Crawling robot for inline inspection and working method thereof

Abstract

The present invention relates to the technical field of automatic non-destructive inspection. Disclosed are a crawling robot for inline inspection and a working method thereof. A driving motor, a gyroscope, an air cylinder and a control unit are arranged in a body; a pair of front driving wheels and a pair of rear driven wheels are arranged on the lower portion of the body, and the front driving wheels and the rear driven wheels are all permanent magnetic wheels; the pair of front driving wheels are connected to the driving motor by means of a transmission shaft and a differential mechanism, respectively; the air cylinder is connected to a phased array testing probe by means of a phased array probe support; an electromagnetic thickness measuring probe and an image acquisition device are arranged on the body; and the phased array testing probe, the electromagnetic thickness measuring probe, the image acquisition device, the driving motor, the gyroscope and the air cylinder are separately connected to the control unit. The present invention involves simple and convenient operation, has high inspection efficiency and complete inspection function, can enable the crawling robot to turn and steer in a narrow space and reach a position inaccessible to humans for inspection, and has good application prospects.

Description

A crawling robot for pipeline inspection and its working method Technical Field

[0001] The present invention belongs to the technical field of automatic non-destructive testing, and in particular relates to a crawling robot for testing inside a pipeline and a working method thereof. Background Art

[0002] Currently, non-destructive testing (NDT) of welds on in-service thermal power pressure pipelines often requires extensive preparatory work, such as scaffolding, excavation, and insulation removal. This is time-consuming, labor-intensive, and high-risk. Some buried pipelines cannot be excavated for NDT due to environmental restrictions, such as crossing rivers. This significantly limits manual testing, posing significant safety risks to production operations and seriously impacting safe and economical operations. Therefore, it is necessary to employ automated NDT technology to remotely inspect the interior of pipelines, eliminating the need for scaffolding, excavation, or insulation removal, and to perform NDT on pipeline welds.

[0003] The inner wall of a thermal power pressure pipeline is curved and has many elbows. When crawling inside the pipeline, the robot must not only perform circumferential and axial curved motions, but also negotiate nearly 90-degree bends. Conventional pipeline inspection robots are unable to navigate these tight spaces while carrying inspection equipment, making it difficult to perform automated nondestructive testing of pipeline inner wall welds in such a confined space.

[0004] Summary of the Invention

[0005] In order to solve the above-mentioned existing problems, the purpose of the present invention is to provide a crawling robot and a working method for detection in pipelines, which have high detection efficiency and complete detection functions, enable the crawling robot to complete cornering and turning in a narrow space, and reach positions that are inaccessible to human power for detection, and have wide applicability.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention discloses a crawling robot for pipeline inspection, comprising a main body, wherein a drive motor, a gyroscope, a cylinder and a control unit are arranged inside the main body; a pair of front drive wheels and a pair of rear driven wheels are arranged at the lower part of the main body, and the front drive wheels and the rear driven wheels are permanent magnet wheels; the pair of front drive wheels are respectively connected to the drive motor via a transmission shaft and a differential mechanism; the cylinder is connected to a phased array detection probe via a phased array probe bracket; an electromagnetic thickness measuring probe and an image acquisition device are provided on the main body; the phased array detection probe, the electromagnetic thickness measuring probe, the image acquisition device, the drive motor, the gyroscope and the cylinder are respectively connected to the control unit.

[0008] Preferably, the magnetism of the front driving wheel is greater than that of the rear driven wheel.

[0009] Preferably, the differential mechanism includes a second bevel gear and a pair of first bevel gears, the pair of first bevel gears are fixedly connected to the front drive wheel and the transmission shaft and are arranged opposite to each other, and the second bevel gears are respectively engaged with the pair of first bevel gears; the second bevel gear is connected to the drive motor through the transmission shaft.

[0010] Preferably, the phased array probe bracket includes a connecting frame and a connecting hinge; one end of the connecting frame is connected to the cylinder and is connected to the body through a plurality of connecting hinges; the connecting frame fixes the phased array detection probe through a plurality of second connecting bolts.

