An automatic marking device for weld defects of an ultra-large LNG cryogenic storage tank

Abstract

The application discloses an automatic marking device for weld defects of an ultra-large LNG cryogenic storage tank and belongs to the technical field of nondestructive testing of the ultra-large storage tank. The technical scheme adopted by the application is as follows: the application provides an automatic marking device for weld defects of an ultra-large LNG cryogenic storage tank, which comprises a moving unit, a marking executor and a receiving unit. The moving unit is used for driving the device to move along the horizontal direction and the vertical direction of the wall of the storage tank. The marking executor is used for forming marks on the outer wall of the storage tank. The receiving unit is used for receiving defect position information sent by an external detection system. The moving unit and the marking executor are controlled by automatically receiving the defect position information and combining real-time positioning data, so that accurate positioning and automatic marking are realized. The automatic marking device can realize high-precision automatic marking, the positioning precision is improved to the level of the detection device, manual high-altitude operation time is significantly reduced, and the marking efficiency and safety are improved.

Description

Technical Field

[0001] This invention belongs to the field of non-destructive testing technology for ultra-large storage tanks, specifically relating to an automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks. Background Technology

[0002] As a critical energy storage facility, ultra-large LNG cryogenic storage tanks typically have a single tank volume exceeding 160,000 cubic meters. The butt welds on the tank walls, encompassing both circumferential and longitudinal welds, must undergo 100% digital radiographic inspection to identify internal defects such as porosity, inclusions, lack of fusion, and cracks. When the inspection system determines that a defect exceeds safety standards, a clear mark must be made at the corresponding location on the tank's outer wall to ensure that subsequent repair personnel can accurately identify and perform repair welding operations.

[0003] Current marking practices mainly rely on manual methods. Inspectors first identify defects based on digital X-ray images, and then estimate the horizontal distance and vertical height of the defects on the tank wall by combining image scale parameters and data recorded by the encoder of the walking device. They then carry tools such as markers, spray paint cans or steel stamps and climb back to the estimated location to mark the defects.

[0004] This manual operation mode faces multiple technical obstacles: Positioning accuracy is severely insufficient. Due to perspective deviations when manually reading encoder data, recording errors, and positioning errors of the walking device, the deviation between the actual marked position and the true defect location often exceeds ±50mm, far exceeding the ±5mm encoder accuracy of the detection device itself. This forces repair personnel to repeatedly perform X-ray or ultrasonic testing to confirm the exact defect location, significantly hindering repair efficiency. The markings lack durability and information carrying capacity. Ordinary markers or paint are prone to fading, peeling, or blurring in the outdoor, extreme low-temperature (-196℃), and weathering environments where storage tanks are located, failing to maintain long-term legibility. Furthermore, manual marking is limited by tool characteristics and operating space, providing only simple serial numbers or arrow symbols, without… The inability to record key parameters such as defect type, length, and depth severely hinders the quality traceability process. While steel stamp marking provides some durability, it creates permanent indentations on the metal surface, leading to stress concentration risks and damaging the anti-corrosion coating. The integrity of the anti-corrosion coating directly affects the safe service life of LNG cryogenic storage tanks, thus this method is strictly limited in engineering specifications. The separation of the inspection and marking processes forces inspectors to climb tanks over 38 meters high to mark the defects after completing the inspection, significantly extending the time spent working at height and significantly increasing the safety risks of falls and being struck by objects. In addition, when faced with multiple defects densely distributed on the weld, manual methods cannot achieve batch processing; each defect must be recorded, searched, and marked individually, making the operation lengthy and prone to omissions.

[0005] The aforementioned problems collectively restrict the timeliness and reliability of defect handling, and there is an urgent need to develop a solution that can be linked with digital X-ray inspection systems in real time, automatically receive defect coordinates, accurately locate and perform non-destructive marking. Summary of the Invention

[0006] This invention provides an automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks to solve at least one of the above-mentioned technical problems.

[0007] The technical solution adopted in this invention is as follows: An automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks includes: The moving unit is used to drive the device to move horizontally and vertically along the tank wall; A marking actuator used to create marks on the outer wall of a storage tank; The receiving unit is used to receive defect location information sent by an external detection system; The positioning unit is used to acquire the two-dimensional coordinates or walking displacement of the mobile unit on the tank wall in real time. The controller is electrically connected to the moving unit, the marking actuator, the receiving unit, and the positioning unit, respectively. Based on the defect location information received by the receiving unit and the location data fed back by the positioning unit, the controller controls the moving unit to move the marking actuator to the coordinate point indicated by the defect location information and drives the marking actuator to perform marking.

[0008] Furthermore, this application also proposes that the moving unit includes a horizontal walking module and a vertical lifting module, wherein the horizontal walking module is used to move horizontally along the tank wall and the vertical lifting module is used to lift vertically along the tank wall.

[0009] Furthermore, this application also proposes that the positioning unit includes an encoder for measuring horizontal walking distance and a stepper motor pulse counting module for measuring vertical lifting height.

