A detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap

Abstract

A detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap relates to the field of mechanical automation engineering. It includes a vehicle body, a drive system, a calibration and video detection system, a magnetic flux leakage and displacement detection system, a magnetization and adsorption system, a transmission cable, a ground station control box and an automatic tracking pan-tilt head that are interconnected; the vehicle body includes a multifunctional lifting handle, a shell, a control box, a rear handle, and a body bracket; the multifunctional lifting handle can not only realize the lifting function through the lifting eye screw, but also change the position through the quick plug-in pin to realize different forms, from the lifting bracket to the front handle, and move the robot together with the rear handle; the skeleton is also equipped with a control box for controlling the drive system and the calibration and video detection system; the robot body bracket is made of carbon fiber. The present invention provides a detection robot with high sensitivity and high precision based on a rag-type magnetic sensor and a fixed magnetic yoke.

Description

Technical Field

[0001] The invention relates to the field of mechanical automation engineering, and in particular to a detection robot based on a rag-type magnetic sensitive sensor and a fixed magnetic yoke with a gap. Background Art

[0002] Large pressure-bearing equipment such as supercritical power station boilers and spherical tanks usually work in harsh environments such as high pressure and corrosion, and their safety and reliability are extremely important. Due to the pressure and medium corrosion on the inner wall of the pressure-bearing equipment, defects such as pits, cracks, and holes may occur on the tank wall. These defects will not only cause medium leakage, but may even cause explosions and fires, so regular inspections are necessary. At present, the surface inspection of pressure-bearing equipment is mainly based on internal surface inspection, and most of it is done manually. If the height or diameter of the tank is greater than the height of a human body, scaffolding or other climbing devices must be built inside the tank, which has the disadvantages of high labor intensity for operators, dangerous operations, and low efficiency.

[0003] In recent years, due to the increasing demand for special robots in the high-end equipment manufacturing industry, the research on automatic inspection robots has attracted much attention. At present, researchers at home and abroad have developed various types of automatic inspection robots to meet the different needs of the high-end equipment manufacturing industry.

[0004] Large-scale pressure-bearing equipment automatic inspection robots usually use wall-climbing robots with wheeled omnidirectional mobile mechanisms. The omnidirectional mobile mechanism is generally composed of 3 to 4 directional sliding wheels. The wheeled omnidirectional mobile mechanism not only has the rapidity, flexibility and controllability of the wheeled mobile mechanism, but also can move in any direction on the plane or rotate at any angle on the spot while keeping the body's orientation unchanged.

[0005] In terms of automation of non-destructive testing, Zhejiang University of Technology has designed a magnetic particle inspection robot, which consists of two parts: a wall-mounted mobile carrier and a detection mechanism. The wall-mounted mobile carrier consists of a motion mechanism, an adsorption mechanism, a body frame, and a control cabinet, and can independently crawl on the wall. Functional devices such as magnetization, magnetic spraying, and defect marking in the detection mechanism are all installed on the mobile carrier. Its design is mainly to simulate the process of arm operating the detection equipment during manual inspection. The Shenyang Institute of Automation of the Chinese Academy of Sciences has designed a wall-climbing inspection robot, including a magnetic particle flaw detection and thickness detection system, a video detection system, and a chassis system. The chassis system includes a vehicle bottom flatbed, a driven wheel assembly, a drive motor, and a drive wheel part. The use of a wheeled mobile platform can implement detection and inspection work on complex working interfaces such as curved surfaces and arcs. However, most of the wall-climbing magnetic particle automatic inspection robots currently developed are wall-climbing robots with external inspection equipment, which have the following disadvantages: First, the magnetic particle inspection robots currently developed mainly use cross-magnetic yoke magnetic particle flaw detectors. For pressure-bearing equipment, due to its structural characteristics, when the surface of the workpiece to be inspected is a curved surface or due to the influence of the weld misalignment and edge angles, its four magnetic poles cannot contact the workpiece surface well, and one magnetic pole will be suspended in the air (on the spherical surface), or four magnetic poles will contact the workpiece surface in a line contact manner (on the cylindrical surface), thus generating a large magnetic resistance between a pair of magnetic poles, thereby reducing the detection sensitivity in certain directions; although the NB / T 47013.4-2015 standard stipulates that the maximum gap should not exceed 0.5mm, it is difficult to guarantee the maximum gap of 0.5mm in actual detection. Second, when using a rotating magnetic field magnetic particle flaw detector for inspection, the magnetic suspension is sprayed while moving the magnetization, so it is even more important to avoid the defective magnetic traces that have been formed due to the flow damage of the magnetic suspension. This requires that the spraying of the magnetic suspension should be well coordinated with the detection speed of the cross magnetic yoke while ensuring that the effective magnetizing field is completely wetted, so that the tiny defective magnetic traces can be revealed. The requirements for this coordination are: within the range of the moving effective magnetizing field, there must be magnetic powder that can be attracted by the defect leakage magnetic field, and at the same time, the flow of the magnetic suspension is not allowed to destroy the already formed defective magnetic traces. If the coordination is not good, even if defective magnetic traces are formed, they will be destroyed. Therefore, the most difficult part of using the cross magnetic yoke is the spraying of the magnetic suspension. The spraying technique needs to be adjusted according to the detection speed of the cross magnetic yoke, the spatial position of the inspected part, etc., but in actual detection, the magnetic suspension spraying technique is difficult to automatically identify and adjust.Third, in order to realize the spraying function of the magnetic suspension, the magnetic suspension is usually sprayed continuously and stably through the conveying pipe. At present, the magnetic powder inspection robot is usually a wall-climbing robot with a cross yoke for inspection. In order to reduce the dead weight of the cross yoke, the spacing of the cross yoke is small. Generally speaking, when a cross yoke with a span width of 100mm is made of better cold-rolled silicon steel sheets, its weight is about 7 kilograms, but the smaller span width leads to a shorter magnetization time, because the cross yoke is magnetized during walking, and the time to walk this distance is also short when the span width is small. Fourth, the cross yoke produces an alternating changing magnetic field with low adsorption force. In order to enhance the wall climbing ability, a permanent magnet magnetic wheel or magnet should be added. If the magnetic wheel or magnet is close to the cross yoke, these magnetic wheels or magnets will more or less interfere with the magnetic field formed by the cross yoke. Fifth, the magnetic particle inspection robots currently developed are mainly used for surface defect inspection, and their detection capabilities for near-surface defects are relatively poor. They are also unable to inspect the shape and size of welds, such as weld misalignment, excessive excess height, and excessive angles. Sixth, in order to achieve weld tracking during the inspection process, the magnetic particle inspection robots currently developed have added a laser tracking system, which increases weight and cost. Seventh, the post-cleaning of the remaining magnetic powder after the magnetic particle inspection is completed is usually difficult to achieve, which affects the subsequent production environment (especially in situations where the medium purity requirements are high). Summary of the invention

