the minimum number of sub-segments required for the robot to hold the smallest diameter pipe in a misaligned position .

[0093] In order to enable the dislocation pipe holding body to dislocation hold the outer pipe in a circle, it is only necessary to meet the requirement that the robot can hold the pipe with the smallest diameter in a circle without structural interference, that is, the minimum number of sub-segments required for the robot to dislocation hold the pipe with the smallest diameter The thickness t1 of the left and right sides of the rigid sub-body and the width T of the rigid sub-body satisfy equation (5):

[0094] (5)

[0095] This formula has a certain margin. Combined with t2≤2t1, t3≥2t2 and 2t1<t3≤(T-2t1) / 2 (preferably, t2=2t1, t3=2t2=4t1, and T>2t1+2t3), the wall thickness t1 on the left and right sides of the rigid sub-body, the thickness t2 of the rigid connecting rod, the width t3 of each hollow area of ​​the rigid sub-body and the width T of the rigid sub-body can be designed and determined.

[0096] 4. Multi-probe layout is used to improve detection efficiency, detection range, detection resolution, detection accuracy, detection applicability, and detection flexibility, realize multi-functional detection, reduce overall detection costs, and reduce or eliminate blind spots.

[0097] Preferably, ultrasonic detection units can also be installed on the left and right sides of the first rigid sub-body and the second rigid sub-body of each sub-segment of the robot. Due to the misalignment between the two rigid sub-bodies of the sub-segment and the misalignment between each sub-segment, the ultrasonic probes can be arranged in a diversified manner to achieve large-scale multi-area detection, or detect defects in the same area from different angles. If the probes are to be arranged more densely, the ultrasonic probes can be installed on the same side of the first rigid sub-body and the second rigid sub-body of each sub-segment of the misaligned pipe holding body. At this time, the lateral spacing of each ultrasonic probe is the wall thickness t1 on the left and right sides of the rigid sub-body. If the probes are to be arranged more sparsely, the ultrasonic probes can be installed on the same side of the first rigid sub-body or the second rigid sub-body every m sub-segments. At this time, the lateral spacing of each ultrasonic probe is (2m+2)t1. Of course, the ultrasonic probes do not necessarily need to be arranged equidistantly, nor do they necessarily need to be installed on the same side. The arrangement and layout of the ultrasonic probes can be optimized through algorithms based on the detection object, detection requirements, ultrasonic probe characteristics, etc. For example, the ultrasonic probes can be installed more densely on the first few sub-segments and more sparsely on the last few sub-segments. For example, when only specific areas within the coverage area of ​​the robot's staggered pipe holding need to be inspected, ultrasonic probes can be installed on certain sub-segments above or near these specific areas.

[0098] When the number of ultrasonic probes or the coverage area of ​​the dislocation pipe holding needs to be increased, the number of sub-segments N or the number of pipe holding circles n of the dislocation pipe holding body can be increased as required. In order to be able to install ultrasonic probes on the rigid sub-body and avoid structural interference when the robot dislocation pipe holding, formula (5) is further rewritten as:

[0099] (6)

[0100] Where d is the lateral distance required to install the ultrasound probe.

[0101] In addition, the characteristics of the ultrasonic probe can be selected according to different detection requirements. The robot's multi-probe system can be composed of a variety of different ultrasonic probes and can also integrate a variety of ultrasonic detection technologies.

[0102] 5. Motor control design.

[0103] The speed of the first hub motor and the second hub motor is controlled to keep the speed of the two the same during the robot's pipe-holding movement to prevent the robot from being pulled and damaged due to different speeds.

[0104] The winding motor uses a servo motor, and during the robot's pipe-holding movement, the change in the servo motor torque is reflected by real-time monitoring of the change in the servo motor current. This is reflected in:

[0105] ① When the servo motor current increases, that is, the torque increases, it means that the robot encounters a raised obstacle such as rust or attachments. At this time, the winding motor is controlled in real time to release a certain length of rope to restore the torque to prevent excessive torque from damaging the robot and the winding motor. When the raised obstacle becomes smaller or the robot crosses the obstacle, the servo motor current decreases, and the winding motor is controlled in real time to tighten a certain length of rope to maintain the torque.

[0106] ② When the servo motor current becomes smaller, that is, the torque becomes smaller, it means that the robot encounters a recessed obstacle such as a pit. At this time, the winding motor is controlled in real time to tighten a certain length of rope to restore the torque to prevent the robot from detaching from the pipe surface and affecting the stable and uniform pipe-holding adsorption movement. When the recessed obstacle becomes smaller (for example, the pit becomes shallower) or the robot crosses the recessed obstacle, the servo motor current becomes larger, and the winding motor is controlled in real time to release a certain length of rope to maintain the torque.