[0010] Furthermore, this application also proposes that the marking actuator is a fully automatic inkjet printer.

[0011] Furthermore, this application also proposes that the receiving unit is a wireless communication module, which includes a PLC wireless module and / or a 4G / 5G signal amplifier.

[0012] Furthermore, this application also proposes to include a telescopic drive mechanism electrically connected to the controller, with the marking actuator installed at the output end of the telescopic drive mechanism, the telescopic drive mechanism being used to drive the marking actuator closer to or away from the tank wall.

[0013] Furthermore, this application also proposes to include a rotary drive mechanism electrically connected to the controller, with the marking actuator mounted at the output end of the rotary drive mechanism, the rotary drive mechanism being used to drive the marking actuator to switch between the horizontal marking direction and the vertical marking direction.

[0014] Furthermore, this application also proposes to include a crosshair laser electrically connected to the controller for projecting a crosshair onto the tank wall before marking to assist in confirming the position.

[0015] Furthermore, this application also proposes to include a wireless camera for real-time capture of the working area and marking effect of the marking actuator, and transmit the video signal to a remote monitoring terminal via wireless means.

[0016] Furthermore, this application also proposes that the controller has a defect coordinate queue storage area for storing multiple unmarked defect coordinates in sequence and automatically executing the marking task in order.

[0017] Due to the adoption of the above technical solution, the beneficial effects achieved by this invention are as follows: 1. By measuring the horizontal travel distance using an encoder in the positioning unit and the vertical lifting height using a stepper motor pulse counting module, and coordinating with a controller for closed-loop control, and aided by a crosshair laser to project a crosshair for alignment, this device can automatically move the marking actuator to the defect coordinate point, reducing positioning errors. Repair personnel can directly perform welding based on the markings without needing to re-inspect to confirm the defect location, significantly improving repair efficiency.

[0018] 2. A fully automatic inkjet printer is used as the marking actuator. It forms a permanent mark on the outer wall of the storage tank by non-contactly spraying a special low-temperature and weather-resistant ink. This method does not damage the anti-corrosion layer or the metal substrate and can withstand LNG operating conditions as low as -196 degrees Celsius. The marking content is programmable, supporting the printing of detailed information such as QR codes, defect types, length, and depth. This solves the problems of traditional markings being prone to fading and having limited information content, providing a reliable basis for quality traceability.

[0019] 3. The marking actuator is automatically moved to the defect coordinates by the horizontal walking module and vertical lifting module in the mobile unit. With the help of the wireless communication module, it receives the defect location information sent by the external detection system, and the wireless camera remotely monitors the marking process in real time. The entire process does not require manual secondary climbing of the storage tank, completely avoiding safety accidents such as falls and falling objects that may be caused by high-altitude operations in traditional manual marking.

[0020] 4. Enables automated batch marking of multiple defects, avoiding omissions. The controller has a defect coordinate queue storage area, which can store multiple unmarked defect coordinates sequentially and automatically execute the marking task in order. When multiple defects exist on a weld, the external detection system can continuously send all defect coordinates, and this device will automatically queue and process them, eliminating the need for manual intervention or repeated walking, effectively solving the problems of easy omissions and low efficiency in batch marking.

[0021] 5. Through real-time linkage between the receiving unit and the external digital X-ray inspection system, the controller automatically plans the optimal path after acquiring the defect coordinates, drives the telescopic drive mechanism to adjust the marking distance, and the rotary drive mechanism to switch between horizontal and vertical marking directions. The marking effect is then transmitted back in real-time by a wireless camera for remote confirmation. The entire process achieves an automated closed loop from defect identification to physical marking, reducing the time required for traditional separate inspection and marking operations (from several hours or even days) to minutes. Simultaneously, visual feedback ensures reliable marking quality. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of a specific embodiment of the present invention; Figure 2 This is a schematic diagram of the automatic marking device of the present invention; Figure 3 For the present invention Figure 2 Enlarged view of a local structure in the middle; Figure 4 This is a flowchart of the control logic for the automatic defect marking device of the present invention. Figure 5 This is a system composition and data flow diagram of the automatic defect marking device of the present invention.

[0023] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0024] In the attached diagram: 1. Horizontal walking module; 2. Vertical lifting module; 3. Marking actuator; 4. Wireless communication module; 5. Telescopic drive mechanism; 6. Rotary drive mechanism; 7. Controller; 8. Cross laser; 9. Wireless camera; 10. Encoder; 11. Pulse counting module. Detailed Implementation

[0025] To more clearly illustrate the overall concept of the present invention, a detailed description will be provided below with reference to the accompanying drawings and examples.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0027] Furthermore, in the description of this invention, it should be understood that the terms "top," "bottom," "inner," "outer," "axial," "radial," "circumferential," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "aspect," "specific example," or "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0030] Traditional methods for marking weld defects in ultra-large LNG cryogenic storage tanks primarily rely on manual operation, which suffers from problems such as positioning errors, easy damage to markers, limited information capacity, structural damage risks, risks associated with working at heights, and difficulties in batch processing. These issues affect the efficiency of repair operations, increase operational risks, and hinder quality traceability.