[0006] The object of the present invention is to overcome the deficiencies of the above-mentioned background technology and to provide a detection robot based on a rag-type magnetic sensitive sensor and a fixed magnetic yoke with a gap.

[0007] The technical solution provided by the present invention is: a detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap, including a vehicle body, a drive system, a calibration and video detection system, a magnetic flux leakage and displacement detection system, a magnetization and adsorption system, a transmission cable, a ground station control box and an automatic tracking pan-tilt. The vehicle body includes a multifunctional lifting handle, a shell, a control box, a rear handle, and a body bracket; the multifunctional lifting handle can not only realize the lifting function through the lifting eye screw, but also change the position through the quick plug-in pin to realize different forms, and change from a lifting bracket to a front handle, and move the robot together with the rear handle; the control box for controlling the driving system and the calibration and video detection system is also installed on the skeleton, and the control box adopts aviation aluminum material to ensure the strength of the extreme weight reduction design, and at the same time, the structure made to adapt to the high temperature generated by the operation of the electronic control components has a good heat dissipation effect, ensuring the normal operation of the entire equipment; the robot body bracket is made of carbon fiber material, the density is lower than that of aviation aluminum, but the strength is much higher than that of aviation aluminum material, which effectively reduces the weight of the robot body.

[0008] The power conversion system is electrically connected to a control box installed on the frame, and the wireless remote controller is also connected to a wireless transceiver component in the control box through a wireless signal to achieve wireless control.

[0009] Preferably, the drive system includes a motor, a reducer, a universal wheel, and a driving rubber wheel. The drive mainly adopts two motors and two reducers, differential drive, and flexible control. Dual-wheel differential drive, forward, backward, 360° rotation, equipped with a lightweight handheld remote control unit. The dual-motor differential drive solution can ensure that the robot can move and turn freely when adsorbed on the surface of large pressure-bearing equipment. The robot driving rubber wheel material is made of aviation aluminum and high-grade rubber coating. The surface of the rubber-coated wheel is grooved to increase the friction and adhesion of the wheel, which is non-slip, high temperature and corrosion-resistant; the robot's universal wheel adopts a high-strength double-row plastic wheel set with strong anti-slip ability; the universal wheel is flexible in steering and can move freely on non-planar work surfaces.

[0010] Preferably, the calibration and video detection system includes a front camera system, a front lighting, a laser aligner, etc., which are installed in front of the wall-climbing walking mechanism. The calibration and video detection system emits two laser beams on both sides of the weld to facilitate alignment of the weld, so that the robot can walk along the weld and observe the situation in front of the robot.

[0011] Preferably, the magnetic flux leakage and displacement detection system adopts a rag-type magnetic sensor, which includes a magnetic probe, an elastic rag, a spring, a displacement detection and navigation system. Multiple groups of magnetic probes are installed on the elastic rag, and the rag automatically adapts to the arc of the weld surface of the spherical tank by relying on the spring force and the elasticity of the rag itself, and fits closely with it; so that the magnetic probe on the elastic rag can accurately align with the weld and be as close to the weld surface as possible, so that the magnetic probe can reliably detect the leakage magnetic field generated by surface and near-surface defects. Since the magnetic probe is small in size, the spatial detection range is limited. In order to expand the detection range and improve the detection accuracy, a detection method of 15 sensors in 4 rows forming a one-dimensional array is adopted. The spacing between adjacent magnetic probes in the same array is 2mm, and the adjacent array sensors are staggered by 0.5mm, so as to form a scanning detection structure without a detection blind spot, and the close contact between the probe and the detection surface can be achieved. In addition, the rag-type magnetic sensor is also equipped with a displacement sensor, or to check the shape and size of the weld, and check the defects of the weld such as misalignment, excessive excess height, and excessive angle. The signal of the displacement sensor is coupled with the robot driving system, and the signal of the displacement sensor can be used to enable the robot to track and walk along the weld, replacing the currently widely used laser tracking system, reducing weight and cost.

