Shield hob snap ring intelligent welding device and method based on visual positioning

Abstract

The invention discloses a shield hob snap ring intelligent welding device and method based on visual positioning, and relates to the technical field of intelligent welding systems. A shield hob snap ring intelligent welding device based on visual positioning comprises a central controller, and a foundation structure and circulation system, an intelligent visual and positioning system, an integrated welding execution system and an environment protection system which are electrically connected with the central controller. The base structure and circulation system comprises a welding platform, a linear slide way assembly arranged on the welding platform and clamping assemblies symmetrically arranged on the two sides of a linear slide way. According to the shield hob snap ring intelligent welding device and method based on visual positioning, the position of a welding spot is intelligently recognized through a binocular vision system, self-adaptive centering clamping based on force control is combined, the accuracy and stability of the assembly state before welding are ensured, the welding path and parameters are uniformly planned and executed by the central controller, and the welding efficiency is improved. And the uncertainty of manual operation is eliminated.

Description

Intelligent Welding Device and Method for Shield Tunneling Roller Cutter Clamping Ring Based on Vision Positioning Technical Field

[0001] This invention relates to the field of intelligent welding system technology, and in particular to an intelligent welding device and method for shield tunneling cutter clamping rings based on vision positioning. Background Technology

[0002] The single-edged cutterhead of a tunnel boring machine (TBM) is a critical rock-breaking component. Its cutterhead ring is engaged with the cutter hub via two semi-annular retaining rings, and then welded at the connection points and the middle of the retaining rings, typically at four weld points. The quality of this welding process directly determines the structural reliability of the cutterhead under extreme tunneling loads. The production method for this process has the following main drawbacks:

[0003] Current technologies mostly employ manual positioning, handheld welding torches, or semi-automatic equipment for welding. Welding quality is greatly affected by the operator's skill level and fatigue level, making it difficult to guarantee consistency in penetration depth, strength, and appearance among the four weld points. This easily leads to defects such as incomplete welds, overheating, or undercut, posing safety hazards for tunnel boring machine (TBM) construction.

[0004] The lack of effective automatic positioning and alignment methods makes it difficult to effectively detect and correct the initial assembly gap and eccentricity between the retaining ring and the tool hub before welding. This results in inconsistent welding references, affecting the final assembly accuracy and uniformity of stress distribution.

[0005] The manual loading, unloading, positioning, and welding processes are cumbersome and inefficient. The large amount of smoke and intense arc light generated during welding poses a threat to the operator's health, and traditional local exhaust ventilation has limited effectiveness in dust removal, resulting in a poor working environment. Summary of the Invention

[0006] The purpose of this invention is to provide an intelligent welding device and method for shield tunnel cutter clamping rings based on vision positioning. By intelligently identifying the weld point position through a binocular vision system and combining it with force-controlled adaptive centering clamping, the device ensures the accuracy and stability of the assembly state before welding. The welding path and parameters are uniformly planned and executed by a central controller, which completely eliminates the uncertainty of manual operation and makes the quality of the four weld points highly consistent. This greatly improves the overall structural strength and reliability of the cutter, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: an intelligent welding device for shield tunnel cutter clamping rings based on visual positioning, comprising:

[0008] The central controller, and the infrastructure and circulation system electrically connected to the central controller, the intelligent vision and positioning system, the integrated welding execution system, and the environmental protection system;

[0009] The basic structure and transfer system includes a welding platform, a linear slide assembly set on the welding platform, and clamping assemblies symmetrically arranged on both sides of the linear slide.

[0010] The linear slide rail assembly includes a slide rail mounting plate, a first slide rail, a sliding plate, and a first cylinder. The slide rail mounting plate is mounted on a welding platform. Symmetrical first slide rails are mounted on the slide rail mounting plate. One end of the slide rail mounting plate extends out of the welding platform, and the other end of the slide rail mounting plate is provided with a first cylinder. The clamping assembly includes a mounting base, a second slide rail fixed on the mounting base, a second cylinder provided on the mounting base, and a movable plate provided on the second slide rail. The front end of the movable plate is provided with a clamping groove for clamping and centering the retaining ring from both sides.

[0011] The intelligent vision and positioning system includes a binocular vision sensor mounted on top of the protective cover for identifying the location of the weld points, and an infrared laser device for assisting in the coarse positioning of the workpiece.