[0031] Reference Figures 1-5This application proposes an automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks. The device includes a moving unit for moving the device horizontally and vertically along the tank wall; a marking actuator 3 for forming marks on the outer wall of the tank; a receiving unit for receiving defect location information sent by an external detection system; a positioning unit for acquiring the two-dimensional coordinates or displacement of the moving unit on the tank wall in real time; and a controller 7 electrically connected to the moving unit, marking actuator 3, receiving unit, and positioning unit. Based on the defect location information received by the receiving unit and the position data fed back by the positioning unit, the controller 7 controls the moving unit to move the marking actuator 3 to the coordinate point indicated by the defect location information and drives the marking actuator 3 to perform the marking.

[0032] For ease of understanding, the following explains some key terms in this embodiment: The moving unit is configured to enable the entire marking device to move in two dimensions along the outer wall of the ultra-large LNG cryogenic storage tank. This movement may include horizontal movement along the circumference of the tank and vertical movement along the height of the tank to cover all potential weld areas on the tank wall.

[0033] The marking actuator 3 is used to create physical marks on the outer wall of the storage tank. These marks can be visible, identifiable symbols, text, or patterns, and their purpose is to indicate the location of defects for subsequent repair work.

[0034] The receiving unit is designed to establish a communication link with an external inspection system. Through this link, the weld defect location information identified and processed by the external inspection system can be transmitted to this device as instruction input for the marking operation.

[0035] The positioning unit is used to continuously monitor and provide position data of the moving unit on the tank wall. This data can be absolute two-dimensional coordinates, such as the XY coordinates relative to a fixed reference point on the tank, or it can be the amount of travel displacement relative to the initial position, such as the cumulative distance in the horizontal direction and the cumulative height in the vertical direction.

[0036] The controller 7 is the central processing unit of the entire device. It is configured to receive and process defect location information from the receiving unit and position data from the positioning unit. Based on these inputs, the controller 7 can generate control commands to coordinate the movement of the moving unit and the action of the marking actuator 3, thereby achieving automatic defect location and marking.

[0037] This embodiment provides an automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks. The device includes a moving unit configured to drive the entire device to move horizontally and vertically along the tank wall. For example, the moving unit can consist of a series of suction cups and drive wheels, moving by adhering to the tank wall and driving the wheels to rotate; or it can consist of a magnetic adsorption mechanism and tracks, magnetically adhering to the metal tank wall and being driven by the tracks.

[0038] The marking actuator 3 is used to form marks on the outer wall of the storage tank. The marking actuator 3 can be an inkjet printhead that forms marks on the surface of the storage tank by jetting ink; or it can be a laser etching device that forms shallow scratches on the surface of the storage tank as marks by using a laser beam.

[0039] The receiving unit is used to receive defect location information sent by an external inspection system. This receiving unit can be a wired communication interface, such as an Ethernet interface or an RS485 interface, connected to the external inspection system via a physical cable to receive data; alternatively, it can be a wireless communication module, such as a Bluetooth module or a Wi-Fi module, receiving defect location data from the external inspection system via radio waves.

[0040] The positioning unit is used to acquire the two-dimensional coordinates or displacement of the mobile unit on the tank wall in real time. The positioning unit can consist of an inertial measurement unit (IMU) that estimates the relative displacement of the device by integrating an accelerometer and a gyroscope; or it can consist of a vision positioning system that calculates the real-time position of the device by analyzing the texture or preset markings on the tank wall.

[0041] The controller 7 is electrically connected to the moving unit, the marking actuator 3, the receiving unit, and the positioning unit, respectively. The controller 7 can be an embedded microcontroller, such as an ARM-based processor, which runs a preset control program; or it can be an industrial PC that runs an operating system and application software to manage the various modules.

[0042] Specifically, the controller 7, based on the defect location information received by the receiving unit and the location data fed back by the positioning unit, controls the moving unit to move the marking actuator 3 to the coordinate point indicated by the defect location information, and drives the marking actuator 3 to perform marking. For example, when the receiving unit receives the defect coordinates (X, Y), the controller 7 compares the deviation between the device position (x, y) fed back by the current positioning unit and the target position (X, Y), and then calculates the horizontal and vertical movement required by the moving unit. Subsequently, the controller 7 sends a command to the moving unit to move along the calculated path. Once the positioning unit reports that the device has reached the vicinity of the target coordinate point, the controller 7 activates the marking actuator 3, causing it to form a mark on the tank wall.

[0043] This device integrates a moving unit, a marking actuator 3, a receiving unit, a positioning unit, and a controller 7 to automate the marking of weld defects in ultra-large LNG cryogenic storage tanks. This solution avoids the problems of positioning errors, insufficient marking durability, and high-altitude operation risks inherent in traditional manual marking methods. The automated process improves the efficiency of defect marking, reduces safety risks for workers, and provides a location reference for subsequent repair work.