[0012] Preferably, the magnetization and adsorption system adopts a fixed yoke with a gap to achieve the dual functions of magnetization and adsorption. In order to detect defects in different directions, a vertical weld magnetization fixed yoke and a parallel weld magnetization fixed yoke are provided. The vertical weld magnetization fixed yoke is installed between a pair of driving rubber wheels, and the parallel weld magnetization fixed yoke is installed between a pair of universal wheels; the vertical weld magnetization fixed yoke includes a pair of first NS antiparallel magnets, a first intermediate magnetic circuit strengthening magnet, a ferrite soft magnetic matching magnetic bridge, a second mounting plate, a first walking bearing, and a suspension spring. The vertical weld magnetization fixed yoke has a certain gap with the wall surface to achieve walking and climbing over obstacles, and to ensure sufficient adsorption force. A pair of first NS antiparallel magnets, a first intermediate magnetic circuit strengthening magnet, and a ferrite soft magnetic matching magnetic bridge form a complete first magnetic circuit with the wall surface through an air gap. The ferrite soft magnetic matching magnetic bridge can conduct magnetism on the one hand, and on the other hand, threaded holes are machined on the magnetic bridge. The first screw can play the role of fixing the magnet and installing the second mounting plates on both sides. The first screw is made of ferromagnetic material so that it basically does not affect the magnetic The second mounting plate plays the role of fixing the protective magnet. The outer side of the bottom of the mounting plate protecting the first NS antiparallel magnet has an arc surface curvature, and the first walking bearing is installed to improve the obstacle performance and walking performance. In addition, the second mounting plate is fixedly connected to the first mounting plate of the rag-type magnetic sensor by bolts, so that the magnetic sensitive probe is in the middle of the magnetic yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface; there is a suspension spring above the fixed magnetic yoke, and the spring stiffness is designed to make the walking wheel just touch the wall when walking on the back, and there is a certain interaction force between the walking wheel and the wall at other positions, so that the gap between the fixed magnetic yoke and the wall is basically the same, so that it has a more consistent detection sensitivity; the parallel weld magnetization fixed magnetic yoke, in order to avoid the influence of the weld excess height, adopts a symmetrical cross magnetic yoke for magnetization, including two pairs of second NS antiparallel magnets, two pairs of second intermediate magnetic circuit strengthening magnets, ferrite soft magnetic matching cross magnetic bridge, third mounting plate, second walking bearing, suspension spring; the fixed magnetic yoke has a certain gap with the wall to achieve walking and climbing over obstacles, and can ensure sufficient adsorption force, The second NS antiparallel magnet, the second intermediate magnetic circuit strengthening magnet, and the ferrite soft magnetic matching cross magnetic bridge form a complete second magnetic circuit with the wall through the air gap; on the one hand, the ferrite soft magnetic matching cross magnetic bridge can conduct magnetism, and the middle part is shared by the cross magnetic circuit. On the other hand, threaded holes are processed on the magnetic bridge, and the magnets and the third mounting plate can be fixed by screws. The screws are made of ferromagnetic materials so that they basically do not affect the passage of the magnetic circuit. In addition, threaded holes are processed in the middle part of the ferrite soft magnetic matching cross magnetic bridge, which is fixedly connected to the first mounting plate of the rag-type magnetic sensor through bolts, so that the magnetic sensitive probe is in the middle of the magnetic yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface; on the one hand, the first mounting plate plays the role of fixing the protective magnet, and the outer side of the bottom of the mounting plate has a circular arc curvature, and the first walking bearing is installed to improve the obstacle-passing performance and walking performance;There is a certain gap between the fixed yoke and the wall to enable walking and climbing over obstacles while ensuring sufficient adsorption force. ;

[0013] Preferably, the first mounting plate on the rag-type magnetic sensor is fixedly connected to the second mounting plate on the vertical weld magnetization fixed yoke. The second mounting plate is provided with a guide column, the body bracket connecting plate is provided with a sleeve, a spring is installed between the sleeve and the guide column, and the body bracket connecting plate is fixedly connected to the body bracket through screws.

[0014] Preferably, the fourth mounting plate on the rear wipe type magnetic sensor is fixedly connected to the third mounting plate on the parallel weld magnetization fixed yoke; the third mounting plate is provided with a guide column, and the main body bracket connecting plate is provided with a sleeve, a spring is installed between the sleeve and the guide column, and the main body bracket connecting plate is fixedly connected to the main body bracket by screws.

[0015] The detection robot ground station control box is used in conjunction with the robot to realize the functions of robot motion control, detection signal, and high-definition camera image return. All operations on the remote control can be completed through the ground station control box. The ground station control box consists of a display, a control panel, a power switch, an emergency stop switch, cables, a wire rack (built-in encoder), a power supply and other components.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The robot adopts the leakage magnetic field detection technology of magnetic sensitive elements, with the advantages of simple probe structure, no need for coupling agent, high detection sensitivity, fast detection speed, low missed detection rate and high detection accuracy.

[0018] 2. The magnetic particle inspection robot's magnetic flux leakage and displacement detection system adopts a rag-type magnetic sensor. Multiple sets of magnetic probes are installed on an elastic rag. Relying on the spring force and the elasticity of the rag itself, the rag automatically adapts to the surface curvature of the spherical tank weld and fits closely with it, so that the magnetic probe on the elastic rag can be accurately aligned with the weld and as close to the weld surface as possible, so that the magnetic probe can reliably detect the leakage magnetic field generated by surface and near-surface defects.