[0012] The integrated welding execution system includes a welding robotic arm mounted on a welding platform;

[0013] The environmental protection system includes a protective cover that encloses the welding station, with an exhaust port at the top of the cover that connects to a central welding fume purifier.

[0014] Furthermore, limiters are provided at both ends of the slide mounting plate. The limiters are positioned opposite the slide plate and can restrict the movement of the slide plate, including limiting the initial position and the final position of the slide plate. The upper surface of the slide plate is provided with a locking position for fixing the axial direction of the single-blade hob.

[0015] Furthermore, the locking position includes a rotating platform and a support platform. The rotating platform is rotatably fitted onto the support platform, and the support surface of the rotating platform is provided with a protective pad. One side of the support platform is provided with an elastically retractable positioning pin, which is used to cooperate with the positioning hole of the single-blade hob end cap to prevent it from rotating.

[0016] Furthermore, the positioning pin is located in the spring groove of the support platform via a support spring, and an adjusting bolt is provided in the middle of the positioning pin to adjust its extension height.

[0017] Furthermore, a pull plate is connected to the output end of the first cylinder.

[0018] Furthermore, the movable plate includes a guide plate and a clamping plate. The clamping plate is mounted on the guide plate. The lower surface of the guide plate is movably connected to the second slide rail via a slider. Guide slots are symmetrically arranged on both sides of the guide plate. A collection box is provided on the welding platform below the guide slots. A sensor mounting slot is opened in the clamping plate, and an acoustic emission sensor is embedded in the mounting slot. An ultrasonic coupling agent is coated between the acoustic emission sensor and the clamping plate to ensure signal transmission. The sensor is connected to the acoustic emission acquisition module of the central controller via a shielded cable.

[0019] Furthermore, one end of the clamping plate is provided with a clamping groove, which is a trapezoidal structure. The long base side of the trapezoid is open, and the inclined side of the trapezoid contacts the retaining ring for clamping the position of the retaining ring.

[0020] Another technical problem to be solved by the present invention is to provide a method for using a vision-based intelligent welding device for shield tunnel cutter clamps, comprising the following steps:

[0021] S1: At the preparatory station, place the single-edged hob on the slot of the slide plate, perform coarse positioning with the help of an infrared laser device, and fix it circumferentially with a positioning pin.

[0022] S2: Control the first cylinder to send the slide plate carrying the workpiece into the welding station;

[0023] S3: Identify the workpiece using a binocular vision sensor and calculate the weld point coordinates and circumferential eccentricity.

[0024] S4: Control the clamping components on both sides to perform asymmetrical clamping according to the eccentricity, center and fix the retaining ring;

[0025] S5: Control the welding robotic arm to weld according to the welding point coordinates, and at the same time start the central welding fume purifier to treat the fumes.

[0026] S6: After welding is completed, a silent inspection is performed to check for welding defects. If there are no defects, proceed to the next process; if there are defects, locate the defect.

[0027] S7: Repair the defect by welding and perform a second silent inspection.

[0028] Furthermore, in step S3, calculating the eccentricity of the retaining ring specifically includes: fitting the cylindrical surface of the tool hub to determine its axis, identifying the retaining ring profile to calculate its center, and calculating the positional deviation between the two in a plane perpendicular to the axis.

[0029] Furthermore, in step S4, asymmetric clamping means: according to the eccentric direction, controlling the opposing clamping components on the biased side of the circlip to provide greater propulsion force or earlier contact.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. This invention uses a binocular vision system to intelligently identify the position of the welding point and combines it with force-controlled adaptive centering clamping to complete the assembly of the intelligent welding system. This ensures the accuracy and stability of the assembly state before welding. The welding path and parameters are uniformly planned and executed by the central controller, eliminating the uncertainty of manual operation. This ensures that the quality of the four welding points of the shield cutter head retainer is consistent, thereby improving the overall structural strength and reliability of the shield cutter head.

[0032] 2. This invention integrates intelligent units such as visual measurement, laser-assisted positioning, and force-controlled clamping. The system can automatically identify shield cutter head shackles, measure assembly errors, and actively perform corrective actions, reducing the operator's reliance on experience.