[0044] Reference Figures 1-5 This application further proposes that the moving unit of the above-mentioned device includes a horizontal walking module 1 and a vertical lifting module 2, wherein the horizontal walking module 1 is used to move horizontally along the tank wall, and the vertical lifting module 2 is used to lift vertically along the tank wall.

[0045] Specifically, the moving unit is the actuator that moves the entire marking device along the tank wall. To achieve precise two-dimensional movement of the device on the tank wall, the moving unit is designed to include two independent but cooperative sub-modules. The horizontal walking module 1 is specifically responsible for moving the device horizontally along the tank wall. This module can be implemented in various ways. For example, it can consist of a set of magnetic wheels with a drive motor, with the motor speed and direction precisely controlled by the controller 7, allowing the device to move smoothly along the circumference of the tank. In another implementation, the horizontal walking module 1 can also use a suction cup or vacuum adsorption mechanism in conjunction with a linear actuator to perform step-by-step horizontal movement on the tank surface. The vertical lifting module 2 is specifically responsible for lifting the device vertically along the tank wall. This module can be implemented in ways including, but not limited to: using a rack and pinion mechanism, with a motor driving the gears to move up and down along a rack fixed to the device; or using a screw and nut mechanism, with the screw rotating to drive the nut and connected device to perform vertical displacement; or using a wire rope winch system, with the winch controlling the lifting of the device. These implementation methods all ensure that the vertical lifting module 2 achieves accurate and stable vertical positioning under the command of the controller 7.

[0046] By employing the aforementioned technical solution, the mobile unit is decomposed into independent horizontal walking module 1 and vertical lifting module 2, making the two-dimensional movement control of the device on the wall of an ultra-large LNG cryogenic storage tank more precise and efficient. When the receiving unit receives defect location information sent by the external detection system, the controller 7 can calculate the required horizontal and vertical displacements based on this information and the real-time position data fed back by the positioning unit. Subsequently, the controller 7 can independently drive the horizontal walking module 1 and the vertical lifting module 2 to perform horizontal movement and vertical lifting tasks respectively, thereby precisely moving the marking actuator 3 to the coordinate point indicated by the defect location information. This modular design avoids the coupling errors and control complexity that may occur when a single moving mechanism performs two-dimensional positioning in a complex curved surface environment, significantly improving positioning accuracy and response speed. Simultaneously, the independent horizontal and vertical movement capabilities allow the device to more flexibly adapt to storage tanks of different shapes and sizes and optimize the movement path, thereby improving the overall efficiency and reliability of the marking operation.

[0047] Reference Figures 1-5 This application further proposes that the positioning unit includes an encoder 10 for measuring horizontal walking distance and a stepper motor pulse counting module 11 for measuring vertical lifting height.

[0048] Specifically, encoder 10 is a sensor that converts mechanical motion into electrical signals, used here to accurately measure the horizontal travel distance of the moving unit on the tank wall. Encoder 10 can be an incremental or absolute encoder. Incremental encoders represent displacement by outputting pulse signals, the number of pulses being proportional to the displacement. They are typically used in conjunction with a measuring wheel that contacts and rolls against the tank wall, and encoder 10 detects the rotation of the measuring wheel. Absolute encoders, on the other hand, directly output digital codes corresponding to the position, retaining position information even after power failure. Encoder 10 can be mounted on the drive shaft of the horizontal travel module 1, or indirectly measured via a measuring wheel in contact with the tank wall. To ensure accurate horizontal positioning, encoder 10 needs to have high resolution to accommodate the size and precision requirements of ultra-large tanks.

[0049] Meanwhile, the stepper motor pulse counting module 11 is used to measure the vertical lifting height. A stepper motor is an actuator that converts electrical pulse signals into angular displacement, and its rotation angle strictly corresponds to the number of pulses received. The vertical lifting module 2 is typically driven by a stepper motor, achieving vertical movement through transmission mechanisms such as gears, lead screws, or chains. The stepper motor pulse counting module 11 records the number of pulses received by the stepper motor, and the actual vertical displacement of the vertical lifting module 2 can be accurately calculated using a preset step angle and transmission ratio. This measurement method utilizes the high precision and repeatability of the stepper motor itself, achieving precise displacement control and measurement without the need for additional displacement sensors. To ensure the absolute accuracy of the vertical height measurement, initial position calibration is usually required using limit switches or zero-position sensors.

[0050] Through the above technical solution, the positioning unit can utilize the encoder 10 to provide high-precision horizontal displacement feedback, ensuring the positioning accuracy of the moving unit in the horizontal direction. Simultaneously, the stepper motor pulse counting module 11 records the number of pulses from the stepper motor to achieve precise vertical height measurement. This combination provides the controller 7 with high-precision, high-reliability two-dimensional coordinates or walking displacement data, enabling the controller 7 to accurately guide the marking actuator 3 to the coordinate point indicated by the defect location information. This significantly improves the accuracy and efficiency of automatic marking of weld defects in ultra-large LNG cryogenic storage tanks, effectively avoiding missed or incorrect markings due to inaccurate positioning, reducing manual intervention and errors, and is particularly suitable for ultra-large storage tank inspection scenarios with extremely high precision requirements.

