Annular surface outer pipeline weld joint surface grinding device and grinding quality detection method thereof

Abstract

The invention discloses a ring surface outer pipeline welding seam surface grinding device and a grinding quality detection method thereof, and relates to the technical field of pipeline grinding, the ring surface outer pipeline welding seam surface grinding device comprises a grinding unit, a holding arm unit and a motion control system, the grinding unit is composed of a binocular stereoscopic vision system and a flexible grinding head device, the arm holding unit is composed of a pressure sensor set, an electromagnetic adsorption device and a mechanical arm set, and the motion control system is composed of a driving box, a wheel set and a frame set. The electromagnetic adsorption device is adopted, during work, the binocular stereoscopic vision detection system determines the range of a to-be-polished area, the controller drives the polishing device to move, the induction type pressure sensor feeds back collected pressure signals of an electromagnet and the outer wall of a pipeline to the control module, and the magnitude of electromagnetic force is controlled by changing the current of a coil; in addition, due to the fact that the polishing device is of a semi-open structure through the hinge device, multi-dimensional safe and efficient polishing operation is achieved by means of the electromagnetic force adjustable adsorption device.

Description

Technical Field

[0001] The invention relates to the technical field of pipeline grinding, and in particular to a ring surface outer pipeline weld surface grinding device for cleaning an oxide layer on the outer wall of a superheated steam pipeline in a power plant and a control method thereof. Background Art

[0002] Power plants use coal to generate high-temperature, high-pressure superheated steam to generate electricity. The pipes used to transport this high-temperature, high-pressure superheated steam often produce an oxide layer on the outer wall of the pipe because of the high-temperature, high-pressure superheated steam. The pipes in thermal power plants are connected by welding. In order to avoid safety hazards, thermal power plants need to regularly inspect the pipe welds and clean the oxide layer in the 400mm area around the welds. The oxide layer around the pipe welds is formed by high-temperature, high-pressure steam and is difficult to remove. Generally, workers use handheld grinders to remove it, which is labor-intensive, low-grinding efficiency, high cost, and long grinding time. Workers use handheld grinders to grind, which is not only labor-intensive, but also has safety hazards. The present invention makes improvements on this and designs an automatic pipeline grinding device to solve the problem of the oxide layer of the pipeline, improve the grinding efficiency, and reduce labor costs. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a ring-shaped outer pipe weld surface grinding device and a control method thereof for cleaning the oxide layer on the outer wall of the superheated steam pipe of a power plant. The device uses an electromagnetically controlled claw clamp, which can move in two dimensions: the axial direction of the pipeline and the circumferential direction of the pipeline to be polished. A binocular camera is used for visual positioning and detection of weld points to realize the application of grinding work scenarios of pipes of different diameters.

[0004] The purpose of the present invention can be achieved through the following technical solutions: A device for grinding the weld surface of an annular outer pipe, comprising a motion control system for controlling the motion of a grinding unit and an arm unit; A grinding unit, used for identifying the weld on the pipeline surface and grinding the oxide layer around the entire pipeline, wherein the grinding unit is arranged on the motion control system; The polishing unit includes a binocular stereo vision system for collecting images of the pipeline to obtain the target area to be polished; and also includes a flexible polishing head device for polishing the pipeline surface at multiple angles; The arm unit is used for fixing the pipeline, and the arm unit is arranged on the motion control system.

[0005] As a further solution of the present invention: the binocular stereo vision system includes an infrared ranging sensor and a binocular camera; the flexible grinding head device includes a flexible grinding head, a crank rocker mechanism, and the flexible grinding head and the crank rocker mechanism are connected by a sleeve, and a spring runs through the sleeve.

[0006] As a further solution of the present invention: the binocular camera is installed on the inner side of the drive box to monitor the displacement of the flexible grinding head and the target grinding area; the infrared ranging sensor and the binocular camera are installed in the same straight line to detect the condition of the pipeline area to be polished and the grinding quality, and feed back the signal to the controller to adjust the working progress of the flexible grinding head device through the swing of the crank rocker mechanism.