[0033] 3. This invention achieves separation of assembly and welding through an automatic sliding plate transfer system, shortening the welding time of a single shield cutter clamping ring and improving production efficiency; the fully enclosed protective cover is linked with the central welding fume purification system to form an effective sealed negative pressure space during welding, which can capture and purify welding fumes and harmful gases in real time and efficiently. The integration of automatic repair welding function allows defects to be repaired instantly at the same work station and in the same clamping state, avoiding the rework costs caused by discovering defects after the shield cutter has been transferred to subsequent processes. Attached Figure Description

[0034] Figure 1 is a block diagram of the overall structure of the intelligent welding device for shield tunneling cutter clamping ring based on visual positioning according to the present invention;

[0035] Figure 2 is a structural diagram of the welding platform of the present invention;

[0036] Figure 3 is a top view of the straight slide rail of the present invention;

[0037] Figure 4 is a structural diagram of the straight slide rail of the present invention;

[0038] Figure 5 is a cross-sectional view of the sliding plate of the present invention;

[0039] Figure 6 is an overall structural diagram of the clamping assembly of the present invention;

[0040] Figure 7 is a partial structural diagram of the clamping component of the present invention;

[0041] Figure 8 is a structural diagram of the internal structure of the protective cover of the present invention.

[0042] In the diagram: 1. Welding platform; 2. Straight slide; 21. Slide mounting plate; 211. Limiter; 22. First slide; 23. Slide plate; 231. Rotary groove; 232. Rotary table; 2321. Protective pad; 233. Support platform; 2331. Spring groove; 2332. Positioning pin; 2333. Support spring; 2334. Adjusting bolt; 24. First cylinder; 241. Pull plate; 3. Clamping assembly; 31. Mounting base; 32. Second slide; 33. Second cylinder; 34. Movable plate; 341. Guide plate; 3411. Guide slot; 342. Clamping plate; 3421. Clamping groove; 35. Collection box; 4. Binocular vision sensor; 5. Infrared laser device; 6. Welding robotic arm; 7. Protective cover; 71. Window; 72. Smoke vent. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please refer to Figures 1-8. The intelligent welding device for shield tunnel cutter clamping ring based on vision positioning includes a basic structure and circulation system, an intelligent vision and positioning system, an integrated welding execution system, and an environmental protection system. The basic structure and circulation system, the intelligent vision and positioning system, the integrated welding execution system, and the environmental protection system are all connected to a central controller. The central controller transmits information and issues instructions to each subsystem. The basic structure and circulation system includes a welding platform 1, a linear slide assembly 2 set on the welding platform 1, and clamping assemblies 3 symmetrically set on both sides of the linear slide 2. The intelligent vision and positioning system includes a binocular vision sensor 4 for identifying the weld point position and workpiece features and an infrared laser device 5 for auxiliary positioning. The integrated welding execution system includes a welding robotic arm 6 set on the welding platform 1. The environmental protection system includes a protective cover 7 set on the welding platform 1.

[0045] Specifically, the linear slide assembly 2 includes a slide mounting plate 21, a first slide 22, a slide plate 23, and a first cylinder 24. The slide mounting plate 21 is mounted on the welding platform 1. Symmetrical first slides 22 are mounted on the slide mounting plate 21. One end of the slide mounting plate 21 extends out of the welding platform 1, and the other end of the slide mounting plate 21 is provided with a first cylinder 24. The output end of the first cylinder 24 is connected to a pull plate 241, and the other end of the first cylinder 24 is fixed on the welding platform 1. The first cylinder 24 controls the movement of the pull plate 241, thereby moving the slide plate 23 on the first slide 22. The slide plate 23 is movably connected to the first slide 22 through a slider provided on its lower surface. In addition, limiters 211 are provided at both ends of the slide mounting plate 21. The position of the limiters 211 is opposite to that of the slide plate 23, which can limit the movement of the slide plate 23, including limiting the initial position and the final position of the slide plate 23. A locking position is provided on the upper surface of the slide plate 23 for fixing the axial direction of the single-edged hob.