[0019] 3. The rag-type magnetic sensor also has a displacement sensor, which can be used to check the shape and size of the weld, and check for defects such as misalignment, excessive excess height, and excessive angles. The signal of the displacement sensor is coupled with the robot drive system, and the signal of the displacement sensor can be used to enable the robot to track and walk along the weld, replacing the currently widely used laser tracking system, reducing weight and cost.

[0020] 4. The magnetization and adsorption system uses a fixed yoke with a gap to achieve the dual functions of magnetization and adsorption. There is a certain gap between the fixed yoke and the wall to achieve walking and climbing over obstacles, and to ensure sufficient adsorption force. For magnetization perpendicular to the weld, a pair of parallel yokes are used, and the magnetic sensitive probe is placed in the middle of the yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface. For magnetization parallel to the weld, in order to avoid the influence of the weld residual height, a symmetrical cross yoke is used for magnetization, and the magnetic circuit is designed to ensure that the magnetic field in the middle area of ​​the cross yoke is parallel to the weld. The magnetic sensitive probe is placed in the middle of the cross yoke to obtain the leakage magnetic field information of the transverse defects on the weld surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the overall structure of the detection robot.

[0022] Figure 2 for Figure 1 Schematic diagram of the top view structure.

[0023] Figure 3 This is a schematic diagram of the structure of a rag-type magnetic sensor.

[0024] Figure 4 for Figure 3 Schematic diagram of the top view structure.

[0025] Figure 5 Schematic diagram of the fixed yoke for vertical weld magnetization.

[0026] Figure 6 for Figure 5 Schematic diagram of the top view structure.

[0027] Figure 7 Schematic diagram of the magnetic circuit of the vertical weld magnetized fixed yoke.

[0028] Figure 8 Schematic diagram of the magnetized fixed yoke parallel to the weld.

[0029] Fig. 9 for Figure 8 Schematic diagram of the top view structure.

[0030] Fig.10 Schematic diagram of the magnetic circuit of the parallel weld magnetized fixed yoke.

[0031] Fig.11 This is a schematic diagram of the connection between the rag-type magnetic sensor and the vertical weld magnetization fixed yoke.

[0032] Fig.12 This is a schematic diagram of the structure of a rear-rag type magnetic sensor.

[0033] Fig.13 It is a schematic diagram of the connection between the rear rag type magnetic sensor and the parallel weld magnetization fixed yoke.

[0034] Fig.14 for Fig.13 Schematic diagram of the top view structure.

[0035] Among them: 1. Vehicle body; 2. Drive system; 3. Calibration and video detection system; 4. Leakage magnetic field and displacement detection system; 5. Magnetization and adsorption system; 6. Transmission cable; 7. Ground station control box; 8. Automatic tracking pan-tilt head; 9. Multi-function lifting handle; 10. Shell; 11. Control box; 12. Rear handle; 13. Body bracket; 14. Motor; 15. Reducer; 16. Universal wheel; 17. Driving rubber wheel; 18. Front camera system; 19. Front lighting; 20. Laser alignment device; 21. Array magnetic sensitive probe; 22. Elastic rag; 23. Spring; 24. Displacement sensor; 25. Circuit integrated board; 26. First mounting board; 27. Integrated cable; 28. Signal Processing system; 29. ​​Vertical weld magnetizing fixed yoke; 30. Parallel weld magnetizing fixed yoke; 31. First NS antiparallel magnet; 32. First intermediate magnetic circuit reinforcing magnet; 33. Ferrite soft magnetic matching magnetic bridge; 34. Second mounting plate; 35. First traveling bearing; 36. Suspension spring; 37. First magnetic circuit; 38. Second NS antiparallel magnet; 39. Second intermediate magnetic circuit reinforcing magnet; 40. Ferrite soft magnetic matching cross magnetic bridge; 41. Third mounting plate; 42. Second traveling bearing; 44. Second magnetic circuit; 45. Wall; 48. First screw; 49. Sleeve; 50. Main bracket connecting plate; 51. Guide column; 52. Second screw; 53. Fourth mounting plate. DETAILED DESCRIPTION

[0036] The present invention will be further described below with reference to the accompanying drawings by way of embodiments.

[0037] The technical solution provided by the present invention is: Figures 1 to 14 As shown, a detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap includes a vehicle body 1, a drive system 2, a calibration and video detection system 3, a leakage magnetic field and displacement detection system 4, a magnetization and adsorption system 5, a transmission cable 6, a ground station control box 7 and an automatic tracking pan-tilt head 8 which are interconnected.

[0038] like Figure 1As shown, the vehicle body 1 includes a multifunctional lifting handle 9, a shell 10, a control box 11, a rear handle 12 and a body bracket 13. The multifunctional lifting handle can realize the lifting function through the lifting eye screws, and can also realize different forms by changing the position of the quick plug-in pin, changing from a lifting bracket to a front handle, and moving the robot together with the rear handle. A control box 11 for controlling the front drive wheel assembly and the video detection system is also installed on the skeleton. The control box 11 is designed to reduce weight to the maximum extent under the premise of ensuring strength using aviation aluminum materials. At the same time, the structure made to adapt to the high temperature generated by the operation of the electronic control components has a good heat dissipation effect, ensuring the normal operation of the entire equipment; the robot body bracket 13 is made of carbon fiber material, which has a lower density than aviation aluminum, but a much higher strength than aviation aluminum materials, which effectively reduces the weight of the robot body.