[0007] As a further solution of the present invention: the arm holding unit is composed of a pressure sensor group, an electromagnetic adsorption device and a mechanical arm; The electromagnetic adsorption device comprises an armature, a yoke, and a copper coil. The armature runs through the center of the copper coil. After the yoke is added, the armature and the yoke form a closed magnetic circuit. The fixed cover plate and the sealant seal the entire device. A first inductive pressure sensor, a second inductive pressure sensor, a third inductive pressure sensor and a fourth inductive pressure sensor are installed on the side of the electromagnetic adsorption device, which are used to detect the pressure change between the electromagnetic adsorption device and the external pipeline. The movement of the magnetic core caused by the pressure change will change the sensor induced current, and the current signal is converted into a usable signal and fed to the controller. The angle of the mechanical arm is adjusted by controlling the size of the electromagnetic adsorption force, so that the arm unit and the external pipeline are opened and closed.

[0008] As a further solution of the present invention: the mechanical arm group consists of a first inner arm, a second inner arm, a first outer arm, a second outer arm, a first lasso, a second lasso, a first pulley and a second pulley; the first inner arm and the second inner arm are connected to the drive box by a hinge, the first inner arm is connected to the first outer arm by a hinge, the second inner arm is connected to the second outer arm by a hinge, the first pulley is installed in a U-shaped groove on the first inner arm, the second pulley is installed in a U-shaped groove on the second inner arm, the first lasso and the second lasso are distributed and installed on the first pulley and the second pulley, and the two ends of the first lasso are respectively fixed on the first inner arm and the first outer arm, and the two ends of the second lasso are respectively fixed on the second inner arm and the second outer arm.

[0009] As a further solution of the present invention: the motion control system is composed of a drive box, a wheel group and a frame group, and the drive box is sequentially provided with a first drive motor, a second drive motor, a third drive motor and a controller.

[0010] As a further solution of the present invention: the wheel group is composed of a first center wheel, a second center wheel, a first roller group, a second roller group, a third roller group, a fourth roller group and a fifth roller group, the first center wheel is controlled by a first drive motor to swing circumferentially or axially, the second center wheel is controlled by a second drive motor to swing circumferentially or axially, and the limit block connected to the drive box can limit the swing range of the first center wheel and the second center wheel; The fifth roller group is installed on the drive box, and the first roller group, the second roller group, the third roller group and the fourth roller group are installed on the robotic arm. When the first center wheel and the second center wheel rotate, the other roller groups follow the rotation through the action of friction and generate corresponding reaction forces, so that the entire system produces translational or rotational movement.

[0011] As a further solution of the present invention: a method for detecting the grinding quality of the weld surface of an annular outer pipe comprises the following steps: Step 1: Install the annular outer pipe weld surface grinding device on the pipe and fix it through the arm unit; Step 2: Start the binocular stereo vision system to collect images of the pipeline to obtain the target area to be polished; turn on the drive motor and turn it to the axial direction, and drive the polishing device to move to the target area through the motion unit; turn on the drive motor and turn it to the axial direction, and realize circumferential toroidal motion through the rotation of the center wheel group and the roller group; Step 3: Start the third drive motor of the grinding unit, and the grinding unit impacts the oxide layer of the weld through the flexible grinding head to achieve the oxide layer grinding work around the pipeline; Step 4: After grinding is completed, the binocular stereo vision system is started to inspect the grinding quality of the polished pipe. If it does not meet the standard, repeat steps 2 and 3 until the surface grinding of the annular weld in the specified area is completed.

[0012] As a further solution of the present invention: in step 2, the binocular stereo vision system performs image acquisition and calibration on the pipeline through a binocular camera, and preprocesses the two acquired initial images to obtain a first preprocessed image and a second preprocessed image; image segmentation and feature comparison are performed on the first preprocessed image and the second preprocessed image to obtain a first weld image to be polished and a second weld image to be polished; image fusion is performed on the first weld image to be polished and the second weld image to be polished to obtain a target weld image to be polished and a posture; according to the posture relationship and the target weld image to be polished, the coordinates of the non-compliant area and the pipeline diameter are obtained, and the required moving distance and offset angle of the polishing device are adjusted.

[0013] As a further solution of the present invention: in step four, the binocular stereo vision system detects the distance of the outer pipe oxide layer through an infrared ranging sensor, and assists the binocular camera to calculate the coordinates of the unqualified area; the machine vision detection quality uses a deep learning training data set to sample and calibrate the qualified and unqualified grinding quality, and then after taking pictures, the machine learning automatically determines whether the quality is passed, and the oxide layer of the outer pipe weld of the annular surface that does not meet the standards is polished again.