[0011] Further preferably, the connecting frame is connected to a plurality of concave support frames, the concave support frames are connected to a plurality of guide wheels via third connecting bolts, and the plurality of guide wheels are distributed around the phased array detection probe.

[0012] Preferably, a pair of rear driven wheels are connected through a rear driven wheel axle, a square connecting rod is sleeved on the outside of the rear driven wheel axle, a plurality of bearings are provided in the square connecting rod, and the rear driven wheel axle is connected to the plurality of bearings; the square connecting rod is connected to a movable bolt, and the eyelet of the movable bolt is connected to the body through a first connecting bolt; an electromagnetic thickness measuring probe bracket is provided on the square connecting rod, and the electromagnetic thickness measuring probe is detachably connected to the electromagnetic thickness measuring probe bracket.

[0013] Preferably, the main body is further provided with an illumination device and a coupling agent spraying mechanism, the coupling agent spraying mechanism is connected to an external coupling agent delivery system, and the illumination device and the coupling agent spraying mechanism are respectively connected to a control unit.

[0014] Preferably, an electromagnetic thickness measuring board is provided inside the body, which is connected to the electromagnetic thickness measuring probe; the body is connected to a phased array board through a number of hanging ears, which is connected to the phased array detection probe, and the interface of the phased array board is waterproofed.

[0015] Preferably, the image acquisition device is a high-definition camera, and the driving motor is a servo motor.

[0016] The working method of the above-mentioned crawling robot for pipeline detection disclosed in the present invention includes:

[0017] The control unit is connected to the host computer, and the crawling robot enters the pipeline to be inspected. The driving motor drives the front driving wheel to rotate and drives the rear driven wheel to rotate, and moves along the pipeline; the cylinder lifts the phased array detection probe away from the inner wall of the pipeline through the phased array probe bracket; the posture and position of the crawling robot are detected in real time by the gyroscope; the image acquisition device and the lighting device are used to move to the girth weld position, and the cylinder is controlled to drive the phased array probe bracket to adjust the distance between the phased array detection probe and the inner wall of the pipeline; the crawling robot travels around the girth of the girth weld, uses the electromagnetic thickness probe to detect the pipeline wall thickness, uses the image acquisition device to perform macroscopic detection, and uses the phased array detection probe to perform phased array detection; the detection signal is transmitted to the host computer through the control unit, and receives the control instructions from the host computer.

[0018] Compared with the prior art, the present invention has the following beneficial technical effects:

[0019] The present invention discloses a crawling robot for in-pipeline inspection, which utilizes a pair of front drive wheels and a pair of rear driven wheels as a moving tool. The permanent magnet wheels enable the crawling robot to achieve circumferential motion along the girth weld of the pipeline. At the same time, the pair of front drive wheels are driven by a differential mechanism, which enables the crawling robot to complete cornering and steering in a narrow space, thereby improving the control stability of the crawling robot. The phased array probe holder is extended and retracted by a cylinder, so that the phased array probe holder has a certain adaptive force under the action of air pressure after being extended, thereby preventing the probe from being damaged by excessive force, and at the same time ensuring the fit between the probe and the curved surface of the pipeline. The robot is provided with a gyroscope, and the gyroscope module has an integrated attitude solver. In conjunction with the dynamic Kalman filter algorithm, it can accurately output the current attitude of the module in a dynamic environment. The attitude measurement accuracy is 0.05 degrees, and the stability is high. The attitude and position of the robot inside the pipeline can be detected in real time. The crawling robot integrates an electromagnetic thickness gauge probe, an image acquisition device and a phased array detection probe. It can simultaneously complete wall thickness detection, macroscopic detection and phased array detection of pipeline welds. It has high detection efficiency and complete detection functions. It can reach locations inaccessible to human beings through the inner wall of the pipeline for detection and has wide applicability.