[0046] It is important to understand that the mounting position includes a rotating groove 231 formed on the slide plate 23, a rotating platform 232 installed in the rotating groove 231, and a support platform 233 set in the rotating groove 231. The support platform 233 is sleeved with the rotating platform 232, and the rotating platform 232 rotates along the support platform 233 to change the position of the single-edged hob. A protective pad 2321 is installed on the support surface of the rotating platform 232. The protective pad 2321 contacts the single-edged hob and is used to support the single-edged hob. The protective pad 2321 can prevent the single-edged hob from being scratched. The contact surface between the support platform 233 and the rotating platform 232 is connected by a smooth surface or by a bearing to improve the lubrication of rotation. A spring is provided on one side of the support platform 233. A spring groove 2331 is provided, and a positioning pin 2332 is provided inside the spring groove 2331. A support spring 2333 is provided at the lower end of the positioning pin 2332. The lower end of the support spring 2333 is connected to the spring groove 2331. An adjusting bolt 2334 is provided in the middle of the positioning pin 2332. The adjusting bolt 2334 passes through the positioning pin 2332 and engages with the bottom of the spring groove 2331. By turning the adjusting bolt 2334, the height of the adjusting bolt 2334 can be set. When the adjusting bolt 2334 is higher than the support platform 233 under the support of the support spring 2333, it can extend into the positioning hole of the end cap of the single-edged hob end face to fix the position of the single-edged hob and prevent the single-edged hob from rotating axially.

[0047] Furthermore, the clamping assembly 3 includes a mounting base 31, a second slide rail 32 fixed on the mounting base 31, a second cylinder 33 disposed on the mounting base 31, and a movable plate 34 disposed on the second slide rail 32. The output end of the second cylinder 33 is connected to the movable plate 34, and the movable plate 34 is moved along the second slide rail 32 by the second cylinder 33. The two symmetrical clamping assemblies 3 fix the retaining rings on both sides of the single-edged hob. The second slide rail 32 is horizontally mounted on the mounting base 31 and its direction is perpendicular to the workpiece axis. When the second cylinder 33 is working, it drives the movable plate 34 to move along the second slide rail 32, thereby changing the clamping diameter and clamping tightness of the movable plate 34.

[0048] More specifically, the movable plate 34 includes a guide plate 341 and a clamping plate 342. The clamping plate 342 is mounted on the guide plate 341. The lower surface of the guide plate 341 is movably connected to the second slide rail 32 via a slider. Guide slots 3411 are symmetrically arranged on both sides of the guide plate 341. A collection box 35 is provided on the welding platform 1 below the guide slots 3411. The guide plate 341 collects the welding slag generated during welding and concentrates the welding slag into the collection box 35 through the guide slots 3411. A clamping groove 3421 is opened at one end of the clamping plate 342. The clamping groove 3421 has a trapezoidal structure. One side of the long base of the trapezoid is an open structure. The inclined side of the trapezoid contacts the retaining ring and is used to clamp the retaining ring.

[0049] On the back of the clamping plate 342, a sensor mounting slot is provided. An acoustic emission sensor is embedded in the slot. An ultrasonic coupling agent is coated between the sensor and the clamping plate 342 to ensure signal transmission. The sensor is connected to the acoustic emission acquisition module of the central controller via a shielded cable. The frequency of the welding crack signal is mainly concentrated between 110kHz and 190kHz. Therefore, the acoustic emission sensor selected has a resonant frequency of 150kHz, a sampling rate ≥1MHz, and a preamplifier gain of 40dB. Two to four acoustic emission sensors are set. The preamplifier is installed on the outside of the protective cover 7. The acoustic emission acquisition card is integrated into the central controller, and an algorithm unit is added to the central controller as a signal processing module. The signal acquisition process is as follows: after welding is completed and before the clamping component 3 is released, a silent detection phase is inserted, lasting about 5 to 10 seconds. All moving mechanisms inside the protective cover 7 are paused, and the acoustic emission signal during the weld cooling process is collected. The collected signal is amplified, filtered, and its features are extracted. The central controller compares the real-time acquired acoustic emission signal with a pre-stored acoustic emission feature database of welding defects. The database contains acoustic emission characteristic templates for three typical defects: 1. Crystallization cracks (high frequency, high energy, sudden burst); 2. Cold cracks (low frequency, continuous); 3. Porosity / slag inclusions (medium frequency, short-term sudden burst). If any parameter of the real-time signal amplitude, energy, or ring count exceeds a preset threshold, and the peak frequency falls within the range of 100kHz to 200kHz, the weld joint is determined to have an internal defect. When the defect generates an acoustic emission signal, the time it takes for the signal to propagate to different sensors varies slightly (Δt). The central controller calculates the three-dimensional spatial coordinates of the defect on the weld by solving a system of hyperbolic equations based on the known distance d between the sensors and the propagation speed v of the sound wave in the steel. The positioning accuracy can reach ±5mm. The central controller automatically generates a repair welding path based on the defect positioning coordinates. The repair welding path is based on the center of the original weld point, covering the defect area, and is a circular or short straight trajectory with a diameter of 2-3mm. The welding robotic arm 6 restarts, driving the welding torch to move to the defect coordinates, and performs secondary remelting repair according to the preset repair welding process parameters (10%-15% lower than normal welding current, and slightly slower speed). After the repair welding is completed, a secondary acoustic emission test is performed on the repaired area to verify whether the defect has been eliminated. If the defect signal is still present, it is marked as an abnormal workpiece and an alarm is triggered.