[0014] Beneficial effects of the present invention: 1) The main body of the present invention adopts a semi-open structure connected by hinges, and the pipe to be polished does not need to be adjusted. The machine main body can be installed by changing the angle of the mechanical arm to open or hold it tightly.

[0015] 2) Use pressure sensors and electromagnetic adsorption devices to control the lasso and pulley mechanism to ensure that the contact requirements between the robotic arm and the pipeline are met. Use a binocular stereo vision system to observe the working range of the grinding head, and an infrared ranging sensor to detect the thickness of the weld oxide layer in the target area to ensure the grinding quality and avoid possible errors during the grinding process.

[0016] 3) The multifunctional external pipe grinding system replaces the traditional hand-held grinding. Compared with the traditional method, it can perform comprehensive grinding of the pipe oxide layer, with the advantages of good efficiency, safety and easy operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings.

[0018] Figure 1 It is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 This is a schematic diagram of the structure of the grinding unit of the present invention; Figure 4 This is a schematic diagram of the arm unit structure of the present invention; Figure 5 It is a schematic diagram of the structure of the electromagnetic adsorption device of the present invention; Figure 6 This is a schematic diagram of the structure of the drive box of the present invention; Figure 7 It is a schematic diagram of the mechanical structure of the circular motion process of the present invention; Figure 8 It is a schematic diagram of the mechanical structure of the axial motion process of the present invention; Fig. 9 Schematic diagram of the trajectory of the center of the grinding head of the present invention when the grinding head grinds the pipe once Fig.10 This is a three-dimensional vision principle diagram of the binocular camera of the present invention; Fig.11 The relationship between the grinding head coordinate system and the world coordinate system; Fig.12 This is a schematic diagram of the control target movement principle of the present invention.

[0019] In the figure: 1, binocular stereo vision system; 2, flexible grinding head device; 3, driving box; 4, pressure sensor group; 5, electromagnetic adsorption device; 6, mechanical arm group; 7, wheel group; 8, frame group; 9, first inner arm; 10, first suction cup electromagnet; 11, first inductive pressure sensor; 12, second inner arm; 13, second inductive pressure sensor; 14, second suction cup electromagnet; 15, second lasso; 16, second roller group; 17, second pulley; 18, third inductive pressure sensor; 19, third suction cup electromagnet; 20, third roller group; 21, second outer arm; 22, fourth roller group; 23 , first outer arm; 24, fourth suction cup electromagnet; 25, fourth inductive pressure sensor; 26, first pulley; 27, first roller group; 28, first lasso; 29, first drive motor; 30, second drive motor; 31, third drive motor; 32, controller; 33, first center wheel; 34, second center wheel; 35, fifth roller group; 36, binocular camera; 37, infrared ranging sensor; 2-1, flexible grinding head; 2-2, crank rocker mechanism; 2-3, spring; 2-4, sleeve; 5-1, fixed cover plate; 5-2, armature; 5-3, yoke; 5-4, copper coil; 5-5, sealant. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] See also Figure 1 As shown, the present invention is a surface grinding device for the outer annular pipe weld for cleaning the oxide layer of the outer wall of the superheated steam pipe in a power plant; the device comprises a grinding unit, an arm unit and a motion control system. The grinding unit is composed of a binocular stereo vision system 1 and a flexible grinding head device 2; the arm unit is composed of a pressure sensor group 4, an electromagnetic adsorption device 5 and a mechanical arm group 6; the motion control system is composed of a drive box 3, a wheel group 7 and a frame group 8.

[0022] The binocular stereo vision system 1 includes a binocular camera 36 and an infrared ranging sensor 37; The flexible grinding head device comprises a flexible grinding head 2-1 and a crank-rocker mechanism 2-2. The flexible grinding head 2-1 and the crank-rocker mechanism 2-2 are connected via a sleeve 2-4, and a spring 2-3 runs through the sleeve 2-4.

[0023] The binocular camera 36 is installed on the inner side of the drive box 3, and can monitor the displacement of the flexible grinding head 2-1 and the target grinding area. The infrared ranging sensor 37 and the binocular camera 36 are installed in the same straight line, and can detect the condition of the pipeline area to be polished and the grinding quality, and feed back the signal to the controller 32, and adjust the working progress of the flexible grinding head device 3 by the swing of the crank rocker mechanism 2-2.