[0020] Furthermore, the magnetism of the front driving wheel is greater than that of the rear driven wheel, which not only ensures that the robot has sufficient adsorption force to prevent it from falling from above during circumferential movement, but also avoids the magnetic force of the driven wheel being too large to generate a large adsorption force, which makes the robot unable to complete the turning action in the pipeline.

[0021] Furthermore, the array probe holder's connecting bracket is connected to the cylinder and the body, respectively. This ensures that when the cylinder extends the phased array probe, the probe holder does not rotate due to the action of the connecting hinge, and remains parallel to the weld angle. The combined design of the connecting hinges ensures the extended length of the phased array probe while preventing the probe from being blocked when retracted due to excessive connecting hinges. The phased array detection probe is secured by a number of second connecting bolts, making it easy to adjust the extended length of the phased array probe.

[0022] Furthermore, the guide wheels distributed around the phased array probe can not only ensure good coupling between the probe wedge and the pipe surface during the phased array detection process, but also assist the probe wedge in moving smoothly on the inner wall of the pipe, thereby improving detection efficiency and accuracy.

[0023] Furthermore, the square connecting rod is connected with a movable bolt, and the eye of the movable bolt is connected to the body through a first connecting bolt, so that the distance between the electromagnetic probe and the pipe wall can be adjusted at any time.

[0024] Furthermore, the lighting device can provide a stable light source in the dark space inside the pipeline, making it easier to observe the internal conditions of the pipeline; the coupling agent spraying mechanism can spray coupling agent during detection, thereby improving detection efficiency.

[0025] The working method of the crawling robot for in-pipeline inspection disclosed in the present invention is easy to operate, has high inspection efficiency, and has complete inspection functions. It can enable the crawling robot to complete cornering and steering in a narrow space and reach positions that are inaccessible to human power for inspection, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG1 is a schematic front view of the structure of a crawling robot for in-pipeline inspection according to the present invention;

[0027] FIG2 is a schematic diagram of the structure of the crawling robot for in-pipeline inspection according to the present invention when viewed from above;

[0028] FIG3 is a side view of the structure of a crawling robot for in-pipeline inspection according to the present invention;

[0029] FIG4 is a schematic diagram of the connection structure of the probe bracket and the cylinder of the present invention;

[0030] FIG5 is a physical diagram of the crawling robot in the embodiment;

[0031] FIG6 is a working state diagram of the crawling robot in the embodiment.

[0032] In the figure: 1 is the main body, 2 is the phased array board, 3 is the phased array detection probe, 4 is the phased array probe bracket, 5 is the electromagnetic thickness gauge probe, 6 is the electromagnetic thickness gauge board, 7 is the image acquisition device, 8 is the lighting device, 9 is the front drive wheel, 10 is the rear driven wheel, 11 is the first connecting bolt, 12 is the drive motor, 13 is the gyroscope, 14 is the transmission shaft, 15 is the first bevel gear, 16 is the second bevel gear, 17 is the square connecting rod, 18 is the live bolt, 19 is the nut, 20 is the cylinder, 21 is the hanging ear, 22 is the second connecting bolt, 41 is the connecting frame, 42 is the guide wheel, 43 is the concave support frame, 44 is the connecting hinge, and 45 is the third connecting bolt. DETAILED DESCRIPTION

[0033] The present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments, which are intended to explain the present invention rather than to limit it:

[0034] As shown in Figure 1, a crawling robot for pipeline inspection of the present invention includes a body 1, which is characterized in that a drive motor 12, a gyroscope 13, a cylinder 20 and a control unit are provided inside the body 1; a pair of front drive wheels 9 and a pair of rear driven wheels 10 are provided at the lower part of the body 1, and the front drive wheels 9 and the rear driven wheels 10 are permanent magnet wheels; the pair of front drive wheels 9 are respectively connected to the drive motor 12 through a transmission shaft 14 and a differential mechanism; the cylinder 20 is connected to a phased array detection probe 3 through a phased array probe bracket 4; an electromagnetic thickness measuring probe 5 and an image acquisition device 7 are provided on the body 1; the phased array detection probe 3, the electromagnetic thickness measuring probe 5, the image acquisition device 7, the drive motor 12, the gyroscope 13 and the cylinder 20 are respectively connected to the control unit.