[0039] like Figure 2 As shown, the drive system 2 includes a motor 14, a reducer 15, a universal wheel 16 and a driving rubber wheel 17. The drive mainly adopts two motors and two reducers, differential drive, and flexible control. Dual-wheel differential drive, forward, backward, 360° rotation, equipped with a lightweight handheld remote control unit. The dual-motor differential drive solution can ensure that the robot can move and turn freely when adsorbed on the surface of large pressure-bearing equipment. The robot driving rubber wheel 17 is made of aviation aluminum and high-grade rubber coating. The surface of the rubber-coated wheel is grooved to increase the friction and adhesion of the wheel, which is non-slip, high temperature and corrosion-resistant; the robot's universal wheel 16 uses a high-strength double-row plastic wheel set with strong anti-slip ability; the universal wheel is flexible in steering and can move freely on non-planar work surfaces.

[0040] like Figure 1As shown, the calibration and video detection system 3 is mainly used for macroscopic inspection of the weld and observation of the weld alignment while walking, including a front camera system 18, a front lighting 19 and a laser aligner 20, which are installed in front of the wall-climbing walking mechanism, and emit two laser beams on both sides of the weld to facilitate alignment of the weld, so that the robot can walk along the weld and observe the situation in front of the robot. The calibration and video detection system consists of two front and rear wide-angle cameras installed on the robot body, an independent camera unit and matching image processing software. The camera has the functions of display, storage and nearby reading. Through the monitoring system, the image information around the robot in the detection environment and the surface condition of the weld directly in front of the robot can be effectively obtained, and the weld can be macroscopically inspected. At the same time, it can assist the operator to effectively identify the surrounding situation and prevent accidents. The camera has its own LED light source, which can meet the needs of camera shooting. The robot uses a visible laser beam to assist in guiding. The laser auxiliary mechanism adopts a laser level to project a laser straight line in front of the robot that is consistent with the forward direction of the robot body. When the straight line coincides with the weld, it indicates that the robot's walking direction is not deviated and can continue to work. When the laser line deviates from the weld, it indicates that the robot's walking direction begins to deviate, and the robot's direction must be adjusted until the laser line coincides with or is parallel to the weld.

[0041] like Figure 3 , Figure 4As shown, the magnetic flux leakage and displacement detection system 4 adopts a rag-type magnetic sensor, which includes an array magnetic probe 21, an elastic rag 22, a spring 23, a displacement sensor 24, a circuit integrated board 25, a first mounting board 26, an integrated cable 27 and a signal processing system 28. Multiple groups of array magnetic probes 21 are installed on the elastic rag 22, and the probe surface is retracted 0.1 mm inward from the elastic rag. In this way, on the one hand, the probe surface does not directly contact the device when the robot moves, causing wear of the device. On the other hand, the rag automatically adapts to the arc of the weld surface of the spherical tank by relying on the spring force and the elasticity of the rag itself, and fits closely with it, so that the magnetic probe 21 on the elastic rag 22 can accurately align with the weld and be as close to the weld surface as possible, so that the magnetic probe 21 can reliably detect the leakage magnetic field generated by surface and near-surface defects. Since the magnetic probe 21 is small in size and has a limited spatial detection range, in order to expand the detection range and improve the detection accuracy, a detection method of 2 rows of 15 sensors forming a one-dimensional array is adopted. In view of the fact that the size of the existing mature magnetic sensitive probes is 2mm, the spacing between adjacent magnetic sensitive probes in the same array is designed to be 2mm, and the adjacent array sensors are staggered by 2mm, so as to form a scanning detection structure without detection blind spots, and to achieve close contact between the probe and the detection surface. In addition, the rag-type magnetic sensitive sensor also has an array displacement sensor 24, which is also arranged in two rows staggered, and can be used to check the shape and size of the weld, check the defects of the weld such as misalignment, excessive excess height, and excessive edge angles, and combine with the video detection system to achieve macro inspection and shape and size inspection of the weld. The signal of the displacement sensor is coupled with the robot drive system, and the signal of the displacement sensor can be used to realize the robot tracking and walking along the weld, so as to replace the currently widely used laser tracking system, reducing weight and cost.

[0042] The magnetization and adsorption system 5 adopts a fixed yoke with a gap to realize the dual functions of magnetization and adsorption. In order to detect defects in different directions, a vertical weld magnetization fixed yoke and a parallel weld magnetization fixed yoke are required. The vertical weld magnetization fixed yoke 29 is installed between a pair of driving rubber wheels 17, and the parallel weld magnetization fixed yoke 30 is installed between a pair of universal wheels 16. The design of the front and rear outer magnetization fixed yokes meets the detection requirements of vertical and parallel weld magnetization on the one hand, and makes the adsorption force arrangement more stable on the other hand, providing sufficient downward pressure to the driving rubber wheel and the universal wheel.