[0051] Reference Figures 1-5 This application further proposes that the marking actuator 3 is a fully automatic inkjet printer. A fully automatic inkjet printer is a device capable of automatically completing the marking process, typically integrating functions such as ink supply, printing control, and position adjustment. Specifically, the fully automatic inkjet printer can accurately spray ink or special marking liquid onto designated positions on the tank wall without manual intervention, forming clear and durable marks, based on instructions sent by the controller 7. Its working principle typically involves spraying ink droplets at high speed onto the target surface through a nozzle, and controlling the droplet landing point through methods such as charge deflection or piezoelectric effect, thereby forming characters, graphics, or dot matrices. In the application scenario of automatic marking of weld defects in ultra-large LNG cryogenic storage tanks, the fully automatic inkjet printer can achieve non-contact marking, avoiding physical damage to the tank surface, while also possessing advantages such as high marking speed, programmable marking content, and adaptability to different surface materials. Furthermore, fully automatic inkjet printers typically have a high degree of automation and stability, meeting the needs of long-term continuous operation, and can adjust printing parameters as needed to adapt to different environmental conditions and marking requirements.

[0052] By specifically configuring the marking actuator 3 as a fully automatic inkjet printer, this application effectively solves the problems of low efficiency, unstable marking quality, and difficulty in adapting to large-scale continuous operations in the automatic marking of weld defects in ultra-large LNG cryogenic storage tanks using traditional marking methods. Specifically, after receiving defect location information and combining it with position data fed back by the positioning unit, the controller 7 can directly drive the fully automatic inkjet printer to move to the precise defect coordinate point. With its non-contact, high-speed, and high-precision printing capabilities, the fully automatic inkjet printer can quickly and accurately form clear and durable marks on the outer wall of the storage tank without manual intervention, significantly improving the automation level and operational efficiency of marking. At the same time, the programmable nature of the fully automatic inkjet printer allows for flexible adjustment of the marking content, such as including defect type and date information, thereby improving the precision of defect management. This configuration ensures the continuity, stability, and reliability of marking operations in the special environment of ultra-large LNG cryogenic storage tanks, providing accurate guidance for subsequent defect handling.

[0053] Reference Figures 1-5 This application further proposes that the receiving unit is a wireless communication module 4, which includes a PLC wireless module and / or a 4G / 5G signal amplifier.

[0054] The wireless communication module 4, acting as a receiving unit, primarily functions to enable wireless data transmission between the device and an external detection system. It exchanges information via radio waves, avoiding many limitations of traditional wired connections, such as complex wiring, susceptibility to physical damage, and cable wear and tangling during movement. This module typically includes RF transceiver circuitry, baseband processing circuitry, and a corresponding protocol stack, capable of demodulating the received wireless signals into digital data and transmitting it to the controller 7 for processing.

[0055] PLC wireless modules are a type of wireless communication based on Power Line Communication (PLC) technology. They utilize existing power lines as the transmission medium, modulating data signals onto the power lines for transmission. In industrial environments, especially in large storage tank areas, power lines are typically already laid, thus PLC wireless modules can avoid additional wiring, reducing deployment costs and complexity. They feature strong anti-interference capabilities, relatively long transmission distances, and good obstacle penetration, making them suitable for industrial scenarios requiring stable and reliable data transmission.

[0056] 4G / 5G signal amplifiers are used to enhance the signal strength and coverage of mobile communication networks (such as 4G or 5G). At the operating site of ultra-large LNG cryogenic storage tanks, mobile communication signals may be weak due to the metal structure of the tank itself or obstructions from the surrounding environment, leading to unstable or interrupted data transmission. The signal amplifier receives weak external signals, amplifies them, and then retransmits them, effectively improving the signal quality in the area where the device is located, ensuring that the wireless communication module 4 can stably receive defect location information from external detection systems. It typically includes an outdoor antenna, an indoor antenna, and a signal enhancement host.

[0057] By configuring the receiving unit as a wireless communication module 4 and further employing a PLC wireless module and / or a 4G / 5G signal amplifier, this application effectively solves the problem of unstable and inefficient transmission of defect location information in the complex operating environment of ultra-large LNG cryogenic storage tanks. Specifically, the wireless communication module 4 eliminates the limitations of wired connections, enabling the device to flexibly and unimpededly receive defect location information sent by external detection systems when moving horizontally and vertically on the tank wall. The PLC wireless module utilizes existing power lines for data transmission, avoiding additional wiring and providing strong anti-interference capabilities and transmission stability, making it particularly suitable for industrial sites. Meanwhile, the 4G / 5G signal amplifier effectively enhances signal strength and coverage in areas where mobile communication signals may be weak, ensuring the reliability of data transmission. This allows the controller 7 to stably and accurately receive defect location information. Combined with the location data fed back by the positioning unit, it precisely controls the moving unit to move the marking actuator 3 to the defect location and drives the marking actuator 3 to perform marking, thereby significantly improving the efficiency and accuracy of automatic defect marking and reducing manual intervention and maintenance costs.