[0024] The electromagnetic adsorption device 10 includes an armature 5-2, a yoke 5-3, and a copper coil 5-4. The armature 5-2 runs through the center of the copper coil 5-4. After the yoke 5-3 is added, the armature 5-2 and the yoke 5-3 form a closed magnetic circuit. The fixed cover plate 5-1 and the sealant 5-5 seal the entire device.

[0025] The first inductive pressure sensor 11, the second inductive pressure sensor 13, the third inductive pressure sensor 18 and the fourth inductive pressure sensor 25 in the arm unit are installed beside the electromagnetic adsorption device. The first inductive pressure sensor 11 is provided with a first suction cup electromagnet 10 on one side, the second inductive pressure sensor 13 is provided with a second suction cup electromagnet 14 on one side, the third inductive pressure sensor 18 is provided with a third suction cup electromagnet 19 on one side, and the fourth inductive pressure sensor 25 is provided with a fourth suction cup electromagnet 24 on one side. The pressure change between the electromagnetic adsorption device and the external pipeline can be detected. The movement of the magnetic core caused by the pressure change will change the sensor induced current. The current signal is converted into a usable signal and fed to the controller 32. The mechanical arm angle is adjusted by controlling the magnitude of the electromagnetic adsorption force, so that the arm unit and the external pipeline are opened and closed.

[0026] The mechanical arm group 6 consists of a first inner arm 9, a second inner arm 12, a first outer arm 23, a second outer arm 21, a first lasso 28, a second lasso 15, a first pulley 26 and a second pulley 17; the first inner arm 9 and the second inner arm 12 are connected to the drive box 3 through a hinge, the first inner arm 9 and the first outer arm 23 are connected through a hinge, the second inner arm 12 and the second outer arm 21 are connected through a hinge, the first pulley 26 is installed in a U-shaped groove on the first inner arm 9, the second pulley 17 is installed in a U-shaped groove on the second inner arm 12, the first lasso 28 and the second lasso 15 are distributed and installed on the first pulley 26 and the second pulley 17, and the two ends of the first lasso 28 are respectively fixed on the first inner arm 9 and the first outer arm 23, and the two ends of the second lasso 15 are respectively fixed on the second inner arm 12 and the second outer arm 21.

[0027] The driving box includes a first driving motor 29, a second driving motor 30, a third driving motor 31 and a controller 32, and the wheel is composed of a first center wheel 33, a second center wheel 34, a first roller group 27, a second roller group 16, a third roller group 20, a fourth roller group 22 and a fifth roller group 35. The first center wheel 33 is controlled by the first driving motor 29 to swing circumferentially or axially, and the second center wheel 34 is controlled by the second driving motor 30 to swing circumferentially or axially, and the limit block connected to the box body can limit the swing range of the first center wheel 33 and the second center wheel 34. The fifth roller group 35 is installed on the driving box 3, and the first roller group 27, the second roller group 16, the third roller group 20 and the fourth roller group 22 are installed on the robot arm. When the first center wheel 33 and the second center wheel 34 rotate, the other roller groups follow the rotation through the action of friction and generate corresponding reaction forces, so that the entire system produces translational or rotational movement.

[0028] The control method of the device for grinding the surface of the pipe weld outside the annular surface comprises the following steps; Step 1: Install the annular outer pipe weld surface grinding device on the pipe and fix it through the arm unit; Step 2: Start the binocular stereo vision system 1, collect images of the pipeline, and obtain the target area to be polished; turn on the drive motor and turn it to the axial direction, and drive the polishing device to move to the target area through the motion unit; turn on the drive motor and turn it to the axial direction, and realize circumferential toroidal motion through the rotation of the center wheel group and the roller group.

[0029] Step 3: Start the third drive motor 31 of the grinding unit. The grinding unit impacts the oxide layer of the weld through the flexible grinding head 3 to achieve the oxide layer grinding work around the entire circumference of the pipeline.

[0030] Step 4: After the grinding is completed, the binocular stereo vision system 1 is started to inspect the grinding quality of the polished pipe. If it does not meet the standard, steps 2 and 3 are repeated until the surface grinding of the annular weld in the specified area is completed.