[0050] It is important to understand that the protective cover 7 is a metal frame enclosure that completely covers the upper space of the welding platform 1. Windows 71 are provided on all four sides of the protective cover 7, and can be opened for inspecting the welding platform 1 or for the single-edged hobbing cutter to enter or exit. During welding, the windows 71 are closed to prevent dust and smoke. An exhaust vent 72 is located at the top of the protective cover 7, connected to a dust extraction pipe. Under the control of the environmental protection system, the exhaust vent 72 can be controlled to absorb and treat the welding fumes inside the protective cover 7. Before welding begins, all windows 71 must be closed, creating a relatively sealed space within the protective cover 7. The welding program start signal will trigger the activation of an external central welding fume purifier. The central welding fume purifier has a built-in high-power fan, connected to the exhaust vent 72 at the top of the protective cover 7 via a pipe, generating a stable negative pressure airflow inside the cover. The welding fumes, mainly metal oxide particles, rise under heat and are effectively captured by the negative pressure airflow from the top exhaust vent 72, then extracted from the protective cover 7 through the pipe.

[0051] The binocular vision sensor 4 is installed at the top inside the protective housing 7. The binocular vision sensor 4 uses an industrial-grade binocular stereo vision camera, consisting of two precisely calibrated high-definition CMOS / CCD cameras, a built-in or external processor, and a robust protective housing. Brands such as Hikvision Robotics, Daheng Imaging, Basler, and FLIR all have mature products available. The binocular vision sensor 4 should be directly facing the welding station, ensuring that after the single-edged hob on the slide plate 23 enters, its entire retaining ring area is centered and clear in the field of view. The installation angle is slightly tilted to avoid interference with the top lighting or hoisting equipment of the protective housing 7. A high-strength anti-splash glass must be installed in front of the lens of the binocular vision sensor 4, and an air curtain should be used to protect against smoke and heat, ensuring lens cleanliness and camera cooling. A uniform and stable ring-shaped white LED light source should be integrated around the camera at the top of the protective housing 7 to provide a shadowless, high-contrast lighting environment for visual recognition. Binocular vision sensor 4 simultaneously captures images of the positioned hobbing cutter assembly from different angles. The processor uses a stereo matching algorithm to calculate the pixel difference of the same physical point in the two images. Combining this with camera intrinsic parameters, it calculates the three-dimensional coordinates (X, Y, Z) of that point. By calculating the parallax of the same physical point in the two images, based on the principle of triangulation, it generates three-dimensional point cloud data of the workpiece welding area. This point cloud accurately represents the three-dimensional spatial information of key features such as the cutter hub, retaining ring, and retaining ring seam. Thousands of such points constitute the three-dimensional point cloud model of the workpiece. The software algorithm fits the cylindrical surface of the cutter hub and the contour of the retaining ring into the point cloud, thereby calculating the center of both, the seam position, and the precise three-dimensional coordinates of the four target welding points. These coordinates are sent to the controller of the welding robot arm 6 via Ethernet to guide the movement of the welding torch. In addition, the axis of the cutter hub is projected onto a plane perpendicular to its axis to obtain a point; the center of the retaining ring is also projected onto the same plane to obtain another point. The Euclidean distance between these two projected points is calculated, and this distance is the eccentricity of the retaining ring. The direction of the line connecting these two points is the eccentricity direction. The calculation results will be sent to the control unit of the clamping component (3) in real time. The central controller will bind the visual recognition results of each welding (including weld point coordinates, eccentricity, eccentricity direction) and welding parameters (current, voltage, speed) and store them in the local database or upload them to the factory management system to achieve full traceability of the welding process.