[0058] Reference Figures 1-5 Furthermore, this application proposes that the device also includes a telescopic drive mechanism 5 electrically connected to the controller 7, and a marking actuator 3 is installed at the output end of the telescopic drive mechanism 5. The telescopic drive mechanism 5 is used to drive the marking actuator 3 to move closer to or away from the tank wall.

[0059] Specifically, the telescopic drive mechanism 5 is a mechanical device capable of providing linear telescopic motion, its function being to precisely adjust the working distance between the marking actuator 3 and the tank wall. This telescopic drive mechanism 5 can be implemented in various forms; for example, it can be an electric linear actuator, internally containing a motor, a lead screw, and a nut mechanism, where the motor's rotation drives the lead screw, thereby achieving linear reciprocating motion at the output end; it can also be a pneumatic or hydraulic cylinder, using controlled air or hydraulic pressure to drive the piston rod to extend or retract. The output end of the telescopic drive mechanism 5 is the part that provides linear motion, and the marking actuator 3 is securely mounted on this output end, ensuring that the motion of the telescopic drive mechanism 5 can be directly transmitted to the marking actuator 3. This mounting method allows the marking actuator 3 to move as a whole with the telescopic drive mechanism 5, thereby adjusting the distance between it and the tank wall. The controller 7 communicates with the telescopic drive mechanism 5 via an electrical connection, and can send control commands to the telescopic drive mechanism 5, such as commands to extend, retract, or stop at a specific position. With the precise control of the controller 7, the telescopic drive mechanism 5 can drive the marking actuator 3 to approach or move away from the tank wall in a controlled manner, so as to adapt to the irregularity or curvature change of the tank wall surface and ensure that the marking actuator 3 is always at the optimal working distance.

[0060] Through the above technical solution, the telescopic drive mechanism 5, under the precise control of the controller 7, can adjust the distance between the marking actuator 3 and the tank wall in real time. This allows the marking actuator 3 to adapt to the unevenness or curvature changes of the tank wall surface, always maintaining the optimal marking distance, thereby ensuring the clarity, accuracy, and consistency of the markings. At the same time, it effectively avoids wear or damage to the marking actuator 3 caused by improper distance, significantly improving the marking quality, operational stability, and service life of the device.

[0061] Reference Figures 1-5 This application further proposes that the device also includes a rotary drive mechanism 6 electrically connected to the controller 7, and the marking actuator 3 is installed at the output end of the rotary drive mechanism 6. The rotary drive mechanism 6 is used to drive the marking actuator 3 to switch between the horizontal marking direction and the vertical marking direction.

[0062] The rotary drive mechanism 6 is an actuator that provides rotary motion, its main function being to change the posture or orientation of the marking actuator 3. This mechanism can be implemented in various forms. For example, it can be a rotary platform driven by a stepper motor or servo motor, achieving precise angle adjustment of the marking actuator 3 by accurately controlling the motor's rotation angle. Alternatively, it can be a mechanical structure containing transmission components such as gears, belts, or linkages, driven by an external power source (such as a small DC motor) to transmit rotary motion to the marking actuator 3. The rotary drive mechanism 6 typically integrates a position sensor (such as an encoder or limit switch) so that the controller 7 can acquire its rotation angle or current posture in real time, ensuring that the marking actuator 3 can accurately switch to the preset marking direction.

[0063] The marking actuator 3 is installed at the output end of the rotary drive mechanism 6, meaning that the marking actuator 3 is mechanically fixed to the rotating component of the rotary drive mechanism 6. This installation method ensures that the marking actuator 3 can change its spatial orientation as the rotary drive mechanism 6 moves. Specific installation methods may include, but are not limited to, fixing the marking actuator 3 to the rotating shaft, rotating disk, or connecting arm of the rotary drive mechanism 6 using bolts, clips, or quick-connect mechanisms. This connection needs to have sufficient mechanical strength and stability to withstand the vibration and reaction forces of the marking actuator 3 during operation, while ensuring positioning accuracy during rotational switching.

[0064] The core function of the rotary drive mechanism 6 is to precisely adjust the printing or marking direction of the marking actuator 3 according to the instructions of the controller 7. For example, when horizontal marking is required, the rotary drive mechanism 6 will rotate the marking actuator 3 so that its nozzles or marking heads are aligned horizontally; when vertical marking is required, it will rotate it so that they are aligned vertically. This switching typically involves a 90-degree rotation, but other angles can be adjusted according to actual needs. The controller 7 sends control signals to the rotary drive mechanism 6 through a preset program or based on received defect information, causing it to execute the corresponding rotation action, thereby achieving automated switching of the marking direction.