[0107] 6. Design of driven wheel unit.

[0108] Preferably, in order to further simplify the robot, reduce energy consumption and save costs, the layout of the driven wheel units can be reasonably optimized, such as installing a driven wheel unit for each offset pipe-holding main body sub-segment to reduce the number of driven wheel units and reduce the resistance encountered by the robot during pipe-holding movement, thereby reducing the driving force required for the robot.

[0109] 7. Design of multiple robots holding adjacent pipes.

[0110] When the pipelines to be inspected are adjacent, in order to further improve the automation and operating efficiency of the robot, three or more multi-diameter dislocation pipe-holding wall-climbing robots for external pipeline ultrasonic inspection can be spliced ​​end to end to achieve the automatic movement of the spliced ​​robot from the current pipeline to the adjacent pipeline and hold it tightly. In order to achieve automatic reset and retention after the rope is lengthened when the robot is bent, a spring can be installed between the two adjacent holes in front and behind where the rope passes. At the same time, when the robot automatically resets and holds the state, the rope is tightened and the spring is in a compressed state, but the robot is balanced.

[0111] For example, Fig.13 As shown, a first robot without a rear driving wheel unit, a second robot without a front driving wheel unit and a rear driving wheel unit, and a third robot without a front driving wheel unit are spliced ​​end to end in a staggered manner to form a fourth robot. At this time, the winding motors of the first robot and the second robot are respectively fixed on their respective last sub-segments, and the rope of the second robot also passes through the bottom of the second rigid sub-body of the last sub-segment of the first robot, and the rope of the third robot also passes through the bottom of the second rigid sub-body of the last sub-segment of the second robot. At the same time, no rigid connecting rod is assembled between the two sub-segments at the joints of the first robot and the second robot, and the second robot and the third robot.

[0112] When the current pipeline is inspected and the fourth robot needs to be moved to the adjacent pipeline, the winding motor of the first robot is first used to lengthen its own wire rope, so that the first robot automatically resets to the straightened state and maintains it under the action of the spring, and then the winding motor of the second robot is controlled to lengthen its wire rope, so that the second robot automatically resets to the straightened state and maintains it under the action of the spring, and finally the side of the driven wheel unit of the fully straightened first robot is close to the adjacent pipeline, such as Fig.14 As shown; then the winding motor of the first robot contracts its own wire rope but does not tighten it, so that the first robot can hold the adjacent pipe, and then the winding motor of the third robot is controlled to appropriately lengthen its wire rope and it still holds the current pipe, and at the same time the winding motor of the first robot is controlled to tighten its own wire rope to hold the adjacent pipe, and then the winding motor of the third robot is continued to be controlled to lengthen its wire rope, so that the third robot automatically resets to the straightened state and maintains it under the action of the spring, as shown in FIG. Fig.15 , Fig.16 Finally, the winding motor of the second robot and the winding motor of the third robot are controlled in turn to tighten their respective wire ropes, so that the second robot and the third robot also hold the adjacent pipes tightly, such as Fig.17 shown.

[0113] In this process, the second hub motor of the rear drive wheel unit of the third robot and the first hub motor of the front drive wheel unit of the first robot need to be flexibly controlled so that the fourth robot can climb the pipe on the current pipe or the adjacent pipe to cooperate with the robot to detach and hold the pipe, thereby avoiding collision and reverse bending of the robot with the pipe when the robot is gradually straightened or bent, and also avoiding the first robot being unable to hold the adjacent pipe due to too few sub-segments close to the adjacent pipe. In addition, in this process, the ropes of the first robot, the second robot and the third robot are always in a taut state, and the first robot, the second robot and the third robot do not necessarily need to be completely reset to the straight state, but can also be reset to a slightly bent state and maintained, and the dislocated pipe holding body of the second robot needs to be long enough to ensure that the first robot has enough sub-segments to hold the adjacent pipe when it approaches the adjacent pipe.

[0114] The operation process of the multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing provided by the present invention is as follows:

[0115] Driven by the winding motor 14, the winding drum 15 rotates with the rotating shaft of the winding motor 14 to tighten the wire rope 16. Since the rigid sub-body, the rigid connecting rod, the front wheel connecting member 5 and the rear wheel connecting compartment 10 are hinged and staggered by pins, they can rotate relative to each other at the hinge, so that under the action of the wire rope 16, the robot is staggered and bent toward one side of the wire rope 16, and the tighter the wire rope 16 is, the greater the degree of staggered bending of the robot.