[0031] The binocular stereo vision system 1 performs image acquisition and calibration on the pipeline through the binocular camera 36, ​​and pre-processes the two acquired initial images to obtain a first pre-processed image and a second pre-processed image; performs image segmentation and feature comparison on the first pre-processed image and the second pre-processed image distribution to obtain a first weld image to be polished and a second weld image to be polished; performs image fusion on the first weld image to be polished and the second weld image to be polished to obtain a target weld image to be polished and a posture; according to the posture relationship and the target weld image to be polished, the coordinates of the non-compliant area and the pipeline diameter are obtained, and the required moving distance and offset angle of the polishing device are adjusted.

[0032] The binocular stereo vision system 1 detects the distance of the outer pipe oxide layer through the infrared distance measuring sensor 37, and assists the binocular camera to calculate the coordinates of the unqualified area. The machine vision inspection quality uses the deep learning training data set to sample and calibrate the qualified and unqualified grinding quality, and then after taking pictures, the machine learning automatically determines whether the quality is passed, and the unqualified ring surface outer pipe weld oxide layer is polished again.

[0033] The present application is further described below in conjunction with the accompanying drawings: In order to meet the needs of grinding pipes of different sizes, the present invention adopts a semi-open structure, and in order to ensure the stability of the grinding device, a suction cup type electromagnet is used to control the mechanical arm.

[0034] like Figure 2 As shown, the mechanical part of the present invention is mainly composed of a grinding unit and a motion control system to realize the operation and movement of the pipeline grinding device. The arm unit ensures the stability of the device. The drive box 3 controls the coordinated operation of various mechanisms. In addition, there is a binocular stereo vision system 1 to assist the grinding device in determining the target area, judge the oxidation condition of the pipeline, effectively mark and warn of major damage, and visualize and controllable the grinding process.

[0035] During the working process, the grinding device mainly needs to ensure its circumferential and axial stability to complete the grinding task well. The stability of the present invention is mainly achieved by adjusting the relative position of the entire device in the axial direction in real time according to the feedback of the position and inductive sensor by the suction cup electromagnet to meet the working requirements.

[0036] like Figure 3 As shown, the flexible grinding head device includes a flexible grinding head 2-1 and a crank rocker mechanism 2-2. The flexible grinding head 2-1 and the crank rocker mechanism 2-2 are connected by a sleeve 2-4, and a spring 2-3 runs through the sleeve 2-4. During the grinding process, the flexible grinding head 2-1 is mainly used for grinding, the spring 2-3 controls the thickness of the grinding layer, and the binocular camera 36 monitors the center position of the grinding head to make the process controllable. Fig. 9 As shown in the schematic diagram of the center trajectory of the grinding head, the crank rocker mechanism 2-2 regulates the moving range of the grinding head, and the binocular stereo vision system 1 observes the grinding situation to visualize the grinding process.

[0037] like Figure 4 and Figure 5 The arm unit shown uses adsorption technology, and through electromagnetic adsorption, the device can work on walls with different inclination angles. In order to ensure the basic static stable adsorption of the device and to safely cling to the wall when walking, this design chooses a suction cup electromagnet device, which is similar to a suction cup in appearance. It can adsorb metal pipes by generating electromagnetic force by energizing the coil. When the power is disconnected, the current in the coil disappears, and the magnetic field disappears, and the suction cup will detach from the metal surface, which has the advantages of energy saving, environmental protection, and strong suction.

[0038] like Figure 6 Figure 7 Figure 8 As shown, the axial and circumferential motions are driven by the third drive motor 31, and the electromagnetic fork controls the sliding gear to control the meshing of the stepper motor with the adjustment gear and the center wheel, thereby achieving separate control under different conditions and realizing that the two functions are powered by the same stepper motor without interfering with each other.