[0065] Through the above technical solution, a rotary drive mechanism 6 is introduced and electrically connected to the controller 7. The marking actuator 3 can be installed at the output end of the rotary drive mechanism 6. The controller 7 can drive the rotary drive mechanism 6 to switch the marking actuator 3 between the horizontal and vertical marking directions according to the actual direction of the defect or the preset marking requirements. For example, when the defect location information sent by the external detection system indicates that the defect extends horizontally, the controller 7 can instruct the rotary drive mechanism 6 to adjust the marking actuator 3 to the horizontal marking direction for printing; when the defect extends vertically, it is adjusted to the vertical marking direction. This design allows the marking actuator 3 to flexibly adapt to the marking needs of weld defects in different directions, avoiding the problems of inaccurate marking or the need for manual intervention caused by a single marking direction. This significantly improves the automation level and marking accuracy of the device, ensuring that defect information can be clearly and accurately presented on the outer wall of the storage tank, thereby providing convenience for subsequent maintenance or inspection work and improving overall work efficiency and reliability.

[0066] Reference Figures 1-5 This application further proposes that the device also includes a cross laser 8 electrically connected to the controller 7, for projecting a crosshair onto the tank wall before marking to assist in confirming the position.

[0067] Specifically, the cross laser 8 is a device capable of projecting a clear cross-shaped laser cursor. The cross laser 8 can consist of two mutually perpendicular laser diodes, each of which expands the laser beam into a line through a cylindrical lens or diffractive optical element, the two lines intersecting to form a cross; alternatively, it can be a single laser diode combined with a special diffractive optical element to directly generate the cross cursor. The cross laser 8 is precisely installed near the marking actuator 3, ensuring that the center point of its projected cross cursor coincides with the predetermined mark center point of the marking actuator 3. The controller 7 controls the opening and closing of the cross laser 8 via electrical connection, enabling it to project the cross cursor onto the tank wall at the appropriate time before the marking actuator 3 performs the marking action.

[0068] Through the above technical solution, before the marking actuator 3 performs the actual marking, the crosshair laser 8 projects a clearly visible crosshair onto the tank wall, precisely indicating the center position to be marked. This allows operators or remote monitoring systems to visually confirm in real time whether the marking actuator 3 has accurately aligned with the defect location. If a slight deviation is observed between the crosshair and the defect center, necessary fine-tuning can be performed by the controller 7 before the marking action, effectively correcting potential marking deviations caused by mechanical errors, surface unevenness, or inherent accuracy limitations of the positioning system. Therefore, this technical solution greatly improves the accuracy and reliability of defect marking, ensuring that each mark accurately corresponds to the actual defect point, providing a solid foundation for subsequent defect verification, repair, quality control, and data traceability. It significantly improves the overall efficiency and accuracy of operations, avoiding additional workload or misjudgment risks that may result from inaccurate marking.

[0069] Reference Figures 1-5 This application further proposes that the device also includes a wireless camera 9, used to capture the working area and marking effect of the marking actuator 3 in real time, and transmit the video signal to a remote monitoring terminal.

[0070] Specifically, the wireless camera 9 is an imaging device capable of capturing image or video data and transmitting it wirelessly. The camera 9 is configured to monitor the working status, marking process, and marking effect of the marking actuator 3 in real time. To adapt to the operating environment of ultra-large LNG cryogenic storage tanks, the wireless camera 9 can be an industrial-grade camera with explosion-proof and cryogenic resistance characteristics. Its wireless transmission module can employ various wireless communication technologies, such as Wi-Fi, Bluetooth, 4G, or 5G, to ensure the stability and real-time performance of video data transmission. The installation position of the wireless camera 9 is carefully designed to ensure that its field of view clearly covers the nozzle or marking point of the marking actuator 3 and accurately captures the image marked on the tank wall. By capturing the working area and marking effect of the marking actuator 3 in real time, the device provides immediate and intuitive visual feedback, allowing operators to remotely confirm whether the marking actuator 3 is working in the correct position and verify whether the formed marking is clear, complete, and accurate. Subsequently, the wireless camera 9, through its built-in or external wireless communication module, encodes and compresses the captured video data and transmits it wirelessly to a remote monitoring terminal located in a safe area. The remote monitoring terminal can be a computer, tablet computer, or dedicated monitoring equipment equipped with a display screen, which can receive, decode, and display video streams in real time, allowing operators to remotely observe the marking process and results without being physically present on-site.

[0071] Through the above technical solution, this application, based on the automatic defect location and marking, further introduces real-time visual monitoring functionality. The wireless camera 9 can transmit the working area and marking effect of the marking actuator 3 to a remote monitoring terminal in real time, enabling operators to remotely and intuitively understand the progress and quality of the marking operation. This effectively solves the problem of traditional automatic marking devices lacking real-time feedback and difficulty in immediately confirming the marking effect during remote operations. Operators can remotely confirm whether the device has accurately moved to the defect location, whether the marking actuator 3 is working properly, and whether the marking is clear and complete. Once an abnormality or error in marking is detected, immediate remote intervention or adjustment can be performed, avoiding the need for repetitive work or subsequent manual re-inspection due to unqualified marking, significantly improving the efficiency, accuracy, and safety of the marking operation. Simultaneously, real-time video monitoring also provides a traceable visual record of the operation process, further enhancing the reliability of the entire defect management process.