[0116] More specifically, first determine the ultrasonic probe and its arrangement layout according to the detection requirements, and design the robot's dislocation pipe holding body. First design the shape of the rigid sub-body, then determine the parameters of the rigid sub-body and rigid connecting rod in the dislocation pipe holding body according to the outer diameter range of the pipe to be detected and the installation space of the ultrasonic probe, and then design the front drive wheel unit, driven wheel unit, rear drive wheel unit, pipe holding drive unit and ultrasonic detection unit. Then determine the number of sub-segments N of the dislocation pipe holding body according to the diameter of the pipe to be detected and the detection requirements, and the layout of the driven wheel unit can also be reasonably optimized. Finally, the robot is manufactured and assembled.

[0117] When performing misaligned pipe holding and circumferential pipe climbing detection, the robot end in a straightened state can be grasped by tools such as drones, and the robot can be transported to the vicinity of the pipe to be detected, and the side of the robot with the driven wheel unit is close to the pipe, and then the circuit board in the rear wheel connection compartment 10 controls the drive winding motor 14, tightens the wire rope 16, gradually increases the misaligned bending degree of the robot, and makes the robot start to hold the pipe, and at the same time controls the tool to cooperate with the robot's pipe holding movement, and releases the robot at the right time, and finally makes the robot's first hub motor 7, second hub motor 13 and multiple driven wheels 9 closely fit the outer surface of the pipe, and the tighter the wire rope 16 is, the greater the fit between the robot and the outer surface of the pipe, the more stable the robot's pipe holding adsorption, and the more stable the circumferential pipe climbing movement. Then the circuit board in the rear wheel connection compartment 10 controls the first hub motor 7, the second hub motor 13 and the ultrasonic probe 19, so that the robot can perform stable circumferential pipe climbing movement while performing ultrasonic detection on the pipe. After inspecting the current area, stop the robot's movement and ultrasonic inspection, loosen the rope 16 but keep the robot on the pipe. At this time, the robot can be moved to other areas to be inspected on the current inspection pipe by tools, and then the robot can hold the pipe tightly to perform circumferential pipe climbing inspection.

[0118] After the inspection is completed, the robot's movement and ultrasonic inspection are stopped, the wire rope 16 is loosened, the robot is retracted, and the robot can be split into multiple parts according to different numbers of sub-segments for storage, transportation, and subsequent assembly and use. When the number of sub-segments N of the staggered pipe holding body required in the future changes, the sub-segments can be easily increased or decreased after the wire rope 16 is removed, and the driven wheel unit can also be easily increased or decreased.

[0119] The above is only a preferred embodiment of the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing, characterized in that: It includes a dislocated pipe holding body, a front driving wheel unit, a driven wheel unit, a rear driving wheel unit, a pipe holding drive unit and an ultrasonic detection unit; The staggered pipe holding body is composed of a plurality of sub-segments connected in a staggered manner in sequence, and each sub-segment includes a first rigid sub-body, a second rigid sub-body, a first rigid connecting rod, and a second rigid connecting rod; the first rigid sub-body and the second rigid sub-body are arranged in a staggered mirror image and are hinged to form an inverted V-shaped structure of the sub-segment; the first rigid connecting rod and the second rigid connecting rod stagger the inverted V-shaped structures of the front and rear sub-segments, and the two inverted V-shaped structures are staggered and hinged to form an inverted W-shaped structure through adjacent sub-bodies; The front driving wheel unit has a first wheel hub motor, which is staggered and hinged with the first rigid sub-body at the front end of the staggered tube holding body; the rear driving wheel unit has a second wheel hub motor, which is staggered and hinged with the second rigid sub-body at the rear end of the staggered tube holding body; the driven wheel unit is hinged at the bottom of the second rigid sub-body; The pipe holding drive unit comprises a winding motor, a winding drum and a wire rope; the winding motor is fixed on the rear driving wheel unit, the winding drum is fixed on the rotating shaft of the winding motor, one end of the wire rope is fixed on the winding drum, and the other end passes through the rear driving wheel unit, each sub-segment of the dislocated pipe holding body and the bottom of the front driving wheel unit in sequence, and then passes back to the winding drum in sequence and is fixed; The ultrasonic detection unit is fixed on the front driving wheel unit, and ultrasonic detection of the external pipeline is realized by an ultrasonic probe; By driving the winding motor to rotate the winding drum to tighten the rope, the robot is bent toward one side of the rope and tightly adheres to the outer surface of the pipe; by controlling the two hub motors, the robot is allowed to climb the pipe in a circumferential direction.