[0039] like Fig.10 As shown in the figure, binocular stereo vision technology uses two cameras of the same model to simulate the human eye to collect image information of the same target at different positions at the same time, and calculates the position deviation of all corresponding pixels in the two images to obtain the three-dimensional spatial information of the target object. The internal parameters of the two cameras in the figure are the same, the world coordinate system coincides with the left camera coordinate system, (x0, y0) is the origin of the coordinate system, the focal length is f, the base moment B is the moment between the optical centers of the two cameras, the optical axes of the two cameras are parallel and the intersection points with the image plane are OL and OR, and the left and right image planes coincide. When starting and ending the work, the grinding head is reset, and the projection of the target grinding point P (x, y, z) on the image planes of the two cameras is PL (xl, yl) and PR (xr, yr). The y coordinates in the left and right pictures are the same, that is, yl=yr. From the trigonometric relationship, the three-dimensional coordinates of the target point P in the world coordinate system can be obtained as follows: It can be seen from the formula that there is parallax between points Pl and Pr only in the horizontal axis: like Fig.11 As shown in the figure, if you want to truly achieve the purpose of external pipe grinding, you need to know the position of the target to be ground in the grinding head coordinate system. At this time, you need to convert the coordinates in the world coordinate system to the grinding head coordinate system, and obtain it through measurement. , the rotation matrix is , it is known that the point P in the world coordinate system is (x, y, z), and the position of this point in the grinding head coordinate system is P'(x1, y1, z1), the expression is as follows: like Fig.12 As shown, from the perspective transformation geometric relationship, it can be known that the mathematical relationship between the grinding head center Q (xc, yc, zc), the target grinding point P' (x1, y1, z1) and the external pipe is as follows: , From this we can know Where θ is the offset angle between the center of the grinding head and the target grinding point; R is the radius of the grinding pipe; and L is the distance the grinding device travels to the target area.

[0040] When the device starts running, the binocular stereo vision system feeds back image signals to determine the target grinding point P. The controller controls the device to move θ degrees to the target area for work. The pipeline radius R and the working motion path L of the pipeline grinding device can be fed back in time according to the feedback signal, which is convenient for outputting work reports.

[0041] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A device for grinding the weld surface of an annular pipe. It is characterized in that It includes a motion control system for controlling the motion of the grinding unit and the arm unit; A grinding unit, used for identifying the weld on the pipeline surface and grinding the oxide layer around the entire pipeline, wherein the grinding unit is arranged on the motion control system; The polishing unit comprises a binocular stereoscopic vision system (1) for collecting images of the pipeline to obtain a target area to be polished; and also comprises a flexible polishing head device (2) for polishing the pipeline surface at multiple angles; The arm unit is used for fixing the pipeline, and the arm unit is arranged on the motion control system.

2. A device for grinding the weld surface of an annular outer pipe according to claim 1, It is characterized in that The binocular stereo vision system comprises an infrared distance measuring sensor (37) and a binocular camera (36); the flexible grinding head device comprises a flexible grinding head (2-1), a crank rocker mechanism (2-2), and the flexible grinding head (2-1) and the crank rocker mechanism (2-2) are connected via a sleeve (2-4), and a spring (2-3) runs through the sleeve (2-4).

3. A device for grinding the weld surface of an annular outer pipe according to claim 2, It is characterized in that The binocular camera (36) is installed on the inner side of the drive box and is used to monitor the displacement between the flexible grinding head (2-1) and the target grinding area. The binocular camera (36) and the infrared distance measuring sensor (37) are installed on the same straight line and are used to detect the condition of the area to be polished of the pipeline and the grinding quality, and to feed back the signal to the controller (32). The working process of the flexible grinding head device (3) is adjusted by the swing of the crank rocker mechanism (2-2).

4. The device for grinding the weld surface of an annular outer pipe according to claim 1, It is characterized in that The arm unit is composed of a pressure sensor group (4), an electromagnetic adsorption device (5) and a mechanical arm group (6); The electromagnetic adsorption device (5) comprises an armature (5-2), a yoke (5-3), and a copper coil (5-4); the armature (5-2) passes through the center of the copper coil (5-4); after the yoke (5-3) is added, the armature (5-2) and the yoke (5-3) form a closed magnetic circuit; the fixed cover plate (5-1) and the sealant (5-5) seal the entire device; A first inductive pressure sensor (11), a second inductive pressure sensor (12), a third inductive pressure sensor (18) and a fourth inductive pressure sensor (25) are installed on the side of the electromagnetic adsorption device (5) for detecting the pressure change between the electromagnetic adsorption device (5) and the external pipeline. The movement of the magnetic core caused by the pressure change will change the sensor induced current, and the current signal is converted into a usable signal and fed to the controller (32). By controlling the magnitude of the electromagnetic adsorption force, the mechanical arm angle is adjusted, so that the arm unit and the external pipeline are opened and closed.