[0043] like Figure 5 , Figure 6As shown, the vertical weld magnetized fixed yoke 29 includes a pair of first NS antiparallel magnets 31, a first intermediate magnetic circuit strengthening magnet 32, a ferrite soft magnetic matching magnetic bridge 33, a second mounting plate 34, and a first walking bearing 35. There is a certain gap between the fixed yoke and the wall 45 to achieve walking and climbing over obstacles, and to ensure sufficient adsorption force. A pair of first NS antiparallel magnets 31, a first intermediate magnetic circuit strengthening magnet 32, and a ferrite soft magnetic matching cross magnetic bridge 40 form a complete first magnetic circuit 37 with the wall 45 through an air gap. The ferrite soft magnetic matching magnetic bridge 33 can conduct magnetism on the one hand, and on the other hand, a threaded hole is processed on the magnetic bridge, and the first screw 48 can play the role of fixing the magnet and installing the second mounting plate 34. The first screw 48 is made of ferromagnetic material so that it basically does not affect the passage of the magnetic circuit. On the one hand, the second mounting plate 34 plays the role of fixing the protective magnet. The outer side of the bottom of the mounting plate that protects the first NS antiparallel magnet 31 has an arc surface curvature, and the first travel bearing 35 is installed to improve the obstacle-passing performance and travel performance. In addition, the second mounting plate 34 can be fixedly connected to the first mounting plate 26 of the rear rag-type magnetic sensor by bolts, so that the magnetic probe is in the middle of the magnetic yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface. There is a spring suspension system above the fixed magnetic yoke. The spring stiffness is designed so that the travel wheel just touches the wall 45 when walking on the back. At other positions, the travel wheel and the wall 45 have a certain interaction force, so that the gap between the fixed magnetic yoke and the wall 45 is basically consistent, so that it has a more consistent detection sensitivity.

[0044] like Figures 7 to 10As shown, the parallel weld magnetization fixed yoke structure uses a symmetrical cross yoke for magnetization to avoid the influence of the weld excess height, including two pairs of second NS antiparallel magnets 38, two pairs of second intermediate magnetic circuit strengthening magnets 39, second ferrite soft magnetic matching cross magnetic bridge 40, third mounting plate 41, and second walking bearing 42. There is a certain gap between the fixed yoke and the wall surface to achieve walking and climbing over obstacles, and to ensure sufficient adsorption force. The second NS antiparallel magnets 38, the second intermediate magnetic circuit strengthening magnets 39, and the ferrite soft magnetic matching cross magnetic bridge 40 form a complete second magnetic circuit 44 with the wall surface through the air gap. On the one hand, the ferrite soft magnetic matching cross-magnetic bridge 40 can conduct magnetism, and the middle part is shared by the cross-magnetic circuit. On the other hand, threaded holes are processed on the magnetic bridge, and screws can be used to fix the magnet and install the third mounting plate 41. The screws are made of ferromagnetic materials so that they basically do not affect the passage of the magnetic circuit. In addition, threaded holes can be processed in the middle part of the ferrite soft magnetic matching cross-magnetic bridge 40, and the third mounting plate 41 of the rag-type magnetic sensor is fixedly connected with the bolt, so that the magnetic sensitive probe is in the middle of the magnetic yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface. On the one hand, the third mounting plate 41 plays the role of a fixed protective magnet. The outer side of the bottom of the third mounting plate has an arc surface curvature, and a second walking bearing 42 is installed to improve the obstacle passing performance and walking performance. There is a certain gap between the fixed magnetic yoke and the wall 45 to achieve walking and climbing over obstacles, and to ensure sufficient adsorption force. The single second NS antiparallel magnet 38, the second intermediate magnetic circuit strengthening magnet 39, and the ferrite soft magnetic matching cross magnetic bridge 40 form a complete second magnetic circuit 44 with the wall through the air gap, and the cross magnetic yoke is the vector superposition of two symmetrical magnetic poles. In the middle area of ​​the cross magnetic yoke on the wall, the two magnetic fields form a vector superposition, making the magnetic field parallel to the weld, and the magnetic sensitive probe is placed in the middle of the cross magnetic yoke to obtain the leakage magnetic field information of the transverse defects on the weld surface. There is a spring suspension system above the cross fixed magnetic yoke. The spring stiffness is designed so that the walking wheel just touches the wall 45 when walking on the back. At other positions, the walking wheel has a certain interaction force with the wall, so that the gap between the fixed magnetic yoke and the wall is basically consistent, so that it has a more consistent detection sensitivity.

[0045] like Fig.11 As shown, the first mounting plate 26 on the rag-type magnetic sensor is fixedly connected to the second mounting plate 34 on the vertical weld magnetization fixed yoke 29. The second mounting plate 34 has a guide column 51, the body bracket connecting plate 50 has a sleeve 49, and a suspension spring 36 is installed between the sleeve 49 and the guide column 51. The body bracket connecting plate 50 is fixedly connected to the body bracket 13 through a second screw 52.

[0046] The first mounting plate 26 on the rear rag type magnetic sensor is fixedly connected to the third mounting plate 41 on the parallel weld magnetization fixed yoke 30. The third mounting plate 41 has a guide post 51, the body bracket connecting plate 50 has a sleeve 49, and a suspension spring 36 is installed between the sleeve 49 and the guide post 51. The body bracket connecting plate 50 is fixedly connected to the body bracket 13 through a second screw 52.

[0047] The detection robot ground station control box is used in conjunction with the robot to realize the functions of robot motion control, detection signal, and high-definition camera image return. All operations on the remote control can be completed through the ground station control box. The ground station control box consists of a display, a control panel, a power switch, an emergency stop switch, cables, a wire rack (built-in encoder), a power supply and other components.

[0048] The automatic tracking PTZ 8 can automatically identify image information. When the image moves, it follows the movement to capture the image. It can identify the movement of objects within the monitoring range and automatically control the PTZ to track the moving objects. All the movements of the objects are clearly transmitted to the monitor.

[0049] The robot has manual weld tracking and automatic weld tracking modes. In the automatic mode, the robot turns on the weld automatic tracking system. When using the system, the robot can automatically track the weld for detection operations.