[0035] In a preferred embodiment of the present invention, the magnetism of the front driving wheel 9 is greater than that of the rear driven wheel 10 .

[0036] In a preferred embodiment of the present invention, the differential mechanism includes a second bevel gear 16 and a pair of first bevel gears 15, the pair of first bevel gears 15 are fixedly connected to the front drive wheel 9 and the transmission shaft 14 and are arranged opposite to each other, and the second bevel gear 16 is respectively engaged with the pair of first bevel gears 15; the second bevel gear 16 is connected to the drive motor 12 through the transmission shaft.

[0037] In a preferred embodiment of the present invention, the phased array probe bracket 4 includes a connecting frame 41 and connecting hinges 44. One end of the connecting frame 41 is connected to the cylinder 20 and is connected to the body 1 via a plurality of connecting hinges 44. The connecting frame 41 secures the phased array detection probe 3 via a plurality of second connecting bolts 22. Preferably, the connecting frame 41 is connected to a plurality of concave support frames 43, which are connected to a plurality of guide wheels 42 via third connecting bolts 45. The guide wheels 42 are distributed around the phased array detection probe 3.

[0038] In a preferred embodiment of the present invention, a pair of rear driven wheels 10 are connected by a rear driven wheel axle, a square connecting rod 17 is sleeved on the outside of the rear driven wheel axle, a plurality of bearings are provided in the square connecting rod 17, and the rear driven wheel axle is connected to the plurality of bearings; the square connecting rod 17 is connected to a movable bolt 18, and the eyelet of the movable bolt 18 is connected to the body 1 through the first connecting bolt 11; an electromagnetic thickness measuring probe bracket is provided on the square connecting rod 17, and the electromagnetic thickness measuring probe 5 is detachably connected to the electromagnetic thickness measuring probe bracket.

[0039] In a preferred embodiment of the present invention, the main body 1 is further provided with an illumination device 8 and a coupling agent spraying mechanism, the coupling agent spraying mechanism is connected to an external coupling agent delivery system, and the illumination device 8 and the coupling agent spraying mechanism are respectively connected to a control unit.

[0040] In a preferred embodiment of the present invention, an electromagnetic thickness measuring board 6 is provided inside the body 1, and the electromagnetic thickness measuring board 6 is connected to the electromagnetic thickness measuring probe 5; the body 1 is connected to a phased array board 2 via a plurality of hanging ears 21, and the phased array board 2 is connected to the phased array detection probe 3. The interface of the phased array board 2 is waterproofed.

[0041] In a preferred embodiment of the present invention, the image acquisition device 7 is a high-definition camera, and the driving motor 12 is a servo motor.

[0042] The working method of the above crawling robot for pipeline inspection is as follows:

[0043] The control unit is connected to the host computer, and the crawling robot enters the pipeline to be inspected. The driving motor 12 drives the front driving wheel 9 to rotate and drives the rear driven wheel 10 to rotate, and moves along the pipeline; the cylinder 20 lifts the phased array detection probe 3 away from the inner wall of the pipeline through the phased array probe bracket 4; the posture and position of the crawling robot are detected in real time by the gyroscope 13; the image acquisition device 7 and the lighting device 8 are used to move to the girth weld position, and the cylinder 20 is controlled to drive the phased array probe bracket 4 to adjust the distance between the phased array detection probe 3 and the inner wall of the pipeline; the crawling robot travels one circle along the circumference of the girth weld, uses the electromagnetic thickness measuring probe 5 to detect the pipeline wall thickness, uses the image acquisition device 7 to perform macroscopic detection, and uses the phased array detection probe 3 to perform phased array detection; the detection signal is transmitted to the host computer through the control unit, and receives the control instructions from the host computer.