5. A device for grinding the weld surface of an annular outer pipe according to claim 4, It is characterized in that The mechanical arm group (6) is composed of a first inner arm (9), a second inner arm (12), a first outer arm (23), a second outer arm (21), a first lasso (28), a second lasso (15), a first pulley (26) and a second pulley (17); the first inner arm (9) and the second inner arm (12) are connected to the drive box (3) via a hinge, the first inner arm (9) and the first outer arm (23) are connected via a hinge, the second inner arm (12) and the second outer arm (21) are connected via a hinge, and the The first pulley (26) is installed in a U-shaped groove on the first inner arm (9), the second pulley (17) is installed in a U-shaped groove on the second inner arm (12), the first lasso (28) and the second lasso (15) are installed on the first pulley (26) and the second pulley (17), and the two ends of the first lasso (28) are respectively fixed on the first inner arm (9) and the first outer arm (23), and the two ends of the second lasso (15) are respectively fixed on the second inner arm (12) and the second outer arm (21).

6. The device for grinding the weld surface of an annular outer pipe according to claim 1, It is characterized in that The motion control system is composed of a drive box (3), a wheel group (7) and a frame group (8), and a first drive motor (29), a second drive motor (30), a third drive motor (31) and a controller (32) are sequentially arranged in the drive box (3).

7. A device for grinding the weld surface of an annular outer pipe according to claim 6, It is characterized in that The wheel group (7) is composed of a first center wheel (33), a second center wheel (34), a first roller group (27), a second roller group (16), a third roller group (20), a fourth roller group (22) and a fifth roller group (35); the first center wheel (33) is controlled by a first drive motor (29) to swing circumferentially or axially; the second center wheel (34) is controlled by a second drive motor (30) to swing circumferentially or axially; and a limit block connected to the drive box can limit the swing range of the first center wheel (33) and the second center wheel (34); The fifth roller group (35) is mounted on the drive box (3), and the first roller group (27), the second roller group (16), the third roller group (20) and the fourth roller group (22) are mounted on the robot arm. When the first center wheel (33) and the second center wheel (34) rotate, the other roller groups rotate along with the friction force and generate corresponding reaction forces, so that the entire system generates translational or rotational movement.

8. A method for testing the grinding quality of the weld surface of an annular pipe. It is characterized in that The device for grinding the outer annular pipe weld surface according to any one of claims 1 to 7 comprises the following steps: Step 1: Install the annular outer pipe weld surface grinding device on the pipe and fix it through the arm unit; Step 2: Start the binocular stereo vision system (1) to collect images of the pipeline and obtain the target area to be polished; turn on the drive motor and rotate it to the axial direction, and drive the polishing device to move to the target area via the motion unit; turn on the drive motor and rotate it to the axial direction, and realize circumferential toroidal motion via the rotation of the center wheel group and the roller group; Step 3: starting the third drive motor (31) of the grinding unit, so that the grinding unit impacts the oxide layer of the weld through the flexible grinding head (3), thereby grinding the oxide layer around the entire circumference of the pipeline; Step 4: After the grinding is completed, the binocular stereo vision system (1) is started to inspect the grinding quality of the polished pipe. If it does not meet the standard, steps 2 and 3 are repeated until the surface grinding of the annular weld in the specified area is completed.

9. A method for detecting the grinding quality of the weld surface of an annular outer pipe according to claim 8, It is characterized in that In step 2, the binocular stereo vision system (1) performs image acquisition and calibration on the pipeline through the binocular camera (36), and pre-processes the two acquired initial images to obtain a first pre-processed image and a second pre-processed image; performs image segmentation and feature comparison on the first pre-processed image and the second pre-processed image to obtain a first weld image to be polished and a second weld image to be polished; performs image fusion on the first weld image to be polished and the second weld image to be polished to obtain a target weld image to be polished and a posture; obtains the coordinates of the non-compliant area and the pipeline diameter based on the posture relationship and the target weld image to be polished, and adjusts the required moving distance and offset angle of the polishing device.

10. A method for detecting the grinding quality of the weld surface of an annular outer pipe according to claim 8, It is characterized in that In step 4, the binocular stereo vision system (1) detects the distance of the outer pipe oxide layer through the infrared distance measuring sensor (37), and assists the binocular camera to calculate the coordinates of the unqualified area; the machine vision detection quality is sampled and calibrated by the deep learning training data set for qualified and unqualified grinding quality, and then the machine learning automatically determines whether the quality is passed after taking a picture, and the outer pipe weld oxide layer of the annular surface that does not meet the standard is polished again.

Images