2. The multi-diameter dislocation pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 1 is characterized in that: The first rigid sub-body is a frame-type structure, with a concave structure at the top and bottom, equal wall thickness on the left and right sides, and transverse through holes at the upper and lower ends of the left and right sides, a vertical support column is provided in the middle, dividing the first rigid sub-body into left and right hollow areas, and transverse through holes are provided in the middle of the left and right sides of the first rigid sub-body and the middle of the support column; the second rigid sub-body is hinged to the first rigid sub-body through the upper transverse through holes on the left and right sides, the right inner wall of the first rigid sub-body is in contact with the right outer wall of the second rigid sub-body, and the left outer wall of the first rigid sub-body is in contact with the left inner wall of the second rigid sub-body, and the two are laterally staggered by a distance of wall thickness.

3. The multi-diameter dislocation pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 2 is characterized in that: The first rigid link has through holes at both ends, which are hinged to the middle transverse through holes of the first rigid sub-body of the front and rear sub-segments, and are located in the left hollow area of ​​the first rigid sub-body and the second rigid sub-body; the second rigid link has through holes at both ends, which are hinged to the middle transverse through holes of the second rigid sub-body of the front and rear sub-segments, and are located in the right hollow area of ​​the first rigid sub-body and the second rigid sub-body.

4. The multi-diameter dislocation pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 3 is characterized in that: The front drive wheel unit includes a front wheel connecting member, which is in a U-shaped structure lying flat forward. Transverse through holes are provided at the front ends on both left and right sides for a first threaded fixing shaft for fixedly installing a first hub motor. A transverse through hole is provided at the lower end of the part connecting the rear ends on both left and right sides in the U-shaped structure, and is hinged to the lower transverse through holes on both left and right sides of the first rigid sub-body at the frontmost end of the misaligned pipe-holding main body; the part connecting the left and right sides in the U-shaped structure is hollowed out from both left and right sides to the middle to form a vertical support column. A transverse through hole is provided in the middle of the support column. By adding a second rigid link, the through holes at both ends thereof are respectively hinged to the transverse through hole of the support column of the front wheel connecting member and the middle transverse through hole of the second rigid sub-body at the frontmost end of the misaligned pipe-holding main body.

5. The multi-diameter dislocation pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 3 is characterized in that: The rear drive wheel unit includes a rear wheel connecting bin, which is composed of an L-shaped structure and a U-shaped structure lying flat backward; transverse through holes are provided at the rear ends on both left and right sides of the U-shaped structure for a second threaded fixing shaft for fixedly installing a second hub motor. A transverse through hole is provided at the lower end of the part connecting the front ends on both left and right sides in the U-shaped structure, and is hinged to the lower transverse through holes on both left and right sides of the second rigid sub-body at the rearmost end of the misaligned pipe-holding main body; the L-shaped structure is a hollow bin body for placing a circuit board arranged above and behind the U-shaped structure; the part connecting the left and right sides in the U-shaped structure is hollowed out from both left and right sides to the middle to form a vertical support column. A transverse through hole is provided in the middle of the support column. The through holes at both ends of the first rigid link at the rearmost end of the misaligned pipe-holding main body are respectively hinged to the transverse through hole of the support column of the rear wheel connecting bin and the middle transverse through hole of the first rigid sub-body at the rearmost end of the misaligned pipe-holding main body, and the second rigid link is removed from the sub-segment at the rearmost end of the misaligned pipe-holding main body.

6. The multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 3 is characterized in that: The front and rear sub-segments of the misaligned pipe-holding main body are misaligned and connected without structural interference, and need to satisfy t2≤2t1, t3≥2t2, and 2t1<t3≤(T - 2t1) / 2, where t1 is the wall thickness on both left and right sides of the rigid sub-body, t2 is the thickness of the rigid link, t3 is the width of each hollow area of the rigid sub-body, and T is the width of the rigid sub-body; there is no structural interference between the driven wheel units of the front and rear sub-segments of the misaligned pipe-holding main body when the robot misaligns and holds the pipe, and it needs to satisfy t4<2t1, where t4 is the thickness of the driven wheel.