[0050] The invention relates to a detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap, comprising a vehicle body, a driving system, a calibration and video detection system, a leakage magnetic field and displacement detection system, a magnetization and adsorption system, a transmission cable, a ground station control box and an automatic tracking pan-tilt platform. The leakage magnetic field and displacement detection system adopts a rag-type magnetic sensor, including a magnetic probe, an elastic rag, a spring, a displacement detection and navigation system, and multiple groups of magnetic probes are installed on the elastic rag, and the rag automatically adapts to the surface curvature of the weld of the spherical tank by relying on the spring force and the elasticity of the rag itself, and fits closely with it, so that the leakage magnetic field generated by surface and near-surface defects can be reliably detected. The rag-type magnetic sensor is also provided with a displacement sensor to check defects such as misalignment, excessive excess height, and excessive edge angles in the weld. The magnetization and adsorption system adopts a fixed magnetic yoke with a gap. The fixed magnetic yoke adopts a strong magnetic permanent magnetic material to realize the dual functions of magnetization and adsorption. There is a certain gap between the fixed magnetic yoke and the wall surface to realize walking and climbing over obstacles. For magnetization perpendicular to the weld, a pair of parallel yokes is used, and the magnetic sensitive probe is placed in the middle of the yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface. For magnetization parallel to the weld, in order to avoid the influence of the weld residual height, a symmetrical cross yoke is used for magnetization to ensure that the magnetic field in the middle area of ​​the cross yoke is parallel to the weld, and the magnetic sensitive probe is placed in the middle of the cross yoke to obtain the leakage magnetic field information of the transverse defects on the weld surface.

[0051] The specific operation process of the present invention is: the transfer robot is adsorbed onto the tank wall, and the cable reel with effective length of the cable is placed under the robot according to the working height and range, and it is ensured that the cable does not get entangled or hung during the dragging and dropping process. The automatic tracking pan-tilt head 8 is fixed in an appropriate position in the container, and the cables are connected to ensure that the equipment is turned on and operates normally, and the irradiation lamp is turned on normally. The detection path is planned, usually starting from the highest point and then step by step downward. This can avoid secondary contamination of the weld. First, the robot is controlled by the remote control to move forward, rotate, move horizontally, press down, detect and other actions, and observe whether each motion unit is working stably. Observe the video status of the front and rear cameras, the working status of the laser auxiliary system and the independent video unit through the control box, and control the movement of the robot through the control box. After each function is checked normally, the detection operation officially begins.

[0052] The robot is controlled by the control box to walk to the target weld. The automatic detection mode is usually selected. After starting, the robot automatically performs the detection operation, performs magnetization operation through the magnetization and adsorption system, detects the leakage magnetic field of the defect and the shape and size of the weld through the leakage magnetic and displacement detection system, and performs macro inspection of the weld through the calibration and video detection system. Finally, the detection information is integrated into the ground station control box of the detection robot. Through information processing, the defect information is displayed in real time on the display of the ground station control box, and the quality of the tank weld is monitored and evaluated throughout the process. The operator can also perform the detection operation manually and adjust the operation progress in real time according to the monitoring screen. And adjust the robot's forward route in real time according to the laser path guidance. The independent video unit can perform azimuth and pitch movements through the control box, which can track the robot's operation in real time and fully monitor the robot's working condition.