[0052] The infrared laser device 5 is installed in the middle of one side of the protective cover 7, directly facing the first slide rail 22. The infrared laser device 5 uses an infrared laser projector; to enhance the effect, a crosshair laser is often selected, providing both horizontal and vertical reference lines. The laser is fixedly installed, projecting the laser line vertically onto the center area of ​​the slide rail 23 at the welding station. When the operator loads the workpiece, by observing the position of the laser line on the end face of the hob hub, the operator manually fine-tunes the single-edged hob, ensuring that the laser line simultaneously passes through the center of both ends of the hub, achieving rapid coarse positioning of the workpiece and initially placing it within the effective measurement range of the vision system.

[0053] The working method of the intelligent welding device for shield tunnel cutter clamping rings based on vision positioning specifically includes the following steps:

[0054] Step 1: System preparation and workpiece loading

[0055] The operator turns on the main power supply of the device, the central controller starts, and all subsystems are in standby mode. The operator confirms that all windows 71 of the protective cover 7 are open for easy operation. The operator moves the single-edged hobbing cutter assembly, with the retaining rings pre-attached, to the preparatory station outside the welding platform 1. The hobbing cutter hub end face is placed on the protective pad 2321 of the rotary table 232 on the slide plate 23. By observing the cross laser lines projected by the infrared laser device 5 onto the two end faces of the hobbing cutter hub, the operator manually fine-tunes the hobbing cutter on the rotary table 232. The circumferential position of the laser line allows the vertical line to pass through the visual center of both ends of the workpiece as simultaneously as possible, thus achieving rapid rough positioning of the workpiece. If it is necessary to prevent the hob from rotating during the process, the rotating table 232 is rotated, the support table 233 is fixed in position, and the positioning pin 2332 is pressed into the spring groove 2331 by the single-edged hob. The positioning hole of the rotating single-edged hob end cap rotates continuously until the positioning pin 2332 is aligned with the positioning hole. Under the action of the support spring 2333, the positioning pin 2332 is pushed into the positioning hole to achieve circumferential fixation.

[0056] Step Two: Automated Workpiece Flow and Precise Positioning

[0057] When the operator leaves the work area, he issues a "loading" command through the control panel. The first cylinder 24 is activated, and the slide plate 23 carrying the workpiece is driven by the pull plate 241 to slide smoothly from the external preparatory station into the welding station inside the protective cover 7 along the first slide rail 22 until the slide plate 23 touches and triggers the limiter 211 of the welding station, and the system receives a "positioned" signal.

[0058] Step 3: Intelligent visual recognition and solder joint positioning

[0059] Once the slide plate 23 is in place, the ring-shaped LED light source on top of the protective cover 7 illuminates, providing optimal illumination for the binocular vision sensor 4. The binocular vision sensor 4 simultaneously captures high-definition images of the hobbing cutter assembly from two different angles. The built-in processor uses a stereo vision algorithm to generate a high-precision 3D point cloud model including the cutter hub and retaining ring. The vision processing software automatically analyzes the point cloud and performs the following core calculations:

[0060] Fit the cylindrical surface of the tool hub and determine its spatial axis;

[0061] Identify and segment the outer contour of the clasp, and calculate its center position;

[0062] By comparing the position of the tool hub axis with the center of the retaining ring, the system can automatically determine whether the retaining ring is eccentric.

[0063] Regardless of the position of the retaining ring, the system can accurately identify the two seams of the two semi-circular retaining rings and calculate the absolute three-dimensional coordinates of the four welding points in space.

[0064] Step 4: Clamping and self-adaptive centering of the retaining ring

[0065] The vision system sends the calculated circlip eccentricity to the central controller. The controller instructs the clamping components 3 on both sides to perform asymmetrical movements. The second cylinder 33 precisely controls the advancing distance of the movable plates 34 on both sides based on the eccentricity data. For example, if the circlip is biased to the right, the left cylinder advances more and the right cylinder advances less. The trapezoidal clamping groove 3421 at the front end of the movable plate 34 contacts and grips the circlip. Due to the uneven thrust on both sides, a resultant torque is generated during the clamping process to "push" the circlip towards the center, automatically correcting the circlip eccentricity and making it coaxial with the blade hub axis. After alignment, the clamping forces on both sides are balanced, firmly fixing the circlip in the ideal position that is closely fitted with the blade hub. The system pressure sensor reports that the clamping force meets the standard, preparing for welding.