[0044] The present invention will be further explained below with a specific embodiment:

[0045] As shown in Figure 5, which is a physical picture of the crawling robot of the present invention, in this embodiment, the phased array detection probe adopts a 32-group self-transmitting and self-receiving phased array probe with a probe specification of 5L32-0.6x10; the supporting wedge material is polystyrene, and the wedge angle is 37°; the electromagnetic ultrasonic thickness measurement probe 5 is a ZKCX-EMAT probe with a probe diameter of Ф25mm, a lift-off height of 3mm, and a resolution of 0.01mm; the image acquisition device 7 adopts a high-definition camera with a resolution of 3.0MP.

[0046] The overall dimensions of the robot are: 279mm×200mm×165mm (length×width×height). The drive motor 12 adopts a TBSM52-20B33 servo motor, the gyroscope 13 is a WT901C485 from Witt Intelligent, and the control unit adopts an industrial PC with a Windows 10 operating system.

[0047] The four mounting ears 21 of the phased array board 2 are connected to the main body 1 using M5 bolts. The swing bolt 18 is M10×40, and the nut 19 is M10×1.25. The first connecting bolt 11 uses an M12 external hexagonal stud; there are two second connecting bolts 22, each using an M3 internal hexagonal stud; and there are four third connecting bolts 45, each using an M3 internal hexagonal stud. The phased array board 2 adopts a compact L-shaped design and is mounted upside down on the main body 1, effectively saving space while ensuring the integrity of the phased array detection system.

[0048] Before starting the inspection, connect the main body 1, phased array probe 3, phased array board 2, electromagnetic thickness measurement board 6, electromagnetic thickness measurement probe 5, and high-definition camera to form a crawling robot inspection system, and connect the crawling robot inspection system to the industrial PC via a data cable and a power cable.

[0049] As shown in Figure 6, during inspection, the control cylinder 20 drives the phased array inspection probe 3 in a lifted position. The industrial PC controls the main body 1 to advance axially along the pipe wall. When the high-definition camera, aided by the lighting device 8, detects a weld, the main body 1's posture is adjusted from axial to circumferential motion, aligning the main body 1's movement with the weld. The control cylinder 20 extends the phased array inspection probe 3. Under the action of the cylinder 20, the phased array inspection probe 3 is tightly attached to the pipe wall. A water pump begins spraying water as a coupling agent into the area to be inspected. The phased array inspection software in the industrial PC confirms that the phased array inspection probe 3 is effectively coupled to the pipe wall surface. The industrial PC controls the main body 1 to begin circumferential motion. With the assistance of the guide wheel 42, the phased array inspection probe 3 moves smoothly against the wall, performing phased array inspection of the weld. Simultaneously, during this motion, the electromagnetic thickness gauge 5 at the rear of the main body 1 measures the wall thickness. After the main body 1 circles the weld, the automatic inspection of the pipe inner wall weld is complete. The industrial PC controls the cylinder to retract the phased array inspection probe 3, adjusts the robot's motion from circumferential to axial, and continues to control its movement into the pipe. The industrial PC displays a visual interface, allowing real-time observation of the robot's trajectory and posture, as well as the high-definition camera's macroscopic inspection image. Repeating these steps completes the automated inspection of welds inside the pipe.

[0050] The above description is merely an embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention, or equivalent structures or equivalent process transformations made using the contents of the present invention's description and drawings, or direct or indirect applications in other related technical fields, should all be covered by the scope of protection of the present invention.

Claims

1. A crawling robot for detecting inside a pipeline, comprising a body (1), characterized in that: A driving motor (12), a gyroscope (13), a cylinder (20) and a control unit are provided inside the body (1); a pair of front driving wheels (9) and a pair of rear driven wheels (10) are provided at the lower part of the body (1), and the front driving wheels (9) and the rear driven wheels (10) are both permanent magnet wheels; the pair of front driving wheels (9) are respectively connected to the driving motor (12) via a transmission shaft (14) and a differential mechanism; the cylinder (20) is connected to a phased array detection probe (3) via a phased array probe bracket (4); an electromagnetic thickness measuring probe (5) and an image acquisition device (7) are provided on the body (1); the phased array detection probe (3), the electromagnetic thickness measuring probe (5), the image acquisition device (7), the driving motor (12), the gyroscope (13) and the cylinder (20) are respectively connected to the control unit.

2. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: The magnetism of the front driving wheel (9) is greater than that of the rear driven wheel (10).

3. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: The differential mechanism comprises a second bevel gear (16) and a pair of first bevel gears (15), wherein the pair of first bevel gears (15) are fixedly connected to the front drive wheel (9) and the transmission shaft (14) and are arranged opposite to each other, and the second bevel gears (16) are respectively meshed with the pair of first bevel gears (15); and the second bevel gears (16) are connected to the drive motor (12) via the transmission shaft.

4. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: The phased array probe bracket (4) comprises a connecting frame (41) and a connecting hinge (44); one end of the connecting frame (41) is connected to the cylinder (20) and is connected to the body (1) via a plurality of connecting hinges (44); the connecting frame (41) fixes the phased array detection probe (3) via a plurality of second connecting bolts (22).

5. The crawling robot for in-pipeline inspection according to claim 4, characterized in that: The connecting frame (41) is connected to a plurality of concave support frames (43), and the concave support frames (43) are connected to a plurality of guide wheels (42) via third connecting bolts (45). The plurality of guide wheels (42) are distributed around the phased array detection probe (3).

6. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: A pair of rear driven wheels (10) are connected through a rear driven wheel shaft. A square connecting rod (17) is sleeved on the outside of the rear driven wheel shaft. A plurality of bearings are arranged in the square connecting rod (17). The rear driven wheel shaft is connected to the plurality of bearings. The square connecting rod (17) is connected to a movable bolt (18). The eyelet of the movable bolt (18) is connected to the body (1) through a first connecting bolt (11). An electromagnetic thickness measuring probe bracket is provided on the square connecting rod (17). The electromagnetic thickness measuring probe (5) is detachably connected to the electromagnetic thickness measuring probe bracket.

7. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: The main body (1) is also provided with an illumination device (8) and a coupling agent spraying mechanism, the coupling agent spraying mechanism is connected to an external coupling agent delivery system, and the illumination device (8) and the coupling agent spraying mechanism are respectively connected to a control unit.

8. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: An electromagnetic thickness measuring board (6) is provided inside the body (1), and the electromagnetic thickness measuring board (6) is connected to an electromagnetic thickness measuring probe (5); the body (1) is connected to a phased array board (2) via a plurality of hanging ears (21), and the phased array board (2) is connected to a phased array detection probe (3), and the interface of the phased array board (2) is waterproofed.

9. The crawling robot for in-pipeline inspection according to claim 1, characterized in that: The image acquisition device (7) is a high-definition camera, and the driving motor (12) is a servo motor.

10. The working method of the crawling robot for in-pipeline inspection according to claims 1 to 9, characterized in that: include: The control unit is connected to a host computer, and the crawling robot enters the pipeline to be inspected. The driving motor (12) drives the front driving wheel (9) to rotate and drives the rear driven wheel (10) to rotate, and the robot travels along the pipeline; the cylinder (20) lifts the phased array detection probe (3) away from the inner wall of the pipeline through the phased array probe bracket (4); the posture and position of the crawling robot are detected in real time by the gyroscope (13); the robot travels to the girth weld position by using the image acquisition device (7) and the lighting device (8), and controls the cylinder (20) to drive the phased array probe bracket (4) to adjust the distance between the phased array detection probe (3) and the inner wall of the pipeline; the robot travels one circle along the circumference of the girth weld, performs pipeline wall thickness detection by using the electromagnetic thickness measuring probe (5), performs macroscopic detection by using the image acquisition device (7), and performs phased array detection by using the phased array detection probe (3); the detection signal is transmitted to the host computer through the control unit, and the robot receives control instructions from the host computer.

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