[0072] Reference Figures 1-5 This application further proposes that the controller 7 includes a defect coordinate queue storage area for sequentially storing multiple unmarked defect coordinates and automatically executing marking tasks in sequence. Specifically, the defect coordinate queue storage area is a memory region within the controller 7, designed to temporarily or permanently store defect location information to be processed. This storage area is typically implemented using data structures such as First-In-First-Out (FIFO) or Priority Queue to ensure that defect coordinates can be managed and scheduled according to preset logic. This storage area can be part of the controller 7's internal RAM, EEPROM, or flash memory, used to store the two-dimensional coordinate data of defect points received from the receiving unit that have not yet been marked.

[0073] When the receiving unit receives defect location information from an external detection system, the controller 7 does not immediately process each defect. Instead, it stores the coordinate data of these defects one by one into the defect coordinate queue storage area according to the receiving order or other preset priority rules, thereby storing multiple unmarked defect coordinates sequentially. This storage method allows the system to receive and manage defect information in batches without interrupting the current task for processing immediately after receiving each defect information. When there are unmarked defect coordinates in the defect coordinate queue storage area, the controller 7 automatically retrieves the next defect coordinate from the queue according to the storage order (e.g., first-in, first-out). Subsequently, the controller 7, combined with the position data fed back by the positioning unit, controls the moving unit to move the marking actuator 3 to the position indicated by the defect coordinate and drives the marking actuator 3 to perform the marking operation. After marking the current defect, the controller 7 automatically retrieves the next defect coordinate from the queue and repeats the above process until all defects in the queue are marked, thereby achieving automatic sequential execution of the marking task. This automated and sequential execution method greatly improves the continuity and efficiency of the marking operation.

[0074] Through the above technical solution, a defect coordinate queue storage area is set up within the controller 7, enabling it to sequentially store multiple unmarked defect coordinates. This allows the device to achieve batch reception and management of defect information. When an external detection system detects multiple defects, their coordinate information can be continuously sent and stored in the queue without waiting for the previous defect to be marked. Subsequently, the controller 7 automatically retrieves the defect coordinates from the queue in sequence and drives the moving unit to precisely move the marking actuator 3 to the target position for marking. This mechanism avoids the tedious operation of requiring operators to input or confirm each defect location individually, significantly improving the automation and efficiency of the marking operation. Simultaneously, because the task is executed automatically in queue order, errors that may arise from human intervention are reduced, ensuring the accuracy and continuity of marking. This is particularly suitable for scenarios with a large number of defects and complex operating environments, such as ultra-large LNG cryogenic storage tanks.

[0075] For any parts not mentioned in this invention, existing technologies can be used or referenced.

[0076] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0077] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. An automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks, characterized in that, include: The moving unit is used to drive the device to move horizontally and vertically along the tank wall; A marking actuator (3) is used to form a mark on the outer wall of the storage tank; The receiving unit is used to receive defect location information sent by an external detection system; The positioning unit is used to acquire the two-dimensional coordinates or walking displacement of the mobile unit on the tank wall in real time. The controller (7) is electrically connected to the moving unit, the marking actuator (3), the receiving unit and the positioning unit respectively; The controller (7) controls the moving unit to move the marking actuator (3) to the coordinate point indicated by the defect location information received by the receiving unit and the position data fed back by the positioning unit, and drives the marking actuator (3) to perform marking.

2. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, The moving unit includes a horizontal walking module (1) and a vertical lifting module (2). The horizontal walking module (1) is used to move horizontally along the tank wall, and the vertical lifting module (2) is used to lift vertically along the tank wall.

3. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, The positioning unit includes an encoder (10) for measuring horizontal walking distance and a stepper motor pulse counting module (11) for measuring vertical lifting height.

4. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, The marking actuator (3) is a fully automatic inkjet printer.

5. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, The receiving unit is a wireless communication module (4), which includes a PLC wireless module and / or a 4G / 5G signal amplifier.

6. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, It also includes a telescopic drive mechanism (5) electrically connected to the controller (7), the marking actuator (3) is installed at the output end of the telescopic drive mechanism (5), and the telescopic drive mechanism (5) is used to drive the marking actuator (3) to move closer to or away from the tank wall.

7. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, It also includes a rotary drive mechanism (6) electrically connected to the controller (7), the marking actuator (3) is installed at the output end of the rotary drive mechanism (6), and the rotary drive mechanism (6) is used to drive the marking actuator (3) to switch between the horizontal marking direction and the vertical marking direction.

8. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, It also includes a cross laser (8) electrically connected to the controller (7) for projecting a crosshair onto the tank wall before marking to assist in confirming the position.

9. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, It also includes a wireless camera (9) for capturing the working area and marking effect of the marking actuator (3) in real time and transmitting the video signal to a remote monitoring terminal.

10. The automatic marking device for weld defects in ultra-large LNG cryogenic storage tanks according to claim 1, characterized in that, The controller (7) is equipped with a defect coordinate queue storage area, which is used to store multiple unmarked defect coordinates in sequence and automatically execute the marking task in sequence.

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