[0066] Step 5: Automated Welding and Simultaneous Environmental Protection Processing

[0067] The central controller sends the coordinates of the four welding points provided by the vision system to the welding robot arm 6 and automatically plans the optimal welding path. At the same time as the welding program starts, the central controller activates the external central welding fume purifier, and the high-power fan starts working. A stable negative pressure airflow is formed inside the protective cover 7 through the top exhaust port 72. The welding robot arm 6 drives the welding torch to move precisely to the four predetermined welding points in sequence and automatically completes the welding operation according to the preset process parameters. During the entire welding process, the roller cutter is fixed by the clamping component 3 and remains stationary. The fumes and spatter generated by welding rise under the action of the hot airflow and are immediately captured by the negative pressure airflow of the top exhaust port 72. The welding slag falls into the collection box 35 below through the guide slot 3411 of the guide plate 341.

[0068] Step Six: After the welding robotic arm 6 completes the welding of four weld points and returns to its original position, the clamping assembly 3 continues to maintain the clamping state. The central controller starts the post-weld acoustic emission detection program. The acoustic emission sensors embedded in the clamping plates 342 on both sides enter the listening mode. During the 5-10 seconds of natural cooling of the weld, acoustic emission signals that may be released by internal defects are continuously collected. The collected signals are amplified by the preamplifier and sent to the acoustic emission processing module of the central controller. This module first performs bandpass filtering on the signal to filter out low-frequency mechanical vibration and environmental noise interference. Then, it extracts characteristic parameters such as the amplitude, ring count, energy and peak frequency of the signal and compares them with the pre-stored acoustic emission feature database of welding defects in real time. When any characteristic parameter of the real-time signal exceeds the preset threshold and the matching degree with any defect template exceeds 80%, the central controller determines that there is an internal defect in the weld point.

[0069] Step Seven:

[0070] When a defect is detected, the central controller initiates the defect location algorithm. Let the distance between the two acoustic emission sensors on the left and right clamping assemblies be D, and the speed of sound propagation in steel be v. The central controller calculates the time difference Δt between the arrival of the same defect signal at the two sensors. Then, the perpendicular distance x between the defect's position on the weld and the line connecting the two sensors satisfies the following relationship: ,

[0071] Using this algorithm, the system can determine the specific coordinates of defects in the weld area with millimeter-level accuracy. The central controller automatically generates a repair welding path based on the defect coordinates. The repair welding path is a circular or spiral trajectory covering the defect area, with a diameter of 2-3 mm. Subsequently, the central controller drives the welding robotic arm 6 to move to the defect coordinates again and performs secondary remelting repair according to the repair welding process parameters. After the repair welding is completed, the system automatically repeats the acoustic emission detection in step six to verify the repaired area. If the secondary detection still detects a defect signal, the central controller issues an audible and visual alarm on the HMI interface, prompting that the workpiece requires manual intervention; if there is no defect signal, the workpiece is marked as qualified and enters the subsequent process.

[0072] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A vision-based intelligent welding device for shield tunnel cutter clamping rings, characterized in that, include: The central controller, and the infrastructure and circulation system electrically connected to the central controller, the intelligent vision and positioning system, the integrated welding execution system and the environmental protection system; the infrastructure and circulation system includes a welding platform (1), a linear slide assembly (2) set on the welding platform (1), and clamping assemblies (3) symmetrically set on both sides of the linear slide (2); the linear slide assembly (2) includes a slide mounting plate (21), a first slide (22), a slide plate (23) and a first cylinder (24), the slide mounting plate (21) is installed on the welding platform (1), the slide mounting plate (21) is equipped with symmetrical first slides (22), one end of the slide mounting plate (21) extends out of the welding platform (1), and the other end of the slide mounting plate (21) is equipped with a first cylinder (24) for clamping. The holding component (3) includes a mounting base (31), a second slide rail (32) fixed on the mounting base (31), a second cylinder (33) set on the mounting base (31), and a movable plate (34) set on the second slide rail (32). The movable plate (34) has a clamping groove (3421) at the front end for clamping and centering the retaining ring from both sides. The intelligent vision and positioning system includes a binocular vision sensor (4) installed on the top of the protective cover (7) for identifying the position of the weld point, and an infrared laser device (5) for assisting in the coarse positioning of the workpiece. The integrated welding execution system includes a welding robotic arm (6) set on the welding platform (1). The environmental protection system includes a protective cover (7) covering the welding station. The top of the protective cover (7) has a smoke exhaust port (72) connected to the central welding fume purifier.