[0053] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap, characterized in that: It includes a vehicle body (1), a driving system (2), a calibration and video detection system (3), a magnetic flux leakage and displacement detection system (4), a magnetization and adsorption system (5), a transmission cable (6), a ground station control box (7) and an automatic tracking pan-tilt head (8) that are interconnected; The vehicle body (1) comprises a multifunctional lifting handle (9), a housing (10), a control box (11), a rear handle (12), and a body bracket (13); the multifunctional lifting handle (9) can realize a lifting function through a lifting eye screw, and can also change position through a quick plug-in pin to realize different forms, changing from a lifting bracket to a front handle, and moving the robot together with the rear handle (12); a control box (11) for controlling the drive system (2) and the calibration and video detection system (3) is also installed on the frame; the body bracket (13) is made of carbon fiber; The magnetic flux leakage and displacement detection system (4) comprises an array magnetic sensitive probe (21), an elastic rag (22), a spring (23), a displacement sensor (24), a circuit integrated board (25), a first mounting board (26), an integrated cable (27) and a signal processing system (28); a plurality of array magnetic sensitive probes (21) are arranged and mounted on the elastic rag (22), and the surfaces of the plurality of array magnetic sensitive probes (21) are indented inwardly of the elastic rag (22); The displacement sensors (24) are arranged in multiple rows in a staggered manner; The signal of the displacement sensor (24) is coupled to the robot drive system; The driving system (2) comprises a motor (14), a reducer (15), a universal wheel (16), and a driving rubber wheel (17); the driving system is driven by two motors (14) and two reducers (15) in a dual-wheel differential manner; The driving rubber wheel (17) is made of aviation aluminum and high-grade rubber, and the surface of the rubber-coated wheel is provided with grooves; the universal wheel (16) adopts a high-strength double-row plastic wheel set; The magnetization and adsorption system (5) adopts a fixed magnetic yoke with a gap to achieve the dual functions of magnetization and adsorption. In order to detect defects in different directions, a vertical weld magnetization fixed magnetic yoke (29) and a parallel weld magnetization fixed magnetic yoke (30) are provided. The vertical weld magnetization fixed magnetic yoke (29) is installed between a pair of driving rubber wheels (17), and the parallel weld magnetization fixed magnetic yoke (30) is installed between a pair of universal wheels (16). The vertical weld magnetization fixed magnetic yoke (29) includes a pair of first NS antiparallel magnets (31), a first intermediate magnetic circuit strengthening magnet (32), a ferrite soft magnetic matching magnetic bridge (33), a second mounting plate (34), a first travel bearing (35), a suspension spring, and a vertical weld magnetization fixed magnetic yoke (29). A certain gap is formed between the slot magnetized fixed magnetic yoke (29) and the wall surface to enable walking and climbing over obstacles while ensuring sufficient adsorption force. A pair of first NS antiparallel magnets (31), a first intermediate magnetic circuit reinforcing magnet (32), and a ferrite soft magnetic matching magnetic bridge (33) form a complete first magnetic circuit (37) with the wall surface through an air gap. The ferrite soft magnetic matching magnetic bridge (33) can conduct magnetism on the one hand, and on the other hand, threaded holes are machined on the magnetic bridge. The first screws (48) can play the role of fixing the magnets and installing the second mounting plates (34) on both sides. The first screws (48) are made of ferromagnetic material so that they basically do not affect the passage of the magnetic circuit. The second mounting plates (34) play the role of fixing and retaining on the one hand. The outer side of the bottom of the mounting plate of the first NS antiparallel magnet (31) has a circular arc curvature, and a first walking bearing (35) is installed to improve obstacle crossing performance and walking performance. In addition, the second mounting plate (34) is fixedly connected to the first mounting plate (26) of the rag-type magnetic sensor by bolts, so that the magnetic probe is in the middle of the magnetic yoke to obtain leakage magnetic field information of longitudinal defects on the weld surface; a suspension spring is provided above the fixed magnetic yoke, and the spring stiffness is designed so that the walking wheel just touches the wall (45) when walking on the back, and there is a certain interaction force between the walking wheel and the wall (45) at other positions, so that the gap between the fixed magnetic yoke and the wall (45) is basically consistent, so that it has a more consistent detection Sensitivity measurement; the parallel weld magnetization fixed yoke (30) is magnetized by a symmetrical cross yoke to avoid the influence of the weld excess height, and includes two pairs of second NS antiparallel magnets (38), two pairs of second intermediate magnetic circuit strengthening magnets (39), a ferrite soft magnetic matching cross magnetic bridge (40), a third mounting plate (41), a second walking bearing (42), and a suspension spring; a certain gap is formed between the fixed yoke and the wall surface (45) to achieve walking and climbing over obstacles, while ensuring sufficient adsorption force; the second NS antiparallel magnets (38), the second intermediate magnetic circuit strengthening magnets (39), and the ferrite soft magnetic matching magnetic bridge (33) form a complete second magnetic circuit (44) with the wall surface through an air gap;On the one hand, the ferrite soft magnetic matching cross magnetic bridge (40) can conduct magnetism, and the middle part is shared by the cross magnetic circuit. On the other hand, a threaded hole is processed on the ferrite soft magnetic matching magnetic bridge (33), and the screw can play the role of fixing the magnet and the third mounting plate (41). The screw is made of ferromagnetic material so that it basically does not affect the passage of the magnetic circuit. In addition, a threaded hole is processed in the middle part of the ferrite soft magnetic matching cross magnetic bridge (40), and is fixedly connected to the first mounting plate (26) of the rag-type magnetic sensor through bolts, so that the magnetic sensitive probe is in the middle of the magnetic yoke to obtain the leakage magnetic field information of the longitudinal defects on the weld surface; the first mounting plate (26) plays the role of fixing the protective magnet, and the outer side of the bottom of the mounting plate has a circular arc curvature, and a second walking bearing (42) is installed to improve the obstacle passing performance and walking performance; there is a certain gap between the fixed magnetic yoke and the wall (45) to achieve walking and climbing over obstacles, and to ensure sufficient adsorption force. ; 2. The detection robot based on a rag-type magnetic sensor and a fixed magnetic yoke with a gap according to claim 1 is characterized in that: The calibration and video detection system (3) comprises a front camera system (18), a front lighting lamp (19) and a laser aligner (20). The calibration and video detection system (3) is installed in front of the wall-climbing walking mechanism, and emits two laser beams on both sides of the weld to facilitate alignment of the weld, so that the robot can walk along the weld and observe the situation in front of the robot.

3. The detection robot based on the rag-type magnetic sensor and the fixed magnetic yoke with a gap according to claim 1 is characterized in that: A first mounting plate (26) on the rag-type magnetic sensor and a second mounting plate (34) on the vertical weld magnetization fixed yoke (29) are fixedly connected; a guide column (51) is provided on the second mounting plate (34), a sleeve (49) is provided on the main body bracket connecting plate (50), a suspension spring is installed between the sleeve (49) and the guide column (51), and the main body bracket connecting plate (50) is fixedly connected to the main body bracket (13) by screws.

4. The detection robot based on the rag-type magnetic sensor and the fixed magnetic yoke with a gap according to claim 1 is characterized in that: The fourth mounting plate (53) on the rear rag-type magnetic sensor is fixedly connected to the third mounting plate (41) on the parallel weld magnetization fixed yoke (30); the third mounting plate (41) is provided with a guide column (51), the main body bracket connecting plate (50) is provided with a sleeve (49), a suspension spring is installed between the sleeve (49) and the guide column (51), and the main body bracket connecting plate (50) is fixedly connected to the main body bracket (13) by screws.

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