7. The multi-diameter dislocation pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 6 is characterized in that: The minimum number of sub-segments of the dislocation pipe holding body is determined according to the pipe diameter. The dislocation pipe holding body holds the outer pipe for at least one circle. When the dislocation pipe holding body holds the outer pipe for one circle, the pipe diameter D and the minimum number of sub-segments N of the dislocation pipe holding body are equal. min satisfy , where H is the distance from the center of the horizontal through hole in the middle of the rigid sub-body to the ground when the robot is placed flat on the ground, and C is the center distance of the through holes at both ends of the rigid connecting rod. It is an intermediate parameter. When the pipe diameter D is determined, it is first calculated , then Round up to get the minimum number of sub-segments N min ; When the staggered pipe holding body is required to hold the outer pipe n times, Multiply by n and round up to get the number N of sub-segments of the misaligned pipe body.

8. The multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 7 is characterized in that: The parameter design of the misaligned pipe-holding main body is specifically as follows: The robot has a minimum applicable pipe diameter D min , the robot is suitable for pipe diameter D ≥ D min ; When the robot holds the pipe in a misaligned position, the pipe diameter D, the distance h from the center of the transverse through hole at the lower end of the rigid sub-body to the ground when the robot is placed flat on the ground, the center distance L between the transverse through hole at the upper end and the transverse through hole at the lower end of the rigid sub-body, and the angle between the straight line connecting the transverse through hole at the upper end and the transverse through hole at the lower end of the first rigid sub-body and the straight line connecting the transverse through hole at the upper end and the transverse through hole at the lower end of the second rigid sub-body in the same sub-segment , the angle between the straight line connecting the upper and lower transverse through holes of the second rigid sub-body and the straight line connecting the upper and lower transverse through holes of the first rigid sub-body of the next sub-segment Satisfying formula (1): (1) L. , The center distance C of the through holes at both ends of the rigid connecting rod satisfies formula (2): (2) The degree of bending when the robot holds the pipe in a misaligned position depends on the outer diameter of the pipe. Minimum value of and The maximum value of Determined by the structure of the robot, when the robot reaches the limit of bending, , , D=D min ; First design the rigid sub-body shape and determine when the robot reaches the limit bending degree. and And h, and then determine the range of pipe diameter D applicable to the robot according to the different outer diameters of the various pipes to be detected. , D=D min Substitute and h into formula (1) to obtain L; or, first design the rigid subbody shape and L, and then calculate D = D using formula (1) min , and verify D min Is it less than or equal to the minimum pipe diameter to be tested? If not, modify L until it is satisfied. , Substituting L into formula (2) to obtain C; the calculation formula for H is , where the robot is flat on the ground , The value of is determined when the rigid subbody shape is designed; According to D=D min , H and C to calculate the minimum number of sub-segments required for the robot to hold the minimum diameter pipe in a misaligned manner , , t1 and T satisfy ; Then, combined with t2≤2t1, t3≥2t2 and 2t1<t3≤(T-2t1) / 2, determine the wall thickness t1 on the left and right sides of the rigid sub-body, the thickness t2 of the rigid connecting rod, the width t3 of each hollow area of ​​the rigid sub-body and the width T of the rigid sub-body.

9. The multi-diameter dislocation pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 1 is characterized in that: The wire winding motor adopts a servo motor, and the change of the torque of the servo motor is reflected by real-time monitoring of the change of the current of the servo motor: When the current of the servo motor becomes larger, it indicates that the robot encounters a raised obstacle, and the wire winding motor is controlled to release the wire rope to restore the torque. When the raised obstacle becomes smaller or the robot crosses the raised obstacle, the current of the servo motor becomes smaller, and the wire winding motor is controlled to tighten the wire rope to maintain the torque; When the current of the servo motor becomes smaller, it indicates that the robot encounters a sunken obstacle, and the wire winding motor is controlled to tighten the wire rope to restore the torque. When the sunken obstacle becomes smaller or the robot crosses the sunken obstacle, the current of the servo motor becomes larger, and the wire winding motor is controlled to release the wire rope to maintain the torque.

10. The multi-diameter dislocated pipe-holding wall-climbing robot for external pipeline ultrasonic testing according to claim 1 is characterized in that: By splicing three or more robots head to tail in a staggered manner, the spliced ​​robots can automatically move from the current pipe to the adjacent pipe and hold it tightly; by installing a spring between the two adjacent holes in front and behind where the wire rope passes, the robot can automatically reset and hold the wire rope after it is lengthened when it is bent; During the splicing process, the robot at the front end removes the rear drive wheel unit and fixes the winding motor on the last sub-segment, the robot in the middle part removes the front drive wheel unit and the rear drive wheel unit and fixes the winding motor on the last sub-segment, and the robot at the rear end removes the front drive wheel unit. The rope of the rear robot passes through the bottom of the second rigid sub-body of the last sub-segment of the front robot, and no rigid connecting rod is installed between the two sub-segments at the splicing point.

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