2. The intelligent welding device for shield tunneling cutter clamping ring based on vision positioning according to claim 1, characterized in that, Limiters (211) are provided at both ends of the slide mounting plate (21). The position of the limiters (211) is opposite to the slide plate (23), which can restrict the movement position of the slide plate (23), including limiting the initial position and the final position of the slide plate (23). The upper surface of the slide plate (23) is provided with a locking position for fixing the axial direction of the single-blade hob.

3. The intelligent welding device for shield tunneling cutter clamping ring based on vision positioning according to claim 2, characterized in that, The locking position includes a rotating platform (232) and a support platform (233). The rotating platform (232) is rotatably fitted onto the support platform (233). The support surface of the rotating platform (232) is provided with a protective pad (2321). One side of the support platform (233) is provided with a retractable positioning pin (2332) for engaging with the positioning hole of the single-blade hob end cap to prevent it from rotating.

4. The intelligent welding device for shield tunneling cutter clamping ring based on vision positioning according to claim 3, characterized in that, The positioning pin (2332) is located in the spring groove (2331) of the support platform (233) via the support spring (2333), and the positioning pin (2332) is provided with an adjusting bolt (2334) in the middle for adjusting its extension height.

5. The intelligent welding device for shield tunneling cutter clamping ring based on vision positioning according to claim 1, characterized in that, The output end of the first cylinder (24) is connected to a pull plate (241).

6. The intelligent welding device for shield tunneling cutter clamping ring based on vision positioning according to claim 1, characterized in that, The movable plate (34) includes a guide plate (341) and a clamping plate (342). The clamping plate (342) is mounted on the guide plate (341). The lower surface of the guide plate (341) is movably connected to the second slide rail (32) through a slider. Guide slots (3411) are symmetrically arranged on both sides of the guide plate (341). A collection box (35) is provided on the welding platform (1) below the guide slots (3411). A sensor mounting slot is opened in the clamping plate (342), and an acoustic emission sensor is embedded in the mounting slot.

7. The intelligent welding device for shield tunneling cutter clamping ring based on vision positioning according to claim 6, characterized in that, The clamping plate (342) has a clamping groove (3421) at one end. The clamping groove (3421) is a trapezoidal structure with an open structure on one side of the long base of the trapezoid. The inclined side of the trapezoid contacts the retaining ring and is used to clamp the position of the retaining ring.

8. A working method of the intelligent welding device for shield tunneling cutter clamping ring based on vision positioning as described in claim 1, characterized in that, Includes the following steps: S1: At the preparatory station, place the single-edged hob on the slot of the slide plate (23), perform coarse positioning with the help of the infrared laser device (5), and fix it circumferentially with the positioning pin (2332); S2: Control the first cylinder (24) to send the slide plate (23) carrying the workpiece into the welding station; S3: Identify the workpiece through the binocular vision sensor (4), calculate the coordinates of the weld point and the eccentricity of the retaining ring; S4: Control the clamping components (3) on both sides to perform asymmetrical clamping according to the eccentricity, center and fix the retaining ring; S5: Control the welding robot arm (6) to perform welding according to the coordinates of the weld point, and at the same time start the central welding fume purifier to treat the fume; S6: After welding is completed, perform a silent inspection to check whether there are welding defects. If there are no defects, proceed to the next process. If there are defects, locate the defect position; S7: Repair the defects by welding and perform a second silent inspection.

9. The working method of the intelligent welding device for shield tunnel cutter clamping ring based on vision positioning according to claim 8, characterized in that, In step S3, calculating the eccentricity of the retaining ring specifically includes: fitting the cylindrical surface of the tool hub to determine the axis, identifying the retaining ring profile to calculate the center, and calculating the positional deviation between the two in a plane perpendicular to the axis.

10. The working method of the intelligent welding device for shield tunnel cutter clamping ring based on vision positioning according to claim 8, characterized in that, In step S4, asymmetric clamping means that, according to the eccentric direction, the opposing clamping assembly (3) on the biased side of the circlip provides greater propulsion or earlier contact.

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